Luigi Morganti

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.

TaqMan Based Real Time PCR for the Quantification of Canine Distemper Virus

Scagliarini, A., Dal Pozzo, F., Gallina, L., Vaccari, F. and Morganti, L., 2007. TaqMan based real time PCR for the quantification of canine distemper virus. Veterinary Research Communications, 31(Suppl. 1), 261–263

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.

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.

Co-infection with multiple variants of canine parvovirus type 2 (CPV-2).

Battilani, M., Gallina, L., Vaccari, F. and Morganti, L., 2007. Co-infection with multiple variants of canine parvovirus type 2 (CPV-2). Veterinary Research Communications, 31(Suppl. 1), 209–212

Analysis of the N protein in feline coronavirus strains in Italy.

infection but also cause a progressive, fatal immune-mediated disease, feline infectious peritonitis (FIP). The structural proteins of FCoVs include the spike (S), the membrane (M), and, the most representative, the nucleocapsid protein (N). Coronavirus N proteins vary from 377 to 455 amino acids in length, are highly basic, have a high serine content (7–11%), and are potential targets for phosphorylation. Antigenic studies have shown that the N protein is one of the immunodominant antigens in the CoV family. The cellular immune response against the N protein of some animal coronaviruses can enhance recovery from the virus infection. Immunization with a cell lysate using a recombinant baculovirus-expressing feline infectious peritonitis virus (FIPV) nucleocapsid protein was effective in preventing the progression of FIP. To investigate the antigenic role of the N protein, we carried out a computational analysis of the N protein of FCoV strains detected in healthy and diseased cats on the basis of the primary amino acid sequences.