Institute of Marine Research, Post Box 1870 Nordnes, 5817 Bergen, Norway.
Norwegian Veterinary Institute, Post Box 64, 1431 Ås, Norway.
Int J Food Microbiol. 2023 Dec 16;407:110422. doi: 10.1016/j.ijfoodmicro.2023.110422. Epub 2023 Sep 30.
This work is the first of its kind to report a whole-year and coastal-wide surveillance of antimicrobial resistance (AMR) of Escherichia coli with samples from the EU imposed Norwegian surveillance programme for marine bivalves. In total, 390 bivalve samples collected from January to December in 2016 at 59 different harvest locations, were examined. The occurrence of resistant E. coli in relation to the concentration of E. coli was also analysed. From each sample with E. coli (n = 261), one isolate was susceptibility tested against a panel of 14 antimicrobials from ten classes. The occurrence of resistance to at least one antimicrobial was 8.4 %. Resistance to tetracycline was most commonly detected (5.7 %), followed by resistance to ampicillin (4.6 %) and sulfamethoxazole (3.1 %). The occurrence of extended spectrum cephalosporin (ESC)-resistant E. coli, quinolone-resistant E. coli (QREC) and carbapenem-resistant Enterobacteriaceae (CRE) were detected through selective screening in 3.3 %, 12.8 % and none of the samples, respectively. Among the ESC-resistant E. coli, the bla gene was detected in nine isolates, where two isolates also carried the bla gene, followed by bla in two and bla in one. One isolate was resistant to ESC due to the n.-42C>T mutation in the AmpC gene. Only the presence of QREC clustered significantly (p < 0.013) in space including nine harvest locations. An increased risk (OR 9.4) of detecting ESC-resistant E. coli or QREC was found for samples with E. coli concentrations above the threshold of Class A for direct distribution to the market (i.e. 230 E. coli/100 g). However, five of the ESC-resistant E. coli and 26 of the QREC positive samples, had levels of E. coli below the threshold, thus from areas cleared for sale. Among the 17 ESC-resistant E. coli subjected to whole genome sequencing, two originated from two samples of great scallops and two samples of flat oysters, which are often consumed raw or lightly processed. One of these isolates belonged to the high-risk clone sequence type 131 and carried a plasmid born senB gene encoding the Shigella enterotoxin 2 (ShET2) attributed to cause watery diarrhoea in infections caused by Enteroinvasive E. coli (EIEC). Thus, our study shows that there is a potential risk for transmission of resistant and pathogenic E. coli to the consumers from these products.
本研究首次报告了 2016 年全年对欧盟强制实施的海洋双壳贝类监测计划中采集的来自沿海地区的大肠杆菌的抗生素耐药性（AMR）监测结果。总共对 59 个不同捕捞点的 390 个双壳贝类样本进行了检测。还分析了大肠杆菌耐药率与大肠杆菌浓度的关系。从每个含有大肠杆菌的样本（n=261）中，选择了一个分离株进行了 14 种来自 10 个类别的抗生素药敏试验。至少对一种抗生素耐药的发生率为 8.4%。最常见的耐药种类为四环素（5.7%），其次是氨苄西林（4.6%）和磺胺甲恶唑（3.1%）。通过选择性筛查，在 3.3%、12.8%和 0%的样本中分别检测到了耐头孢菌素的大肠杆菌（ESC-Res E. coli）、耐喹诺酮的大肠杆菌（QREC）和耐碳青霉烯类肠杆菌科（CRE）。在 ESC-Res E. coli 中，bla 基因在 9 个分离株中被检出，其中 2 个分离株还携带了 bla 基因，其次是 bla 和 bla 各 2 个，bla 基因各 1 个。1 个分离株因 AmpC 基因 n.-42C>T 突变而对 ESC 耐药。仅 QREC 的存在在空间上显著聚类（p<0.013），包括 9 个捕捞点。对大肠杆菌浓度高于 A 类直接上市（即 230 E. coli/100g）的样本进行检测时，发现 ESC-Res E. coli 或 QREC 的检出风险增加（OR 9.4）。然而，在 ESC-Res E. coli 中有 5 个和 QREC 阳性样本中有 26 个样本的大肠杆菌浓度低于阈值，来自已清除上市的区域。在对 17 个进行全基因组测序的 ESC-Res E. coli 中，有 2 个来源于大扇贝和扁牡蛎的 2 个样本，这两种贝类通常是生吃或轻度加工的。其中一个分离株属于高风险克隆序列类型 131，携带一个质粒携带的 senB 基因，该基因编码志贺氏肠毒素 2（ShET2），与肠侵袭性大肠杆菌（EIEC）引起的水样腹泻有关。因此，我们的研究表明，这些产品有可能将耐药和致病性大肠杆菌传播给消费者。
