Department of Biology, Nigeria
Title: ANTAGONISTIC ACTIVITY OF LACTIC ACID BACTERIA ISOLATED FROM CATFISH AGAINST Salmonella typhi AND Escherichia Coli
In recent years, there has been a growing interest in controlling disease problems through alternative methods since the use of chemotherapeutic agents may lead to occurrence of resistant bacteria. In this study, a total of twenty fresh and dry catfish samples respectively were purchased at three different markets in Ibadan metropolis and were analyzed for enumeration of lactic acid bacteria. The lactic acid bacteria isolates were subjected to various morphological and biochemical tests. Antagonistic activity and antibiotics susceptibility of the isolates was carried out using agar diffusion method. Our results indicate that only 13 isolates out of 55 isolates obtained were heterofermenters, 15 out of the isolates had antagonistic activity against Salmonella typhi ATCC 33458 and Escherichia coli ATCC 35218. Salmonella typhi was more inhibited by the LAB isolates. Only 8 out the LAB isolates were inhibited by the antibiotics of which Ofloxacin had the highest zone of inhibition . The lactic acid bacteria isolated in this study as ldentified by API CHL 50 kit include Lactobacillus plantarum, Lactobacillus acidophilus andLactobacillus pentosus. This study revealed that the lactic acid bacteria from catfish can inhibit the growth of pathogenic bacteria and could be used in aquaculture to control pathogenic organisms.