Li Mengxuan, Wang Ying, Hou Bingyu, Chen Yibao, Hu Ming, Zhao Xiaonan, Zhang Qing, Li Lulu, Luo Yanbo, Liu Yuqing, Cai Yumei
College of Veterinary Medicine, Shandong Agricultural University, Taian, China.
Shandong Academy of Agricultural Sciences, Jinan, China.
Int J Food Microbiol. 2024 Apr 16;415:110642. doi: 10.1016/j.ijfoodmicro.2024.110642. Epub 2024 Feb 28.
Clostridium perfringens is a zoonotic opportunistic pathogen that produces toxins that can cause necrotic enteritis and even "sudden death disease". This bacterium is widely distributed in the intestines of livestock and human, but there are few reports of distribution in aquatic animals (Hafeez et al., 2022). In order to explore the isolation rate of C. perfringens and the toxin genes they carry, 141 aquatic samples, including clams (Ruditapes philippinarum), oysters (Ostreidae), and mud snails (Bullacta exerata Philippi), were collected from the coastal areas of Shandong Province, China. C. perfringens strains were tested for cpa, cpb, etx, iap, cpb2, cpe, netB, and tpeL genes. 45 clam samples were boiled at 100 °C for 5 min before bacteria isolation. 80 strains were isolated from 141 samples with the positive rate being 57 %.And the positive rates of cooked clams was 87 % which was higher than the average. In detection of 8 toxin genes, all strains tested cpa positive, 3 strains netB positive, and 2 cpb and cpe, respectively. 64 strains were selected to analyze the antibiotic resistance phenotype of 10 antibiotics. The average antibiotic resistance rates of the strains to tetracycline, clindamycin, and ampicillin were 45 %, 20 %, and 16 % respectively, and the MIC of 4 strains to clindamycin was ≥128 μg/mL. A high isolation rate of C. perfringens from aquatic animals was shown, and it was isolated from boiled clams for the first time, in which cpe and netB toxin genes were detected for the first time too. The toxin encoded by cpe gene can cause food poisoning of human, thus the discoveries of this study have certain guiding significance for food safety. Antibiotics resistant C. perfringens of aquatic origin may arise from transmission in the terrestrial environment or from antibiotic contamination of the aquaculture environment and is of public health significance.
产气荚膜梭菌是一种人畜共患的机会性病原菌，它产生的毒素可导致坏死性肠炎甚至“猝死病”。这种细菌广泛分布于家畜和人类的肠道中，但在水生动物中的分布报道较少（哈菲兹等人，2022年）。为了探究产气荚膜梭菌的分离率及其携带的毒素基因，从中国山东省沿海地区采集了141份水生样本，包括菲律宾蛤仔、牡蛎和泥螺。对产气荚膜梭菌菌株进行了cpa、cpb、etx、iap、cpb2、cpe、netB和tpeL基因检测。45份蛤仔样本在细菌分离前于100℃煮沸5分钟。从141份样本中分离出80株菌株，阳性率为57%。煮熟蛤仔的阳性率为87%，高于平均水平。在检测的8种毒素基因中，所有菌株的cpa检测均为阳性，3株netB阳性，2株分别为cpb和cpe阳性。选取64株菌株分析其对10种抗生素的耐药表型。菌株对四环素、克林霉素和氨苄西林的平均耐药率分别为45%、20%和16%，4株菌株对克林霉素的最低抑菌浓度≥128μg/mL。研究表明水生动物中产气荚膜梭菌的分离率较高，且首次从煮熟的蛤仔中分离到，同时也首次检测到cpe和netB毒素基因。cpe基因编码的毒素可导致人类食物中毒，因此本研究的发现对食品安全具有一定的指导意义。水生来源的耐药产气荚膜梭菌可能源于陆地环境中的传播或水产养殖环境的抗生素污染，具有公共卫生意义。
