Studies on Bacterial Pathogens in Some Marine Fishes in EL-Mansoura, Egypt

Abstract

A total of 200 marine fish of two different species (100 Tilapia zillii and100 Mugil capito) were randomly collected from different markets, during different seasons. Fish subjected to clinical, postmortem and bacteriological studies. The common clinical signs were darkness of the skin, hemorrhage in the fins base, eyes and different parts of the body, abdominal distention, congestion in gills and increasing in mucous secretion. The Post Mortem findings showed white serous fluid in the abdominal cavity and sometimes tinged with blood and pale or congested liver, kidney and spleen. The bacteriological examination, revealed that the prevalence of bacterial pathogens among naturally infected marine fishes were A. hydrophila (52; 39.39%), V. alginolyticus (38; 28.79%), Ps. fluorescens (24; 18.18%), V. cholerae (10; 7.58%) and Ps. aeruginosa (8; 6.06%). The highest prevalence of bacterial infection was during summer (33.33%) followed by spring (24.42%), then autumn (21.97%), while the least prevalence was in the winter season (20.46%). A. hydrophila was highly pathogenic to T. zillii causing 100% mortality followed by V. alginolyticus causing (90%) mortality, then Ps. fluorescens (80%), Ps. aeruginosa (60%) while V. cholerae was non-pathogenic. The results of antibiogram revealed that ciprofloxacin and nalidixic acid were effective against A. hydrophila, while ciprofloxacin and rifampicin were effective against Ps. fluorescens. Ciprofloxacin and amikacin were effective against Ps. aeruginosa. While V. alginolyticus was highly sensitive to ciprofloxacin. High prevalence of pathogenic and resistant bacterial strains among marine fishes in Egypt, requires strict control measures from the responsible authorities.

Molecular Studies on Aeromonas Species Isolated from Freshwater Fishes Collected from Delta Region, Egypt

“…The collected data showed that in some cases, congestion of gills and visceral organs, enlargement of liver, spleen, and kidney and in some cases paleness of liver and intestine were recorded. These results are in agreement with that formerly obtained in many studies (Parvez and Mudarris, 2014;El-Barbary and Hal, 2016;Elsayed et al, 2018;Elsheshtawy et al, 2019). Hemorrhagic septicemia was also reported in other studies in which relationship between stress factors and incidence of disease was revealed.…”

Molecular detection of the most common bacterial pathogens affecting economically important Egyptian Red Sea fishes

“…The necropsied fishes revealed clear signs of septicemia manifested by gills congestion and viscera, enlargement of different internal organs, and some cases exhibited liver paleness and intestine. These findings agree with those previously reported in many studies (Mustafa et al, 2014(Mustafa et al, , 2016Hashem, 2015;Mohamed et al, 2016;Mahmoud et al, 2017;Elsayed et al, 2018;Eissa et al, 2021).…”

Isolation, phenotypic characterization and antibiotic susceptibility of prevalent bacterial pathogens implicating the mortality of cultured Nile tilapia, Oreochromis niloticus

“…Mahmoud et al, (2016) also reported that bacterial isolates distribution in different organs and tissues of the examined fishes were presented mainly in the liver, kidney, and spleen. Ezzat et al, (2018) have reported that the kidney and the liver were the most predominant organs for isolation of bacteria at a rate (37.4%) and (36.3%), respectively followed by spleen (15.9%) and gills (9.85%). Eissa et al, (2016) reported that Aeromonas sobria isolates were isolated with the high prevalence from kidneys 25.3%, liver 23.0%, spleen 19.8% and intestines 15.0% and the lowest prevalence was recorded from gills and skin lesions at rates of 10.3% and 6.35% respectively.…”