RESUMO
Our study identified strains of the A/H5N1 virus in analyzed samples of subsistence poultry, wild birds, and mammals, belonging to clade 2.3.4.4b, genotype B3.2, with very high genetic similarity to strains from Chile, Uruguay, and Argentina. This suggests a migratory route for wild birds across the Pacific, explaining the phylogenetic relatedness. The Brazilian samples displayed similarity to strains that had already been previously detected in South America. Phylogeographic analysis suggests transmission of US viruses from Europe and Asia, co-circulating with other lineages in the American continent. As mutations can influence virulence and host specificity, genomic surveillance is essential to detect those changes, especially in critical regions, such as hot spots in the HA, NA, and PB2 sequences. Mutations in the PB2 gene (D701N and Q591K) associated with adaptation and transmission in mammals were detected suggesting a potential zoonotic risk. Nonetheless, resistance to neuraminidase inhibitors (NAIs) was not identified, however, continued surveillance is crucial to detect potential resistance. Our study also mapped the spread of the virus in the Southern hemisphere, identifying possible entry routes and highlighting the importance of surveillance to prevent outbreaks and protect both human and animal populations.
Assuntos
Surtos de Doenças , Virus da Influenza A Subtipo H5N1 , Influenza Aviária , Filogenia , Filogeografia , Animais , Brasil/epidemiologia , Influenza Aviária/virologia , Influenza Aviária/epidemiologia , Virus da Influenza A Subtipo H5N1/genética , Virus da Influenza A Subtipo H5N1/classificação , Virus da Influenza A Subtipo H5N1/isolamento & purificação , Aves/virologia , Mamíferos/virologia , Aves Domésticas/virologia , Humanos , Genótipo , Neuraminidase/genética , Proteínas Virais/genética , Mutação , Animais Selvagens/virologiaRESUMO
The aim of this study was standardization and application of polymerase chain reaction (PCR) for the detection of contaminants in cell cultures, sera and trypsin. Five PCR protocols were standardized to assess the presence of genetic material from mycoplasma, porcine circovirus 1 (PCV1), bovine leukemia virus (BLV) or bovine viral diarrhea virus (BVDV) in cell culture samples. PCR reactions for the genes GAPDH and beta-actin were used to evaluate the efficiency of nucleic acid extraction. The PCR protocols were applied to 88 cell culture samples from eight laboratories. The tests were also used to assess potential contamination in 10 trypsin samples and 13 fetal calf serum samples from different lots from five of the laboratories. The results showed the occurrence of the following as DNA cell culture contaminants: 34.1% for mycoplasma, 35.2% for PCV1, 23.9% for BVDV RNA and 2.3% for BLV. In fetal calf sera and trypsin samples BVDV RNA and PCV1 DNA was detected. The results demonstrated that cell culture, sera and trypsin used by different laboratories show a high rate of contaminants. The results highlight the need for monitoring cell cultures and controlling for biological contaminants in laboratories and cell banks working with these materials.
Assuntos
Soro/microbiologia , Soro/virologia , Tripsina/análise , Animais , Bovinos , Linhagem Celular , Células Cultivadas , Circovirus/genética , DNA Bacteriano/genética , DNA Bacteriano/isolamento & purificação , DNA Viral/genética , DNA Viral/isolamento & purificação , Vírus da Diarreia Viral Bovina Tipo 1/genética , Contaminação de Medicamentos , Humanos , Laboratórios/normas , Laboratórios/estatística & dados numéricos , Vírus da Leucemia Bovina/genética , Mycoplasma/genética , Infecções por Mycoplasma/sangue , Infecções por Mycoplasma/microbiologia , Reação em Cadeia da Polimerase/métodos , RNA Viral/genética , RNA Viral/isolamento & purificação , Reprodutibilidade dos Testes , Suínos , Viroses/sangue , Viroses/virologiaRESUMO
Seneca Valley virus (SVV) is a non-enveloped RNA virus and the only member of the Senecavirus A (SVA) species, in the Senecavirus genus, Picornaviridae family. SVV infection causes vesicular lesions in the oral cavity, snout and hooves of pigs. This infection is clinically indistinguishable from trade-restrictions-related diseases such as foot-and-mouth disease. Other clinical manifestations include diarrhoea, anorexia, lethargy, neurological signs and mortality in piglets during their first week of age. Before this study, Chile was considered free of vesicular diseases of swine, including SVV. In April 2022, a suspected case of vesicular disease in a swine farm was reported in Chile. The SVV was confirmed and other vesicular diseases were ruled out. An epidemiological investigation and phylogenetic analyses were performed to identify the origin and extent of the outbreak. Three hundred ninety-five samples from 44 swine farms were collected, including faeces (208), oral fluid (28), processing fluid (14), fresh semen (61), environmental samples (80) and tissue from lesions (4) for real-time RT-PCR detection. Until June 2022, the SVV has been detected in 16 out of 44 farms, all epidemiologically related to the index farm. The closest phylogenetic relationship of the Chilean SVV strain is with viruses collected from swine in California in 2017. The direct cause of the SVV introduction has not yet been identified; however, the phylogenetic analyses suggest the USA as the most likely source. Since the virus remains active in the environment, transmission by fomites such as contaminated feed cannot be discarded. Further studies are needed to determine the risk of the introduction of novel SVV and other transboundary swine pathogens to Chile.