title: [Exploratory study on natural focus and its causative agent of genotype of Lyme disease by polymerase chain reaction in the forest areas of Beijing].
abstract: OBJECTIVE
  To learn the existence of natural focus of Lyme disease and its distribution.
  
  
  METHODS
  A semi-nested polymerase chain reaction (PCR) method was developed for detection and genotyping of Borrelia burgdorferi on basis of outer surface protein A (OspA) gene. Ticks and mice collected from 6 forest areas in Beijing were detected with above methods. The positive PCR products were cloned and sequenced. The sequences were compared with published sequences for homology. IFA as used to detect IgG antibody on Borrelia burgdorferi. Lyme disease spirochete were isolated from H. longicornis were also attempted.
  
  
  RESULTS
  B. Burgdorferi sensu lato were detected from 939 ticks and 250 mice specimens collected from above 6 study sites using primer pairs OA(1)/OA(4) and SL/OA(4). Only the specimens collected from Dongling mountain showed positive amplification. One in three adult Ixodes persulcatus with one of 57 nymph Ixodes persulcatus showed positive while 9 of 119 (7.56%) mice specimens showed positive, of which 8 were B. grinii and one B. afzelii. In this study, we attempted to isolate B. burgdorferi sensu lato strains from 160 H. longicornis ticks (20/group) but failed. Serological survey showed a 9.1% (5/55) infection rate with B. burgdorferi sensu lato in the mice of Dongling mountain forest areas.
  
  
  CONCLUSIONS
  The natural focus of Lyme disease including B. garinii and B. afzelii might have existed in Dongling mountain of Mentougou district, Beijing. Ixodes persulcatu and mice may serve as vectors and reservoirs, respectively.
authors.affiliation: Institute of Microbiology and Epidemiology of Academy of Military Medical Science, Beijing 100071, China.
authors.forename: Jianmin
authors.initials: J
authors.lastname: Li
authors.forename: Wuchun
authors.initials: W
authors.lastname: Cao
authors.forename: Xitan
authors.initials: X
authors.lastname: Zhang
authors.forename: Xiaoming
authors.initials: X
authors.lastname: Wu
authors.forename: Panhe
authors.initials: P
authors.lastname: Zhang
authors.forename: Qiumin
authors.initials: Q
authors.lastname: Zhao
authors.forename: Hong
authors.initials: H
authors.lastname: Yang
authors.forename: Zhenying
authors.initials: Z
authors.lastname: Dong
authors.forename: Shengli
authors.initials: S
authors.lastname: Cai
mesh_terms: D000818:Animals; D000954:Antigens, Surface / Q000235:genetics*; D001425:Bacterial Outer Membrane Proteins / Q000235:genetics*; D001428:Bacterial Vaccines; D025065:Borrelia burgdorferi / Q000235:genetics*; D015748:Borrelia burgdorferi Group / Q000145:classification / Q000235:genetics; D006801:Humans; D018884:Ixodes / Q000382:microbiology; D008074:Lipoproteins; D008193:Lyme Disease / Q000382:microbiology*; D051379:Mice; D010802:Phylogeny; D016133:Polymerase Chain Reaction / Q000379:methods
chemical_list: D000954:Antigens, Surface; D001425:Bacterial Outer Membrane Proteins; D001428:Bacterial Vaccines; D008074:Lipoproteins; C072045:OspA protein