Pereira Carla, Salvador Sara, Arrojado Cátia, Silva Yolanda, Santos Ana L, Cunha Angela, Gomes Newton C M, Almeida Adelaide
CESAM and Department of Biology, University of Aveiro, Campus Universitário de Santiago, 3810-193 Aveiro, Portugal.
J Environ Monit. 2011 Apr;13(4):1053-8. doi: 10.1039/c0em00434k. Epub 2011 Feb 23.
The increasing problem of antibiotic resistance in common pathogenic bacteria and the concern about the spreading of antibiotics in the environment bring the need to find new methods to control fish pathogens. Phage therapy represents a potential alternative to antibiotics, but its use in aquaculture requires a detailed understanding of bacterial communities, namely of fish pathogenic bacteria. Therefore, in this study the seasonal dynamics of the overall bacterial communities, microbiological water quality and disease-causing bacteria were followed in a marine aquaculture system of Ria de Aveiro (Portugal). Analysis of the bacterial diversity of the water samples by denaturing gradient gel electrophoresis (DGGE) of 16S rRNA gene fragments indicates that the bacterial community structure varied seasonally, showing a higher complexity during the warm season. The diversity of the main fish pathogenic bacteria, assessed by DGGE targeting the Vibrio genus, showed lower seasonal variation, with new dominating populations appearing mainly in the spring. Bacterial indicators, faecal coliforms and enterococci, enumerated by the filter-membrane method, also varied seasonally. The fluorescent in situ hybridization (FISH) results showed that the specific groups of bacteria varied during the study period and that the non-indigenous Enterobactereaceae family was the most abundant group followed by Vibrio and Aeromonas. The seasonal variation detected in terms of density and structure of total and pathogenic bacterial communities demonstrates the need for a careful monitoring of water through the year in order to select the suitable phages to inactivate fish pathogenic bacteria. The spring season seems to be the critical time period when phage therapy should be applied.
常见病原菌中抗生素耐药性问题日益严重，且人们对抗生素在环境中的传播深感担忧，这使得寻找控制鱼类病原菌的新方法成为必要。噬菌体疗法是抗生素的一种潜在替代方法，但其在水产养殖中的应用需要详细了解细菌群落，尤其是鱼类病原菌。因此，在本研究中，我们跟踪了葡萄牙阿威罗河口一个海水养殖系统中整体细菌群落、微生物水质和致病细菌的季节动态。通过对16S rRNA基因片段进行变性梯度凝胶电泳（DGGE）分析水样中的细菌多样性，结果表明细菌群落结构随季节变化，在温暖季节表现出更高的复杂性。通过针对弧菌属的DGGE评估主要鱼类病原菌的多样性，结果显示季节性变化较小，主要在春季出现新的优势种群。采用滤膜法计数的细菌指标——粪大肠菌群和肠球菌——也随季节变化。荧光原位杂交（FISH）结果表明，在研究期间特定细菌群发生了变化，非本土肠杆菌科是最丰富的菌群，其次是弧菌属和气单胞菌属。在总细菌群落和致病细菌群落的密度和结构方面检测到的季节变化表明，需要全年仔细监测水质，以便选择合适的噬菌体来灭活鱼类病原菌。春季似乎是应用噬菌体疗法的关键时期。
