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Origin of Cryptococcus neoformans var. neoformans diploid strains.
J Clin Microbiol. 2001 Nov; 39(11):3889-94.JC

Abstract

The basidiomycetous yeast Cryptococcus neoformans is an important human fungal pathogen. Two varieties, C. neoformans var. neoformans and C. neoformans var. gattii, have been identified. Both are heterothallic with two mating types, MATa and MATalpha. Some rare isolates are self-fertile and are considered occasional diploid or aneuploid strains. In the present study, 133 isolates, mostly from Italian patients, were investigated to detect the presence of diploid strains in the Igiene Università Milano culture collection. All of the diploid isolates were further investigated by different methods to elucidate their origins. Forty-nine diploid strains were identified by flow cytometry. PCR fingerprinting using the (GACA)(4) primer showed that the diploid state was associated with two specific genotypes identified as VN3 and VN4. Determination of mating type on V8 juice medium confirmed that the majority of the strains were sterile. PCR and dot blotting using the two pheromone genes (MFa and MFalpha) as probes identified 36 of the 49 diploid isolates as MATa/alpha. The results of pheromone gene sequencing showed that two allelic MFalpha genes exist and are distinct for serotypes A and D. In contrast, the MFa gene sequence was conserved in both serotype alleles. Amplification of serotype-specific STE20 alleles demonstrated that the diploid strains contained one mating locus inherited from a serotype A parent and one inherited from a serotype D parent. The present results suggest that diploid isolates may be common among the C. neoformans population and that in Italy and other European countries serotype A and D populations are not genetically isolated but are able to recombine by sexual reproduction.

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Authors+Show Affiliations

Cogliati M
Laboratorio di Micologia Medica, Istituto di Igiene e Medicina Preventiva, Università degli Studi, IRCCS Ospedale Maggiore, 20122 Milan, Italy.
Esposto MC
No affiliation info available
Clarke DL
No affiliation info available
Wickes BL
No affiliation info available
Viviani MA
No affiliation info available

MeSH

CryptococcosisCryptococcus neoformansCulture MediaDNA FingerprintingDiploidyFlow CytometryHaploidyHumansMolecular Sequence DataPheromonesPolymerase Chain ReactionSequence Analysis, DNASerotypingVegetables

Pub Type(s)

Journal Article
Research Support, Non-U.S. Gov't
Research Support, U.S. Gov't, P.H.S.

Language

eng

PubMed ID

11682503

Citation

Cogliati, M, et al. "Origin of Cryptococcus Neoformans Var. Neoformans Diploid Strains." Journal of Clinical Microbiology, vol. 39, no. 11, 2001, pp. 3889-94.
Cogliati M, Esposto MC, Clarke DL, et al. Origin of Cryptococcus neoformans var. neoformans diploid strains. J Clin Microbiol. 2001;39(11):3889-94.
Cogliati, M., Esposto, M. C., Clarke, D. L., Wickes, B. L., & Viviani, M. A. (2001). Origin of Cryptococcus neoformans var. neoformans diploid strains. Journal of Clinical Microbiology, 39(11), 3889-94.
Cogliati M, et al. Origin of Cryptococcus Neoformans Var. Neoformans Diploid Strains. J Clin Microbiol. 2001;39(11):3889-94. PubMed PMID: 11682503.
* Article titles in AMA citation format should be in sentence-case
TY - JOUR T1 - Origin of Cryptococcus neoformans var. neoformans diploid strains. AU - Cogliati,M, AU - Esposto,M C, AU - Clarke,D L, AU - Wickes,B L, AU - Viviani,M A, PY - 2001/10/30/pubmed PY - 2002/3/14/medline PY - 2001/10/30/entrez SP - 3889 EP - 94 JF - Journal of clinical microbiology JO - J Clin Microbiol VL - 39 IS - 11 N2 - The basidiomycetous yeast Cryptococcus neoformans is an important human fungal pathogen. Two varieties, C. neoformans var. neoformans and C. neoformans var. gattii, have been identified. Both are heterothallic with two mating types, MATa and MATalpha. Some rare isolates are self-fertile and are considered occasional diploid or aneuploid strains. In the present study, 133 isolates, mostly from Italian patients, were investigated to detect the presence of diploid strains in the Igiene Università Milano culture collection. All of the diploid isolates were further investigated by different methods to elucidate their origins. Forty-nine diploid strains were identified by flow cytometry. PCR fingerprinting using the (GACA)(4) primer showed that the diploid state was associated with two specific genotypes identified as VN3 and VN4. Determination of mating type on V8 juice medium confirmed that the majority of the strains were sterile. PCR and dot blotting using the two pheromone genes (MFa and MFalpha) as probes identified 36 of the 49 diploid isolates as MATa/alpha. The results of pheromone gene sequencing showed that two allelic MFalpha genes exist and are distinct for serotypes A and D. In contrast, the MFa gene sequence was conserved in both serotype alleles. Amplification of serotype-specific STE20 alleles demonstrated that the diploid strains contained one mating locus inherited from a serotype A parent and one inherited from a serotype D parent. The present results suggest that diploid isolates may be common among the C. neoformans population and that in Italy and other European countries serotype A and D populations are not genetically isolated but are able to recombine by sexual reproduction. SN - 0095-1137 UR - https://www.unboundmedicine.com/medline/citation/11682503/Origin_of_Cryptococcus_neoformans_var__neoformans_diploid_strains_ L2 - https://journals.asm.org/doi/10.1128/JCM.39.11.3889-3894.2001?url_ver=Z39.88-2003&rfr_id=ori:rid:crossref.org&rfr_dat=cr_pub=pubmed DB - PRIME DP - Unbound Medicine ER -