Enzymatic differentiation of Candida parapsilosis from other Candida spp. in a membrane filtration test.
A previously reported enzyme assay on a membrane filter using 4-methylumbelliferyl (4-MU)-N-acetyl-beta-D-galactosaminide, -phosphate and -pyrophosphate as substrates for the differentiation of four Candida spp. has been extended to Candida parapsilosis. The substrate 4-MU-beta-D-glucoside was hydrolyzed by 28 test strains of this species but to a variable extent by seven other yeasts also. For a full enzymatic differentiation of C. parapsilosis from other medical yeasts, a battery of six reactions was required. Of 71 C. parapsilosis positive clinical samples, 4.2% gave a false negative result due to overgrowth by Candida albicans. The present assay is more rapid than a described spectrofluorometric determination of beta-D-glucosidase in a broth, i.e., 9-11 h versus up to >48 h.
Bauters
Tiene G M
TG
Laboratory for Pharmaceutical Microbiology, Department of Pharmaceutical Analysis, Ghent University, Harelbekestraat 72, B-9000 Ghent, Belgium.
Peleman
Renaat
R
Dhont
Marc
M
Vanhaesebrouck
Piet
P
Nelis
Hans J
HJ
D000135:Acid Phosphatase / Q000032:analysis; D002175:Candida / Q000145:classification / Q000201:enzymology / Q000235:genetics / Q000302:isolation & purification*; D002177:Candidiasis / Q000175:diagnosis*; D004796:Clinical Enzyme Tests / Q000379:methods*; D003470:Culture Media; D005374:Filtration; D005696:Galactosidases / Q000032:analysis; D005959:Glucosidases / Q000032:analysis; D006801:Humans; D010539:Permeability; D011755:Pyrophosphatases / Q000032:analysis
D003470:Culture Media; D000135:Acid Phosphatase; D005696:Galactosidases; D005959:Glucosidases; D011755:Pyrophosphatases