IDENTIFICATION OF 4 GENOMIC GROUPS OF BORRELIA-BURGDORFERI SENSU-LATOIN IXODES-RICINUS TICKS COLLECTED IN A LYME BORRELIOSIS ENDEMIC REGION OF NORTHERN CROATIA

We investigated the presence of Borrelia burgdorferi sensu late in Ixo des ricinus ticks collected in a Lyme borreliosis (LB) endemic region of northern Croatia. Ticks (n = 124) were collected at five locations and analysed by the polymerase chain reaction (PCR). A DNA fragment fr om the internal transcribed spacer (TS2) of I. ricinus was detected in all tick lysates, indicating that PCR inhibitors were not present. Bo rrelia burgdorferi sensu late DNA was detected in 56 out of 124 ticks (45%). Four genomic groups were identified: Borrelia afzelii (n = 26), Borrelia garinii (n = 5), group VS116 (n = 5) and B. burgdorferi sens u stricto (n = 1). Mixed infections of B. afzelii with group VS116 (n = 10) and B. afzelii with B. burgdorferi sensu stricto (n = 1) were al so detected. Eight ticks contained B. burgdorferi sensu lato, which co uld not be typed. The detection of B. afzelii and B. garinii in ticks was in agreement with manifestations of LB found locally. The occurren ce of group VS116 in northern Croatia and in an earlier study in The N etherlands, infers that this genomic group may be well established in European I. ricinus.