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. 1. 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. 1. 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.

Detection of four Borrelia burgdorferi genospecies and first report of human granulocytic ehrlichiosis agent in Ixodes ricinus ticks collected in central Italy

The presence of Borrelia burgdorferi s.l. and of Ehrlichia phagocytophila group was sought by PCR in Ixodes ricinus collected in a protected area of central Italy. Nymphs (n = 1475, gathered in 295 pools of 5 nymphs each) and adult ticks (n = 28) were examined. B. burgdorferi s.l. was detected in 13.8% of the nymph pools; of these, 63.4% were infected by B. valaisiana, 26.8% by B. afzelii, 7.3% by B. garinii, and 2.5% by B. burgdorferi s.s. Only a single adult male tick proved to host B. afzelii. The agent of human granulocytic ehrlichiosis (HGE) was detected in 2.7% of the nymph pools. Two HGE agent-positive nymph pools were also found to be positive for B. garinii and for B. afzelii, respectively. This is the first report from central Italy of the finding of the HGE agent in ticks.

Isolation and Characterization of Two European Strains of Ehrlichia phagocytophila of Equine Origin

ABSTRACT We report the isolation and partial genetic characterization of two equine strains of granulocytic Ehrlichia of the genogroup Ehrlichia phagocytophila. Frozen whole-blood samples from two Swedish horses with laboratory-verified granulocytic ehrlichiosis were inoculated into HL-60 cell cultures. Granulocytic Ehrlichia was isolated and propagated from both horses. DNA extracts from the respective strains were amplified by PCR using primers directed towards the 16S rRNA gene, the groESL heat shock operon gene, and the ank gene. The amplified gene fragments were sequenced and compared to known sequences in the GenBank database. With respect to the 16S rRNA gene, the groESL gene, and the ank gene, the DNA sequences of the two equine Ehrlichia isolates were identical to sequences found in isolates from clinical cases of granulocytic ehrlichiosis in humans and domestic animals in Sweden. However, compared to amplified DNA from an American Ehrlichia strain of the E. phagocytophila genogroup, differences were found in the groESL gene and ank gene sequences.