Genotype-specific fluorogenic RT-PCR assays for the detection and quantitation of canine coronavirus type I and type II RNA in faecal samples of dogs.
Two genotype-specific fluorogenic RT-PCR assays were developed for the detection and quantitation of canine coronavirus (CCoV) type I and type II RNA in the faeces of dogs with diarrhoea. Both the fluorogenic assays showed high specificity, sensitivity and reproducibility, allowing a precise quantitation of CCoV type I and type II RNA over a linear range of about eight orders of magnitude (from 10(1) to 10(8) copies of standard RNA). Comparison with genotype-specific gel-based RT-PCR assays revealed that the fluorogenic assays were more sensitive and more rapid than conventional amplifications, with a large increase in throughput. The genotype-specific fluorogenic assays were then used to detect and measure viral loads in the faecal samples collected from dogs naturally or experimentally infected with type I, type II, or both genotypes. Of 174 samples collected from naturally infected dogs, 77 were positive for CCoV type I and 46 for CCoV type II. Thirty-eight dogs were found to be infected naturally by both genotypes, with viral RNA titres generally higher for type I in comparison to type II. At the same time, dogs infected experimentally shed type I RNA with higher titres with respect to type II.
Decaro
Nicola
N
Department of Animal Health and Well-being, Faculty of Veterinary Medicine of Bari, Strada prov per Casamassima Km 3, 70010 Valenzano, Bari, Italy. n.decaro@veterinaria.uniba.it
Martella
Vito
V
Ricci
Dominga
D
Elia
Gabriella
G
Desario
Costantina
C
Campolo
Marco
M
Cavaliere
Nicola
N
Di Trani
Livia
L
Tempesta
Maria
M
Buonavoglia
Canio
C
D000818:Animals; D018352:Coronavirus Infections / Q000175:diagnosis / Q000662:veterinary*; D017939:Coronavirus, Canine / Q000235:genetics / Q000302:isolation & purification*; D003967:Diarrhea / Q000175:diagnosis / Q000662:veterinary*; D004283:Dog Diseases / Q000175:diagnosis*; D004285:Dogs; D005243:Feces / Q000821:virology; D005453:Fluorescence; D007558:Italy; D012367:RNA, Viral / Q000032:analysis*; D015203:Reproducibility of Results; D020133:Reverse Transcriptase Polymerase Chain Reaction; D012680:Sensitivity and Specificity; D013045:Species Specificity
D012367:RNA, Viral