Mwega Elisa, Colquhoun Duncan J, Tuntufye Huruma, Mdegela Robinson, Mutoloki Stephen, Evensen Øystein, Wasteson Yngvild
College of Veterinary and Medical Sciences, Sokoine University of Agriculture, Post Office Box 3019, Morogoro, Tanzania.
Norwegian Veterinary Institute, Post Office Box 750, Sentrum, N-0106, Oslo, Norway.
J Aquat Anim Health. 2019 Mar;31(1):23-30. doi: 10.1002/aah.10048. Epub 2019 Jan 9.
The present study was conducted to explore the occurrence of Flavobacteriaceae in wild Nile Tilapia Oreochromis niloticus (n = 108) collected from Lake Victoria and farmed Nile Tilapia (n = 187) collected from 12 ponds in the Morogoro region of Tanzania. The size of the ponds surveyed ranged from 130 to 150 m . Pond parameters and fish morphometric data were recorded during sampling. In total, 67 Flavobacterium-like isolates (n = 44 from farmed fish; n = 23 from wild fish) were identified on the basis of colony morphology and biochemical tests. Sequences from the 16S ribosomal RNA (rRNA) gene revealed that all 67 isolates belonged to the genera Flavobacterium and Chryseobacterium. Based on 16S rRNA nucleotide identity, 26 isolates showed high similarity with C. indologenes (99-100% identity), 16 showed similarity to C. joostei (98-99.9%), and 17 were similar to diverse species of Chryseobacterium (97-99%). Three isolates were similar to F. aquatile and three were similar to F. indicum, with 99-100% nucleotide identity in both cases, and two isolates were similar to F. oryzae (99-100% identity). The findings obtained in this study provide a baseline for future studies and contribute to an understanding of the threats presented by the aquatic Flavobacteriaceae reservoir toward the development of healthy fish farming in Tanzania. Such knowledge is vital for the development of a sustainable aquaculture industry in Tanzania that will contribute to increased food security.
本研究旨在探究从维多利亚湖采集的野生尼罗罗非鱼（Oreochromis niloticus，n = 108）以及从坦桑尼亚莫罗戈罗地区12个池塘采集的养殖尼罗罗非鱼（n = 187）中黄杆菌科细菌的存在情况。所调查池塘的面积在130至150平方米之间。在采样过程中记录了池塘参数和鱼类形态测量数据。根据菌落形态和生化试验，共鉴定出67株类黄杆菌分离株（44株来自养殖鱼类；23株来自野生鱼类）。16S核糖体RNA（rRNA）基因序列显示，所有67株分离株均属于黄杆菌属和金黄杆菌属。基于16S rRNA核苷酸同一性，26株分离株与吲哚金黄杆菌高度相似（同一性为99 - 100%），16株与约氏金黄杆菌相似（98 - 99.9%），17株与金黄杆菌属的不同物种相似（97 - 99%）。3株分离株与水生黄杆菌相似，3株与印度黄杆菌相似，两种情况下核苷酸同一性均为99 - 100%，2株分离株与米黄杆菌相似（99 - 100%同一性）。本研究所得结果为未来研究提供了基线，并有助于了解水生黄杆菌科细菌库对坦桑尼亚健康养鱼业发展构成的威胁。此类知识对于坦桑尼亚可持续水产养殖业的发展至关重要，有助于提高粮食安全。
