title: beta-Lactam resistance and beta-lactamases in bacteria of animal origin.
abstract: beta-Lactams are among the most clinically important antimicrobials in both human and veterinary medicine. Bacterial resistance to beta-lactams has been increasingly observed in bacteria, including those of animal origin. The mechanisms of beta-lactam resistance include inaccessibility of the drugs to their target, target alterations and/or inactivation of the drugs by beta-lactamases. The latter contributes predominantly to beta-lactam resistance in Gram-negative bacteria. A variety of beta-lactamases have been identified in bacteria derived from food-producing and companion animals and may further serve as a reservoir for beta-lactamase-producing bacteria in humans. While this review mainly describes beta-lactamases from animal-derived Escherichia coli and Salmonella spp., beta-lactamases from animal-derived Campylobacter spp., Enterococcus spp., Staphylococcus spp. and other pathogens are also discussed. Of particular concern are the increasingly-isolated plasmid-encoded AmpC-type CMY and extended-spectrum CTX-M beta-lactamases, which mediate acquired resistance to extended-spectrum beta-lactams. The genes encoding these enzymes often coexist with other antimicrobial resistance determinants and can also be associated with transposons/integrons, increasing the potential enrichment of multidrug resistant bacteria by multiple antimicrobial agents as well as dissemination of the resistance determinants among bacterial species. Characterization of beta-lactam-resistant animal-derived bacteria warrants further investigation of the type and distribution of beta-lactamases in bacteria of animal origin and their potential impact on human medicine.
authors.affiliation: Human Safety Division, Veterinary Drugs Directorate, Health Products and Food Branch, Health Canada, 14-11 Holland Avenue, Ottawa, Ontario K1A OK9, Canada. xianzhi_li@hc-sc.gc.ca
authors.forename: Xian-Zhi
authors.initials: XZ
authors.lastname: Li
authors.forename: Manisha
authors.initials: M
authors.lastname: Mehrotra
authors.forename: Shiva
authors.initials: S
authors.lastname: Ghimire
authors.forename: Lateef
authors.initials: L
authors.lastname: Adewoye
mesh_terms: D000820:Animal Diseases / Q000188:drug therapy / Q000382:microbiology*; D000818:Animals; D004926:Escherichia coli / Q000187:drug effects / Q000201:enzymology*; D004927:Escherichia coli Infections / Q000188:drug therapy / Q000382:microbiology / Q000662:veterinary*; D006801:Humans; D012475:Salmonella / Q000187:drug effects / Q000201:enzymology*; D012481:Salmonella Infections, Animal / Q000188:drug therapy / Q000382:microbiology*; D018440:beta-Lactam Resistance; D001618:beta-Lactamases / Q000378:metabolism*; D047090:beta-Lactams / Q000494:pharmacology* / Q000627:therapeutic use
chemical_list: D047090:beta-Lactams; D001618:beta-Lactamases