Department of Veterinary Medicine, Faculty of Veterinary Medicine, University of Ilorin, Ilorin, Nigeria.
Veterinary Teaching Hospital, Ahmadu Bello University, Zaria, Nigeria.
BMC Vet Res. 2024 Jan 6;20(1):16. doi: 10.1186/s12917-023-03860-5.
Aeromonas species are one of the most important etiologies of diseases in fish farms, leading to clinical manifestation and mortality and are associated with public health risks. This study aimed to investigate the prevalence, phenotypic and molecular characteristics of Aeromonas species isolated from farmed Clarias gariepinus using 16 S rRNA sequencing. Additionally, their antibiogram and multiple antibiotic resistance index were determined using a disc diffusion test.
A total of 230 Aeromonas strains were isolated from Clarias gariepinus with 40.9% obtained from diseased fish, and 25% isolated from apparently healthy ones. Five different species including Aeromonas caviae, Aeromonas veronii, Aeromonas hydrophila, Aeromonas dhakensis and Aeromonas enteropelogenes were fully identified and genetically characterized. Based on the available literature, this is the first report of Aeromonas enteropelogenes from the study area. The phylogenetic analysis showed genetic heterogeneity and distance within the species and the reference strains. The multiple resistant Aeromonas species were susceptible to ciprofloxacin, gentamycin, and florfenicol. The Aeromonas species' multiple antibiotic resistance index values varied between 0.20 and 0.80 and were isolated from the farms where antibiotics were intensively used.
The diversity of multidrug-resistant Aeromonas species isolated from fish farms is a major threat to fish production giving us more understanding of epidemiology and the multidrug Aeromonas species with a MAR index of greater than 0.2 were isolated from farms where antibiotic use was widespread. As a result, a considerably increased danger of multiple antibiotic resistance spreading to the fish culture environment may impact aquaculture production. Hence there is a need for appropriate and monitored drug usage.
气单胞菌是鱼类养殖场疾病的最重要病因之一，导致临床症状和死亡率，并与公共健康风险相关。本研究旨在使用 16S rRNA 测序调查从养殖斑点叉尾鮰中分离的气单胞菌的流行率、表型和分子特征。此外，使用圆盘扩散试验确定它们的药敏谱和多重抗生素耐药指数。
从斑点叉尾鮰中分离出 230 株气单胞菌，其中 40.9%来自患病鱼类，25%来自明显健康的鱼类。充分鉴定并遗传特征分析了包括嗜水气单胞菌、维隆气单胞菌、温和气单胞菌、达卡气单胞菌和肠型气单胞菌在内的 5 种不同的物种。根据现有文献，这是首次从研究区域报告肠型气单胞菌。系统发育分析显示种内和参考菌株的遗传异质性和距离。多耐药气单胞菌对环丙沙星、庆大霉素和氟苯尼考敏感。气单胞菌的多重抗生素耐药指数值在 0.20 到 0.80 之间，并且是从抗生素密集使用的养殖场中分离出来的。
从鱼类养殖场分离的多药耐药气单胞菌的多样性对鱼类生产构成重大威胁，使我们对流行病学和 MAR 指数大于 0.2 的多药耐药气单胞菌有了更多的了解，这些细菌是从抗生素广泛使用的养殖场中分离出来的。因此，多重抗生素耐药性向鱼类养殖环境传播的风险可能会显著增加，从而影响水产养殖生产。因此，需要适当和监测药物的使用。
