RESUMO
Members of the Picornaviridae family comprise a significant burden on the poultry industry, causing diseases such as gastroenteritis and hepatitis. However, with the advent of metagenomics, a number of picornaviruses have now been revealed in apparently healthy wild birds. In this study, we identified four novel viruses belonging to the family Picornaviridae in healthy Magellanic penguins, a near threatened species. All samples were subsequently screened by RT-PCR for these new viruses, and approximately 20% of the penguins were infected with at least one of these viruses. The viruses were distantly related to members of the genera Hepatovirus, Tremovirus, Gruhelivirus and Crahelvirus. Further, they had more than 60% amino acid divergence from other picornaviruses, and therefore likely constitute novel genera. Our results demonstrate the vast undersampling of wild birds for viruses, and we expect the discovery of numerous avian viruses that are related to hepatoviruses and tremoviruses in the future.
Assuntos
Infecções por Picornaviridae/epidemiologia , Infecções por Picornaviridae/veterinária , Picornaviridae/classificação , Picornaviridae/isolamento & purificação , Spheniscidae/virologia , Animais , Chile/epidemiologia , Espécies em Perigo de Extinção , Filogenia , Picornaviridae/genéticaRESUMO
Coxsackievirus A24 variant (CVA24v), the main causative agent of acute hemorrhagic conjunctivitis (AHC), can be isolated from both the eyes and lower alimentary tract. However, the molecular features of CVA24v in feces is not well-documented. In this study, we compared the VP1 and 3C sequences of CVA24v strains isolated from feces during AHC epidemics in Cuba in 1997, 2003, and 2008-2009 with those obtained from conjunctival swabs during the same epidemic period. The sequence analyses of the 3C and VP1 region of stool isolates from the three epidemics showed a high degree of nucleotide identity (ranging from 97.3-100%) to the corresponding conjunctival isolates. The phylogenetic analysis showed that fecal CVA24v isolates from the 1997 and 2003 Cuban outbreaks formed a clade with CVA24v strains isolated from conjunctival swabs in Cuba and other countries during the same period. There were three amino acid changes (3C region) and one amino acid change (VP1 region) in seven CVA24v strains isolated sequentially over 20 days from fecal samples of one patient, suggesting viral replication in the intestine. Despite these substitutions, the virus from the conjunctival swab and fecal samples were genetically very similar. Therefore, fecal samples should be considered as a reliable alternative sample type for the routine molecular diagnosis and molecular epidemiology of CVA24v, also during outbreaks of AHC.
RESUMO
Coxsackievirus A24 variant (CVA24v) is a major causative agent of acute hemorrhagic conjunctivitis outbreaks worldwide, yet the evolutionary and transmission dynamics of the virus remain unclear. To address this, we analyzed and compared the 3C and partial VP1 gene regions of CVA24v isolates obtained from five outbreaks in Cuba between 1986 and 2009 and strains isolated worldwide. Here we show that Cuban strains were homologous to those isolated in Africa, the Americas and Asia during the same time period. Two genotypes of CVA24v (GIII and GIV) were repeatedly introduced into Cuba and they arose about two years before the epidemic was detected. The two genotypes co-evolved with a population size that is stable over time. However, nucleotide substitution rates peaked during pandemics with 4.39 × 10-3 and 5.80 × 10-3 substitutions per site per year for the 3C and VP1 region, respectively. The phylogeographic analysis identified 25 and 19 viral transmission routes based on 3C and VP1 regions, respectively. Pandemic viruses usually originated in Asia, and both China and Brazil were the major hub for the global dispersal of the virus. Together, these data provide novel insight into the epidemiological dynamics of this virus and possibly other pandemic viruses.
Assuntos
Proteínas do Capsídeo/genética , Conjuntivite Hemorrágica Aguda/epidemiologia , Infecções por Coxsackievirus/epidemiologia , Cisteína Endopeptidases/genética , Enterovirus Humano C/genética , Proteínas Virais/genética , Proteases Virais 3C , Sequência de Bases , Conjuntivite Hemorrágica Aguda/patologia , Conjuntivite Hemorrágica Aguda/transmissão , Infecções por Coxsackievirus/patologia , Infecções por Coxsackievirus/transmissão , Cuba/epidemiologia , Surtos de Doenças , Evolução Molecular , Humanos , Filogenia , Alinhamento de SequênciaRESUMO
Hepatitis B virus (HBV) and hepatitis C virus (HCV) infections are the principal risk factor associated to end-stage liver diseases in the world. A study was carried out on end-stage liver disease cases admitted to an important hepatology unit in Medellin, the second largest city in Colombia. From 131 patients recruited in this prospective study, 71% of cases were diagnosed as cirrhosis, 12.2% as HCC, and 16.8% as cirrhosis and HCC. Regarding the risk factors of these patients, alcohol consumption was the most frequent (37.4%), followed by viral etiology (17.6%). Blood and/or hepatic tissue samples from patients with serological markers for HCV or HBV infection were characterized; on the basis of the phylogenetic analysis of HCV 5' UTR and HBV S gene, isolates belonged to HCV/1 and HBV/F3, respectively. These results confirm the presence of strains associated with poor clinical outcome, in patients with liver disease in Colombia; additionally, HBV basal core promoter double mutant was identified in HCC cases. Here we show the first study of cirrhosis and/or HCC in Colombian and HBV and HCV molecular characterization of these patients. Viral aetiology was not the main risk factor in this cohort but alcohol consumption.
RESUMO
Coxsackievirus A24 variant is, together with enterovirus 70 and adenoviruses, the major etiological agent involved in acute hemorrhagic conjunctivitis outbreaks worldwide. However, the standard virus isolation method followed by serotyping or VP1 region sequencing is time-consuming. A rapid method for the detection of coxsackievirus A24 variant from conjunctival swab specimens would be useful in the context of explosive and extensive outbreaks. A one-step real-time RT-PCR assay based on TaqMan technology was thus developed and assessed on 36 conjunctival swabs from outbreaks of conjunctivitis in Morocco in 2004 due to a coxsackievirus A24 variant and in Corsica in 2006 due to adenovirus type 3, and 83 virus strains including 41 coxsackievirus A24 variant collected in French Guiana and Guadeloupe in 2003, in the Democratic Republic of the Congo in 2003, in Morocco in 2004 and 42 other virus species genetically close or known to be responsible for conjunctivitis. All the conjunctival swabs from coxsackievirus A24 variant related outbreak and the 41 coxsackievirus A24 variant strains were tested positive by the RT-PCR assay within 4h. This novel single-tube real-time RT-PCR assay is sensitive and specific, and consists in a reliable and faster alternative to the viral culture for recent and future acute hemorrhagic conjunctivitis outbreaks caused by coxsackievirus A24 variant.
Assuntos
Conjuntivite Hemorrágica Aguda/diagnóstico , Conjuntivite Hemorrágica Aguda/epidemiologia , Surtos de Doenças , Enterovirus Humano C/isolamento & purificação , Reação em Cadeia da Polimerase Via Transcriptase Reversa/métodos , Túnica Conjuntiva/virologia , Conjuntivite Hemorrágica Aguda/virologia , República Democrática do Congo/epidemiologia , Enterovirus Humano C/classificação , Enterovirus Humano C/genética , Guiana Francesa/epidemiologia , Guadalupe/epidemiologia , Humanos , Dados de Sequência Molecular , Marrocos/epidemiologia , Sensibilidade e Especificidade , Análise de Sequência de DNA , Fatores de TempoRESUMO
An outbreak of acute hemorrhagic conjunctivitis occurred in French Guiana between April and July 2003, with approximately 6,000 cases in the two major cities Kourou and Cayenne. Since acute hemorrhagic conjunctivitis is not a notifiable disease in France, there was no registration of the number of cases. Therefore, these were estimated by comparing the consumption of antibiotic eye drops and ophthalmic ointments during 2002 and 2003. The outbreak rapidly spread into the Caribbean Islands, causing an outbreak in Guadeloupe in October. Viral isolates from conjunctival swabs of 16 patients were confirmed to be enterovirus by PCR directed to the 5' UTR of the genome. The isolates could not be neutralized by the Melnick intersecting pools, but were shown to be CV-A24 variant by limited sequencing within the VP1 and 3C regions of 12 strains. Phylogenetic analysis revealed that they were similar to the genotype III strains causing outbreaks in Korea 2002 and Malaysia 2003. The previous outbreak of conjunctivitis caused by CV-A24 in the Caribbean in the 1980s was also introduced from Asia, and disappeared after 3 years. This new introduction from Asia and its rapid spread into the Caribbean, where the infection disappeared after a few months, indicates that the CV-A24 variant has a different epidemiological pattern in this region compared to South East Asia, since it has not established an endemic infection. It had to be reintroduced from Asia, where it has been circulating since the 1970s.
Assuntos
Doenças Transmissíveis Emergentes/epidemiologia , Conjuntivite Hemorrágica Aguda/epidemiologia , Surtos de Doenças , Enterovirus Humano C/isolamento & purificação , Filogenia , Adulto , Ásia/epidemiologia , Criança , Doenças Transmissíveis Emergentes/virologia , Conjuntivite Hemorrágica Aguda/virologia , Infecções por Coxsackievirus/epidemiologia , Infecções por Coxsackievirus/virologia , Enterovirus Humano C/classificação , Enterovirus Humano C/genética , Feminino , Guiana Francesa/epidemiologia , Humanos , Masculino , Pessoa de Meia-Idade , Dados de Sequência Molecular , Análise de Sequência de DNA , Índias Ocidentais/epidemiologiaRESUMO
The precore mutation G(1896)-->A occurs frequently in anti-HBe-positive carriers of HBsAg with T(1858) in the stem of the encapsidation signal. Hepatitis B virus (HBV) genotype F, considered an Amerindian genotype, subdivides into two clades and the precore mutation occurs in Central American F strains. To investigate the relationship between substitutions at position 1858 and these clades, the precore and small S genes of 48 strains of HBV genotype F were subjected to phylogenetic analyses. Isolates of one clade, formed mainly of Central American strains, all had T(1858) and Thr(45) in the S gene, whereas in the other clade, formed mainly of South American strains and one strain from Polynesia, all had C(1858) and Leu(45). The latter strain was related to strains from Venezuela and Colombia, supporting an Amerindian contribution to the Polynesian population. The position of the Polynesian strain in the phylogenetic tree indicates that the two clades have resulted from an early split, showing a high degree of genetic stability of the stem of the HBsAg encapsidation signal.
Assuntos
Variação Genética , Antígenos do Núcleo do Vírus da Hepatite B/genética , Vírus da Hepatite B/classificação , Vírus da Hepatite B/genética , Mutação , Precursores de Proteínas/genética , América Central , Genótipo , Antígenos do Núcleo do Vírus da Hepatite B/metabolismo , Antígenos de Superfície da Hepatite B/genética , Humanos , Dados de Sequência Molecular , Filogenia , Polinésia , Precursores de Proteínas/metabolismo , Análise de Sequência de DNA , América do SulRESUMO
The complete genomes were sequenced for ten hepatitis B virus (HBV) strains. Two of them, from Spain and Sweden, were most similar to genotype D, although encoding d specificity. Five of them were from Central America and belonged to genotype F. Two strains from Nicaragua and one from Los Angeles, USA, showed divergences of 3.1-4.1% within the small S gene from genotype F strains and were recognized previously as a divergent clade within genotype F. The complete genomes of the two genotype D strains were found to differ from published genotype D strains by 2.8-4.6%. Their S genes encoded Lys(122), Thr(127) and Lys(160), corresponding to the putative new subtype adw3 within this genotype, previously known to specify ayw2, ayw3 or, rarely, ayw4. The complete genomes of the three divergent strains diverged by 0.8-2.5% from each other, 7.2-10.2% from genotype F strains and 13.2-15.7% from other HBV strains. Since pairwise comparisons of 82 complete HBV genomes of intratypic and intertypic divergences ranged from 0.1 to 7.4% and 6.8 to 17.1%, respectively, the three sequenced strains should represent a new HBV genotype, for which the designation H is proposed. In the polymerase region, the three strains had 16 unique conserved amino acid residues not present in genotype F strains. So far, genotype H has been encountered in Nicaragua, Mexico and California. Phylogenetic analysis of the complete genomes and subgenomes of the three strains showed them clustering with genotype F but forming a separate branch supported by 100% bootstrap. Being most similar to genotype F, known to be an Amerindian genotype, genotype H has most likely split off from genotype F within the New World.