Ilaria Duprè

Antibacterial activity of ozonized sunflower oil (OLEOZON)

L.A. SECHI, I. LEZCANO, N. NUNEZ, M. ESPIM, I. DUPRÈ, A. PINNA, P. MOLICOTTI, G. FADDA AND S. ZANETTI. 2001.

Distribution of Vibrio cholerae virulence genes among different Vibrio species isolated in Sardinia, Italy

The members of the genus Vibrio include harmless aquatic strains as well as strains capable of causing epidemics of cholera. Diarrhoea caused by Vibrio cholerae is attributed to cholerae enterotoxin (CT) codified by the ctx operon and regulated by a number of virulence genes such as toxT, toxR and toxS. Fifty‐two Vibrio strains were isolated from different aquatic environments in and around Sardinia and searched by PCR for the presence of ctxA, zot, ace, toxR, toxS, toxT, tcpA and vpi virulence genes in the genomes of the isolates. The toxR operon was found in 27 Vibrio alginolyticus strains out of 42 analysed, in three out of four V. cholerae non‐O1 strains and in three Vibrio parahaemolyticus isolates. A positive amplification for the virulence pathogenic island (vpi) was produced by five V. alginolyticus strains. Finally, the ace expected amplification fragment was found in two V. alginolyticus isolates whereas the amplification with zot primers produced the expected fragment in one V. alginolyticus isolate. Differentiation of these strains with a PCR fingerprinting technique revealed no association between the presence of virulence genes and a particular fingerprinting pattern. Although most Vibrio species are considered non‐pathogenic or only potentially harmful to humans, the finding of V. cholerae virulence genes in other members of the genus Vibrio, and the recent reports of the creation and evolution of pandemic strains of V. cholerae, may give a new perspective to the significance of these results.

Genotypic changes in DNA fingerprinting patterns of Mycobacterium tuberculosis strains from HIV-positive persons in Sardinia

Amongst infectious diseases, tuberculosis is still the major killer in the world. In some developing countries tuberculosis infection has reached epidemic proportions and is increasing worldwide. This rapid growth is thought to be correlated in part to the movement of people from developing countries, where tuberculosis largely occurs, to industrialized countries. It is also due in part to AIDS, as Mycobacterium tuberculosis infection appears to be one of the first indications of a loss of immune system function, and those infected are susceptible to a number of opportunistic infections, including infections by other mycobacteria, and finally because the expectation of life is increased. In the present study, we applied a computer-assisted method to analyse DNA fingerprints and construct dendrograms of M. tuberculosis strains isolated from HIV-positive patients.