In Vitro Antiviral and Virucidal Activity of Ozone against Feline Calicivirus.

The Caliciviridae family includes several viral pathogens of humans and animals, including norovirus (NoV), genus Norovirus, and feline calicivirus (FCV), genus Vesivirus. Due to their resistance in the environment, NoV and FCV may give rise to nosocomial infections, and indirect transmission plays a major role in their diffusion in susceptible populations. A pillar of the control of viruses resistant to an environment is the adoption of prophylaR1.6ctic measures, including disinfection. Since NoVs are not cultivatable in common cell cultures, FCV has been largely used as a surrogate of NoV for the assessment of effective disinfectants. Ozone (O3), a molecule with strong oxidizing properties, has shown strong microbicidal activity on bacteria, fungi, protozoa, and viruses. In this study, the virucidal and antiviral activities of an O3/O2 gas mixture containing O3 were tested at different concentrations (20, 35, and 50 µg/mL) for distinct contact times against FCV. The O3/O2 gas mixture showed virucidal and antiviral activities against FCV in a dose- and contact time-dependent fashion. Ozonation could be considered as a valid strategy for the disinfection of environments at risk of contamination by FCV and NoV.

Virucidal Activity of Lemon Essential Oil against Feline Calicivirus Used as Surrogate for Norovirus.

Norovirus (NoV) is regarded as a common cause of acute gastrointestinal illness worldwide in all age groups, with substantial morbidity across health care and community settings. The lack of in vitro cell culture systems for human NoV has prompted the use of cultivatable caliciviruses (such as feline calicivirus, FCV, or murine NoV) as surrogates for in vitro evaluation of antivirals. Essential oils (EOs) may represent a valid tool to counteract viral infections, particularly as food preservatives. In the present study, the virucidal efficacy of lemon EO (LEO) against FCV was assessed in vitro. The gas chromatography hyphenated with mass spectrometry (GC/MS) technique was used to reveal the chemical composition of LEO. The following small molecules were detected as major components of LEO: limonene (53%), ß-pinene (14.5%), γ-terpinene (5.9%), citral (3.8%), α-pinene (2.4%), and ß-thujene (1.94%). LEO at 302.0 µg/mL, exceeding the maximum non cytotoxic limit, significantly decreased viral titre of 0.75 log10 TCID50/50 µL after 8 h. Moreover, virucidal activity was tested using LEO at 3020.00 µg/mL, determining a reduction of viral titre as high as 1.25 log10 TCID50/50 µL after 8 h of time contact. These results open up perspectives for the development of alternative prophylaxis approaches for the control of NoV infection.

Detection of Selected Canine Viruses in Nigerian Free-Ranging Dogs Traded for Meat Consumption.

Animal trade favors the spreading of emerging and re-emerging pathogens. Concerns have been previously expressed regarding the risks of dog trade in spreading zoonotic pathogens in Nigeria. However, the role of these dogs in disseminating highly pathogenic canine viruses has not yet been explored. The present study aimed to identify selected canine viruses in dogs traded for meat consumption in Nigeria. A total of 100 blood samples were screened for carnivore protoparvovirus-1 (CPPV-1), canine adenovirus 1/2 (CAdV-1/2), canine circovirus (CaCV), and canine distemper virus (CDV) by using real-time PCR and conventional PCR and/or sequencing. CPPV-1 DNA was identified in 83% of canine samples while CaCV DNA and CDV RNA were detected in 14% and 17% of the dog samples, respectively. None of the dogs tested positive for CAdV-1/2. The CaCVs identified in this study clustered along with other European, Asian, and American strains. Moreover, CDV strains identified in Nigeria clustered in a separate lineage with the closest genetic relatedness to the Europe-South America-1 clade. Further surveys prior to and after arrival of dogs at the slaughtering points are required to clarify the real virus burden in these animals.

Identification and genetic characterization of equine hepaciviruses in Italy.

Viruses similar to human hepatitis C virus, hepaciviruses, have been identified in various animal species. Equine hepacivirus (EqHV) is the closest relative of human hepaciviruses. Although detected worldwide, information on EqHV epidemiology, genetic diversity and pathogenicity is still limited. In this study we investigated the prevalence and genetic diversity of EqHV in Italian equids. The RNA of EqHV was detected in 91/1932 sera (4.7%) whilst it was not detectable in 134 donkey sera screened by a TaqMan-based quantitative assay. Upon sequencing and phylogenetic analysis of genomic portions located in the NS5B, 5'UTR and NS3 genes, the Italian EqHV strains segregated into two distinct clades that are also co-circulating globally, without apparent geographic restrictions.

Caprine herpesvirus 1 (CpHV-1) vaginal infection of goats: clinical efficacy of fig latex.

The latex of Ficus carica Linn. (Moraceae) has been shown to interfere with the replication of caprine herpesvirus (CpHV)-1 in vitro. The present study was undertaken to determine the efficacy of vaginal administration of fig latex in goats experimentally infected with CpHV-1. The fig latex reduced the clinical signs of the herpetic disease although it slightly influenced the titres of CpHV-1 shed. Thus, the fig latex maintained a partial efficacy in vivo.

Multiplex real-time RT-PCR assay for bovine viral diarrhea virus type 1, type 2 and HoBi-like pestivirus.

HoBi-like pestiviruses are emerging pestiviruses that infect cattle causing clinical forms overlapping to those induced by bovine viral diarrhea virus (BVDV) 1 and 2. As a consequence of their widespread distribution reported in recent years, molecular tools for rapid discrimination among pestiviruses infecting cattle are needed. The aim of the present study was to develop a multiplex real-time RT-PCR assay, based on the TaqMan technology, for the rapid and unambiguous characterisation of all bovine pestiviruses, including the emerging HoBi-like strains. The assay was found to be sensitive, specific and repeatable, ensuring detection of as few as 10(0)-10(1) viral RNA copies. No cross-reactions between different pestiviral species were observed even in samples artificially contaminated with more than one pestivirus. Analysis of field samples tested positive for BVDV-1, BVDV-2 or HoBi-like virus by a nested PCR protocol revealed that the developed TaqMan assay had equal or higher sensitivity and was able to discriminate correctly the viral species in all tested samples, whereas a real-time RT-PCR assay previously developed for HoBi-like pestivirus detection showed cross-reactivity with few high-titre BVDV-2 samples.

HoBi-like pestivirus experimental infection in pregnant ewes: Reproductive disorders and generation of persistently infected lambs.

In order to evaluate sheep as experimental model to test the efficacy of HoBi-like pestivirus vaccines for cattle, 10 sheep at different stages of pregnancy (30 or 50 days) were experimentally infected with the Italian prototype isolate Italy-1/10-1. Irrespective of the stage of pregnancy, virus inoculation resulted in reproductive failures, consisting of abortion, stillbirths or birth of weak or persistently infected (PI) lambs. Aborted fetuses, stillborn and dead lambs displayed extensive histopathological changes, consisting of hemorrhages, congestion and mononuclear infiltration in major organs. Pestiviral antigens were detected by immunohistochemistry in most tissues with remarkable signals in lungs and kidneys. PI lambs were constantly viremic, shed the virus through the nasal secretions and feces and, in all cases but one, did not have detectable HoBi-like pestivirus antibodies before the assumption of colostrum. The single seropositive infected lamb showed low-titer viremia and viral shedding that ceased only several weeks after the 3-month observation period. The study proves that sheep are susceptible to the reproduction failures caused by HoBi-like pestivirus infection and can serve as a suitable model for the evaluation of the fetal protection induced by homologous experimental vaccines.