Phenotypic characterisation and antibiotic resistance of pseudomonas spp. from seafood and aquaculture farm environment

A total of 115 different Pseudomonas strains isolated from fish, prawn, brackish water and fresh water aquaculture farms environments were characterized based on the biochemical tests, species variations, distribution ratio, and antibiotic resistance profile. 48% Pseudomonas were identified as fluorescent group whereas 52% were falling in the non-fluorescent . Pseudomonas group. Eight different species namely Pseudomonas aeruginosa, Pfluorescens, Pputida , P.alcaligenes, P.pseudoalcaligenes, P.cepacia ( Burkholderia cepacia ) P.maltophilia and P.stutzeri were isolated from seafood, brackish water, and fresh water environments. P.maltophilia and P.stutzeri were not detected from brackish water sources. Biochemical characterization showed diverse mode of nutritional requirements for each species as most commonly used carbon source i.e. glucose was not utilized by P.alcaligenes, Ppseudoalcalignes, and inositol was not utilized by Pseudomonas fluorescent group. All isolates were positive for indole, catalase and oxidase. Starch was not hydrolyzed by Pseudomonas spp. except P.stutzeri . Variable growth pattern was observed at 40C and 420C for each species. Antibioticresistance against nine antibiotics viz. kanamycin, nitrofurantoin, chloramphenicol, oxytetracycline, gentamicin, rifampicin, neomycin, sulphamethizol, and streptomycin was determined. All isolated Pseudomonas spp. were resistant to nitrofurantoin and sulphamethizol. P.maltophilia and P.stutzeri were sensitive to 7 of 9 antibiotics tested.