Characterization of HIV-1 gag and nef in Cameroon: further evidence of extreme diversity at the origin of the HIV-1 group M epidemic

BACKGROUND: Cameroon, in west central Africa, has an extraordinary degree of HIV diversity, presenting a major challenge for the development of an effective HIV vaccine. Given the continuing need to closely monitor the emergence of new HIV variants in the country, we analyzed HIV-1 genetic diversity in 59 plasma samples from HIV-infected Cameroonian blood donors. Full length HIV gag and nef sequences were generated and phylogenetic analyses were performed. FINDINGS: All gag and nef sequences clustered within HIV-1M. Circulating recombinant form CRF02_AG predominated, accounting for 50% of the studied infections, followed by clade G (11%), clade D and CRF37_cpx (4% each), and clades A, F, CRF01_AE and CRF36_cpx (2% each). In addition, 22% of the studied viruses apparently had nef and gag genes from viruses belonging to different clades, with the majority (8/10) having either a nef or gag gene derived from CRF02_AG. Interestingly, five gag sequences (10%) and three (5%) nef sequences were neither obviously recombinant nor easily classifiable into any of the known HIV-1M clades. CONCLUSION: This suggests the widespread existence of highly divergent HIV lineages in Cameroon. While the genetic complexity of the Cameroonian HIV-1 epidemic has potentially serious implications for the design of biomedical interventions, detailed analyses of divergent Cameroonian HIV-1M lineages could be crucial for dissecting the earliest evolutionary steps in the emergence of HIV-1M

Noninvasive western lowland gorilla's health monitoring: A decade of simian immunodeficiency virus surveillance in southern Cameroon.

Simian immunodeficiency virus (SIVgor) causes persistent infection in critically endangered western lowland gorillas (Gorilla gorilla gorilla) from west central Africa. SIVgor is closely related to chimpanzee and human immunodeficiency viruses (SIVcpz and HIV-1, respectively). We established a noninvasive method that does not interfere with gorillas' natural behaviour to provide wildlife pathogen surveillance and health monitoring for conservation. A total of 1,665 geo-referenced fecal samples were collected at regular intervals from February 2006 to December 2014 (123 sampling days) in the Campo-Ma'an National Park (southwest Cameroon). Host genotyping was performed using microsatellite markers, SIVgor infection was identified by serology and genetic amplification was attempted on seropositive individuals. We identified at least 125 distinct gorillas, 50 were resampled (observed 3.5 times in average) and 38 were SIVgor+ (seven individuals were seroconverters). Six groups of gorillas were identified based on the overlapping occurrence of individuals with apparent high rates of gene flow. We obtained SIVgor genetic sequences from 25 of 38 seropositive genotyped gorillas and showed that the virus follows exponential growth dynamics under a strict molecular clock. Different groups shared SIVgor lineages demonstrating intergroup viral spread and recapture of positive individuals illustrated intra-host viral evolution. Relatedness and relationship genetic analysis of gorillas together with Bayesian phylogenetic inference of SIVgor provided evidence suggestive of vertical transmission. In conclusion, we provided insights into gorilla social dynamics and SIVgor evolution and emphasized the utility of noninvasive sampling to study wildlife health populations. These findings contribute to prospective planning for better monitoring and conservation

Екологія: наукова сутність, об'єкти досліджень, завдання

Розкрита суть чотирьох основних розділів екології: аутекології, демекології, синекології та екосистемології; описані об’єкти, предмет і завдання останньої. Визначена роль розумової і виробничої діяльности людства як зовнішнього збурювального чинника щодо живих систем і як організатора соціосфери. Обґрунтовані завдання екосистемології у теперішніх геосоціальних умовах.The matters of the four main divisions in ecology, such as autecology, demecology, synecology and ecosystemology have been uncovered. The objects, subjects and assignments of the latter were described too. A part of mankind’s mental and industrial activities, which are outside disturbing factors for biosystems and sociosphere organisers, has been determined. The assignments of ecosystemology within present geosocial condition were well grounded in the article

Genetic characterization of the complete genome of a highly divergent simian T-lymphotropic virus (STLV) type 3 from a wild Cercopithecus mona monkey

<p>Abstract</p> <p>Background</p> <p>The recent discoveries of novel human T-lymphotropic virus type 3 (HTLV-3) and highly divergent simian T-lymphotropic virus type 3 (STLV-3) subtype D viruses from two different monkey species in southern Cameroon suggest that the diversity and cross-species transmission of these retroviruses are much greater than currently appreciated.</p> <p>Results</p> <p>We describe here the first full-length sequence of a highly divergent STLV-3d(Cmo8699AB) virus obtained by PCR-based genome walking using DNA from two dried blood spots (DBS) collected from a wild-caught <it>Cercopithecus mona </it>monkey. The genome of STLV-3d(Cmo8699AB) is 8913-bp long and shares only 77% identity to other PTLV-3s. Phylogenetic analyses using Bayesian and maximum likelihood inference clearly show that this highly divergent virus forms an independent lineage with high posterior probability and bootstrap support within the diversity of PTLV-3. Molecular dating of concatenated <it>gag-pol-env-tax </it>sequences inferred a divergence date of about 115,117 years ago for STLV-3d(Cmo8699AB) indicating an ancient origin for this newly identified lineage. Major structural, enzymatic, and regulatory gene regions of STLV-3d(Cmo8699AB) are intact and suggest viral replication and a predicted pathogenic potential comparable to other PTLV-3s.</p> <p>Conclusion</p> <p>When taken together, the inferred ancient origin of STLV-3d(Cmo8699AB), the presence of this highly divergent virus in two primate species from the same geographical region, and the ease with which STLVs can be transmitted across species boundaries all suggest that STLV-3d may be more prevalent and widespread. Given the high human exposure to nonhuman primates in this region and the unknown pathogenicity of this divergent PTLV-3, increased surveillance and expanded prevention activities are necessary. Our ability to obtain the complete viral genome from DBS also highlights further the utility of this method for molecular-based epidemiologic studies.</p

Risk to Human Health from a Plethora of Simian Immunodeficiency Viruses in Primate Bushmeat

To assess human exposure to Simian immunodeficiency virus (SIV) in west central Africa, we looked for SIV infection in 788 monkeys that were hunted in the rainforests of Cameroon for bushmeat or kept as pets. Serologic reactivity suggesting SIV infection was found in 13 of 16 primate species, including 4 not previously known to harbor SIV. Overall, 131 sera (16.6%) reacted strongly and an additional 34 (4.3%) reacted weakly with HIV antigens. Molecular analysis identified five new phylogenetic SIV lineages. These data document for the first time that a substantial proportion of wild monkeys in Cameroon are SIV infected and that humans who hunt and handle bushmeat are exposed to a plethora of genetically highly divergent viruses

Origin and Biology of Simian Immunodeficiency Virus in Wild-Living Western Gorillas

Western lowland gorillas (Gorilla gorilla gorilla) are infected with a simian immunodeficiency virus (SIVgor) that is closely related to chimpanzee and human immunodeficiency viruses (SIVcpz and HIV-1, respectively) in west central Africa. Although existing data suggest a chimpanzee origin for SIVgor, a paucity of available sequences has precluded definitive conclusions. Here, we report the molecular characterization of one partial (BQ664) and three full-length (CP684, CP2135, and CP2139) SIVgor genomes amplified from fecal RNAs of wild-living gorillas at two field sites in Cameroon. Phylogenetic analyses showed that all SIVgor strains clustered together, forming a monophyletic lineage throughout their genomes. Interestingly, the closest relatives of SIVgor were not SIVcpzPtt strains from west central African chimpanzees (Pan troglodytes troglodytes) but human viruses belonging to HIV-1 group O. In trees derived from most genomic regions, SIVgor and HIV-1 group O formed a sister clade to the SIVcpzPtt lineage. However, in a tree derived from 5' pol sequences (similar to 900 bp), SIVgor and HIV-1 group O fell within the SIVcpzPtt radiation. The latter was due to two SIVcpzPtt strains that contained mosaic pol sequences, pointing to the existence of a divergent SIVcpzPtt lineage that gave rise to SIVgor and HIV-1 group O. Gorillas appear to have acquired this lineage at least 100 to 200 years ago. To examine the biological properties of SIVgor, we synthesized a full-length provirus from fecal consensus sequences. Transfection of the resulting clone (CP2139.287) into 293T cells yielded infectious virus that replicated efficiently in both human and chimpanzee CD4(+) T cells and used CCR5 as the coreceptor for viral entry. Together, these results provide strong evidence that P. t. troglodytes apes were the source of SIVgor. These same apes may also have spawned the group O epidemic; however, the possibility that gorillas served as an intermediary host cannot be excluded

Ubiquitous Hepatocystis infections, but no evidence of Plasmodium falciparum-like malaria parasites in wild greater spot-nosed monkeys (Cercopithecus nictitans)

Western gorillas (Gorilla gorilla) have been identified as the natural reservoir of the parasites that were the immediate precursor of Plasmodium falciparum infecting humans. Recently, a P. falciparum-like sequence was reported in a sample from a captive greater spot-nosed monkey (Cercopithecus nictitans), and was taken to indicate that this species may also be a natural reservoir for P. falciparum-related parasites. To test this hypothesis we screened blood samples from 292 wild C nictitans monkeys that had been hunted for bushmeat in Cameroon. We detected Hepatocystis spp. in 49% of the samples, as well as one sequence from a clade of Plasmodium spp. previously found in birds, lizards and bats. However, none of the 292 wild C. nictitans harbored P. falciparum-like parasites

Central African Hunters Exposed to Simian Immunodeficiency Virus

HIV-seronegative Cameroonians with exposure to nonhuman primates were tested for simian immunodeficiency virus (SIV) infection. Seroreactivity was correlated with exposure risk (p<0.001). One person had strong humoral and weak cellular immune reactivity to SIVcol peptides. Humans are exposed to and possibly infected with SIV, which has major public health implications

Chimpanzee reservoirs of pandemic and nonpandemic HIV-1

Human immunodeficiency virus type 1 (HIV-1), the cause of human acquired immunodeficiency syndrome ( AIDS), is a zoonotic infection of staggering proportions and social impact. Yet uncertainty persists regarding its natural reservoir. The virus most closely related to HIV-1 is a simian immunodeficiency virus ( SIV) thus far identified only in captive members of the chimpanzee subspecies Pan troglodytes troglodytes. Here we report the detection of SIVcpz antibodies and nucleic acids in fecal samples from wild-living P.t. troglodytes apes in southern Cameroon, where prevalence rates in some communities reached 29 to 35%. By sequence analysis of endemic SIVcpz strains, we could trace the origins of pandemic ( group M) and nonpandemic ( group N) HIV-1 to distinct, geographically isolated chimpanzee communities. These findings establish P. t. troglodytes as a natural reservoir of HIV-1