Mara Battilani

Analysis of canine parvovirus sequences from wolves and dogs isolated in Italy

The VP2 genes of Italian canine parvovirus (CPV) type 2 strains isolated from dogs and wolves were sequenced and a three-dimensional model of the VP2 capsid protein was constructed. Two mutations were detected in the VP2 sequences of the Italian strains: one at residue 297 and one at residue 265. Variant 297 is the predominant CPV isolate in Europe, whereas variant 265 has never been detected before. The mutation at residue 265 causes a disruption in a G strand of the beta-barrel in the VP2 protein. Data on strains isolated from wolves demonstrated that the same strain of CPV can circulate among domestic and wild canids; therefore, this result leads us to exclude the possibility that a separate parvovirus pool exists in wild populations.

Genetic analysis of canine parvovirus isolates (CPV-2) from dogs in Italy.

Genetic and antigenic properties of 62 field isolates of canine parvovirus (CPV-2) collected from 1994 to 2001 in Italy were investigated. Antigenic characterisation was conducted using specific monoclonal antibodies (Mabs). The VP1\VP2 gene was amplified by PCR and characterised with restriction endonucleases to detect the 297 and 265 variant. The VP2 gene of 16 isolates was sequenced and molecular genetic analysis was conducted. The antigenic type prevalent among our isolates is type 2a as well as the 297 variant, which is also prevalent in the rest of Europe. Only the 9.7% of the isolates have the T265P mutation. The VP2 sequences of CPV-2 isolates were very similar to recent Asian isolates. In the threefold spike of CPV-699 a coding change was detected in the 440 residue where threonine was substituted by alanine: the same mutation has been found in two Asian CPV-2 isolates from leopard cats [Virology 278 (2000) 13]. Phylogenetic analysis revealed that the Italian CPV-2 strains followed the same evolution as observed in other countries and they gave no indication of a separate lineage.

Genetic complexity and multiple infections with more Parvovirus species in naturally infected cats

Parvoviruses of carnivores include three closely related autonomous parvoviruses: canine parvovirus (CPV), feline panleukopenia virus (FPV) and mink enteritis virus (MEV). These viruses cause a variety of serious diseases, especially in young patients, since they have a remarkable predilection for replication in rapidly dividing cells. FPV is not the only parvovirus species which infects cats; in addition to MEV, the new variants of canine parvovirus, CPV-2a, 2b and 2c have also penetrated the feline host-range, and they are able to infect and replicate in cats, causing diseases indistinguishable from feline panleukopenia. Furthermore, as cats are susceptible to both CPV-2 and FPV viruses, superinfection and co-infection with multiple parvovirus strains may occur, potentially facilitating recombination and high genetic heterogeneity. In the light of the importance of cats as a potential source of genetic diversity for parvoviruses and, since feline panleukopenia virus has re-emerged as a major cause of mortality in felines, the present study has explored the molecular characteristics of parvovirus strains circulating in cat populations. The most significant findings reported in this study were (a) the detection of mixed infection FPV/CPV with the presence of one parvovirus variant which is a true intermediate between FPV/CPV and (b) the quasispecies cloud size of one CPV sample variant 2c. In conclusion, this study provides new important results about the evolutionary dynamics of CPV infections in cats, showing that CPV has presumably started a new process of readaptation in feline hosts.

Quasispecies composition and phylogenetic analysis of feline coronaviruses (FCoVs) in naturally infected cats

Abstract Quasispecies composition and tissue distribution of feline coronaviruses (FCoVs) were studied in naturally infected cats. The genomic complexity of FCoVs was investigated using single-strand conformational polymorphism (SSCP) analysis of N and ORF7b amplicons, and the evolutionary process was investigated by sequence-based phylogenetic analysis. SSCP analysis showed high heterogeneity of the FCoV genome which was correlated with the seriousness of the clinical form. The two genomic regions analysed showed different levels of variation; the N region demonstrated significant heterogeneity as compared to ORF7b. Phylogenetic analysis of the nucleotide sequences showed the clear separation of sequences analysed on the basis of virulence and geographical origin. A maximum likelihood analysis of N and ORF7b data sets showed a situation of strong heterogeneity for the N region.

Serum α1-acid glycoprotein (AGP) concentration in non-symptomatic cats with feline coronavirus (FCoV) infection

Previous studies have demonstrated that the concentration of α1-acid glycoprotein (AGP) transiently increases in asymptomatic cats infected with feline coronavirus (FCoV). In order to establish whether these fluctuations depend on the FCoV status, the serum concentration of AGP and anti-FCoV antibody titres and/or faecal shedding of FCoVs in clinically healthy cats from catteries with different levels of prevalence of FCoV infection were monitored over time. Serum AGP concentrations fluctuated over time in clinically healthy cats from the cattery with the highest prevalence of feline infectious peritonitis (FIP) and significantly increased just before an outbreak of FIP. Further studies are required to clarify whether the observed increase of AGP concentration is a consequence of the increased viral burden or a protective response against mutated viral strains. Nevertheless, the results of the present study suggest that AGP might be useful in monitoring FCoV–host interactions in FCoV-endemic catteries.

Analysis of the Evolution of Feline Parvovirus (FPV)

Feline panleukopenia is a viral disease known since the beginning of the 20th century that occurs in cats, causing severe leukopenia, gastro-enteritis and nervous signs (Verge and Christoforoni, 1928). Feline panleukopenia is caused by feline panleukopenia virus (FPV), a DNA virus belong to the family Parvoviridae, genus Parvovirus, subgroup of feline parvovirus: FPV is the representative virus inside the group. The new antigenic variants of CPV-2, type 2a and type 2b have gained the feline host range and can infect, replicate and cause disease in cats with clinical signs similar to feline panleukopenia (Truyen et al., 1996a). In Japan and the United States (Mochizuchi et al., 1996; Truyen et al., 1996b) the proportion of CPV-like viruses from domestic cats was found to be 10%. Furthermore, in Africa CPV-2 was isolated from a wild felid (Steinel et al., 2000) and in Vietnam and Taiwan CPV-2 was detected in wild and domestic cats (Ikeda et al., 1999; Ikeda et al., 2000). In some Asian countries, more than 80% of the isolates were of the canine parvovirus (CPV) type, suggesting that CPV type 2a or 2b can spread in cats more easily than conventional FPV (Ikeda et al., 2000). In this study, we performed a molecular study on feline parvovirus strains isolated from domestic cats to investigate which parvoviruses strains are spread in the feline population and to monitor the evolution of FPV in Italy.

Association between faecal shedding of feline coronavirus and serum α1-acid glycoprotein sialylation

The sialylation pattern of serum α1-acid glycoprotein (AGP) in non-symptomatic cats infected by feline coronavirus (FCoV) and its possible relationship with the amount of FCoVs shed in faeces were investigated. Blood from three specific pathogen-free cats (group A) and from 10 non-symptomatic FCoV-positive cats from catteries with low (group B, three cats) or high (group C, seven cats) levels of faecal shedding were collected monthly. AGP was purified from serum and Western blotting followed by lectin-staining of α(2,3)-linked and α(2,6)-linked sialic acid. Faecal shedding was quantified in group C by quantitative polymerase chain reaction. Variations of AGP sialylation were recorded only in cats from group C, on which viral shedding peaked before the occurrence of feline infectious peritonitis (FIP) in the cattery, and decreased 1 month later, when serum AGP had an increase of α(2,3)-linked sialic acid. These results suggest that hypersialylation of AGP may be involved in host–virus interactions.

Molecular Analysis of the NP Gene of Italian CDV Isolates

Canine distemper virus (CDV) is a highly contagious pathogen that occurs worldwide, causing a fatal disease in young carnivores. This virus is a member of the genus Morbillivirus in the family Paramixoviridae. The disease has been controlled throughout the world using live attenuated vaccines, but in the last few years an increasing number of distemper cases in vaccinated dogs has been recorded in Italy as well as in other European countries. (Blixenkrone-Moller et al., 1993). Epidemiological, serological and histopatological research suggested that the ‘new CDVs’ had altered antigenicities and/or different pathogenicities from the old strains (Yoshida et al. 1998). Infections caused by these new viruses may explain the increase of distemper cases in Italy. Analysis of the nucleocapsid protein (NP) gene of wildtype strains indicated a separate cluster from the vaccine strain (Yoshida et al., 1998). The NP protein is the most abundant viral structural protein and has been was demonstrated to influence viral persistence as well as regulatory functions such as transcription and replication (Stettler and Zurbriggen, 1995). In this study we analysed a partial nucleotide sequence of the NP gene of four wildtype CDV strains isolated in Italy.

Genetic diversity and molecular epidemiology of Anaplasma

Anaplasma are obligate intracellular bacteria of cells of haematopoietic origin and are aetiological agents of tick-borne diseases of both veterinary and medical interest common in both tropical and temperate regions. The recent disclosure of their zoonotic potential has greatly increased interest in the study of these bacteria, leading to the recent reorganisation of Rickettsia taxonomy and to the possible discovery of new species belonging to the genus Anaplasma. This review is particularly focused on the common and unique characteristics of Anaplasma marginale and Anaplasma phagocytophilum, with an emphasis on genetic diversity and evolution, and the main distinguishing features of the diseases caused by the different Anaplasma spp. are described as well.

Isolation and Genetic Characterization of Betanodavirus from Wild Marine Fish from the Adriatic Sea

Ciulli, S., Galletti, E., Grodzki, M., Alessi, A., Battilani, M. and Prosperi, S., 2007. Isolation and genetic characterization of Betanodavirus from wild marine fish from the Adriatic Sea. Veterinary Research Communications, 31(Suppl. 1), 221–224