Presence and distribution of Borrelia burgdorferi sensu lato species in internal organs and skin of naturally infected symptomatic and asymptomatic dogs, as detected by polymerase chain reaction.

Tissues from Dutch family dogs symptomatic for borreliosis according to established criteria and from infected but asymptomatic dogs were tested for Borrelia burgdorferi sensu lato DNA using a polymerase chain reaction. Subsequently, B. burgdorferi sensu stricto, B. garinii, B. afzelii, and B. valaisiana were identified by hybridization. Symptomatic dogs showed a higher prevalence of Borrelia in liver samples (9 of 15) than asymptomatic dogs (9 of 43) p = 0.0049. Overall, B. garinii was the most prevalent species and occurred together with up to three other species in on liver sample. B. burgdorferi sensu stricto however, was predominantly detected in samples of synovial membranes, skin, cerebrospinal fluid, bladder, heart, and bone marrow. Nine out of 10 symptomatic dogs with a very high antibody titre were positive for Borrelia DNA by PCR in one or more of these tissues. We conclude that dissemination in naturally infected European dogs occurs and that the two most prevalent species, B. burgdorferi sensu stricto and B. garinii, differ in their tropism.

Rate of infection of Ixodes ricinus ticks with Borrelia burgdorferi sensu stricto, Borrelia garinii, Borrelia afzelii and group VS116 in an endemic focus of Lyme disease in Italy.

A study to evaluate the natural rate of infection of Ixodes ricinus with Borrelia burgdorferi sensu lato was carried out in an endemic focus of Lyme disease in the Trieste area in northern Italy. Two-hundred and twenty-seven ticks collected in ten different stations were tested individually for the presence of the spirochetes using polymerase chain reaction techniques able to identify both Borrelia burgdorferi sensu lato and the four genospecies (Borrelia burgdorferi sensu stricto, Borrelia garinii. Borrelia afzelii and group VS116). Multiple infection of individual ticks was found. The infection rate ranged from 0-70%. Infection of Ixodes ricinus with Borrelia burgdorferi group VS116 was found for the first time in Italy in both a high and a low endemic focus of Lyme disease.

Detection of four species of Borrelia burgdorferi sensu lato in Ixodes ricinus ticks collected from roe deer (Capreolus capreolus) in The Netherlands.

Roe deer (Capreolus capreolus) were investigated for their value as sentinel animals for Lyme borreliosis in the Netherlands. Serum was obtained from 114 roe deer, and 513 Ixodes ricinus, predominantly females (72%), were obtained from 47 animals (41%). The polymerase chain reaction was used to detect DNA of Borrelia burgdorferi sensu lato in a total of 190 ticks, comprising 106 engorged ticks and 84 non-engorged ticks. Borrelia DNA was detected in 24 engorged ticks (23%) and 26 non-engorged ticks (31%). This difference was not significant (P = 0.25). Four species of B. burgdorferi sensu lato were identified in the ticks. B. burgdorferi sensu stricto, Borrelia garinii, Borrelia afzelii and group VS116. B. afzelii was most commonly found and present in 13 mixed infections, and in 28 single infections. Fifteen sera (13%) contained antibodies to Borrelia spp. Ticks are more appropriate sentinel animals for Lyme borreliosis than roe deer, an important host for I. ricinus. Although the viability of borrelia spirochaetes in engorged ticks collected from roe deer was not assessed, a bloodmeal taken from roe deer did not eliminate borrelia spirochaetes from the tick. The relevance of this finding for transovarial transmission of borrelia spirochaetes in ticks is discussed.

Identification of four genomic groups of Borrelia burgdorferi sensu lato in Ixodes ricinus ticks collected in a Lyme borreliosis endemic region of northern Croatia.

We investigated the presence of Borrelia burgdorferi sensu lato in Ixodes 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 from the internal transcribed spacer (ITS2) of I. ricinus was detected in all tick lysates, indicating that PCR inhibitors were not present. Borrelia burgdorferi sensu lato 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 sensu stricto (n = 1). Mixed infections of B. afzelii with group VS116 (n = 10) and B. afzelii with B. burgdorferi sensu stricto (n = 1) were also detected. Eight ticks contained B. burgdorferi sensu lato, which could not be typed. The detection of B. afzelii and B. garinii in ticks was in agreement with manifestations of LB found locally. The occurrence of group VS116 in northern Croatia and in an earlier study in The Netherlands, infers that this genomic group may be well established in European I. ricinus.