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1.
Virology ; 585: 42-60, 2023 08.
Artículo en Inglés | MEDLINE | ID: mdl-37276766

RESUMEN

Rodentia is the most speciose order of mammals, and they are known to harbor a wide range of viruses. Although there has been significant research on zoonotic viruses in rodents, research on the diversity of other viruses has been limited, especially for rodents in the families Cricetidae and Heteromyidae. In fecal and liver samples of nine species of rodents, we identify 346 distinct circular DNA viral genomes. Of these, a large portion are circular, single-stranded DNA viruses in the families Anelloviridae (n = 3), Circoviridae (n = 5), Genomoviridae (n = 7), Microviridae (n = 297), Naryaviridae (n = 4), Vilyaviridae (n = 15) and in the phylum Cressdnaviricota (n = 13) that cannot be assigned established families. We also identified two large bacteriophages of 36 and 50 kb that are part of the class Caudoviricetes. Some of these viruses are clearly those that infect rodents, however, most of these likely infect various organisms associated with rodents, their environment or their diet.


Asunto(s)
Roedores , Virus , Animales , Filogenia , Virus ADN/genética , Virus/genética , Mamíferos , Genoma Viral
2.
Vet Sci ; 10(6)2023 May 31.
Artículo en Inglés | MEDLINE | ID: mdl-37368768

RESUMEN

The COVID-19 pandemic has led to millions of human infections and deaths worldwide. Several other mammal species are also susceptible to SARS-CoV-2, and multiple instances of transmission from humans to pets, farmed mink, wildlife and zoo animals have been recorded. We conducted a systematic surveillance of SARS-CoV-2 in all mammal species in two zoos in Belgium between September and December 2020 and July 2021, in four sessions, and a targeted surveillance of selected mammal enclosures following SARS-CoV-2 infection in hippopotamuses in December 2021. A total of 1523 faecal samples from 103 mammal species were tested for SARS-CoV-2 via real-time PCR. None of the samples tested positive for SARS-CoV-2. Additional surrogate virus neutralisation tests conducted on 50 routinely collected serum samples from 26 mammal species were all negative. This study is the first to our knowledge to conduct active SARS-CoV-2 surveillance for several months in all mammal species of a zoo. We conclude that at the time of our investigation, none of the screened animals were excreting SARS-CoV-2.

3.
Virology ; 581: 116-127, 2023 04.
Artículo en Inglés | MEDLINE | ID: mdl-36958216

RESUMEN

Mastomys natalensis-borne mammarenaviruses appear specific to subspecific M. natalensis taxa rather than to the whole species. Yet mammarenaviruses carried by M. natalensis are known to spill over and jump hosts in northern sub-Saharan Africa. Phylogeographic studies increasingly show that, like M. natalensis, small mammals in sub-Saharan Africa are often genetically structured into several subspecific taxa. Other mammarenaviruses may thus also form virus-subspecific host taxon associations. To investigate this, and if mammarenaviruses carried by M. natalensis in southern Africa are less prone to spill-over, we screened 1225 non-M. natalensis samples from Tanzania where many small mammal taxa meet. We found mammarenavirus RNA in 6 samples. Genetic/genomic characterisation confirmed they were not spill-over from M. natalensis. We detected host jumps among rodent tribe members and an association between mammarenaviruses and subspecific taxa of Mus minutoides and Grammomys surdaster, indicating host genetic structure may be crucial to understand virus distribution and host specificity.


Asunto(s)
Arenaviridae , Enfermedades de los Roedores , Animales , Arenaviridae/genética , Especificidad del Huésped , Murinae , Filogeografía , Tanzanía
4.
Animals (Basel) ; 13(2)2023 Jan 16.
Artículo en Inglés | MEDLINE | ID: mdl-36670856

RESUMEN

Two adult female hippos in Zoo Antwerp who were naturally infected with SARS-CoV-2 showed nasal discharge for a few days. Virus was detected by immunocytochemistry and PCR in nasal swab samples and by PCR in faeces and pool water. Serology was also positive. No treatment was necessary.

5.
Mol Biol Evol ; 39(10)2022 10 07.
Artículo en Inglés | MEDLINE | ID: mdl-36063436

RESUMEN

As viral genomic imprints in host genomes, endogenous viral elements (EVEs) shed light on the deep evolutionary history of viruses, ancestral host ranges, and ancient viral-host interactions. In addition, they may provide crucial information for calibrating viral evolutionary timescales. In this study, we conducted a comprehensive in silico screening of a large data set of available mammalian genomes for EVEs deriving from members of the viral family Flaviviridae, an important group of viruses including well-known human pathogens, such as Zika, dengue, or hepatitis C viruses. We identified two novel pestivirus-like EVEs in the reference genome of the Indochinese shrew (Crocidura indochinensis). Homologs of these novel EVEs were subsequently detected in vivo by molecular detection and sequencing in 27 shrew species, including 26 species representing a wide distribution within the Crocidurinae subfamily and one in the Soricinae subfamily on different continents. Based on this wide distribution, we estimate that the integration event occurred before the last common ancestor of the subfamily, about 10.8 million years ago, attesting to an ancient origin of pestiviruses and Flaviviridae in general. Moreover, we provide the first description of Flaviviridae-derived EVEs in mammals even though the family encompasses numerous mammal-infecting members. This also suggests that shrews were past and perhaps also current natural reservoirs of pestiviruses. Taken together, our results expand the current known Pestivirus host range and provide novel insight into the ancient evolutionary history of pestiviruses and the Flaviviridae family in general.


Asunto(s)
Pestivirus , Virus , Infección por el Virus Zika , Virus Zika , Animales , Evolución Molecular , Genoma Viral , Humanos , Pestivirus/genética , Filogenia , Musarañas/genética , Virus/genética , Virus Zika/genética
6.
PLoS Negl Trop Dis ; 16(9): e0010757, 2022 09.
Artículo en Inglés | MEDLINE | ID: mdl-36112668

RESUMEN

Leptospirosis is a neglected zoonotic disease and one of the leading causes of zoonotic morbidity and mortality, particularly in resource-poor settings. Sri Lanka has one of the highest disease burdens worldwide, with occasional endemic leptospirosis outbreaks (2008, 2011). Rodents are considered the main wildlife reservoir, but due to a scarcity of studies it is unclear which particular species contributes to bacterial transmission and reservoir maintenance in this multi-host multi-parasite system. Several rodent species act as agricultural pests both in rice fields and in food storage facilities. To unravel the interactions among the small mammal communities, pathogenic Leptospira spp. and human transmission pathways, we collected animals from smallholder food storage facilities, where contact between humans and small mammals is most likely, and screened kidney tissue samples for Leptospira spp. using PCR. Samples were collected in three climatic zones along a rainfall gradient. Pathogenic Leptospira spp. were detected in small mammal communities in 37 (74%) out of 50 sampled farms and 61 (12%) out of 500 collected individuals were infected. The small mammal community was comprised of Rattus rattus (87.6%), Suncus shrews (8.8%), Bandicota spp. (2.8%) and Mus booduga (0.8%). Three pathogenic Leptospira spp. were identified, L. borgpetersenii (n = 34), L. interrogans (n = 15), and L. kirschneri (n = 1). Suncus shrews were commonly infected (32%), followed by B. indica (23%) and R. rattus (10%). L. borgpetersenii strains similar to strains previously extracted from human clinal samples in Sri Lanka were detected in R. rattus and Suncus shrews. L. interrogans was observed in R. rattus only. A single L. kirschneri infection was found in M. booduga. The presence of human pathogenic Leptospira species in an agricultural pest rodent (R. rattus) and in commensal shrews (Suncus) calls for management of these species in commensal settings. Further investigation of the interplay between pathogen and reservoir population dynamics, overlap in geographic range and the extent of spill-over to humans in and around rural settlements is required to identify optimal management approaches.


Asunto(s)
Leptospira , Leptospirosis , Enfermedades de los Roedores , Animales , Humanos , Leptospira/genética , Leptospirosis/epidemiología , Leptospirosis/microbiología , Leptospirosis/veterinaria , Ratones , Ratas , Enfermedades de los Roedores/epidemiología , Roedores/microbiología , Musarañas/microbiología , Sri Lanka/epidemiología
7.
Nat Commun ; 13(1): 5596, 2022 09 27.
Artículo en Inglés | MEDLINE | ID: mdl-36167835

RESUMEN

Lassa fever is a severe viral hemorrhagic fever caused by a zoonotic virus that repeatedly spills over to humans from its rodent reservoirs. It is currently not known how climate and land use changes could affect the endemic area of this virus, currently limited to parts of West Africa. By exploring the environmental data associated with virus occurrence using ecological niche modelling, we show how temperature, precipitation and the presence of pastures determine ecological suitability for virus circulation. Based on projections of climate, land use, and population changes, we find that regions in Central and East Africa will likely become suitable for Lassa virus over the next decades and estimate that the total population living in ecological conditions that are suitable for Lassa virus circulation may drastically increase by 2070. By analysing geotagged viral genomes using spatially-explicit phylogeography and simulating virus dispersal, we find that in the event of Lassa virus being introduced into a new suitable region, its spread might remain spatially limited over the first decades.


Asunto(s)
Fiebre de Lassa , Virus Lassa , Animales , Humanos , Fiebre de Lassa/epidemiología , Virus Lassa/genética , Filogeografía , Factores de Riesgo , Roedores
8.
Arch Virol ; 167(12): 2771-2775, 2022 Dec.
Artículo en Inglés | MEDLINE | ID: mdl-36045303

RESUMEN

Bats harbour a diverse array of viruses, some of which are zoonotic, and are one of the most speciose groups of mammals on earth. As part of an ongoing bat-associated viral diversity research project, we identified three cycloviruses (family Circoviridae) in fecal samples of silver-haired bats (Lasionycteris noctivagans) caught in Cave Creek Canyon of Arizona (USA). Two of the three identified genomes represent two new species in the genus Cyclovirus. Cycloviruses have been found in a wide range of environments and hosts; however, little is known about their biology. These new genomes of cycloviruses are the first from silver-haired bats, adding to the broader knowledge of cyclovirus diversity. With continuing studies, it is likely that additional viruses of the family Circoviridae will be identified in Arizona bat populations.


Asunto(s)
Quirópteros , Circoviridae , Animales , Heces , Arizona
9.
mBio ; 13(2): e0005422, 2022 04 26.
Artículo en Inglés | MEDLINE | ID: mdl-35311536

RESUMEN

Upon infection, DNA viruses can be sensed by pattern recognition receptors (PRRs), leading to the activation of type I and III interferons to block infection. Therefore, viruses must inhibit these signaling pathways, avoid being detected, or both. Papillomavirus virions are trafficked from early endosomes to the Golgi apparatus and wait for the onset of mitosis to complete nuclear entry. This unique subcellular trafficking strategy avoids detection by cytoplasmic PRRs, a property that may contribute to the establishment of infection. However, as the capsid uncoats within acidic endosomal compartments, the viral DNA may be exposed to detection by Toll-like receptor 9 (TLR9). In this study, we characterized two new papillomaviruses from bats and used molecular archeology to demonstrate that their genomes altered their nucleotide compositions to avoid detection by TLR9, providing evidence that TLR9 acts as a PRR during papillomavirus infection. Furthermore, we showed that TLR9, like other components of the innate immune system, is under evolutionary selection in bats, providing the first direct evidence for coevolution between papillomaviruses and their hosts. Finally, we demonstrated that the cancer-associated human papillomaviruses show a reduction in CpG dinucleotides within a TLR9 recognition complex. IMPORTANCE Viruses must avoid detection by the innate immune system. In this study, we characterized two new papillomaviruses from bats and used molecular archeology to demonstrate that their genomes altered their nucleotide compositions to avoid detection by TLR9, providing evidence that TLR9 acts as a PRR during papillomavirus infection. Furthermore, we demonstrated that TLR9, like other components of the innate immune system, is under evolutionary selection in bats, providing the first direct evidence for coevolution between papillomaviruses and their hosts.


Asunto(s)
Infecciones por Papillomavirus , Virosis , Virus , Humanos , Nucleótidos , Papillomaviridae/genética , Papillomaviridae/metabolismo , Receptores de Reconocimiento de Patrones , Receptor Toll-Like 9/genética
10.
Transbound Emerg Dis ; 69(5): 3016-3021, 2022 Sep.
Artículo en Inglés | MEDLINE | ID: mdl-34224205

RESUMEN

SARS-CoV-2 human-to-animal transmission can lead to the establishment of novel reservoirs and the evolution of new variants with the potential to start new outbreaks in humans. We tested Norway rats inhabiting the sewer system of Antwerp, Belgium, for the presence of SARS-CoV-2 following a local COVID-19 epidemic peak. In addition, we discuss the use and interpretation of SARS-CoV-2 serological tests on non-human samples. Between November and December 2020, Norway rat oral swabs, faeces and tissues from the sewer system of Antwerp were collected to be tested by RT-qPCR for the presence of SARS-CoV-2. Serum samples were screened for the presence of anti-SARS-CoV-2 IgG antibodies using a Luminex microsphere immunoassay (MIA). Samples considered positive were then checked for neutralizing antibodies using a conventional viral neutralization test (cVNT). The serum of 35 rats was tested by MIA showing three potentially positive sera that were later negative by cVNT. All tissue samples of 39 rats analysed tested negative for SARS-CoV-2 RNA. This is the first study that evaluates SARS-CoV-2 infection in urban rats. We can conclude that the sample of rats analysed had never been infected with SARS-CoV-2. However, monitoring activities should continue due to the emergence of new variants prone to infect Muridae rodents.


Asunto(s)
COVID-19 , Enfermedades de los Roedores , Animales , Anticuerpos Neutralizantes , Anticuerpos Antivirales , Bélgica/epidemiología , COVID-19/epidemiología , COVID-19/veterinaria , Inmunoglobulina G , ARN Viral , Ratas , Enfermedades de los Roedores/epidemiología , SARS-CoV-2
11.
J Virol ; 96(3): e0109821, 2022 02 09.
Artículo en Inglés | MEDLINE | ID: mdl-34668771

RESUMEN

Paramyxoviruses are a diverse group of negative-sense, single-stranded RNA viruses of which several species cause significant mortality and morbidity. In recent years the collection of paramyxovirus sequences detected in wild mammals has substantially grown; however, little is known about paramyxovirus diversity in North American mammals. To better understand natural paramyxovirus diversity, host range, and host specificity, we sought to comprehensively characterize paramyxoviruses across a range of diverse cooccurring wild small mammals in southern Arizona. We used highly degenerate primers to screen fecal and urine samples and obtained a total of 55 paramyxovirus sequences from 12 rodent species and 6 bat species. We also performed Illumina transcriptome sequencing (RNA-seq) and de novo assembly on 14 of the positive samples to recover a total of 5 near-full-length viral genomes. We show there are at least two clades of rodent-borne paramyxoviruses in Arizona, while bat-associated paramyxoviruses formed a putative single clade. Using structural homology modeling of the viral attachment protein, we infer that three of the five novel viruses likely bind sialic acid in a manner similar to other respiroviruses, while the other two viruses from heteromyid rodents likely bind a novel host receptor. We find no evidence for cross-species transmission, even among closely related sympatric host species. Taken together, these data suggest paramyxoviruses are a common viral infection in some bat and rodent species present in North America and illuminate the evolution of these viruses. IMPORTANCE There are a number of viral lineages that are potential zoonotic threats to humans. One of these, paramyxoviruses have jumped into humans multiple times from wild and domestic animals. We conducted one of the largest viral surveys of wild mammals in the United States to better understand paramyxovirus diversity and evolution.


Asunto(s)
Enfermedades de los Animales/epidemiología , Enfermedades de los Animales/virología , Quirópteros/virología , Infecciones por Paramyxoviridae/veterinaria , Paramyxoviridae/clasificación , Paramyxoviridae/genética , Secuencia de Aminoácidos , Enfermedades de los Animales/diagnóstico , Animales , Arizona/epidemiología , Biodiversidad , Evolución Biológica , Genoma Viral , Genómica/métodos , Geografía Médica , Secuenciación de Nucleótidos de Alto Rendimiento , Especificidad del Huésped , Humanos , Modelos Moleculares , Técnicas de Diagnóstico Molecular/métodos , América del Norte/epidemiología , Filogenia , Unión Proteica , ARN Viral , Receptores Virales/química , Receptores Virales/metabolismo , Respirovirus/clasificación , Respirovirus/genética , Infecciones por Respirovirus/veterinaria , Roedores/virología
12.
Viruses ; 13(9)2021 09 15.
Artículo en Inglés | MEDLINE | ID: mdl-34578423

RESUMEN

Recent years have witnessed the discovery of several new viruses belonging to the family Arteriviridae, expanding the known diversity and host range of this group of complex RNA viruses. Although the pathological relevance of these new viruses is not always clear, several well-studied members of the family Arteriviridae are known to be important animal pathogens. Here, we report the complete genome sequences of four new arterivirus variants, belonging to two putative novel species. These new arteriviruses were discovered in African rodents and were given the names Lopma virus and Praja virus. Their genomes follow the characteristic genome organization of all known arteriviruses, even though they are only distantly related to currently known rodent-borne arteriviruses. Phylogenetic analysis shows that Lopma virus clusters in the subfamily Variarterivirinae, while Praja virus clusters near members of the subfamily Heroarterivirinae: the yet undescribed forest pouched giant rat arterivirus and hedgehog arterivirus 1. A co-divergence analysis of rodent-borne arteriviruses confirms that they share similar phylogenetic patterns with their hosts, with only very few cases of host shifting events throughout their evolutionary history. Overall, the genomes described here and their unique clustering with other arteriviruses further illustrate the existence of multiple rodent-borne arterivirus lineages, expanding our knowledge of the evolutionary origin of these viruses.


Asunto(s)
Arteriviridae/genética , Genoma Viral , Infecciones por Virus ARN/veterinaria , Enfermedades de los Roedores/virología , Roedores/virología , África del Sur del Sahara , Animales , Arteriviridae/clasificación , Arteriviridae/aislamiento & purificación , Evolución Biológica , Secuenciación de Nucleótidos de Alto Rendimiento , Filogenia , Infecciones por Virus ARN/virología , Secuenciación Completa del Genoma
13.
Virus Evol ; 7(1): veab036, 2021 Jan.
Artículo en Inglés | MEDLINE | ID: mdl-34221451

RESUMEN

Hepatitis C virus (HCV; genus Hepacivirus) represents a major public health problem, infecting about three per cent of the human population. Because no animal reservoir carrying closely related hepaciviruses has been identified, the zoonotic origins of HCV still remain unresolved. Motivated by recent findings of divergent hepaciviruses in rodents and a plausible African origin of HCV genotypes, we have screened a large collection of small mammals samples from seven sub-Saharan African countries. Out of 4,303 samples screened, eighty were found positive for the presence of hepaciviruses in twenty-nine different host species. We, here, report fifty-six novel genomes that considerably increase the diversity of three divergent rodent hepacivirus lineages. Furthermore, we provide strong evidence for hepacivirus co-infections in rodents, which were exclusively found in four sampled species of brush-furred mice. We also detect evidence of recombination within specific host lineages. Our study expands the available hepacivirus genomic data and contributes insights into the relatively deep evolutionary history of these pathogens in rodents. Overall, our results emphasize the importance of rodents as a potential hepacivirus reservoir and as models for investigating HCV infection dynamics.

14.
Mamm Rev ; 51(2): 272-292, 2021 Apr.
Artículo en Inglés | MEDLINE | ID: mdl-33230363

RESUMEN

It has been a long time since the world has experienced a pandemic with such a rapid devastating impact as the current COVID-19 pandemic. The causative agent, severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2), is unusual in that it appears capable of infecting many different mammal species. As a significant proportion of people worldwide are infected with SARS-CoV-2 and may spread the infection unknowingly before symptoms occur or without any symptoms ever occurring, there is a non-negligible risk of humans spreading SARS-CoV-2 to wildlife, in particular to wild non-human mammals. Because of SARS-CoV-2's apparent evolutionary origins in bats and reports of humans transmitting the virus to pets and zoo animals, regulations for the prevention of human-to-animal transmission have so far focused mostly on these animal groups. We summarise recent studies and reports that show that a wide range of distantly related mammals are likely to be susceptible to SARS-CoV-2, and that susceptibility or resistance to the virus is, in general, not predictable, or only predictable to some extent, from phylogenetic proximity to known susceptible or resistant hosts. In the absence of solid evidence on the susceptibility and resistance to SARS-CoV-2 for each of the >6500 mammal species, we argue that sanitary precautions should be taken by humans interacting with any other mammal species in the wild. Preventing human-to-wildlife SARS-CoV-2 transmission is important to protect these animals (some of which are classed as threatened) from disease, but also to avoid establishment of novel SARS-CoV-2 reservoirs in wild mammals. The risk of repeated re-infection of humans from such a wildlife reservoir could severely hamper SARS-CoV-2 control efforts. Activities during which direct or indirect interaction with wild mammals may occur include wildlife research, conservation activities, forestry work, pest control, management of feral populations, ecological consultancy work, management of protected areas and natural environments, wildlife tourism and wildlife rehabilitation in animal shelters. During such activities, we recommend sanitary precautions, such as physical distancing, wearing face masks and gloves, and frequent decontamination, which are very similar to regulations currently imposed to prevent transmission among humans. We further recommend active surveillance of domestic and feral animals that could act as SARS-CoV-2 intermediate hosts between humans and wild mammals.

15.
Virus Evol ; 6(2): veaa039, 2020 Jul.
Artículo en Inglés | MEDLINE | ID: mdl-33033629

RESUMEN

Mastomys natalensis is widespread in sub-Saharan Africa and hosts several arenavirus species, including the pathogenic zoonotic Lassa virus in West Africa. Mitochondrial lineages sub-divide the range of M. natalensis and have been associated with cryptic structure within the species. To test specificity of arenaviruses to hosts carrying these lineages, we screened 1772 M. natalensis in a large area of Tanzania where three mitochondrial lineages meet. We detected fifty-two individuals that were positive for one of three arenaviruses: Gairo, Morogoro, and Luna virus. This is the first record of Luna virus in Tanzania. We confirmed the specificity of each arenavirus to a distinct host mitochondrial lineage except for three cases in one locality at the centre of a host hybrid zone. No arenaviruses were detected in a large part of the study area. Morogoro and Gairo virus showed differences in prevalence (Morogoro virus lower than Gairo virus) and in genetic structure (Morogoro virus more structured than Gairo virus). However, both viruses have genetic neighbourhood size estimates of the same order of magnitude as Lassa virus. While differences in arenavirus and/or host evolutionary and ecological dynamics may exist, Tanzanian arenaviruses could be suited to model Lassa virus dynamics in M. natalensis.

16.
Emerg Infect Dis ; 26(9): 2205-2209, 2020 09.
Artículo en Inglés | MEDLINE | ID: mdl-32818404

RESUMEN

After the 2017 Ebola virus (EBOV) outbreak in Likati, a district in northern Democratic Republic of the Congo, we sampled small mammals from the location where the primary case-patient presumably acquired the infection. None tested positive for EBOV RNA or antibodies against EBOV, highlighting the ongoing challenge in detecting animal reservoirs for EBOV.


Asunto(s)
Ebolavirus , Fiebre Hemorrágica Ebola , Animales , Animales Salvajes , República Democrática del Congo/epidemiología , Brotes de Enfermedades , Ebolavirus/genética , Fiebre Hemorrágica Ebola/epidemiología , Humanos
17.
Proc Natl Acad Sci U S A ; 117(22): 12222-12229, 2020 06 02.
Artículo en Inglés | MEDLINE | ID: mdl-32430331

RESUMEN

With very little direct biological data of HIV-1 from before the 1980s, far-reaching evolutionary and epidemiological inferences regarding the long prediscovery phase of this pandemic are based on extrapolations by phylodynamic models of HIV-1 genomic sequences gathered mostly over recent decades. Here, using a very sensitive multiplex RT-PCR assay, we screened 1,645 formalin-fixed paraffin-embedded tissue specimens collected for pathology diagnostics in Central Africa between 1958 and 1966. We report the near-complete viral genome in one HIV-1 positive specimen from Kinshasa, Democratic Republic of Congo (DRC), from 1966 ("DRC66")-a nonrecombinant sister lineage to subtype C that constitutes the oldest HIV-1 near full-length genome recovered to date. Root-to-tip plots showed the DRC66 sequence is not an outlier as would be expected if dating estimates from more recent genomes were systematically biased; and inclusion of the DRC66 sequence in tip-dated BEAST analyses did not significantly alter root and internal node age estimates based on post-1978 HIV-1 sequences. There was larger variation in divergence time estimates among datasets that were subsamples of the available HIV-1 genomes from 1978 to 2014, showing the inherent phylogenetic stochasticity across subsets of the real HIV-1 diversity. Our phylogenetic analyses date the origin of the pandemic lineage of HIV-1 to a time period around the turn of the 20th century (1881 to 1918). In conclusion, this unique archival HIV-1 sequence provides direct genomic insight into HIV-1 in 1960s DRC, and, as an ancient-DNA calibrator, it validates our understanding of HIV-1 evolutionary history.


Asunto(s)
Linaje de la Célula/genética , Evolución Molecular , Variación Genética , Genoma Viral , Infecciones por VIH/genética , VIH-1/genética , Adhesión en Parafina/métodos , Adulto , República Democrática del Congo , Infecciones por VIH/virología , Humanos , Masculino , Filogenia , Análisis de Secuencia de ADN , Factores de Tiempo
18.
J Anim Ecol ; 89(2): 506-518, 2020 02.
Artículo en Inglés | MEDLINE | ID: mdl-31545505

RESUMEN

A key aim in wildlife disease ecology is to understand how host and parasite characteristics influence parasite transmission and persistence. Variation in host population density can have strong impacts on transmission and outbreaks, and theory predicts particular transmission-density patterns depending on how parasites are transmitted between individuals. Here, we present the results of a study on the dynamics of Morogoro arenavirus in a population of multimammate mice (Mastomys natalensis). This widespread African rodent, which is also the reservoir host of Lassa arenavirus in West Africa, is known for its strong seasonal density fluctuations driven by food availability. We investigated to what degree virus transmission changes with host population density and how the virus might be able to persist during periods of low host density. A seven-year capture-mark-recapture study was conducted in Tanzania where rodents were trapped monthly and screened for the presence of antibodies against Morogoro virus. Observed seasonal seroprevalence patterns were compared with those generated by mathematical transmission models to test different hypotheses regarding the degree of density dependence and the role of chronically infected individuals. We observed that Morogoro virus seroprevalence correlates positively with host density with a lag of 1-4 months. Model results suggest that the observed seasonal seroprevalence dynamics can be best explained by a combination of vertical and horizontal transmission and that a small number of animals need to be infected chronically to ensure viral persistence. Transmission dynamics and viral persistence were best explained by the existence of both acutely and chronically infected individuals and by seasonally changing transmission rates. Due to the presence of chronically infected rodents, rodent control is unlikely to be a feasible approach for eliminating arenaviruses such as Lassa virus from Mastomys populations.


Asunto(s)
Infecciones por Arenaviridae/epidemiología , Arenavirus/inmunología , Enfermedades de los Roedores/epidemiología , Animales , Anticuerpos Antivirales , Reservorios de Enfermedades/veterinaria , Ratones , Densidad de Población , Estudios Seroepidemiológicos , Tanzanía/epidemiología
19.
Virus Evol ; 5(2): vez036, 2019 Jul.
Artículo en Inglés | MEDLINE | ID: mdl-31720009

RESUMEN

The need to estimate divergence times in evolutionary histories in the presence of various sources of substitution rate variation has stimulated a rich development of relaxed molecular clock models. Viral evolutionary studies frequently adopt an uncorrelated clock model as a generic relaxed molecular clock process, but this may impose considerable estimation bias if discrete rate variation exists among clades or lineages. For HIV-1 group M, rate variation among subtypes has been shown to result in inconsistencies in time to the most recent common ancestor estimation. Although this calls into question the adequacy of available molecular dating methods, no solution to this problem has been offered so far. Here, we investigate the use of mixed effects molecular clock models, which combine both fixed and random effects in the evolutionary rate, to estimate divergence times. Using simulation, we demonstrate that this model outperforms existing molecular clock models in a Bayesian framework for estimating time-measured phylogenies in the presence of mixed sources of rate variation, while also maintaining good performance in simpler scenarios. By analysing a comprehensive HIV-1 group M complete genome data set we confirm considerable rate variation among subtypes that is not adequately modelled by uncorrelated relaxed clock models. The mixed effects clock model can accommodate this rate variation and results in a time to the most recent common ancestor of HIV-1 group M of 1920 (1915-25), which is only slightly earlier than the uncorrelated relaxed clock estimate for the same data set. The use of complete genome data appears to have a more profound impact than the molecular clock model because it reduces the credible intervals by 50 per cent relative to similar estimates based on short envelope gene sequences.

20.
BMC Genomics ; 19(1): 617, 2018 Aug 16.
Artículo en Inglés | MEDLINE | ID: mdl-30115009

RESUMEN

BACKGROUND: In the past decade, many new paramyxoviruses that do not belong to any of the seven established genera in the family Paramyxoviridae have been discovered. Amongst them are J-virus (JPV), Beilong virus (BeiPV) and Tailam virus (TlmPV), three paramyxovirus species found in rodents. Based on their similarities, it has been suggested that these viruses should compose a new genus, tentatively called 'Jeilongvirus'. RESULTS: Here we present the complete genomes of three newly discovered paramyxoviruses, one found in a bank vole (Myodes glareolus) from Slovenia and two in a single, co-infected Rungwe brush-furred rat (Lophuromys machangui) from Mozambique, that represent three new, separate species within the putative genus 'Jeilongvirus'. The genome organization of these viruses is similar to other paramyxoviruses, but like JPV, BeiPV and TlmPV, they possess an additional open reading frame, encoding a transmembrane protein, that is located between the F and G genes. As is the case for all Jeilongviruses, the G genes of the viruses described here are unusually large, and their encoded proteins are characterized by a remarkable amino acid composition pattern that is not seen in other paramyxoviruses, but resembles certain motifs found in Orthopneumovirus G proteins. CONCLUSIONS: The phylogenetic clustering of JPV, BeiPV and TlmPV with the viruses described here, as well as their shared features that set them apart from other paramyxoviruses, provide additional support for the recognition of the genus 'Jeilongvirus'.


Asunto(s)
Genoma Viral , Proteínas de la Membrana/genética , Paramyxovirinae/clasificación , Paramyxovirinae/genética , Proteínas Virales/genética , Secuencia de Aminoácidos , Animales , Clonación Molecular , Paramyxoviridae/clasificación , Paramyxoviridae/genética , Filogenia , Análisis de Secuencia de ADN
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