Phospholipases C from Pseudomonas aeruginosa and Bacillus cereus isolates, chromosome-mediated enzymes with roles in virulence

摘要

Phospholipases C (PLCs) from Pseudomonas aeruginosa D183 and Bacillus cereus D101, 2 clinical isolates from 2 pus specimens, were partially purified by ammonium sulfate precipitation followed by dialysis and used to study the possible role of PLC in the virulence of the isolates. Partially purified PLC from both isolates induced lysis of Vero cells in the presence and absence of the producing bacterial cells. Noncytolytic dilutions of the partially purified PLC from Pseudomonas aeruginosa increased adherence of the producing cells to Vero cells but did not affect internalization. However, Bacillus cereus cells neither adhered to nor were internalized within the Vero cells in the presence or absence of noncytolytic dilutions of partially purified PLC from the isolate. Both PLC preparations were hemolytic to human red blood cells but did not induce human platelet aggregation. Thus, we can conclude that PLCs from Pseudomonas aeruginosa and Bacillus cereus are important virulence factors. PLC production by the 2 isolates was found to be chromosomal-mediated rather than plasmid-mediated.