CHARACTERIZATION OF RICKETTSIA-TSUTSUGAMUSHI STRAINS IN 2 SPECIES OF NATURALLY INFECTED, LABORATORY-REARED CHIGGERS
CHARACTERIZATION OF RICKETTSIA-TSUTSUGAMUSHI STRAINS IN 2 SPECIES OF NATURALLY INFECTED, LABORATORY-REARED CHIGGERS
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DOI：
10.4269/ajtmh.1982.31.395
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发表时间：
1982-01-01
影响因子：
3.3
通讯作者：
GAN, E
中科院分区：
文献类型：
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作者：
SHIRAI, A;HUXSOLL, DL;GAN, E
通过直接免疫荧光 (FA) 以及小鼠和猴子毒力测试对自然感染的实验室饲养的细螨和弗氏恙虫病中发现的恙虫病菌株进行了表征。 L. arenicola chiggers 中存在的菌株由 TA716、TA763、TA686、Karp 和 Kato 的不同组合组成。除了这 5 种菌株之外，在弗莱切利恙螨中还发现了 Gilliam。结果表明，个体恙螨可以同时感染恙虫病的几种抗原菌株。尽管当观察几代时，这些抗原似乎在家族系内保持稳定，但在连续两代中观察到的抗原模式并不总是相关。抗原的这种可变表达被认为是由于立克次体菌株从一代到下一代的数量波动以及直接 FA 测试在检测少量抗原不同的立克次体时缺乏敏感性。表型变异被认为是不太可能的解释。被任一物种的个体恙螨喂养的 ICR 小鼠的发病率和死亡率都很低，但感染率为 85-99%。与从感染弗莱切里氏菌的小鼠制备的组织悬浮液相比，从受沙粒乳杆菌感染的小鼠制备的组织悬浮液在小鼠中产生更高的死亡率和更长的患病时间。银叶猴和食蟹猴被两种恙螨喂食或接种小鼠组织悬浮液。在这两种情况下，都观察到了最小的临床反应。
The strains of R. tsutsugamushi found in naturally infected, laboratory-reared Leptotrombidium arenicola and L. fletcheri chiggers were characterized by direct immunofluorescence (FA) and by mouse and monkey virulence tests. The strains existing in the L. arenicola chiggers consisted of different combinations of TA716, TA763, TA686, Karp and Kato. In addition to these 5 strains, Gilliam was found in the L. fletcheri chiggers. Results indicate that individual chiggers can be simultaneously infected with several antigenic strains of R. tsutsugamushi. Although these antigens appear to remain stable within familial lines when several generations were viewed, the antigenic patterns observed in 2 succeeding generations did not always correlate. This variable expression of antigens was considered to be due to a quantitative fluctuation from 1 generation to the next in the strains of rickettsiae combined with a lack of sensitivity of the direct FA test in detecting small numbers of antigenically different rickettsiae. Phenotypic variation was considered to be a less probable explanation. Morbidity and mortality were minimal in ICR mice fed upon by individual chiggers of either species, but infection rates were 85-99%. Tissue suspensions prepared from mice infected by L. arenicola produced higher mortality and longer duration of illness in mice than those prepared from L. fletcheri-infected mice. Silvered leaf and cynomolgus monkeys were fed upon by the 2 species of chiggers or inoculated with the mouse tissue suspensions. In both cases, minimal clinical responses were observed.