Molecular detection and characterization of spotted fever group rickettsiae in ticks from Central Italy

- Rickettsial pathogens were investigated by PCR in ticks from Central Italy.
- Minimum infection rate of ticks by SFG rickettsiae was 12.4%.
- R. aeschlimannii, R. monacensis, R. massiliae and R. conorii were detected.
- Circulation of pathogenic rickettsiae in Central Italy was confirmed.
- This is the first report of R. massiliae in Latium region.

The aim of this study was to investigate the presence of rickettsial pathogens in ticks from Central Italy. A total of 113 ticks hailed from Latium and Tuscany regions were identified and tested by PCR to detect gltA, ompA, ompB genes of Rickettsia. Positive amplicons were sequenced and identified at species level. Ticks were analyzed individually or in pools. The percentage of positivity for SFG rickettsiae was 12.4%, expressed as minimum infection rate (MIR) assuming that one tick was positive in each positive pool. Rickettsia aeschlimannii was detected in Hyalomma marginatum, Rickettsia monacensis in Ixodes ricinus and Rickettsia massiliae and Rickettsia conorii in Rhipicephalus sanguineus sensu lato. These findings confirm the circulation of pathogenic rickettsiae in Latium and Tuscany regions. To our knowledge this is the first report of R. massiliae in Latium region.