Lo Yung-Tsun, Wang Chia-Lan, Chen Bai-Hsung, Hu Chung-Wen, Chou Chung-Hsi
Zoonoses Research Center and School of Veterinary Medicine, National Taiwan University, 1, Section 4, Roosevelt Road, Taipei City, 106, Taiwan.
J Food Prot. 2017 May 1;80(5):734-739. doi: 10.4315/0362-028X.JFP-16-336.
We tested 137 samples of domestic shucked oysters and 114 samples of imported oysters collected from traditional retail markets and supermarkets during 2010 and 2011 in Taiwan for the presence of Salmonella. We obtained a total of 91 Salmonella isolates, representing nine serotypes, from 80 of the domestic samples. We did not find any Salmonella in the imported oysters. The presence of Salmonella contamination tended to be specific to the area from which the oysters were harvested: the Dongshih area had a significantly higher contamination rate (68.8%) than the Budai (20.0%) and Wanggong (9.1%) areas. In addition, the rate of Salmonella contamination was higher in oysters that were packed or sold with water (P < 0.05). The most commonly identified Salmonella serotypes were Saintpaul (26.4%), Newport (22.0%), and Infantis (13.2%). We screened the isolates for susceptibility to nine antimicrobials and compared them genetically by using PCR for the class 1 integron (int1), tetA, tetB, and blaPSE-1 genes. Eighteen isolates (19.8%) were resistant to at least one antimicrobial agent, and the most frequent resistances were those to tetracycline and oxytetracycline (n = 12, 14.3%).We detected the antimicrobial resistance genes int1, tetA, tetB, and blaPSE-1 in 16.5, 26.4, 6.6, and 22.0% of the isolates, respectively. Eleven of the 18 antimicrobial-resistant isolates contained one or two int1 cassettes, suggesting that the presence of int1 is highly correlated with antimicrobial resistance in Salmonella isolates from oysters. The consumption of oysters is increasing in Taiwan, and information related to Salmonella contamination in oysters is rather limited. Our results indicate that raw oyster consumption from retail markets in Taiwan is associated with a human health hazard owing to Salmonella, including multidrug-resistant Salmonella strains.
2010年至2011年期间，我们在台湾的传统零售市场和超市采集了137份国产去壳牡蛎样本和114份进口牡蛎样本，检测其中沙门氏菌的存在情况。我们从80份国产样本中总共获得了91株沙门氏菌分离株，代表9种血清型。在进口牡蛎中未发现任何沙门氏菌。沙门氏菌污染的存在往往与牡蛎的收获地区有关：东石地区的污染率（68.8%）明显高于布袋（20.0%）和王公（9.1%）地区。此外，带水包装或销售的牡蛎中沙门氏菌污染率更高（P < 0.05）。最常见的沙门氏菌血清型是圣保罗（26.4%）、纽波特（22.0%）和婴儿型（13.2%）。我们检测了这些分离株对9种抗菌药物的敏感性，并通过PCR检测1类整合子（int1）、tetA、tetB和blaPSE - 1基因对它们进行基因比较。18株分离株（19.8%）对至少一种抗菌药物耐药，最常见的耐药情况是对四环素和土霉素耐药（n = 12，14.3%）。我们分别在16.5%、26.4%、6.6%和22.0%的分离株中检测到抗菌耐药基因int1、tetA、tetB和blaPSE - 1。18株抗菌耐药分离株中有11株含有一个或两个int1基因盒，这表明int1的存在与来自牡蛎的沙门氏菌分离株中的抗菌耐药性高度相关。台湾牡蛎的消费量正在增加，而有关牡蛎中沙门氏菌污染的信息相当有限。我们的结果表明，台湾零售市场上食用生牡蛎因沙门氏菌，包括多重耐药沙门氏菌菌株，会对人类健康造成危害。
