RESUMO
Extended-spectrum beta-lactamase- (ESBL-) producing Klebsiella (K.) pneumoniae and Escherichia (E.) coli are of critical importance in human and veterinary medicine. Animal food products, especially broiler chickens, are discussed as a possible source for the exposure of humans with antibiotic resistant bacteria. Although the occurrence and vertical transmission of ESBL-/AmpC-producing Enterobacteriaceae in the broiler production has been reported before, detailed investigations concerning the dissemination along the slaughter processing line are missing. In this study, we investigated cross-contamination with ESBL-producing Enterobacteriaceae during the processing of two different broiler flocks in one slaughterhouse. The ESBL-status during the fattening period of the flocks was determined and environmental samples from the slaughterhouse were taken before processing of the respective flocks. These isolates were compared to those found in samples from the carcasses after processing using whole genome sequencing. Phylogenetic analyses of seven ESBL-producing K. pneumoniae and 14 E. coli revealed close relationships between isolates from scalding water and the defeathering machine, respectively, which were collected before the processing of the broiler flocks, to those isolates found in samples from skin and filet of the respective flock carcasses. In conclusion, using high resolution molecular data we found evidence for the cross-contamination of carcasses with ESBL-producing Enterobacteriaceae during scalding and defeathering in the slaughterhouse.
Assuntos
Galinhas/microbiologia , Escherichia coli/classificação , Contaminação de Alimentos , Microbiologia de Alimentos , Klebsiella pneumoniae/classificação , Carne/microbiologia , beta-Lactamases/metabolismo , Matadouros , Animais , Proteínas de Bactérias/genética , Farmacorresistência Bacteriana/genética , Enterobacteriaceae/genética , Enterobacteriaceae/metabolismo , Escherichia coli/genética , Escherichia coli/isolamento & purificação , Escherichia coli/patogenicidade , Infecções por Escherichia coli/microbiologia , Infecções por Escherichia coli/transmissão , Infecções por Escherichia coli/veterinária , Manipulação de Alimentos , Humanos , Infecções por Klebsiella/microbiologia , Infecções por Klebsiella/transmissão , Infecções por Klebsiella/veterinária , Klebsiella pneumoniae/genética , Klebsiella pneumoniae/isolamento & purificação , Klebsiella pneumoniae/patogenicidade , Tipagem de Sequências Multilocus , Filogenia , Doenças das Aves Domésticas/microbiologia , Virulência/genética , Sequenciamento Completo do Genoma , beta-Lactamases/genéticaRESUMO
Food producing animals are considered a reservoir for Extended-spectrum beta-lactamase (ESBL) and AmpC beta-lactamase (AmpC) producing Enterobacteriaceae. Therefore, meat is discussed to be a potential source for the transmission of these resistant bacteria to humans. There is only limited information about the quantitative load of ESBL-/AmpC-producing Enterobacteriaceae in different sample matrices during slaughter and their distribution in the slaughterhouse environment. Therefore, the aim of this study was to determine the prevalence as well as quantitative load of ESBL-/AmpC-producing Enterobacteriaceae in caecum, skin and filet samples of different broiler chicken flocks during slaughter in Germany. In addition, environmental samples were taken during slaughter of the respective flocks. To gain insights into possible transmission routes of ESBL-/AmpC-producing Enterobacteriaceae, the corresponding phylogroup and beta-lactamase genes were determined for selected isolates. ESBL-/AmpC-producing Enterobacteriaceae were detected during slaughter of all seven investigated flocks. On average, 47% (83/175) of caecum, 55% (96/175) of skin, 28% (49/175) of filet and 28% (25/89) of environmental samples harboured ESBL-/AmpC-producing Enterobacteriaceae. Prevalence varied widely between the flocks as well as between the different sample matrices. In about half of the caecum (23/40) and skin (19/40) samples as well as 85% (17/20) of the filet samples, the number of putative ESBL-/AmpC-producing Enterobacteriaceae (cefotaxime resistant Enterobacteriaceae) was below quantification limit. The median of cefotaxime resistant Enterobacteriaceae was 2.5â¯×â¯103â¯cfu/g in caecum, 1.5â¯×â¯103â¯cfu/g in skin and 1.5â¯×â¯102â¯cfu/g in filet samples. The median of cefotaxime resistant Enterobacteriaceae was, depending on the sample matrix, 1-4 log units below the median of total Enterobacteriaceae. Using real-time PCR, in 82% (629/767) of the cefotaxime resistant Enterobacteriaceae at least one of the investigated beta-lactamase genes blaCTX-M, blaSHV, blaTEM, blaAmpC-CIT was detected. The respective resistance genes of 322 isolates were further sequenced. The predominant bla-gene was blaCMY-2 (48%), followed by blaSHV-12 (23%). A contamination from the broiler chicken to the slaughterhouse environment and vice versa seems probable as isolates of the same species and phylogroup, encoding the same resistance genes were detected in all matrices during slaughter of the respective flock as well as in the slaughterhouse environment.
