Studies on streptococcal infections among cultured fresh water fishes with special reference to its diagnosis by polymerase chain reaction test
Abstract: A total number of 1200 naturally infected fishes (600 Oreochromis niloticus and 600 Clarias gariepinus), were subjected to clinical, post-mortem and bacteriological examinations. The bacteriological examination revealed the presence of 268 Streptococcus species isolates. The prevalence was 22.33 % among the examined fishes.
Streptococcal infection for O. niloticus and C. garepinus was highest in summer and lowest in winter. Streptococcus spp. infection rate for O. niloticus was highest in Kafr El-Sheikh and lowest in Sharkia, while, for C. gariepinus was highest in Kafr El-Sheikh and lowest Domyata governorates in Egypt.
Bacteriological examination revealed the isolation of 268 different bacterial isolates. Isolates were isolated from kidney, liver, ascetic fluid, intestine and spleen. The bacterial isolates were identified as 5 species Streptococcus faecium (42.9%), Streptococcus faecalis (29.48%), Streptococcus sp1. (11.57%), Streptococcus sp2 (8.96%) and Streptococcus sp3 (7.09%). Antibacterial sensitivity testes revealed that there were differences between strains in the sensitivity against different antibacterial discs. Experimental injection of fish revealed that there is no difference in susceptibility between normal tilapia and monosex tilapia.
Analysis of proteins of the isolated Streptococcus spp. revealed presence of common characteristics bands (18 and 35KD) which characteristics to Streptococcus spp. and Enterococcus faecalis. The tree for RAPD-PCR that resulted from cluster analysis noticed that there were two main groups (standard Streptococcus faecalis and Streptococcus faecalis) as one group, and Streptococcus sp.2 and Streptococcus sp.3 as a second group, while the Streptococcus faecium branched to one subgroup from the Streptococcus sp.2 and Streptococcus sp3 group. But the Streptococcus sp.1 presented as out-group.
RAPD-PCR analysis revealed that seven primer out of ten primers yielded number of polymorphic and share bands and three primers failed to give shared bands. 65 DNA bands were detected, 11 shard bands.
URL
Publication year 2006
Availability location المعمل المركزى لبحوث الثروة السمكية
Availability number
Organization Name
City فيراكروز
serial title 7th International Symposium on Tilapia in Aquaculture. September 6-8, 2006. Veracruz, Mexico
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Author(s) from ARC
External authors (outside ARC)
    حلمى أحمد تركى كلية الطب البيطرى جامعة الإسكندرية
    مجدى خليل سليمان كلية الطب البيطرى جامعة الإسكندرية
Agris Categories Animal diseasesFisheries production
AGROVOC
TERMS		 Analytical methods. Clarias gariepinus. Oreochromis niloticus. PCR. Streptococcus.
Publication Type Conference/Workshop
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