Microbiology Research Group, Institute of Innovation, Science and Sustainability, Federation University Australia, Mount Helen Campus, PO Box 663, Ballarat, VIC 3353, Australia.
Microbiology Research Group, Institute of Innovation, Science and Sustainability, Federation University Australia, Gippsland Campus, PO Box 3191, Churchill, VIC 3841, Australia.
J Appl Microbiol. 2024 Aug 5;135(8). doi: 10.1093/jambio/lxae194.
Antibiotic resistance is a global health crisis. Roughly two-thirds of all antibiotics used are in production animals, which have the potential to impact the development of antibiotic resistance in bacterial pathogens of humans. There is little visibility on the extent of antibiotic resistance in the Australian food chain. This study sought to establish the incidence of antibiotic resistance among enterococci from poultry in Victoria.
In 2016, poultry from a Victorian processing facility were swabbed immediately post-slaughter and cultured for Enterococcus species. All isolates recovered were speciated and tested for antibiotic susceptibility to 12 antibiotics following the Clinical Laboratory Standards Institute guidelines. A total of 6 farms and 207 birds were sampled and from these 285 isolates of Enterococcus were recovered. Eight different enterococcal species were identified as follows: E. faecalis (n = 122; 43%), E. faecium (n = 92; 32%), E. durans (n = 35; 12%), E. thailandicus (n = 23; 8%), E. hirae (n = 10; 3%), and a single each of E. avium, E. gallinarum, and E. mundtii. Reduced susceptibility to older classes of antibiotics was common, in particular: erythromycin (73%), rifampin (49%), nitrofurantoin (40%), and ciprofloxacin (39%). Two vancomycin-intermediate isolates were recovered, but no resistance was detected to either linezolid or gentamicin.
The relatively high numbers of a recently described species, E. thailandicus, suggest this species might be well adapted to colonize poultry. The incidence of antibiotic resistance is lower in isolates from poultry than in human medicine in Australia. These results suggest that poultry may serve as a reservoir for older antibiotic resistance genes but is not driving the emergence of antimicrobial resistance in human bacterial pathogens. This is supported by the absence of resistance to linezolid and gentamicin.
抗生素耐药性是全球健康危机。大约三分之二的抗生素用于生产动物，这有可能影响人类病原菌中抗生素耐药性的发展。澳大利亚食物链中抗生素耐药性的程度鲜为人知。本研究旨在确定维多利亚州家禽中肠球菌的抗生素耐药率。
2016 年，从维多利亚州的一家加工厂立即对家禽进行了屠宰后采样，并培养肠球菌属。根据临床和实验室标准协会的指南，对所有回收的分离物进行了种特异性鉴定，并测试了对 12 种抗生素的药敏性。共对 6 个农场和 207 只禽类进行了采样，从中回收了 285 株肠球菌分离株。鉴定出了 8 种不同的肠球菌：粪肠球菌（n=122；43%）、屎肠球菌（n=92；32%）、耐久肠球菌（n=35；12%）、鸟肠球菌（n=23；8%）、赫氏肠球菌（n=10；3%），以及单一的鸡肠球菌、鸽肠球菌和蒙氏肠球菌。对旧类抗生素的敏感性降低很常见，特别是：红霉素（73%）、利福平（49%）、呋喃妥因（40%）和环丙沙星（39%）。回收了 2 株万古霉素中介分离株，但未检测到对利奈唑胺或庆大霉素的耐药性。
最近描述的种，即泰国肠球菌的相对较高数量表明，该种可能很好地适应了家禽的定植。家禽分离株的抗生素耐药率低于澳大利亚的人类医学。这些结果表明，家禽可能是旧抗生素耐药基因的储存库，但不会导致人类病原菌中出现抗微生物耐药性。这一点得到了利奈唑胺和庆大霉素耐药性缺失的支持。
