The role of a 40-megadalton plasmid in the adherence and hemolytic properties of Aeromonas hydrophila.

Abstract A cured strain of Aeromonas hydrophila , MS-2PC, was examined for phenotypic changes in antibiotic resistance, adherence, and hemolysis. Parental strain MS-2 was resistant to ampicillin, novobiocin, and carbenicillin; MS-2PC, which lacked a 40-MDa plasmid, was also resistant to ampicillin but was sensitive to novobiocin and carbenicillin. The adherence of these isolates to CaCo-2 and HeLa cells was examined. MS-2PC demonstrated greater attachment to both cell lines than did strain MS-2 ( p p p A. hydrophila MS-2.