High diversity of yeast species and strains responsible for vulvovaginal candidiasis in South-East Gabon.

OBJECTIVES: Candida albicans generally remains the principal pathogenic yeast responsible for vulvovaginal candidiasis (VVC), although with variable prevalence. In this study, we evaluated the evolution of the prevalence of the non-Candida albicans Candida (NCAC) species and investigated the genotypic diversity and the population genetic structure of the circulating C. albicans strains associated with VVC in the vicinity of Franceville (Gabon). METHODS: A total of 110 independent isolates were identified using both MALDI-TOF MS and conventional techniques. The population genetic structure of the C. albicans strains was determined by multiple locus variable-number tandem repeat analysis using 4 microsatellite markers. RESULTS: The mean and median age of the patients was 31 years. Seven patients had a mixed infection. C. albicans accounted for 62 % (n=68) of the total isolates. NCAC were dominated by C. glabrata, followed by P. kudriavzevii, C. parapsilosis, C. tropicalis, M. guilliermondii, and C. nivariensis. The cluster analysis revealed a high diversity, with a total of 50 different genotypes. The most represented genotype was shared by only four strains, while the vast majority (39 strains) had a unique MLVA pattern. Geographic clusters were not detected. CONCLUSION: The study provides information on species distribution and possible changing epidemiology while reporting for the first time C. nivariensis in VVC in Africa. This study is also the first to investigate the genotypic diversity of the circulating C. albicans strains associated with VVC in Central Africa. Such analyses would help understand the molecular epidemiology of C. albicans.

Vulvovaginal candidiasis among symptomatic women of childbearing age attended at a Medical Analysis Laboratory in Franceville, Gabon.

BACKGROUND: Vulvovaginal candidiasis (VVC) is one of the most common lower genital tract infections in women; this unpleasant and extremely embarrassing pathology is one of the main reasons for gynaecological consultation. In Gabon, the prevalence of VVC remains poorly described even though VVC is known to be the leading gynaecological condition in several countries. This retrospective cross-sectional study sought to assess the prevalence of VVC among symptomatic women in southeastern Gabon. METHODS: Clinical samples were collected from patients suspected to have VVC during a 2-year period (from January 2016 to December 2017). Gram staining of vaginal smears provided indications of vaginal flora and confirmed the presence of yeast. Sabouraud-chloramphenicol and chromID Candida media were used to isolate yeast, and species identification was performed using morphological tests and the Vitek 2 Compact automated system. RESULTS: For the 873 patients included in this study, the prevalence of VVC was 28.52%. Eleven Candida species were identified, with greater representation of Candidaalbicans (82.73%) than of Non C. albicanscandida (NCAC) (17.27%), which were distributed as follows: Candidafamata (4.02%), Candida spp. (3.61%), Candidarugosa (3.21%), Candidalipolytica (1.61%), Candidaparapsilosis (1.61%), Candidaglabrata (1.21%), Candidatropicalis (0.80%), Candidakrusei (0.40%), Candidadubliniensis (0.40%), and Candidasphaerica (0.40%). CONCLUSION: This study offers the first estimation of VVC among Gabonese women in childbearing age with the symptoms. It showed that VVC is very common in Gabon. C. albicans as the most commonly represented species.

Two distinct STLV-1 subtypes infecting Mandrillus sphinx follow the geographic distribution of their hosts.

The mandrill (Mandrillus sphinx) has been shown to be infected with an STLV-1 closely related to HTLV-1. Two distinct STLV-1 subtypes (D and F) infect wild mandrills with high overall prevalence (27.0%) but are different with respect to their phylogenetic relationship and parallel to the mandrills' geographic range. The clustering of these new STLV-1mnd sequences with HTLV-1 subtype D and F suggests first, past simian-to-human transmissions in Central Africa and second, that species barriers are easier to cross over than geographic barriers.

Simian immunodeficiency virus from mandrill (Mandrillus sphinx) SIVmnd experimentally infects human and nonhuman primate cells.

This study set out to characterize the features of experimental infection by simian immunodeficiency virus in mandrill (SIVmnd) (Mandrillus sphinx), cynomolgus macaque (Macaca fascicularis), rhesus macaque (Macaca mulatta), chimpanzee (Pan troglodytes), African green monkey (Cercopithecus pygerythrus), baboon (Papio cynocephalus) and human cells. Purified cells were exposed to a primary isolate of SIVmnd grown in the infected mandrill peripheral blood mononuclear cells, and viral p27 gag antigen was quantitated by antigen capture ELISA. Human cells have been found to be infected by SIVmnd. SIVmnd infection in cynomolgus macaque, rhesus macaque, baboon, mandrill and human cells were more effective than in vervet and chimpanzee cells. In addition, the lymphocytic cell lines SupT1, CEMx174 and Molt4 clone 8 were consistently infected by SIVmnd, whereas U937, a monocytic cell line, was not.

Wild Mandrillus sphinx are carriers of two types of lentivirus.

Mandrillus sphinx, a large primate living in Cameroon and Gabon and belonging to the Papionini tribe, was reported to be infected by a simian immunodeficiency virus (SIV) (SIVmndGB1) as early as 1988. Here, we have identified a second, highly divergent SIVmnd (designated SIVmnd-2). Genomic organization differs between the two viral types; SIVmnd-2 has the additional vpx gene, like other SIVs naturally infecting the Papionini tribe (SIVsm and SIVrcm) and in contrast to the other SIVmnd type (here designated SIVmnd-1), which is more closely related to SIVs infecting l'hoest (Cercopithecus lhoesti lhoesti) and sun-tailed (Cercopithecus lhoesti solatus) monkeys. Importantly, our epidemiological studies indicate a high prevalence of both types of SIVmnd; all 10 sexually mature wild-living monkeys and 3 out of 17 wild-born juveniles tested were infected. The geographic distribution of SIVmnd seems to be distinct for the two types: SIVmnd-1 viruses were exclusively identified in mandrills from central and southern Gabon, whereas SIVmnd-2 viruses were identified in monkeys from northern and western Gabon, as well as in Cameroon. SIVmnd-2 full-length sequence analysis, together with analysis of partial sequences from SIVmnd-1 and SIVmnd-2 from wild-born or wild-living mandrills, shows that the gag and pol regions of SIVmnd-2 are closest to those of SIVrcm, isolated from red-capped mangabeys (Cercocebus torquatus), while the env gene is closest to that of SIVmnd-1. pol and env sequence analyses of SIV from a related Papionini species, the drill (Mandrillus leucophaeus), shows a closer relationship of SIVdrl to SIVmnd-2 than to SIVmnd-1. Epidemiological surveys of human immunodeficiency virus revealed a case in Cameroon of a human infected by a virus serologically related to SIVmnd, raising the possibility that mandrills represent a viral reservoir for humans similar to sooty mangabeys in Western Africa and chimpanzees in Central Africa.

Comparative analysis of natural killer cell activity, lymphoproliferation and lymphocyte surface antigen expression in nonhuman primates housed at the CIRMF Primate Center, Gabon.

Six different species of nonhuman primates housed at the CIRMF Primate Center, cynomolgus monkeys (Macaca fascicularis), rhesus monkeys (Macaca mulatta), mandrills (Mandrillus sphinx), vervets (Cercopithecus aethiops pygerythrus), chimpanzees (Pan troglodyte) and baboons (Papio hamadryas), were evaluated for their natural killer cell activity and for the ability of their peripheral blood mononuclear cells to proliferate in response to known mitogens (concanavalin A, phytohemagglutinin and staphylococcal enterotoxin A) and to react with a panel of mouse monoclonal antibodies directed against human leukocyte surface antigens. Basic information on normal immune functions in these primates is important because of their use as experimental animal models for the study of human diseases such as acquired immunodeficiency syndrome (AIDS), hepatitis, loiasis and malaria.

Natural infection of a household pet red-capped mangabey (Cercocebus torquatus torquatus) with a new simian immunodeficiency virus.

A seroprevalence survey was conducted for simian immunodeficiency virus (SIV) antibody in household pet monkeys in Gabon. Twenty-nine monkeys representing seven species were analyzed. By using human immunodeficiency virus type 2 (HIV-2)/SIVsm, SIVmnd, and SIVagm antigens, one red-capped mangabey (RCM) (Cercocebus torquatus torquatus) was identified as harboring SIV-cross-reactive antibodies. A virus isolate, termed SIVrcm, was subsequently established from this seropositive RCM by cocultivation of its peripheral blood mononuclear cells (PBMC) with PBMC from seronegative humans or RCMs. SIVrcm was also isolated by cocultivation of CD8-depleted RCM PBMC with Molt 4 clone 8 cells but not with CEMx174 cells. The lack of growth in CEMx174 cells distinguished this new SIV from all previously reported sooty mangabey-derived viruses (SIVsm), which grow well in this cell line. SIVrcm was also successfully transmitted (cell free) to human and rhesus PBMC as well as to Molt 4 clone 8 cells. To determine the evolutionary origins of this newly identified virus, subgenomic pol (475 bp) and gag (954 bp) gene fragments were amplified from infected cell culture DNA and sequenced. The position of SIVrcm relative to those of members of the other primate lentivirus lineages was then examined in evolutionary trees constructed from deduced protein sequences. This analysis revealed significantly discordant phylogenetic positions of SIVrcm in the two genomic regions. In trees derived from partial gag sequences, SIVrcm clustered independently from all other HIV and SIV strains, consistent with a new primate lentivirus lineage. However, in trees derived from pol sequences, SIVrcm grouped with the HIV-1/SIVcpz lineage. These findings suggest that the SIVrcm genome is mosaic and possibly is the result of a recombination event involving divergent lentiviruses in the distant past. Further analysis of this and other SIVrcm isolates may shed new light on the origin of HIV-1.