Variation of the sequence in the gene encoding for transmembrane protein M of canine coronavirus (CCV)

Abstract

A nucleotide variability in the sequence of the gene encoding for the transmembrane protein M of canine coronavirus (CCV) is described. A total of 177 faecal samples from pups with enteritis were analysed by a PCR and n-PCR specific for CCV. Four samples, collected from a dog presenting a long-duration shedding of CCV, and a sample from another diarrhoeic dog, were found positive by PCR but negative by n-PCR. Sequence analysis of the samples revealed silent nucleotide substitutions in the binding site of the internal primer used for the n-PCR. Moreover, the nucleotide substitutions occurring over the whole fragment of the five samples analysed were similar.

SARS Coronavirus Detection

“…However, the genomes of RNA viruses, including those of coronaviruses, tend to vary over time and with location (9–12). Recently, the sequence variations of SARS-CoV during the first epidemic phases in China in 2003 were reported.…”

Genetic evolution of canine coronavirus and recent advances in prophylaxis

“…In the meantime, by sequence analysis of CCoV detected in faecal samples collected from diarrheic dogs in the South of Italy, multiple nt substitutions accumulating over a fragment of the M gene, were observed [26]. These preliminary observations gave a meaningful impulse to the study of the CCoV genetic evolution.…”

“…Although CCoV infections appear to be a minor cause of life-threatening enteritis in dogs, severe illness as a consequence of dual infections has been observed [3,11,27,46]. Since polymicrobial infections are common in high-density populations, such as in unvaccinated kennels, and knowing that some dogs shed the virus for periods as long as 6 months after clinical signs have ceased [26,29], it seems likely that the immunisation of dogs that would produce a sterilising immunity against CCoV, would have beneficial epidemiological effects. Moreover, as a consequence of the relatively high mutation frequency, the RNA viruses have the potential to rapidly adjust to certain negative pressures, such as those presented by the immune system.…”

“…Production of local antibodies (IgAs) restricts the spread of the virus within the intestine and arrests the progress of infection. Infected dogs generally shed CCoV in the faeces for 6-9 days post infection [16], but some naturally infected dogs have shed virus for a period as long as 6 months after clinical signs had ceased [26,29].…”

High‐cell‐passage canine coronavirus vaccine providing sterilising immunity

“…In young pups, or when the virus occurs with concurrent pathogens, diarrhoea may be severe with dehydration, loss of appetite and even death (Appel 1987). Infected dogs generally shed CCoV in their faeces for six to nine days after infection (Keenan and others 1976), although the virus has been detected in faeces up to six months after clinical signs have ceased (Pratelli and others 2001a, 2002b, Pratelli 2006). CCoV is highly contagious, and once the virus is established in a kennel, the spread of the infection is difficult to control.…”