Characterization of Orientia tsutsugamushi strains isolated in Shandong Province, China by immunofluorescence and restriction fragment length polymorphism (RFLP) analyses.
In order to identify the characteristics of the Sta56 gene of the 23 isolates of Orientia (O.) tsutsugamushi isolated in Shandong Province, indirect immunofluorescence assay (IFA) was used to identify the gene type of 23 strains O. tsutsugamushi isolated from scrub typhus patients, chigger mites, and rodents. Restriction fragment length polymorphism (RFLP) analysis was also used to analyze the restriction profiles of the Sta56 gene PCR amplification products of the 23 isolated strains of the O. tsutsugamushi; the results were compared with those acquired by nested PCR. By IFA, 21 of the 23 isolates belonged to the Gilliam type, and 2 to the Karp type. Using RFLP analysis, 21 strains had similar restriction profiles to the Japan Kawasaki strain, but they had no restriction site Hha I, and thus had some difference in gene sequence compared with the Japan Kawasaki strain. The other 2 strains had similar restriction profiles to Karp. These results were identical to that acquired by nested-PCR. In Shandong Province, the gene types of epidemic O. tsutsugamushi strains were similar to the Japan Kawasaki type, but had some differences in gene sequence. In addition, Karp also existed.
Liu
Yun-xi
YX
School of Public Health, Shandong University, Jinan, PR China.
Zhao
Zhong-tang
ZT
Gao
Yuan
Y
Jia
Chong-qi
CQ
Zhang
Jing-lan
JL
Yang
Zhan-qing
ZQ
Wang
Shu-mei
SM
Jiang
Bao-fa
BF
D000818:Animals; D001179:Arthropod Vectors; D001733:Bites and Stings / Q000382:microbiology; D002681:China / Q000453:epidemiology; D015200:Fluoroimmunoassay / Q000379:methods*; D051379:Mice; D012285:Orientia tsutsugamushi / Q000235:genetics* / Q000302:isolation & purification*; D012150:Polymorphism, Restriction Fragment Length; D012612:Scrub Typhus / Q000453:epidemiology / Q000382:microbiology* / Q000635:transmission; D014324:Trombiculidae / Q000382:microbiology