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1.
J Virol ; 97(1): e0145522, 2023 01 31.
Artigo em Inglês | MEDLINE | ID: mdl-36633410

RESUMO

Rotavirus A (RVA) causes diarrheal disease in humans and various animals. Recent studies have identified bat and rodent RVAs with evidence of zoonotic transmission and genome reassortment. However, the virological properties of bat and rodent RVAs with currently identified genotypes still need to be better clarified. Here, we performed virus isolation-based screening for RVA in animal specimens and isolated RVAs (representative strains: 16-06 and MpR12) from Egyptian fruit bat and Natal multimammate mouse collected in Zambia. Whole-genome sequencing and phylogenetic analysis revealed that the genotypes of bat RVA 16-06 were identical to that of RVA BATp39 strain from the Kenyan fruit bat, which has not yet been characterized. Moreover, all segments of rodent RVA MpR12 were highly divergent and assigned to novel genotypes, but RVA MpR12 was phylogenetically closer to bat RVAs than to other rodent RVAs, indicating a unique evolutionary history. We further investigated the virological properties of the isolated RVAs. In brief, we found that 16-06 entered cells by binding to sialic acids on the cell surface, while MpR12 entered in a sialic acid-independent manner. Experimental inoculation of suckling mice with 16-06 and MpR12 revealed that these RVAs are causative agents of diarrhea. Moreover, 16-06 and MpR12 demonstrated an ability to infect and replicate in a 3D-reconstructed primary human intestinal epithelium with comparable efficiency to the human RVA. Taken together, our results detail the unique genetic and virological features of bat and rodent RVAs and demonstrate the need for further investigation of their zoonotic potential. IMPORTANCE Recent advances in nucleotide sequence detection methods have enabled the detection of RVA genomes from various animals. These studies have discovered multiple divergent RVAs and have resulted in proposals for the genetic classification of novel genotypes. However, most of these RVAs have been identified via dsRNA viral genomes and not from infectious viruses, and their virological properties, such as cell/host tropisms, transmissibility, and pathogenicity, are unclear and remain to be clarified. Here, we successfully isolated RVAs with novel genome constellations from three bats and one rodent in Zambia. In addition to whole-genome sequencing, the isolated RVAs were characterized by glycan-binding affinity, pathogenicity in mice, and infectivity to the human gut using a 3D culture of primary intestinal epithelium. Our study reveals the first virological properties of bat and rodent RVAs with high genetic diversity and unique evolutional history and provides basic knowledge to begin estimating the potential of zoonotic transmission.


Assuntos
Quirópteros , Murinae , Infecções por Rotavirus , Rotavirus , Animais , Quirópteros/virologia , Diarreia/veterinária , Diarreia/virologia , Genoma Viral , Genótipo , Quênia , Filogenia , Rotavirus/genética , Rotavirus/isolamento & purificação , Infecções por Rotavirus/veterinária , Murinae/virologia
2.
BMC Microbiol ; 24(1): 351, 2024 Sep 17.
Artigo em Inglês | MEDLINE | ID: mdl-39289639

RESUMO

BACKGROUND: Bacillus cereus is a Gram-positive, spore-forming bacterium that produces a spectrum of effectors integral to bacterial niche adaptation and the development of various infections. Among those is EsxA, whose secretion depends on the EssC component of the type VII secretion system (T7SS). EsxA's roles within the bacterial cell are poorly understood, although postulations indicate that it may be involved in sporulation. However, the T7SS repertoire in B. cereus has not been reported, and its functions are unestablished. METHODS: We used the type strain, B. cereus ATCC14579, to generate ΔessC mutant through homologous recombination using the homing endonuclease I-SceI mediated markerless gene replacement. Comparatively, we analyzed the culture supernatant of type strain and the ΔessC mutant through Liquid chromatography-tandem mass spectrometry (LC-MS/MS). We further generated T7SSb-specific gene mutations to explore the housekeeping roles of the T7SSb-dependent effectors. The sporulation process of B. cereus ATCC14579 and its mutants was observed microscopically through the classic Schaeffer-Fulton staining method. The spore viability of each strain in this study was established by enumerating the colony-forming units on LB agar. RESULTS: Through LC-MS/MS, we identified a pair of nearly identical (94%) effector proteins named EsxA belonging to the sagEsxA-like subfamily of the WXG100 protein superfamily in the culture supernatant of the wild type and none in the ΔessC mutant. Homology analysis of the T7SSb gene cluster among B. cereus strains revealed diversity from the 3' end of essC, encoding additional substrates. Deletions in esxA1 and esxA2 neither altered cellular morphology nor growth rate, but the ΔesxA1ΔesxA2 deletion resulted in significantly fewer viable spores and an overall slower sporulation process. Within 24 h culture, more than 80% of wild-type cells formed endospores compared to less than 5% in the ΔesxA1ΔesxA2 mutant. The maximum spore ratios for the wild type and ΔesxA1ΔesxA2 were 0.96 and 0.72, respectively. Altogether, these results indicated that EsxA1 and EsxA2 work cooperatively and are required for sporulation in B. cereus ATCC14567. CONCLUSION: B. cereus ATCC14579 possesses two nearly identical T7SSb-dependent effectors belonging to the sagEsxA-like proteins. Simultaneous deletion of genes encoding these effectors significantly delayed and reduced sporulation, a novel finding for EsxA.


Assuntos
Bacillus cereus , Proteínas de Bactérias , Esporos Bacterianos , Sistemas de Secreção Tipo VII , Bacillus cereus/genética , Bacillus cereus/metabolismo , Bacillus cereus/fisiologia , Bacillus cereus/crescimento & desenvolvimento , Esporos Bacterianos/genética , Esporos Bacterianos/crescimento & desenvolvimento , Esporos Bacterianos/metabolismo , Proteínas de Bactérias/genética , Proteínas de Bactérias/metabolismo , Sistemas de Secreção Tipo VII/genética , Sistemas de Secreção Tipo VII/metabolismo , Espectrometria de Massas em Tandem , Mutação , Cromatografia Líquida
3.
Virol J ; 21(1): 263, 2024 Oct 24.
Artigo em Inglês | MEDLINE | ID: mdl-39449113

RESUMO

BACKGROUND: Rotavirus B (RVB) causes diarrhea in humans and pigs. Although various RVB strains were identified in humans and various animals globally, little is known about the epidemiology RVB infection in Africa. In this study, we attempted to examine the prevalence of RVB infection in pig populations in Zambia. METHODS: Metagenomic analyses were conducted on pig feces collected in Zambia to detect double stranded RNA viruses, including RVB. To clarify the prevalence of RVB infection in pig populations in Zambia, 147 fecal samples were screened for the RVB detection by RT-qPCR. Full genome sequence of a detected RVB was determined by Sanger sequencing and genetically analyzed. RESULTS: The metagenomic analyses revealed that RVB sequence reads and contigs of RVB were detected from one fecal sample collected from pigs in Zambia. RT-qPCR screening detected RVB genomes in 36.7% (54/147) of fecal samples. Among 54 positive samples, 13 were positive in non-diarrheal samples (n = 48, 27.1%) and 41 in diarrheal samples (n = 99, 41.4%). Genetic analyses demonstrated that all the segments of ZP18-18, except for VP4, had high nucleotide sequence identities (80.6-92.6%) with all other known RVB strains detected in pigs. In contrast, the VP4 sequence of ZP18-18 was highly divergent from other RVB strains (< 64.6% identities) and formed a distinct lineage in the phylogenetic tree. Notably, the VP8 subunit of the VP4 showed remarkably low amino acid identities (33.3%) to those of known RVB strains, indicating that the VP8 subunit of ZP18-18 was unique among RVB strains. According to the whole genome classification for RVB, ZP18-18 was assigned to a genotype constellation, G18-P[9]-I12-R4-C4-M4-A8-N10-T5-E4-H7 with the newly established VP4 genotype P[9]. CONCLUSIONS: This current study updates the geographical distribution and the genetic diversity of RVB. Given the lack of information regarding RVB in Africa, further RVB surveillance is required to assess the potential risk to humans and animals.


Assuntos
Proteínas do Capsídeo , Fezes , Genoma Viral , Genótipo , Filogenia , Infecções por Rotavirus , Rotavirus , Doenças dos Suínos , Animais , Suínos , Zâmbia/epidemiologia , Rotavirus/genética , Rotavirus/classificação , Rotavirus/isolamento & purificação , Infecções por Rotavirus/virologia , Infecções por Rotavirus/veterinária , Infecções por Rotavirus/epidemiologia , Fezes/virologia , Doenças dos Suínos/virologia , Doenças dos Suínos/epidemiologia , Proteínas do Capsídeo/genética , Genoma Viral/genética , Diarreia/virologia , Diarreia/veterinária , Diarreia/epidemiologia , Análise de Sequência de DNA , RNA Viral/genética , Metagenômica , Prevalência
4.
BMC Infect Dis ; 24(1): 942, 2024 Sep 09.
Artigo em Inglês | MEDLINE | ID: mdl-39251928

RESUMO

BACKGROUND: Bacillus anthracis is a highly pathogenic bacterium that can cause lethal infection in animals and humans, making it a significant concern as a pathogen and biological agent. Consequently, accurate diagnosis of B. anthracis is critically important for public health. However, the identification of specific marker genes encoded in the B. anthracis chromosome is challenging due to the genetic similarity it shares with B. cereus and B. thuringiensis. METHODS: The complete genomes of B. anthracis, B. cereus, B. thuringiensis, and B. weihenstephanensis were de novo annotated with Prokka, and these annotations were used by Roary to produce the pan-genome. B. anthracis exclusive genes were identified by Perl script, and their specificity was examined by nucleotide BLAST search. A local BLAST alignment was performed to confirm the presence of the identified genes across various B. anthracis strains. Multiplex polymerase chain reactions (PCR) were established based on the identified genes. RESULT: The distribution of genes among 151 whole-genome sequences exhibited three distinct major patterns, depending on the bacterial species and strains. Further comparative analysis between the three groups uncovered thirty chromosome-encoded genes exclusively present in B. anthracis strains. Of these, twenty were found in known lambda prophage regions, and ten were in previously undefined region of the chromosome. We established three distinct multiplex PCRs for the specific detection of B. anthracis by utilizing three of the identified genes, BA1698, BA5354, and BA5361. CONCLUSION: The study identified thirty chromosome-encoded genes specific to B. anthracis, encompassing previously described genes in known lambda prophage regions and nine newly discovered genes from an undefined gene region to the best of our knowledge. Three multiplex PCR assays offer an accurate and reliable alternative method for detecting B. anthracis. Furthermore, these genetic markers have value in anthrax vaccine development, and understanding the pathogenicity of B. anthracis.


Assuntos
Bacillus anthracis , Cromossomos Bacterianos , Genoma Bacteriano , Reação em Cadeia da Polimerase Multiplex , Bacillus anthracis/genética , Bacillus anthracis/isolamento & purificação , Reação em Cadeia da Polimerase Multiplex/métodos , Cromossomos Bacterianos/genética , Marcadores Genéticos , Antraz/microbiologia , Antraz/diagnóstico , Humanos , Sequenciamento Completo do Genoma/métodos
5.
J Gen Virol ; 102(3)2021 03.
Artigo em Inglês | MEDLINE | ID: mdl-33533710

RESUMO

Encephalomyocarditis virus (EMCV) infects a wide range of hosts and can cause encephalitis, myocarditis, reproductive disorders and diabetes mellitus in selected mammalian species. As for humans, EMCV infection seems to occur by the contact with animals and can cause febrile illnesses in some infected patients. Here we isolated EMCV strain ZM12/14 from a natal multimammate mouse (Mastomys natalensis: M. natalensis) in Zambia. Pairwise sequence similarity of the ZM12/14 P1 region consisting of antigenic capsid proteins showed the highest similarity of nucleotide (80.7 %) and amino acid (96.2%) sequence with EMCV serotype 1 (EMCV-1). Phylogenetic analysis revealed that ZM12/14 clustered into EMCV-1 at the P1 and P3 regions but segregated from known EMCV strains at the P2 region, suggesting a unique evolutionary history. Reverse transcription PCR (RT-PCR) screening and neutralizing antibody assays for EMCV were performed using collected tissues and serum from various rodents (n=179) captured in different areas in Zambia. We detected the EMCV genome in 19 M. natalensis (19/179=10.6 %) and neutralizing antibody for EMCV in 33 M. natalensis (33/179=18.4 %). However, we did not detect either the genome or neutralizing antibody in other rodent species. High neutralizing antibody litres (≧320) were observed in both RT-PCR-negative and -positive animals. Inoculation of ZM12/14 caused asymptomatic persistent infection in BALB/c mice with high antibody titres and high viral loads in some organs, consistent with the above epidemiological results. This study is the first report of the isolation of EMCV in Zambia, suggesting that M. natalensis may play a role as a natural reservoir of infection.


Assuntos
Infecções por Cardiovirus/veterinária , Reservatórios de Doenças/virologia , Vírus da Encefalomiocardite/isolamento & purificação , Murinae/virologia , Doenças dos Roedores/virologia , Animais , Anticorpos Neutralizantes/sangue , Anticorpos Antivirais/sangue , Infecções por Cardiovirus/epidemiologia , Infecções por Cardiovirus/virologia , Vírus da Encefalomiocardite/genética , Vírus da Encefalomiocardite/imunologia , Vírus da Encefalomiocardite/patogenicidade , Evolução Molecular , Genoma Viral , Camundongos Endogâmicos BALB C , Filogenia , Prevalência , Doenças dos Roedores/epidemiologia , Musaranhos/virologia , Zâmbia/epidemiologia
6.
J Fish Dis ; 44(6): 721-727, 2021 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-33522610

RESUMO

The pathogenesis of Lactococcus garvieae (L. garvieae) was assessed in Nile tilapia (Oreochromis niloticus) following administration by two different routes of infection (intraperitoneal versus immersion), using 180 fish divided into three groups. The first group of fish was injected intraperitoneally (IP) with 3 × 105 colony-forming units (cfu) of L. garvieae; the second group was infected by immersion (IMM) into water containing 9.6 × 105  cfu/ml L. garvieae, and in group 3 (Control), the fish were injected IP with sterile normal saline. Mortalities were recorded daily, and on 3, 5, 7, and 13 days post-infection (dpi), liver, kidney, spleen, brain and eyes were sampled. The level of infection between groups was assessed by number of mortalities that occurred, pathology/histopathology of internal organs, bacterial re-isolation and presence of bacteria in situ determined using immunohistochemistry. A significant difference (p < .0001) was observed between L. garvieae re-isolation from tilapia following administration by IP injection and IMM. Similarly, more clinical signs and mortalities (p < .001) were observed in the IP group compared to the IMM group where no mortalities were observed. These findings suggest that L. garvieae has a low invasive potential in Nile tilapia with intact skin/external barriers and highlights the importance of maintaining fish without cuts or abrasions under field conditions.


Assuntos
Ciclídeos , Doenças dos Peixes/microbiologia , Infecções por Bactérias Gram-Positivas/veterinária , Lactococcus/fisiologia , Animais , Infecções por Bactérias Gram-Positivas/microbiologia , Lagos , Zâmbia
7.
Emerg Infect Dis ; 26(4): 811-814, 2020 04.
Artigo em Inglês | MEDLINE | ID: mdl-32187004

RESUMO

We detected West Nile virus (WNV) nucleic acid in crocodiles (Crocodylus niloticus) in Zambia. Phylogenetically, the virus belonged to lineage 1a, which is predominant in the Northern Hemisphere. These data provide evidence that WNV is circulating in crocodiles in Africa and increases the risk for animal and human transmission.


Assuntos
Jacarés e Crocodilos , Febre do Nilo Ocidental , Vírus do Nilo Ocidental , Animais , Humanos , Febre do Nilo Ocidental/epidemiologia , Febre do Nilo Ocidental/veterinária , Vírus do Nilo Ocidental/genética , Zâmbia/epidemiologia
8.
J Gen Virol ; 101(10): 1027-1036, 2020 10.
Artigo em Inglês | MEDLINE | ID: mdl-32706330

RESUMO

Mammalian orthoreovirus (MRV) has been identified in humans, livestock and wild animals; this wide host range allows individual MRV to transmit into multiple species. Although several interspecies transmission and genetic reassortment events of MRVs among humans, livestock and wildlife have been reported, the genetic diversity and geographic distribution of MRVs in Africa are poorly understood. In this study, we report the first isolation and characterization of MRVs circulating in a pig population in Zambia. In our screening, MRV genomes were detected in 19.7 % (29/147) of faecal samples collected from pigs by reverse transcription PCR. Three infectious MRV strains (MRV-85, MRV-96 and MRV-117) were successfully isolated, and their complete genomes were sequenced. Recombination analyses based on the complete genome sequences of the isolated MRVs demonstrated that MRV-96 shared the S3 segment with a different MRV isolated from bats, and that the L1 and M3 segments of MRV-117 originated from bat and human MRVs, respectively. Our results suggest that the isolated MRVs emerged through genetic reassortment events with interspecies transmission. Given the lack of information regarding MRVs in Africa, further surveillance of MRVs circulating among humans, domestic animals and wildlife is required to assess potential risk for humans and animals.


Assuntos
Fezes/virologia , Orthoreovirus de Mamíferos/genética , Orthoreovirus de Mamíferos/isolamento & purificação , Infecções por Reoviridae/veterinária , Doenças dos Suínos/virologia , Suínos/virologia , Animais , Animais Selvagens/classificação , Animais Selvagens/virologia , Quirópteros/virologia , Genoma Viral , Especificidade de Hospedeiro , Filogenia , Prevalência , Vírus Reordenados/genética , Recombinação Genética , Infecções por Reoviridae/epidemiologia , Infecções por Reoviridae/virologia , Doenças dos Suínos/epidemiologia , Proteínas Virais/genética , Sequenciamento Completo do Genoma , Zâmbia/epidemiologia
9.
Emerg Infect Dis ; 25(8): 1577-1580, 2019 08.
Artigo em Inglês | MEDLINE | ID: mdl-31146800

RESUMO

We detected Marburg virus genome in Egyptian fruit bats (Rousettus aegyptiacus) captured in Zambia in September 2018. The virus was closely related phylogenetically to the viruses that previously caused Marburg outbreaks in the Democratic Republic of the Congo. This finding demonstrates that Zambia is at risk for Marburg virus disease.


Assuntos
Quirópteros/virologia , Doença do Vírus de Marburg/virologia , Marburgvirus , Animais , Genes Virais , Humanos , Doença do Vírus de Marburg/diagnóstico , Doença do Vírus de Marburg/epidemiologia , Marburgvirus/classificação , Marburgvirus/genética , Marburgvirus/isolamento & purificação , Filogenia , Prevalência , Vigilância em Saúde Pública , RNA Viral , Zâmbia/epidemiologia
10.
Arch Virol ; 164(8): 2165-2170, 2019 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-31154511

RESUMO

Zika virus (ZIKV) circulation occurs between non-human primates (NHPs) in a sylvatic transmission cycle. To investigate evidence of flavivirus infection in NHPs in Zambia, we performed a plaque reduction neutralization test (PRNT) to quantify neutralizing antibodies. PRNT revealed that sera from NHPs (African green monkeys and baboons) exhibited neutralizing activity against ZIKV (34.4%; 33/96), whereas a PRNT for yellow fever virus using NHP sera showed no neutralization activity. ZIKV genomic RNA was not detected in splenic tissues from NHPs, suggesting that the presence of anti-ZIKV neutralizing antibodies represented resolved infections. Our evidence suggests that ZIKV is maintained in NHP reservoirs in Zambia.


Assuntos
Infecção por Zika virus/imunologia , Infecção por Zika virus/virologia , Zika virus/imunologia , Animais , Anticorpos Neutralizantes/imunologia , Anticorpos Antivirais/imunologia , Reações Cruzadas/imunologia , Vírus da Dengue/imunologia , Infecções por Flavivirus/imunologia , Infecções por Flavivirus/virologia , Primatas , Testes Sorológicos/métodos , Zâmbia
11.
BMC Microbiol ; 18(1): 2, 2018 01 04.
Artigo em Inglês | MEDLINE | ID: mdl-29433443

RESUMO

BACKGROUND: Plague is a flea-borne zoonotic and invasive disease caused by a gram negative coccobacillus bacterium called Yersinia pestis. Plague has caused three devastating pandemics globally namely: the Justinian, Black Death and Oriental plague. The disease in the Eastern Province of Zambia has been reported in Nyimba and Sinda Districts in the past 15 years. The aim of this study was to investigate the molecular epidemiology of plague in the two affected districts. Polymerase Chain Reaction (PCR), targeting Plasminogen activator gene (pla gene) of Y. pestis, was performed on suspected human bubo aspirates (n = 7), rodents (n = 216), shrews (n = 27) and fleas (n = 1494). Of these, one positive sample from each source or host was subjected to sequencing followed by phylogenetic analysis. RESULTS: The plasminogen activator gene (pla gene) of Y. pestis was detected in 42.8% bubo aspirates, 6.9% rodents, 3.7% shrew and 0.8% fleas. The fleas were from pigs (n = 4), goats (n = 5) and rodents (n = 3). The sequencing and phylogenetic analysis suggested that the pla gene of Y. pestis in Nyimba and Sinda was similar and the isolates demonstrated a high degree of evolutionary relationship with Antiqua strains from the Republic of Congo and Kenya. CONCLUSION: It can be concluded that pla gene of Y. pestis was present in various hosts in the two districts and the strains circulating in each district were similar and resembles those in the Republic of Congo and Kenya.


Assuntos
Proteínas de Bactérias/genética , Reservatórios de Doenças/microbiologia , Epidemiologia Molecular , Peste/microbiologia , Ativadores de Plasminogênio/genética , Yersinia pestis/genética , Yersinia pestis/isolamento & purificação , Animais , Congo , DNA Bacteriano/genética , Surtos de Doenças , Monitoramento Epidemiológico/veterinária , Evolução Molecular , Cabras , Humanos , Quênia , Filogenia , Peste/epidemiologia , Peste/transmissão , Reação em Cadeia da Polimerase/veterinária , Roedores/microbiologia , Roedores/parasitologia , Análise de Sequência , Musaranhos , Sifonápteros/microbiologia , Suínos , Yersinia pestis/classificação , Zâmbia
12.
Avian Pathol ; 47(3): 300-313, 2018 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-29517272

RESUMO

Infectious bursal disease (IBD) is a highly contagious, immunosuppressive disease of chickens and causes substantial economic losses to the poultry industry globally. This study investigated the genetic characteristics and pathological lesions induced by IBD viruses (IBDVs) that were associated with 60 suspected outbreaks in chickens during 2015-2016 in Lusaka Province, Zambia. Nucleotide sequences of VP2 hypervariable region (VP2-HVR) (n = 38) and part of VP1 (n = 37) of Zambian IBDVs were phylogenetically analysed. Phylogenetic analysis of the VP2-HVR and VP1 revealed that most viruses (n = 31 of each genome segment) clustered with the very virulent (vv) strains. The rest of the viruses clustered with the classical strains, with two of the viruses being closely related to attenuated vaccine isolates. Two of the viruses that belonged to the vv genotype had a unique amino acid (aa) substitution Q324L whereas one virus had two unique changes, N280S and E300A in the VP2-HVR aa sequence. Although Zambian strains with a vv genotype possessed virulence marker aa within VP1 at 145T, 146D and 147N, two viruses showed unique substitutions, with one virus having 147T while the other had 147H. Pathologically, it was noted that only viruses with a vv genotype appeared to be associated with inducing pathological lesions in non-lymphoid organs (proventriculus and gizzard). Whilst documenting for the first time the presence of classical virulent IBDVs, this study demonstrates the involvement of multiple genotypes, with predominance of vvIBDVs in the epidemiology of IBD in Zambia.


Assuntos
Infecções por Birnaviridae/veterinária , Surtos de Doenças/veterinária , Vírus da Doença Infecciosa da Bursa/isolamento & purificação , Doenças das Aves Domésticas/virologia , Sequência de Aminoácidos , Animais , Infecções por Birnaviridae/epidemiologia , Infecções por Birnaviridae/virologia , Galinhas , Genótipo , Técnicas de Genotipagem/veterinária , Vírus da Doença Infecciosa da Bursa/genética , Vírus da Doença Infecciosa da Bursa/patogenicidade , Epidemiologia Molecular , Filogenia , Doenças das Aves Domésticas/epidemiologia , Alinhamento de Sequência/veterinária , Virulência , Zâmbia/epidemiologia
13.
J Gen Virol ; 98(4): 726-738, 2017 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-28430100

RESUMO

Bat species represent natural reservoirs for a number of high-consequence human pathogens. The present study investigated the diversity of polyomaviruses (PyVs) in Zambian insectivorous and fruit bat species. We describe the complete genomes from four newly proposed African bat PyV species employing the recently recommended criteria provided by the Polyomaviridae Study Group of the International Committee on Taxonomy of Viruses. A comprehensive phylogenetic and recombination analysis was performed to determine genetic relationships and the distribution of recombination events in PyV from mammalian and avian species. The novel species of PyV from Zambian bats segregated with members of the genera Alphapolyomavirus and Betapolyomavirus, forming monophyletic clades with bat and non-human primate PyVs. Miniopterus schreibersii polyomavirus 1 and 2 segregated in a clade with South American bat PyV species, Old World monkey and chimpanzee PyVs and Human polyomavirus 13 (New Jersey PyV). Interestingly, the newly described Egyptian fruit bat PyV, tentatively named Rousettus aegyptiacus polyomavirus 1, had the highest nucleotide sequence identity to species of PyV from Indonesian fruit bats, and Rhinolophus hildebrandtii polyomavirus 1 was most closely related to New World monkey PyVs. The distribution of recombination events in PyV genomes was non-random: recombination boundaries existed in the intergene region between VP1 and LTAg and also at the 3' end of VP2/3 in the structural genes, whereas infrequent recombination was present within the LTAg gene. These findings indicate that recombination within the LTAg gene has been negatively selected against during polyomaviral evolution and support the recent proposal for taxonomic classification based on LTAg to define novel PyV species.


Assuntos
Antígenos Virais de Tumores/genética , Quirópteros/virologia , Infecções por Polyomavirus/veterinária , Polyomavirus/classificação , Polyomavirus/isolamento & purificação , Recombinação Genética , Animais , Análise por Conglomerados , Genoma Viral , Filogenia , Polyomavirus/genética , Infecções por Polyomavirus/virologia , Análise de Sequência de DNA , Homologia de Sequência , Zâmbia
14.
J Gen Virol ; 98(11): 2771-2785, 2017 11.
Artigo em Inglês | MEDLINE | ID: mdl-28984241

RESUMO

Polyomaviruses (PyVs) are considered to be highly host-specific in different mammalian species, with no well-supported evidence for host-switching events. We examined the species diversity and host specificity of PyVs in horseshoe bats (Rhinolophus spp.), a broadly distributed and highly speciose mammalian genus. We annotated six PyV genomes, comprising four new PyV species, based on pairwise identity within the large T antigen (LTAg) coding region. Phylogenetic comparisons revealed two instances of highly related PyV species, one in each of the Alphapolyomavirus and Betapolyomavirus genera, present in different horseshoe bat host species (Rhinolophus blasii and R. simulator), suggestive of short-range host-switching events. The two pairs of Rhinolophus PyVs in different horseshoe bat host species were 99.9 and 88.8 % identical with each other over their respective LTAg coding sequences and thus constitute the same virus species. To corroborate the species identification of the bat hosts, we analysed mitochondrial cytb and a large nuclear intron dataset derived from six independent and neutrally evolving loci for bat taxa of interest. Bayesian estimates of the ages of the most recent common ancestors suggested that the near-identical and more distantly related PyV species diverged approximately 9.1E4 (5E3-2.8E5) and 9.9E6 (4E6-18E6) years before the present, respectively, in contrast to the divergence times of the bat host species: 12.4E6 (10.4E6-15.4E6). Our findings provide evidence that short-range host-switching of PyVs is possible in horseshoe bats, suggesting that PyV transmission between closely related mammalian species can occur.


Assuntos
Quirópteros , Variação Genética , Especificidade de Hospedeiro , Infecções por Polyomavirus/veterinária , Polyomavirus/classificação , Polyomavirus/isolamento & purificação , Infecções Tumorais por Vírus/veterinária , África , Animais , Antígenos Virais de Tumores/genética , Evolução Molecular , Filogenia , Polyomavirus/fisiologia , Infecções por Polyomavirus/virologia , Análise de Sequência de DNA , Homologia de Sequência , Infecções Tumorais por Vírus/virologia
15.
Arch Virol ; 162(2): 543-548, 2017 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-27804019

RESUMO

To investigate the diversity of simian immunodeficiency virus (SIV) among nonhuman primates (NHPs) in Zambia, next-generation sequencing was performed to determine the complete genome sequence of a novel SIV recovered by co-culturing African green monkey (AGM) peripheral blood lymphocytes with human CD4+ T-cell lines. We report the first described SIV (SIVagmMAL-ZMB) from a malbrouck (Chlorocebus cynosuros). SIVagmMAL-ZMB was detected by real-time PCR analysis of splenic RNA in 3.2% (3/94) of AGMs and was undetectable in baboons (0/105). SIVagmMAL-ZMB possessed <80% nucleotide sequence identity to known SIV isolates and was located basally to vervet monkey SIV strains in all phylogenies.


Assuntos
Cercopithecinae/virologia , Filogenia , RNA Viral/genética , Síndrome de Imunodeficiência Adquirida dos Símios/epidemiologia , Vírus da Imunodeficiência Símia/classificação , Animais , Linfócitos T CD4-Positivos/virologia , Técnicas de Cocultura , Humanos , Papio , Reação em Cadeia da Polimerase em Tempo Real , Síndrome de Imunodeficiência Adquirida dos Símios/virologia , Vírus da Imunodeficiência Símia/genética , Vírus da Imunodeficiência Símia/isolamento & purificação , Baço/virologia , Zâmbia/epidemiologia
16.
J Gen Virol ; 97(10): 2488-2493, 2016 10.
Artigo em Inglês | MEDLINE | ID: mdl-27574104

RESUMO

Group A rotavirus is a major cause of diarrhoea in humans, especially in young children. Bats also harbour group A rotaviruses, but the genetic backgrounds of bat rotavirus strains are usually distinct from those of human rotavirus strains. We identified a new strain of group A rotavirus in the intestinal contents of a horseshoe bat in Zambia. Whole genome sequencing revealed that the identified virus, named RVA/Bat-wt/ZMB/LUS12-14/2012/G3P[3], possessed the genotype constellation G3-P[3]-I3-R2-C2-M3-A9-N2-T3-E2-H3. Several genome segments of LUS12-14 were highly similar to those of group A rotaviruses identified from humans, cows and antelopes, indicating interspecies transmission of rotaviruses between bats and other mammals with possible multiple genomic reassortment events.


Assuntos
Quirópteros/virologia , Vírus Reordenados/isolamento & purificação , Infecções por Rotavirus/veterinária , Infecções por Rotavirus/virologia , Rotavirus/isolamento & purificação , Animais , Genoma Viral , Genótipo , Humanos , Filogenia , Vírus Reordenados/classificação , Vírus Reordenados/genética , Vírus Reordenados/fisiologia , Rotavirus/classificação , Rotavirus/genética , Rotavirus/fisiologia , Proteínas Virais/genética , Zâmbia
17.
Arch Virol ; 161(3): 513-9, 2016 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-26597187

RESUMO

Infectious bursal disease (IBD) is an acute, highly contagious, and immunosuppressive viral disease of young chickens and remains one of the economically most important diseases threatening the poultry industry worldwide. In this study, 16 and 11 nucleotide sequences of the VP2 hypervariable region (VP2-HVR) and part of VP1, respectively, of IBD virus (IBDV) detected in vaccinated broiler chickens in Lusaka in 2012 were determined. Phylogenetic analysis revealed that these Zambian IBDVs separated into three genotypes of very virulent (VV) IBDVs. Although the majority of these viruses belonged to the African VV type (VV1), which consisted of viruses from West Africa, South Africa and Zambia, one virus belonged to the East African VV type (VV2). Interestingly, a Zambian IBDV belonging to the VV3 genotype (composed of viruses from several continents) clustered with attenuated vaccine strains. Although sequence analysis of VP2-HVR showed that all detected Zambian IBDVs had conserved putative virulence marker amino acids (i.e., 222A, 242I, 256I, 294I and 299S), one virus had two unique amino acid substitutions, N280S and E300A. This study demonstrates the diversity of Zambian IBDVs and documents for the first time the possible involvement of attenuated vaccine strains in the epidemiology of IBD in Zambia. Strict biosecurity of poultry farms, monitoring of live vaccine use in the field, surveillance and characterization of IBDV in poultry and development of a vaccine from local or regional IBDV field strains are recommended for improved IBD control in Zambia.


Assuntos
Infecções por Birnaviridae/veterinária , Vírus da Doença Infecciosa da Bursa/classificação , Vírus da Doença Infecciosa da Bursa/isolamento & purificação , Doenças das Aves Domésticas/virologia , Animais , Infecções por Birnaviridae/virologia , Galinhas , Análise por Conglomerados , Genótipo , Vírus da Doença Infecciosa da Bursa/genética , Dados de Sequência Molecular , Filogenia , RNA Viral/genética , Análise de Sequência de DNA , Homologia de Sequência , Proteínas Estruturais Virais/genética , Zâmbia
18.
Emerg Infect Dis ; 21(7): 1230-3, 2015 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-26079728

RESUMO

Viral metagenomic analysis identified a new parvovirus genome in the intestinal contents of wild shrews in Zambia. Related viruses were detected in spleen tissues from wild shrews and nonhuman primates. Phylogenetic analyses showed that these viruses are related to human bufaviruses, highlighting the presence and genetic diversity of bufaviruses in wildlife.


Assuntos
Papio cynocephalus/virologia , Papio ursinus/virologia , Infecções por Parvoviridae/veterinária , Parvovirus/genética , Musaranhos/virologia , Animais , Infecções por Parvoviridae/virologia , Parvovirus/isolamento & purificação , Análise de Sequência de DNA
19.
J Gen Virol ; 96(Pt 2): 390-394, 2015 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-25319753

RESUMO

Human monkeypox is a viral zoonosis caused by monkeypox virus, an orthopoxvirus (OPXV). The majority of human monkeypox cases have been reported in moist forested regions in West and Central Africa, particularly in the Democratic Republic of the Congo (DRC). In this study we investigated zoonotic OPXV infection among wild animals in Zambia, which shares a border with DRC, to assess the geographical distribution of OPXV. We screened for OPXV antibodies in sera from non-human primates (NHPs), rodents and shrews by ELISA, and performed real-time PCR to detect OPXV DNA in spleen samples. Serological analysis indicated that 38 of 259 (14.7 %) rodents, 14 of 42 (33.3 %) shrews and 4 of 188 (2.1 %) NHPs had antibodies against OPXV. The OPXV DNA could not be detected in spleens from any animals tested. Our results indicated that wild animals living in rural human habitation areas of Zambia have been infected with OPXV.


Assuntos
Anticorpos Antivirais/sangue , DNA Viral/isolamento & purificação , Orthopoxvirus/isolamento & purificação , Infecções por Poxviridae/veterinária , Zoonoses/epidemiologia , Animais , Animais Selvagens , DNA Viral/genética , Ensaio de Imunoadsorção Enzimática , Orthopoxvirus/genética , Orthopoxvirus/imunologia , Reação em Cadeia da Polimerase , Infecções por Poxviridae/epidemiologia , Infecções por Poxviridae/virologia , Primatas , Roedores , Estudos Soroepidemiológicos , Musaranhos , Baço/virologia , Topografia Médica , Zâmbia/epidemiologia , Zoonoses/virologia
20.
J Gen Virol ; 96(Pt 2): 440-452, 2015 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-25381053

RESUMO

Shrews are small insectivorous mammals that are distributed worldwide. Similar to rodents, shrews live on the ground and are commonly found near human residences. In this study, we investigated the enteric virome of wild shrews in the genus Crocidura using a sequence-independent viral metagenomics approach. A large portion of the shrew enteric virome was composed of insect viruses, whilst novel viruses including cyclovirus, picornavirus and picorna-like virus were also identified. Several cycloviruses, including variants of human cycloviruses detected in cerebrospinal fluid and stools, were detected in wild shrews at a high prevalence rate. The identified picornavirus was distantly related to human parechovirus, inferring the presence of a new genus in this family. The identified picorna-like viruses were characterized as different species of calhevirus 1, which was discovered previously in human stools. Complete or nearly complete genome sequences of these novel viruses were determined in this study and then were subjected to further genetic characterization. Our study provides an initial view of the diversity and distinctiveness of the shrew enteric virome and highlights unique novel viruses related to human stool-associated viruses.


Assuntos
Biota , Intestinos/virologia , Metagenoma , Musaranhos/virologia , Vírus/classificação , Vírus/genética , Animais , Análise por Conglomerados , Dados de Sequência Molecular , Filogenia , Análise de Sequência de DNA
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