1Department of Medicine, Austin Health, University of Melbourne, Melbourne, VIC Australia.
2Infectious Diseases & Microbiology Departments, Austin Health, Melbourne, VIC Australia.
Antimicrob Resist Infect Control. 2018 Feb 23;7:30. doi: 10.1186/s13756-018-0322-4. eCollection 2018.
Antibiotic misuse in food-producing animals is potentially associated with human acquisition of multidrug-resistant (MDR; resistance to ≥ 3 drug classes) bacteria via the food chain. We aimed to determine if MDR Gram-negative (GNB) organisms are present in fresh Australian chicken and pork products.
We sampled raw, chicken drumsticks (CD) and pork ribs (PR) from 30 local supermarkets/butchers across Melbourne on two occasions. Specimens were sub-cultured onto selective media for third-generation cephalosporin-resistant (3GCR) GNBs, with species identification and antibiotic susceptibility determined for all unique colonies. Isolates were assessed by PCR for SHV, TEM, CTX-M, AmpC and carbapenemase genes (encoding IMP, VIM, KPC, OXA-48, NDM).
From 120 specimens (60 CD, 60 PR), 112 (93%) grew a 3GCR-GNB ( = 164 isolates; 86 CD, 78 PR); common species were (37%), (13%) and (12%), but only one isolate. Fifty-nine (36%) had evidence of 3GCR alone, 93/163 (57%) displayed 3GCR plus resistance to one additional antibiotic class, and 9/163 (6%) were 3GCR plus resistance to two additional classes. Of 158 DNA specimens, all were negative for ESBL/carbapenemase genes, except 23 (15%) which were positive for AmpC, with 22/23 considered to be inherently chromosomal, but the sole isolate contained a plasmid-mediated CMY-2 AmpC.
We found low rates of MDR-GNBs in Australian chicken and pork meat, but potential 3GCR-GNBs are common (93% specimens). Testing programs that only assess for are likely to severely underestimate the diversity of 3GCR organisms in fresh meat.
食用动物中抗生素的滥用可能与人类通过食物链获得耐多药（MDR；对≥3 种药物类别耐药）细菌有关。我们旨在确定新鲜澳大利亚鸡肉和猪肉产品中是否存在耐多药革兰氏阴性（GNB）菌。
我们在两次采集了来自墨尔本 30 家当地超市/肉店的生鸡肉鸡腿（CD）和猪肋骨（PR）。将标本接种于选择性培养基上用于第三代头孢菌素耐药（3GCR）GNB，对所有独特的菌落进行种属鉴定和抗生素敏感性测定。通过 PCR 评估分离株是否携带 SHV、TEM、CTX-M、AmpC 和碳青霉烯酶基因（编码 IMP、VIM、KPC、OXA-48、NDM）。
从 120 个标本（60 个 CD，60 个 PR）中，有 112 个（93%）生长出 3GCR-GNB（ = 164 株；86 个 CD，78 个 PR）；常见的种属是 （37%）、 （13%）和 （12%），但只有一株 分离株。59 株（36%）仅表现出 3GCR，93/163 株（57%）表现出 3GCR 加一种以上抗生素类别的耐药性，9/163 株（6%）表现出 3GCR 加两种以上抗生素类别的耐药性。在 158 个 DNA 标本中，除 23 个（15%）为 AmpC 阳性外，所有标本均为 ESBL/碳青霉烯酶基因阴性，23 个标本中有 22 个被认为是固有染色体，但唯一的 分离株含有一个质粒介导的 CMY-2 AmpC。
我们发现澳大利亚鸡肉和猪肉中的 MDR-GNB 发生率较低，但常见（93%的标本）存在 3GCR-GNB。仅评估 的检测方案可能严重低估新鲜肉类中 3GCR 生物体的多样性。
