Molecular Screening and Characterization of Canine Coronavirus Types I and II Strains from Domestic Dogs in Southern Italy, 2019–2021

Figure 4

Maximum-likelihood tree based on the 5^′-end of the S gene sequences (706 nt) of CCoV-IIa strains analysed in this study (indicated by black dots) and reference strains. Groups including reference CCoV-IIb (341/05, EU856361; 119/08, EU924791; CCoV/NTU336/F/2008, GQ477367; 430/07, EU924790; 174/06, EU856362; UCD-1, AF116248), TGEV (Purdue, DQ811789; TS, DQ201447), FCoV-I (Black, EU186072; UCD1, AB088222), and CCoV-I (23/03, AY307021; Elmo/02, AY307020; A76, JN856008) strains are collapsed as indicated. The phylogenetic tree was built with the maximum-likelihood method and the general time reversible model with a discrete gamma distribution (bootstrap 1,000 replicates; bootstrap values greater than 60 are shown). Reference sequences are indicated with strain name, country and year of collection, and accession number.