Comparative study of the biotype, hemolysin-producing capability and antibiogram of the aquatic and the clinical strains of Aeromonas hydrophila.
One hundred and seventy-two Aeromonas hydrophila strains were isolated from aquatic hosts including fish, turtle, frogs, shellfish and water itself. The aquatic organisms were compared with 45 clinical strains with regard to biotype, hemolysin, and antibiogram. The carrier rate of A. hydrophila in the aquatic environment was 61.7%. Of the aquatic strains 51% were hemolysin producers, equivalent to a capability for producing enterotoxin. The hemolysin-producing capability of aquatic strains was not significantly different from that of the clinical strains. The main code numbers or biotypes of aquatic strains were 3265 (29.4%), 3065 (17.5%), 7065 (9.6%), 7265, 3225 (each 8.5%). The main code number or biotypes of clinical strains were 3265 (36.1%), 3065 (9.8%), 7261 (6.6%), 2265, 3261 and 6241 (each 4.9%). Analysis of the antibiotic susceptibility pattern of both aquatic and clinical A. hydrophila strains using the microbroth dilution method showed that there is no significant difference in antibiotic susceptibility. Most aquatic and clinical strains were highly susceptible to tobramycin, gentamicin, amikacin, cefuroxime, piperacillin, cefotaxime and cefoperazone. Most strains of aquatic A. hydrophila were highly susceptible to cefamandole and chloramphenicol; however, clinical strains were only moderately susceptible to the same drugs. Most aquatic and clinical strains were highly resistant to ampicillin, and moderately resistant to sulbenicillin. Clinical strains were moderately resistant to cephapirin; however, aquatic strains were moderately susceptible to cephapirin. Based on the above findings, we may considered aquatic environment be, at least partially, the source of clinical strains. Furthermore, biotypes of aquatic A. hydrophila do not correspond to antibiogram or hemolysin-producing patterns.
D000333:Aeromonas / Q000145:classification* / Q000187:drug effects / Q000378:metabolism; D000900:Anti-Bacterial Agents / Q000494:pharmacology*; D006460:Hemolysin Proteins / Q000096:biosynthesis*; D006801:Humans; D008826:Microbial Sensitivity Tests; D014871:Water Microbiology
D000900:Anti-Bacterial Agents; D006460:Hemolysin Proteins