Molecular analysis of canine circovirus in dogs from animal shelters in Belém, Pará, northern Brazil: first detection at the amazon region

The canine circovirus (CanCV) is a single-stranded DNA virus that has become an important emerging virus associated with gastroenteritis in dogs worldwide. In the present study, the CanCV was detected by PCR in 15% (22/147) of dogs from animal shelters in Belém, between 2019 and 2020. We observed an association between the CanCV infection and the presence of diarrhea in animals younger than one year of age (p > 0.01). The Brazilian strains were grouped in Chinese genotypes, with 99.54 to 100% nucleotilde homology. The GMRF Bayesian Skyride used the molecular clock model, which was the best suited technique to plot the dataset. The most recent common ancestor (TMRCA) was estimated in 2017, with the evolution rate of 1.6 x 10-3 s/s/y. The viral family diversity was also investigated, with emphasis on the families of the enteric pathogenic viruses Parvoviridae, Picornaviridae and Astroviridae, which were detected in the CanCV positive pooled samples. This study highlights the importance of the CanCV as an emergent virus that causes diarrhea in Brazilian dogs. The results found herein contribute to the understanding of the role of CanCV in enteric diseases and in the evolutionary molecular characterization of the circulating genotypes. Furthermore, we increased the understanding of the fecal virome in dogs with diarrhea, providing data for the monitoring and prevention viral gastroenteric diseases in domestic animals.

Detection of G3 human-like rotavirus in institutionalized dogs from Brazil

Viral gastroenteritis is a common clinical problem in dogs and group A rotavirus (RVA) is one of the agents involved in this etiology. It mainly affects dogs in the first 6 months of life, and these animals are considered an important reservoir and potential transmitters of the virus to other susceptible hosts, such as humans. Among the different types of RVA, G3 is the most detected in dogs, and this genotype is also involved in infections in other animals, including humans. Thus, the present study aims to investigate the presence of RVA in samples of dogs from a public kennel. A total of 64 fecal samples from dogs with diarrhea were analyzed, collected from April 2019 to March 2020, from the kennel of the Zoonosis Control Center, located in Belém, a city in the North of Brazil. The extracted genetic material was subjected to reverse transcription followed by real-time PCR (RT-qPCR); the positives were tested by RT-PCR with a specific primer for the RVA VP7 gene, after nucleotide sequencing and phylogenetic analysis. One sample was subjected to high-performance sequencing. A positivity of 7.8% (5/64) was observed for RVA, all characterized as G3, grouping in the G3-III lineage, with greater similarity to human samples. Different regions of the RVA genome fragments were found. These results emphasize the need for animal health surveillance to better understand the global strain dispersion of RVA and elucidate possible interspecies transmission events, monitoring the genetic diversity of this pathogen.

Occurrence of norovirus genogroups I and II in recreational water from four beaches in Belém city, Brazilian Amazon region

This study aimed to investigate the presence of norovirus (NoV) in recreational waters of four estuarine beaches located in Mosqueiro Island, Belém city, Brazilian Amazon, during two years of monitoring (2012 and 2013). NoV particles were concentrated on filtering membrane by the adsorption-elution method and detected by semi-nested RT-PCR (reverse transcription polymerase chain reaction) and sequencing. NoV positivity was observed in 37.5% (39/104) of the surface water samples, with genogroup GI (69.2%) occurring at a higher frequency than GII (25.7%), with a cocirculation of both genogroups in two samples (5.1%). This virus was detected in all sampling points analyzed, showing the highest detection rate at the Paraíso Beach (46.2%). Statistically, there was a dependence relationship between tide levels and positive detection, with a higher frequency at high tide (46.7%) than at low tide (25%) periods. Months with the highest detection rates (April 2012 and April/May 2013) were preceded by periods of higher precipitation (March 2012 and February/March 2013). Phylogenetic analysis showed the circulation of the old pandemic variant (GII.4-US_95-96) and GI.8. The NoV detection demonstrated viral contamination on the beaches and evidenced the health risk to bathers, mainly through recreational activities such as bathing, and highlighted the importance of including enteric viruses research in the recreational water quality monitoring.