REQUIMTE, Laboratório de Microbiologia, Faculdade de Farmácia, Universidade do Porto, Porto, Portugal.
J Antimicrob Chemother. 2013 Oct;68(10):2245-8. doi: 10.1093/jac/dkt187. Epub 2013 May 29.
The spread of ESBL-producing Enterobacteriaceae among food animals/products has raised concerns about their possible transmission through the food chain. We aimed to characterize piggeries (pigs, piggery environments) as reservoirs of TEM-52- and CTX-M-encoding plasmids and clones.
Forty-three samples from five Portuguese intensive production farms were studied (2006-07). Twenty-two ESBL-producing (13 TEM-52, 6 CTX-M-32, 3 CTX-M-1) Escherichia coli isolates from healthy pigs, feed and liquid manure were further characterized. Standard methods were used for clonal (PFGE, MLST) and plasmid (S1-PFGE, replicon typing, pMLST, RFLP) analysis. PCR and sequencing were used for analysis of blaCTX-M genetic context and plasmid-mediated quinolone resistance genes.
TEM-52 (n = 13/22; 59%), CTX-M-32 (n = 6/22; 27%) and CTX-M-1 (n = 3/22; 14%) were identified in feed (36%), swine faeces (36%), swine hide (9%) and liquid manure (18%) at different farms. Diverse phylogenetic groups and clones were identified among TEM-52 (7 A, 3 B1, 2 B2, 1 D; 8 clones)-producing, CTX-M-1 (1 A, 1 B1, 1 D; 3 clones)-producing and CTX-M-32 (4 A, 2 B1; 4 clones)-producing isolates. However, the ST10 clonal complex was frequent among TEM-52 (n = 6) and CTX-M-32 (n = 3) producers. blaTEM-52 and blaCTX-M-1/-32 genes were identified within epidemic IncI1/ST3 and IncN/ST1 plasmid variants, respectively.
We report for the first time a piggery reservoir for blaTEM-52. The spread of blaTEM-52 and blaCTX-M-1/-32 within and/or between different piggeries was mostly associated with epidemic plasmids and clones previously identified in humans and other animal hosts in different EU countries, highlighting possible distribution along the food chain.
产超广谱β-内酰胺酶（ESBL）肠杆菌科在食用动物/产品中的传播引起了人们对其可能通过食物链传播的关注。我们旨在描述猪场（猪、猪舍环境）作为 TEM-52 和 CTX-M 编码质粒和克隆的储存库。
研究了来自葡萄牙五个集约化生产农场的 43 个样本（2006-07 年）。从健康猪、饲料和液态粪肥中进一步分离出 22 株产 ESBL（13 株 TEM-52、6 株 CTX-M-32、3 株 CTX-M-1）的大肠杆菌。采用 PFGE、MLST 等方法对克隆（PFGE、MLST）和质粒（S1-PFGE、复制子分型、pMLST、RFLP）进行分析。PCR 和测序用于分析 blaCTX-M 遗传结构和质粒介导的喹诺酮耐药基因。
在不同的农场中，饲料（36%）、猪粪便（36%）、猪皮（9%）和液态粪肥（18%）中发现了 TEM-52（n=13/22；59%）、CTX-M-32（n=6/22；27%）和 CTX-M-1（n=3/22；14%）。在 TEM-52（7 种 A、3 种 B1、2 种 B2、1 种 D；8 种克隆）、CTX-M-1（1 种 A、1 种 B1、1 种 D；3 种克隆）和 CTX-M-32（4 种 A、2 种 B1；4 种克隆）产生的菌株中，鉴定出不同的进化群和克隆。然而，ST10 克隆复合体在 TEM-52（n=6）和 CTX-M-32（n=3）生产者中较为常见。blaTEM-52 和 blaCTX-M-1/-32 基因分别位于流行的 IncI1/ST3 和 IncN/ST1 质粒变体中。
我们首次报道了 blaTEM-52 的猪场储存库。blaTEM-52 和 blaCTX-M-1/-32 在不同猪场内部和/或之间的传播主要与在人类和其他欧盟国家的动物宿主中发现的流行质粒和克隆有关，这突出了可能沿食物链分布的情况。
