ISOLATE BACTERIA AND BACTERIOPHAGE FROM SHRIMP POND AND INVESTIGATING THE EFFECTS OF PHAGE COOKTAIL AGAINST Citrobacter meridianamericanus

Abstract

CM1 bacteria were isolated from shrimp pond bottom mud and identified as Citrobacter meridianamericanus. Surveying the host trains of eight isolated phages and eight phage cooktail against host strains such as Salmonella ATCC 49223, Salmonella ATCC 14028 and E. coli ATCC 25922, Citrobacter meridianamericanus observed fBT3 gives soluble stains on host E. coli ATCC 25922 and 6 phages including fBT1, fBT6, fBT7, fBT8, fBT9 and Mix fBT7 + fBT9 give soluble stains on host Citrobacter spp.. Based on that result 5 phages fBT1, fBT5, fBT6, fBT7 and fBT9 were selected to evaluate the influence of phage on the colony population of Citrobacter meridianamericanus bacteria using the spread counting method. Evaluation results showed that all five bacteriophage strains reduced bacterial population with statistical significance and had specific effects on colony morphology. In which, fBT9 has the greatest ability to reduce bacterial density, down to 1.45 log CFU/mL and fBT8 has the lowest bacterial density reduction of 1.16 log CFU/mL. The results showed that the fBT9 line had the best effectiveness in controlling bacteria. Besides, the combination of two phage strains increases the ability to inhibit bacteria and limit the resistance of bacteria to bacteriophages.