Dual infections with pigmented and albino strains of Cryptococcus neoformans in patients with or without human immunodeficiency virus infection in India

Piyali Mandal, Uma Banerjee, Arturo Casadevall, Joshua D. Nosanchuk

Research output: Contribution to journalArticle

20 Citations (Scopus)

Abstract

Cryptococcus neoformans is an encapsulated yeast-like fungus of worldwide distribution. Melanin production is an important virulence factor of C. neoformans. We report the identification of distinct cryptococcal isolates with either pigmented or white colony phenotypes on L-dihydroxyphenylalanine agar plates in three patients who presented with meningitis to the All India Institute of Medical Sciences in India. Two of the patients were also infected with human immunodeficiency virus. Biochemical studies, India ink analysis, immunofluorescence with antibodies specific to capsular antigen, and serotyping confirmed that the melanotic and albino strains were C. neoformans serotypes A and D, respectively. Genotyping with M13 and [GACA]4 primers revealed that all the C. neoformans isolates were genetically different. The CNLAC1 gene associated with melanin production was identified in all the strains by PCR. Standard MIC testing revealed that the strains had similar susceptibilities to amphotericin B, but time-kill assays with the antifungal showed reduced susceptibility in melanin-producing strains. Infection studies with A/Jcr mice showed that the melanin-lacking yeast were less virulent than melanin-producing isolates. These findings indicate that these patients had dual infections with pigmented and albino strains of C. neoformans that were phenotypically and biologically different. Continued surveillance of primary isolates from patients with cryptococcosis by analyzing phenotypic differences and by molecular methods may reveal that mixed infections occur more commonly than is currently realized.

Original languageEnglish (US)
Pages (from-to)4766-4772
Number of pages7
JournalJournal of Clinical Microbiology
Volume43
Issue number9
DOIs
StatePublished - Sep 2005

Fingerprint

Cryptococcus neoformans
Melanins
Virus Diseases
India
HIV
Infection
Yeasts
Cryptococcosis
Serotyping
Dihydroxyphenylalanine
Amphotericin B
Virulence Factors
Coinfection
Meningitis
Agar
Fluorescent Antibody Technique
Fungi
Phenotype
Antigens
Polymerase Chain Reaction

ASJC Scopus subject areas

  • Microbiology (medical)
  • Microbiology

Cite this

Dual infections with pigmented and albino strains of Cryptococcus neoformans in patients with or without human immunodeficiency virus infection in India. / Mandal, Piyali; Banerjee, Uma; Casadevall, Arturo; Nosanchuk, Joshua D.

In: Journal of Clinical Microbiology, Vol. 43, No. 9, 09.2005, p. 4766-4772.

Research output: Contribution to journalArticle

@article{6f2a8da6aca7454c8d881237169611d7,
title = "Dual infections with pigmented and albino strains of Cryptococcus neoformans in patients with or without human immunodeficiency virus infection in India",
abstract = "Cryptococcus neoformans is an encapsulated yeast-like fungus of worldwide distribution. Melanin production is an important virulence factor of C. neoformans. We report the identification of distinct cryptococcal isolates with either pigmented or white colony phenotypes on L-dihydroxyphenylalanine agar plates in three patients who presented with meningitis to the All India Institute of Medical Sciences in India. Two of the patients were also infected with human immunodeficiency virus. Biochemical studies, India ink analysis, immunofluorescence with antibodies specific to capsular antigen, and serotyping confirmed that the melanotic and albino strains were C. neoformans serotypes A and D, respectively. Genotyping with M13 and [GACA]4 primers revealed that all the C. neoformans isolates were genetically different. The CNLAC1 gene associated with melanin production was identified in all the strains by PCR. Standard MIC testing revealed that the strains had similar susceptibilities to amphotericin B, but time-kill assays with the antifungal showed reduced susceptibility in melanin-producing strains. Infection studies with A/Jcr mice showed that the melanin-lacking yeast were less virulent than melanin-producing isolates. These findings indicate that these patients had dual infections with pigmented and albino strains of C. neoformans that were phenotypically and biologically different. Continued surveillance of primary isolates from patients with cryptococcosis by analyzing phenotypic differences and by molecular methods may reveal that mixed infections occur more commonly than is currently realized.",
author = "Piyali Mandal and Uma Banerjee and Arturo Casadevall and Nosanchuk, {Joshua D.}",
year = "2005",
month = "9",
doi = "10.1128/JCM.43.9.4766-4772.2005",
language = "English (US)",
volume = "43",
pages = "4766--4772",
journal = "Journal of Clinical Microbiology",
issn = "0095-1137",
publisher = "American Society for Microbiology",
number = "9",

}

TY - JOUR

T1 - Dual infections with pigmented and albino strains of Cryptococcus neoformans in patients with or without human immunodeficiency virus infection in India

AU - Mandal, Piyali

AU - Banerjee, Uma

AU - Casadevall, Arturo

AU - Nosanchuk, Joshua D.

PY - 2005/9

Y1 - 2005/9

N2 - Cryptococcus neoformans is an encapsulated yeast-like fungus of worldwide distribution. Melanin production is an important virulence factor of C. neoformans. We report the identification of distinct cryptococcal isolates with either pigmented or white colony phenotypes on L-dihydroxyphenylalanine agar plates in three patients who presented with meningitis to the All India Institute of Medical Sciences in India. Two of the patients were also infected with human immunodeficiency virus. Biochemical studies, India ink analysis, immunofluorescence with antibodies specific to capsular antigen, and serotyping confirmed that the melanotic and albino strains were C. neoformans serotypes A and D, respectively. Genotyping with M13 and [GACA]4 primers revealed that all the C. neoformans isolates were genetically different. The CNLAC1 gene associated with melanin production was identified in all the strains by PCR. Standard MIC testing revealed that the strains had similar susceptibilities to amphotericin B, but time-kill assays with the antifungal showed reduced susceptibility in melanin-producing strains. Infection studies with A/Jcr mice showed that the melanin-lacking yeast were less virulent than melanin-producing isolates. These findings indicate that these patients had dual infections with pigmented and albino strains of C. neoformans that were phenotypically and biologically different. Continued surveillance of primary isolates from patients with cryptococcosis by analyzing phenotypic differences and by molecular methods may reveal that mixed infections occur more commonly than is currently realized.

AB - Cryptococcus neoformans is an encapsulated yeast-like fungus of worldwide distribution. Melanin production is an important virulence factor of C. neoformans. We report the identification of distinct cryptococcal isolates with either pigmented or white colony phenotypes on L-dihydroxyphenylalanine agar plates in three patients who presented with meningitis to the All India Institute of Medical Sciences in India. Two of the patients were also infected with human immunodeficiency virus. Biochemical studies, India ink analysis, immunofluorescence with antibodies specific to capsular antigen, and serotyping confirmed that the melanotic and albino strains were C. neoformans serotypes A and D, respectively. Genotyping with M13 and [GACA]4 primers revealed that all the C. neoformans isolates were genetically different. The CNLAC1 gene associated with melanin production was identified in all the strains by PCR. Standard MIC testing revealed that the strains had similar susceptibilities to amphotericin B, but time-kill assays with the antifungal showed reduced susceptibility in melanin-producing strains. Infection studies with A/Jcr mice showed that the melanin-lacking yeast were less virulent than melanin-producing isolates. These findings indicate that these patients had dual infections with pigmented and albino strains of C. neoformans that were phenotypically and biologically different. Continued surveillance of primary isolates from patients with cryptococcosis by analyzing phenotypic differences and by molecular methods may reveal that mixed infections occur more commonly than is currently realized.

UR - http://www.scopus.com/inward/record.url?scp=24744447437&partnerID=8YFLogxK

UR - http://www.scopus.com/inward/citedby.url?scp=24744447437&partnerID=8YFLogxK

U2 - 10.1128/JCM.43.9.4766-4772.2005

DO - 10.1128/JCM.43.9.4766-4772.2005

M3 - Article

C2 - 16145139

AN - SCOPUS:24744447437

VL - 43

SP - 4766

EP - 4772

JO - Journal of Clinical Microbiology

JF - Journal of Clinical Microbiology

SN - 0095-1137

IS - 9

ER -