Hemolytic and elastolytic activities influenced by iron in Plesiomonas shigelloides

The aim of this study was to determine the presence of hemolytic and elasto lytic enzymes in several strains of Plesiomonas shigelloides in relation to the availability of iron in culture media. Hemolytic activity and elastoly tic activity were detected in strains of P. shigelloides and were enhanced when the strains were grown in an iron-depleted medium and lost after therm al treatment at 100 degrees C for 10 min. Also, elastolytic activity was in activated by phenylmethyl sulfonyl fluoride, an inhibitor of serine proteas es. Hemolytic activity was detected extracellularly in cell-free supernatan ts, whereas elastin degradation activity was cell associated. Both activiti es may be related to the virulence of P. shigelloides.