Meningitis posquirúrgica por Acinetobacter baumannii multirresistente. Actividad sinérgica in vivo de la asociación sulbactam/avibactam / Post-surgical meningitis due to multiresistant Acinetobacter baumannii. In vivo synergistic activity of the sulbactam/avibactam association

Acinetobacter baumannii (AB) es un bacilo gram negativo, no fermentador,con frecuencia oportunista, ubicuo en el medio ambiente, con capacidad para sobrevivir en condiciones medioambientales adversas promoviendo su persistencia y diseminación en diferentes áreas de un hospital. Ha sido relacionado con múltiples brotes de infecciones asociadas al cuidado de la salud como neumonía, bacteriemias, contaminación de heridas quirúrgicas o infecciones del tracto urinario, especialmente entre pacientes con comorbilidades graves, como aquellos que motivan el ingreso a unidades de cuidados intensivos (UCI). Las cepas más problemáticas son aquellas resistentes a los carbapenémicos, resistencia causada por enzimas de la clase de las oxacilinasas (bla OXA) cromosómicas o plasmídicas y más recientemente bla NDM-1. La aparición de estas cepas deja escasos antimicrobianos activos (colistin, minociclina, tigeciclina; amikacina) que son limitados en su eficacia y su uso se asocia con toxicidad. A esto se agrega, como en la paciente que se describe, que desarrolló una meningitis posquirúrgica, la limitada capacidad de difusión en el sistema nervioso central (SNC) de estas últimas opciones. Una de las alternativas terapéuticas, es buscar asociaciones como sulbactam/avibactam que mostraron una adecuada actividad sinérgica y bactericida en asilamientos resistentes a ampicilina/sulbactam en base a una significativa reducción de la CIM que permite administrar dosis habituales, con mejor tolerancia y lograr concentraciones terapéuticas en SNC. Se presenta una paciente que desarrolló una meningitis posquirúrgica debida a una cepa de AB multirresistente.

Acinetobacter baumannii (AB) is a non-fermenting gram-negative bacillus, largely opportunistic, ubiquitous in the environment, with the ability to survive in adverse environmental conditions, promoting its persistence and dissemination in different areas of the hospital. It has been implicated in many outbreaks of healthcare-associated infections such as pneumonia, bacteremia, surgical wounds contamination, or urinary tract infections, especially among patients with previous severe illnesses such as those requiring admission to intensive care units (ICU). The most problematic strains are those resistant to carbapenems, resistance caused by chromosomal or plasmid oxacillinase class (bla OXA), and more recently bla NDM-1. The appearance of these strains leaves few active antimicrobials (Colistin, Minocycline, Tigecycline; Amikacin) that are limited in their efficacy and toxic. To this we must add, as is the case of our patient who presented post-surgical meningitis, the limited diffusion capacity in the central nervous system (CNS) of these last options. One of the therapeutic alternatives is to search for synergistic associations such as sulbactam/avibactam that showed rapid synergistic and bactericidal activity in isolates resistant to ampicillin/sulbactam due to a significant reduction in its MIC, which allows us to administer usual, better tolerated doses that reach therapeutic concentrations in CNS. Here, we present a patient who developed a post-surgical meningitis due to multiresistant AB

Regularity of ventilator-associated pneumonia induced by three common pathogens / 中华危重病急救医学

OBJECTIVE@#To investigate the incidence and infection regularity of ventilator-associated pneumonia (VAP) in patients undergoing tracheal intubation and to provide reference for the prevention and treatment of VAP infection in the future.@*METHODS@#A retrospective study was conducted to collect the microbial data of airway secretion cultures from 72 patients with endotracheal intubation admitted to the emergency ward of Shanghai Fifth People's Hospital from May 2020 to February 2021, and the species of microorganisms and intubation time were statistically analyzed.@*RESULTS@#Among 72 patients with endotracheal intubation, males were more than females (58.33% vs. 41.67%); Patients over 60 years old accounted for 90.28%; pneumonia was the main primary disease, accounting for 58.33%. Pathogenic tests showed that: (1) 72 patients were infected with Acinetobacter baumannii (AB), Klebsiella pneumoniae (KP), and Pseudomonas aeruginosa (PA) 48 hours after intubation, 51.39% (37/72), 27.78% (20/72), and 26.39% (19/72), respectively. The infection rate of AB was significantly higher than that of KP and PA. Within 48 hours of intubation, the infection rates of AB, KP, and PA were 20.83% (15/72), 13.89% (10/72), and 4.17% (3/72), respectively. Of the 42 patients with primary pneumonia, 61.90% (26/42) were infected with one or more of the three pathogenic bacteria AB, KP, and PA 48 hours after intubation, indicating a change in the etiology of the pathogenic bacteria, with the main pathogenic bacteria transitioning from other pathogenic bacteria to AB, KP, and PA. (2) AB, KP, and PA were prone to cause late onset VAP (i.e., intubation ≥ 5 days). Respectively, among VAP patients infected with AB, late onset VAP accounted for 59.46% (22/37). Among patients infected with KP, 75.00% (15/20) had late onset VAP. Among patients infected with PA, late onset VAP accounted for 94.74% (18/19), indicating a higher proportion of late onset VAP caused by PA and KP. (3) Infection was closely related to intubation time, and the pipeline can be replaced according to the peak period of infection. AB and KP infections peaked within 4 days after intubation, reaching 57.69% (30/52) and 50.00% (15/30), respectively. It is recommended to replace the tubes or undergo sensitive antimicrobial therapy around 3-4 days after starting the machine. The proportion of PA infection after 7 days of intubation was 72.73% (16/22), and it was considered to replace the pipeline after 7 days. (4) Most of the three pathogenic bacteria, AB, KP, and PA were carbapenem resistant pathogens with multiple drug resistance. Except for PA, the infection rate of carbapenem resistant bacteria (CRAB, CRKP) was significantly higher than that of non-carbapenem resistant bacteria (AB, KP), accounting for 86.54% (45/52) and 66.67% (20/30) of the corresponding infection cases, respectively, while CRPA only accounts for 18.18% (4/22).@*CONCLUSIONS@#The main differences in VAP infection caused by AB, KP, and PA pathogens are infection time, infection probability, and carbapenem resistance. Targeted prevention and treatment measures can be implemented for patients with intubation.

Ação antimicrobiana e antibiofilme dos extratos combinados de canela e própolis sobre cepas clínicas de Acinetobacter baumannii e Pseudomonas aeruginosa multirresistentes / Antimicrobial and antibiofilm action of combined extracts of cinnamon and propolis on multiresistant clinical strains of Acinetobacter baumannii and Pseudomonas aeruginosa

Os microrganismos resistentes a diferentes classes de agentes antimicrobianos têm se tornado cada vez mais comuns e atualmente são denominados como multirresistentes. Nos hospitais, tais microrganismos apresentam maior perigo, pois são causadores de infecções nosocomiais e a higienização bucal deficiente dos pacientes internados pode tornar a cavidade bucal um sítio para proliferação desses microrganismos multirresistentes. Diante do exposto, novos compostos com ação antimicrobiana precisam ser estudados. O objetivo deste estudo foi avaliar quimicamente o extrato hidroalcóolico de própolis verde de Baccharis dracunculifolia e de Cinnamomum verum (canela) que foram obtidos a partir da extração da matériaprima, analisar a atividade antimicrobiana e antibiofilme dos extratos isolados e combinados contra quatro cepas clínicas multirresistentes de Pseudomonas aeruginosa e Acinetobacter baumannii e verificar a citotoxicidade dos produtos vegetais in vitro em linhagem celular de queratinócitos humanos (HaCat). Para tanto, os extratos vegetais foram preparados a partir da matéria-prima da canela em casca e da própolis bruta. Em seguida, foram caracterizados quimicamente por cromatografia líquida de alta eficiência (HPLC-DAD) para identificação dos principais compostos e a análise do teor de sólidos solúveis dos extratos vegetais também foi realizada. Para avaliação antimicrobiana, foram performados o teste de microdiluição em caldo de acordo com a Clinical and Laboratory Standards Institute (CLSI) e a análise de Checkerboard, para avaliar o efeito combinado dos extratos. A atividade antibiofilme dos extratos combinados foi realizada por meio do teste de MTT, no qual diferentes tempos de contato (5 e 30 min) e diferentes modalidades (inibição na formação do biofilme bacteriano e erradicação do biofilme bacteriano já formado) foram testadas. Para ação citotóxica, as células foram cultivadas em meio DMEM e semeadas na placa de 96 poços. Após aderência inicial, aplicou-se os extratos em diferentes concentrações baseadas nas análises microbiológicas para avaliação da viabilidade celular por meio do teste de MTT. Os dados foram analisados por ANOVA e teste de Tukey, ou Kruskal-Wallis e Dunn, considerando um nível de significância de 5%. Os compostos identificados no extrato de própolis verde de B. dracunculifolia foram ácido clorogênico, derivado do ácido cinâmico e apigenina. O aldeído cinâmico foi o principal composto identificado no extrato de C. verum. Os extratos vegetais apresentaram ação bactericida sobre todas as cepas analisadas e, quando combinados, os extratos atuaram de modo aditivo e algumas combinações sinérgicas foram encontradas. O protocolo de inibição da formação do biofilme promoveu percentuais de redução superiores quando comparado ao protocolo de erradicação. Valores expressivos de 83,86% (p < 0,05) de inibição da formação de biofilme de uma cepa clínica de A. baumannii e 89,31% (p < 0,05) de inibição em uma cepa clínica de P. aeruginosa foram encontrados com a aplicação dos extratos combinados. A atuação dos produtos vegetais foi estatisticamente semelhante a atuação da clorexidina 0,12%. Em conclusão, os extratos de própolis verde e canela na forma isolada ou combinada apresentaram ação antimicrobiana e antibiofilme sobre cepas clínicas de A. baumannii e P. aeruginosa multirresistentes. Dessa forma, os produtos vegetais são promissores agentes antissépticos para futuras formulações odontológicas. (AU)

Microorganisms resistant to different classes of antimicrobial agents have become increasingly common and are currently called multidrug resistant. In hospitals, such microorganisms are more dangerous, as they cause nosocomial infections and poor oral hygiene in hospitalized patients can make the oral cavity a site for the proliferation of these multiresistant microorganisms. Given the above, new compounds with antimicrobial action need to be studied. The objective of this study was to chemically evaluate the hydroalcoholic extract of green propolis from Baccharis dracunculifolia and Cinnamomum verum (cinnamon) that were obtained from the extraction of the raw material, to analyze the antimicrobial and antibiofilm activity of the isolated and combined extracts against four clinical strains multiresistant strains of Pseudomonas aeruginosa and Acinetobacter baumannii and verify the cytotoxicity of plant products in vitro in human keratinocyte cell lineage (HaCat). For this purpose, plant extracts were prepared from raw cinnamon bark and raw propolis. Then, they were chemically characterized by high performance liquid chromatography (HPLC-DAD) to identify the main compounds and the analysis of the soluble solids content of the plant extracts was also performed. For antimicrobial evaluation, the broth microdilution test according to the Clinical and Laboratory Standards Institute (CLSI) and the Checkerboard analysis were performed to evaluate the combined effect of the extracts. The antibiofilm activity of the combined extracts was performed using the MTT test, in which different contact times (5 and 30 min) and different modalities (inhibition of bacterial biofilm formation and eradication of already formed bacterial biofilms) were tested. For cytotoxic action, cells were cultured in DMEM medium and seeded in the 96-well plate. After initial adhesion, the extracts were applied at different concentrations based on microbiological analyzes to assess cell viability through the MTT test. Data were analyzed by ANOVA and Tukey's test, or Kruskal-Wallis and Dunn, considering a significance level of 5%. The compounds identified in the green propolis extract of B. dracunculifolia were chlorogenic acid, cinnamic acid derivative and apigenin. Cinnamic aldehyde was the main compound identified in the C. verum extract. The plant extracts showed bactericidal action on all strains analyzed and, when combined, the extracts acted additively and some synergistic combinations were found. The biofilm formation inhibition protocol promoted higher reduction percentages when compared to the eradication protocol. Significant values of 83.86% (p < 0.05) inhibition of biofilm formation in a clinical strain of A. baumannii and 89.31% (p < 0.05) inhibition in a clinical strain of P. aeruginosa were found with the application of the combined extracts. The performance of plant products was statistically similar to the performance of 0.12% chlorhexidine. In conclusion, extracts of green propolis and cinnamon, in isolated or combined form, showed antimicrobial and antibiofilm action on multiresistant clinical strains of A. baumannii and P. aeruginosa. Thus, plant products are promising antiseptic agents for future dental formulations. (AU)

Extratos hidroetanólicos de canela (Cinnamomum verum) e romã (Punica granatum L) promovem ação antibacteriana frente cepas resistentes a antibióticos de Acinetobacter baumannii e Pseudomonas aeruginosa / Cinnamon (Cinnamomum verum) and pomegranate (Punica granatum L) hydroethanolic extracts promote antibacterial action against antibiotic-resistant strains of Acinetobacter baumannii and Pseudomonas aeruginosa

A resistência bacteriana tem aumentado progressivamente no mundo, assim, há necessidade de novas opções de tratamentos. A fitoterapia tem ganhado notoriedade para combater infecções, principalmente as causadas por bactérias resistentes aos antibacterianos disponíveis. Diante do exposto, o presente estudo teve como objetivo preparar e analisar a composição fitoquímica e a ação antibacteriana dos extratos hidroetanólicos de canela (EHC) e romã (EHR) isolados e associados frente culturas planctônicas e biofilmes de cepas padrão e clínicas de Acinetobacter baumannii e Pseudomonas aeruginosa, além disso, analisar a ação citotóxica dos extratos em queratinócitos humanos (HaCat). Para isso, os EHC e EHR foram preparados e quantificado o teor de sólidos solúveis. Posteriormente, foi quantificado o teor de flavonoides e fenóis totais, análise antioxidante por meio da redução do radical 2,2'-difenil-1-picrilhidrazila (DPPH), e a fitoquímica por cromatografia líquida (HPLC). Em relação a ação antibacteriana dos extratos, foi aplicado o teste de microdiluição em caldo (CLSI ­ M7-A9) e a ação sinérgica realizada por meio do ensaio de checkerboard. As concentrações mais efetivas foram analisadas sobre biofilmes em formação (prevenção) e biofilmes formados (tratamento de 24 h), e quantificada a viabilidade por meio do teste colorimétrico MTT. Para avaliar a citotoxidade, os tratamentos foram aplicados sobre cultura celular de HaCat por 24 h e analisados por meio do teste colorimétrico MTT. A análise estatística foi realizada com 5% de significância (p<0.05), analisados pelo método ANOVA complementado pelo Teste de Tukey. Os resultados demonstraram que os EHC e EHR possuem ação antioxidante e presença de fitocompostos. Os extratos apresentaram ação antibacteriana para todas as cepas avaliadas, quando os mesmos foram associados, obteve-se concentrações sinérgicas para as cepas clínicas de A. baumannii. Em relação a ação antibiofilme, o EHC inibiu a formação em 95% e EHR em 96% do biofilme de #Ab 1, enquanto a cepa #Pa 2 teve 92% e 93% de inibição quando em contato com EHC e EHR, respectivamente. Após tratamento de 24 h em biofilmes formados, as reduções da viabilidade foram de 72% para as cepas #Ab 2 e #Ab 3 quando em contato com o EHC, já EHR inibiu em 83% a viabilidade da cepa #Ab ATCC. Para P. aeruginosa (#Pa 2), as reduções da viabilidade foram de 84% e 88,5% quando tratados com EHC e EHR, respectivamente. A avaliação da citotoxicidade em HaCat demonstrou que após tratamentos com diferentes concentrações dos extratos a viabilidade celular se manteve acima de 70% em todos os grupos. Diante disso, conclui-se que os EHC e EHR apresentam importante ação antioxidante e antibacteriana, tanto em culturas planctônicas quanto em biofilmes, e não apresentaram efeitos citotóxicos na faixa de concentração testada. (AU)

Bacterial resistance has progressively increased in the world, thus, there is a need for new treatment options. Phytotherapy has gained notoriety for fighting infections, mainly those caused by bacteria resistant to available antibacterials. In view of the above, the present study aimed to prepare and analyze the phytochemical composition and antimicrobial action of hydroethanolic extracts of cinnamon (EHC) and pomegranate (EHR) isolated and associated against planktonic cultures and biofilms of standard and clinical strains of Acinetobacter baumannii and Pseudomonas aeruginosa, in addition, analyze the cytotoxic action of the extracts on human keratinocytes (HaCat). For this, the EHC and EHR were prepared and the soluble solids content was quantified. Subsequently, the content of flavonoids and total phenols, antioxidant analysis through the reduction of the radical 2,2'-diphenyl1-picrylhydrazyl (DPPH), and phytochemistry by liquid chromatography (HPLC) were quantified. Regarding the antimicrobial action of the extracts, the broth microdilution test (CLSI ­ M7-A9) was applied and the synergistic action was performed through the checkerboard test. The most effective concentrations were analyzed on forming biofilms (prevention) and formed biofilms (24 h treatment), and viability was quantified using the MTT colorimetric test. To evaluate the cytotoxicity, the treatments were applied on HaCat cell culture for 24 h and analyzed using the MTT colorimetric test. Statistical analysis was performed with 5% significance (p<0.05), analyzed by the ANOVA method complemented by the Tukey test. The results showed that the EHC and EHR have antioxidant action and presence of phytocompounds. The extracts showed antibacterial action for all evaluated strains, when they were associated, synergistic concentrations were obtained for the clinical strains of A. baumannii. Regarding the antibiofilm action, EHC inhibited formation by 95% and EHR by 96% of the #Ab 1 biofilm, while the #Pa 2 strain had 92% and 93% inhibition when in contact with EHC and EHR, respectively. After 24 h treatment in formed biofilms, viability reductions were 72% for strains #Ab 2 and #Ab 3 when in contact with EHC, whereas EHR inhibited the viability of strain #Ab ATCC by 83%. For P. aeruginosa (#Pa 2), viability reductions were 84% and 88.5% when treated with EHC and EHR, respectively. The evaluation of cytotoxicity in HaCat showed that after treatments with different concentrations of extracts, cell viability remained above 70% in all groups. Therefore, it is concluded that EHC and EHR have important antioxidant and antibacterial action, both in planktonic cultures and in biofilms, and did not show cytotoxic effects in the tested concentration range. (AU)

Molecular analysis of the prevalence of Acinetobacter baumannii in hospitals and the surrounding environments: a cross-sectional study

Acinetobacter baumannii is widely recognized in clinical environments due to its infectious capacity, antimicrobial adaptability, and lethality. Analyzing the prevalence of this agent in intra- and extra-hospital environments may reveal target indicators for appropriate management interventions. In this observational cross-sectional study, we evaluated the prevalence of A. baumannii within hospitals with intensive care units and in their external surroundings in a macro-health region of Brazil. Samples of Columba livia (pigeon) droppings from the external environment of four hospitals (n = 40), from floor surfaces (n = 20), and door handles (n = 20) of different hospital wards were collected based on random sampling, all of which were evaluated for the presence of A. baumannii using polymerase chain reactions (PCR). The sensitivity and specificity of the technique was verified after the collected samples were contaminated with clinical samples positive for A. baumannii. We detected a significantly higher A. baumannii prevalence (87.50%, CI = 71.29­100.00) in samples collected within the hospital environment compared with those obtained from the external environment (12.50%, CI = 0.00­28. 71) (p = 0.003). In addition, samples collected from floor surfaces contained bacterial densities (181.3 ± 11.58) that exceeded those in environmental (93.32 ± 1.56) and door handle (142.70 ± 17.14) samples by 94% and 78.71%, respectively. The findings of this study will enhance our understanding of the spatial distribution of A. baumannii and additionally, validate the efficiency of PCR for diagnosis of this infectious agent.

Genes involucrados con resistencia antimicrobiana en hospitales del Ecuador / Genes involved with antimicrobial resistance in Ecuadorian hospitals

INTRODUCCIÓN. La resistencia a los antimicrobianos es un problema de salud pública actual asociado con alta mortalidad, hospitalización prolongada, alternativas terapéuticas reducidas, mayores costos económicos y la posibilidad de brotes hospitalarios. OBJETIVO. Describir los principales genes involucrados con resistencia antimicrobiana en hospitales del Ecuador. MATERIALES Y MÉTODOS. Se realizó una descripción retrospectiva no experimental, de artículos indexados relacionados con resistencia antimicrobiana en hospitales del Ecuador, con evidencia desde el año 2009 al 2022. La revisión de bibliografías se llevó a cabo en bases de datos como Pubmed, Science Direct y Google Scholar. RESULTADOS. De un grupo original de 77 artículos, se seleccionaron 33 documentos. En Ecuador, varios estudios han descrito los mecanismos moleculares involucrados en la resistencia bacteriana. Sin embargo, en bacterias menos comunes, falta investigación sobre los genes asociados. CONCLUSIONES. Las principales bacterias multirresistentes descritas en Ecuador son Klebsiella pneumoniae, Escherichia coli y Acinetobacter baumanni, las cuales presentan genes involucrados en la producción de carbapenemasas (blaKPC, blaNDM, blaOXA-48). Estas bacterias presentan altos niveles de resistencia a los antibióticos y son objeto de vigilancia epidemiológica por parte del sistema nacional de salud. A nivel local, otras bacterias presentan mecanismos de resistencia a los carbapenémicos (Pseudomonas aeruginosa, Enterobacter sp., Serratia marcescens, Citrobacter sp.), pero no existen descripciones detalladas del genotipo, sus características microbiológicas o la clínica del paciente. El conocimiento de las tasas de resistencia a los antimicrobianos en los diferentes hospitales, la implementación de un plan de administración de antibióticos, el uso correcto de los equipos de protección personal, el aislamiento de las personas con infecciones multirresistentes, así como el trabajo colaborativo entre las diferentes áreas del hospital, son esenciales para reducir la propagación de estos patógenos.

INTRODUCTION. Antimicrobial resistance is a current public health problem associated with high mortality, prolonged hospitalization, reduced therapeutic alternatives, increased economic costs, and the potential for hospital outbreaks. OBJECTIVE. To describe the main genes involved with antimicrobial resistance in hospitals in Ecuador. MATERIALS AND METHODS. A retrospective non-experimental description of indexed articles related to antimicrobial resistance in hospitals in Ecuador was carried out, with evidence from 2009 to 2022. The review of bibliographies was carried out in databases such as Pubmed, Science Direct and Google Scholar. RESULTS. From an original group of 77 articles, 33 papers were selected. In Ecuador, several studies have described the molecular mechanisms involved in bacterial resistance. However, in less common bacteria, research on the associated genes is lacking. CONCLUSIONS. The main multidrug-resistant bacteria described in Ecuador are Klebsiella pneumoniae, Escherichia coli and Acinetobacter baumanni, which present genes involved in the production of carbapenemases (blaKPC, blaNDM, blaOXA-48). These bacteria present high levels of antibiotic resistance and are subject to epidemiological surveillance by the national health system. Locally, other bacteria present mechanisms of resistance to carbapenemics (Pseudomonas aeruginosa, Enterobacter sp., Serratia marcescens, Citrobacter sp.), but there are no detailed descriptions of the genotype, their microbiological characteristics or the patient's clinic. Knowledge of antimicrobial resistance rates in different hospitals, the implementation of an antibiotic stewardship plan, the correct use of personal protective equipment, the isolation of individuals with multidrug-resistant infections, as well as collaborative work between different areas of the hospital, are essential to reduce the spread of these pathogens.

Mecanismo de resistência da bactéria Acinetobacter Baumannii e suas implicações no controle das infecções hospitalares / Mechanism of resistance of Acinetobacter Baumannii bacteria and its implications in control of hospital infections

O gênero Acinetobacter spp. surgiu como patógeno hospitalar oportunista, com numerosos surtos hospitalares. O gênero Acinetobacter spp. compreende até 31 espécies, entre elas a espécie Acinetobacter baumannii que é responsável por cerca de 80% das infecções, as quais podem se espalhar de forma epidêmica entre os pacientes hospitalizados e gravemente doentes. A espécie A. baumannii pode estar presente no ambiente hospitalar em máquinas de diálise; nos ventiladores mecânicos; nos monitores de pressão arterial; nos sistemas de ventilação; nas fontes de água; na pele e mucosas dos profissionais de saúde e dos doentes; nas preparações medicamentosas e até nos desinfetantes. Uma ampla variedade de objetos de uso do paciente, como cama, travesseiro, aparelho de televisão e de som, tem sido encontrada contaminada com Acinetobacter, podendo servir como reservatórios durante um surto nosocomial. Para manter resistência, a bactéria deve sofrer alteração no seu material genético, o que poderá ocorrer de duas formas: indução de mutação no DNA ou processo de transformação. Os principais mecanismos de resistência são a alteração da permeabilidade, alteração do sítio de ação do antimicrobiano, bomba de efluxo e mecanismo enzimático pela produção de beta-lactmases, sendo que os principais processos ocorrem por meio de conjugação, transformação e transdução.

The genus Acinetobacter spp emerged as an opportunistic hospital pathogen, with numerous hospital outbreaks. The genus Acinetobacter spp. comprises up to 31 species, among them the species Acinetobacter baumannii is responsible for about 80% of infections which can spread epidemically among hospitalized and seriously ill patients. A. baumannii may be present in the hospital environment on dialysis machines; mechanical fans; blood pressure monitors; ventilation systems; in water sources; on the skin and mucous membranes of health professionals and patients; in drug preparations and even disinfectants. A wide variety of objects for use by the patient, such as bed, pillow, television and stereo, have been found contaminated with Acinetobacter and can serve as reservoirs during a nosocomial outbreak. To maintain resistance, the bacterium must undergo changes in its genetic material, which may occur in two ways: mutation induction in DNA or transformation process. The main resistance mechanisms are the change in permeability, alteration of the antimicrobial action site, efflux pump and enzymatic mechanism by the production of ß-lactmases, and the main processes occur through conjugation, transformation and transduction.

Secondary bacterial infections in patients with coronavirus disease 2019-associated pneumonia

SUMMARY OBJECTIVE: The vast majority of patients who hospitalized with coronavirus disease 2019 are given empirical antibiotic therapy. However, information on the frequency, microorganism species, and resistance rates of secondary bacterial infections in coronavirus disease 2019 patients are insufficient. We aimed to show the frequency of secondary infections and resistance conditions in patients with coronavirus disease 2019 hospitalized in the intensive care unit. METHODS: The results of tracheal aspirate culture, blood culture, and urine culture obtained from coronavirus disease 2019 patients - at least 2 days after their admission to the intensive care unit - were examined microbiologically. RESULTS: A total of 514 patients hospitalized in intensive care unit were included in our study. Tracheal aspirate, blood, or urine cultures were collected from 369 patients (71.8%). Bacterial reproduction was detected in at least one sample in 171 (33.3%) of all patients. The rate of respiratory tract infection and/or bloodstream infection was found to be 21%. Acinetobacter baumannii, Klebsiella pneumoniae, and Pseudomonas aeruginosa in tracheal aspirate culture; Coagulase-negative staphylococci, K. pneumoniae, and A. baumannii in blood culture; and Escherichia coli, K. pneumoniae, and Enterococcus faecalis in urine culture were the most common microorganisms. A. baumannii was resistant to most antibiotics except colistin and P. aeruginosa strains were resistant to most antibiotics except amikacin, colistin, cefepime, and imipenem. In K. pneumoniae, the highest meropenem sensitivity (73%) was observed; there was a strong resistance to most of the remaining antibiotics. CONCLUSIONS: We think that our study can be useful in choosing empirical antibiotic therapy in the coronavirus disease 2019 pandemic and reducing the mortality that may occur with secondary infection.

Vigilancia epidemiológica de Acinetobacter baumannii multirresistente a nivel hospitalario / Epidemiological surveillance of multidrug-resistant Acinetobacter baumannii at hospital level / Vigilância epidemiológica do Acinetobacter baumannii multirresistente em nível hospitalar

La Acinetobacter baumannii se considera como un agente microbiano de gran importancia clínica debido a la resistencia que ha adquirido a los antimicrobianos, esto trae como consecuencias complicaciones al referir una terapia antibiótica, prolongando la estancia en la hospitalización de los pacientes infectados con esta bacteria, causando un alto grado de mortalidad por su elevada capacidad de proliferación en las diferentes áreas hospitalarias. OBJETIVO. Describir la epidemiología de los brotes causados por Acinetobacter baumannii en Latinoamérica, así como también los mecanismos de Resistencia de este patógeno causando inconvenientes al momento de emplear los diferentes tratamientos terapéuticos. MATERIAL Y METODOS. Es una revisión sistemática bajo la declaración PRISMA de las investigaciones relacionadas al tema. Para la búsqueda de información se emplearon fuentes de datos provenientes de: Scielo, Redalyc, Google académico, se encontraron 43 artículos de los cuales solo 25 fueron válidos para la investigación. RESULTADOS. La resistencia que presenta la Acinetobacter baumannii a los antibióticos se incrementó con el pasar de los años. Este incremento de la resistencia se debe a diversos factores entre los cuales se destacan el desarrollo de ß-lactamasas dirigidas contra los betalactámicos, ya sea de amplio espectro o carbapenemasas; variaciones en las proteínas que forman parte de la membrana externa bacteriana, en las bombas de expulsión, perdida de porinas, modificaciones del lugar (blanco o diana) de acción de los antibióticos y variaciones en la expresión de proteínas fijadoras de penicilina. Esta variabilidad depende en parte de la capacidad de la bacteria para adquirir genes de resistencia, a menudo a través de una transferencia horizontal de genes CONCLUSIONES. La Acinetobacter baumannii se caracteriza por tener múltiples mecanismos de resistencia a antibióticos, lo que ha aumentado las consecuencias nocivas de este potencial patógeno y representa un desafío importante para los pacientes y el personal de salud.

Acinetobacter baumannii is considered as a bacterium of great clinical importance due to the resistance it has acquired to antimicrobials, which has triggered complications when referring an antibiotic therapy, prolonging the stay in the hospital of patients infected with this bacterium, causing a high degree of mortality due to its high proliferation capacity between different hospital areas. OBJETIVE. To describe the most relevant aspects about the epidemiology of the outbreaks caused by Acinetobacter baumannii in Latin America, as well as the different resistance mechanisms that this pathogen has acquired thus causing inconveniences when using the different therapeutic treatments. MATERIALS AND METHODS. A systematic review was carried out, under the PRISMA declaration, for the search of the information were used databases such as: Scielo, Redalyc, Google academic, 43 articles were found of which only 25 were valid for research. RESULTS. The resistance of Acitetobacter baumannii to different antibiotic groups has increased over the years. This increase in resistance is due to several factors among which stand out: ß-lactamases directed against beta-lactams, either broad spectrum or carbapenemases; variations in proteins of the outer membrane, ejection pumps, loss of porins, modifications of the place (target) of action of the antibiotics and alterations in the expression of penicillin-fixing proteins. This ability depends in part on the ability of this bacterium to acquire resistance genes, often through horizontal gene transfer. CONCLUSIONS. A. baumannii has developed multiple antibiotic resistance mechanisms, which increase the harmful consequences of this potential pathogen and represents a major challenge for patients and health personnel.

Acinetobacter baumannii é considerada como uma bactéria de grande importância clínica devido à resistência que adquiriu aos antimicrobianos, o que desencadeou complicações no momento de referir uma terapia antibiótica, prolongando a estadia na hospitalização dos pacientes infectados com esta bactéria, causando um elevado grau de mortalidade devido à sua elevada capacidade de proliferação entre diferentes áreas hospitalares. OBJECTIVO. Descrever os aspectos mais relevantes sobre a epidemiologia dos surtos causados por Acinetobacter baumannii a nível da América Latina, bem como os diferentes mecanismos de resistência que adquiriu este patógeno causando com isto inconvenientes o momento de empregar os diferentes tratamentos terapéuticos. MATERIAL E METODOS. Realizou-se uma revisão sistemática, sob a declaração PRISMA, para a busca da informação empregaram-se bases de dados como: Scielo, Redalyc, Google acadêmico, foram encontrados 43 artigos dos quais apenas 25 foram válidos para a pesquisa. RESULTADOS. A resistência que apresenta Acitetobacter baumannii aos diferentes grupos de antibioticos aumentou com o passar dos anos. Este aumento da resistência deve-se a diversos factores, entre os quais se destacam: ß-lactamases dirigidos contra os beta-lactâmicos, quer de largo espectro quer carbapenemases; variações nas proteínas da membrana externa, as bombas de expulsão, perda de porinas, modificações do local (branco) de acção dos antibioticos e alterações na expressão das proteínas fixadoras de penicilina. Esta capacidade depende em parte da capacidade desta bactéria para adquirir genes de resistência, muitas vezes através da transferência horizontal de genes. CONCLUSOES. Acinetobacter baumannii desenvolveu múltiplos mecanismos de resistência aos antibióticos, o que aumentou as consequências nocivas deste potencial patogênico e representa um desafio importante para os pacientes e o pessoal de saúde.

Infecciones asociadas a la atención sanitaria en el Instituto Nacional de Angiología y Cirugía Vascular / Infections associated with health care at the National Institute of Angiology and Vascular Surgery

Introducción: Las infecciones asociadas a la asistencia sanitaria constituyen un problema de salud. Objetivo: Caracterizar las infecciones asociadas a la asistencia sanitaria en los tres servicios del Instituto Nacional de Angiología y Cirugía Vascular durante 2019. Métodos: Estudio longitudinal de epidemiología clínica en 89 pacientes ingresados en 2019, a los que se les diagnosticó una infección asociada a la asistencia sanitaria. Las variables de estudio fueron: edad, sexo, meses del año, servicio asistencial, enfermedades asociadas, gérmenes más frecuentes y principales localizaciones. Se calcularon las frecuencias absolutas y relativas. Resultados: Se encontró una tasa porcentual acumulada de 6,6 por cada 100 egresos, con predominio del sexo masculino y mayor frecuencia en los pacientes de la quinta década de vida. La herida quirúrgica contribuyó con 43 casos de los 89 reportados, seguida por la bronconeumonía bacteriana con 18. La principal enfermedad asociada fue la diabetes mellitus y los gérmenes más frecuentes aislados resultaron Stafilococus aureus, Pseudomona sp y Acinetobacter bawmani. Conclusiones: La tasa de incidencia de infecciones asociadas a la asistencia sanitaria en el Instituto Nacional de Angiología y Cirugía Vascular durante 2019 no difiere de las presentadas en años anteriores y se corresponden con los reportes internacionales(AU)

Introduction: Health care associated infections are a health problem. Objective: Characterize healthcare associated infections in the three services of the National Institute of Angiology and Vascular Surgery during 2019. Methods: Longitudinal study of clinical epidemiology in 89 patients admitted in 2019, who were diagnosed with an infection associated with health care. The study variables were: age, sex, months of the year, care service, associated diseases, more frequent germs and main locations. Absolute and relative frequencies were calculated. Results: A cumulative percentage rate of 6.6 per 100 discharges was found, with male predominance and higher frequency in patients in the fifth decade of life. The surgical wound was present in 43 of the 89 cases reported, followed by bacterial bronchopneumonie with 18. The main associated disease was diabetes mellitus and the most common isolated germs were Stafilococus aureus, Pseudomonasp and Acinetobacter baumannii. Conclusions: The incidence rate of healthcare associated infections at the National Institute of Angiology and Vascular Surgery during 2019 does not differ from those presented in previous years and corresponds to international reports(AU)

Caracterización molecular de carbapenemasas en bacilos gramnegativos circulantes en hospitales de Paraguay. Primer cuatrimestre 2021 / Molecular characterization of carbapenemases in Gram-negative bacilli circulating in hospitals of Paraguay. First quarter of 2021

La resistencia a los antimicrobianos (RAM), representa un grave problema por el uso indiscriminado de antimicrobianos de amplio espectro. En nuestro país, durante el primer cuatrimestre del año, se observó un aumento inusual en el número de aislamiento de gérmenes multirresistentes, sobre todo de bacilos gramnegativos, los cuales fueron remitidos al laboratorio de referencia con el objetivo de caracterizar los genes de resistencia a los carbapenemes. Estudio observacional y prospectivo de corte transversal en 456 aislamientos de bacilos gramnegativos provenientes de 11 centros colaboradores de la Red Nacional de Vigilancia de la RAM, remitidos al Laboratorio Central de Salud Pública entre enero y abril de 2021, para la detección molecular (reacción en cadena de la polimerasa múltiple) de los genes de resistencia enzimática bla OXA-51, bla OXA-23, bla OXA-24, bla OXA-48, bla OXA-58, bla NDM, bla KPC, bla IMP, bla VIM. Trescientos sesenta correspondieron a bacilos gramnegativos no fermentadores: 346 Acinetobacter baumannii y 14 Pseudomonas aeruginosa; 96 fueron miembros de Enterobacterales, siendo prevalente Klebsiella pneumoniae (81). Todos los aislamientos de Acinetobacter baumannii resultaron ser productores de carbapenemasas: OXA-23 (94%), NDM (4%), NMD+OXA-58 (2%); en Pseudomonas aeruginosa, 7 de los 14 aislamientos (50%) fueron portadores de metalobetalactamasa del genotipo NDM (100%). Los genotipos NDM (92%) y KPC (8%) fueron confirmados en Enterobacterales. La resistencia plasmídica a carbapenemes es endémica en nuestro país, siendo prevalentes los genotipos OXA-23 en Acinetobacter baumannii y NDM en Pseudomonas aeruginosa y Enterobacterales

Antimicrobial resistance (AMR) represents a serious problem due to the indiscriminate use of broad-spectrum antimicrobials. During the first quarter of the year, an unusual increase in the number of isolation multi-resistant germs, especially gram-negative bacilli was observed, specially of Gram-negative bacilli which were referred to the reference laboratory in order to characterize the carbapenems resistance genes. Observational and prospective cross-sectional study in 456 isolates of Gram-negative bacilli from 11 collaborating centers of the National AMR Surveillance Network, referred to the Central Public Health Laboratory (LCSP) between January and April 2021, for molecular detection (multiple polymerase chain reaction) targeting the enzymatic resistance genes: bla OXA-51, bla OXA-23, bla OXA-24, bla OXA-48, bla OXA-58, bla NDM, bla KPC, bla IMP, bla VIM. Of the 456 isolates studied, 360 corresponded to non-fermenting Gram-negative bacilli, of which 346 were confirmed as Acinetobacter baumannii and 14 Pseudomonas aeruginosa; 96 were Enterobacterales, being Klebsiella pneumoniae (81) the most prevalent. All isolates of Acinetobacter baumannii carried genes encoding carbapenemases, being the OXA-23 (94%) followed by NDM (4%) and NDM +OXA-58 (2%). In Pseudomonas aeruginosa strains, 7 of the 14 isolates (50%) were carriers of NDM metallobetalactamase (100%). No carbapenemase gene was detected in the remaining 7. In all Enterobacterales strains, the presence of carbapenemases of the NDM (92%) and KPC (8%) genotypes were confirmed. Plasmid resistance to carbapenems is endemic in our country, being the OXA-23 genotypes prevalent in Acinetobacter baumannii and NDM in Pseudomonas aeruginosa and Enterobacterales

Caracterización de bacilos gramnegativos multi-resistentes, aislados en pacientes hospitalizados en instituciones de salud de Barranquilla (Colombia) / Characterization of multiresistant gram-negative bacilli, isolated in patients hospitalized in health institutions in Barranquilla (Colombia)

Resumen Introducción: La resistencia a carbapenémicos en bacilos gramnegativos es un problema de salud pública mundial, debido a que se asocia con altas tasas de mortalidad, aumento en los niveles de resistencia a otros antimicrobianos, elevación en el potencial de diseminación e incremento en los costos de atención en salud. Objetivo: Caracterizar bacilos gramnegativos multirresistentes, aislados en pacientes hospitalizados en instituciones de salud de Barranquilla (Colombia). Material y Métodos: Estudio descriptivo acerca de la caracterización fenotípica y genotípica de la resistencia bacteriana en las infecciones asociadas a la atención en salud, mediada por carbapenemasas en aislados bacterianos enviados por los laboratorios pertenecientes a la red de laboratorios del Departamento del Atlántico. Resultados: La KPC fue la carbapenemasa más frecuente en las Enterobacterales (27,6%), predominando en Klebsiella pneumoniae (13,1%) sola y asociada a otras carbapenemasas. En Pseudomonas aeruginosa predominó la carbapenemasa VIM (32,8%) y la OXA en Acinetobacter baumannii (17,1%). Conclusión: Se encontró una amplia distribución de cepas multi-resistentes productoras de carbapenemasas en instituciones de salud de Barranquilla, las cuales expresaron los siguientes mecanismos de resistencia: KPC, VIM, NDM, OXA.

Abstract Background: The emergence of carbapenem resistant gramnegative bacilli has become a problem of public health worldwide, because it is associated with high mortality rates, increased levels of resistance to other antimicrobials, increased potential for dissemination transition and increase in health care costs. Aim: To characterize multiresistant gram-negative bacilli, isolated in patients hospitalized in health institutions of Barranquilla (Colombia). Methods: A descriptive study was conducted on the phenotypic and genotypic characterization of bacterial resistance in infections associated with health care, mediated by carbapenemases in bacterial isolates sent by laboratories belonging to the laboratory network of the Department of Atlántico. Results: KPC was the most frequent carbapenemase in Enterobacterales (27.6%), predominantly in Klebsiella pneumoniae (13.1%) alone and associated with other carbapenemases. In Pseudomonas aeruginosa, VIM carbapenemase (32.8%) predominated and OXA in Acinetobacter baumannii (17.1%). Conclusion: A wide distribution of multi-resistant strains producing carbapenemases in Atlantic health institutions was found, which expressed the following resistance mechanisms: KPC, VIM, NDM, OXA.

Efeitos do fotoenticine, azul de metileno e farnesol na terapia fotodinâmica antimicrobiana para controle de Acinetobacter baumannii / Effects of fotoenticine, methylene blue and farnesol on antimicrobial photodynamic therapy for control of Acinetobacter baumannii

A terapia fotodinâmica antimicrobiana (TFDa) tem sido considerada uma alternativa para o tratamento de infecções cutâneas causadas por Acinetobacter baumannii. Entretanto, é necessária a busca por fotossensibilizadores ou compostos que potencializem seus efeitos. Os objetivos desse estudo foram testar uma nova Clorina e-6 (Fotoenticine FTC) como fotossensibilizador para TFDa sobre A. baumannii, e o Farnesol como potencializador dessa terapia. Além disso, os efeitos do FTC foram comparados ao Azul de Metileno (AM), um fotossensibilizador já aprovado para uso clínico. Para isso, foram empregados os seguintes métodos: 1) Teste de concentração inibitória mínima (CIM) para estabelecer a concentração do Farnesol a ser utilizada no estudo, 2) TFDa em culturas planctônicas com ou sem tratamento prévio com Farnesol, 3) Teste de permeabilidade da membrana celular de A. baumannii e análise por microscopia confocal para avaliar a internalização dos fotossensibilizadores, 4) TFDa em biofilmes para determinar a contagem de UFC/mL de A. baumannii e a viabilidade celular por fluorescência, 5) Ensaios in vivo para avaliar os efeitos da TFDa sobre lesões de queimadura infectadas por A. baumannii em Galleria mellonella. Como resultados, observou-se no teste de CIM que o Farnesol não teve efeito antimicrobiano sobre A. baumannii. A TFDa com AM e FTC reduziu, respectivamente, 4 e 2 log (UFC/mL) de A. baumannii em crescimento planctônico. Ambos os fotossensibilizadores foram capazes de penetrar nas células bacterianas, porém o Farnesol não aumentou a permeabilidade celular. A TFDa com AM reduziu 4 log (UFC/mL) de A. baumannii em biofilmes, já a TFDa com FTC não apresentou efeito sobre a contagem de UFC/mL. A aplicação da TFDa com FTC não teve efeito sobre as lesões de queimadura em G. mellonella, entretanto a TFDa com AM aumentou a sobrevida das larvas em 35%. Concluiu-se que a TFDa com FTC teve ação antimicrobiana apenas em culturas planctônicas de A. baumannii e a ação do Farnesol associada a TFDa foi cepa dependente. Dentro dos parâmetros testados nesse estudo, a atividade antimicrobiana da TFDa com FTC foi inferior ao AM nos ensaios in vitro e in vivo

Antimicrobial photodynamic therapy (aPDT) has been an alternative for the treatment of skin infections caused by Acinetobacter baumannii. However, it is necessary to search for photosensitizers or compounds that enhance their effects. The objectives of this study were to test a new Chlorine e-6 (Fotoenticine FTC) as a photosensitizer for aPDT on A. baumannii, and Farnesol as an enhancer for this therapy. In addition the effects of FTC were compared to Methylene Blue (MB), a photosensitizer already approved for clinical use. For this, the following methods were used: 1) Minimum inhibitory concentration test (MIC) to establish the concentration of Farnesol to be used in the study, 2) aPDT in planktonic cultures with or without previous treatment with Farnesol, 3) Permeability test of the cell membrane of A. baumannii and analysis by confocal microscopy to assess the internalization of photosensitizers, 4) aPDT in biofilms to determine the CFU/mL count of A. baumannii and cell viability by fluorescence, 5) In vivo assays to evaluate the effects of aPDT on burn injuries infected by A. baumannii in Galleria mellonella. As a result, it was observed in the MIC test that Farnesol had no antimicrobial effect on A. baumannii. aPDT with MB and FTC reduced, respectively, 4 and 2 log (CFU/mL) of A. baumannii in planktonic growth. Both photosensitizers were able to penetrate bacterial cells, however Farnesol did not increase cell permeability. aPDT with MB reduced 4 log (CFU/mL) of A. baumannii in biofilms, whereas aPDT with FTC had no effect on the CFU/mL count. The application of aPDT with FTC had no effect on burn injuries in G. mellonella, however aPDT with MB increased the larvae survival by 35%. It was concluded that aPDT with FTC had antimicrobial action only in planktonic cultures of A. baumannii and the action of Farnesol associated with PDT was a dependent strain. Within the parameters tested in this study, the antimicrobial activity of aPDT with FTC was lower than MB in in vitro and in vivo assays

Molecular epidemiology of carbapenem-resistant Acinetobacter baumannii from southern Brazil / Epidemiologia molecular de Acinetobacter baumannii resistente aos carbapenêmicos provenientes do sul do Brasil / Epidemiología molecular de Acinetobacter baumannii resistente a carbapenem del sur de Brasil

Background and Objectives: carbapenem resistance in Acinetobacter baumannii has reached extremely high levels worldwide, and class D OXA-type carbapenemases are the main associated mechanism. This study aimed to assess the phenotypic and molecular profile of clinical carbapenem-resistant A. baumannii (CRAb) isolates from a southern Brazilian border region. Methods: A. baumannii species was identified by the presence of the blaOXA-51 gene, and the susceptibility profile was determined by broth microdilution. The main carbapenemases were investigated by PCR and the molecular typing was performed by PFGE. Results: during the study, a total of 36 CRAb were recovered, of which 85.7% were from respiratory tract samples from ICU patients. High level resistance to were found in contrast to 100% of susceptibility for polymyxin B. The blaOXA-23 gene was present in 34 isolates and was the only one detected other than blaOXA-51. Molecular typing revealed the presence of four clonal strains, two of them endemic during the period of the study. Conclusion: to the best of our knowledge, our study brings the first data about resistance profile in Acinetobacter in the western border of southern Brazil and make aware of endemic clones of CRAb-producing-OXA-23 in this region of state, contributing for the construction of the national epidemiologic scenario of CRAb.(AU)

Justificativa e Objetivos: a resistência aos carbapenêmicos em Acinetobacter baumannii atingiu níveis extremamente altos em todo o mundo, e as carbapenemases do tipo OXA classe D são o principal mecanismo associado. O objetivo deste estudo foi avaliar o perfil fenotípico e molecular de isolados clínicos de A. baumannii resistentes aos carbapenêmicos (CRAb) de uma região de fronteira do sul do Brasil. Métodos: a espécie A. baumannii foi identificada através da presença do gene blaOXA-51, e o perfil de sensibilidade foi determinado por microdiluição em caldo. As principais carbapenemases foram investigadas por PCR, e a tipagem dos isolados de CRAb foi realizada por PFGE. Resultados: durante o período do estudo, 36 CRAb foram recuperados, dos quais 85,7% foram provenientes de amostras do trato respiratório de pacientes de UTI. Uma elevada resistência a aminoglicosídeos e fluoroquinolonas foi encontrada em contraste com 100% de sensibilidade a polimixina B. O gene blaOXA-23 foi encontrado em 34 isolados e foi o único detectado além do blaOXA-51. A tipagem molecular revelou a presença de quatro linhagens clonais, duas delas endêmicas ao longo do período do estudo. Conclusão: nosso estudo traz os primeiros dados sobre o perfil de resistência em Acinetobacter na fronteira oeste do sul do Brasil e alerta para a presença de clones endêmicos de CRAb produtores de OXA-23 nessa região, contribuindo para a construção do cenário epidemiológico nacional de CRAb.(AU)

Justificación y Objetivos: la resistencia a carbapenémicos en Acinetobacter baumannii ha alcanzado niveles extremadamente altos en todo el mundo y las carbapenemases OXA de clase D son el principal mecanismo asociado. El objetivo de este estudio fue evaluar el perfil fenotípico y molecular de los aislados clínicos de A. baumannii resistentes a carbapenémicos (CRAb) de una región fronteriza en el sur de Brasil. Métodos: la especie A. baumannii se identificó a través de la presencia del gen blaOXA-51 y el perfil de sensibilidad se determinó por microdilución en caldo. Las principales carbapenemasas fueron investigadas por PCR y la tipificación se hizo con PFGE. Resultados: durante el período de estudio, se recuperaron 36 CRAb, 85,7% de muestras del tracto respiratorio de pacientes de la UCI. Se encontró una alta resistencia a los aminoglucósidos y las fluoroquinolonas en contraste con 100% de sensibilidad a polimixina B. El gen blaOXA-23 se encontró en 34 aislamientos y fue el único detectado además de blaOXA-51. La tipificación molecular reveló la presencia de cuatro cepas clonales, dos de ellas endémicas durante el período de estudio. Conclusiones: hasta donde sabemos, nuestro estudio trae los primeros datos sobre el perfil de resistencia en Acinetobacter en la frontera oeste del sur de Brasil y reconoce los clones endémicos de CRAb productores de OXA.(AU)

Perfil de suscetibilidade a antimicrobianos de cepas de Acinetobacter baumannii e Pseudomonas aeruginosa isoladas em amostras de lavado traqueal / Antimicrobial resistance profile of Acinetobacter baumannii and Pseudomonas aeruginosa strains isolated from tracheal lavage samples

Objetivo: Avaliar a prevalência e o perfil de suscetibilidade aos antimicrobianos das cepas de Acinetobacter baumannii e Pseudomonas aeruginosa isoladas de amostras de lavado traqueal. Métodos: Trata-se de um estudo retrospectivo, transversal, descritivo, no qual foram coletados resultados de cultura de lavado traqueal de pacientes com PAV, internados em uma UTI adulta de um hospital público da cidade de Juiz de Fora, MG. Os dados foram coletados nos registros eletrônicos do Serviço de Controle de Infecção Hospitalar, referentes ao período de janeiro a dezembro de 2018. Resultados: Foram analisadas 469 amostras de lavado traqueal de pacientes adultos internados na UTI, sendo consideradas culturas positivas, aquelas com contagem de colônias ≥106UFC/ mL, totalizando 242 (51,52%) das amostras de lavado traqueal positivas, sendo que, destas, 230 foram monomicrobianas e 12 com dois micro-organismos. Foram isoladas 59 (24,89%) cepas de Acinetobacter baumannii e 45 (18,98%) cepas de Pseudomonas aeruginosa. De acordo com os critérios do CLSI 2018, 100% das cepas de A. baumannii se mostraram resistentes a meropenem, cefepime, ceftriaxona, ceftazidima e piperaci- lina-tazobactam. Conclusão: A. baumannii e Pseudomonas aeruginosa são agentes importantes de PAV, sendo que A. baumannii foi o patógeno mais comumente associado e apresentou multirresistência aos fármacos testados.

Objective: The objective of this study is to evaluate the prevalence and antimicrobial susceptibility profile of strains of A. baumannii and P. aeruginosa isolated from tracheal lavage. Methods: This is a retrospective, cross-sectional, descriptive study where tracheal lavage culture results were collected from patients with VAP admitted to an adult ICU at a public hospital in the city of Juiz de Fora. Data were collected through the records of the Hospital Infection Control Service for the period from January to December 2018. Results: 469 tracheal lavage samples from adult patients admitted to the ICU were analyzed. Positive cultures were considered if ≥106CFU / mL, totaling 242 (51.52%) of the tracheal lavage samples were positive; 55 (24.89%) strains of A. baumannii and 45 (18.98%) strains of P. aeruginosa were isolated. According to the CLSI 2018 criteria, A. Baumannii presented 100% of the strains resistant to meropenem, cefepime, ceftriaxone, ceftazidime and piperacillin-tazobactam. Conclusion: A. baumannii and P. aeruginosa are important agents of PAV. Furthermore, A. baumannii was the most commonly associated pathogen and presented multiresistance to the drugs tested, being considered as a public health issue.

Molecular epidemiology and drug resistance of Acinetobacter baumannii isolated from a regional hospital in the Brazilian Amazon region

Abstract INTRODUCTION: In this study, we report a clonal dissemination of carbapenem resistant Acinetobacter baumannii isolates due to the acquisition of blaOXA-23 in a regional hospital located in Brazilian Amazon Region. METHODS: The isolates were identified by MALDI-TOF and the carbapenemase-encoding genes were detected by multiplex-PCR. The genetic similarity was investigated by pulsed-field gel electrophoresis (PFGE). RESULTS: Only 10 (55.6%) isolates harbored the gene bla OXA-23. PFGE analysis revealed that these isolates belong to a single clone. CONCLUSIONS: This dissemination strategy indicates the need for surveillance, adoption of control procedures defined in guidelines, and the careful administration of antimicrobials should be reinforced.

Expression analysis of drug-resistant gene (blaOXA-51) in carbapenemases producing Acinetobacter baumannii treated with imipenem/sulbactam combination

Drug-resistant Acinetobacter baumannii is a frightening reality. The aim of this study is to examine the expression profiles of blaOXA-51 gene in carbapenemases producing A. baumannii treated with imipenem/sulbactam combination. Carbapenemases producing A. baumannii was identified among clinical isolates of A. baumannii obtained from patients at Shahid Rajaee hospital, Gachsaran, Iran, from January to June 2018. Synergism testing of imipenem/sulbactam on carbapenemases producing A. baumannii was carried out by broth microdilution method. Eventually, the expression of blaOXA-51 gene was carried out to investigate the inhibitory properties of imipenem/sulbactam combination against carbapenemases producing A. baumannii using quantitative real time RT-PCR. Among A. baumannii isolates, 24% were carbapenemases producing A. baumannii. Imipenem/sulbactam combination revealed synergistic and partial synergistic effect for all tested isolates (FIC= 0.313-0.75). Finally, imipenem/sulbactam combination displayed significant down-regulation of blaOXA-51 gene in carbapenemases producing A. baumannii. Imipenem synergizes with sulbactam against carbapenemases producing A. baumannii by targeting of the blaOXA-51 gene.

Demanda de culturas microbiológicas e prevalência de microrganismos em um hospital universitário de Pernambuco / Demand for microbiological cultures and prevalence of microorganisms in a university hospital of Pernambuco / Demanda de culturas microbiológicas y prevalencia de microrganismos en un hospital universitario de Pernambuco

Objetivo: verificar a demanda de hemoculturas, aspirados traqueais e uroculturas realizadas no HU-UNIVASF/ EBSERH e a prevalência dos microrganismos identificados no período de janeiro a junho de 2016. Métodos: estudo retrospectivo documental com abordagem quantitativa. Resultados: o setor de microbiologia realizou 488 hemoculturas, 427 uroculturas e 197 aspirados traqueais. A positividade de hemoculturas mostrou-se entre 10,9 à 25,7%, e o percentual de contaminações variou de 6,8 à 14,0%. Os microrganismos mais prevalência nas hemoculturas foram Staphylococcus epidermidis (23,7%), Staphylococcus aureus (19,3%) e Klebisiella pneumoniae (9,6%). Nas uroculturas foram Klebisiella pneumoniae (23,1%), Candida sp. (13,5%) e Escherichia coli (12,5%). Nos aspirados traqueais foram Acinetobacter baumannii (29,2%), Pseudomonas aeruginosa (26,6%) e Staphylococcus aureus (16,2%). Conclusão: a cultura mais solicitada foi hemocultura. A bactéria mais prevalente nas hemoculturas foi Staphylococcus epidermidis, nos aspirados traqueais Acinetobacter baumannii e nas uroculturas Klebisiella pneumoniae

Objective: the study's purpose has been to verify the demand for blood cultures, tracheal aspirates and urine cultures performed at a University Hospital from the Universidade Federal do Vale do São Francisco (HU-UNIVASF/EBSERH), as well as the predominance of microorganisms identified over the period from January to June 2016. Methods: it is a retrospective documentary study with a quantitative approach. Results: the microbiology sector carried out 488 blood cultures, 427 urine cultures and 197 tracheal aspirates. The positivity of blood cultures was between 10.9 and 25.7%, and the percentage of contaminations ranged from 6.8 to 14.0%. The most prevalent microorganisms in blood cultures were Staphylococcus epidermidis (23.7%), Staphylococcus aureus (19.3%) and Klebsiella pneumoniae (9.6%). In urine cultures were Klebsiella pneumoniae (23.1%), Candida sp. (13.5%) and Escherichia coli (12.5%). In tracheal aspirates were Acinetobacter baumannii (29.2%), Pseudomonas aeruginosa (26.6%) and Staphylococcus aureus (16.2%). Conclusion: the most requested culture was blood culture. The most prevalent bacterium in blood cultures was Staphylococcus epidermidis, in tracheal aspirates was Acinetobacter baumannii, and in urine cultures was Klebsiella pneumoniae

Objetivo: el propósito del trabajo es verificar la demanda de hemocultivos, aspirados traqueales y urocultivos realizados en el Hospital Universitário de la Universidade Federal do Vale do São Francisco (HU-UNIVASF/ EBSERH) y la prevalencia de los microorganismos identificados en el período de enero a junio de 2016. Métodos: este trabajo es un estudio retrospectivo documental con abordaje cuantitativo. Resultados: el sector de microbiología realizó 488 hemocultivos, 427 urocultivos y 197 aspirados traqueales. La positividad de hemocultivos se mostró entre el 10,9 al 25,7%, y el porcentaje de contaminaciones varía de 6,8 a 14,0%. Los microorganismos más prevalentes en los hemocultivos fueron Staphylococcus epidermidis (23,7%), Staphylococcus aureus (19,3%) y Klebsiella pneumoniae (9,6%). En los urocultivos fueron Klebisiella pneumoniae (23,1%), Candida sp. (13,5%) y Escherichia coli (12,5%). En los aspirados traqueales fueron Acinetobacter baumannii (29,2%), Pseudomonas aeruginosa (26,6%) y Staphylococcus aureus (16,2%). Conclusión: la cultura más solicitada fue hemocultivo. La bacteria más prevalente en los hemocultivos fue Staphylococcus epidermidis, en los aspirados traqueales, Acinetobacter baumannii y en los urocultivos, Klebisiella pneumoniae

Role of aminoglycoside-modifying enzymes and 16S rRNA methylase (ArmA) in resistance of Acinetobacter baumannii clinical isolates against aminoglycosides

Abstract INTRODUCTION: This study aimed to determine the role of genes encoding aminoglycoside-modifying enzymes (AMEs) and 16S rRNA methylase (ArmA) in Acinetobacter baumannii clinical isolates. METHODS: We collected 100 clinical isolates of A. baumannii and identified and confirmed them using microbiological tests and assessment of the OXA-51 gene. Antibiotic susceptibility testing was carried out using disk agar diffusion and micro-broth dilution methods. The presence of AME genes and ArmA was detected by PCR and multiplex PCR. RESULTS: The most and least effective antibiotics in this study were netilmicin and ciprofloxacin with 68% and 100% resistance rates, respectively. According to the minimum inhibitory concentration test, 94% of the isolates were resistant to gentamicin, tobramycin, and streptomycin, while the highest susceptibility (20%) was observed against netilmicin. The proportion of strains harboring the aminoglycoside resistance genes was as follows: APH(3′)-VIa (aphA6) (77%), ANT(2")-Ia (aadB) (73%), ANT(3")-Ia (aadA1) (33%), AAC(6′)-Ib (aacA4) (33%), ArmA (22%), and AAC(3)-IIa (aacC2) (19%). Among the 22 gene profiles detected in this study, the most prevalent profiles included APH(3′)-VIa + ANT(2")-Ia (39 isolates, 100% of which were kanamycin-resistant), and AAC(3)-IIa + AAC(6′)-Ib + ANT(3")-Ia + APH(3′)-VIa + ANT(2")-Ia (14 isolates, all of which were resistant to gentamicin, kanamycin, and streptomycin). CONCLUSIONS: High minimum inhibitory concentration of aminoglycosides in isolates with the simultaneous presence of AME- and ArmA-encoding genes indicated the importance of these genes in resistance to aminoglycosides. However, control of their spread could be effective in the treatment of infections caused by A. baumannii.

In vitro effectiveness of an aqueous extract of neem (azadirachta indicaa. juss) leaves on bacteria causing healthcare associated infection in Valledupar / Efectividad in vitrodel extracto de hojas de neem (azadirachta indicaa. juss) sobre bacterias causantes de infecciónes asociadas a la atención sanitaria en Valledupar

Background: Globally,the need to address strategies for preventing infections associated with health care has increased worldwide. In the city of Valledupar, Colombia, reports of bacteria resistant to chemical or enzymatic biocides in hospital environments and surfaces are increasingly frequent, evidencing the importance of conducting studies aimed at identifying alternative active ingredients for disinfectant products. Objective: Evaluate the in vitro effectiveness of Neem leaves extract over bacteria strains isolated from different areas and surfaces of a health institution in Valledupar, compared to disinfectants for hospital use, an enzymatic detergent, and a commercial chemical disinfectant. Methods: Biocidal activities on bacteria isolated from hospital surfaces, such as Acinetobacter baumanni, Bacillus subtilis, Enterobacter aerogenes, Staphylococcus aureus, Staphylococcus epidermidis, Micrococcus sp, and Stenotrophomonas maltophilia were analyzed. The Neem leaves extract was evaluated at concentrations of 3, 4, and 5 % for each bacterium during 15-minute contact time, incubated at 37 °C for 18 hours. We compared two antimicrobial chemicals, a disinfectant (based on formaldehyde, cetrimide, and glutaraldehyde), and an enzymatic detergent (based on protease, lipase, and amylase). Results: The aqueous Neem extract did not show significant differences with the other treatments with 99.48 to 100% inhibition against bacteria of the species Acinetobacter baumanni, Enterobacter aerogenes, Staphylococcus aureus,and Micrococcus sp.; Bacillus subtilis, and Stenotrophomonas maltophilia strains were the most resistant strains inhibited by enzymatic detergent and disinfectant, respectively. None of the products evaluated were effective against all in vitro strains. Conclusions: These data show Neem's bacteriostatic properties, its potential in in-hospital products and the need to combine different active ingredients in a disinfection plan.

Antecedentes: A nivel mundial ha aumentado la necesidad de abordar estrategias para la prevención de infecciones asociadas a la atención de salud. En la ciudad de Valledupar, Colombia, cada vez son más frecuentes los reportes de bacterias resistentes a biocidas químicos o enzimáticos, en ambientes y superficies hospitalarias, lo cual evidencia la importancia de realizar estudios orientados a la identificación de principios activos alternativos para productos desinfectantes. Objetivo: Evaluar la efectividad in vitrodel extracto de hojas de Neem en cepas de bacterias aisladas en diferentes áreas y superficies de una institución de salud en Valledupar, en comparación con desinfectantes de uso hospitalario, un detergente enzimático y un desinfectante químico comercial. Métodos: Se analizó la actividad biocida sobre las bacterias aisladas de superficies hospitalarias Acinetobacter baumanni, Bacillus subtilis, Enterobacter aerogenes, Staphylococcus aureus, Staphylococcus epidermidis, Micrococcus sp, y Stenotrophomonas maltophilia. El extracto de hojas de Neem se evaluó a concentraciones de 3, 4 y 5% para cada bacteria durante un tiempo de contacto de 15 minutos, incubados a 37 ° C durante 18 horas. Se comparó dos productos químicos antimicrobianos, un desinfectante (a base de formaldehído, cetrimide y glutaraldehído), y un detergente enzimático (a base de Proteasa, Lipasa y amilasa). Resultados: El extracto acuoso de Neem no presentó diferencias significativas con los demás tratamientos con inhibición del 99,48 al 100%, sobre bacterias de las especies Acinetobacter baumanni, Enterobacter aerogenes, Staphylococcus aureus y Micrococcus sp; las cepas Bacillus subtilisy Stenotrophomonas maltophilia fueron las más resistentes a ser inhibidas por el detergente enzimático y el desinfectante, respectivamente. Ninguno de los productos evaluados fue efectivo contra todas las cepas in vitro. Conclusiones: Estos datos evidencian las propiedades bacteriostáticas del Neem, su potencial en productos de uso intrahospitalario y la necesidad de combinar diferentes principios activos en un plan de desinfección.