The geographic distribution of the CCoV types and subtypes is reported in Table 1.
After RT-PCR with primer pair N3SN/R3AS, CCoV and FCoV reference strains yielded an amplicon >1,000 bp, with the exception of TGEV-like CCoV 341/05, which gave a 929-bp product as a consequence of a 154-nt deletion in ORF7b (14).
All 20 samples that were positive according to the CCoV-IIb-specific assay and negative according to the CCoV-I TaqMan assay were confirmed to contain true CCoV strains because they yielded RT-PCR products considerably larger than the 367-bp amplicon obtained from TGEV.
The best identities among CCoV-IIa isolates were to strain Insavc-1, which has been proposed as intermediate virus between CCoV and TGEV (26) and to the more recent pantropic strain CB/05 (11) in the 5' and 3' ends, respectively.
The TGEV-like CCoVs from the United Kingdom formed a unique clade, whereas the strains detected in eastern Europe were mixed with CCoV-IIb viruses from Italy.
A CCoV strain displaying close relatedness to porcine CoVs in the N-terminus of the spike protein, which is related to porcine CoVs, was isolated [approximately equal to] 20 years ago, but the subsequent molecular characterization was restricted to the 5' end of the spike gene (19).
However, the prevalence of this CCoV subtype differed by geographic origin of the samples; the highest detection rates (96.
With the exception of strain UCD1, analysis of archival samples found the oldest TGEV-like strain in 2001, about 4 years before this CCoV subtype was reported in Italy (14).
Distribution of CCoV genotypes and TGEV-like strains (CCoV-IIb) in dogs in European countries, 2001-2008 * No.
To assess the distribution of the TGEV-like CCoVs in canine populations of different geographic areas of Europe, we used a subtype IIb-specific reverse transcription--PCR (RT-PCR) assay.
Development of RT-PCRs Specific for Classical and TGEV-like CCoVs