RESUMEN

The ISAV has a genome composed of eight segments of (-)ssRNA, segment 6 codes for the hemagglutinin-esterase protein, and has the most variable region of the genome, the highly polymorphic region (HPR), which is unique among orthomyxoviruses. The HPR has been associated with virulence, infectivity and pathogenicity. The full length of the HPR is called HPR0 and the strain with this HPR is avirulent, in contrast to strains with deleted HPR that are virulent to varying degrees. The molecular mechanism that gives rise to the different HPRs remains unclear. Here, we studied in vitro the evolution of reassortant recombinant ISAV (rISAV) in Atlantic salmon head kidney (ASK) cells. To this end, we rescued and cultivated a set of rISAV with different segment 6-HPR genotypes using a reverse genetics system and then sequencing HPR regions of the viruses. Our results show rapid multiple recombination events in ISAV, with sequence insertions and deletions in the HPR, indicating a dynamic process. Inserted sequences can be found in four segments of the ISAV genome (segments 1, 5, 6, and 8). The results suggest intra-segmental heterologous recombination, probably by class I and class II template switching, similar to the proposed segment 5 recombination mechanism.

Asunto(s)

Isavirus/genética , Isavirus/patogenicidad , Recombinación Genética , Animales , Línea Celular , Enfermedades de los Peces/virología , Genotipo , Hemaglutininas Virales/genética , Infecciones por Orthomyxoviridae/virología , Salmo salar , Análisis de Secuencia de ADN , Proteínas Virales de Fusión/genética , Virulencia/genética

RESUMEN

Canine Distemper Virus (CDV) is a highly contagious pathogen of dogs that causes severe respiratory, gastrointestinal and nervous signs. Although vaccines have been used to prevent infections, CDV has been reported worldwide, even in vaccinated animals. In the present study, a representative wild type CDV strain (Arg24) was isolated from a sick vaccinated dog and its genome was completely sequenced using Illumina technology. This strain produced a strong cytopathic effect in Vero SLAM (Signaling Lymphocyte Activation Molecule) cells with a higher titer of 1.1 × 105 Median Tissue Culture Infectious Dose (TCID50/mL) at 32 h post infection, in cell-associated virus. The Arg24 strain genome, showed values of 97.1, 90.3, 96.7, 90.6, 89.8 and 97.3 % of amino acid identity with respect to the Onderstepoort vaccine strain (Nucleoprotein, Phosphoprotein, Matrix, Fusion, Hemagglutinin and Large polymerase, respectively). Focusing on the Hemagglutinin gene, which is the target for genetic characterization, Arg24 showed four additional potential glycosylation sites, with respect to the Onderstepoort. The availability of Arg24 strain, which can be easily grown in Vero SLAM cells, is an important tool to perform immunological and antigenic comparative studies, between wild type and vaccine CDV strains.

Asunto(s)

Virus del Moquillo Canino/genética , Virus del Moquillo Canino/aislamiento & purificación , Moquillo/virología , ARN Viral/genética , Animales , Chlorocebus aethiops , Perros , Genoma Viral , Hemaglutininas Virales/genética , Masculino , Filogenia , Células Vero , Secuenciación Completa del Genoma

RESUMEN

Canine distemper virus (CDV) is the cause of a multisystem disease in domestic dogs and wild animals, infecting more than 20 carnivore and non-carnivore families and even infecting human cell lines in in vitro conditions. Phylogenetic classification based on the hemagglutinin gene shows 17 lineages with a phylogeographic distribution pattern. In Medellín (Colombia), the lineage South America-3 is considered endemic. Phylogenetic studies conducted in Ecuador using fragment coding for the fusion protein signal peptide (Fsp) characterized a new strain belonging to a different lineage. For understanding the distribution of the South America-3 lineage in the north of the South American continent, we characterized CDV from three Colombian cities (Medellín, Bucaramanga, and Bogotá). Using phylogenetic analysis of the hemagglutinin gene and the Fsp region, we confirmed the circulation of CDV South America-3 in different areas of Colombia. We also described, for the first time to our knowledge, the circulation of a new lineage in Medellín that presents a group monophyletic with strains previously characterized in dogs in Ecuador and in wildlife and domestic dogs in the United States, for which we propose the name "South America/North America-4" due its intercontinental distribution. In conclusion, our results indicated that there are at least four different CDV lineages circulating in domestic dogs in South America: the Europe/South America-1 lineage circulating in Brazil, Uruguay, and Argentina; the South America-2 lineage restricted to Argentina; the South America-3 lineage, which has only been reported in Colombia; and lastly an intercontinental lineage present in Colombia, Ecuador, and the United States, referred to here as the "South America/North America-4" lineage.

Asunto(s)

Virus del Moquillo Canino/genética , Ligamiento Genético , Animales , Teorema de Bayes , Virus del Moquillo Canino/clasificación , Perros , Femenino , Glicopéptidos/clasificación , Glicopéptidos/genética , Hemaglutininas Virales/clasificación , Hemaglutininas Virales/genética , Masculino , América del Norte , Filogenia , Filogeografía , ARN Viral/química , ARN Viral/metabolismo , Análisis de Secuencia de ARN , América del Sur

RESUMEN

Pandemic H1N1, human-like H1N2 and H3N2 influenza A (IAV) viruses are co-circulating in swine herds in Brazil. The genetic analysis of the Brazilian IAVs has shown that they are genetically distinct from viruses found in swine in other countries; therefore, an update of the diagnostic assays for IAV detection and subtyping is needed. This study describes the development and validation of a TaqMan based - one-step multiplex RT-qPCR to discriminate the hemagglutinin and neuraminidase genes of the three major IAV subtypes circulating in pigs in Brazil. The RT-qPCR assays presented 100% (95.7-100, CI 95%) of diagnostic sensitivity in the analysis of 85 IAVs, previously characterized by sequencing. The limits of detection ranged from 5.09 × 101 to 5.09 × 103 viral RNA copies/µL. For the analytical specificity, 73 pig samples collected during 2017 and 2018 were analyzed, resulting in the identification of the subtype in 74.0% (62.9-82.7, CI 95%) of samples. From these, 46.3% were H3N2, 33.3% were H1N1, 11.1% were H1N2 and 3.7% were HxN1. Mixed viral infections (3.7%) and reassortant viruses (1.9%) were also detected by the test. This multiplex RT-qPCR assay provides a fast and specific diagnostic tool for identification of different subtypes and lineages of IAV in pigs, contributing to the monitoring of influenza in swine.

Asunto(s)

Virus de la Influenza A/clasificación , Virus de la Influenza A/aislamiento & purificación , Reacción en Cadena de la Polimerasa Multiplex/métodos , Reacción en Cadena de la Polimerasa Multiplex/veterinaria , Infecciones por Orthomyxoviridae/veterinaria , Enfermedades de los Porcinos/virología , Animales , Brasil , Hemaglutininas Virales/genética , Subtipo H1N1 del Virus de la Influenza A/aislamiento & purificación , Subtipo H3N2 del Virus de la Influenza A/aislamiento & purificación , Límite de Detección , Neuraminidasa/genética , Infecciones por Orthomyxoviridae/diagnóstico , Infecciones por Orthomyxoviridae/virología , ARN Viral/genética , Sensibilidad y Especificidad , Porcinos , Enfermedades de los Porcinos/diagnóstico

RESUMEN

BACKGROUND: Canine distemper virus (CDV), currently termed Canine morbillivirus, is an extremely contagious disease that affects dogs. It is identified as a multiple cell tropism pathogen, and its host range includes a vast array of species. As a member of Mononegavirales, CDV has a negative, single-stranded RNA genome, which encodes eight proteins. MAIN BODY: Regarding the molecular pathogenesis, the hemagglutinin protein (H) plays a crucial role both in the antigenic recognition and the viral interaction with SLAM and nectin-4, the host cells' receptors. These cellular receptors have been studied widely as CDV receptors in vitro in different cellular models. The SLAM receptor is located in lymphoid cells; therefore, the infection of these cells by CDV leads to immunosuppression, the severity of which can lead to variability in the clinical disease with the potential of secondary bacterial infection, up to and including the development of neurological signs in its later stage. CONCLUSION: Improving the understanding of the CDV molecules implicated in the determination of infection, especially the H protein, can help to enhance the biochemical comprehension of the difference between a wide range of CDV variants, their tropism, and different steps in viral infection. The regions of interaction between the viral proteins and the identified host cell receptors have been elucidated to facilitate this understanding. Hence, this review describes the significant molecular and cellular characteristics of CDV that contribute to viral pathogenesis.

Asunto(s)

Virus del Moquillo Canino/genética , Virus del Moquillo Canino/patogenicidad , Moquillo/virología , Interacciones Microbiota-Huesped , Tropismo Viral , Animales , Modelos Animales de Enfermedad , Virus del Moquillo Canino/fisiología , Perros , Hemaglutininas Virales/genética , Especificidad del Huésped , Humanos , Ratones , Nectinas/genética , Receptores Virales/genética , Miembro 1 de la Familia de Moléculas Señalizadoras de la Activación Linfocitaria/genética , Proteínas Virales/genética , Zoonosis/virología

RESUMEN

Wild aquatic birds are the major reservoir of influenza A virus. Cloacal swabs and feces samples (n = 6595) were collected from 62 bird species in Argentina from 2006 to 2016 and screened for influenza A virus. Full genome sequencing of 15 influenza isolates from 6 waterfowl species revealed subtypes combinations that were previously described in South America (H1N1, H4N2, H4N6 (n = 3), H5N3, H6N2 (n = 4), and H10N7 (n = 2)), and new ones not previously identified in the region (H4N8, H7N7 and H7N9). Notably, the internal gene segments of all 15 Argentine isolates belonged to the South American lineage, showing a divergent evolution of these viruses in the Southern Hemisphere. Time-scaled phylogenies indicated that South American gene segments diverged between ~ 30 and ~ 140 years ago from the most closely related influenza lineages, which include the avian North American (PB1, HA, NA, MP, and NS-B) and Eurasian lineage (PB2), and the equine H3N8 lineage (PA, NP, and NS-A). Phylogenetic analyses of the hemagglutinin and neuraminidase gene segments of the H4, H6, and N8 subtypes revealed recent introductions and reassortment between viruses from the Northern and Southern Hemispheres in the Americas. Remarkably and despite evidence of recent hemagglutinin and neuraminidase subtype introductions, the phylogenetic composition of internal gene constellation of these influenza A viruses has remained unchanged. Considering the extended time and the number of sampled species of the current study, and the paucity of previously available data, our results contribute to a better understanding of the ecology and evolution of influenza virus in South America.

Asunto(s)

Animales Salvajes/virología , Aves/virología , Reservorios de Enfermedades/veterinaria , Genes Virales , Genoma Viral , Virus de la Influenza A/genética , Animales , Argentina/epidemiología , Cloaca/virología , Reservorios de Enfermedades/virología , Evolución Molecular , Heces/virología , Hemaglutininas Virales/genética , Subtipo H1N1 del Virus de la Influenza A/genética , Subtipo H1N1 del Virus de la Influenza A/aislamiento & purificación , Subtipo H7N9 del Virus de la Influenza A/genética , Subtipo H7N9 del Virus de la Influenza A/aislamiento & purificación , Virus de la Influenza A/aislamiento & purificación , Gripe Aviar/epidemiología , Gripe Aviar/virología , Neuraminidasa/genética , Filogenia , Reacción en Cadena en Tiempo Real de la Polimerasa , Virus Reordenados

RESUMEN

Canine distemper virus (CDV) is a highly contagious disease pathogen which causes disease in the domestic dog and species classified in the Canidae, Procyonidae, Mustelidae, Hyaenidae, Ursidae, Viveridae, Felidae, Tayassuidae, and Cercopithecidae families. A combined strategy that involved the direct sequencing of amplicons from genes coding for nucleocapsid, large polymerase, and hemagglutinin proteins of CDV, as well as the pathological findings and the immunohistochemical detection of viral nucleocapsid protein in diverse tissues, confirmed the participation of CDV in the development of a neurological disease in a southern tamandua (Tamandua tetradactyla) from Midwestern Brazil. Phylogenetic analysis based on the hemagglutinin gene sequences revealed that the strain from this study grouped with isolates from the Europe 1/South America 1 lineage. The specific polymorphisms at the SLAM receptor-binding site of the hemagglutinin gene, previously linked to disease emergence in novel hosts, were not detected in this genome. These findings represent the first description of CDV-induced infection in the Tamandua tetradactyla and extend the distribution of this infection to include members of the family Myrmecophagidae, order Pilosa.

Asunto(s)

Virus del Moquillo Canino/genética , Moquillo/virología , Hemaglutininas Virales/genética , Xenarthra/virología , Animales , Brasil/epidemiología , Canidae/virología , Moquillo/epidemiología , Virus del Moquillo Canino/clasificación , Virus del Moquillo Canino/fisiología , Perros/virología , Europa (Continente)/epidemiología , Genoma Viral , Inmunohistoquímica , Nucleocápside/genética , Filogenia

RESUMEN

Vaccinia virus (VACV) is the etiological agent of bovine vaccinia (BV), an emerging zoonosis that has been associated with economic losses and social effects. Despite increasing reports of BV outbreaks in Brazil, little is known about the biological interactions of Brazilian VACV (VACV-BR) isolates during coinfections; furthermore, there are no tools for the diagnosis of these coinfections. In this study, a tool to co-detect two variants of VACV was developed to provide new information regarding the pathogenesis, virulence profile, and viral spread during coinfection with VACV-BR isolates. To test the quantitative polymerase chain reactions (qPCR) tool, groups of BALB/c mice were intranasally monoinfected with Pelotas virus 1-Group II (PV1-GII) and Pelotas virus 2-Group I (PV2-GI), or were coinfected with PV1-GII and PV2-GI. Clinical signs of the mice were evaluated and the viral load in lung and spleen were detected using simultaneous polymerase chain reactions (PCR) targeting the A56R (hemagglutinin) gene of VACV. The results showed that qPCR for the quantification of viral load in coinfection was efficient and highly sensitive. Coinfected mice presented more severe disease and a higher frequency of VACV detection in lung and spleen, when compared to monoinfected groups. This study is the first description of PV1 and PV2 pathogenicity during coinfection in mice, and provides a new method to detect VACV-BR coinfections.

Asunto(s)

Enfermedades de los Bovinos/diagnóstico , Coinfección/veterinaria , Reacción en Cadena de la Polimerasa , Virus Vaccinia/fisiología , Vaccinia/veterinaria , Animales , Brasil , Bovinos , Enfermedades de los Bovinos/virología , Coinfección/diagnóstico , Coinfección/virología , Hemaglutininas Virales/genética , Masculino , Ratones , Ratones Endogámicos BALB C , Vaccinia/diagnóstico , Vaccinia/virología , Virus Vaccinia/clasificación , Virus Vaccinia/genética , Virus Vaccinia/patogenicidad , Carga Viral , Virulencia

RESUMEN

Canine distemper virus (CDV) is a highly contagious pathogen for domestic dogs and several wild carnivore species. In Brazil, natural infection of CDV in dogs is very high due to the large non-vaccinated dog population, a scenario that calls for new studies on the molecular epidemiology. This study investigates the phylodynamics and amino-acid signatures of CDV epidemic in South America by analyzing a large dataset compiled from publicly available sequences and also by collecting new samples from Brazil. A population of 175 dogs with canine distemper (CD) signs was sampled, from which 89 were positive for CDV, generating 42 new CDV sequences. Phylogenetic analysis of the new and publicly available sequences revealed that Brazilian sequences mainly clustered in South America 1 (SA1) clade, which has its origin estimated to the late 1980's. The reconstruction of the demographic history in SA1 clade showed an epidemic expanding until the recent years, doubling in size every nine years. SA1 clade epidemic distinguished from the world CDV epidemic by the emergence of the R580Q strain, a very rare and potentially detrimental substitution in the viral genome. The R580Q substitution was estimated to have happened in one single evolutionary step in the epidemic history in SA1 clade, emerging shortly after introduction to the continent. Moreover, a high prevalence (11.9%) of the Y549H mutation was observed among the domestic dogs sampled here. This finding was associated (p<0.05) with outcome-death and higher frequency in mixed-breed dogs, the later being an indicator of a continuous exchange of CDV strains circulating among wild carnivores and domestic dogs. The results reported here highlight the diversity of the worldwide CDV epidemic and reveal local features that can be valuable for combating the disease.

Asunto(s)

Virus del Moquillo Canino/genética , Moquillo/epidemiología , Epidemias , Hemaglutininas Virales/genética , Filogenia , ARN Viral/genética , Sustitución de Aminoácidos , Animales , Teorema de Bayes , Brasil/epidemiología , Moquillo/transmisión , Moquillo/virología , Virus del Moquillo Canino/clasificación , Virus del Moquillo Canino/aislamiento & purificación , Perros , Femenino , Masculino , Epidemiología Molecular , Mutación

RESUMEN

Canine distemper virus (CDV) is a highly contagious viral disease of carnivores affecting both wild and domestic populations. The hemagglutinin gene, encoding for the attachment protein that determines viral tropism, shows high heterogeneity among strains, allowing for the distinction of ten different lineages distributed worldwide according to a geographic pattern. We obtained the sequences of the full-length H gene of 15 wild-type CDV strains circulating in domestic dog populations from the Aburrá Valley, Colombia. A phylogenetic analysis of H gene nucleotide sequences from Colombian CDV viruses along with field isolates from different geographic regions and vaccine strains was performed. Colombian wild-type viruses formed a distinct monophyletic cluster clearly separated from the previously identified wild-type and vaccine lineages, suggesting that a novel genetic variant, quite different from vaccines and other lineages, is circulating among dog populations in the Aburrá Valley. We propose naming this new lineage as "South America 3". This information indicates that there are at least three different CDV lineages circulating in domestic and wild carnivore populations in South America. The first one, renamed Europe/South America 1, circulates in Brazil and Uruguay; the second, South America 2, appears to be restricted to Argentina; and the third, South America 3, which comprises all the strains characterized in this study, may also be circulating in other northern countries of South America.

Asunto(s)

Virus del Moquillo Canino/clasificación , Moquillo/epidemiología , Hemaglutininas Virales/genética , Filogenia , Secuencia de Aminoácidos , Animales , Secuencia de Bases , Colombia/epidemiología , Moquillo/virología , Virus del Moquillo Canino/genética , Perros , Genotipo , Hemaglutininas/genética , Datos de Secuencia Molecular , Homología de Secuencia de Aminoácido , Tropismo Viral

RESUMEN

The 2009 pandemic influenza A(H1N1)pdm09 virus emerged and caused considerable morbidity and mortality in the third world, especially in Brazil. Although circulating strains of A(H1N1)pdm09 are A/California/04/2009-like (CA-04-like) viruses, various studies have suggested that some mutations in the viral hemagglutinin (HA) may be associated with enhanced severity and fatality. This phenomenon is particularly challenging for immunocompromised individuals, such as those who have undergone bone marrow transplant (BMT), because they are more likely to display worse clinical outcomes to influenza infection than non-immunocompromised individuals. We studied the clinical and viral aspects of post-BMT patients with confirmed A(H1N1)pdm09 diagnosis in the largest cancer hospital in Brazil. We found a viral strain with K-15E, P83S and Q293H polymorphisms in the HA, which is presumably more virulent, in these individuals. Despite that, these patients showed only mild symptoms of infection. Our findings complement the discovery of mild cases of infection with the A(H1N1)pdm09 virus with the K-15E, P83S and Q293H mutations in Brazil and oppose other studies that have linked these changes with increased disease severity. These results could be important for a better comprehension of the impact of the pandemic influenza in the context of BMT.

Asunto(s)

Trasplante de Médula Ósea , Subtipo H1N1 del Virus de la Influenza A/genética , Gripe Humana/patología , Mutación , Adolescente , Adulto , Animales , Estudios de Casos y Controles , Niño , Análisis Mutacional de ADN , Perros , Femenino , Hemaglutininas Virales/genética , Interacciones Huésped-Patógeno , Humanos , Huésped Inmunocomprometido , Subtipo H1N1 del Virus de la Influenza A/clasificación , Subtipo H1N1 del Virus de la Influenza A/fisiología , Gripe Humana/virología , Células de Riñón Canino Madin Darby , Masculino , Datos de Secuencia Molecular , Filogenia , Polimorfismo Genético , Índice de Severidad de la Enfermedad , Adulto Joven

RESUMEN

Canine distemper virus (CDV, Paramyxoviridae, Morbillivirus) is the causative agent of a severe infectious disease affecting terrestrial and marine carnivores worldwide. Phylogenetic relationships and the genetic variability of the hemagglutinin (H) protein and the fusion protein signal-peptide (Fsp) allow for the classification of field strains into genetic lineages. Currently, there are nine CDV lineages worldwide, two of them co-circulating in South America. Using the Fsp-coding region, we analyzed the genetic variability of strains from Uruguay, Brazil, and Ecuador, and compared them with those described previously in South America and other geographical areas. The results revealed that the Brazilian and Uruguayan strains belong to the already described South America lineage (EU1/SA1), whereas the Ecuadorian strains cluster in a new clade, here named South America 3, which may represent the third CDV lineage described in South America.

Asunto(s)

Virus del Moquillo Canino/genética , Virus del Moquillo Canino/aislamiento & purificación , Moquillo/virología , Variación Genética , Secuencia de Aminoácidos , Animales , Virus del Moquillo Canino/química , Virus del Moquillo Canino/clasificación , Perros , Hemaglutininas Virales/química , Hemaglutininas Virales/genética , Datos de Secuencia Molecular , Tipificación Molecular , Filogenia , Alineación de Secuencia , América del Sur

RESUMEN

Canine distemper virus (CDV) is a major pathogen of dogs and represents a serious threat to both unvaccinated and vaccinated animals. This study surveyed dogs with or without clinical signs related to canine distemper from different regions of Brazil from 2008 to 2012. A total of 155 out of 386 animals were found to be CDV positive by RT-PCR; 37 (23.8%) dogs were asymptomatic at the time of sampling, and 90 (58%) displayed clinical signs suggestive of distemper. Nineteen (12.2%) dogs had a record of complete vaccination, 15 (9.6%) had an incomplete vaccination protocol, and 76 (49%) had no vaccination record. Based on the sequence analysis of the complete hemagglutinin gene of 13 samples, 12 of the strains were characterized as Genotype South America-I/Europe. Considering criteria of at least 95% nucleotide identity to define a genotype and 98% to define a subgenotype, South America-I/Europe sequences segregated into eight different phylogenetically well-defined clusters that circulated or co-circulated in distinct geographical areas. Together, these findings highlight the relevance of CDV infection in Brazilian dogs, demonstrate the predominance of one genotype in Brazil and support the need to intensify the current control measures.

Asunto(s)

Portador Sano/veterinaria , Virus del Moquillo Canino/clasificación , Virus del Moquillo Canino/genética , Moquillo/virología , Enfermedades de los Perros/virología , Variación Genética , Animales , Brasil/epidemiología , Portador Sano/virología , Análisis por Conglomerados , Virus del Moquillo Canino/aislamiento & purificación , Perros , Femenino , Genotipo , Hemaglutininas Virales/genética , Masculino , Datos de Secuencia Molecular , Filogeografía , Análisis de Secuencia de ADN , Homología de Secuencia

RESUMEN

Canine distemper virus (CDV; Paramyxoviridae, Morbillivirus) is the etiologic agent of a multisystemic infectious disease affecting all terrestrial carnivore families with high incidence and mortality in domestic dogs. Sequence analysis of the hemagglutinin (H) gene has been widely employed to characterize field strains, permitting the identification of nine CDV lineages worldwide. Recently, it has been established that the sequences of the fusion protein signal-peptide (Fsp) coding region are extremely variable, suggesting that analysis of its sequence might be useful for strain characterization studies. However, the divergence of Fsp sequences among worldwide strains and its phylogenetic resolution has not yet been evaluated. We constructed datasets containing the Fsp-coding region and H gene sequences of the same strains belonging to eight CDV lineages. Both datasets were used to evaluate their phylogenetic resolution. The phylogenetic analysis revealed that both datasets clustered the same strains into eight different branches, corresponding to CDV lineages. The inter-lineage amino acid divergence was fourfold greater for the Fsp peptide than for the H protein. The likelihood mapping revealed that both datasets display strong phylogenetic signals in the region of well-resolved topologies. These features indicate that Fsp-coding region sequence analysis is suitable for evolutionary studies as it allows for straightforward identification of CDV lineages.

Asunto(s)

Virus del Moquillo Canino/clasificación , Sistemas de Lectura Abierta , Filogenia , Polimorfismo Genético , Señales de Clasificación de Proteína/genética , Proteínas Virales de Fusión/clasificación , Américas , Animales , Asia , Moquillo/virología , Virus del Moquillo Canino/genética , Virus del Moquillo Canino/aislamiento & purificación , Perros , Europa (Continente) , Hemaglutininas Virales/clasificación , Hemaglutininas Virales/genética , Filogeografía , Análisis de Secuencia de ADN , Proteínas Virales de Fusión/genética

RESUMEN

This study examined the phylogenetic relationship of strains of canine distemper virus (CDV) collected from Paraná State, Brazil, based on the hemagglutinin gene. Urine samples were collected from 4 dogs from northern Paraná State that demonstrated clinical manifestations of canine distemper. The participation of CDV was initially confirmed by RT-PCR targeting the nucleocapsid protein, after which the complete hemagglutinin gene was sequenced from each sample. Sequences were deposited in and compared with those already in GenBank. Phylogenetic analyses, using amino acid and nucleotide sequences based on the hemagglutinin gene, demonstrated that these strains of CDV are closely related to those from the Europe 1 lineage of CDV, with marked differences from other recognized geographical clusters of CDV isolates and from the vaccine strains. The strains of CDV from this region of southern Brazil appear to be related to those from Europe 1.

Asunto(s)

Virus del Moquillo Canino/genética , Genes Virales , Hemaglutininas Virales/genética , Filogenia , Brasil

RESUMEN

In 2011, vaccinia virus caused an outbreak of bovine vaccinia, affecting dairy cattle and dairy workers in Brazil. Genetic and phenotypic analyses identified this isolate as distinct from others recently identified, thereby reinforcing the hypothesis that different vaccinia virus strains co-circulate in Brazil.

Asunto(s)

Enfermedades de los Bovinos/epidemiología , Enfermedades de los Bovinos/virología , Brotes de Enfermedades/veterinaria , Virus Vaccinia/aislamiento & purificación , Vaccinia/veterinaria , Animales , Brasil/epidemiología , Bovinos , Línea Celular , Hemaglutininas Virales/genética , Humanos , Ratones , Filogenia , Vaccinia/epidemiología , Vaccinia/virología , Virus Vaccinia/clasificación , Virus Vaccinia/genética

RESUMEN

During the influenza pandemic of 2009, the number of viral pneumonia cases showed a marked increase in comparison with seasonal influenza viruses. Mutations at amino acid 222 (D222G mutations) in the virus hemagglutinin (HA) molecule, known to alter the receptor-recognition properties of the virus, were detected in a number of the more severely-affected patients in the early phases of the pandemic. To understand the background for the emergence of the mutant amino acid D222G in human lungs, we conducted histological examinations on lung specimens of patients from Mexico who had succumbed in the pandemic. Prominent regenerative and hyperplastic changes in the alveolar type II pneumocytes, which express avian-type sialoglycan receptors in the respiratory tract of severely affected individuals, were observed in the Mexican patients. An infection model utilizing guinea pigs, which was chosen in order to best simulate the sialic acid distribution of severe pneumonia in human patients, demonstrated an increase of D222G mutants and a delay in the diminution of mutants in the lower respiratory tract in comparison to the upper respiratory tract. Our data suggests that the predominance of avian-type sialoglycan receptors in the pneumonic lungs may contribute to the emergence of viral HA mutants. This data comprehensively illustrates the mechanisms for the emergence of mutants in the clinical samples.

Asunto(s)

Modelos Animales de Enfermedad , Hemaglutininas Virales/genética , Subtipo H1N1 del Virus de la Influenza A/genética , Gripe Humana/virología , Infecciones por Orthomyxoviridae/virología , Neumonía Viral/virología , Células Epiteliales Alveolares/virología , Animales , Brotes de Enfermedades , Femenino , Genes Virales , Cobayas , Interacciones Huésped-Patógeno , Humanos , Subtipo H1N1 del Virus de la Influenza A/patogenicidad , Gripe Humana/patología , Células de Riñón Canino Madin Darby , Mutación , Neumonía Viral/patología , ARN Viral/genética , Receptores de Superficie Celular/genética , Receptores de Superficie Celular/metabolismo , Receptores Virales/genética , Receptores Virales/metabolismo , Reacción en Cadena de la Polimerasa de Transcriptasa Inversa

RESUMEN

As part of our ongoing efforts on animal influenza surveillance in Argentina, an H9N2 virus was isolated from a wild aquatic bird (Netta peposaca), A/rosy-billed pochard/Argentina/CIP051-559/2007 (H9N2) - herein referred to as 559/H9N2. Due to the important role that H9N2 viruses play in the ecology of influenza in nature, the 559/H9N2 isolate was characterized molecularly and biologically. Phylogenetic analysis of the HA gene revealed that the 559/H9N2 virus maintained an independent evolutionary pathway and shared a sister-group relationship with North American viruses, suggesting a common ancestor. The rest of the genome segments clustered with viruses from South America. Experimental inoculation of the 559/H9N2 in chickens and quail revealed efficient replication and transmission only in quail. Our results add to the notion of the unique evolutionary trend of avian influenza viruses in South America. Our study increases our understanding of H9N2 viruses in nature and emphasizes the importance of expanding animal influenza surveillance efforts to better define the ecology of influenza viruses at a global scale.

Asunto(s)

Subtipo H9N2 del Virus de la Influenza A/aislamiento & purificación , Gripe Aviar/virología , Animales , Argentina/epidemiología , Pollos , Patos , Hemaglutininas Virales/genética , Subtipo H9N2 del Virus de la Influenza A/clasificación , Subtipo H9N2 del Virus de la Influenza A/genética , Gripe Aviar/epidemiología , Datos de Secuencia Molecular , Filogenia , Codorniz

RESUMEN

BACKGROUND: Highly pathogenic avian influenza A(H5N1) viruses are an important health problem in many Asian and African countries. The current increase in human cases demonstrates that influenza A(H5N1) is still a significant global pandemic threat. Many health organizations have recognized the need for new strategies to improve influenza global surveillance. Specifically, the World Health Organization through the global technical consultation for influenza surveillance have called for a detailed picture of the current limitations, especially at the nation level, to evaluate, standardize and strength reporting systems. The main goal of our study is to demonstrate the value of genetic surveillance as part of a strategic surveillance plan. As a proof of concept, we evaluated the current situation of influenza A(H5N1) in Asian and Africa. RESULTS: Our analysis revealed a power-law distribution in the number of sequences of A(H5N1) viruses analyzed and/or reported to influenza surveillance networks. The majority of the Asian and African countries at great risk of A(H5N1) infections have very few (approximately three orders of magnitude) sequenced A(H5N1) viruses (e.g. hemagglutinin genes). This suggests that countries under pandemic alert for avian influenza A(H5N1) have very limited participation (e.g. data generation, genetic analysis and data share) in avian influenza A(H5N1) surveillance. More important, this study demonstrates the usefulness of influenza genetic surveillance to detect emerging pandemic threat viruses. CONCLUSIONS: Our study reveals that some countries suffering from human cases of avian influenza have limited participation (e.g. genetic surveillance or data share) with global surveillance networks. Also, we demonstrate that the implementation of genetic surveillance programs could increase and strengthen worldwide epidemic and pandemic preparedness. We hope that this work promotes new discussions between policy makers and health surveillance organizations to improve current methodologies and regulations.

Asunto(s)

Hemaglutininas Virales/genética , Subtipo H5N1 del Virus de la Influenza A/genética , Gripe Aviar/epidemiología , Gripe Humana/epidemiología , Pandemias , Vigilancia de la Población/métodos , África/epidemiología , Animales , Asia/epidemiología , Aves , Humanos , Subtipo H5N1 del Virus de la Influenza A/aislamiento & purificación , Gripe Aviar/virología , Gripe Humana/virología , Organización Mundial de la Salud

RESUMEN

Canine distemper virus (CDV) is the etiological agent of a multisystemic infection that affects different species of carnivores and is responsible for one of the main diseases suffered by dogs. Recent data have shown a worldwide increase in the incidence of the disease, including in vaccinated dog populations, which necessitates the analysis of circulating strains. The hemagglutinin (H) gene, which encodes the major antigenic viral protein, has been widely used to determine the degree of genetic variability and to associate CDVs in different worldwide circulating lineages. Here, we obtained the sequence of the first full-length H gene of field South American CDV strains and compared it with sequences of worldwide circulating field strains and vaccine viruses. In South America, we detect two co-circulating lineages with different prevalences: the Europe 1 lineage and a new South America 2 lineage. The Europe 1 lineage was the most prevalent in South America, and we suggest renaming it the Europe 1/South America 1 lineage. The South America 2 lineage was found only in Argentina and appears related to wild CDV strains. All South American CDV strains showed high amino-acid divergence from vaccine strains. This genetic variability may be a possible factor leading to the resurgence of distemper cases in vaccinated dog populations.

Asunto(s)

Virus del Moquillo Canino/clasificación , Virus del Moquillo Canino/genética , Moquillo/virología , Filogenia , Animales , Análisis por Conglomerados , Moquillo/epidemiología , Virus del Moquillo Canino/aislamiento & purificación , Perros , Hemaglutininas Virales/genética , Epidemiología Molecular , Datos de Secuencia Molecular , Prevalencia , ARN Viral/genética , Análisis de Secuencia de ADN , América del Sur/epidemiología