SCREENING OF BACTERIAL PATHOGENS ASSOCIATED WITH DISEASED FRESHWATER ORNAMENTAL FISHES
| dc.contributor.advisor | S.K.GIRISHA | |
| dc.contributor.author | AMIT KUMAR SOREN, | |
| dc.date.accessioned | 2023-12-18T16:40:25Z | |
| dc.date.available | 2023-12-18T16:40:25Z | |
| dc.date.issued | 2021 | |
| dc.description.abstract | Bacterial diseases are the major constraints in each and every fish culture system of ornamental fishery sector. Bacteria are considered as ubiquitous and are always in contact with the fish. Hence the risk of catching a disease is high when the fish falls under stressful conditions. Screening for major pathogenic bacteria associated with ornamental fish diseases will aid in knowing the probable reason for the untimely death in many ornamental cultures and rearing systems. In the present study, 50 isolates of bacteria were screened from 30 freshwater ornamental fish samples. The fishes exhibited clinical signs like exophthalmia, dropsy, erratic movement, dermal ulceration, haemorrhages, etc. The isolates were subjected to series of biochemical tests and polymerase chain reaction (PCR) assay for identifying their respective genus/species. The tests revealed that the isolates were dominated by the Gram-negative bacteria with Aeromonas spp., followed by Citrobacter spp. and Pleiosomonas spp. Virulence factors like haemolysis, gelatinase and starch hydrolysis were performed. Haemolytic assay revealed that 48% of the isolates were α-haemolytic and 26% were β-haemolytic. Amylase and gelatinase activity was present in 46% and 50% of the isolates respectively. Further, selected 4 isolates (positive for all the virulence factors) were used for 16S rRNA sequencing. The obtained sequences indicated the 4 selected isolates as Aeromonas hydrophila (F3), A. veronii (D2), A. sobria (F7) and Citrobacter freundii (G9-1A); two of them were deposited in GenBank [MN594480.1 (A. hydrophila F3) and MN593732.1 (A. veronii D2)]. The phylogenetic tree analysis found that A. hydrophila, A. sobria, A. veronii. and C. freundii were closely related to reference strain of A. hydrophila (FN997612.1), A.sobria (KM516017.1), A.veronii (EU770280.1) and C. freundii EnZ-4 (MN220573.1) respectively. The antibiotic susceptibility test of the 4 isolates reveal | |
| dc.identifier.uri | https://krishikosh.egranth.ac.in/handle/1/5810203777 | |
| dc.publisher | KARNATAKA VETERINARY, ANIMAL & FISHERIES SCIENCES UNIVERSITY, BIDAR | |
| dc.sub | Fisheries | |
| dc.theme | Fisheries | |
| dc.these.type | M.F.Sc | |
| dc.title | SCREENING OF BACTERIAL PATHOGENS ASSOCIATED WITH DISEASED FRESHWATER ORNAMENTAL FISHES | |
| dc.type | Thesis |