title: Comparison of biotyping methods as alternative identification tools to molecular typing of pathogenic Cryptococcus species in sub-Saharan Africa.
abstract: Cryptococcal meningitis is the leading fungal infection and AIDS defining opportunistic illness in patients with late stage HIV infection, particularly in South-East Asia and sub-Saharan Africa. Given the high mortality, clinical differences and the extensive ecological niche of Cryptococcus neoformans and Cryptococcus gattii species complexes, there is need for laboratories in sub-Sahara African countries to adopt new and alternative reliable diagnostic algorithms that rapidly identify and distinguish these species. We biotyped 74 and then amplified fragment length polymorphism (AFLP) genotyped 66 Cryptococcus isolates from a cohort of patients with HIV-associated cryptococcal meningitis. C. gattii sensu lato was isolated at a prevalence of 16.7% (n = 11/66) and C. neoformans sensu stricto was responsible for 83.3% (n = 55/66) of the infections. l-Canavanine glycine bromothymol blue, yeast-carbon-base-d-proline-d-tryptophan and creatinine dextrose bromothymol blue thymine were able to distinguish pathogenic C. gattii sensu lato from C. neoformans sensu stricto species when compared with AFLP genotyping. This study demonstrates high C. gattii sensu lato prevalence in Zimbabwe. In addition, biotyping methods can be used as alternative diagnostic tools to molecular typing in resource-limited areas for differentiating pathogenic Cryptococcus species.
authors.affiliation: Department of Chemical Pathology, College of Health Sciences, University of Zimbabwe, Harare, Zimbabwe.|Department of Medical Microbiology, College of Health Sciences, University of Zimbabwe, Harare, Zimbabwe.
authors.forename: Tinashe K
authors.initials: TK
authors.lastname: Nyazika
authors.affiliation: Department of Medical Microbiology, College of Health Sciences, University of Zimbabwe, Harare, Zimbabwe.
authors.forename: Valerie J
authors.initials: VJ
authors.lastname: Robertson
authors.affiliation: Department of Chemical Pathology, College of Health Sciences, University of Zimbabwe, Harare, Zimbabwe.
authors.forename: Brenda
authors.initials: B
authors.lastname: Nherera
authors.affiliation: Department of Chemical Pathology, College of Health Sciences, University of Zimbabwe, Harare, Zimbabwe.
authors.forename: Prichard T
authors.initials: PT
authors.lastname: Mapondera
authors.affiliation: Department of Medical Microbiology and Infectious Diseases, Canisius-Wilhelmina Hospital, Nijmegen, The Netherlands.|Department of Medical Microbiology, Radboudumc, Nijmegen, The Netherlands.
authors.forename: Jacques F
authors.initials: JF
authors.lastname: Meis
authors.affiliation: Department of Medical Microbiology and Infectious Diseases, Canisius-Wilhelmina Hospital, Nijmegen, The Netherlands.
authors.forename: Ferry
authors.identifier: http://orcid.org/0000-0002-5622-1916
authors.initials: F
authors.lastname: Hagen
mesh_terms: D000328:Adult; D017954:Africa South of the Sahara / Q000453:epidemiology; D054458:Amplified Fragment Length Polymorphism Analysis; D002555:Cerebrospinal Fluid / Q000382:microbiology; D015331:Cohort Studies; D003454:Cryptococcus / Q000145:classification* / Q000235:genetics / Q000302:isolation & purification / Q000472:pathogenicity; D003470:Culture Media / Q000737:chemistry; D060005:Genotyping Techniques; D015658:HIV Infections / Q000150:complications; D006801:Humans; D016919:Meningitis, Cryptococcal / Q000175:diagnosis* / Q000453:epidemiology / Q000382:microbiology; D016533:Mycological Typing Techniques / Q000379:methods* / Q000592:standards; D015995:Prevalence; D012680:Sensitivity and Specificity
chemical_list: D003470:Culture Media
keywords: Biotyping; Cryptococcus gattii sensu lato; Cryptococcus neoformans sensu stricto; amplified fragment length polymorphism