Wang Zhongming, Zhang Xiaolong, Li Chunxiao, Zhang Yingmei, Xin Dan, Zhao Tongyan
State Key Laboratory of Pathogens and Biosecurity, Institute of Microbiology and Epidemiology, Beijing, 100071, PR China.
J Vector Ecol. 2010 Dec;35(2):313-7. doi: 10.1111/j.1948-7134.2010.00088.x.
Two western equine encephalomyelitis virus (WEEV) strains have been isolated in China. Our previous studies have verified that the mosquito Culex pipiens pallens Coquillett (Diptera: Culicidae) infected with WEEV was capable of transmitting this arbovirus, but it was not clear how the sequential multiplication and spread of virus occurred within the mosquito. In this study, we observed the distribution of WEEV antigen in orally-infected Cx. p. pallens by immunohistochemistry in order to better understand the initial infection, dissemination, and transmission of WEEV in the potential vector. Orally-infected WEEV dissemination varied within the different tissues of Cx. p. pallens, with virus antigen consistently observed in the salivary glands, foregut, midgut epithelial cells, Malpighian tubules, hindgut, and ovarian follicles of some individuals after various days of extrinsic incubation. We suggest that Cx. p. pallens, the potential vector of WEEV, has the ability to harbor the virus through the alimentary system, and the midgut epithelial cell may be the initial site of WEEV replication after ingestion of a viremic blood meal.
中国已分离出两株西部马脑炎病毒（WEEV）。我们之前的研究已证实，感染WEEV的致倦库蚊（双翅目：蚊科）能够传播这种虫媒病毒，但尚不清楚病毒在蚊体内的相继增殖和传播过程是如何发生的。在本研究中，我们通过免疫组织化学观察了经口感染WEEV的致倦库蚊体内WEEV抗原的分布情况，以便更好地了解WEEV在潜在传播媒介中的初始感染、传播及传播过程。经口感染后，WEEV在致倦库蚊不同组织中的传播情况各异，在不同天数的外在潜伏期后，在一些个体的唾液腺、前肠、中肠上皮细胞、马氏管、后肠和卵泡中均持续观察到病毒抗原。我们认为，WEEV的潜在传播媒介致倦库蚊有能力通过消化系统携带病毒，并且中肠上皮细胞可能是摄入含病毒血液后WEEV复制的初始部位。
