FIG 4.

Aerolysin and serine protease association with cytotoxic phenotypes. Multiplex PCR was performed on all Aeromonas isolates, and the isolates were grouped into virulence gene profiles based on the presence or absence of aerolysin and serine protease. Cytotoxic activity is represented by dark bars, and noncytotoxicity is represented by white bars. The percent cytotoxicity against HeLa cells for each genotypic pattern was determined by dividing the number of cytotoxic isolates by the total number of isolates. The total numbers of isolates exhibiting the described genotypes are given above the bars. A, aerolysin; S, serine protease.