[Study on the coinfection status of Borrelia burgdorferi sensu lato and spotted fever group Rickettsia in ticks from Hunchun, Jilin province].
OBJECTIVE
To understand the coinfection status of Borrelia burgdorferi sensu lato (B.b.s.l) and spotted fever group Rickettsia (SFGR) in Hunchun of Jilin province, China.


METHODS
Polymerase chain reaction (PCR) was used to detect the 5S-23S rRNA intergenic spacer of B. b. s. l and ompA of SFGR in ticks was collected in Hunchun,Jilin province. The amplification products of positive ticks were sequenced, and phylogenetic analysis was conducted by PHYLIP software package.


RESULTS
The infection rate of B. b. s. l was 36.0% in Ixodes persulcatus ticks and the SFGR was discovered in I. persulcatus ticks,with an infection rate of 2.0%. The coinfection rate of both agents was 2.0%. In 327 Dermacentor siltarum ticks, the positive rates of B. b. s. l and SFGR were 30.9% and 29.1% respectively. 55 ticks (16.8%) were coinfected with the two pathogens. The sequence analysis of B. b. s. l showed that the B. b. s. l in Jilin area, which were highly homologous, all belonged to B. garinii genotypes. The sequence analysis of SFGR positive products showed that the DNA secquence of the newly detected agent (JL-95) was close to the two previously described rickettsiae which were detected in I. ricinus from Slovakia (called IRS3 and IRS4). Phylogenetic relationships inferred from the comparison of these sequences with those of other genus Rickettsiae indicated that JL-95, IRS3 and IRS4 constituted a new rickettsial genotype and formed a separate cluster among the spotted fever group Rickettsiae.


CONCLUSIONS
Coinfection of B. b. s. l and SFGR existed in Hunchun, Jilin province. The sequencing of specific fragment confirmed a new SFGR which was different from other rickettsiae known in China.
Huang
Hai-nan
HN
State Key Laboratory of Pathogen and Biosecurity, Beijing Institute of Microbiology and Epidemiology, Beijing 100071, China.
Ding
Zhuang
Z
He
Jing
J
Wu
Xiao-ming
XM
Jiang
Bao-gui
BG
Gao
Yan
Y
Chu
Chen-yi
CY
Zhan
Lin
L
Zhao
Qiu-min
QM
Wang
Yu-fu
YF
Cao
Wu-chun
WC
D000818:Animals; D015748:Borrelia burgdorferi Group / Q000235:genetics* / Q000302:isolation & purification; D002681:China; D004269:DNA, Bacterial / Q000032:analysis; D005838:Genotype; D008193:Lyme Disease / Q000662:veterinary; D010802:Phylogeny; D016133:Polymerase Chain Reaction; D012281:Rickettsia / Q000235:genetics* / Q000302:isolation & purification; D012282:Rickettsia Infections / Q000662:veterinary; D013987:Ticks / Q000382:microbiology*
D004269:DNA, Bacterial