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The clinical importance of extended-spectrum beta-lactamase (ESBL)-producing Escherichia coli has increased steadily over the years. The presence of the blaTEM, blaSHV, and blaCTX-M genes in the environment has been recently recognized as an important issue in the dissemination of resistance to cephalosporins. Food animals are considered important vectors for transfer of ESBL genes from the environment to humans. The objective of this study was to characterize the ESBL genes (blaTEM, blaSHV, and blaCTX-M types) that were most prevalent among 343 ceftazidime-resistant E. coli isolates (17 batches from 12 different farms) obtained from cloacal swabs of broiler chicken in southern Brazil. The blaSHV, blaCTX-M, blaTEM, blaIMP-type, blaVIM-type, blaNDM-1, blaKPC-type, blaGES-type, blaOXA-48, and mcr-1 genes were evaluated by polymerase chain reaction. A total of 27 (7.9%) E. coli isolates were positive for ESBL genes as follows: 24 for blaCTX-M (23 blaCTX-M-2 Group and 1 blaCTX-M-8) and 3 for blaSHV (2 blaSHV-2a and 1 blaSHV-18). A random sample of 32 ceftazidime/cefotaxime-resistant isolates that were negative for ESBL genes were evaluated for the presence of blaCMY-2 and 24 (75%) tested positive. We detected the blaCMY-2 gene in isolates from all farms. All isolates positive for ESBL or blaCMY-2 are considered multidrug resistant (resistant to at least three antibiotic classes). Our results suggest that broiler chickens are an important reservoir of blaCMY-2 and ESBL genes, including blaSHV-2a, described for the first time in animals originating from Brazil in this study, and blaSHV-18, which has never been described in Brazil before. This fact highlights the importance of controlling the use of antibiotics in animal production to reduce environmental sources of resistance genes. [ABSTRACT FROM AUTHOR]

Acinetobacter baumannii is considered an important pathogen of clinical significance that is responsible for a wide range of nosocomial infections. Carbapenem resistance among A. baumannii isolates has increased dramatically in the Past years because of the emergence and dissemination of specific epidemic clones. We aimed to characterize the population structure of A. baumannii isolates from Porto Alegre city, Southern Brazil, in two distinct periods: during the first carbapenem-resistant A. baumannii (CRAB) outbreak (2007–2008) and 5 years later when the CRAB reached endemic levels (2013–2014). The study included 49 CRAB isolates collected in two periods: 2007–2008 (31 isolates) and 2013–2014 (18 isolates). Multilocus sequence typing (MLST) was performed according to Institute Pasteur, followed by eBURST analysis. PCR was used to detect integrase gene, blaNDM, and oxacillinase genes, and also to detect the ISAba1 element upstream blaOXA-23. The eBURST analysis identified the clonal complexes (CCs) CC15, CC32, CC79, CC216, CC221, and CC464 in the first period (2007–2008) and CC1, CC2, CC15, CC79, and CC162 during the endemic period (2013–2014). Molecular analysis by MLST identified 13 new sequence types. As we found A. baumannii with the blaOXA-23 gene of several CCs, it can be concluded that the increase of CRAB infections are not related to a specific clone. Furthermore, the high-risk CC15 and CC79 were related to the first CRAB outbreak and these CCs persisted up to 2014 in Porto Alegre city. The international clones CC1 and CC2 were observed for the first time in only the second period (2013–2014), alerting to the emergence of these clones in Southern Brazil. [ABSTRACT FROM AUTHOR]