Detecção molecular e análise filogenética do gene H de amostras do vírus da cinomose canina em circulação no município de Campinas, São Paulo

Molecular analysis of the full-length F gene of Brazilian strains of canine distemper virus shows lineage co-circulation and variability between field and vaccine strains

Canine distemper is a highly contagious systemic viral disease, with worldwide distribution that affects a wide variety of terrestrial carnivores. This study characterized full-length fusion (F) genes from 15 Brazilian wild-type canine distemper virus (CDV) strains collected between 2003-2004 (n = 6) and 2013-2016 (n = 9). Using deduced amino acid (aa) sequence analysis, 14 strains were classified into Europe 1/South America 1 (EU1/SA1) lineage, with a temporal clustering into past (2003-2004) and contemporary (2013-2016) strains. One strain clustered to Rockborn-like lineage, showing high similarity (98.5%) with the Rockborn vaccine strain. In analyzed strains, the fusion protein signal-peptide (Fsp) coding region was highly variable at the aa level (67.4%-96.2%). The Brazilian strains were more Fsp-divergent from the North America 1 (NA1) strains (24.5%-36.3%) than from the Rockborn (11.2%-14.9%) vaccine strain. Seventeen cysteine residues in the full-length F gene and four non-conserved glycosylation sites in the Fsp region were detected. The results reveal that past and contemporary CDV strains are currently co-circulating. This first analysis of full-length F genes from Brazilian wild-type CDV strains contributes to knowledge of molecular epidemiology of CDV viral infection and evolution.

Canine Distemper Virus in Wild Felids of Costa Rica

Several highly infectious diseases can be transmitted through feces and cause elevated mortality among carnivore species. One such infectious agent, canine distemper virus (CDV; Paramyxoviridae: Morbillivirus), has been reported to affect wild carnivores, among them several felid species. We screened free-ranging and captive wild carnivores in Costa Rica for CDV. Between 2006 and 2012, we collected 306 fecal samples from 70 jaguars (Panther onca), 71 ocelots ( Leopardus pardalis ), five jaguarundis (Puma yaguaroundi), 105 pumas ( Puma concolor ), five margays ( Leopardus wiedii ), 23 coyotes ( Canis latrans ), and 27 undetermined Leopardus spp. We found CDV in six individuals: one captive jaguarundi (rescued in 2009), three free-ranging ocelots (samples collected in 2012), and two free-ranging pumas (samples collected in 2007). Phylogenetic analyses were performed using sequences of the phosphoprotein (P) gene. We provide evidence of CDV in wild carnivores in Costa Rica and sequence data from a Costa Rican CDV isolate, adding to the very few sequence data available for CDV isolates from wild Central American carnivores.

Genotyping of canine distemper virus strains circulating in Brazil from 2008 to 2012

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.