Detection of certain zoonotic pathogens in lined grunter (Pomadasys stridens, Forsskål 1775)

The current thesis study aims to investigate zoonotic microorganisms and microbial biota in striped gurnard (Pomadasys stridens) obtained as discard products from commercial fishermen at Antalya Fishermen's Harbour. For this purpose, the samples were brought to the laboratory. The study included 39 fish samples. In the laboratory, the fish were first measured for length and weight, and their averages were calculated. The fish were then examined externally. A necropsy was performed on the fish. The findings observed in the internal organs after the necropsy were recorded. Both the external and internal organs of the fish were examined for ectoparasites and endoparasites. After necropsy, samples were taken from internal organs such as the liver, spleen, and kidneys of the fish for bacteriological analysis and were inoculated into Nutrient agar plates containing 2.0% NaCl. The inoculated culture media were incubated at 22 ±2 °C for 24 to 72 hours. After incubation, subcultures were prepared from bacterial colonies that developed in the culture media. The subcultures were incubated at 22 ±2 °C for 24 to 48 hours. Gram staining, motility, cytochrome oxidase, and catalase tests were performed on the bacterial strains. In the Polymerase Chain Reaction (PCR) study, the 16S rRNA gene region was amplified, and the bacterial strains were identified. The fish samples weighed an average of 60 g and measured 15.5 cm in length. No ectoparasites or endoparasites were detected in the fish. Based on the bacteriological and PCR results, 10 strains were isolated and identified. These strains are: Pseudomonas sp. (3 strains), Shewanella sp. (1 strain), Shewanella baltica (2 strains), Pseudoalteromonas sp. (2 strains), Pseudoalteromonas distincta (1 strain), Pseudoalteromonas nigrifaciens (1 strain), and Psychrobacter cibarius. The isolation and identification of Psychrobacter species from fish samples in the present study may be significant in terms of their potential to cause disease in commercially fished and economically valuable fish species in the Antalya Gulf, thereby affecting natural production. Therefore, investigating the microbial communities of endemic and Leseppsian species in the Antalya Gulf fishery may be important.