Pyomelanin biosynthetic pathway in pigment-producer strains from the pandemic Acinetobacter baumannii IC-5

BACKGROUND Acinetobacter baumannii outbreaks have been associated with pandemic International Clones (ICs), but the virulence factors involved with their pathogenicity are sparsely understood. Pigment production has been linked with bacterial pathogenicity, however, this phenotype is rarely observed in A. baumannii. OBJECTIVES This study aimed to characterise the reddish-brown pigment produced by A. baumannii strains, and to determine its biosynthetic pathway by genomic approaches. METHODS Pigment characterisation and antimicrobial susceptibility were conducted by phenotypic tests. The clonal relationship was obtained by pulsed field gel electrophoresis (PFGE) and multi-locus sequence typing (MLST). The genome of an A. baumannii was obtained for characterisation of genes involved with pigment production. FINDINGS The pyomelanin was the pigment produced by A. baumannii. Strains were extensively drug resistant and belonged to the IC-5/ST79. The pyomelanin biosynthetic pathway was determined and presented a particular architecture concerning the peripheral (tyrB, phhB and hpd) and central (hmgB, hmgC and hmgR) metabolic pathway genes. The identification of a distant HmgA homologue, probably without dioxygenase activity, could explain pyomelanin production. Virulence determinants involved with adherence (csuA/BABCDE and a T5bSS-carrying genomic island), and iron uptake (basABCDEFGHIJ, bauABCDEF and barAB) were characterised. MAIN CONCLUSION There is a biosynthetic pathway compatible with the pyomelanin production observed in persistent A. baumannii IC-5 strains.

Investigation of carbapenemases and aminoglycoside modifying enzymes of Acinetobacter baumannii isolates recovered from patients admitted to intensive care units in a tertiary-care hospital in Brazil

Abstract INTRODUCTION: Acinetobacter baumannii are opportunistic bacteria, highly capable of acquiring antimicrobial resistance through the production of carbapenemases and aminoglycoside modifying enzymes (AMEs). METHODS: Carbapenemase and AME genes were investigated in A. baumannii recovered from inpatients of a Brazilian hospital. RESULTS: The key genes found were bla OXA-51-like, the association ISAba1- bla OXA-23-like, and the AME genes aph(3´)-VI, aac(6´)-Ib, aac(3)-Ia, and aph(3´)-Ia. Different clusters spread through the institution wards. CONCLUSIONS: The dissemination of bla OXA-23-like and AME-carrying A. baumannii through the hospital highlights the need for improved preventive measures to reduce the spread of infection.

Prevalence and molecular analysis of multidrug-resistant Acinetobacter baumannii in the extra-hospital environment in Mthatha, South Africa

ABSTRACT Introduction: The presence of Acinetobacter baumannii outside hospitals remains unclear. This study aimed to determine the prevalence of multidrug-resistance (MDR) A. baumannii in the extra-hospital environment in Mthatha, South Africa and to investigate the frequency of carbapenemase-encoding genes. Material and Methods: From August 2016 to July 2017 a total of 598 abattoir samples and 689 aquatic samples were collected and analyzed presumptively by cultural methods for the presence of A. baumannii using CHROMagar™ Acinetobacter medium. Species identification was performed by autoSCAN-4 (Dade Behring Inc., IL) and confirmed by the detection of their intrinsic blaOXA-51 gene. Confirmed MDR A. baumannii isolates were screened for the presence of carbapenemase-encoding genes, ISAba1 insertion sequence and integrase intI1. Results: In total, 248 (19.3%) Acinetobacter species were isolated. Acinetobacter. baumannii was detected in 183 (73.8%) of which 85 (46.4%) and 98 (53.6%) were recovered from abattoir and aquatic respectively. MDR A. baumannii was detected in 56.5% (48/85) abattoir isolates and 53.1% (52/98) aquatic isolates. Isolates showed high resistance to antimicrobials most frequently used to treat Acinetobacter infections such as piperacillin/tazobactam; abattoir (98% of isolates resistant), aquatic (94% of isolates resistant), ceftazidime (84%, 83%), ciprofloxacin (71%, 70%), amikacin (41%, 42%), imipenem (75%, 73%), and meropenem (74%, 71%). All the isolates were susceptible to tigecycline and colistin. All the isolates carried blaOXA-51-like. The blaOXA-23 was detected in 32 (66.7%) abattoir isolates and 11 (21.2%) aquatic isolates. The blaOXA-58-like was positive in 7 (14.6%) and 4 (7.7%) abattoir and aquatic isolates, respectively. Both groups of isolates lacked blaOXA-24-like, blaIMP-type, blaVIM-type, blaNDM-1, blaSIM, blaAmpC, ISAba1 and inI1. Isolates showed high level of Multiple Antibiotic Resistance Index (MARI) ranging from 0.20-0.52. Conclusion: Extra-hospital sources such as abattoir and aquatic environments may be a vehicle of spread of MDR A. baumannii strains in the community and hospital settings.

Epidemiología molecular de aislados de Acinetobacter baumannii resistentes a carbapenems en Argentina / Molecular epidemiology of carbapenem-resistant isolates of Acinetobacter baumannii in Argentina

Se estudiaron 100 aislados consecutivos y no epidemiológicamente relacionados de Acinetobacter baumannii resistentes a los carbapenems, recuperados entre enero y agosto de 2016 de muestras clínicas en 11 hospitales de 10 provincias de la Argentina, ubicadas en distintas regiones del país. Los genes que codifican las carbapenemasas de Ambler clase D y clase B se investigaron mediante la técnica de PCR utilizando cebadores específicos. Todos los aislados se agruparon mediante las técnicas de 3-locus sequence typing y la secuenciación del gen blaOXA-51-like. El gen blaOXA-23 se recuperó en todos los aislados estudiados. La población de A. baumannii resistente a carbapenems en Argentina estuvo asociada, principalmente, con ST1 (45%), ST25 (34%) y ST79 (15%). ST25 se recuperó en todas las regiones estudiadas y no se detectó CC2.

One hundred sequential, epidemiologically unrelated carbapenem-resistant- Acinetobacter baumannii isolates from 11 hospitals in 10 Argentine provinces were collected between January and August 2016. Genes coding for Ambler class D and B carbapenemases were investigated by PCR using specific primers. All isolates were typed using the 3-locus sequence typing and b/aOXA-51-like sequence-based typing techniques. The blaOXA-23 gene was recovered in all isolates studied. The population of carbapenem-resistant- A. baumannii in Argentina was principally associated with ST1 (45%), ST25 (34%) and ST79 (15%). ST25 was recovered in all the regions studied and CC2 was not detected.

Carga y tipología microbiana relacionada con infecciones asociadas a la asistencia sanitaria en servicios clínicos / The microbial weight and type and its relationship with associated infections in health care

RESUMEN Introducción: Las infecciones asociadas a la asistencia sanitaria repercuten en la calidad de los servicios de salud, causando prolongación en la estancia hospitalaria, aumento en costos de atención, riesgo para la vida de los pacientes. A pesar de los intentos por mejorar esta situación, la problemática aún persiste. Objetivo: Determinar la carga y tipología microbiana relacionada con las infecciones asociadas a la asistencia sanitaria en servicios clínicos. Métodos: Estudio cuantitativo, descriptivo, correlacional, diseño no experimental, realizado en servicios Quirúrgica y Unidad de Cuidados Intensivos de un Hospital de Santa Marta, Colombia, durante abril a septiembre de 2014. De manera intencional se tomaron muestras de laboratorio a pacientes, trabajadores, espacios físicos y equipos. El análisis de la información se realizó mediante frecuencias absolutas y relativas, así como correlación de Pearson. Resultados: Quirúrgica reportó infección de herida quirúrgica (100 por ciento), aislando Pseudomona aeruginosa en 66,66 por ciento de casos; cinco espacios positivos (60,00 por ciento Staphylococcus albus coagulasa negativo y 40,00 por ciento Streptococcus ssp). Dos equipos resultaron positivos para Staphylococcus albus (coagulasa negativo). Unidad de Cuidados Intensivos reportó infecciones urinarias (40,00 por ciento), neumonía (40,00 por ciento) y de herida quirúrgica (20,00 por ciento), siendo Acinetobacter baumannii (40,00 por ciento) el microorganismo más frecuente. En el 100,00 por ciento espacios positivos se aisló Streptococcus ssp; ningún germen fue aislado en instrumental y equipos. Conclusiones: Quirúrgica tuvo mayor carga microbiana que la Unidad de Cuidados Intensivos. El germen predominante fue Acinetobacter baumanii. La correlación entre germen causal de las Infecciones Asociadas a la Asistencia Sanitaria, espacios físicos y equipos biomédicos resultó débil; entre germen causal e instrumental quirúrgico no existió relación(AU)

ABSTRACT Introduction: Health care-associated infections have an impact on the quality of health care services, thus causing longer stay at hospitals, rise in assistance costs and risks for the patient's life. Despite the attempts at improving this situation, the problem still remains. Objective: To determine the microbial burden and typing related to health care-associated infections in the clinical services. Methods: A quantitative, descriptive, correlative and non-experimental design-type study conducted in the Surgery services and in the Intensive Care Unit of a hospital located in Santa Marta, Colombia, from April to September, 2014. The lab samples were intentionally taken from patients, workers, physical spaces and equipment. The information analysis was based on absolute and relative frequencies as well as Pearson's correlation coefficient. Results: The Surgery Services reported surgical wound infection (100 percent), isolation of Pseudomona aeruginosa in 66.66 percent of cases; five bacteria-positive physical spaces (60 percent to coagulase-negative Staphylococcus albus and 40 percent to Streptococcus spp). Two pieces of equipment were positive to coagulase-negative Staphylococcus albus. The Intensive Care Unit reported urinary infections (40 percent), pneumonia (40 percent) and surgical wound (20 percent), being Acinetobacter baumannii (40 percent) the most frequent. In all the positive physical spaces, Streptococcus spp was isolated, but not a single germ was found in the medical instruments or in the equipment. Conclusions: Surgical Service had higher microbial burden than the Intensive Care Unit. The predominant germ was Acinetobacter baumanni. The correlation among the causative germ of health care-associated infections, the physical spaces and the biomedical equipment was poor whereas the correlation of the causative germ and the surgical instruments was non-existent(AU)

Multidrug-resistant Acinetobacter baumannii clones persist on hospital inanimate surfaces

ABSTRACT Acinetobacter baumannii is one of the most frequent Gram-negative opportunistic pathogens associated with hospital-acquired infection worldwide. We briefly describe A. baumannii isolates that were recovered from surrounding ICU bed surfaces, exhibiting multidrug resistance phenotype and belonging to some widely spread clonal complexes of clinical A. baumannii isolates.

Carbapenem-resistant Acinetobacter baumannii contamination in an intensive care unit

Abstract INTRODUCTION: Acinetobacter baumannii is a major pathogen causing infections in intensive care units (ICUs). In this study, we aimed to evaluate the presence of A. baumannii in an ICU environment and gloves from ICU workers and to characterize the antimicrobial resistance of the isolates in comparison with those isolated from ICU patients at the same hospital. METHODS: ICU samples were collected from March to November 2010. Isolates biochemically characterized as Acinetobacter calcoaceticus-Acinetobacter baumannii complex were evaluated by PCR targeting the 16S rDNA and bla OXA-51 genes. Antimicrobial susceptibility was determined using the disk diffusion method, and carbapenem-resistant isolates were also evaluated for the minimum inhibitory concentration of imipenem using broth microdilution. The presence of the bla OXA-23 gene was evaluated in isolates with reduced susceptibility to carbapenems. RESULTS: A. baumannii was detected in 9.5% (84) of the 886 samples collected from the ICU environment, including from furniture, medical devices, and gloves, with bed rails being the most contaminated location (23.8%; 20/84). Multidrug-resistant (MDR) A. baumannii was found in 98.8% (83/84) of non-clinical and 97.8% (45/46) of clinical isolates. Reduced susceptibility to carbapenems was detected in 83.3% (70/84) of non-clinical and 80.4% (37/46) of clinical isolates. All isolates resistant to carbapenems harbored bla OXA-23. CONCLUSIONS: We found a strong similarity between the antimicrobial susceptibility profiles of non-clinical and clinical A. baumannii isolates. Such data highlight the ICU environment as a potential origin for the persistence of MDR A. baumannii, and hence the ICU may be a source of hospital-acquired infections caused by this microorganism.

The role of the genetic elements bla oxa and IS Aba 1 in the Acinetobacter calcoaceticus-Acinetobacter baumannii complex in carbapenem resistance in the hospital setting

Abstract: INTRODUCTION: Members of the Acinetobacter genus are key pathogens that cause healthcare-associated infections, and they tend to spread and develop new antibiotic resistance mechanisms. Oxacillinases are primarily responsible for resistance to carbapenem antibiotics. Higher rates of carbapenem hydrolysis might be ascribed to insertion sequences, such as the ISAba1 sequence, near bla OXA genes. The present study examined the occurrence of the genetic elements bla OXA and ISAba1 and their relationship with susceptibility to carbapenems in clinical isolates of the Acinetobacter calcoaceticus-Acinetobacter baumannii complex. METHODS: Isolates identified over 6 consecutive years in a general hospital in Joinville, Southern Brazil, were evaluated. The investigation of 5 families of genes encoding oxacillinases and the ISAba1 sequence location relative to bla OXA genes was conducted using polymerase chain reaction. RESULTS: All isolates presented the bla OXA-51-like gene (n = 78), and 91% tested positive for the bla OXA-23-like gene (n = 71). The presence of ISAba1 was exclusively detected in isolates carrying the bla OXA-23-like gene. All isolates in which ISAba1 was found upstream of the bla OXA-23-like gene (n = 69) showed resistance to carbapenems, whereas the only isolate in which ISAba1 was not located near the bla OXA-23-like gene was susceptible to carbapenems. The ISAba1 sequence position of another bla OXA-23-like-positive isolate was inconclusive. The isolates exclusively carrying the bla OXA-51-like gene (n = 7) showed susceptibility to carbapenems. CONCLUSIONS: The presence of the ISAba1 sequence upstream of the bla OXA-23-like gene was strongly associated with carbapenem resistance in isolates of the A. calcoaceticus-A. baumannii complex in the hospital center studied.

Complete genome of the multidrug-resistant Acinetobacter baumannii strain KBN10P02143 isolated from Korea

Acinetobacter baumannii, a strictly aerobic, non-fermentative, Gram-negative coccobacillary rod-shaped bacterium, is an opportunistic pathogen in humans. We recently isolated a multidrug-resistant A. baumannii strain KBN10P02143 from the pus sample drawn from a surgical patient in South Korea. We report the complete genome of this strain, which consists of 4,139,396 bp (G + C content, 39.08%) with 3,868 protein-coding genes, 73 tRNAs and six rRNA operons. Identification of the genes related to multidrug resistance from this genome and the discovery of a novel conjugative plasmid will increase our understanding of the pathogenicity associated with this species.

Caracterización clínica y epidemiológica de pacientes con bacteriemia en la Unidad de Cuidados Intensivos de Medicina Interna y Cirugía. Hospital Roosevelt-Guatemala / Clinical and epidemiological characterization of patients with bacteremia in the Intensive Care Unit of Internal Medicine and Surgery. Roosevelt Hospital-Guatemala

Antecedentes: La bacteriemia constituye un problema de salud prioritario debido al obstáculo que impone al proceso curativo de los pacientes, involucrando al personal y a los sistemas de salud. Objetivo: Caracterizar clínica y epidemiológicamente pacientes con bacteriemia. Materiales y Métodos: Se realizó una revisión retrospectiva de pacientes con hemocultivos positivo del año 2013, en el Intensivo médico-quirúrgico, del Hospital Roosevelt, con instrumento estandarizado, que incluyó: datos demográficos, morbilidades, comorbilidades, registro de morbilidad y mortalidad. Se calcularon intervalos de confianza al 95% y odds ratio (OR). Resultados: De 47 expedientes y 87 hemocultivos, 55% fueron femeninos, con predominio de edad de 30-49 años, en su mayoría, amas de casa. El 49%, presentó una o más condiciones médicas asociadas. La mayoría de casos de bacteriemia fueron asociados a cuidados de salud, de origen secundario. El principal foco infeccioso fue respiratorio. Los principales microorganismos aislados fueron A. baumannii, K. pneumoniae y S. haemolyticus. Los procedimientos invasivos más frecuentes fueron uso de catéter venoso central y periférico. La tasa de letalidad al día 14 fue del 30%. Conclusiones: Se observó predominio de bacteriemias secundarias, asociadas a los cuidados de la salud, cuyos principales microorganismos aislados coinciden con literatura internacional. La mayor mortalidad fue observada en el sexo femenino.(AU)

Background: Bacteremia known as a major public health problem, because of the limitation it causes to the healing process among patients, involving both health care workers, and health system.Objectives: Characterize the clinical and epidemiological profile among patients with bacteremia.Materials and methods: A retrospective review was made, including positive blood culture patients, admitted to the medical and surgical Intensive Care Unit during 2013, with a standardized instrument which included: demographical data, morbidities and co-morbidities, including a morbidity and morta-lity. The statistics included 95% confidence intervals and odds ratio (OR).Results: Of 47 clinical files, 87 blood cultures, 55% were females. The mostly affected age group was the one within 30-49 years, mainly housewives. 49% presented one or more than one associated con-dition. Most cases of bacteremia were secondary, nosocomial and health care associated. The main origin was the respiratory tract. Main microorganisms isolated were A. baumannii, K. pneumoniae and S. haemolyticus. The most frequent invasive dispositive was central and peripheral venous catheteri-zation. The mortality rate at day 14 was 30%.Conclusions: A predominance of secondary bacteremia, health care associated was observed, who-se main isolated microorganisms agree with international literature. The highest mortality rate was observed in the female sex (AU)

Acinetobacter baumannii resistente a carbapenémicos causante de osteomielitis e infecciones de la piel y los tejidos blandos en hospitales de Medellín, Colombia / Carbapenem-resistant Acinetobacter baumannii causing osteomyelitis and infections of skin and soft tissues in hospitals of Medellín, Colombia

Introducción. Acinetobacter baumannii es una bacteria oportunista que infecta a pacientes gravemente enfermos, principalmente con neumonía asociada al uso del respirador y bacteriemia. La aparición de resistencia a los carbapenémicos limita las opciones terapéuticas para el manejo de las infecciones ocasionadas por esta bacteria. Objetivo. Describir las características clínicas y moleculares de las infecciones ocasionadas por A. baumannii resistente a carbapenémicos en hospitales de Medellín. Materiales y métodos. Durante dos años se llevó a cabo un estudio descriptivo de corte transversal en cinco hospitales de Medellín. La información clínica provenía de las historias clínicas. La presencia de carbapenemasas se evaluó mediante el test tridimensional y la técnica de reacción en cadena de la polimerasa. La tipificación molecular se hizo con electroforesis en gel de campo pulsado y tipificación de secuencias de múltiples locus. Resultados. Se incluyeron 32 pacientes, 13 de los cuales presentaban infecciones de la piel y los tejidos blandos (n=7, 21,9 %), y osteomielitis (n=6, 18,7 %). Los porcentajes de resistencia fueron superiores a 80 % para todos los antibióticos evaluados, excepto para la colistina y la tigecilina. Las carbapenemasas OXA-23 y OXA-51, así como la secuencia de inserción IS Aba1 , se detectaron en todos los aislamientos. La electroforesis en gel de campo pulsado reveló una gran diversidad genética en los aislamientos, y la tipificación de secuencias de múltiples locus evidenció la circulación de los clones ST229 y ST758 en la ciudad. Conclusión. Contrario a lo reportado previamente, los resultados del estudio revelaron que la osteomielitis y las infecciones de la piel y los tejidos blandos eran los principales cuadros clínicos causados por A. baumannii resistente a carbapenémicos en instituciones de Medellín, y resaltan su importancia como agente etiológico de este tipo de infecciones.

Introduction: Acinetobacter baumannii is an opportunistic bacterium which infects seriously ill patients, particularly those with ventilator-associated pneumonia and bacteremia. The emergence of resistance to carbapenem limits the options for the treatment of infections caused by this bacterium. Objective: To describe the clinical and molecular characteristics of infections caused by carbapenem-resistant A. baumannii in Medellín hospitals. Materials and methods: A cross-sectional descriptive study was carried out in five Medellín hospitals over a 2-year period. Clinical information was obtained from medical histories of patients. The presence of carbapenemases was evaluated by three-dimensional test and PCR. Molecular typing was performed using PFGE and MLST. Results: The study included 32 patients, 13 of whom presented skin and soft tissue infections (n=7, 21.9%) or osteomyelitis (n=6, 18.7%). Resistance rates of the isolates exceeded 80% for all the antibiotics evaluated except colistin and tigecycline. Carbapenemases OXA-23 and OXA-51, as well as the insertion sequence IS Aba1 , were detected in all the isolates. PFGE revealed high genetic diversity in the isolates and MLST showed clones ST229 and ST758 are circulating in the city. Conclusion: In contrast to previous reports, the results of the present study showed osteomyelitis and infections of skin and soft tissues to be the main infections caused by carbapenem-resistant A. baumannii in Medellín hospitals and revealed its importance as an etiological agent for this type of infections.

Infection with multidrug-resistant gram-negative bacteria in a pediatric oncology intensive care unit: risk factors and outcomes / Infecção por bactérias gram-negativas multirresistentes em uma unidade de terapia intensiva pediátrica oncológica: fatores de risco e resultados

ABSTRACT OBJECTIVE: This study aimed at evaluating the predictors and outcomes associated with multidrug-resistant gram-negative bacterial (MDR-GNB) infections in an oncology pediatric intensive care unit (PICU). METHODS: Data were collected relating to all episodes of GNB infection that occurred in a PICU between January of 2009 and December of 2012. GNB infections were divided into two groups for comparison: (1) infections attributed to MDR-GNB and (2) infections attributed to non-MDR-GNB. Variables of interest included age, gender, presence of solid tumor or hematologic disease, cancer status, central venous catheter use, previous Pseudomonas aeruginosa infection, healthcare-associated infection, neutropenia in the preceding 7 days, duration of neutropenia, length of hospital stay before ICU admission, length of ICU stay, and the use of any of the following in the previous 30 days: antimicrobial agents, corticosteroids, chemotherapy, or radiation therapy. Other variables included initial appropriate antimicrobial treatment, definitive inadequate antimicrobial treatment, duration of appropriate antibiotic use, time to initiate adequate antibiotic therapy, and the 7- and 30-day mortality. RESULTS: Multivariate logistic regression analyses showed significant relationships between MDR-GNB and hematologic diseases (odds ratio [OR] 5.262; 95% confidence interval [95% CI] 1.282-21.594; p = 0.021) and healthcare-associated infection (OR 18.360; 95% CI 1.778-189.560; p = 0.015). There were significant differences between MDR-GNB and non-MDR-GNB patients for the following variables: inadequate initial empirical antibiotic therapy, time to initiate adequate antibiotic treatment, and inappropriate antibiotic therapy. CONCLUSIONS: Hematologic malignancy and healthcare-associated infection were significantly associated with MDR-GNB infection in this sample of pediatric oncology patients.

RESUMO OBJETIVO: Este estudo visou a avaliar os preditores e resultados associados às infecções por bactérias gram-negativas multirresistentes (BGN-MR) em uma unidade de terapia intensiva pediátrica oncológica (UTIP). MÉTODOS: Foram coletados dados com relação a todos os episódios de infecção por BGN que ocorreram em uma UTIP entre janeiro de 2009 e dezembro de 2012. As infecções por BGN foram divididas em dois grupos para comparação: 1) infecções atribuídas a BGN-MR e 2) infecções atribuídas a BGN não multirresistente. As variáveis de interesse incluíram idade, sexo, presença de tumor sólido ou malignidade hematológica, câncer, uso de cateter venoso central, infecção anterior por Pseudomonas aeruginosa, infecção hospitalar, neutropenia nos sete dias anteriores, duração da neutropenia, tempo de internação antes da UTI, duração da internação na UTI e uso de quaisquer dos seguintes nos 30 dias anteriores: agentes antimicrobianos, corticosteroides, quimioterapia ou radioterapia. Outras variáveis incluíram: tratamento antimicrobiano inicial adequado, tratamento antimicrobiano definitivo inadequado, duração do uso de antibióticos adequados, tempo de início da terapia antibiótica adequada, mortalidade em sete dias e mortalidade em 30 dias. RESULTADOS: As análises de regressão logística multivariada mostraram relações significativas entre as BGN-MR e as doenças hematológicas (razão de chance (RC) 5,262; intervalo de confiança de 95% (IC de 95%) 1,282-21,594; p = 0,021) e infecções hospitalares (RC 18,360; IC de 95% 1,778-189,560; p = 0,015). Houve diferenças significativas entre os pacientes com BGN-MR e BGN não MR com relação às seguintes variáveis: recebimento de terapia antibiótica empírica inicial inadequada, tempo para início do tratamento antibiótico adequado e recebimento de terapia antibiótica inadequada. CONCLUSÕES: A malignidade hematológica e a infecção hospitalar foram significativamente associadas à infecção por BGN-MR nessa amostra de pacientes pediátricos oncológicos.

Survey of infection in orthopedic postoperative and their causative agents: a prospective study / Avaliação de infecção no pós-operatório ortopédico e seus agentes causadores: estudo prospectivo

SummaryObjective:to evaluate the cases of wound infections in orthopedic postoperative period.Methods:postoperative patients who developed infection during the period from November 2012 to November 2013 were studied. Secretions were collected during surgery using sterile swabs, and sent for microbiological analysis.Results:during the period analyzed, 38 surgical procedures progressed to infection. The type of surgery presenting the largest number of infections was osteosynthesis, in 36 (94.7%) patients. Among the materials used, 18 (36%) surgeries that used external fixator were infected, and 17 (34%) using plate. The species of bacteria that caused the largest number of infections were Staphylococcus aureus, infecting 16 (43.9%) patients, followed by Acinetobacter baumannii, which infected four (10.5%) patients. Regarding the resistance profile of Gram-positive strains to antibiotics, 100% of Staphylococcus aureus strains were susceptible to vancomycin and 31.3%, to ceftriaxone. As for the Gram-negative bacteria, 100% of Acinetobacter baumannii strains were resistant to ceftriaxone, gentamicin and imipenem.Conclusion:infection control in the postoperative period is necessary, using antibiotics correctly and consciously, avoiding resistance of bacterial agents.

ResumoObjetivo:avaliar os casos de feridas infectadas em pós- -operatório ortopédico.Métodos:foram estudados pacientes de pós-operatório que evoluíram com processo infeccioso, durante o período de novembro de 2012 a novembro de 2013. Foi realizada coleta intraoperatória de secreções com o auxílio de swabs estéreis, e o material foi encaminhado para análise microbiológica.Resultados:durante o período analisado, 38 procedimentos cirúrgicos evoluíram para processo infeccioso. O tipo de cirurgia que apresentou o maior número de infecções foi a osteossíntese, em 36 (94,7%) pacientes. Em relação ao material utilizado, 18 (36%) cirurgias que empregaram fixador externo e 17 (34 %) que fizeram uso de placa se infectaram. A bactéria que causou o maior número de infecções foi a Staphylococcus aureus, acometendo 16 (43,9%) pacientes, seguida pela Acinetobacter baumannii, que acometeu 4 (10,5%) pacientes. Em relação ao perfil de resistência das cepas Gram-positivas aos antibióticos, 100% das cepas de Staphylococcus aureus foram sensíveis à vancomicina, e 31,3%, à ceftriaxona. Quanto às bactérias Gram-negativas, 100% das cepas de Acinetobacter baumannii apresentaram resistência a ceftriaxona, gentamicina e imipenem.Conclusão:o controle de infecções em pós-operatório se faz necessário, utilizando antibióticos de forma correta e consciente, evitando a resistência aos agentes bacterianos.

Trends of 9,416 multidrug-resistant Gram-negative bacteria / Evolução de 9.416 bactérias Gram-negativas multirresistentes.

Summary Objective: a resistance of hospital-acquired bacteria to multiple antibiotics is a major concern worldwide. The objective of this study was to investigate multidrugresistant (MDR) bacteria, clinical specimens, origin of specimen and trends, and correlate these with bacterial sensitivity and consumption of antimicrobials. Methods: 9,416 bacteria of nosocomial origin were evaluated in a tertiary hospital, from 1999 to 2008. MDR was defined for Gram-negative bacteria (GNB) as resistance to two or more classes/groups of antibiotics. Results: GNB MDR increased by 3.7 times over the study period (p<0.001). Acinetobacter baumannii was the most prevalent (36.2%). Over the study period, there were significant 4.8-fold and 14.6-fold increases for A. baumannii and K. pneumoniae (p<0.001), respectively. Sixty-seven percent of isolates of MDR GNB were isolated in intensive care units. The resistance of A. baumannii to carbapenems increased from 7.4 to 57.5% during the study period and concomitant with an increased consumption. Conclusion: that decade showed prevalence of GNB and a gradual increase in MDR GNB. There was an increase in carbapenem resistance of 50.1% during the study. .

Resumo Objetivo: a resistência bacteriana hospitalar a múltiplos antibióticos é uma grande preocupação mundial. O objetivo deste estudo foi conhecer os agentes multidroga-resistentes (MDR), materiais clínicos, origem e evolução, e correlaciona-los à sensibilidade bacteriana e ao consumo de antimicrobianos. Métodos: foram avaliadas 9.416 bactérias de origem nosocomial, em um hospital terciário, durante o período de 1999 a 2008. Foram definidas como MDR as bactérias Gram-negativas (BGN) que apresentaram resistência a duas ou mais classes/grupos de antibióticos. Resultados: as BGN MDR tiveram um aumento global de 3,7 vezes no final do período (p<0,001). O Acinetobacter baumannii foi o mais prevalente (36,2%). Durante o período do estudo, houve um aumento significativo de 4,8 e 14,6 para A. baumannii e K. pneumoniae (p<0,001), respectivamente. Sessenta e sete por cento das BGN MDR foram isoladas em unidade de terapia intensiva. A resistência do A. baumannii aos carbapenêmicos aumentou de 7,4 para 57,5% durante o período, concomitante ao aumento do consumo. Conclusão: durante essa década, houve uma prevalência de BGN e um aumento gradual das BGN MDR. Houve um aumento da resistência aos carbapenêmicos de 50,1% durante o estudo. .

Factores de riesgo para la adquisición y características microbiológicas de las bacteriemias por Acinetobacter baumannii multi-resistente en pediatría: Estudio de casos y controles / Microbiological features and risk factors for acquiring multidrug-resistant Acinetobacter baumannii bacteremia in pediatric patients: Case-control study

Background: Multidrug-resistant Acinetobacter baumannii (MAB) is an important nosocomial pathogen. Objectives: To analyze the risk factors for acquiring MAB, and the clinical and microbiological characteristics of MAB bacteremia (MABB) in children. Materials and Methods: Control-case study 2005-2008. Demographic and clinical data from all MABB and from non-multiresistant gram-negative bacteremias were recorded. Identification at species level, antimicrobial susceptibility tests, time-kill studies and clonally relationships were performed. Stata 8.0 was used for data analysis. Results: A total of 50 MABB and 100 controls were included. Ninety four percent of patients acquired MAB in ICU and the 88% had underlying diseases. All patients had invasive procedures previous to MABB. The median of hospitalization stay previous to MABB was different in cases than in controls (16 vs 7 days, p < 0.001). Five clones were detected among the MABB. Time-killing curves showed bactericidal activity of ampicillin/sulbactam plus gentamicin and polymixin B. Three patients with MAB died. In a multivariate analysis final predictors of MABB were: previous use of broad-spectrum antibiotics [OR: 7,0; IC 95% 1,93-25,0; p: 0,003] and mechanical ventilation [OR: 4,19; IC 95% 1,66-10,0; p: 0,002]. Conclusions: MABB were detected in patients with underlying conditions, invasive procedures and prolonged hospitalization. Predictors of MABB were mechanical previous use of broad-spectrum antibiotics and mechanical ventilation.

Introducción: Acinetobacter baumannii multi-resistente (ABM) es un patógeno intrahospitalario de importancia. Objetivos: Analizar factores de riesgo de adquisición y características clínicas y microbiológicas de las bacteriemias por ABM (BABM) en pediatría. Métodos: Estudio de casos y controles período 2005-2008. Se incluyeron variables demográficas y clínicas de pacientes con BABM y por otros bacilos gramnegativos no ABM. Se realizaron pruebas para identificación de especie, susceptibilidad antimicrobiana y detección feno-genotípica de mecanismos de resistencia, sinergia y clonalidad. Análisis estadístico: Stata 8.0. Resultados: Se incluyeron 50 BABM y 100 controles. El 94% de los pacientes adquirieron la BABM en UCI y 88% tenía patologías subyacentes. La mediana de días de internación previa a la bacteriemia fue mayor en los casos (16 vs 7 días, p < 0,001). Se detectaron cinco clones de ABM. Se encontró efecto bactericida in vitro con polimixina B y con ampicilina/sulbactam+gentamicina. Tres casos fallecieron. Análisis multivariado: predictores finales de BABM fueron: antimicrobiano previo de amplio espectro [OR: 7,0; IC 95% 1,93-25,0; p: 0,003] y asistencia respiratoria mecánica (ARM) [OR: 4,19; IC 95% 1,66-10,0; p: 0,002]. Conclusiones: Las BABM fueron detectadas en pacientes con enfermedad subyacente, con procedimientos invasores previos e internación prolongada. Fueron predictores de BABM el tratamiento antimicrobiano de amplio espectro y ARM previa.

Patrones de resistencia a antibióticos de Acinetobacter baumannii en un hospital de Colombia / Patterns of Acinetobacter baumannii resistance to antibiotics in a Colombian hospital

Identificar patrones de resistencia en los aislamientos de A. baumannii obtenidos en una unidad de cuidados intensivos de Cali, Colombia. Diseño: Estudio descriptivo, prospectivo de corte transversal. Institución: Clínica Universitaria Rafael Uribe Uribe, Cali, Colombia. Materiales: Los aislamientos se obtuvieron de cultivos de muestras de sangre, heridas quirúrgicas, secreción nasal, orina, secreción uretral y puntas de catéter. Intervenciones: Se recolectaron 52 aislamientos durante los años 2009 y 2010. Mediante el análisis del antibiograma se identificaron patrones de resistencia (antibiotipos), se realizó antibiograma cuantitativo y se construyó un cladograma basado en el agrupamiento por el método de promedios aritméticos de grupos apareados no ponderados (conocido en inglés como UPGMA). Principales medidas de resultados: Medida de la concentración mínima inhibitoria (CMI) y el coeficiente de similitud generado por las distancias de los diámetros de los halos de inhibición entre dos aislamientos (antibiograma cuantitativo). Resultados: Se identificaron 5 antibiotipos; el 50 por ciento de los aislamientos se agruparon en el antibiotipo 1, con resistencia a todos los antibióticos y sensibilidad a tigeciclina y sulperazona; el antibiotipo 4 agrupó los aislamientos con resistencia a todos los antibióticos (19,3 por ciento). En el antibiograma cuantitativo se identificaron dos clados con 5 y 47 aislamientos, respectivamente. Conclusiones: Los aislamientos de Acinetobacter baumannii tuvieron pocas diferencias fenotípicas y es probable que presenten alguna de las ß-lactamasas tipo OXA...

To identify patterns of resistance in A. baumannii isolates obtained from an intensive care unit in Cali, Colombia. Design: Prospective cross-sectional descriptive study. Institution: Clínica Universitaria Rafael Uribe Uribe, Cali, Colombia. Materials: Isolates were obtained from cultures of blood, surgical wounds, nasal secretion, urine, urethral discharge and catheter tip samples. Interventions: Fifty-two isolates were collected between 2009 and 2010. Antibiogram analysis was done to identify resistance patterns (antibiotypes), a quantitative susceptibility testing was conducted, and a cladogram based on unweighted pair group method average (UPGMA) was constructed. Main outcome measures: Minimum inhibitory concentration (MIC) and similarity coefficient generated by diameters distances between two isolated inhibition zones (quantitative antibiogram). Results: Five antibiotypes were identified; 50 per cent of isolates were grouped in antibiotype 1, were resistant to all antibiotics, and susceptible to tigecycline and sulperazone; antibiotype 4 grouped isolates resistant to all antibiotics (19.3 per cent). In the quantitative antibiogram two clades with 5 and 47 isolates were identified respectively. Conclusions: Acinetobacter baumannii isolates showed few phenotypic differences and probably present some of ß-lactamases OXA type...

Clinico-pathological Analysis of the Lungs from Patients with Lung Transplantation in a Single Institute in Korea

Recently, the numbers of lung transplantation (LT) has been increased in Korea. However, post-LT outcome has not been successful in all patients, which may be partially affected by the primary lung disease. Therefore comprehensive understanding in original pathological diagnosis of patients with LT would be needed for achieving better clinical outcome. To address this issue, we performed clinico-pathological analysis of the explanted lungs from 29 patients who underwent LT over a 9-yr period in Seoul National University Hospital. Among them, 26 patients received single (1/26) or double (25/26) LT, while heart-lung transplantation was performed in 3 patients. The final clinico-pathological diagnoses were idiopathic pulmonary fibrosis/usual interstitial pneumonia (UIP) (n = 6), acute interstitial pneumonia (AIP)/diffuse alveolar damage (DAD) (n = 4), AIP/non-specific interstitial pneumonia with DAD (n = 1), collagen vascular disease-related interstitial lung disease (CVD-ILD)/DAD (n = 3), CVD-ILD/UIP (n = 1), lymphangioleiomyomatosis (n = 1), bronchiectasis (n = 4), pulmonary arterial hypertension (n = 2), tuberculosis (n = 1), bronchiolitis obliterans (BO) (n = 1), and lung cancer (n = 1). Moreover, 4 patients who had chemotherapy and hematopoietic stem cell transplantation due to hematologic malignancy showed unclassifiable interstitial pneumonia with extensive fibrosis in the lungs. Our study demonstrates that pathology of the explanted lungs from Korean patients with LT is different from that of other countries except for interstitial lung disease and bronchiectasis, which may be helpful for optimization of selecting LT candidates for Korean patients.

Use of Delta Neutrophil Index for Differentiating Low-Grade Community-Acquired Pneumonia From Upper Respiratory Infection

No abstract available.