Diseminación de enterobacterias productoras de carbapenemasas tipo KCP en Venezuela / Spread of carbapenemase-producing Enterobacteriaceae type KCP in Venezuela

La resistencia a carbapenems en la familia Enterobacteriaceae constituye un problema creciente a nivel mundial, siendo el mecanismo de mayor impacto clínico, epidemiológico y microbiológico, la producción de serino-carbapenemasas KPC. Investigar la presencia de carbapenemasas tipo KPC en aislados de Enterobacterias resistentes a carbapenems, provenientes de diversos centros de salud a nivel nacional, durante el período mayo 2010 - junio 2011. En esta investigación se analizaron 91 aislados de Enterobacterias: K pneumoniae (48), E. cloacae (30), E. aerogenes (4), E. coli (2), C. koseri (1), C. freundil (6), con resistencia a carbapenems provenientes de 14 centros de salud. La susceptibilidad antimicrobiana se evaluó siguiendo los criterios de la CLSI 2011. La detección fenotípica de carbapenemasas se realizó mediante el test de Hodge modificado y evaluando la sinergia con el ácido 3-aminofenilborónico 300 µg/disco. Se realizó el Test de Hodge "doble modificado" a los aislados de Enterobacter y Citrobacter. La detección genotípica de carbapenemasas se llevó a cabo mediante PCR utilizando iniciadores para el gen blaKPC. Todos los aislados presentaron a los deinhibición < 22 mm para meropenem y ertapenem. El 95% de los aislados resultaron positivos para el test de Hogde modificado, el test con ácido borónico, y para el gen blaKPC. En el test de Hodge "doble modificado", se observó 100% de positividad. La resistencia a carbapenems mediada por Carbapenemasas KPC, se ha incrementado en los últimos años en el país y el carácter plasmídico de estas enzimas les permite su fácil diseminación entre diversos géneros de Enterobacterias.

Resistance to carbapenems is the family Enterobacteriaceae is a growing problem around the world, being production of KPC serino-carbapenemase, the mayor impact clinical, epidemiological and microbiological mechanism. To investigate the presence of KPC carbapenemases in isolates of Enterobacterias resistant to carbapenems, from various health centers nationwide, during the period May-2010 June 2011. In this study were analyzed 91 Enterobacterias isolates: K. pneumoniae (48), E. cloacae (30), E. aerogenes (4), E. coli (2), C. koseri (1), C. freundii (6), with resistance to carbapenems from 14 health centers. Antimicrobial susceptibility was evaluated according to the criteria of the CLSI 2011. Phenotypic detection of carbapenemases was performed by Modified Hodge Test and it was evaluated the synergy with the 3-aminophenylboronic 300 µg/disc. Test were done with "double Modified" Hodge to Enterobacter and Citrobacter isolates. Genotypic detection of carbapenemases was performed out by using PCR primers for the gene blaKPC. All isolated showed inhibition zones <22 mm for meropenem and ertapemen. The 95% of the isolates were positive for Hogde Modified Test, test with boronic acid, and to blaKPC gene. By performing "Double Modified" Hodge`s essay , we observed a 100% of positivity. Resistance to carbapenems mediated by KPC carbapenemases has increased in the last few years in the country, and plasmidic characterization of these enzymes allows easily dissemination among different genera of Enterobacteriaceae.

First occurrence of blaOXA-58 in Acinetobacter baumannii isolated from a clinical sample in Southern Brazil

This is the first report of an Acinetobacter baumannii from clinical origin carrying the blaOXA-58 gene in Brazil. The isolate included in this study was from a patient during an outbreak in Porto Alegre, RS, Southern Brazil, in 2007. It was resistant to most of the beta-lactams tested, it has also the blaOXA-65 gene and the ISAba1 sequence located upstream to both blaOXA genes detected and it has a MIC of imipenem of 64 ìg/mL.

Carbapenem-resistant Acinetobacter baumannii outbreak at university hospital / Caracterização de cepas de Acinetobacter baumannii durante um surto de infecção hospitalar

Nineteen clonally related imipenem-resistant Acinetobacter baumannii isolates were recovered from eight intensive care unit patients. All isolates harboured blaOXA-51-like â-lactamase genes and showed the absence of 22 kDa fraction in outer membrane porin profile analysis. It suggests a combination of two mechanisms as responsible for carbapenemresistant phenotypes.

Foram isoladas 19 cepas monoclonais de 8 pacientes da unidade de terapia intensiva, resistentes aos carbapenêmicos. Todas as cepas apresentaram o gene blaOXA-51-like e por análise do perfil de proteínas de membrana notou-se ausência da fração de 22 kDa, sugerindo a combinação de dois mecanismos de resistência aos carbapenêmicos.

Disseminação de Metalo-ß-Lactamases: triagem revela a presença do gene BLA SPM-1 em efluente hospitalar no Sul do Brasil / Spread of Metalo-ß-Lactamases: screening reveals the presence of a BLA SPM-1 gene in hospital sewage in southern Brazil

Of 396 Pseudomonas aeruginosa strains isolated from hospital sewage, the blaSPM-1 gene was confirmed in nine. This is the first report of environmental P. aeruginosa strains carrying the blaSPM-1 gene in Brazil. The carbapenem resistance, already disseminated among clinical isolates, has been detected among environmental isolates.

Ao todo, 396 isolados de Pseudomonas aeruginosa foram estudados. O gene blaSPM-1 foi encontrado em nove isolados de efluente hospitalar. Este estudo é o primeiro relato de isolados ambientais de P. aeruginosa com o gene blaSPM-1no Brasil. A resistência aos carbapenêmicos, amplamente disseminada entre isolados clínicos, já é detectada em isolados ambientais.

Antimicrobial susceptibility of Klebsiella pneumoniae producing extended-spectrum ß-lactamase (ESBL) isolated in hospitals in Brazil

The prevalence of Klebsiella pneumoniae producing extended-spectrum ß-lactamase (ESBL) has been increasing all over the world. Infections caused by ESBL producing isolates are difficult to detect with current susceptibility test, and are difficult to treat. ESBLs confer resistence to all currently available ß-lactam, except carbapenems. In addition, ESBL, production is usually associated with resistence to other classes of antimicrobial agents such as aminoglycosides and quinolones. The objective of this study was to evaluate in vitro susceptibility patterns of ESBL producing K. pneumoniae isolated in Brazil. Seventy-two strains were tested using E test against 30 antimicrobial agents, inclusing carbapenems, second and third generation cephalosporins, aminoglycosides, quinolones, and some new compounds. The most active compounds (i.e. 100 percent susceptibility) were meropenem (MIC90,0.125µg/mL), imipenem (MIC90,0.25µg/mL), and cefotetan (MIC90,2µg/mL). Ciprofloxacin (MIC90, 1µg/mL, 94 percent susceptibility) and cefepime (MIC90, 6µg/mL, 92 percent susceptibility), were also very active against our collection of ESBL producing K. pneumoniae. None of the six aminoglycosides showed good activity against these strains (16 percent to 41 percent susceptibility) and only 39 percent of the isolates were susceptible to piperacillin/tazobactam. The results of our study indicated that the carbapenems are most active compounds against ESBL producing K.pneumoniae in Brazil, and ciprofloxaxin remains very active against these strains. Cefotetan and cefepine were also very active against ESBL producing K.pneumoniae in Brazil; however, further studies are necessary to evaluate the role of these cephalosporins in the treatment of infections due to ESBL producing strains.