恙虫病立克次体（恙虫东方体）感染印度丛林恙螨（蜱螨亚纲：恙螨科）卵的患病率的时间变化。

Temporal changes in prevalence of scrub typhus rickettsia (Orientia tsutsugamushi) infecting the eggs of Leptotrombidium imphalum (Acari: Trombiculidae).

作者信息

Kollars T M, Kengluecha A, Khlaimanee N, Tanskul P

机构信息

Department of Entomology, U.S. Army Medical Component, Armed Forces Research Institute of Medical Sciences, 315/6 Rajavithi Road, Phya Thai, Bangkok 10400, Thailand.

出版信息

J Med Entomol. 2001 Jan;38(1):108-10. doi: 10.1603/0022-2585-38.1.108.

DOI:10.1603/0022-2585-38.1.108

PMID:11268679

Abstract

Eggs from seven colony lines of the chigger mite Leptotrombidium imphalum (Vercammen-Grandjean & Langston) were examined for infection with Orientia tsutsugamushi (Hyashi), the etiologic agent of scrub typhus. The polymerase chain reaction (PCR) using primers OtP 56.809 and OtM 56.1221, which amplify a 291 bp region of the P56 gene of O. tsutsugamushi, was used to detect scrub typhus within single eggs. All seven chigger mite lines produced infected eggs with varying rates of infection (Li1 = 8.1%, n = 124; Li2 = 45.6%, n = 90; Li3 = 30.1%, n = 144; Li4 = 31.7%, n = 145; Li5 = 21.3%, n = 136; Li6 = 41.6% n = 77; Li7 = 22.5%, n = 110). The 3 wk with the highest infection rates for each line using Fourier analysis were as follows: Li1 = 2, 7, 14; Li2 = 4, 6, 12; Li3 = 3, 6, 12; Li4 = 4, 6, 12; Li5 = 5, 7, 14; Li7 = 4, 6, 12. Li6 only had nine measurements over time; therefore, Li6 was excluded from individual analysis. Infection rates of scrub typhus in eggs occurred in a 2-wk 2-d cycle, using Fourier analysis of combined data. Not only did infection rates vary among the progeny of females, but temporal variation also occurred.

摘要

研究人员检测了恙螨（Leptotrombidium imphalum，Vercammen-Grandjean & Langston）七个群体品系的卵，以确定其是否感染恙虫病东方体（Orientia tsutsugamushi，Hyashi），即恙虫病的病原体。使用引物OtP 56.809和OtM 56.1221进行聚合酶链反应（PCR），该引物可扩增恙虫病东方体P56基因的291 bp区域，用于检测单个卵内的恙虫病。所有七个恙螨品系均产生了感染的卵，感染率各不相同（Li1 = 8.1%，n = 124；Li2 = 45.6%，n = 90；Li3 = 30.1%，n = 144；Li4 = 31.7%，n = 145；Li5 = 21.3%，n = 136；Li6 = 41.6%，n = 77；Li7 = 22.5%，n = 110）。使用傅里叶分析得出，每个品系感染率最高的3周分别如下：Li1 = 第2、7、14周；Li2 = 第4、6、12周；Li3 = 第3、6、12周；Li’4 = 第4、6、12周；Li5 = 第5、7、14周；Li7 = 第4、6、12周。Li6仅进行了9次随时间的测量；因此，Li6被排除在个体分析之外。使用合并数据的傅里叶分析表明，卵中恙虫病的感染率呈2周零2天的周期出现。不仅雌性后代的感染率存在差异，而且还存在时间变化。