HIGH MORTALITY IN CLARIAS GARIEPINUS FRY ASSOCIATED WITH KLEBSIELLA PNEUMONIAE

摘要

Ten fresh carcasses of catfish fry (2 weeks old) were presented along with four water samples for laboratory analysis. Mortality at the catfish hatchery as at the time of submission of samples for laboratory analysis, was above 60% in a batch of approximately 20,000. History of the farm showed that this mortality pattern had been on for several batches of catfish fry. The water samples were subjected to microbial analysis for total coliform and non-coliform counts, Vibrio species and mould counts, using the spread plate method on sterile MacConkey, TCBS, and Sabouraud dextrose agar plates. Water samples were also subjected to chemical analysis for nitrite, ammonia, pH, Mg2+, Ca2+ and total hardness levels, to ascertain their suitability for fish culture. Swabs taken from suspension of pre-disinfected, rinsed and macerated catfish fry, were streaked on sterile Tryptone soy, MacConkey, TCBS and Sabouraud dextrose agar plates. These inoculated plates were incubated aerobically at 37°C for 24 hours. Results of the chemical analysis of water samples showed that values of the parameters determined fell within the recommended levels for catfish culture at the hatchery level. It was however, observed that the water used at the hatchery (sample A) had uncountable level of coliforms (TNTC) per 0.1 ml (lOOul). Organism isolated from catfish fry, grew only on tryptone soy agar and MacConkey plates and was identified as Klebsiella pneumoniae sub sp pneumoniae. It was susceptible to ofloxacin, streptomycin and nitrofurantoin and resistant to tetracycline, amoxicillin, augmentin and cotrimoxazole.