Broad-spectrum β-lactamases amongEnterobacteriaceaeof animal origin: molecular aspects, mobility and impact on public health

Abstract

Broad-spectrum β-lactamase genes (coding for extended-spectrum β-lactamases and AmpC β-lactamases) have been frequently demonstrated in the microbiota of food-producing animals. This may pose a human health hazard as these genes may be present in zoonotic bacteria, which would cause a direct problem. They can also be present in commensals, which may act as a reservoir of resistance genes for pathogens causing disease both in humans and in animals. Broad-spectrum β-lactamase genes are frequently located on mobile genetic elements, such as plasmids, transposons and integrons, which often also carry additional resistance genes. This could limit treatment options for infections caused by broad-spectrum β-lactam-resistant microorganisms. This review addresses the growing burden of broad-spectrum β-lactam resistance among Enterobacteriaceae isolated from food, companion and wild animals worldwide. To explore the human health hazard, the diversity of broad-spectrum β-lactamases among Enterobacteriaceae derived from animals is compared with respect to their presence in human bacteria. Furthermore, the possibilities of the exchange of genes encoding broad-spectrum β-lactamases - including the exchange of the transposons and plasmids that serve as vehicles for these genes - between different ecosystems (human and animal) are discussed.

Scientific Opinion on the public health risks of bacterial strains producing extended-spectrum β-lactamases and/or AmpC β-lactamases in food and food-producing animals

“…Several of these plasmidic AmpC enzymes have also been found with increasing frequency in Enterobacteriaceae isolated from food-producing animals and food (Jacoby, 2009;Smet et al, 2009). …”

“…Reviews about this topic have been published by different authors (Carattoli, 2008;Li et al, 2007;Smet et al, 2009;Torres and Zarazaga, 2007). Tables 6 and 7 (and Tables 16 and 17 of Appendix B) show most of the reports published about the detection of ESBL-or AmpC-carrying Enterobacteriaceae in food-producing animals or foods derived from such animals.…”

“…Percentages of samples of food-producing animals or food in which ESBL-carrying E. coli isolates were detected varied from 0.2% to 40.1%, according to the country and the methodology used [ (Smet et al, 2009); Table 6]. Occurrences in the range of 10-40% were found when healthy poultry or pigs were analysed for the presence of ESBL-positive E. coli isolates in Portugal (Costa et al, 2009;Goncalves et al, 2010;Machado et al, 2008), Netherlands (Dierikx et al, 2010a), France (Girlich et al, 2007), and slightly lower percentages were identified in Czech Republic (Kolar et al, 2010).…”

Antimicrobial Resistance in ESBL-Producing Escherichia coli Isolated from Layer and Pig Farms in Thailand

“…carbapenems and colistin [18]. ESBL-producing Escherichia coli have been isolated with increasing frequency from human and animal samples, a development that has drawn considerable attention worldwide [6,24]. Food-producing animals and their surrounding environment colonized with ESBL-producing E. coli have been considered to be potential sources of resistant bacterial infections in the community [24].…”

ESBL-producing bacteria and MRSA isolated from poultry and turkey products imported from Italy

“…ESBL have directly influenced a global change in the epidemiology of β-lactamases since the early 1990s in human medicine and since 2000 in veterinary medicine (Pitout et al 2010;Smet et al 2010). The term extended-spectrum indicates the ability of ESBL producers to hydrolyse a broader spectrum of β-lactam antimicrobials.…”