Canine coronavirus, Greece. Molecular analysis and genetic diversity characterization

Abstract

Canine coronavirus (CCoV) is an etiologic agent of diarrhea in dogs and is known to have spread worldwide. Mild disease or asymptomatic carriage are probably in many cases common outcomes of infection. To date, two different genotypes of CCoV are known, CCoV type I (CCoV-I) and CCoV type II (CCoV-II). CCoV type II is divided in two subtypes, CCoV-IIa (classical strains) and CCoV-IIb, with CCoV-IIb emerging as a result of a putative recombination between CCoV-IIa and transmissible gastroenteritis virus (TGEV). The aim of the present study was to investigate the presence of CCoV in Greece and to genetically analyze the circulating strains. Between December 2007 and December 2009, 206 fecal samples were collected from dogs with diarrhea from kennels, pet shops and veterinary clinics of different country regions. RT-PCR and real time RT-PCR assays were used for CCoV detection and characterization. CCoV was identified in 65.1% of the dogs presenting diarrhea, being more frequently detected in animals younger than 3 months old and in animals housed in groups. In 47% of the positive samples more than one CCoV genotype/subtype were detected, with triple CCoV-I/CCoV-IIa/CCoV-IIb infections being identified for the first time. Molecular and phylogenetic analysis revealed that CCoV-I Greek strains share low genetic relatedness to each other and to the prototype CCoV-I strains in the 5' end of the S gene. Moreover, a divergent CCoV-IIa strain was identified. The circulation of highly variable CCoV-I and CCoV-IIb emerging strains, as well as the detection of the divergent strain, raise concerns on the importance of these new strains as primary pathogens of diarrhoeic syndromes diagnosed in dogs.

Molecular characterization of canine coronavirus strains circulating in Brazil

“…In the past decade, several researchers have studied the importance of CCoV as an agent of diarrhea in puppies Le Poder, 2011;Ntafis et al, 2013;Pratelli, 2011;Stavisky et al, 2012). In Brazil, despite the availability of safe and effective vaccines, CPV is considered the most common viral agent associated with enteritis in puppies (Castro et al, 2010b(Castro et al, , 2011.…”

“…As a result, the CCoV-II genotype was divided into two subtypes, CCoV-IIa (classical strains) and IIb (TGEV-like strains) (Decaro et al, 2009(Decaro et al, , 2010. Infection may occur with a single strain, but the two CCoV genotypes are commonly detected simultaneously in the same dog (Decaro et al, 2005(Decaro et al, , 2009Erles and Brownlie, 2009;Ntafis et al, 2013;Pratelli et al, 2004a;Pratelli, 2011) Since the first reports in 1971 (Binn et al, 1974), CCoV infection has been associated with mild cases of diarrhea. Clinical signs can range from moderate to severe, depending on whether the infection occurs in combination with other pathogens such as canine parvovirus (CPV), canine distemper virus or canine adenovirus type I (Decaro et al, 2004(Decaro et al, , 2007aPratelli et al, 1999aPratelli et al, , 2001.…”

“…Epidemiological investigations have revealed that CCoVs have spread worldwide (Decaro et al, 2009Erles & Brownlie, 2009;McElligott et al, 2011;Naylor et al, 2001;Ntafis et al, 2013;Stavisky et al, 2012). Serological studies conducted in southern Brazil revealed the presence of antibodies to this virus in 45-50% of dogs, indicating that CCoVs are already widespread in the canine population (Castro et al, 2010a;Dezengrini et al, 2007).…”

Canine coronavirus infection in dogs in Turkey: Virologicaland serological evidence

“…CCoV infection have been reported from different countries Turkey (Gur et al, 2008), Italy , Greece (Ntafis et al, 2012), Belgium (Zicola et al, 2012), and detection has been reported from different specimens such as intestinal system (Keenan et al, 1976), feces (Battersby and Harvey, 2006;Ntafis et al, 2013;Costa et al, 2014), and internal organs like liver, lung, mesenteric lymph node and thymus (Ntafis et al, 2013). CCoV viral RNA detection from blood sample was reported by Decaro et al (2010) from one experimentally infected by CB/05 on dog (Decaro and Buonavoglia, 2011) during viremia.…”

“…To date, two different genotypes of CCoV are known, CCoV type I (CCoV-I) and CCoV type II (CCoV-II). CCoV type II is divided in two subtypes, CCoV-IIa (classical strains) and CCoV-IIb, with CCoV-IIb emerging as a result of a putative recombination between CCoV-IIa and transmissible gastroenteritis virus (TGEV) (Ntafis et al, 2013). Different serologic (indirect ELISA, microneutralization) (Mochizuki et al, 1987;Tuchiya et al, 1991;Elia et al, 2003;Buonavoglia et al, 2006;Le Poder, 2011) and virologic (direct ELISA, cell culture, direct immunofluorescence) diagnostic methods are widely used to detect the genotypes of CCoV (Costa et al, 2014).…”