Fattal B, Dotan A, Tchorsh Y, Parpari L, Shuval H I
Schriftenr Ver Wasser Boden Lufthyg. 1988;78:27-38.
Throughout the world, fish thrive in rivers, lakes and seawater polluted with wastewater. Furthermore, in some countries, wastewater-enriched fishponds are used for fish cultivation. One of the major constraints in using wastewater for aquaculture is the possible contamination of the fish by enteric pathogens (bacteria and viruses), which may penetrate and accumulate in fish tissue, and constitute a potential public health hazard, especially in countries in which raw fish are consumed. In order to evaluate the infection of fish cultivated in wastewater, controlled experiments were performed to study the penetration of bacteria and bacteriophage inoculated into water tanks in which the fish were maintained. Twenty to thirty Tilapia hybrids (Sarotherodon aureus x S. niloticus), of 100 gr average weight and some 20 cm long were introduced into a 1 m3 plastic tank, containing about 500 l tap water at a temperature of 20 degrees C. High protein fish feed was added at a rate of about 1% of body weight per day. Four experiments were performed using an inoculum of an E. coli strain resistant to streptomycin and nalidixic acid. One hour after inoculation, bacterial concentration was 10(5)-10(6)/ml tank water. Four experiments were carried out with F2 male-specific bacteriophage 10(3)-10(5)/ml tank water. In each experiment two fish were sacrificed at zero time (prior to introduction of inocula), and 1, 5, 24, 48 and 72 or more hours after inoculation. Water samples were withdrawn at the same intervals. The level of microorganisms was tested in the following tissues: digestive tract, skin, spleen, liver and muscle. E. coli assays were performed using the membrane filtration technique; phages were assayed, using E. coli host cells in a plaque assay. The results of the experiments indicate that notwithstanding the high E. coli concentration in the tank water, its level in the edible tissue (muscle) was low, and in no instance higher than the acceptable standard of 400 cfu/gr (International Commission for Food Specification, 1974). The maximum concentration of F2 phage detected in muscle tissue was 350 pfu/gr. There is no standard for virus concentration in edible tissue.
在世界各地，鱼类在被废水污染的河流、湖泊和海水中大量繁殖。此外，在一些国家，富含废水的鱼塘被用于鱼类养殖。利用废水进行水产养殖的一个主要限制因素是鱼类可能被肠道病原体（细菌和病毒）污染，这些病原体可能会渗透并积聚在鱼的组织中，构成潜在的公共卫生危害，尤其是在食用生鱼的国家。为了评估在废水中养殖的鱼类的感染情况，进行了对照实验，以研究接种到养鱼水箱中的细菌和噬菌体的渗透情况。将20至30条平均体重100克、体长约20厘米的罗非鱼杂交种（奥利亚罗非鱼×尼罗罗非鱼）放入一个1立方米的塑料水箱中，水箱中装有约500升温度为20摄氏度的自来水。以每天约1%体重的比例添加高蛋白鱼饲料。使用对链霉素和萘啶酸耐药的大肠杆菌菌株接种物进行了四项实验。接种一小时后，细菌浓度为10(5)-10(6)/毫升水箱水。用F2雄性特异性噬菌体进行了四项实验，噬菌体浓度为10(3)-10(5)/毫升水箱水。在每个实验中，在零时间（接种前）以及接种后1、5、24、48和72小时或更长时间处死两条鱼。在相同的时间间隔采集水样。在以下组织中检测微生物水平：消化道、皮肤、脾脏、肝脏和肌肉。使用膜过滤技术进行大肠杆菌检测；使用大肠杆菌宿主细胞通过噬菌斑测定法对噬菌体进行检测。实验结果表明，尽管水箱水中大肠杆菌浓度很高，但在可食用组织（肌肉）中的水平很低，且在任何情况下都不高于400 cfu/克的可接受标准（国际食品规格委员会，1974年）。在肌肉组织中检测到的F2噬菌体的最大浓度为350 pfu/克。目前尚无可食用组织中病毒浓度的标准。
