[Isolation of specific DNA probes from Cryptococcus neoformans].
OBJECTIVE
To construct plasmid library and screen specific DNA probes for Cryptococcus neoformans.


METHODS
Serotype A Cryptococcus neoformans was used as the study strain, plasmid pUC18 as vector, and Escherichia coli JM103 as host cell. The plasmid library of cryptococcus neoformans was constructed (pCN). Other pathogenes causing affection diseases which should be distinguished from cryptococcusis clinically, and other fungi similar to Cryptococcus neoformans with physiological and biochemical characteristics were used as a distinguishing system, specific colonies were screened by hibridization in double steps.


RESULTS
The inserts of the library were 280 to 1800 base pairs and 580 base pairs in average length. Repeated sequence was 32.43% and single copy sequence was 67.57% in genome of cryptococcus neoformans respectively. Three specific colonies were isolated from the library. Colony pCNII A6 was serotype A specific, pCNII B5 species specific and pCNIII G1-specific for var. neoformans.


CONCLUSIONS
A rapid diagnosis of Cryptococcus neoformans infection at early stage can be made by using species-specific probe, and serotype and variaty of neoformans and gattii be distinguished in epidemic study.
Wu
J
J
Department of Dermatology, Changzheng Hospital, Second Military Medical University, Shanghai.
Liao
W
W
Chai
J
J
D003001:Cloning, Molecular; D003455:Cryptococcus neoformans / Q000302:isolation & purification*; D015342:DNA Probes; D004271:DNA, Fungal / Q000235:genetics*; D004926:Escherichia coli / Q000235:genetics; D006801:Humans; D016133:Polymerase Chain Reaction; D012703:Serotyping; D013045:Species Specificity
D015342:DNA Probes; D004271:DNA, Fungal