Flavobacterium columnare is a significant fish pathogen of economic importance. Although, many studies have been done on Flavobacterium columnare in other countries, little or no investigation has been carried out in Nigeria especially on Clarias gariepinus associated Flavobacterium columnare infections. This study was undertaken to investigate the occurrence of Flavobacterium columnare in pond-cultured Clarias gariepinus and to determine their antibiotics susceptibility and resistance patterns. Swabs were aseptically taken from the kidney, liver, gills, skin and intestine of the affected fish samples, and analyzed microbiologically. After series of biochemical test, 58 out of 75 bacterial isolates recovered were presumptively identified as Flavobacterium columnare. Confirmatory identification of the isolates was carried out with previously described primers using multiplex PCR. Standard Kirby-Bauer disc diffusion method was used for antibiotics susceptibility test. Flavobacterium columnare isolates were 100% resistant to Streptomycin, Oxytetracycline, Chloranphenicol, Pefloxacin, Ofloxacin and 90, 70 and 60% resistant to Gentamycin, Amoxycillin and Clindamycin respectively. However, all the isolates were 100% susceptible to Ciprofloxacin and Cotrimoxazole only. The results revealed multiple drug resistance of the isolates to the antibiotics tested as the isolates were resistant to eight out of ten antibiotics used in this study. There are fewer studies on antibiotic resistance in Flavobacterium columnare from aquaculture enterprises and this study provides further support to the view that there is a potential risk of transfer of resistant bacteria and their genes to human pathogen through the food chain. Although, in Nigeria there is no antibiotic product registered for aquaculture usage, yet fish farmers use them off-label for bacterial diseases prevention.
Keywords: Flavobacterium columnare, Antibiotic Resistance, Clarias gariepinus, Multiplex PCR.
Bernardet, J.F. and Bowman, J.P. (2006). The genus Flavobacterium. In: The prokaryotes: A handbook on the biology of bacteria: Volume 7: Proteobacteria: Delta and Epsilon Subclasses. Deeply Rooting Bacteria. Springer Science + Business Media, LLC. New York.
Bullock, G.L. (1990). Bacterial gill disease of freshwater fishes. Fish disease leaflet 84, Fish and Wildlife Service, Washington, DC, U.S.
Chalkoo, S R., Qureshi, T.A., Najar, A.M. and Shafi, A. (2007). Bacterial Diseases of Fishes of Wular Lake. Fishing Chimes 26, 41–46.
Clifford, E.S. (2011). Bacterial Coldwater disease of fishes caused by Flavobacterium psychrophilum. Journal of Advanced Research 2:97-108. Clinical Laboratory Standards institute (2016). Performance Standards for Antimicrobial Susceptibility Testing; Twenty six Informational supplement M100S-S26 2016; 36 (1).
Darwish, A.M., Ismaiel, A.A., Newton, J.C. and Tang, J. (2004). Identification of Flavobacterium columnare by a species-specific polymerase chain reaction and renaming of ATCC 43622 strain to Flavobacterium johnsoniae. Molecular and Cellular Probes 18: 421-427.
Decostere, A., Haesebrouck, F., Chalier, G. and Ducatelle, R. (1999). The association of Flavobacterium columnare strains of high and low virulence with gill tissue of black mollies (Poecilia sphenops). Veterinary 67:287 – 298.
Dinesh, K., Yogendra, P., Singh, A.K. and Abubakar, A. (2012). Columnaris Disease and its drug resistance in cultured exotic African catfish Clarias gariepinus in India. Biochemical and Cellular Archives 12(2):415-420.
Ferguson, H.W., Ostland, V.E., Byrne, P. and Lumsden, J.S. (1991). Experimental production of bacterial gill disease in trout by horizontal transmission and by bath challenge. Journal of Aquatic Animal Health 3:118-123.
Ogbonne, F.C., Ukazu, E.R. and Egbe, F.C. (2018). Antibiotics Resistance Pattern and Plasmid Profiling of Edwardsiella tarda Isolated from Heterobranchus longifilis. Journal of Biosciences and Medicines 6:95-105.
Panangala, V.S., Shoemaker, C.A. and Klesius, P.H. (2007). TaqMan real-time polymerase chain reaction assay for rapid detection of Flavobacterium columnare. Aquaculture Research 38: 508-517.
Patra, A., Sudeshna, S., Sayani, B., Harresh, A., Debadyuti, B. and Thangapalam J.A. (2016). Rapid Detection of Flavobacterium columnare Infection in Fish by Species-specific Polymerase Chain Reaction. Journal of Aquaculture Research and Development 7(9):2-5.
Robert, S.B., Murray, E.G.D. and Nathan, R.S. (1962). Bergey's manual of determinative bacteriology (7th ed.). Baltimore, Md.: Williams and Wilkins, 1094 pp.
Tiirola, M., Valtonen E.T., Rintamaki-Kinnunen, P., Kulomaa M.S. (2002). Diagnosis of ﬂavobacteriosis by direct amplification of rRNA genes. Diseases of Aquatic Organisms 51:93-100.
Triyanto, K. A. and Wakabayashi, H. (1999). The use of PCR targeted 16S rDNA for identification of genomovars of Flavobacterium columnare. Fish Pathology 34: 217-218.
Welker, T.L., Shoemaker, C.A., Arias, C.R. and Klesius, P.H. (2005). Transmission and detection of Flavobacterium columnare in channel catfish Ictalurus punctatus. Diseases of Aquatic Organisms 63: 129-138.