El-Gammal Ghada A, El-Gamal Adel M, Rashed M A, Kassab Amina S, Saif Aly S, Fadl Sabreen E
Kafrelsheikh Lab, Bacteriology Unit, Agricultural Research Center (ARC), Animal Health Research Institute, Giza, Egypt.
Kafrelsheikh Regional Lab, Fish Diseases Unit, Agriculture Research Center (ARC), Animal Health Research Institute, Giza, Egypt.
Sci Rep. 2025 Apr 26;15(1):14658. doi: 10.1038/s41598-025-96914-7.
Pseudomonas aeruginosa (P. aeruginosa) is one of the most common ones that harm fish. P. aeruginosa has been regarded as one of the most significant threats to the fishing industry, which also affects public health. Thus, the present investigation was done in two steps; the first step was to examine the prevalence and the antibiogram of P. aeruginosa among Nile tilapia (Oreochromas niloticus (O. niloticus)) from aquaculture farms in Kafr El-shiekh Governorate with an emphasis on their antibiotic resistance genes (BlaTEM, tetA, and sul1). The second step was to investigate the effect of levamisole as a feed supplement for tilapia fish on growth performance, immunity, serum biochemistry, and the protective effect against artificial infection with the previously isolated in the first step P. aeruginosa strain. One hundred samples were collected from morbid Nile tilapia fish in the first step. The incidence of P. aeruginosa was 14%. Susceptibility of P. aeruginosa isolates to 9 antimicrobial agents showed that about half of P. aeruginosa isolates were multidrug-resistant (MDR) to (5-6) antibiotics. All of the isolates were sensitive to amikacin, ciprofloxacin, and norfloxacin (100%), and half of them were resistant to azithromycin, amoxicillin with clavulanic, tetracycline, and sulfa with trimethoprim. P. aeruginosa isolates were confirmed diagnosed using the 16S rRNA gene, which was detected in 100% of the tested isolates, and was also evaluated for the presence of antibiotic resistance genes (blaTEM, tetA, and sul1), which were 85.7%, 85.7%, and 100%, respectively. In the second step, a 2-month feeding trial was performed on 160 O. niloticus fish with a weight of 56.75 ± 3 g. Fish were randomly distributed into four groups, each at a rate of 10 fish per aquarium in four replicates, and fed on a diet containing 0.0, 500, 750, and 1000 mg levamisole/kg diet. At the end of the feeding trial, fish were challenged by pathogenic P. aeruginosa, which was isolated in the first step. The results of the in vivo trial showed that levamisole safely improved the growth and immunity of Nile tilapia without side effects on liver function.
铜绿假单胞菌是危害鱼类最常见的病菌之一。它被视为对渔业最重要的威胁之一，还会影响公众健康。因此，本研究分两步进行；第一步是检测卡夫尔谢赫省水产养殖场尼罗罗非鱼（尼罗罗非鱼）中铜绿假单胞菌的流行情况和抗菌谱，重点关注其抗生素抗性基因（BlaTEM、tetA和sul1）。第二步是研究左旋咪唑作为罗非鱼饲料添加剂对生长性能、免疫力、血清生化指标的影响，以及对第一步分离出的铜绿假单胞菌菌株人工感染的保护作用。第一步从患病尼罗罗非鱼中采集了100个样本。铜绿假单胞菌的发病率为14%。铜绿假单胞菌分离株对9种抗菌药物的敏感性表明，约一半的铜绿假单胞菌分离株对（5 - 6）种抗生素具有多重耐药性（MDR）。所有分离株对阿米卡星、环丙沙星和诺氟沙星敏感（100%），其中一半对阿奇霉素、阿莫西林克拉维酸、四环素和磺胺甲恶唑甲氧苄啶耐药。铜绿假单胞菌分离株通过16S rRNA基因进行确诊，在100%的测试分离株中均检测到该基因，同时还评估了抗生素抗性基因（blaTEM、tetA和sul1）的存在情况，其比例分别为85.7%、85.7%和100%。在第二步中，对160条体重为56.75±3克的尼罗罗非鱼进行了为期2个月的投喂试验。鱼被随机分为四组，每组以每个水族箱10条鱼的比例进行四个重复，分别投喂含0.0、500、750和1000毫克左旋咪唑/千克饲料的日粮。在投喂试验结束时，用第一步分离出的致病性铜绿假单胞菌对鱼进行攻毒。体内试验结果表明，左旋咪唑能安全地提高尼罗罗非鱼的生长和免疫力，且对肝功能无副作用。
