Susceptibility response of Claria gariepinus to infection with Pseudomonas aeruginosa and prophylactic treatment with chloramphenicol

Abstract

Susceptibility responses of cat fish – Clarias gariepinus to infection with Pseudomonas aeruginosa vis-à-vis treatment with chloramphenicol were investigated in the present study.  Thirty healthy and physically active fishes weighing between 200-350g sourced from Challawa Gorge Dam, Karaye, Kano State were used for the study.  These were divided into three aquarium tanks A, B, C (ten in each case).  Fishes in A were infected with 1.0ml (about 1.2 x 10⁶cfu/ml) of Pseudomonas aeruginosa pyrenterally through linea alba by ventral medial furrow.  This was followed immediately with 0.5ml chloramphenicol (MIC 125µg/ml) solution.  The dose was repeated twelve hourly for five days.  Similarly, fishes in B were infected but no treatment with chloramphenicol.  Fishes in C were injected with ringers solution only and these served as the control.  At the end of the 21 day experimental period, a 70% mortality was observed in the infected and anti-microbially treated fishes of tank A in addition to generalized symptoms of poor feeding, sluggishness (loss of vigour) and skin depigmentation.  However, there was 90.5% mortality in the infected but untreated fishes of tank B.  In the control group, 10% mortality was observed which may be due to short comings in the husbandry techniques employed.  It could be concluded therefore, that Pseudomonas aeruginosa is highly pathogenic to Clarias gariepinus and the bacteria showed lower sensitivity to one of the drugs of choice-chloramphenicol.  It is thus recommended that anti-microbial should be screened against this infective bacteria in order to improve on the quality and yield of fish production.