Cryptococcus neoformans is the most common cause of meningitis amongst adult Africans with HIV/AIDS. The widespread use of fluconazole may lead to the emergence of isolates with reduced susceptibility. We studied C. neoformans isolates from HIV-infected patients with cryptococcal meningitis. Genotyping and antifungal testing were performed to assess the genetic diversity, occurrence of mixed infections and in vitro activity of antifungal agents. Isolates were recovered from cerebrospinal fluid prior to systemic antifungal treatment. Six isolates were studied for each sample (a total of 114 isolates from 19 patients). Serotyping was performed via LAC 1 and CAP 64 gene amplification and genotyping was performed using phage M13 core, (GACA)4 and (GTG)5 primers and restriction polymorphism analysis of the URA5 gene. Susceptibilities for amphotericin B, flucytosine, fluconazole, voriconazole and posaconazole were tested by the Sensititre YeastOne® method. All strains were identified as C. neoformans var. grubii serotype A. We identified nine major genotypes. Up to two genotypes were identified in the same sample. None of the isolates were resistant to the studied drugs. However, 13 of 114 strains exhibited a reduced susceptibility to fluconazole and 13 of 114 strains exhibited a reduced susceptibility to flucytosine. No correlation was found between the genotype and susceptibility. This study confirms the prevalence of C. neoformans serotype A in Cameroon. Two genotypes may be responsible for a single episode of cryptococcosis. The possibility of mixed infection and diminished susceptibility to fluconazole or flucytosine must be considered for the management of cryptococcosis.
Minor species of the Candida albicans complex may cause overestimation of the epidemiology of C. albicans, and misidentifications could mask their implication in human pathology. Authors determined the occurrence of minor species of the C. albicans complex (C. africana, C. dubliniensis and C. stellatoidea) among Yaoundé HIV-infected patients, Cameroon. Stool, vaginal discharge, urine and oropharyngeal samples were analysed by mycological diagnosis. Isolates were identified by conventional methods and mass spectrometry (MS; carried out by the matrix-assisted laser desorption-ionisation time-of-flight MS protocol). Candida albicans isolates were thereafter submitted to the PCR amplification of the Hwp1 gene. The susceptibility of isolates to antifungal drugs was tested using the Clinical and Laboratory Standards Institute M27-A3 protocol. From 115 C. albicans obtained isolates, neither C. dubliniensis nor C. stellatoidea was observed; two strains of C. africana (422PV and 448PV) were identified by PCR electrophoretic profiles at 700 bp. These two C. africana strains were vaginal isolates. The isolate 448PV was resistant to ketoconazole at the minimal inhibitory concentration of 2 μg ml(-1), and showed reduced susceptibility to amphotericin B at 1 μg ml(-1). This first report on C. africana occurrence in Cameroon brings clues for the understanding of the global epidemiology of this yeast as well as that of minor species of the C. albicans complex.
Cryptococcal meningitis is a severe opportunistic infection in HIV-infected patients. In Ivory Coast, despite the availability of antiretroviral treatment (ART), this infection is still prevalent. The study investigates the genetic diversity of 363 clinical isolates of Cryptococcus from 61 Ivorian HIV-positive patients, the occurrence of mixed infections and the in vitro antifungal susceptibility of the isolates. Serotyping was performed via LAC1 and CAP64 gene amplification. Genotyping was performed using the phage M13 core (GACA) and (GTG) primers and restriction fragment length polymorphism analysis of the URA5 gene. By PCR fingerprinting, the presence of the three serotypes were demonstrated among the 363 isolates in the population studied: A (n=318; 87.6%), AD (n=40; 11%) and B (n=4; 1.1%). Using PCR fingerprinting with primers M13 (GACA) and (GTG) , we grouped the isolates into 56 molecular subtypes. We observed a high frequency (39.3%) of mixed infections, with up to two different genotypes per sample. None of the isolates were resistant to amphotericin B. Only 0.3% and 1.1% of the isolates were resistant to fluconazole and flucytosine respectively. This study revealed the high genetic diversity among Cryptococcus isolates, the occurrence of mixed infections and a high antifungal susceptibility for the majority of Ivorian cryptococcal isolates.
Genetic diversity analyses were performed by sero-genotyping and multi-locus sequence typing on 252 cryptococcal isolates from 13 HIV-positive Ivorian patients followed-up for cryptococcal meningitis. Antifungal susceptibility analyses were performed according to the CLSI M27A3 method. The majority (67.8%) of the isolates belonged to the Cryptococcus neoformans (serotype A) species complex, with 93% being VNI and 7% being VNII. Cryptococcus deuterogattii VGII (serotype B) represented 16.7% of the strains, while C. neoformans/C. deneoformans VNIII (serotype AD) hybrids accounted for 15.1% of the strains. One strain (0.4%) was not identifiable. Nine different sequence types (STs 5, 6, 23, 40, 93, 207, 311, and a new ST; 555) were identified in the C. neoformans population, while the C. deuterogattii population comprised the single ST 173. The distribution of the strains showed that, while the majority of patients (9/13) harboured a single sequence type, 4 patients showed mixed infections. These patients experienced up to 4 shifts in strain content either at the species and/or ST level during their follow-up. This evolution of diversity over time led to the co-existence of up to 3 different Cryptococcus species and 4 different ST within the same individual during the course of infection. Susceptibility testing showed that all strains were susceptible to amphotericin B while 3.6% of them had a none-wild type phenotype to 5-flucytosine. Concerning fluconazole, 2.9% of C.neoformans serotype A strains and 2.4% of C. deuterogattii had also respectively a none-wild type phenotype to this molecule. All C. neoformans x C. deneoformans serotype AD hybrids had however a wild type phenotype to fluconazole. The present study showed that mixed infections exist and could be of particular importance for care outcomes. Indeed, (i) the different Cryptococcus species are known to exhibit different virulence and different susceptibility patterns to antifungal drugs and (ii) the strains genetic diversity within the samples may influence the susceptibility to antifungal treatment.
At a time when the rates of HIV, hepatitis C virus (HCV), and hepatitis B virus (HBV) infections have risen among injection drug users (IDUs) in other countries in the region, little is known about the prevalence of these infections among Bulgarian injectors and about their sexual risk behaviours. IDUs (n = 773) in a community-based needle exchange programme (NEP) and two major drug treatment facilities in Sofia completed a structured interview and were tested for HIV, HBV, and HCV antibodies. While HCV prevalence in the sample was 73.9%, HBV and HIV prevalence was low -6% and 0.5%, respectively. Having more than 10 sexual partners, having sex with someone with hepatitis C or another IDU, and never using a condom with another IDU were common among those who were recruited through NEP. As 40% of the IDUs reported using NEP, it appears that needle exchange provides an opportunity to reach high-risk populations and prevent sexual transmission of blood-borne pathogens.
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