Apyrase, the product of the virulence plasmid-encoded phoN2 (apy) gene of Shigella flexneri, is necessary for proper unipolar IcsA localization and for efficient intercellular spread.

The role in virulence of the Shigella flexneri ospB-phoN2 operon has been evaluated. Here we confirm that OspB is an effector and show that apyrase, the product of phoN2, may be a virulence factor, since it is required for efficient intercellular spreading. Apyrase may be important in a deoxynucleoside triphosphate-hydrolyzing activity-independent manner, suggesting that it may act as an interaction partner in the process of IcsA localization.

Prevalence of Borrelia Burgdorferi sensu lato genomospecies and of the human granulocytic ehrlichiosis (HGE) agent in Ixodes ricinus ticks collected in the area of Monti Lepini, Italy.

Ticks are obligate hematophagous arthropods that are parasites in every class of vertebrates in most regions of the world. They are also considered to be important vectors for the transmission of human infectious diseases. In the present study we used polymer chain reaction (PCR) amplification analysis to determine the prevalence of Borrelia burgdorferi and Ehrlichia phagocytophila, the agents of, respectively, Lyme borreliosis and human granulocytic ehrlichiosis, among ticks inhabiting the area of Monti Lepini, a wild area located in the Latium Region of Italy. A total of 141 I. ricinus ticks (125 nymphs and 16 adults) were collected in the studied area. Total DNAs were extracted from I. ricinus nymphs (pooled in groups of five) and from individual adults. The DNA samples were examined for the presence of B. burgdorferi sensu lato and E. phagocytophila by PCR using two specific pairs of oligonucleotides that specifically amplify distinct DNA regions of the 16S rRNA genes of the two species. The prevalence of vectors infected with B. burgdorferi s. l. was 16% in pooled nymphs samples, and 12.5% in adult ticks, while E. phagocytophila was found only in pooled nymphs samples (8%). Three genomospecies were identified, namely Borrelia afzelii, Borrelia garinii, and Borrelia valaisiana, in samples found positive for B. burgdorferi s. l. No sample was found positive for Borrelia burgdorferi sensu stricto.

Prevalence of IgG antibodies against Borrelia Burgdorferi s.l. and Ehrlichia Phagocytophila in sera of patients presenting symptoms of Lyme disease in a central region of Italy.

The aim of this study was to evaluate the prevalence (seroprevalence) of antibodies against Borrelia burgdorferi and Ehrlichia phagocytophila among patients resident in Lazio, a region of central Italy. Of a sample of 1,050 patients, which presented clinical manifestations related to Lyme disease, 34 (3.2%) were Borrelia-seropositive (Lyme index value >/= 1.2). The sera of 25 out of the 34 patients that were Borrelia-positive were also analysed for the presence of antibodies against E. phagocytophila and 3 (12%) were found Ehrlichia-positive (titres >1:64). No Ehrlichia positive samples were found among sera of 250 Borrelia-negative patients. Since both B. burgdorferi s.l. and Ehrlichia species share the same tick vector (Ixodes ricinus), our results indicate that concurrent transmission of these microbial pathogens might have been occurred among the patients included in this study.