A comparative investigation of azole susceptibility in Candida isolates from vulvovaginal candidiasis and recurrent vulvovaginal candidiasis patients in Ghana.

Vulvovaginal candidiasis (VVC) and recurrent vulvovaginal candidiasis (RVVC) affect millions of women and are typically treated with azoles. We know little about azole susceptibility of Candida species from VVC versus RVVC patients, and nothing about African isolates. We have investigated the susceptibility of Candida isolates from Ghana to fluconazole, itraconazole and/or voriconazole. The percentage of Candida albicans isolates showing susceptibility was significantly lower in RVVC than VVC patients. Isolates of Candida parapsilosis and Candida tropicalis showed a similar trend. For Candida glabrata there was no observed difference. The data indicate a decreased susceptibility in selected Candida species from RVVC patients.

Population Structure of Candida albicans from Three Teaching Hospitals in Ghana.

Previous studies on Candida species in a clinical setting in Ghana have shown a prevalence of Candida albicans. Despite this, very little is known about the various strain types and their population genetic structure. In this study three microsatellite loci, CAI, CAIII and CAVI, were used to investigate the population genetic structure of C. albicans from clinical isolates in Ghana. In all, 240 clinically unrelated C. albicans isolates were recovered from patients reporting at three teaching hospitals. All the isolates were heterozygous for at least one of the three loci, except for one isolate, which was homozygous for all three loci. Sixty-seven unique alleles and 240 different genotypes were generated by the three polymorphic microsatellite loci, resulting in a very high discriminatory potential of approximately 0.98. There was no significant difference in allele frequencies from the small number of anatomical sites sampled, regardless of the host conditions although high genotypic diversities were observed among the isolates. There was evidence for clonal reproduction, including over-expression of observed heterozygotes across the populations. The populations deviated significantly from Hardy-Weinberg equilibrium and pair-wise genotypic linkage disequilibria comparisons across the three loci were significant, also suggesting a clonal population. The overall Wright FIS for the three loci was negative, and the overall FST value was not significantly different from zero for the three loci analyzed, indicating a clonal and homogeneous population across the three sampling locations from Ghana.

The isolation of Candida rugosa and Candida mesorugosa from clinical samples in Ghana.

Members of the Candida rugosa species complex have been described as emerging fungal pathogens and are responsible for a growing number of Candida infections. In this communication we report the isolation of Candida rugosa and Candida mesorugosa in Ghana. To the best of our knowledge this is the first description of this species complex from a clinical setting in Africa.The isolates were identified on the basis of their rRNA gene internal transcribed spacer (ITS) sequences. For one isolate, obtained from sputum, the sequence grouped well with that of C. rugosa. Two other isolates from urine had sequences that grouped with Candida mesorugosa. Morphologically, C. rugosa formed white, wrinkled, and flat colonies on Sabouraud Dextrose Agar (SDA), whereas C. mesorugosa formed white, smooth colonies. On chromogenic medium, the isolates formed small, dry greenish-blue colonies with a pale or white border, similar to C. albicans. The C. rugosa isolate produced pseudohyphae in human serum and on CMA-Tween 80 agar. In contrast, the C. mesorugosa isolates did not generate pseudohyphae in human serum, but generated a few pseudohyphae with abundant blastoconidia on CMA-Tween 80 agar. Growth was observed at 37 °C and 42 °C but not at 45 °C.The two C. mesorugosa isolates had Minimum Inhibitory Concentrations (MICs) of 6 and 48 µg ml(-1) for fluconazole and are thus resistant. The C. rugosa isolate had an MIC of 24 µg ml(-1), indicative of resistance. All three isolates were susceptible to itraconazole and voriconazole (with respective MICs of < 0.125 µg ml(-1)).

Reduced transmission of Mycobacterium africanum compared to Mycobacterium tuberculosis in urban West Africa.

OBJECTIVE: Understanding transmission dynamics is useful for tuberculosis (TB) control. A population-based molecular epidemiological study was conducted to determine TB transmission in Ghana. METHODS: Mycobacterium tuberculosis complex (MTBC) isolates obtained from prospectively sampled pulmonary TB patients between July 2012 and December 2015 were characterized using spoligotyping and standard 15-locus mycobacterial interspersed repetitive unit variable number tandem repeat (MIRU-VNTR) typing for transmission studies. RESULTS: Out of 2309 MTBC isolates, 1082 (46.9%) unique cases were identified, with 1227 (53.1%) isolates belonging to one of 276 clusters. The recent TB transmission rate was estimated to be 41.2%. Whereas TB strains of lineage 4 belonging to M. tuberculosis showed a high recent transmission rate (44.9%), reduced recent transmission rates were found for lineages of Mycobacterium africanum (lineage 5, 31.8%; lineage 6, 24.7%). CONCLUSIONS: The study findings indicate high recent TB transmission, suggesting the occurrence of unsuspected outbreaks in Ghana. The observed reduced transmission rate of M. africanum suggests other factor(s) (host/environmental) may be responsible for its continuous presence in West Africa.