1,721,145 research outputs found
Genetic evolution of canine coronavirus and recent advances in prophylaxis
No full textSince the first identification of the virus in 1971, the disease caused by canine
coronavirus (CCoV) has not been adequately investigated and the role that the virus plays in canine
enteric illness has still not been well established. In the last decade, as a consequence of the
relatively high mutation frequency of RNA positive stranded viruses, CCoV has evolved and a new
genotype has been identified in the faeces of infected dogs. The several studies carried out by
different researchers have focused upon the epidemiological relevance of these viruses and,
considering the wide diffusion of CCoV infections among dog populations, the author underlines
the need for further investigation on the biology of CCoV and on the pathogenetic role of their
infections
Recenti acquisizioni sulle caratteristiche biologiche, diagnostiche e di profilassi del coronavirus del cane
No full textDisease caused by canine coronavirus (CCoV) too date has not been adequately investigated and the actual role that the virus plays in canine enteric illness has not still well established. CCoV was first isolated in Germany from pups with diarrhea and in the last decade CCoV has evolved and a new genotype has been identified in the faeces of the infected dogs. Moreover, it has been largely demonstrated that CCoV infection in dogs is frequently characterized by the simultaneous presence of both viruses. All these data underline both the necessity for further investigations on the pathogenetic role of CCoV infections and the necessity to develop an accurate prophylaxis program to control the infection
A high cell passages canine coronavirus vaccine for the immunization of dogs.
No full textThe efficacy of a high cell passages (hcp) canine coronavirus (CCoV) vaccine was evaluated for the immunization of dogs. Three dogs, previously tested and resulted seronegative and virus negative for CCoV, was inoculated twice at 21 days intervals with 4 ml of the hcp-CCoV vaccine and kept under observation for any adverse reactions. Two control dogs, sero- and virus-negative, were maintained non-vaccinated. The safety of the vaccine was tested in two further dogs inoculated by oro-nasal route with 10 times the vaccinal dose. During the observation period these dogs did not display any local or systemic reaction. Following the first and second vaccination, faecal samples were collected daily from the three dogs and fourteen days later the second inoculation the vaccinated and the two controls dogs were challenged with a field CCoV strain. Blood samples for serology were collected at T0 and weekly after vaccinations and after challenge. After the first and the second inoculations, the virus was not detected in faecal samples by both virus isolation (VI) and PCR assay. After challenge, the vaccinated dogs did not display clinical signs and virus shedding was not observed. The two control dogs displayed moderate clinical signs and the virus was detected by VI for 14.5 median days, by PCR assay for 23 median days. The present study has demonstrated the efficacy of the hcp CCoV vaccine in preventing the infection of dogs and, in particular its ability to induce a strong protective and long-lived immunity to infection
Comparison of serologic techniques for the assessment of antibodies against feline coronaviruses in Italy
No full textFeline coronaviruses, FCoVs, can be distinguished into serotypes I and II on the basis of the serological correlation with canine coronavirus. Type I viruses represent the genuine FCoVs and grow poorly in cell culture. Type II viruses proliferate well in vitro and accounts for only 20-30% of FCoV infections. FCoVs are ubiquitous in cat populations with a particularly high prevalence in catteries. As no information was available about the occurrence of FCoVs antibodies in Italian cats, investigations were performed in the Southern of Italy. One hundred sera collected from cats belonging to catteries or community shelters and to households in the region of Apulia were tested for FCoV type I and II antibodies. The virus neutralization, VN test was performed and compared with IFA and ELISA. Eighty sera that tested positive for FCoVs with the VN were also ELISA positive. Interestingly, ELISA, developed with FCoV type II antigen, revealed two more positive sera than did the VN test and four more positive sera than IFA did. All the results were confirmed by western blotting. ELISA proved to be substantially more sensitive and detected a FCoVs seroprevalence of 82%. Considering the cross-reactivity of FCoVs type I and type II, the ELISA developed in the present study was able to detect antibodies against both serotypes, allowing to employ the test as gold standard for the screening of the cat sera. The high prevalence of antibodies observed in the present study indicates that FCoV infections are common in southern Italian cat populations
Canine coronavirus inactivation with physical and chemical agents
No full textCanine coronavirus (CCoV) is responsible for mild or moderate enteritis in puppies. The virus is highly contagious and avoiding contact
with infected dogs and their excretions is the only way to ensure disease prevention. Since no studies have yet focused on the sensitivity
of CCoV to chemical biocides the present investigation examined the efficiency of physical and chemical methods of viral
inactivation. CCoV infectivity was stable at +56 C for up to 30 min, but tended to decrease rapidly at +65 C and +75 C. Germicidal
ultra-violet (UV–C) light exposure demonstrated no significant effects on virus inactivation for up to 3 days. CCoV was observed to be
more stable at pH 6.0–6.5 while extreme acidic conditions inactivated the virus. Two tested aldehydes inactivated the virus but their
action was temperature- and time-dependent. The methods for CCoV inactivation could be applied as animal models to study human
coronavirus infection, reducing the risk of accidental exposure of researchers to pathogens during routine laboratory procedures
High cell passaged canine coronavirus vaccine providing sterile immunity
No full textOBJECTIVES: To evaluate the ability of a high-cell-passage canine coronavirus vaccine to immunise dogs against challenge with a field isolate of the virus.
METHODS: Three dogs that had previously tested seronegative and virus-negative for canine coronavirus were inoculated twice, at 21-day intervals, with the vaccine and kept under observation. Two seronegative and virus-negative dogs served as unvaccinated controls. For safety tests, two additional dogs were inoculated oronasally with 10 times the vaccinal dose and no reactions were observed. Faecal samples were collected daily from the vaccinated dogs after the first and second inoculations. Both vaccinated and control dogs were challenged two weeks after the second vaccination with a field canine coronavirus strain. Blood samples were collected for serological tests before vaccination and at weekly intervals after vaccinations and challenge.
RESULTS: Virus was not detected in faecal samples after the first or second vaccinations by virus isolation assays and PCR. Significantly, the vaccinated dogs did not have clinical signs after challenge and no virus shedding was observed. The two unvaccinated control dogs had moderate enteritis, and virus was detected in cell cultures starting from three days postchallenge (dog 1) and two days postchallenge (dog 2), and by PCR for 23 median days.
CLINICAL SIGNIFICANCE: This study showed the efficacy of a high-cell-passage canine coronavirus vaccine in preventing infection of dogs by virulent virus and, specifically, its ability to induce sterilising immunity
Coronavirus morphology and evolution, with special emphasis on coronaviruses of carnivores
No full textThe several studies carried out by different researchers on canine coronavirus (CCoV) have focused upon the epidemiological relevance of this virus and, considering the wide diffusion of CCoV infections among dog populations, the Author underlines the need for further investigation on the biology of CCoVs and on the pathogenetic role of their infections. Genetic diversity among coronaviruses is accounted for by linear evolution as well as by a sudden, dramatic shift generated by RNA deletion or recombination events. In the last decade it has been observed that CCoV has evolved. During the monitoring of two pups naturally infected with CCoV, a long-term faecal shedding of the virus was observed and sequence analysis of the M gene fragment amplified from the faecal samples collected in the late stage of the CCoV infection, revealed a genetic drift to FCoV, which has led to the designation of these atypical CCoVs as FCoV-like CCoVs. In order to investigate more in-deeply the genetic diversity of these FCoV-like CCoVs, the attention was focused on the S gene which possesses a high degree of variation in the 5’end whereas it is more conserved in the 3’end. The analysis confirmed the existence of a new CCoV genotype in the faeces of pups with enteritis, which has been referred to as CCoV type I
VALUTAZIONE DEGLI ANTICORPI VERSO I CORONAVIRUS FELINI E CONFRONTO DI TECNICHE SIEROLOGICHE
No full textI coronavirus felini (FCoVs) sono distinti in due sierotipi, I e II, in base alle correlazioni
sierologiche con il coronavirus del cane (CCoV). Il sierotipo I è il virus originale ma cresce
con difficoltà nelle colture cellulari. FCoV II invece viene coltivato in vitro anche se è
meno diffuso rispetto al sierotipo I. FCoVs sono responsabili di infezioni subcliniche nei
gatti e le percentuali più elevate di infezione si registrano nei gattili e negli allevamenti.
Sono tuttavia virus ubiquitari e il monitoraggio sierologico permette di ottenere
informazioni attendibili sulla loro diffusione nell’ambiente. In Italia i dati sulla presenza di
FCoVs sono scarsi. Sono stati quindi raccolti 100 sieri di gatti provenienti da gattili e
ambienti domestici della Puglia e è stata valutata la presenza di anticorpi verso FCoVs I e II
mediante il test VN messo poi a confronto con i test ELISA e IFI. La ricerca di anticorpi
verso FCoV I è stata valutata solo mediante IFI, dal momento che FCoV I replica con
difficoltà in vitro, che ha svelato una sieropositività pari al 72%. Ottanta sieri risultati
positivi verso FCoV II mediante VN, sono stati confermati in ELISA. L’ELISA ha inoltre
svelato ulteriori 2 sieri positivi rispetto alla VN e ulteriori 4 sieri positivi rispetto alla IFI.
Tutti i sieri positivi in ELISA sono stati confermati con il Western blotting. In definitiva il
test ELISA si è rivelato sostanzialmente più sensibile rispetto a VN e IFI, svelando una
sieropositività verso FCoV II pari a 82%. Quando VN è stata considerata come test gold
standard, l’ELISA ha dimostrato una sensitività pari al 100% e una specificità pari al 90%,
con un agreement del 98%. Quando l’ELISA è stata confrontata con il test IFI considerato
come gold standard, la sensibilità è stata ancora 100%, la specificità 81%, con un
agreement del 96%.
L’elevata percentuale di positività verso FCoVs osservata, conferma che l’infezione da
FCoV è ampiamente diffusa nei gatti della Puglia, anche se la diffusione percentuale dei
due sierotipi è differente da quella stimata in altre aree geografiche dove prevale il sierotipo
I. Inoltre nel presente studio il test ELISA ha dimostrato una buona sensibilità e specificità
per la ricerca di anticorpi verso FCoV, così come è stato osservato nel passato per la ricerca
di anticorpi verso CCoV, e può essere considerata come test valido per lo screening
sierologico dei gatti verso FCoVs
- …
