BACKGROUND: Tilapia, Oreochromis niloticus, is an omnivorous and important breeding species in the world. Over the recent years, tilapia breeding has begun in Iran. In aquaculture, it is very important to regulate a balanced diet in terms of nutrients needed for growth, which would be also economically appropriate.OBJECTIVES: The main objective of this study was to investigate the effect of substituting chicken waste powder in the diet of fish at levels of 0, 25, 50, 75, and 100 % on the tissue structure of different parts of the intestine of Nile tilapia.METHODS: 75 fish (three frequency per treatment) were fed with chicken waste powder instead of fish meal in their diet for eight weeks at 0, 25, 50, 75, and 100 % levels. At the end of the treatment, separate samples were taken from the initial, middle, and end parts of the intestine. After passing the usual histological steps, the slides were assessed by hematoxylin-eosin staining and TUNEL immunohistochemistry technique.RESULTS: In histometric studies, the highest villi height, thickness, muscle layer, and number of goblet cells were reported in the control group and the lowest in the 100 % group. In immunohistochemical studies, the number of apoptotic cells in groups 75 and 100 % was higher than that in the other groups.CONCLUSIONS: According to the results of the present study, it could be suggested that the replacement of chicken waste powder instead of a fish meal up to 50 % for indigo tilapia is tolerable. However, higher levels of chicken waste powder will reduce absorption, and acceptance of food and have adverse effects on growth.

This study was carried out to evaluate the bacteriological status of fresh Tilapia nilotica, fresh Clarias lazera, frozen Mackerel and smoked Herring fish marketed in Beni-Suef City. The collected samples were examined for total bacterial count, coli form (MPN), faecal coli forms (MPN), E. coli (MPN), Staphylococcus aureus count, total proteolytic count, total lipolytic count, Aeromonas count and Pseudomonas count, as well as the isolation of E. coli, Staphylococcus aureus, Aeromonas hydrophila, Pseudomonas aeruginosa, Yersinia enterocolitica and Listeria monocytogenes. Most of the examined samples were within the permissible limits recommended by EOS and ICMSF, few samples of fresh Clarias lazera exceeded the recommended limits. The economic importance and public health significance of the isolated organisms were discussed.

Objectives: Streptococcus agalactiae is a zoonotic human and animal pathogen that causes global economic losses in aquaculture and fatal outcomes in Tilapia. This study aimed to identify S. agalactiae isolated from different fish sources intended for human consumption phenotypically and genotypically and to characterize the virulence-associated genes fbsA (fibrinogen-binding protein FbsA), cfb (CAMP factor), and pbp1A/ponA (penicillin-binding protein 1A). Materials and Methods: Three hundred Nile Tilapia fish (Oreochromis niloticus) were collected from different farms and retail shops in Dakahlia and Damietta, Egypt, during the summer of 2020. The samples were examined using routine phenotypic methods, then characterized using polymerase chain reaction (PCR) targeting S. agalactiae-specific dltS gene. All S. agalactiae isolates were examined for the susceptibility to ten antimicrobial agents by the disc diffusion method. The virulence-associated genes (fbsA, cfb, and pbp1A/ponA) were characterized using multiplex-PCR. Results: Streptococcus agalactiae was detected in 7% (n = 21/300) samples. The isolates showed high resistance against ampicillin and erythromycin (20/21; 95%) for each. The most predominant antibiotypes through isolates were P, CN, SXT, CRO, TE, CTX, E, AMP, at 10.5% for each antibiotype. A total of 19 (90.5%) of S. agalactiae isolates showed multi-drug resistance (MDR), and those were recovered from market Tilapia fish. The virulence-associated genes (fbsA, cfb, and pbp1A/ ponA) were identified in the S. agalactiae as 100%, 76%, and 52%, respectively. Conclusions: The MDR S. agalactiae detected in raw Tilapia fish pose a significant health hazard to consumers due to their zoonotic characteristics. [J Adv Vet Anim Res 2022; 9(1.000): 95-103]

Objectives: Streptococcus agalactiae is a zoonotic human and animal pathogen that causes global economic losses in aquaculture and fatal outcomes in Tilapia. This study aimed to identify S. agalactiae isolated from different fish sources intended for human consumption phenotypically and genotypically and to characterize the virulence-associated genes fbsA (fibrinogen-binding protein FbsA), cfb (CAMP factor), and pbp1A/ponA (penicillin-binding protein 1A). Materials and Methods: Three hundred Nile Tilapia fish (Oreochromis niloticus) were collected from different farms and retail shops in Dakahlia and Damietta, Egypt, during the summer of 2020. The samples were examined using routine phenotypic methods, then characterized using polymerase chain reaction (PCR) targeting S. agalactiae-specific dltS gene. All S. agalactiae isolates were examined for the susceptibility to ten antimicrobial agents by the disc diffusion method. The virulence-associated genes (fbsA, cfb, and pbp1A/ponA) were characterized using multiplex-PCR. Results: Streptococcus agalactiae was detected in 7% (n = 21/300) samples. The isolates showed high resistance against ampicillin and erythromycin (20/21; 95%) for each. The most predominant antibiotypes through isolates were P, CN, SXT, CRO, TE, CTX, E, AMP, at 10.5% for each antibiotype. A total of 19 (90.5%) of S. agalactiae isolates showed multi-drug resistance (MDR), and those were recovered from market Tilapia fish. The virulence-associated genes (fbsA, cfb, and pbp1A/ ponA) were identified in the S. agalactiae as 100%, 76%, and 52%, respectively. Conclusions: The MDR S. agalactiae detected in raw Tilapia fish pose a significant health hazard to consumers due to their zoonotic characteristics. [J Adv Vet Anim Res 2022; 9(1.000): 95-103]