Patrones de susceptibilidad antimicrobiana de bacterias gramnegativas aisladas de infecciones del tracto urinario en Venezuela: Resultados del estudio SMART 2009-2012 / Antimicrobial susceptibility patterns of Gram-negative bacteria isolated in urinary tract infections in Venezuela: Results of the SMART study 2009-2012

Introduction: Antimicrobial resistance of pathogens causing urinary tract infection (UTI) is a growing problem, which complicates their effective treatment. Surveillance is needed to guide appropriate empiric therapy. Aim: to describe the susceptibility patterns of Gram-negative bacteria isolated of patients with UTI to twelve antibiotics as part of the Study for Monitoring Antimicrobial Resistance Trends in Venezuela. Materials and Methods: Between 2009-2012 a total of 472 Gram-negative bacteria were isolated from hospitalized patients with UTI. The isolates were sent to Central Laboratory (Central Laboratory of International Health Management Associates) to confirm their identification, and to make susceptibility testing as recommended by the Clinical and Laboratory Standards Institute. Enterobacteriacea comprised 96.6% of the total, where Escherichia coli (76.9%) and Klebsiellapneu-moniae (10.6%) were the most frequent. Extended-spectrum β-lactamases (ESBL) was detected in 21.6% of isolates. Top antimicrobial activity were ertapenem, imipenem, and amikacin (> 90.0%), slightly lower for amikacin (85.1%) in ESBL-producing strains. Resistance rates to fluoroquinolones and ampicillin/sulbactam were high (40 y 64%, respectively). Conclusions: These data suggest a necessary revision of the therapeutic regimens for the empirical treatment of UTI in Venezuela.

Introducción: La resistencia antimicrobiana de patógenos causantes de infecciones del tracto urinario (ITU) es un problema creciente, que complica su tratamiento efectivo. La vigilancia es necesaria para orientar la terapia empírica apropiada. Objetivo: Documentar los patrones de susceptibilidad de bacterias gramnegativas aisladas de pacientes con ITU a doce antimicrobianos como parte del Estudio de Monitoreo de Patrones de Resistencia en Venezuela (SMART). Materiales y Métodos: Entre 2009-2012, un total de 472 bacterias gramnegativas fueron aisladas de pacientes hospitalizados con ITU. Los aislados fueron enviados a un Laboratorio Central (Central Laboratory of International Health Management Associates) para confirmar su identificación y realizar pruebas de susceptibilidad según recomendaciones del Instituto de Estándares Clínicos y de Laboratorio. Resultados: Enterobacteriacea comprendió 96,6% del total, donde Escherichia coli (76,9%) y Klebsiela pneumoniae (10,6%) fueron las más frecuentes. En 21,6% de los aislados fueron detectadas β-lactamasas de espectro extendido (BLEE). Los antimicrobianos con mejor actividad fueron ertapenem, imipenem y amikacina (> 90,0%); ligeramente menor para amikacina (85,1%) en cepas productoras de BLEE. Las tasas de resistencia a quinolonas y ampicilina/ sulbactam fueron elevadas (40 y 64%, respectivamente). Conclusiones: Estos datos sugieren una necesaria revisión de los esquemas terapéuticos para el tratamiento empírico de las ITU en Venezuela.

[Antimicrobial susceptibility patterns of Gram-negative bacteria isolated in urinary tract infections in Venezuela: Results of the SMART study 2009-2012]. / Patrones de susceptibilidad antimicrobiana de bacterias gramnegativas aisladas de infecciones del tracto urinario en Venezuela: Resultados del estudio SMART 2009-2012.

INTRODUCTION: Antimicrobial resistance of pathogens causing urinary tract infection (UTI) is a growing problem, which complicates their effective treatment. Surveillance is needed to guide appropriate empiric therapy. AIM: to describe the susceptibility patterns of Gram-negative bacteria isolated of patients with UTI to twelve antibiotics as part of the Study for Monitoring Antimicrobial Resistance Trends in Venezuela. MATERIALS AND METHODS: Between 2009-2012 a total of 472 Gram-negative bacteria were isolated from hospitalized patients with UTI. The isolates were sent to Central Laboratory (Central Laboratory of International Health Management Associates) to confirm their identification, and to make susceptibility testing as recommended by the Clinical and Laboratory Standards Institute. Enterobacteriacea comprised 96.6% of the total, where Escherichia coli (76.9%) and Klebsiella pneumoniae (10.6%) were the most frequent. Extended-spectrum ß-lactamases (ESBL) was detected in 21.6% of isolates. Top antimicrobial activity were ertapenem, imipenem, and amikacin (> 90.0%), slightly lower for amikacin (85.1%) in ESBL-producing strains. Resistance rates to fluoroquinolones and ampicillin/sulbactam were high (40 y 64%, respectively). CONCLUSIONS: These data suggest a necessary revision of the therapeutic regimens for the empirical treatment of UTI in Venezuela.

Molecular epidemiology of vancomycin-resistant Enterococcus faecium: a prospective, multicenter study in South American hospitals.

Enterococcus faecium has emerged as an important nosocomial pathogen worldwide, and this trend has been associated with the dissemination of a genetic lineage designated clonal cluster 17 (CC17). Enterococcal isolates were collected prospectively (2006 to 2008) from 32 hospitals in Colombia, Ecuador, Perú, and Venezuela and subjected to antimicrobial susceptibility testing. Genotyping was performed with all vancomycin-resistant E. faecium (VREfm) isolates by pulsed-field gel electrophoresis (PFGE) and multilocus sequence typing. All VREfm isolates were evaluated for the presence of 16 putative virulence genes (14 fms genes, the esp gene of E. faecium [espEfm], and the hyl gene of E. faecium [hylEfm]) and plasmids carrying the fms20-fms21 (pilA), hylEfm, and vanA genes. Of 723 enterococcal isolates recovered, E. faecalis was the most common (78%). Vancomycin resistance was detected in 6% of the isolates (74% of which were E. faecium). Eleven distinct PFGE types were found among the VREfm isolates, with most belonging to sequence types 412 and 18. The ebpAEfm-ebpBEfm-ebpCEfm (pilB) and fms11-fms19-fms16 clusters were detected in all VREfm isolates from the region, whereas espEfm and hylEfm were detected in 69% and 23% of the isolates, respectively. The fms20-fms21 (pilA) cluster, which encodes a putative pilus-like protein, was found on plasmids from almost all VREfm isolates and was sometimes found to coexist with hylEfm and the vanA gene cluster. The population genetics of VREfm in South America appear to resemble those of such strains in the United States in the early years of the CC17 epidemic. The overwhelming presence of plasmids encoding putative virulence factors and vanA genes suggests that E. faecium from the CC17 genogroup may disseminate in the region in the coming years.

Streptococcus pneumonae. Evaluación de la resistencia a la penicilina en cepas venezolanas / Streptococcus pneumonae: evolution of the resistance to penicilin in venezuelan cepas

Se estudiaron 108 cepas de streptococcus pneumoniae aisladas de muestras clínicas provenientes de pacientes referidos a los laboratorios de microbiología de los Hopitales Vargas, Centro Médico y Clínicas Caracas durante el período comprendido entre los meses de Enero de 1993 a Agosto de 1993. Una vez verificada la identificación de las cepas objeto de este estudio, se determinó la sensibilidad a penicilina, eritromicina, cefotaxima, cloranfenicol, vancomicina y fosfomicina mediante el método de difusión en agar. Se utilizó como predictor de sensibilidad a la penicilina, el disco de oxacilina de 1 Mg. Se determinó la concentración inhibitoria mínima (C.I.M.) a la penicilina a 8 cepas utilizando el método Etest y se comparó con las C.I.M. para cefotaxima y eritromicina. Utilizando el disco de oxacilina; 92,60 por ciento de las cepas fueron sensibles a penicilina.Si se hubiera utilizado el disco de penicilina como predictor de sensibilidad, un número menor (87,04 por ciento) hubiera sido categorizado como sensible.. Para eritromicina y fosfomicinala sensibilidad fue de 95,37 por ciento y 99,07 por ciento respectivamente, para el resto de los antibióticos la sensicbilidad fue de del 100 por ciento. Con la determinaciónde la C.I.M. con el método Etest se mostró que las cepas con sensibilidad disminuidas tenían una C.I.M.de 0,125Mg/ml. Las C.I.M. para la penicilina en 7 cepas sensibles estuvieron entre 0,008 y 0,016 Mg/ml. Las C.I.M. para cefotaxima y eritromicina en la cepa con sensibilidad diminuidas fueron 0,023 y 0,064 mg/ml. respectivamente, mientras que para las cepas sensibles fue de 0,004 a 0,008mg/ml. para cefotaxima y entre 0,064 a 0,094 para eritromicina