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Introduction: Hospitals around the world have presented multiresistant Acinetobacter sp. outbreaks. The spread of these isolates that harbor an increasing variety of resistance genes makes the treatment of these infections and their control within the hospital environment more difficult. This study aimed to evaluate the occurrence and dissemination of Acinetobacter sp. multiresistant isolates and to identify acquired resistance genes. Methods: We analyzed 274 clinical isolates of Acinetobacter sp. from five hospitals in Porto Alegre, RS, Brazil. We evaluated the susceptibility to antimicrobial, acquired resistance genes from Ambler's classes B and D, and performed molecular typing of the isolates using enterobacterial repetitive intergenic consensus-polymerase chain reaction (ERIC-PCR) technique. Results: A high (68%) percentage of multiresistant isolates of Acinetobacter sp. was observed, and 69% were resistant to carbapenems. We identified 84% of isolates belonging to species A. baumannii because they presented the gene bla . The gene bla was detected in 62% of the isolates, and among these, 98% were resistant to carbapenems. Using the ERIC-PCR technique, we identified clones of Acinetobacter sp. spread among the four hospitals analyzed during the sampling period. Conclusions: The data indicate the dissemination of Acinetobacter sp. isolates among hospitals and their permanence in the hospital after one year.

Revista da Sociedade Brasileira de Medicina Tropical 41(5):470-473, set-out, 2008 ARTIGO/ARTICLEAntibióticos e bactérias resistentes são descartados em grandes quantidades no ambiente 6 como resultado do aumento e freqüente uso indiscriminado de antibióticos nas práticas médicas, veterinárias e agrárias. As águas dos rios são os principais receptores desses poluentes, uma vez que recebem os esgotos urbano, industrial e hospitalar. Os rios são considerados uma das principais fontes de água, direta ou indiretamente, para consumo humano e animal, portanto, esta poluição pode contribuir para a manutenção e até disseminação da resistência bacteriana 5 . O esgoto hospitalar, especificamente, libera uma variedade de substâncias além de antibióticos, tais como fármacos, desinfetantes, anestésicos, metais pesados e drogas ABSTRACTThe aim of this study was to compare sewage samples from Hospital São Vicente de Paulo with water samples from the Passo Fundo river, with regard to the susceptibility profile of Pseudomonas aeruginosa isolates, in order to make inferences about the presence of strains of hospital origin in surface water samples. The statistical significance between the susceptibility profiles of the samples was tested using analysis of variance, and the samples were compared by means of contrasts of interest. One hundred and ninety-eight isolates of Pseudomonas aeruginosa were recovered from the samples analyzed. No phenotype for multiresistance was found in the samples from the Passo Fundo river, although some carbapenem-resistant isolates were identified, thereby indicating the presence of contamination with bacteria derived from an environment under strong selection pressure. Significant differences between the water and hospital effluent samples were observed, based on the analysis of variance by means of contrasts of interest. Key-words:Pseudomonas aeruginosa. Bacterial resistance. Surface water. Hospital sewage.não metabolizadas por pacientes 3 . A ocorrência de ambientes fortemente seletivos para os microrganismos recuperados de efluentes hospitalares, gera um aumento da freqüência de genes de resistência bacteriana. Estudos têm demonstrado que efluentes hospitalares apresentam níveis mais elevados de bactérias entéricas resistentes a antimicrobianos do que efluentes derivados de outras fontes e, que a concentração de antimicrobianos na água que recebe o esgoto hospitalar também é superior, criando um ambiente com forte pressão seletiva 10 . Além disso, as precárias condições de saneamento básico e a falta de tratamento dos efluentes hospitalares podem estabelecer rotas de disseminação de bactérias multirresistentes 1 13 .

The aim of the study was to evaluate the dissemination of multiresistant isolates of Acinetobacter baumannii carrying resistance genes, by samples of wastewater from hospitals in Porto Alegre, Rio Grande do Sul, Brazil. We obtained 303 bacterial isolates from the wastewater of three hospitals in Porto Alegre, Rio Grande do Sul. For each isolate, we determined the profile of susceptibility to antimicrobials and the presence of the genes bla(OXA-23), bla(OXA-24), bla(OXA-51), bla(OXA-58), bla(SPM-1), bla(IMP), and bla(VIM.) The bla(OXA-51) gene was found in 56% of the isolates, indicating the presence of A. baumannii in this environment. Of these, three multiresistant isolates were positive for the bla(OXA-23) gene, in wastewater from two of the hospitals. The results obtained in this study indicate that isolates of A. baumannii which are multiresistant and carry resistance genes such as bla(OXA-51) and bla(OXA-23) are being released into the environment in the wastewater from the hospitals analyzed. Multiresistant Acinetobacter junii, the newly emerging pathogen, were also found among the multiresistant isolates. Hospital wastewater may be crucial to the development and dispersal of multiresistant bacteria, making waterbodies reservoirs of bacterial resistance.

RESUMOIntrodução: O principal mecanismo de resistência emergente entre Enterobacteriaceae é a produção de β-lactamases de espectro estendido, enzimas capazes de hidrolisar cefalosporinasde-amplo-espectro, que são bastante utilizadas na terapia antimicrobiana de infecções por enterobactérias. Embora a resistência a esses agentes apresente grande variabilidade geográfica, os índices de resistência são elevados em diversos países. ABSTRACT Introduction:The main emerging resistance mechanism relating to Enterobacteriaceae is represented by production of extended spectrum β-lactamases (ESBLs). These enzymes have the capacity to hydrolyze broad-spectrum cephalosporins and are greatly used for antimicrobial chemotherapy on enterobacterial infections. Although resistance to these agents presents remarkable geographical variability, the resistance rates are high in many countries. Methods: A retrospective observational cross-sectional descriptive study was developed to evaluate the frequency of ESBLs among Enterobacteriaceae strains obtained from Hospital São Vicente de Paulo, Brazil. Results: ESBL production was noted in 24.8% (n = 208/838) of the isolates evaluated. Isolates of Escherichia coli represented 46.2% (n = 96/208) of the ESBL producers, followed by Enterobacter species (30.3%; n = 63/208). The sensitivity of these isolates to meropenem was 91.4% and to piperacillin/tazobactam, 67.4%. Conclusions: The ESBL levels founded confirm the worldwide concern regarding this resistance mechanism.

Acinetobacter spp is an important pathogen that is responsible for nosocomial infections affecting immunocompromised patients, and it can easily acquire resistance to antimicrobial agents. Hospital sewage is an important means for disseminating genes for resistance to antimicrobial agents, to the microbiota of the environment. Within this context, 30 strains of Acinetobacter spp from the sewage of a hospital in Porto Alegre, Rio Grande do Sul, were analyzed regarding their profile of susceptibility to beta-lactams, quinolones and aminoglycosides, by means of an antibiogram and tests to screen for metallo-beta-lactamases and extended-spectrum beta-lactamases. The profile obtained revealed the presence of multidrug-resistant strains and showed that resistance mechanisms such as the production of extended-spectrum beta-lactamases and efflux pumps may be present in these strains.