吉林省珲春地区蜱中伯氏疏螺旋体与斑点热群立克次体复合感染研究

目的了解吉林省珲春地区伯氏疏螺旋体与斑点热群立克次体的复合感染情况.方法运用PCR方法对吉林省珲春地区采集的蜱标本,进行伯氏疏螺旋体5S～23S rRNA间隔区基因与斑点热群立克次体外膜蛋白A（ompA）基因的检测.测序并用PHYLIP软件进行序列分析.结果全沟硬蜱中伯氏疏螺旋体感染率为36.0%,在全沟硬蜱中检测到了斑点热群立克次体的感染,其感染率为2 0%.二者的复合感染率为2.0%;森林革蜱中伯氏疏螺旋体感染率30.9%,斑点热群立克次体感染率29.1%,二者的复合感染率16.8%.伯氏疏螺旋体的序列分析显示吉林地区的伯氏疏螺旋体都属于B.garinii基因型,同源性较高.对斑点热阳性片段序列分析表明新测序列与斯洛伐克新发现的IRS3株和IRS4株核苷酸序列同源性为97%.结论吉林省珲春地区全沟硬蜱及森林革蜱中检测到伯氏疏螺旋体与斑点热群立克次体的感染,并检测到2种病原体的复合感染情况.

Study on the coinfection status of Borrelia burgdorferi sensu iato 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. 1 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 silvarum 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 J. 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. Conclusion 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.