UCIBIO-Applied Molecular Biosciences Unit, Laboratory of Microbiology, Department of Biological Sciences, REQUIMTE Faculty of Pharmacy, University of Porto, Rua Jorge Viterbo Ferreira 228, 4050-313 Porto, Portugal; Associate Laboratory i4HB - Institute for Health and Bioeconomy, Faculty of Pharmacy, University of Porto, Rua Jorge Viterbo Ferreira 228, 4050-313 Porto, Portugal; School of Medicine and Biomedical Sciences (ICBAS), University of Porto, Rua Jorge Viterbo Ferreira 228, 4050-313 Porto, Portugal; Department of Environmental Health, School of Health, Polytechnic Institute of Porto, Rua Dr. António Bernardino de Almeida 400, 420-072 Porto, Portugal.
UCIBIO-Applied Molecular Biosciences Unit, Laboratory of Microbiology, Department of Biological Sciences, REQUIMTE Faculty of Pharmacy, University of Porto, Rua Jorge Viterbo Ferreira 228, 4050-313 Porto, Portugal; Associate Laboratory i4HB - Institute for Health and Bioeconomy, Faculty of Pharmacy, University of Porto, Rua Jorge Viterbo Ferreira 228, 4050-313 Porto, Portugal.
Int J Food Microbiol. 2023 Jan 2;384:109981. doi: 10.1016/j.ijfoodmicro.2022.109981. Epub 2022 Oct 14.
Poultry meat has been a vehicle of antibiotic resistant bacteria and genes. Yet, the diversity of selective pressures associated with their maintenance in the poultry-production chain remains poorly explored. We evaluated the susceptibility of Enterococcus spp. from chicken meat collected 20 years apart to antibiotics, metals, acidic pH and peracetic acid-PAA. Contemporary chicken-meat samples (n = 53 batches, each including a pool of neck skin from 10 single carcasses) were collected in a slaughterhouse facility using PAA as disinfectant (March-August 2018, North of Portugal). Broilers were raised in intensive farms (n = 29) using CuSO and organic acids as feed additives. Data were compared with that of 67 samples recovered in the same region during 1999-2001. All 2018 samples had multidrug resistant-MDR isolates, with >45 % carrying Enterococcus faecalis, Enterococcus faecium or Enterococcus gallinarum resistant to tetracycline, erythromycin, ampicillin, quinupristin-dalfopristin, ciprofloxacin, chloramphenicol or aminoglycosides. Resistance rates were similar (P > 0.05) to those of 1999-2001 samples for all but five antibiotics. The decrease of samples carrying vancomycin-resistant isolates from 46 % to 0 % between 1999-2001 and 2018 was the most striking difference. Isolates from both periods were similarly susceptible to acid pH [minimum-growth pH (4.5-5.0), minimum-survival pH (3.0-4.0)] and to PAA (MIC = 100-120 mg/L/MBC = 140-160 mg/L; below concentrations used in slaughterhouse). Copper tolerance genes (tcrB and/or cueO) were respectively detected in 21 % and 4 % of 2018 and 1999-2001 samples. The tcrB gene was only detected in E. faecalis (MIC > 12 mM), and their genomes were compared with other international ones of chicken origin (PATRIC database), revealing a polyclonal population and a plasmid or chromosomal location for tcrB. The tcrB plasmids shared diverse genetic modules, including multiple antimicrobial resistance genes (e.g. to tetracyclines, chloramphenicol, macrolide-lincosamide-streptogramin B-MLS, aminoglycosides, bacitracin, coccidiostats). When in chromosome, the tcrB gene was co-located closely to merA (mercury) genes. Chicken meat remains an important vehicle of MDR Enterococcus spp. able to survive under diverse stresses (e.g. copper, acid) potentially contributing to these bacteria maintenance and flux among animal-environment-humans.
家禽肉一直是携带抗生素耐药菌和基因的载体。然而,其在禽类生产链中维持所涉及的选择压力的多样性仍未得到充分探索。我们评估了来自相隔 20 年的鸡肉中的肠球菌属对抗生素、金属、酸性 pH 值和过氧乙酸(PAA)的敏感性。2018 年 3 月至 8 月,在葡萄牙北部的一家屠宰场使用 PAA 作为消毒剂,收集了 53 批当代鸡肉样本(每个样本包括来自 10 个单独胴体的颈部皮肤的混合)。肉鸡在密集型农场中饲养(n=29),使用 CuSO 和有机酸作为饲料添加剂。数据与 1999-2001 年同一地区回收的 67 个样本进行了比较。所有 2018 年的样本均为多药耐药(MDR)分离株,超过 45%的分离株携带对四环素、红霉素、氨苄西林、喹努普汀-达福普汀、环丙沙星、氯霉素或氨基糖苷类耐药的屎肠球菌、粪肠球菌或鸡肠球菌。除了五种抗生素外,所有其他抗生素的耐药率与 1999-2001 年的样本相似(P>0.05)。1999-2001 年至 2018 年间,携带万古霉素耐药分离株的样本从 46%降至 0%,这是最显著的差异。两个时期的分离株对酸 pH 值(最小生长 pH 值为 4.5-5.0,最小存活 pH 值为 3.0-4.0)和 PAA(MIC=100-120mg/L,MBC=140-160mg/L;低于屠宰场使用的浓度)均具有相似的敏感性。2018 年和 1999-2001 年的样本中分别检测到铜耐受基因(tcrB 和/或 cueO)的 21%和 4%。tcrB 基因仅在屎肠球菌中检测到(MIC>12mM),并将其基因组与其他国际鸡源性的基因组(PATRIC 数据库)进行了比较,显示出一个多克隆群体和 tcrB 的质粒或染色体位置。tcrB 质粒具有不同的遗传模块,包括多种抗微生物药物耐药基因(例如,四环素、氯霉素、大环内酯-林可酰胺-链阳性菌素 B-MLS、氨基糖苷类、杆菌肽、球虫抑制剂)。当位于染色体上时,tcrB 基因与 merA(汞)基因紧密相邻。鸡肉仍然是 MDR 肠球菌属的重要载体,能够在多种压力(例如铜、酸)下存活,这可能有助于这些细菌在动物-环境-人类之间的维持和传播。