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Avelin F. Aghokeng - One of the best experts on this subject based on the ideXlab platform.
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Characterization of a new simian immunodeficiency virus strain in a naturally infected Pan Troglodytes Troglodytes chimpanzee with AIDS related symptoms
Retrovirology, 2011Co-Authors: Lucie Etienne, Eric Nerrienet, Matthew Lebreton, Godwin Tafon Bibila, Yacouba Foupouapouognigni, Dominique Rousset, Ahmadou Nana, Cyrille F. Djoko, Ubald Tamoufe, Avelin F. AghokengAbstract:Background Data on the evolution of natural SIV infection in chimpanzees (SIVcpz) and on the impact of SIV on local ape populations are only available for Eastern African chimpanzee subspecies (Pan Troglodytes schweinfurthii), and no data exist for Central chimpanzees (Pan Troglodytes Troglodytes), the natural reservoir of the ancestors of HIV-1 in humans. Here, we report a case of naturally-acquired SIVcpz infection in a P.t.Troglodytes chimpanzee with clinical and biological data and analysis of viral evolution over the course of infection.
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characterization of a new simian immunodeficiency virus strain in a naturally infected pan Troglodytes Troglodytes chimpanzee with aids related symptoms
Retrovirology, 2011Co-Authors: Lucie Etienne, Eric Nerrienet, Matthew Lebreton, Godwin Tafon Bibila, Yacouba Foupouapouognigni, Dominique Rousset, Ahmadou Nana, Cyrille F. Djoko, Ubald Tamoufe, Avelin F. AghokengAbstract:Background: Data on the evolution of natural SIV infection in chimpanzees (SIVcpz) and on the impact of SIV on local ape populations are only available for Eastern African chimpanzee subspecies (Pan Troglodytes schweinfurthii), and no data exist for Central chimpanzees (Pan Troglodytes Troglodytes), the natural reservoir of the ancestors of HIV-1 in humans. Here, we report a case of naturally-acquired SIVcpz infection in a P.t.Troglodytes chimpanzee with clinical and biological data and analysis of viral evolution over the course of infection. Results: A male chimpanzee (Cam155), 1.5 years, was seized in southern Cameroon in November 2003 and screened SIV positive during quarantine. Clinical follow-up and biological analyses have been performed for 7 years and showed a significant decline of CD4 counts (1,380 cells/mm 3 in 2004 vs 287 in 2009), a severe thrombocytopenia (130,000 cells/mm 3 in 2004 vs 5,000 cells/mm 3 in 2009), a weight loss of 21.8% from August 2009 to January 2010 (16 to 12.5 kg) and frequent periods of infections with diverse pathogens. DNA from PBMC, leftover from clinical follow-up samples collected in 2004 and 2009, was used to amplify overlapping fragments and sequence two full-length SIVcpzPtt-Cam155 genomes. SIVcpzPtt-Cam155 was phylogenetically related to other SIVcpzPtt from Cameroon (SIVcpzPtt-Cam13) and Gabon (SIVcpzPtt-Gab1). Ten molecular clones 5 years apart, spanning the V1V4 gp120 env region (1,100 bp), were obtained. Analyses of the env region showed positive selection (dN-dS >0), intra-host length variation and extensive amino acid diversity between clones, greater in 2009. Over 5 years, N-glycosylation site frequency significantly increased (p < 0.0001). Conclusions: Here, we describe for the first time the clinical history and viral evolution of a naturally SIV infected P.t.Troglodytes chimpanzee. The findings show an increasing viral diversity over time and suggest clinical progression to an AIDS-like disease, showing that SIVcpz can be pathogenic in its host, as previously described in P.t.schweinfurthii. Although studying the impact of SIV infection in wild apes is difficult, efforts should be made to better characterize the pathogenicity of the ancestors of HIV-1 in their natural host and to find out whether SIV infection also plays a role in ape population decline.
Martine Peeters - One of the best experts on this subject based on the ideXlab platform.
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Assessment of gastrointestinal parasites in wild chimpanzees (Pan Troglodytes Troglodytes) in southeast Cameroon
Parasitology Research, 2014Co-Authors: Pascal Drakulovski, Sabrina Locatelli, Sébastien Pion, Christelle Butel, Eric Delaporte, Sebastien Bertout, Martine Peeters, Eitel Mpoudi Ngole, Michèle MalliéAbstract:We tested 114 faecal samples from wild simian immunodeficiency virus (SIV)-positive ( n = 43) and SIV-negative ( n = 71) chimpanzees ( Pan Troglodytes Troglodytes ) in southeast Cameroon for the presence of gastrointestinal parasites by direct smear. We observed cysts from different protozoa ( Entamoeba coli and Entamoeba histolytica / Entamoeba dispar , Endolimax nana , Iodamoeba butschlii , Chilomastix mesnili , Balantidium coli and Blastocystis cells) and trophozoites from Troglodytella abrassarti and Balantidium coli . Eggs from different helminths (strongylids, Ascaris lumbricoides , Abbreviata caucasica , Trichuris sp., Capillaria sp., Enterobius anthropopeci , Bertiella sp . , Hymenolepis diminuta and an undetermined fluke) were also observed. Finally, we observed eggs that could not be properly identified and classified. We did not observe any differences between the SIV + and SIV − samples except for the unidentified eggs. The studied chimpanzees were highly parasitised by strongylid (85.1 % of prevalence), Troglodytella (43.8 %) and Blastocystis (2.9 %), and the frequency of the other parasites ranged from 0.9 to 8.8 %. These high levels of parasite infections could represent an additional burden in a population where there is a high rate of the SIV virus in circulation.
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Use of RNAlater as a preservation method for parasitic coprology studies in wild-living chimpanzees.
Experimental parasitology, 2013Co-Authors: Pascal Drakulovski, Sabrina Locatelli, Sébastien Pion, Christelle Butel, Eric Delaporte, Martine Peeters, D. Krasteva, E. Mougdi-pole, Michèle MalliéAbstract:We evaluated the use of an RNA stabilisation buffer, RNAlater® (Ambion, Austin, Texas), as a preservation medium for parasitic coprology analysis of faecal samples collected from chimpanzees living in the wild (Pan Troglodytes Troglodytes). Thirty faecal samples collected in the forests of south-east Cameroon (Mambele area) from 2003 to 2011 were preserved in RNAlater® at −80 °C and analysed for their parasite content. We identified and counted parasitic elements and assessed their shape, size and morphology in relation to the storage time of the samples. We found that parasite elements were identifiable in RNAlater® preserved samples after as many as 7 years, showing that RNAlater® could be an effective and reliable preservation medium for coprology. Thus, its use could be an interesting way to optimise sample collection for several types of studies (parasitology and bacteriology/virology) at once, especially considering the logistically challenging and time-consuming field campaigns needed to obtain these faecal samples.
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The transmembrane domain of HIV-1 Vpu is sufficient to confer anti-tetherin activity to SIVcpz and SIVgor Vpu proteins: cytoplasmic determinants of Vpu function
Retrovirology, 2013Co-Authors: Silvia F. Kluge, Martine Peeters, Frederic Bibollet-ruche, Daniel Sauter, Michael Vogl, Beatrice H. Hahn, Frank KirchhoffAbstract:Background The acquisition of effective Vpu-mediated anti-tetherin activity to promote virion release following transmission of SIVcpzPtt from central chimpanzees (Pan Troglodytes Troglodytes) to humans distinguishes pandemic HIV-1 group M strains from non-pandemic group N, O and P viruses and may have been a prerequisite for their global spread. Some functional motifs in the cytoplasmic region of HIV-1 M Vpus proposed to be important for anti-tetherin activity are more frequently found in the Vpu proteins of SIVcpzPtt than in those of SIVcpzPts infecting eastern chimpanzees (P. t. schweinfurthii), that have not been detected in humans, and SIVgor from gorillas, which is closely related to HIV-1 O and P. Thus, SIVcpzPtt strains may require fewer adaptive changes in Vpu than SIVcpzPts or SIVgor strains to counteract human tetherin.
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Phylogénie des SIV et des VIH - Mieux comprendre l’origine des VIH
Medecine sciences : M S, 2008Co-Authors: Martine Peeters, Marie-laure Chaix, Eric DelaporteAbstract:Emergence of human immunodeficiency viruses HIV-1 and HIV-2 results from interspecies transmission from simian viruses SIV. SIVcpzPtt infecting chimpanzees, and from which the HIV-1 (subgroups M and N) is derived is still found in the Pan Troglodytes Troglodytes population of south Cameroon chimpanzees. The ancestor of HIV-1 group O, is found in the Gorilla residing in Western Africa, but chimpanzees are in fact the initial reservoir of the SIV viruses SIVgor, and it is still unclear whether the group O HIV-1 has been transmitted to humans by gorillas and/or chimpanzees. At least eight interspecies transmissions between and humans implicating SIVsmm (from sooty mangabey monkeys) have occurred, corresponding to the eight VIH-2 groups. Since habits of hunting and meat preparation in the bush still persistently expose humans in Africa to SIV infection, new interspecies transmission of these viruses remains a possibility.
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The origins of HIV and implications for the global epidemic.
Current infectious disease reports, 2007Co-Authors: Fran Van Heuverswyn, Martine PeetersAbstract:HIV type 1 (HIV-1) and type 2 (HIV-2) are the result of several cross-species transmissions from primates to humans. Recently, the ancestral strains of HIV-1 groups M and N were shown to still persist in today’s wild chimpanzee populations (Pan Troglodytes Troglodytes) in south Cameroon. Lately, HIV-1 group O-related viruses have been identified in western gorillas (Gorilla gorilla), called SIVgor, but chimpanzees are most likely the original reservoir of this simian immunodeficiency virus (SIV) infection. HIV-2 is the result of at least eight distinct cross-species transmissions of SIV from sooty mangabeys (Cercocebus atys) in West Africa. Although the origin of HIV-1 and HIV-2 became clearer, some important questions concerning pathogenicity and epidemic spread of certain HIV/SIV variants need to be further elucidated. Because humans are still exposed to a plethora of primate lentiviruses through hunting and handling of primate bushmeat, the possibility of additional zoonotic transfers of primate lentiviruses from other primates must be considered.
Thierry Aubin - One of the best experts on this subject based on the ideXlab platform.
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When neighbours are not ‘dear enemies’: a study in the winter wren, Troglodytes Troglodytes
Animal Behaviour, 2014Co-Authors: Hélène Courvoisier, Sol Camacho-schlenker, Thierry AubinAbstract:Owing to the cost of territorial behaviour, territorial animals are able to adjust and modulate the intensity of their response according to their own condition and to the identity of the intruder. In birds, when neighbouring territorial males are well established, they often show a less intense response towards known neighbours than towards stranger conspecific males, a phenomenon known as the ‘dear enemy’ effect. Through playback experiments performed at the beginning, the middle and the end of the breeding season, we showed that winter wren males were able to discriminate neighbour versus stranger territorial songs despite a partial sharing of syllable repertoire. Surprisingly, males showed a stronger response to neighbours at the beginning of the breeding season and reacted as strongly to neighbour and stranger songs afterwards even if they lived in groups of stable and well-established neighbours. This suggests that neighbours can be as threatening as strangers, probably in both contexts of territorial occupancy and mate attraction, and that interactions between neighbours may depend on multiple factors including ecological constraints, past experiences and mating systems.
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Song sharing and singing strategies in the winter wren Troglodytes Troglodytes.
Behavioural processes, 2011Co-Authors: Sol Camacho-schlenker, Hélène Courvoisier, Thierry AubinAbstract:The winter wren is a common forest bird living in groups of few adjacent neighbours during the breeding season. Inside each group, males vocally interact in the context of both territorial holding and sexual competition, forming a complex communication network. To study this network, we first analysed song type and syllable repertoires within and between distinct groups. We found a limited number of song types highly stereotyped in length, syntax and syllable composition, frequently shared among neighbours. Between groups, song type and syllable repertoires sharing decreased with increasing distance at a higher rate for song types than for syllables. Then, with continuous recordings, we focused on the dynamics of acoustic interactions between neighbours. We showed that male winter wrens can differentially use their song type repertoire (non-matching strategy), overlap their neighbours and modulate their singing rhythm producing longer inter-song intervals with no change in song length during acoustic interactions.
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Song Degradation during Propagation: Importance of Song Post for the Wren Troglodytes Troglodytes
Ethology, 2010Co-Authors: Nicolas Mathevon, Thierry Aubin, Torben DabelsteenAbstract:The degradation of bird sounds during long-range propagation depends on different parameters such as density of vegetation, height from the ground and atmospheric perturbations. We investigated whether the wren Troglodytes Troglodytes, a bird species which has a high-pitched song that is very susceptible to degradation and lives in an environment that is very restricting for sound propagation, has any advantage in choosing relatively high song posts. Song degradation was investigated by analysing sound attenuation, duration of notes and silences, spectrum composition, modifications of frequency-modulated notes and amplitude fluctuations. Our data show that the choice of an elevated song post improves the reliability of all song parameters and increases the propagation distance of the song. It also improves the male wren's ability to hear opponent songs. The results are discussed from an ecological point of view.
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Reaction to conspecific degraded song by the wren Troglodytes Troglodytes: Territorial response and choice of song post.
Behavioural Processes, 1998Co-Authors: Nicolas Mathevon, Thierry AubinAbstract:Abstract We investigated the response of the wren Troglodytes Troglodytes to playback of a territorial song degraded by long-range propagation. It appears that the wren is sensitive to this degradation since the territorial reaction is less intense with the degraded song than with the undegraded one. However, the degraded song is still considered by the receiver as a specific territorial aggressive signal. This differential response suggests that the male wren can use the degradation characteristics of the signal to adapt its territorial reaction. Indeed, in response to this stimulus, the receiver wren chooses a higher song post. By so doing, the bird improves both the propagation distance of the emitted song and the receiver's ability to hear the opponent's song. This behavioural change may correspond to a communication strategy, counteracting the environmental constraints on sound propagation. Therefore, in response to sound degradation during long-range propagation, birds may have developed behavioural adaptations complementary to the various adaptations concerning song structure and coding-decoding processes.
Maria Makuwa - One of the best experts on this subject based on the ideXlab platform.
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New strain of simian immunodeficiency virus identified in wild-born chimpanzees from central Africa.
PLoS ONE, 2012Co-Authors: Sandrine Souquière, Maria Makuwa, Bettina Sallé, Mirdad KazanjiAbstract:Studies of primate lentiviruses continue to provide information about the evolution of simian immunodeficiency viruses (SIVs) and the origin and emergence of HIV since chimpanzees in west-central Africa (Pan Troglodytes Troglodytes) were recognized as the reservoir of SIVcpzPtt viruses, which have been related phylogenetically to HIV-1. Using in-house peptide ELISAs to study SIV prevalence, we tested 104 wild-born captive chimpanzees from Gabon and Congo. We identified two new cases of SIVcpz infection in Gabon and characterized a new SIVcpz strain, SIVcpzPtt-Gab4. The complete sequence (9093 bp) was obtained by a PCR-based 'genome walking' approach to generate 17 overlapping fragments. Phylogenetic analyses of separated genes (gag, pol-vif and env-nef) showed that SIVcpzPtt-Gab4 is closely related to SIVcpzPtt-Gab1 and SIVcpzPtt-Gab2. No significant variation in viral load was observed during 3 years of follow-up, but a significantly lower CD4+ T cells count was found in infected than in uninfected chimpanzees (p
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Identification of hepatitis B virus genome in faecal sample from wild living chimpanzee (Pan Troglodytes Troglodytes) in Gabon.
Journal of Clinical Virology, 2005Co-Authors: Maria Makuwa, Elizabeth J. Wickings, Sandrine Souquière, Stephen L. Clifford, Augustin Mouinga-ondémé, Mireille Bawe-johnson, François Simon, Sylvain Latour, Pierre RoquesAbstract:Abstract Non-invasive faecal sampling in the equatorial forest in Gabon allowed the first identification of the hepatitis B virus (HBV-Ch RC170 ) genome in samples collected from wild chimpanzees ( Pan Troglodytes Troglodytes ). The HBV-Ch RCl70 sequence clustered with 100% bootstrap support with previous viral sequences obtained from Pan Troglodytes subspecies. This is the first evidence of HBV infection in wild apes and confirms that the HBV-like strains thus far characterized in captive apes are directly related to those circulating in the wild.
Sandrine Souquière - One of the best experts on this subject based on the ideXlab platform.
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New strain of simian immunodeficiency virus identified in wild-born chimpanzees from central Africa.
PLoS ONE, 2012Co-Authors: Sandrine Souquière, Maria Makuwa, Bettina Sallé, Mirdad KazanjiAbstract:Studies of primate lentiviruses continue to provide information about the evolution of simian immunodeficiency viruses (SIVs) and the origin and emergence of HIV since chimpanzees in west-central Africa (Pan Troglodytes Troglodytes) were recognized as the reservoir of SIVcpzPtt viruses, which have been related phylogenetically to HIV-1. Using in-house peptide ELISAs to study SIV prevalence, we tested 104 wild-born captive chimpanzees from Gabon and Congo. We identified two new cases of SIVcpz infection in Gabon and characterized a new SIVcpz strain, SIVcpzPtt-Gab4. The complete sequence (9093 bp) was obtained by a PCR-based 'genome walking' approach to generate 17 overlapping fragments. Phylogenetic analyses of separated genes (gag, pol-vif and env-nef) showed that SIVcpzPtt-Gab4 is closely related to SIVcpzPtt-Gab1 and SIVcpzPtt-Gab2. No significant variation in viral load was observed during 3 years of follow-up, but a significantly lower CD4+ T cells count was found in infected than in uninfected chimpanzees (p
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Identification of hepatitis B virus genome in faecal sample from wild living chimpanzee (Pan Troglodytes Troglodytes) in Gabon.
Journal of Clinical Virology, 2005Co-Authors: Maria Makuwa, Elizabeth J. Wickings, Sandrine Souquière, Stephen L. Clifford, Augustin Mouinga-ondémé, Mireille Bawe-johnson, François Simon, Sylvain Latour, Pierre RoquesAbstract:Abstract Non-invasive faecal sampling in the equatorial forest in Gabon allowed the first identification of the hepatitis B virus (HBV-Ch RC170 ) genome in samples collected from wild chimpanzees ( Pan Troglodytes Troglodytes ). The HBV-Ch RCl70 sequence clustered with 100% bootstrap support with previous viral sequences obtained from Pan Troglodytes subspecies. This is the first evidence of HBV infection in wild apes and confirms that the HBV-like strains thus far characterized in captive apes are directly related to those circulating in the wild.
