High levels of hydrolytic enzymes secreted by Candida albicans isolates involved in respiratory infections

Differences in production of two putative virulence factors of Candida albicans, phospholipase and proteinase, were determined for a large panel of clinical C. albicans isolates (n = 186) obtained from the European SENTRY programme. Seventy-two per cent of isolates produced detectable amounts of phospholipase and 95% of isolates produced detectable amounts of proteinase. There was no clear correlation between the results of the phospholipase and proteinase assays and the geographical distribution of the isolates. However, isolates that originated from respiratory infections produced significantly higher amounts of phospholipase than isolates obtained from blood, the urinary tract or wounds/skin/soft tissue and also appeared to produce more proteinase. These virulent isolates involved in respiratory infections may originate from the oral cavity. Whether these results are caused by selection for these highly virulent isolates remains to be resolved.