Zent.bl. Bakteriol. 287, 347-361 (1998) © Gustav Fischer Verlag Zentralblatt fUr BakWioloaie Detection of Borrelia burgdorferi in Urine Specim'ens from Dogs by a Nested Polymerase Chain Reaction Rolf Bauerfeind, Ulrich Kreis, Reinhard WeiB, Lothar H. Wieler, and Georg Baljer Institut fur Hygiene und lnfektionskrankheiten der Tiere, Justus-Liebig-Universitat Giessen, Germany Received July 1, 1997· Accepted September 15, 1997 Summary A nested PCR (nested flagellin PCR) carrying an internal E. coli DNA control was es tablished and compared with an in-vitro culture method for the detection of Borrelia burgdorferi in urine specimens of dogs. The predicted specific amplicon of the flagel lin gene fla was generated from all cultured strains of B. burgdorferi tested (compris ing three European genospecies). In contrast, all 13 strains of seven other flagellated bacterial species were negative, The PCR detection limit yielded 20 cells of B. burgdor feri per ml of double-distilled water and approx. 250 bacteria per ml of dog urine. Us ing the bacterial culture method, urine specimens collected from 216 dogs in Germa ny were all diagnosed negative for spirochetes by in-vitro culture and dark-field mi croscopy. In contrast, DNA of B, burgdorferi was detected in 32 specimens (14,8%) by PCR. 31 urine specimens (14.4%) showed inhibitory activity in the PCR assay. However, 94 (44%) were inhibitory in the culture assay. The majority of the PCR positive dogs exhibited major clinical symptoms which have not been reported in the course of B. burgdorferi infection previously, e. g. cystitis (14/32 dogs) or prostatitis (51 32 dogs). Our results indicate that the analysis of urine specimens by the nested flagel lin PCR is a highly valuable procedure for the diagnosis of B. burgdorferi infections in dogs. Introduction Borrelia burgdorferi sensu lato, the causative agent of the tick-borne Lyme disease, is well established as an important zoonotic pathogen which affects diverse vertebrate host species, including humans, dogs and equidae (Burg-