Resistencia antibiótica de Escherichia coli y Staphylococcus saprophyticus en la infección urinaria de un hospital público / Antibiotic resistance of Escherichia coli and Staphylococcus saprophyticus in urinary tract infection in a public hospital

La resistencia de antibióticos puede llegar a causar una amplia morbilidad y complicaciones. Objetivo: Determinar el perfil de resistencia antimicrobiana de Escherichia Coli y de Staphylococcus Saprophyticus, en pacientes con infección urinaria hospitalizados en el servicio de Medicina Interna del Hospital Municipal Los Olivos. Métodos: Estudio descriptivo, retrospectivo de corte transversal. Se realizó en el servicio de Medicina Interna del Hospital Municipal los Olivos (HMLO). Participantes: historia clínica de pacientes hospitalizados con infección urinaria en el servicio de Medicina Interna. Intervenciones: Según los criterios de inclusión y exclusión se obtuvieron, 96 historias clínicas (HC) del año 2013. Se utilizó un instrumento de recolección validado. Se realizó el análisis descriptivo con software estadístico STATA versión 25. Resultados: De las 96 HC, la edad promedio fue 55,04 años, los agentes microbianos más frecuentes fueron: la Escherichia coli con 85,3%, Staphylococcus saprophyticus 4.2% y Klebsiella pneumoniae 3,1%. La prevalencia de productores de betalactamasa espectro extendido (BLEE) fue 10,4%. Los antibióticos más resistentes fueron: trimetoprim/sulfametoxazol 89,6%, ampicilina 86%, piperacilina 84,6%, tetraciclina 79,2% y ciprofloxacino 70,8%. Los antibióticos más sensibles fueron: amikacina 100%, imipenem 100%, ertapenem 98%, meropenem 96% y piperacilina/tazobactam 96%. Conclusión: El uropatógeno más frecuente en pacientes con ITU hospitalizados fue la E. coli. Los antibióticos que presentaron resistencia a la E. coli fueron: trimetoprim/sulfametoxazol, ampicilina, piperacilina, tetraciclina y ciprofloxacino, y para el S. Saprophyticus fueron: amoxicilina/ ácido clavulánico, trimetoprim/sulfametoxazol, ceftriaxona y ciprofloxacino(AU)

Resistance to antibiotics may actually cause extensive morbidity and complications. Objective: To determine the antimicrobial resistance profile of Escherichia coli and Staphylococcus saprophyticus, in patients with urinary infection hospitalized in the Internal Medicine service of the Los Olivos Municipal Hospital. Methods: Descriptive, retrospective cross-sectional study. It was carried out in the Internal Medicine service of the Los Olivos Municipal Hospital (HMLO). Participants: clinical history of hospitalized patients with urinary infection in the Internal Medicine service. Interventions: According to the inclusion and exclusion criteria, 96 clinical records (HC) from 2013 were obtained. A validated collection instrument was used. Descriptive analysis was performed with STATA version 25 statistical software. Results: Of the 96 CHs, the average age was 55.04 years, the most frequent microbial agents were: Escherichia Coli with 85.3%, Staphylococcus saprophyticus 4.2% and Klebsiella pneumoniae 3.1%. The prevalence of extended spectrum beta-lactamase producers (ESBL) was 10.4%. The most resistant antibiotics were trimethoprim / sulfamethoxazole 89.6 %, ampicillin 86 %, piperacillin 84.6 %, tetracycline 79.2 % and ciprofloxacin 70.8 %. The most sensitive antibiotics were: amikacin 100%, imipenem 100%, ertapenem 98%, meropenem 96% and piperacillin / tazobactam 96%. Conclusion: The most common uropathogen in hospitalized UTI patients was E. coli. The antibiotics that showed resistance to E. coli were: trimethoprim/sulfamethoxazole, ampicillin, piperacillin, tetracycline, and ciprofloxacin, and for S. saprophyticus they were: amoxicillin/clavulanic acid, trimethoprim / sulfamethoxazole, ceftriaxone and ciprofloxacin(AU)

Fatores relacionados à infecção por Klebsiella pneumoniae em um hospital privado / Factors related to infection by Klebsiella pneumoniae in a private hospital / Factores relacionados con la infección por Klebsiella pneumoniae en un hospital privado

Objective:To identify the prevalence of klebsiella pneumoniae and to analyze the factors related to the infection by this bacterium in a private hospital in northeastern Brazil. Method: descriptive retrospective documentary study, carried out with patients who developed infection in the year 2017 (n: 64). Sociodemographic and infection information was collected. The data was processed in SPSS 20.0. The project was approved by the ethics committee. Results: the most prevalent topographic site was the urinary tract (34; 56.7%). the main risk factor for triggering klebsiella pneumoniae infection was the use of mechanical ventilation, presenting a risk of 43.8% for the appearance of infections by this microorganism. Higher resistance was found for the piperacillin / tazobactam 52 antimicrobial (82.5%). Conclusion: because of the high resistance to antibiotics and the great potential of klebsiella contamination, measures should be taken to minimize the high level of contamination and, especially, the negative prognosis for the patient

Objetivo: Identificar a prevalência de Klebsiella pneumoniae e analisar os fatores relacionados à infecção por essa bactéria em hospital privado do nordeste brasileiro. Método: estudo descritivo retrospectivo documental, realizado com pacientes que desenvolveram infecção no ano de 2017 (n:64). Coletou-se informações sociodemográficas e referentes a infecção. Os dados foram processados no SPSS 20.0. O projeto foi aprovado pelo comitê de ética. Resultados: o sítio topográfico mais prevalente foi o trato urinário (34;56,7%). o principal fator de risco para desencadear infecção por Kebsiella pneumoniae foi a utilização de ventilação mecânica, apresentando risco de 43,8% para o aparecimento de infecções por esse microrganismo. Maior resistência foi encontrada para o antimicrobiano piperacilina/tazobactam 52 (82,5%). Conclusão: pela alta resistência aos antibióticos e o grande potencial de contaminação da klebsiella, medidas devem ser adotadas para minimizar o alto nível de contaminação e, principalmente do prognóstico negativo para paciente

Objetivo: Identificar la prevalencia de klebsiella pneumoniae y analizar los factores relacionados con la infección por esta bacteria en un hospital privado en el noreste de Brasil. Método: estudio descriptivo retrospectivo, realizado con pacientes que desarrollaron infección en el año 2017 (n: 64). Se recogió información sociodemográfica y de infección. Los datos fueron procesados en SPSS 20.0. El proyecto fue aprobado por el comité de ética. Resultados: el sitio topográfico más prevalente fue el tracto urinario (34; 56,7%). El principal factor de riesgo para desencadenar la infección por Klebsiella pneumoniae fue el uso de ventilación mecánica, que presenta un riesgo del 43.8% por la aparición de infecciones por este microorganismo. Se encontró una mayor resistencia para el antimicrobiano piperacilina / tazobactam 52 (82.5%). Conclusión: debido a la alta resistencia a los antibióticos y al gran potencial de contaminación por klebsiella, se deben tomar medidas para minimizar el alto nivel de contaminación y, especialmente, el pronóstico negativo para el paciente

Antimicrobial resistance and antibiotic consumption in Mexican hospitals / Resistencia antimicrobiana y consumo de antibióticos en hospitales mexicanos

Abstract: Objective: To establish the current situation of antimicrobial resistance and antibiotic consumption in Mexican hospitals. Materials and methods: Antimicrobial susceptibility data from blood and urine isolates were collected. Defined daily dose (DDD) of antibiotic consumption/100 occupied beds (OBD) was calculated. Results: Study period: 2016 and 2017. Of 4 382 blood isolates, E. coli and K. pneumoniae were most frequently reported, with antimicrobial resistance >30% for most drugs tested, only for carbapenems and amikacin resistance were <20%. A. baumannii had antimicrobial resistance >20% to all drugs. Resistance to oxacillin in S. aureus was 20%. From 12 151 urine isolates, 90% corresponded to E. coli; resistance to ciprofloxacin, cephalosporins and trimethoprim/sulfamethoxazole was >50%, with good susceptibility to nitrofurantoin, amikacin and carbapenems. Global median antimicrobial consumption was 57.2 DDD/100 OB. Conclusions: This report shows a high antimicrobial resistance level in Gram-negative bacilli and provides an insight into the seriousness of the problem of antibiotic consumption.

Resumen: Objetivo: Establecer la situación actual de la resistencia antimicrobiana y el consumo de antibióticos en hospitales mexicanos. Material y métodos:F Se colectaron datos de susceptibilidad antimicrobiana de aislamientos de sangre y orina. Se calculó la dosis diaria definida (DDD) del consumo de antibióticos/100 estancias. Resultados: Periodo de estudio de 2016 a 2017. De 4 382 aislamientos en sangre, E. coli y K. pneumoniae fueron las más frecuentes, con resistencia >30% a la mayoría de las drogas evaluadas; sólo para carbapenémicos y amikacina la resistencia fue <20%. A. baumannii tuvo resistencia >20% a todos los fármacos. La resistencia a oxacilina en S. aureus fue de 20%. De 12 151 aislamientos en urocultivos, 90% correspondió a E. coli; la resistencia a ciprofloxacina, cefalosporinas y trimetoprima/sulfametoxazol fue >50%, con buena susceptibilidad a nitrofurantoína, amikacina y carbapenémicos. La mediana del consumo global de antibióticos en DDD/100 estancias fue de 57.2. Conclusiones: Este reporte muestra el nivel elevado de resistencia en bacilos Gram-negativos y brinda una perspectiva de la gravedad del problema del consumo de antibióticos.

Prevalence of Klebsiella pneumoniae carbapenemase - and New Delhi metallo-beta-lactamase-positive K. pneumoniae in Sergipe, Brazil, and combination therapy as a potential treatment option

Abstract INTRODUCTION: Carbapenem-resistant Klebsiella pneumoniae infection lacks treatment options and is associated with prolonged hospital stays and high mortality rates. The production of carbapenemases is one of the most important factors responsible for this multi-resistance phenomenon. METHODS: In the present study, we analyzed the presence of genes encoding carbapenemases in K. pneumoniae isolates circulating in one of the public hospitals in the city of Aracaju, Sergipe, Brazil. We also determined the best combination of drugs that display in vitro antimicrobial synergy. First, 147 carbapenem-resistant K. pneumoniae isolates were validated for the presence of blaKPC, bla GES, bla NDM, bla SPM, bla IMP, bla VIM, and bla OXA-48 genes using multiplex polymerase chain reaction. Thereafter, using two isolates (97 and 102), the role of double and triple combinational drug therapy as a treatment option was analyzed. RESULTS: Seventy-four (50.3%) isolates were positive for bla NDM, eight (5.4%) for bla KPC, and one (1.2%) for both bla NDM and bla KPC. In the synergy tests, double combinations were better than triple combinations. Polymyxin B and amikacin for isolate 97 and polymyxin B coupled with meropenem for isolate 102 showed the best response. CONCLUSIONS: Clinicians in normal practice use multiple drugs to treat infections caused by multi-resistant microorganism; however, in most cases, the benefit of the combinations is unknown. In vitro synergistic tests, such as those described herein, are important as they might help select an appropriate multi-drug antibiotic therapy and a correct dosage, ultimately reducing toxicities and the development of antibiotic resistance.

Perfil fenotípico de resistência à colistina e tigeciclina em um hospital público no Brasil / Phenotypical profile of colistin and tigecycline resistance in a public hospital in Brazil / Perfil fenotípico de resistencia a la colistina y tigeciclina en un hospital público de Brasil

Justificativa e objetivos: Infecções Relacionadas à Assistência à Saúde (IRAS) causadas por bacilos Gram negativos multirresistentes (BGN-MDR) são consideradas um problema de saúde pública e um impacto nas taxas de mortalidade nas Unidades de Terapia Intensiva (UTI). O objetivo deste estudo foi verificar o perfil fenotípico de resistência à colistina e à tigeciclina, consideradas como último recurso terapêutico aos BGN-MDR. Métodos: Os dados foram coletados nas fichas de busca ativa do serviço de controle de infecções e prontuários médicos de pacientes internados em duas UTIs de um hospital público de Joinville, entre janeiro de 2016 e junho de 2017. Resultados: Ocorreram 256 IRAS por BGN, acometendo principalmente o gênero masculino (62%), com mediana de idade de 65 anos. Entre os BGN, 37% expressaram MDR; sendo as espécies mais frequentes: Klebsiella pneumoniae e (47%), Acinetobacter baumannii (23%) e Stenotrophomonas maltophilia (11%). A resistência de BGN-MDR à colistina e tigeciclina foi de 5% e de 12%, respectivamente; 5% dos isolados foram resistentes aos dois antibióticos. A taxa de óbito entre os pacientes com IRAS por BGN-MDR resistentes à colistina foi mais alta (60%) que aquelas à tigeciclina (45%). Conclusão: K. pneumoniae e A. baumannii produtores de carbapenemases, resistentes a colistina e tigeciclina prevaleceram entre os BGN-MDR, e estiveram associadas a maioria dos óbitos. Essas observações, junto com o alto uso de carbapenêmicos na terapia empírica, mostra a necessidade do uso racional de antimicrobianos.(AU)

Background and objectives: Healthcare-associated Infections (HAIs) caused by multidrug-resistant Gram-negative bacilli (GNB-MDR) are considered a public health problem and have an impact on mortality rates in Intensive Care Units (ICU). The aim of this study was to verify the phenotypic profile of resistance to colistin and tigecycline, considered as the last antimicrobial choice to treat BGNMDR infections. Methods: Data were collected on the active search records of the infection control service and medical records of patients admitted to two ICUs at a public hospital in Joinville between January 2016 and June 2017. Results: There were 256 HAIs caused by GNB, mainly affecting males (62%), with a median age of 65 years. Among GNBs, 37% expressed MDR; the most frequent species were: Klebsiella pneumoniae (47%), Acinetobacter baumannii (23%) and Stenotrophomonas maltophilia (11%). The resistance of GNB-MDR to colistin and tigecycline was 5% and 12%, respectively; 5% of the isolates were resistant to both antibiotics. The death rate among patients with HAIs caused by colistin-resistant GNB-MDR was higher (60%) than those to tigecycline (45%). Conclusion: Carbapenemase-producing K. pneumoniae and A. baumannii, resistant to colistin and tigecycline, prevailed among GNB-MDRs, and were associated with most deaths. These observations, coupled with the high use of carbapenems in empirical therapy, show the need for rational use of antimicrobials.(AU)

Justificación y objetivos: Las Infección nosocomial (IHs) causadas por bacilos Gram negativos multirresistentes (BGN-MDR) se consideran un problema de salud pública y un impacto en las tasas de mortalidad en las Unidades de Terapia Intensiva (UTI). El objetivo de este estudio fue verificar el perfil fenotípico de resistencia a la colistina ya la tigeciclina, consideradas como último recurso terapéutico a los BGN-MDR. Métodos: Los datos fueron recolectados en las fichas de búsqueda activa del servicio de control de infecciones y prontuarios médicos de pacientes internados en dos UTIs de un hospital público de Joinville, entre enero de 2016 y junio de 2017. Resultados: Ocurrieron 256 IHs por BGN, que afectan principalmente al género masculino (62%), con mediana de edad de 65 años. Entre los BGN, el 37% expresó MDR; siendo las especies más frecuentes: Klebsiella pneumoniae (47%), Acinetobacter baumannii (23%) y Stenotrophomonas maltophilia (11%). La resistencia de BGN-MDR a la colistina y tigeciclina fue del 5% y del 12%, respectivamente; 5% de los aislados fueron resistentes a los dos antibióticos. La tasa de muerte entre los pacientes con IH causadas por los BGN-MDR resistentes la colistina fue más alta (60%) que aquellas a tigeciclina (45%). Conclusión: K. pneumoniae y A. baumannii productoras de carbapenemases, resistentes la colistina y la tigeciclina, fueron más frecuentes entre los BGN-MDR y su asociación estuvo presente en la mayoría de las muertes. Estas observaciones, junto con el alto uso de carbapenems en la terapia empírica, muestran la necesidad de un uso racional de los antimicrobianos.(AU)

Análise custo-efetividade de antimicrobianos usados em pacientes infectados por Klebsiella Pneumoniae Carbapenemase / Cost-effectiveness analysis of antimicrobials used in patients infected with Klebsiella Pneumoniae Carbapenemase

Introdução: A infecção por Klebsiella pneumoniae produtora de carbapenemase vem aumentando ao longo dos últimos anos a nível mundial, necessitando do uso de antimicrobianos de última geração. No entanto, o uso destes antimicrobianos e da terapia associada durante a infecção eleva o custo do tratamento sem impactar no aumento da efetividade do mesmo. Objetivo: Realizar análise custo-efetividade de antimicrobianos usados no tratamento de pacientes infectados por Klebsiella pneumoniae produtora de carbapenemase internados em hospital terciário. Método: trata-se de um estudo de custo-efetividade realizado com dados de vida real, originados em uma coorte prospectiva. A efetividade foi avaliada por meio do sucesso terapêutico do tratamento antimicrobiano, negativação do antibiograma, reinfecção e taxa de óbito hospitalar. O custo direto foi mensurado por meio do tratamento antimicrobiano, exames laboratoriais, diária hospitalar e tratamento medicamentoso associado. Resultado: a monoterapia de amicacina apresentou a melhor razão de custo-efetividade (R$ 9.345) por morte evitada ao considerar todos os tratamentos antimicrobianos. Ao ser considerado somente as terapias combinadas, o tratamento baseado em amicacina e meropenem apresentou a melhor razão de custo-efetividade por morte evitada (R$ 13.389). A alteração dos custos e efetividades por meio da análise de sensibilidade reforçaram os dados da análise de custo-efetividade. Conclusão: o tratamento basesado na combinação de amicacina e meropenem pode ser utilizado como alternativa para o tratamento de pacientes infectados por Klebsiella pneumoniae produtora de carbapenemase, pois possui boa relação custo-efetividade e reduz a possibilidade do aumento da resistência bacteriana.

Introduction: Klebsiella pneumoniae carbapenemase infection has increased over the last few years worldwide, requiring the use of state-of-the-art antimicrobial agents. However, the use of these antimicrobials and associated therapy during infection may increase the cost of treatment without impacting the effectiveness of the treatment. Objective: To evaluate the cost-effectiveness analysis of antimicrobials used in the treatment of patients infected with Klebsiella pneumoniae carbapenemase admitted to a tertiary hospital. Method: This is a cost-effectiveness study carried out with real-life data, originated in a prospective cohort. The effectiveness was evaluated through the therapeutic success of antimicrobial treatment, antibiogram negativity, reinfection and hospital death rate. The direct cost was measured through antimicrobial treatment, laboratory tests, hospital daily and associated drug treatment. Results: amikacin monotherapy had the best cost-effectiveness ratio (R$ 9,345.65) when considering all antimicrobial treatments. When considering only the combination therapies, the treatment based on amikacin and meropenem presented the best cost-effectiveness ratio (R$ 13,389.09). The change in costs and effectiveness through the sensitivity analysis reinforced the data of the cost-effectiveness analysis. Conclusion: the treatment based on the combination of amikacin and meropenem can be used as a first alternative for the treatment of patients infected by Klebsiella pneumoniae carbapenemase, since it is cost-effective and reduces the possibility of increased bacterial resistance.

Biologically Synthesized Silver Nanoparticles for Enhancing Tetracycline Activity Against Staphylococcus aureus and Klebsiella pneumoniae

Abstract Phytochemical content of plant extracts can be used effectively to reduce the metal ions to nanoparticles in one-step green synthesis process. In this study, six plant extracts were used for the synthesis of silver nanoparticles (AgNPs). Biologically synthesized AgNPs was characterized using UV-Vis Spectrophotometer, Field Emission Scanning Electron Microscope (FE-SEM), X-ray diffraction (XRD), Energy Dispersive X-ray spectroscopy (EDX) and Fourier Transform Infrared (FTIR) spectroscopy. The individual and combined effects of AgNPs and tetracycline against S. aureus and K. pneumoniae were assessed. Ginger, onion and sidr extracts supported AgNPs formation while arak, garlic and mint extracts failed to convert the silver ions to AgNPs. The present findings revealed significant differences between the tested plant extracts in supporting AgNPs synthesis. AgNPs synthesized by ginger showed the highest individual and combined activity against tested strains followed by AgNPs prepared by sidr then that synthesized by onion. AgNPs significantly enhanced tetracycline activity (p≤0.05) against S. aureus and K. pneumoniae. The results of this study demonstrated that the combination of tetracycline and biologically synthesized AgNPs presented a useful therapeutically method for the treatment of bacterial infection and counterattacking bacterial resistance.

Origanum vulgare L. essential oil inhibits the growth of carbapenem-resistant gram-negative bacteria

Abstract INTRODUCTION: Plant products are sources for drug development against multidrug resistant bacteria. METHODS The antimicrobial activity of Origanum vulgare L. essential oil (OVeo) against carbapenem-resistant strains was assessed by disk-diffusion, microdilution (REMA-Resazurin Microtiter Assay), and time kill assays. RESULTS Carbapenemase production was confirmed for all strains. OVeo exhibited a minimum inhibitory concentration of 0.059% v/v for Klebsiella pneumoniae and Serratia marcescens, and of 0.015 % v/v for Acinetobacter baumannii. A decrease in cell count was observed after a 4 h treatment. CONCLUSIONS OVeo antimicrobial effect was rapid and consistent, making it a candidate for developing alternative therapeutic options against carbapenem-resistant strains.

Emergence of bla NDM-1 associated with the aac(6')-Ib-cr, acrB, cps, and mrkD genes in a clinical isolate of multi-drug resistant Klebsiella pneumoniae from Recife-PE, Brazil

Abstract INTRODUCTION: The emergence of New Delhi metallo-β-lactamase (NDM) is concernig because it reduces the antibiotic therapy options for bacterial infections. METHODS: Resistant and virulent genes from an isolate of Klebsiella pneumoniae derived from a patient with sepsis in a hospital in Recife-PE, Brazil, were investigated using PCR and DNA sequencing. RESULTS: bla NDM-1, aac(6')-Ib-cr and acrB resistance genes, and cps and mrkD virulence genes were detected. CONCLUSIONS To our knowledge, this is the first report on bla NDM-1 in Recife-PE. This detection alerts researchers to the need to control the spread of bla NDM-1 resistance gene by this bacterium in Brazil.

Relationships between phagocytosis, mucoid phenotype, and genetic characteristics of Klebsiella pneumoniae clinical isolates

Abstract INTRODUCTION The relationships between phagocytosis, and mucoid phenotype, plasmid profile and virulence, and resistance genetic characteristics of Klebsiella pneumoniae clinical isolates were evaluated. METHODS Thirty isolates were used to determine the mucoid aspect. Four were selected for analysis of phagocytosis by alveolar macrophages. RESULTS Thirty percent of the samples presented the mucoid phenotype. The phagocytosis rate ranged from 21.5% to 43.43%. Phagocytosis was not correlated with the plasmid profile, but was apparently correlated with mucoid phenotype and antibiotic susceptibility. CONCLUSIONS: Several virulence factors act in parallel in K. pneumoniae to impair host defense.

Performance of "RESIST-3 O.K.N. K-SeT" immunochromatographic assay for the detection of OXA-48 like, KPC, and NDM carbapenemases in Klebsiella pneumoniae in Turkey

ABSTRACT In this study, the performance of the "RESIST-3 O.K.N. K-SeT" (Coris BioConcept, Gembloux, Belgium) immunochromatographic assay was evaluated in 132 Klebsiella pneumoniae comprising 102 carbapenem resistant and 30 carbapenem susceptible isolates. Genotypically known isolates of Gram negative bacteria (n = 22) including various species were also tested by the assay as controls. The isolates tested by the immunochromatographic assay and also were run PCR for bla KPC, bla IMP, bla VIM, bla NDM, and bla OXA-48. The rates of bla NDM, bla OXA-48, and bla KPC in carbapenem resistant isolates were found at 52.9%, 39.2%, and 2.0%, respectively. Both bla NDM and bla OXA-48 were found in six (5.9%) isolates. The results of the assay showed 100% concordance with those obtained by PCR in 132 K. pneumoniae. The agreement between the two methods was found to be identical at the isolate level. The assay also correctly detected all genotypically known isolates of Escherichia coli, Serratia marcescens, Citrobacter freundii, Enterobacter cloacae, K. pneumoniae carrying bla KPC, bla NDM, and/or bla OXA-48. On the other hand, the assay did not exhibit any cross-reaction in control isolates harboring bla IMP and bla VIM. We conclude that the RESIST-3 O.K.N. K-SeT is a reliable, rapid, and user friendly test and we recommend it for routine diagnostic laboratories.

Carbapenem Resistance in Gram-negative Bacteria in South-western Nigeria: The Role of Extended-spectrum lactamase CTX-M-15 / Resistencia al carbapenem en las bacterias gramnegativas en Nigeria Suroccidental: papel de la betalactamasa de espectro extendido tipo CTX-M-15

ABSTRACT Objective: To determine the role of extended-spectrum β-lactamases in carbapenem-resistant Gram-negative bacteria from south-western Nigeria. Methods: Twenty-seven carbapenem-resistant isolates that were found to be non-carbapenemase producers (15 Escherichia coli, 9 Klebsiella pneumoniae and 3 Pseudomonas aeruginosa) were further studied. These isolates were subjected to analysis including phenotypic and genotypic detection of various β-lactamases, efflux activity, outer membrane protein, plasmids replicon typing, detection of transferable genes and resistances and typing using random amplified polymorphic DNA tests. Results: No isolates demonstrated de-repression of efflux, but all showed either complete loss or reduced production of outer membrane proteins. Transconjugants from these strains contained various genes including plasmid-mediated quinolone resistance and extended-spectrum beta-lactamases. All the transconjugants carried the blaCTX-M-15 gene. The transconjugants had varying minimum inhibitory concentrations of carbapenems ranging from 0.03 μg/ml to 8 μg/ml. Varying resistances to other antimicrobial agents were also transferred with the plasmids. The donor isolates were not clonally related by molecular typing. Conclusion: Resistance to carbapenem antibiotics in this sample was not mediated only by carbapenemases but also by production of extended-spectrum β-lactamases (largely CTX-M-15), accompanied by protein loss. This was an important mechanism underpinning carbapenem resistance in these clinical isolates of various species.

RESUMEN Objetivo: Determinar el papel de las betalactamasas de espectro extendido en la resistencia al carbapenem en las bacterias gramnegativas en Nigeria. Métodos: Veintisiete aislados resistentes al carbapenem que fueron hallados productores de no carbapenemasas (15 Escherichia coli, 9 Klebsiella pneumoniae, y 3 Pseudomonas aeruginosa) fueron estudiados con mayor profundidad. Estos aislados fueron sometidos a análisis incluyendo la detección fenotípica y genotípica de varias betalactamasas, la actividad de eflujo, las porinas de la membrana externa, la tipificación del replicón plasmídico, la detección de genes transferibles y resistencias y tipificación usando pruebas de ADN polimórficas amplificadas aleatorias. Resultados: Ninguno de los aislamientos mostró desrepresión de eflujo, pero todos demostraron la pérdida completa o la producción reducida de porinas externas de la membrana. Los transconjugantes de estas cepas contenían varios genes incluyendo resistencia a la quinolona mediada por plásmidos y betalactamasas de espectro extendido. Todos los transconjugantes portaban el gen blaCTX-M-15. Los transconjugantes tenían diversas concentraciones inhibitorias mínimas de carbapenemas que oscilaban entre 0.03 μg/ml y 8 μg/ml. Varias resistencias a otros agentes antimicrobianos fueron también transferidas con los plásmidos. Los aislamientos del donante no estuvieron relacionados clonalmente por tipificación molecular. Conclusión: La resistencia al antibiótico carbapenem en esta muestra no fue mediada solamente por las carbapenemasas, sino también por la producción de betalactamasas de espectro extendido (en gran parte CTX-M-15), acompañado por pérdida de porina. Éste era un mecanismo importante que sustentaba la resistencia al carbapenem en estos aislados clínicos de varias especies.

Increased antimicrobial resistance in Klebsiella pneumoniae from a University Hospital in Rio Grande do Sul, Brazil

Abstract INTRODUCTION The spread of multidrug-resistant Gram-negative bacilli is a health threat, limiting therapeutic options and increasing morbimortality rates. METHODS: This study aimed to evaluate the antimicrobial susceptibility profile of 1805 Klebsiella pneumoniae isolates collected from Hospital Universitário de Santa Maria between January 2015 and December 2016. RESULTS: Resistance to colistin (239.3%), meropenem (74.2%), ciprofloxacin (68%), gentamicin (35.1%), tigecycline (33.9%), imipenem (29.7%), ertapenem (26.8%), and amikacin (21.4%) was found increased. CONCLUSIONS: Infection control measures in the hospitals are necessary for reducing the spread of multidrug-resistant microorganisms and preventing efficacy loss of these drugs.

Mutation and Efflux System are Responsible for Ciprofloxacin Resistance in Klebsiella pneumoniae / Las mutaciones y el sistema de eflujo son responsables de la resistencia a la ciprofloxacina en la Klebsiella pneumoniae

ABSTRACT The main mechanism of quinolone resistance in Klebsiella (K) pneumoniae is caused by mutation of porin-related proteins and efflux pumps. This study aimed to investigate the prevalence of ciprofloxacin-resistant K pneumoniae in burns patients and to understand the role of the AcrAB multidrug efflux system on minimal inhibitory concentration (MIC) of ciprofloxacin. For this reason, 52 K pneumoniae samples were collected from burns patients and evaluated for the mechanism of ciprofloxacin resistance. The results demonstrated that 40 isolates of K pneumoniae were ciprofloxacin-resistant and 35 showed the mutation on gyrA locus. By inhibition of the efflux system, the MIC yield showed a significant decrease. Therefore, it could be concluded that the high rate of mutation on the gyrA locus in combination with quinolone resistance was responsible for ciprofloxacin resistance and by inhibition of AcrA, the resistance rate showed a significant decrease in K pneumoniae isolated from burns patients.

RESUMEN El principal mecanismo de resistencia a la quinolona en las Klebsiella (K) Pneumoniae tiene como causa la mutación de las porinas y las bombas de eflujo. Este estudio tuvo por objetivo investigar la prevalencia de las K pneumoniae resistentes a la ciprofloxacina en pacientes con quemaduras, así como entender el papel del sistema de eflujo multidroga AcrAB en la concentración inhibitoria mínima (CIM) de la ciprofloxacina. Por esta razón, se recogieron 52 muestras de K pneumoniae de pacientes con quemaduras, a fin de evaluar el mecanismo de resistencia a la ciprofloxacina. Los resultados mostraron que 40 aislados de K pneumoniae eran resistentes a la ciprofloxacina y 35 mostraron la mutación en el locus gyrA. Con la inhibición del sistema de eflujo, el rendimiento de CIM tuvo una disminución significativa. Por lo tanto, se pudo concluir que la alta tasa de mutación en el locus gyrA en combinación con la resistencia a la quinolona era responsable de la resistencia a la ciprofloxacina, y por la inhibición de AcrA, la tasa de resistencia mostró una disminución significativa en las K pneumoniae aisladas de los pacientes con quemaduras.

Antibacterial activity of fractions and isolates of Maytenus guianensis Klotzsch ex Reissek (Celastraceae) Chichuá Amazon

Abstract INTRODUCTION This aim of this study was to evaluate the antibacterial activity of fractions and isolates of Maytenus guianensis, a plant species used in Amazonian folk medicine. METHODS A disk diffusion technique was used to investigate the antibacterial potential. RESULTS The hexanic fractions and tingenone B isolate showed inhibitory effects against Staphylococcus aureus and Streptococcus pneumoniae. CONCLUSIONS These results indicate the antibacterial potential of this species and will enable future studies to identify novel therapeutic alternatives from this species.

Tailoring antimicrobials in febrile neutropenia: using faster diagnostic and communication tools to improve treatment in the era of extensively resistant pathogens

ABSTRACT Febrile Neutropenia represents a medical emergency and the use of appropriate antimicrobial therapy is essential for a better outcome. Although being time-consuming, conventional cultures and antimicrobial susceptibility tests remain the golden standard practices for microbiology identification. Final reports are typically available within several days. Faster diagnostic tools, such as species identification trough Matrix Assisted Laser Desorption Ionization-Time of Flight (MALDI-TOF) and molecular techniques might help to shorten time to diagnostic and also guide definitive therapy in this scenario. Here we present a case in which the use of a diagnostic molecular workflow combining MALDI-TOF and real-time PCR for relevant genes codifying antibiotic resistant integrated with instant communication report, led to a tailored and more appropriate treatment in a patient presenting with febrile neutropenia.

Intereactions between doripenem and clavulanate ­ Application of minimal inhibitory concentration analysis and cytometry flow for bactericidal studies

Background: In view of the current low efficacy of bacterial infection treatment the common trend towards searching for antibiotic systems exhibiting synergistic action is well justified. Among carbapenem analogues a particularly interesting option is provided by combinations of clavulanic acid with meropenem, which have proven to be especially effective. Results: Determination of the minimal inhibitory concentration (MIC) along with the method based on flow cytometry constitutes an important tool in the identification of bacterial sensitivity to active substances. Within this study the inhibitory effect of doripenem, clavulanic acid and the doripenem-clavulanate acid system was analyzed in relation to such bacteria as Salmonella enteritidis, Salmonella typhimurium, Staphylococcus aureus, Klebsiella pneumoniae, Escherichia coli, Pseudomonas aeruginosa, Proteus vulgaris, Clostridium butyricum and Clostridium pasteurianum, Acinetobacter baumannii, Enterobacter aerogenes. The lowest MIC, amounting to 0.03 µg/mL, was observed for the doripenem-clavulanate acid system in the case of E. coli ATCC 25922. In turn, the lowest MIC for doripenem applied alone was recorded for K. pneumoniae ATCC 31488, for which it was 0.1 µg/mL. The strain which proved to be most resistant both to doripenem and the doripenem-clavulanate acid system, was A. baumannii, with MIC of 32 µg/mL (clinical isolate) and 16 µg/mL (reference strain). Cytometric analysis for P. aeruginosa ATCC 27853 and S. aureus ATCC 25923 showed changes in cells following exposure to limiting concentrations of the active substance. Conclusions: Analysis of MIC supplies important information concerning microbial sensitivity to active substances, mainly in terms of limiting concentrations causing mortality or vitality of the tested species, which is essential when selecting appropriate antibiotic therapy.

Resistencia plasmídica a colistin por el gen mcr-1 en Enterobacteriaceae en Paraguay / Plasmid-Mediated Colistin Resistance Gene mcr-1 in Enterobacteriaceae in Paraguay

La resistencia a las polimixinas mediada por plásmidos (gen mcr-1) representa una amenaza para la salud pública, puesto que colistina es utilizada en la práctica médica como una de las últimas alternativas para el tratamiento de gérmenes multiresistentes. Este estudio describe la circulaciónde cepas de Enterobacterias que portan este gen de resistencia, aisladas de pacientes hospitalizados, así como también de la comunidad. Los hallazgos de la Red de Vigilancia de la Resistencia a los Antimicrobianos-Paraguay fueron de casi el 5 % (4,7) en cepas remitidas con criterio de sospecha, siendo las especies involucradas Escherichiacoli, Klebsiella pneumoniae y Salmonella Schwarzengrund. Además, por métodos moleculares se confirmaron en todas ellas la portación de otros genes de resistencia (KPC, CTX-M, Qnr B, Qnr S, aac (6`)-Ib-cr) asociados al mcr-1. Palabras claves: Enterobacterias, resistencia, colistina, mcr-1.

Resistance to polymyxins mediated by plasmids (mcr-1 gene) represents a threat to public health, since colistin is used in medical practice, as one of the last alternatives, for the treatment of multi-resistant germs. This study describes the circulation of strains of Enterobacteria that carry this resistance gene, isolated from hospitalized patients, as well as from the community. The findings of the Red de Vigilancia de la Resistencia a los Antimicrobianos­Paraguay were almost 5% (4.7) in strains submitted with suspicion criteria; the species involved being Escherichia coli, Klebsiella pneumoniae and Salmonella Schwarzengrund. In addition, molecular methods confirmed in all of them the carrying of other resistance genes (KPC, CTX-M, Qnr B, Qnr S, aac (6`)-Ib-cr) associated with mcr-1. Key words: Enterobacteria, resistance, colistin, mcr-1.

Characterization of Klebsiella pneumoniae associated with cattle infections in southwest China using multi-locus sequence typing (MLST), antibiotic resistance and virulence-associated gene profile analysis

Abstract Klebsiella pneumoniae is important human and animal pathogen that causes a wide spectrum of infections. In this study, isolates from cattle nasal swabs samples were identified by 16S rRNA, and to evaluate the antimicrobial susceptibility, virulence gene carrying levels, and multilocus sequence typing of K. pneumoniae isolates. 33 isolates of K. pneumoniae were isolated and identified in 213 nasal swabs samples, of which 12 were hypervirulent K. pneumoniae strains. Extended Spectrum Beta-Lactamases genes were found in 93.4% of the strains. Of which, TEM was the most prevalent (93.4%), followed by CTX-M and SHV were 57.6% and 39.4%, respectively. A main mutation pattern of quinoloneresistance-determining region, Thr83-Ieu and Asp87-Asn in gyrA and Ser87-Ile in parC, was detected in 33 K. pneumoniae isolates. All the isolates harbored at least two virulence factor genes, with ureA (97.0%) and wabG (91.0%) exhibiting high carriage rates in 33 K. pneumoniae isolates. MLST revealed 7 sequence types, of which 3 STs (2541, 2581 and 2844) were newly assigned. Using eBURST, ST2844 and ST2541 were assigned to new clonal complex 2844. Our study provides evidence and biological characteristics of K. pneumoniae isolates from cattle upper respiratory tract in Southwest China.