Vittorio Larocca

Enteric disease in dogs naturally infected by a novel canine astrovirus.

ABSTRACT Infection by a novel canine astrovirus was associated with gastroenteritis in two dogs. The virus displayed 70.3 to 73.9% amino acid identity to other canine astroviruses in the full-length capsid. Specific antibodies were detected in the convalescent-phase sera of the dogs, indicating seroconversion. Also, the virus appeared weakly related antigenically to the prototype canine astrovirus isolate ITA/2008/Bari.

Persistent infection caused by Hobi-like pestivirus

ABSTRACT A calf persistently infected by Hobi-like pestivirus was monitored for about 6 months, displaying clinical signs typical of bovine viral diarrhea virus persistent infection and shedding the virus through all body secretions, with maximal titers detected in urine. This report provides new insights into the pathogenesis of the emerging pestivirus.

Astroviruses in rabbits.

A novel astrovirus was found more frequently in rabbits with enteric disease than in asymptomatic animals.

Mucosal disease-like syndrome in a calf persistently infected by Hobi-like pestivirus

ABSTRACT A calf persistently infected with Hobi-like pestivirus displayed severe clinical signs and subsequently died. Gross lesions and histopathological changes were suggestive of hemorrhagic and necrotic inflammation involving several tissues. A Hobi-like pestivirus pair was isolated from the dead calf, i.e., cytopathogenic (CP) and noncytopathogenic (NCP) strains strictly related to each other and to Italian prototype isolates at the genetic level. Two biotype-specific real-time reverse transcription-PCR assays determined the time of the emergence of the CP virus as 1 month before the calfs death. This highest RNA titers were reached in lymphoid and nervous system tissues, whereas only traces of CP viral RNA were found in blood. In contrast, great NCP virus loads were present in all tissues and biological fluids. The present report provides new insights into the pathogenesis and molecular mechanisms of this emerging group of pestiviruses.

Comparison of the cross-antibody response induced in sheep by inactivated bovine viral diarrhoea virus 1 and Hobi-like pestivirus.

Hobi-like pestivirus, a new tentative species within genus Pestivirus, was firstly detected in foetal bovine serum batches and later associated to respiratory distress and reproductive failures in cattle. In the present study, the cross-antibody response between bovine viral diarrhoea virus 1 (BVDV-1) and the emerging pestivirus was evaluated in the sheep model. Ten sheep were immunised against BVDV-1 or Hobi-like pestivirus using inactivated preparations and the induced antibody responses were evaluated against the homologous and heterologous viruses. The results showed that heterologous antibody titres were significantly lower than the homologous ones, thus suggesting the need to develop specific vaccines against the emerging pestiviral species.

Clinical Bovine Piroplasmosis Caused by Babesia occultans in Italy

ABSTRACT A clinical outbreak of bovine piroplasmosis was reported in Italy. The etiological agent was characterized as Babesia occultans, a parasite regarded as apathogenic and never detected before in continental Europe. This report paves the way for further studies to assess the occurrence of this tick-transmitted protozoan in other European regions.

A duplex real-time PCR assay based on TaqMan technology for simultaneous detection and differentiation of canine adenovirus types 1 and 2

Canine adenoviruses are a major cause of disease in dogs, coyotes, red foxes and wolves, as well as in other carnivores and marine mammals. Canine adenovirus type 1 (CAdV-1) and canine adenovirus type 2 (CAdV-2) cause infectious canine hepatitis (ICH) and infectious tracheobronchitis (ITB), respectively. In this study, a duplex real-time PCR assay for simultaneous detection and characterisation of CAdV-1 and CAdV-2 was developed by using a single primer pair and virus-specific probes. The assay was validated testing standard DNAs produced on purpose and clinical samples of various matrices known to be positive for CAdV-1, CAdV-2 or both viruses. Precise calculation of DNA loads in samples containing a wide range of viral amounts was allowed by generating a standard curve for absolute quantification. The assay was proven to be highly specific, since no cross-reactions with the different CAdV type was observed, and sensitive, being able to detect less than 10 copies of CAdV-1/CAdV-2 DNA. The low intra-assay and interassay coefficient of variations demonstrated a high repeatability, thus confirming the potential use of this assay for quantitative detection of CAdV-1 and CAdV-2 for rapid diagnosis and epidemiological investigations.

Molecular surveillance of traditional and emerging pathogens associated with canine infectious respiratory disease

Abstract A molecular survey for traditional and emerging pathogens associated with canine infectious respiratory disease (CIRD) was conducted in Italy between 2011 and 2013 on a total of 138 dogs, including 78 early acute clinically ill CIRD animals, 22 non-clinical but exposed to clinically ill CIRD dogs and 38 CIRD convalescent dogs. The results showed that canine parainfluenza virus (CPIV) was the most commonly detected CIRD pathogen, followed by canine respiratory coronavirus (CRCoV), Bordetella bronchiseptica, Mycoplasma cynos, Mycoplasma canis and canine pneumovirus (CnPnV). Some classical CIRD agents, such as canine adenoviruses, canine distemper virus and canid herpesvirus 1, were not detected at all, as were not other emerging respiratory viruses (canine influenza virus, canine hepacivirus) and bacteria (Streptococcus equi subsp. zooepidemicus). Most severe forms of respiratory disease were observed in the presence of CPIV, CRCoV and M. cynos alone or in combination with other pathogens, whereas single CnPnV or M. canis infections were detected in dogs with no or very mild respiratory signs. Interestingly, only the association of M. cynos (alone or in combination with either CRCoV or M. canis) with severe clinical forms was statistically significant. The study, while confirming CPIV as the main responsible for CIRD occurrence, highlights the increasing role of recently discovered viruses, such as CRCoV and CnPnV, for which effective vaccines are not available in the market.

Detection and Full-Length Genome Characterization of Novel Canine Vesiviruses

Vesiviruses have been detected in several animal species and as accidental contaminants of cells. We detected vesiviruses in asymptomatic kennel dogs (64.8%) and symptomatic (1.1%) and asymptomatic (3.5%) household dogs in Italy. The full-length genome of 1 strain, Bari/212/07/ITA, shared 89%–90% nt identity with vesiviruses previously detected in contaminated cells.

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

Abstract 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.