ANTIGENIC AND GENOMIC ANALYSIS OF A BORRELIA-BURGDORFERI SENSU-STRICTO STRAIN ISOLATED FROM IXODES-RICINUS TICKS IN ALTO ADIGE-SOUTH TYROL,ITALY

A Borrelia burgdorferi sensu late strain isolated from Ixodes ricinus ticks in Alto Adige-South Tyrol (Northern Italy) was analyzed by sodiu m dodecyl sulfate-polyacrylamide gel electrophoresis (SDS-PAGE) of who le cell proteins, Western immunoblotting analysis (WBA) with polyclona l and monoclonal antibodies, and pulsed-field gel electrophoresis (PFG E). The isolate named BZ6 was identified as belonging to the genospeci es B. burgdorferi sensu stricto on the basis of its protein profile an d its reactivity with monoclonal and polyclonal antibodies. The PFGE s tudy performed with the two rare-cutting restriction enzymes MluI and SmaI confirmed the SDS-PAGE and WBA characterizations, but showed a ge netic diversity between the isolate and two out of the three B. burgdo rferi sensu stricto strains used in this study as controls, the Americ an type strain B31 and the locally isolated strain BZ1. No difference in the PFGE patterns between the isolate BZ6 and the Swiss strain IRS was noted. Our findings show the value of PFGE analysis for classifyin g B. burgdorferi sensu late isolates and for revealing their genetic d iversity, and its usefulness for epidemiological investigations.