Chakraborty Nabanita, Das Basanta Kumar, Bera Asit Kumar, Borah Simanku, Mohanty Debasmita, Yadav Anil Kumar, Kumar Jeetendra, Koushlesh Satish Kumar, Chanu Thangjam Nirupada, Panda Soumya Prasad, Vallangi Ravali
Regional Centre, Central Inland Fisheries Research Institute (ICAR), Guwahati 781006, India.
Central Inland Fisheries Research Institute (ICAR), Barrackpore 700120, India.
Life (Basel). 2022 Nov 25;12(12):1979. doi: 10.3390/life12121979.
Aeromonas species exhibit widespread presence in food, poultry, and aquaculture. They are major multi-drug-resistant fish pathogens. This study aims to identify Aeromonas species harbouring virulence genes aerolysin, flagellin, and lipase from diseased fishes of Assam wetlands with association with antibiotic resistance and in vivo pathogenicity. One hundred and thirty-four Aeromonas strains were isolated and thirty representative species identified using genus-specific 16S rRNA gene amplification. A. veronii was most prevalent (53.7%) followed by A. hydrophila (40.2%), A. caviae (4.47%), and A. dhakensis (1.49%). Ninety percent (90%) of strains harboured at least one of the studied virulence genes: aerA (73.3%), lip (46.6%), and flaA (26.6%). The highest multiple antibiotic resistance (MAR) index 0.8 corresponded to A. hydrophila DBTNE1 (MZ723069), containing all the studied genes. The lowest LD50 values (1.6 × 106 CFU/fish) corresponded to isolates having both aerA and lip. β-lactams showed utmost resistance and lowest for aminoglycosides. There was a significant (p < 0.05) Pearson chi-square test of association between the occurrence of virulence and antibiotic resistance. The in silico protein−protein interaction revealed important drug targets, such as σ28 transcription factor, aminoacyl-tRNA synthetase, and diacylglycerol kinase, with significant (p < 0.05) enrichment. This study suggests that fish-isolate Aeromonas strains represent potential threat to aquaculture with subsequent risk of transferring antibiotic resistance to human pathogens.
气单胞菌属在食品、家禽和水产养殖中广泛存在。它们是主要的多重耐药性鱼类病原体。本研究旨在从阿萨姆邦湿地患病鱼类中鉴定携带气溶素、鞭毛蛋白和脂肪酶等毒力基因的气单胞菌属菌株，并研究其与抗生素耐药性及体内致病性的关系。通过属特异性16S rRNA基因扩增，分离出134株气单胞菌菌株，并鉴定出30个代表性菌种。维罗纳气单胞菌最为常见（53.7%），其次是嗜水气单胞菌（40.2%）、豚鼠气单胞菌（4.47%）和达卡气单胞菌（1.49%）。90%的菌株至少携带一种所研究的毒力基因：aerA（73.3%）、lip（46.6%）和flaA（26.6%）。多重抗生素耐药（MAR）指数最高为0.8，对应含有所有研究基因的嗜水气单胞菌DBTNE1（MZ723069）。最低半数致死剂量（LD50）值（1.6×106 CFU/鱼）对应同时含有aerA和lip的分离株。β-内酰胺类抗生素耐药性最强，氨基糖苷类抗生素耐药性最低。毒力的发生与抗生素耐药性之间存在显著的（p<0.05）Pearson卡方关联检验。计算机模拟的蛋白质-蛋白质相互作用揭示了重要的药物靶点，如σ28转录因子、氨酰-tRNA合成酶和二酰基甘油激酶，且具有显著的（p<0.05）富集。本研究表明，鱼类分离的气单胞菌菌株对水产养殖构成潜在威胁，随后有将抗生素耐药性转移至人类病原体的风险。
