African catfish (Clarias garipienus) is a major tropical aquaculture species in Africa and most cultivated by fish farmers in Nigeria. The dominance of African catfish for fish farming is attributed to several favourable characteristics such as its ability to tolerate a varying range of environmental conditions, high stocking densities under culture conditions, fast growth rate, acceptability of artificial feed, high fecundity rate, ease of artificial breeding and high market value. However, catfishes are known to harbour bacteria which limit its suitability for human consumption. Hence, this study was conducted to compare the bacterial loads of C. gariepinus from cultured and natural habitats. A total number of twelve live adult (200–799 g) C. gariepinus comprising 3 each were randomly obtained from two cultured habitats (ponds) and two natural habitats (rivers). In the laboratory, the skin and the intestine of the fish were examined for the presence of bacteria using nutrient, mannitol salt and cetrimide agars. Seven bacteria isolates namely, Pseudomonas aeruginosa, Bacillus subtilis, Staphylococcus aureus, Staphylococcus epidermis, Micrococcus luteus, Escherichia coli and Streptococcus spp. were identified from the catfishes using their colonial, morphological and biochemical characteristics. The results showed that the total bacterial loads in cultured habitat (skin, 25.77 × 104cfu/g; intestine, 22.50 × 104cfu/g) were significantly higher than the total bacterial load recorded in natural habitat (skin, 15.94 × 104cfu/g, intestine, 14.23 × 104cfu/g). Specifically, total Staphylococcal loads (skin, 10.40 × 104cfu/g; intestine, 10.77 × 104cfu/g) and Pseudomonad loads (skin, 6.80 × 104cfu/g; intestine, 8.00 × 104cfu/g) were significantly higher in cultured habitat than natural habitat where Staphylococcal loads (skin, 6.66 × 104cfu/g; intestine, 5.50 × 104cfu/g) and Pseudomonad loads (skin, 5.46 × 104cfu/g; intestine, 5.54 × 104cfu/g) were recorded. Generally, it was observed that bacterial loads were higher on the skin compare to intestines of C. gariepinus obtained from both habitats. The study showed that bacterial loads were more in C. gariepinus obtained from cultured habitat compared to those obtained from natural habitat. It is therefore recommended that sanitary conditions under which fish are reared in fish pond should be improved.

中文翻译：

---

评估从养殖和自然栖息地获得的 Clarias gariepinus (Burchell, 1822) 的细菌负荷

非洲鲶鱼（Clarias garipienus）是非洲主要的热带水产养殖品种，由尼日利亚养鱼户养殖最多。非洲鲶鱼在鱼类养殖中的主导地位归因于几个有利的特征，例如它能够耐受各种环境条件，养殖条件下的放养密度高，生长速度快，人工饲料的可接受性，繁殖率高，易于人工饲养。养殖和高市场价值。然而，众所周知，鲶鱼含有细菌，这限制了其对人类食用的适宜性。因此，本研究旨在比较来自培养和自然栖息地的 C. gariepinus 的细菌负荷。总共 12 只活成虫（200–799 g） C. 从两个养殖栖息地（池塘）和两个自然栖息地（河流）中随机获得 3 只 gariepinus。在实验室中，使用营养物、甘露醇盐和西曲霉胺琼脂检查鱼的皮肤和肠道是否存在细菌。七种细菌分离物，即铜绿假单胞菌、枯草芽孢杆菌、金黄色葡萄球菌、表皮葡萄球菌、藤黄微球菌、大肠杆菌和链球菌属。使用它们的群落、形态和生化特征从鲶鱼中鉴定。结果表明，培养生境（皮肤，25.77×104cfu/g；肠，22.50×104cfu/g）的总细菌载量显着高于自然生境（皮肤，15.94×104cfu/g，肠, 14.23 × 104cfu/g)。具体来说，总葡萄球菌负荷（皮肤，10.40 × 104cfu/g；肠，10.77 × 104cfu/g）和假单胞菌负荷（皮肤，6.80 × 104cfu/g；肠，8.00 × 104cfu/g）显着高于养殖栖息地的自然栖息地记录葡萄球菌负荷（皮肤，6.66 × 104cfu/g；肠，5.50 × 104cfu/g）和假单胞菌负荷（皮肤，5.46 × 104cfu/g；肠，5.54 × 104cfu/g）。通常，观察到与从两个栖息地获得的 C. gariepinus 肠道相比，皮肤上的细菌负荷更高。该研究表明，与从自然栖息地获得的细菌相比，从培养栖息地获得的 C. gariepinus 中的细菌负荷更多。因此建议改善鱼塘养殖的卫生条件。77 × 104cfu/g) 和假单胞菌负荷（皮肤，6.80 × 104cfu/g；肠，8.00 × 104cfu/g）显着高于自然栖息地，其中葡萄球菌负荷（皮肤，6.66 × 104cfu/g；肠，50 × 104cfu/g）和假单胞菌负荷（皮肤，5.46 × 104cfu/g；肠道，5.54 × 104cfu/g）。通常，观察到与从两个栖息地获得的 C. gariepinus 肠道相比，皮肤上的细菌负荷更高。该研究表明，与从自然栖息地获得的细菌相比，从培养栖息地获得的 C. gariepinus 中的细菌负荷更多。因此建议改善鱼塘养殖的卫生条件。77 × 104cfu/g) 和假单胞菌负荷（皮肤，6.80 × 104cfu/g；肠，8.00 × 104cfu/g）在葡萄球菌负荷（皮肤，6.66 × 104cfu/g；肠，8.00 × 104cfu/g）的自然栖息地显着高于自然栖息地（皮肤，6.66 × 104cfu/g；肠，50 × 104cfu/g）和假单胞菌负荷（皮肤，5.46 × 104cfu/g；肠道，5.54 × 104cfu/g）。通常，观察到与从两个栖息地获得的 C. gariepinus 肠道相比，皮肤上的细菌负荷更高。该研究表明，与从自然栖息地获得的细菌相比，从培养栖息地获得的 C. gariepinus 中的细菌负荷更多。因此建议改善鱼塘养殖的卫生条件。00 × 104cfu/g) 在培养生境中显着高于自然生境，其中葡萄球菌载荷（皮肤，6.66 × 104cfu/g；肠，5.50 × 104cfu/g）和假单胞菌载荷（皮肤，5.46 × 104cfu/g；4 肠，5 × 104cfu/g)。通常，观察到与从两个栖息地获得的 C. gariepinus 肠道相比，皮肤上的细菌负荷更高。研究表明，与从自然栖息地获得的细菌相比，从培养栖息地获得的 C. gariepinus 中的细菌负荷更多。因此建议改善鱼塘养殖的卫生条件。00 × 104cfu/g) 在培养生境中显着高于自然生境，其中葡萄球菌载荷（皮肤，6.66 × 104cfu/g；肠，5.50 × 104cfu/g）和假单胞菌载荷（皮肤，5.46 × 104cfu/g；4 肠，5 × 104cfu/g)。通常，观察到与从两个栖息地获得的 C. gariepinus 肠道相比，皮肤上的细菌负荷更高。该研究表明，与从自然栖息地获得的细菌相比，从培养栖息地获得的 C. gariepinus 中的细菌负荷更多。因此建议改善鱼塘养殖的卫生条件。据观察，与从两个栖息地获得的 C. gariepinus 的肠道相比，皮肤上的细菌负荷更高。该研究表明，与从自然栖息地获得的细菌相比，从培养栖息地获得的 C. gariepinus 中的细菌负荷更多。因此建议改善鱼塘养殖的卫生条件。据观察，与从两个栖息地获得的 C. gariepinus 的肠道相比，皮肤上的细菌负荷更高。该研究表明，与从自然栖息地获得的细菌相比，从培养栖息地获得的 C. gariepinus 中的细菌负荷更多。因此建议改善鱼塘养殖的卫生条件。