Investigation of Some Bacterial Zoonotic Diseases of Fish in Khartoum State-Sudan

Abstract

Freshwater fish play a major role in feeding of people near to Nile River specially in Sudan.This study was conducted to investigate some bacterial zoonotic diseases of fish from November 2019 to December 2020 in Khartoum state.A total of 50 fish were examined at Almawrada fish market, Omdurman locality, Khartoum state. One hundred and fifty tissue samples (gills,livers and kidneys) were taken from 50 different breeds of fish were 19 Nile tilapia(Oreochromis niloticus),18 Synodontis (Synodontis schall), 3 Nile puffer(Tetraodon lineatus),4 Bagrus catfishes (Bagrus bayad) and 6 Nile Perch(Lates niloticus). Fish postmortem,bacteriological diagnosis and conventional PCR were applied for confirmation.The common lesions observed externally were darkness of the skin, hemorrhage in the fins base, eyes and different parts of the body, abdominal distention, congested gills and increasing in mucous secretion. The postmortem findings showed white serous fluid in the abdominal cavity and sometimes tinged with blood and pale or congested livers and kidney. Three swab samples obtained from each fish from gills, livers and kidneys.The bacteriological isolation and identification samples revealed that the prevalence of bacterial pathogens among naturally infected freshwater fishes were Streptococcus iniae (21;14%),Staphylococcus aureus(47;31.3%), Salmonella spp(44;29.3%), Escherichia coli(44; 29.3%) and Pseudomonas spp(17; 11.3%).The results of risk factors shown that there was age of fish more associated with E.coli infection.When PCR was used obvious clear single band was appeared for E.coli.In conclusion the bacteria identified in this study are considered as zoonotic bacteria of significant economic important .Fish contamination from the surrounding of young fish are more susceptible to infection by E.coli and salmonella species.PCR is rapid and realistic tool for diagnosis of fish infection.