摘要

    目前，智利红水currently的养殖被认为是智利水产养殖的优先事项，但是幼虫低的成活率促使人们需要持续使用抗菌素。这项研究的主要目的是评估活饲料作为商业细菌在G. chilensis中的作用。在幼虫生长期间收集用作活饲料的轮虫和卤虫培养物样品，并使用散布板法进行可培养细菌计数。轮虫和卤虫培养物表现出高水平的抗性细菌（分别为8.03×104至1.79×107 CFU / g和1.47×106至3.50×108 CFU / g）。使用16S rRNA基因序列分析，六十五种氟苯尼考耐药菌株被鉴定为弧菌（81.5％）和假单胞菌（15.4％）。耐药菌株显示出对链霉素（93.8％），土霉素（89.2％），三苯甲唑（84.6％）和卡那霉素（73.8％）的高耐药性发生率。高比例的分离株（76.9％）带有氟苯尼考耐药编码基因floR和fexA，以及质粒DNA（75.0％）。活饲料中多重耐药细菌的高流行增加了养殖鱼幼体中耐药菌群的发生率，因此，对活饲料养殖采取适当的监测和管理策略似乎是防止鱼幼体养殖未来治疗失败的首要任务。

    The culture of red cusk eel Genypterus chilensis is currently considered a priority for Chilean aquaculture but low larval survival rates have prompted the need for the continuous use of antibacterials. The main aim of this study was to evaluate the role of live feed as a source of antibacterial-resistant bacteria in a commercial culture of G. chilensis. Samples of rotifer and Artemia cultures used as live feed were collected during the larval growth period and culturable bacterial counts were performed using a spread plate method. Rotifer and Artemia cultures exhibited high levels of resistant bacteria (8.03 × 104 to 1.79 × 107 CFU/g and 1.47 × 106 to 3.50 × 108 CFU/g, respectively). Sixty-five florfenicol-resistant isolates were identified as Vibrio (81.5%) and Pseudoalteromonas (15.4%) using 16S rRNA gene sequence analysis. A high incidence of resistance to streptomycin (93.8%), oxytetracycline (89.2%), co-trimoxazole (84.6%), and kanamycin (73.8%) was exhibited by resistant isolates. A high proportion of isolates (76.9%) carried the florfenicol-resistance encoding genes floR and fexA, as well as plasmid DNA (75.0%). The high prevalence of multiresistant bacteria in live feed increases the incidence of the resistant microbiota in reared fish larvae, thus proper monitoring and management strategies for live feed cultures appear to be a priority for preventing future therapy failures in fish larval cultures. 

    https://www.mdpi.com/2076-2615/10/3/505