Hard-shelled mussel (Mytilus coruscus) is a popular seafood in South Korea because of its delicacy and high nutritional value. Our study aimed to identify antimicrobial and heavy-metal resistance determinants in Aeromonas isolates from marketed hard-shelled mussel in South Korea. A total of 33 Aeromonas species were isolated, and antimicrobial disk diffusion test was done to observe antimicrobial resistance patterns. In addition, broth microdilution test was performed to determine resistance to heavy-metals. PCR amplification was done to detect resistance genes. High resistance to amoxicillin (100.0%), ampicillin (93.9%), rifampicin (78.8%), and cephalothin (48.5%) was observed where least resistance to other antimicrobials was also detected. In addition, the isolates showed high resistance to cadmium (Cd) (57.6%), and 42.4% and 27.3% were resistant to chromium (Cr) and copper (Cu). The occurrence of antimicrobial resistance genes, such as blaTEM, blaSHV, blaCTX-M, tetB, tetE, and intI1 genes, was observed in 9 (27.3%), 8 (24.2%), 8 (24.2%), 6 (18.2%), 5 (15.2%), and 9 (27.3%) isolates, respectively. Also, heavy-metal resistance genes, czcA, copA, and merA were detected in 17 (51.5%), 11 (33.3%), and 7 (21.2%) of the isolates, respectively. The results suggest that mussels are a reservoir of multidrug and heavy-metal-resistant Aeromonas spp.

中文翻译：

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气单胞菌中抗菌和重金属抗性基因的检测。从硬壳贻贝 (Mytilus Coruscus) 中分离

硬壳贻贝（Mytilus coruscus）因其美味和高营养价值而在韩国很受欢迎。我们的研究旨在确定从韩国销售的硬壳贻贝中分离出的气单胞菌中的抗菌素和重金属耐药性决定因素。共 33 个气单胞菌分离物种，并进行抗菌盘扩散试验以观察抗菌素耐药性模式。此外，进行肉汤微量稀释试验以确定对重金属的抗性。进行PCR扩增以检测抗性基因。观察到对阿莫西林 (100.0%)、氨苄青霉素 (93.9%)、利福平 (78.8%) 和头孢菌素 (48.5%) 的高耐药性，而对其他抗菌药物的耐药性最低。此外，分离株对镉（Cd）具有较高的抗性（57.6%），对铬（Cr）和铜（Cu）的抗性分别为42.4%和27.3%。blaTEM、blaSHV、blaCTX-M、tetB、tetE和intI1等抗菌素耐药基因的发生基因，分别在 9 个（27.3%）、8 个（24.2%）、8 个（24.2%）、6 个（18.2%）、5 个（15.2%）和 9 个（27.3%）分离株中观察到。此外，重金属抗性基因czcA、copA和merA分别在 17 个（51.5%）、11 个（33.3%）和 7 个（21.2%）分离物中检测到。结果表明，贻贝是多药和耐重金属气单胞菌属的宿主。