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A Mediterranean arbovirus: the Toscana virus
No full textToscana virus (Bunyaviridae family, Phlebovirus genus) is a sandfly fever virus responsible for human neurological infections. Sandfly viruses are transmitted by insect vectors (Phlebotomus species) and the infection is present in climatic areas that allow the life cycle of the vector. The arthropode-borne Toscana virus is the etiologic agent of meningitis, meningoencephalitis, and encephalitis. The frequency of this neuropathic infection increases in the summer months, peaking in August in the endemic Mediterranean areas (Italy, Portugal, Spain, and Cyprus). Infection diagnosis is carried out by molecular assays and immunoenzymatic tests, which are rapid and sensitive. Recent studies have investigated the antigenic properties of the viral proteins (nucleoprotein N and surface glycoproteins G1 and G2), to better understand their immunogentic role
Helicobacter pylori determinants of pathogenicity
No full textThe bacterium Helicobacter pylori colonises the stomach of man and induces a strong inflammatory response. Differences in the possession of pathogenicity determinants by H. pylori isolates could account in part for the different clinical outcomes of infection. The main H. pylori pathogenic factors, i.e. urease, the cytotoxin VacA, and the genes involved in virulence contained in the pathogenicity island (PAI) cag, may promote tissue damage and ulceration, and could contribute to gastric cancer development. Strains with the mosaic vacA allelic type s1a/m1 and possessing the cag insertion are considered endowed with increased inflammatory potential, and are more likely to be isolated from patients with peptic ulcer and gastric cancer. The presence in H. pylori cag PAI of operons involved in the stimulation of gastric epithelial cells to secrete high levels of inflammatory cytokines, in mobilisation of DNA, and formation of secretory mechanisms and conjugation apparati, could contribute to increase the risk of gastric cancer development in patients infected by this microorganism
Rapid identification of Toscana virus by nested PCR during an outbreak in the Siena area of Italy
No full textThe sand fly-transmitted Toscana virus is recognized as an etiologic agent of an aseptic meningitis with a long convalescence. This infection has been reported overall in many tourists or in a seronegative population circulating in endemic Mediterranean areas (Italy, Portugal, Egypt, and Cyprus). We report a cluster of acute Toscana virus infections in the local population during the summer of 1995. Twenty-one clinical cases of meningitis were investigated for the presence of Toscana virus by nested PCR performed on the S segment of the virus RNA extracted from cerebrospinal fluid samples
Neutralization of Toscana virus is partially mediated by antibodies to the nucleocapsid protein
No full textThe envelope glycoproteins G1/G2 of Toscana virus (TOSV) seem to have the most important protective role in stimulating antibodies against the disease in humans, as well as antibodies against the Nucleoprotein (N), a partial neutralizing activity. Mice immunized with TOSV recombinant Nucleoprotein developed a strong humoral response to the TOSV that revealed the presence of neutralizing antibody than in vitro assay. The neutralizing antibody titre of mice immunized with the whole TOSV was analyzed before and after absorption of the sera with the recombinant N protein. A decrease of the neutralizing activity was observed in the treated sera. Similar results were obtained absorbing human anti-TOSV positive sera with the recombinant N protein. This study was designed to identify the nature of antibodies produced against the N protein of TOSV in mice and to establish correlation with antibodies produced in humans by natural infection. (C) 2001 Wiley-Liss, Inc
Outbreak and persistence of Chlamydia pneumoniae infection in a Italian family
No full textWe describe an outbreak of familial infection of Chlamydia pneumoniae, an etiological agent for respiratory tract infections. In a family member detection of C. pneumoniae on a pharyngeal swab by polymerase chain reaction was positive until four months after the onset of symptoms, despite a course of antibiotics known to be effective against Chlamydia specie
Comparison of M-MLV reverse transcriptase and Tth polymerase activity in RT-PCR of samples with low virus burden
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