Investigation Of The Candida Albicans Nosocomial Infection And The Correlation Between The Secreted Acidic Protease And Their Pathogenicity

Objectvie To investigate the characteristics and distribution of the Candida albicans nosocomial infection in Qingdao Hiserve Hospital; To detect the secreted acidic proteinase of the isolated Candida albicans in order to reveal the correlation between the protease and their pathogenicity of Candida albicans.Method1.2196specimens (blood, ascites or chest fluid, sputum, urine, excrement, vaginal secretion and oropharyngeal swab) were collected from patients in Qingdao Hiserve Hospital during2010.1and2011.12. Candida albicans were isolated and identified by the methods of morphologic observation in microscope, growth feature on SDA medium, the CHROagar colors medium as well as API20C AUX in necessary.3groups of pathogeny, suspicion and normal control,which were taken from health crowd were divided according to the clinical diagnosis and laboratory standard. The secreted acidic protease of all the C.candida strains was measured with the BSA (bovine serum albumin) based agar medium. The activity of secreted acidic proteinase was denoted by the Pa value which was calculated by the following formula:Diameter of C. albicans lavn/Diameter of all blank zone, After that the correlation between the activity of secreted acidic protease and the pathogenicity of C. albicans were analysed.Result1.365strains candida were acquried from2196specimens (relevance ratio16.6%),255strains of C. albicans were the highst proportion (69.9%) in all of the365candida; most of them came (174strains,68.2%) from Sputum and followed by urine (38strains,14.9%). The positive rate and Pa value of secreted acidic protease were significantly higher in pathogenic group(100%; Pa=0.63) than that of suspicious group (89%; Pa=0.86)(P<0.01), moreover, both of the pathogenic and suspicious groups are higher than that of the control group (60%; Pa=0.96)(P<0.01)Conclusion C.albicans is the main pathogen in nosocomial fungal infection and it has higest frequence taking place in respiratory tract. The activities of secreted acidic protease were significant difference from different clinical specimens, they were higher in the pathgenic strains.The method of BSA based argar medium is one of the most useful means for pathogenic identification in C. albicans.