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Enteric viruses play an important role in the Brazilian poultry industry due to the economic impact of resulting low yields of broilers, layers, and breeders. The most common enteric viruses affecting commercial flocks in Brazil include Fowl Adenovirus of group I (FAdV-I), Chicken Parvovirus (ChPV), Chicken Astrovirus (CAstV), Avian Nephritis Virus (ANV), Infectious Bronchitis Virus (IBV), Avian Reovirus (AReo), and Avian Rotavirus (ARtV). The aim of this study was to identify single and multiple infections using data obtained from 270 samples from eleven Brazilian states, corresponding to the period between 2010 and 2017. This was accompanied by an analysis of the relationship between the age of birds, clinical signs, and geographical distribution, using Polymerase Chain Reaction (PCR) and Reverse Transcription-PCR (RT-PCR) techniques. Twenty-five profiles of virus combinations were detected. Single infections were encountered in 86.3% of samples, and multiple infections were present in the remaining 13.7%. Both single and multiple infections affected all kinds of commercial chickens with digestive problems, stunting syndrome, decreases in egg and meat production, increased mortality, and respiratory signs. FAdV-I, ChPV, CAstV, ANV, and ARtV were mostly detected in young broilers, in contrast with IBV, which was detected in hens from one to greater than 51 weeks of age. These results exhibit the complexity of enteric diseases and the still poorly understood role of each pathogen as a unique etiological agent.

AimThe objective of this study was to determine the presence of the variants of canine parvovirus (CPV)-2 in the city of Quito, Ecuador, due to the high domestic and street-type canine population, and to identify possible mutations at a genetic level that could be causing structural changes in the virus with a consequent influence on the immune response of the hosts.Materials and MethodsThirty-five stool samples from different puppies with characteristic signs of the disease and positives for CPV through immunochromatography kits were collected from different veterinarian clinics of the city. Polymerase chain reaction and DNA sequencing were used to determine the mutations in residue 426 of the VP2 gene, which determines the variants of CPV-2; in addition, four samples were chosen for complete sequencing of the VP2 gene to identify all possible mutations in the circulating strains in this region of the country.ResultsThe results revealed the presence of the three variants of CPV-2 with a prevalence of 57.1% (20/35) for CPV-2a, 8.5% (3/35) for CPV-2b, and 34.3% (12/35) for CPV-2c. In addition, complete sequencing of the VP2 gene showed amino acid substitutions in residues 87, 101, 139, 219, 297, 300, 305, 322, 324, 375, 386, 426, 440, and 514 of the three Ecuadorian variants when compared with the original CPV-2 sequence.ConclusionThis study describes the detection of CPV variants in the city of Quito, Ecuador. Variants of CPV-2 (2a, 2b, and 2c) have been reported in South America, and there are cases in Ecuador where CVP-2 is affecting even vaccinated puppies.

Marek’s disease virus (MDV) and the reticuloendotheliosis virus (REV) are two of the primary oncogenic viruses that significantly affect chickens. In Brazil, there have been no previous published reports on the presence of field REV alone or in coinfection. This retrospective study analyzes samples from a case of lymphoproliferative lesions from a backyard chicken flock. MDV and REV were detected by PCR and classified as MDV1 and REV3, respectively, through sequencing and phylogenetic analysis based on the glycoprotein B (gB) genes for MDV and the polymerase (pol) and envelope (env) genes for REV. Real-time PCR reactions were performed for MDV to rule out the presence of the Rispens vaccine strain. This is the first report of the presence of REV in coinfection with a MDV clinical case in Brazil and the first molecular characterization of REV in South America. This study highlights the importance of molecular diagnosis for REV and MDV in poultry. In addition, this study highlights the distribution of these two viruses worldwide and the latent risk of them solely or in coinfection to this part of the world.

Avian adenovirus has been reported in many countries and is an infectious agent related with inclusion body hepatitis, hepatitis-hydropericardium syndrome (HHS), and respiratory and enteric conditions in chickens worldwide. The objective of this study was to detect and establish the molecular sequences of the hexon gene from the avian adenovirus strains of group I (FAdV-I) isolated from birds with hepatitis-hydropericardium syndrome (HHS), malabsorption syndrome and runting-stunting syndrome, to characterize the serotype of virus affecting commercial flocks in Brazil. Molecular characterization was performed by polymerase chain reaction (PCR), using specific primers to amplify the Loop 1 (L1) variable region of the gene in the FAdV-I genome and subsequent sequencing of the PCR product for each positive sample. The results have revealed the presence of the FAdV-8a, FAdV-8b, and FAdV-11 serotypes circulating in Brazilian chicken flocks. Phylogenetic analysis grouped these sequences into three (3) distinct groups, 14 samples were aligned with the FAdV-11 group, three (3) samples in the FAdV-8b group and one (1) sample in the FAdV-8a group. The serotypes FAdV-8a, FAdV-8b, and FAdV-11 are circulating in Brazilian chicken flocks. Therefore, these results are very important for improvement biosecurity measurements and vaccine production.

Reticuloendotheliosis virus (REV) is a retroviral pathogen capable of infecting several avian hosts and is associated with immunosuppression, anemia, proventriculitis, neoplasia, and runting–stunting syndrome. Its genome contains the three major genes, gag, pol, and env, and two flanking long terminal repeat (LTR) regions. Complete genome sequences of REV are limited in terms of geographical origin. The aim of this study was to characterize the complete genome of REV detected in Brazilian chickens with multiple viral coinfections and analyze the polymorphisms in the deduced amino acids sequences corresponding to its encoded proteins. We tested the presence and completeness of REV as well as other viral pathogens in samples from Brazilian poultry farms by qPCR. The complete genomes of two REV strains were sequenced by overlapping fragments through the dideoxy method. Phylogenetic analysis, pairwise identity matrix, polymorphism identification and protein modeling were performed along the entire genome. We detected REV in 65% (26/40) of the tested samples. Concomitant viral infections were detected in 82.5% (33/40) of the samples and in 90% (9/10) of the farms. Multiple infections included up to seven viruses. Phylogenetic analysis classified both Brazilian strains into REV subtype 3, and the pairwise comparison indicated that strains from the USA and fowlpox virus (FWPV)-related strains were the most identical. The subdomain p18 in gag, the reverse transcriptase/ribonuclease H in pol, and the surface (SU) in the env protein were the most polymorphic in genomic comparisons. The relevant motifs for each protein were highly conserved, with fewer polymorphisms in the fusion peptide, immunosuppression domain, and disulfide bonds on the surface (SU) and transmembrane (TM) of env. This is the first study to include complete genomes of REV in Brazil and South America detected in farms with multiple viral coinfections. Our findings suggest an involvement of REV as an immunosuppressor and active agent in the emergence and progression of multiple infectious diseases. We also found a possible etiological relationship between Brazilian strains and the USA and FWPV recombinant strains. This information highlights the need for epidemiological vigilance regarding REV in association with another pathogens.

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is a common epitheliotropic disease caused by the Fowlpox virus (FPV) in different fowl species. The agent is classified as a double-stranded DNA virus belonging to the genus Avipoxvirus within the family Poxviridae (Fenner, Pereira, Porterfield, Joklik, & Downie, 1974). The economic impact of Fowlpox on poultry farming is due to a potential reduction in egg production, a retarded growth rate, poor weight gain, medium to high morbidity and low mortality. It is present throughout the world and is characterized by proliferative nodular lesions on the comb, wattle, eyelids and some non-feathered parts of the bird in its cutaneous form or proliferative necrotic lesions in the respiratory tract (mouth, oesophagus, trachea) in its diphtheritic form (Nair, Zavala, & Fadly, 2013). Vectors such as insects and mites can also transmit FPV. There are reports of more than 200 species of birds infected by avipoxviruses (Bolte, Meurer, & Kaleta, 1999). Despite maintaining essential aspects common among all poxviruses, there are marked differences at the antigenic, immunological, genomic and biological levels (Afonso et al., 2000; Reed & Fatunmbi, 1993). The FPV genome size is approximately 288 kb and