Rickettsiae Within the Fleas of Feral Cats in Galveston, Texas
Rickettsiae Within the Fleas of Feral Cats in Galveston, Texas
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DOI：
10.1089/vbz.2018.2402
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发表时间：
2019-09-01
影响因子：
2.1
通讯作者：
Bouyer, Donald H.
中科院分区：
文献类型：
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作者：
Blanton, Lucas S.;Vohra, Rahat F.;Bouyer, Donald H.
鼠斑疹伤寒是由斑疹伤寒立克次体引起的蚤传斑疹伤寒群立克次体病。20世纪40年代，二氯二苯三氯乙烷的使用打破了典型的鼠-鼠蚤传播循环，现在认为其余的地方病疫源地与负鼠和猫蚤（猫蚤）有关。在德克萨斯州加尔维斯顿，鼠斑疹伤寒作为发热性疾病的一种原因再次出现，从负鼠身上收集的跳蚤中有7%感染了斑疹伤寒。在这项研究中，我们试图探索与猫跳蚤相关的立克次体的流行，因为这些动物被推测在鼠斑疹伤寒的流行病学中发挥作用。从进入当地兽医诊所的野猫身上收集跳蚤，作为诱捕、绝育和释放计划的一部分。对蚤类进行鉴定，并进行PCR和测序分析。对合并样本的最小感染率（MIR）进行估计。从24只猫身上采集到314只蚤（均为猫蚤）。外膜蛋白B基因序列显示斑疹伤寒1个库（MIR 0.3%），猫立克次体4个库（MIR 1.3%），集散立克次体1个库（MIR 0.3%），塞内加尔候选菌6个库（MIR 2.0%）。结果通过对柠檬酸立克次体合成酶和17-kD蛋白基因的部分测序得到证实。在本研究中，猫身上跳蚤中伤寒杆菌的存在表明，在加尔维斯顿，与跳蚤感染的猫接触的人存在很小但可测量的风险。尽管如此，我们认为，与以前从负鼠身上检测到的跳蚤相比，猫收集的跳蚤的流行率较低，这使得猫不太可能在该地区维持斑疹伤寒的作用。其他已鉴定的蚤传立克次体的意义尚待阐明。
Murine typhus is a flea-borne typhus group rickettsiosis caused by Rickettsia typhi. Once a prevalent disease in the United States, the use of dichlorodiphenyltrichloroethane in the 1940s broke the classic rat-rat flea cycle of transmission, and the remaining endemic foci are now believed to be associated with opossums and the cat flea (Ctenocephalides felis). In Galveston, Texas murine typhus has re-emerged as a cause of febrile illness, and 7% of fleas collected from opossums are infected with R. typhi. In this study, we sought to explore the prevalence of rickettsiae associated with fleas on cats, as these animals have been speculated to play a role in the epidemiology of murine typhus. Fleas were collected from feral cats entering a local veterinary clinic as part of a trap, spay, neuter, and release program. Fleas were identified and subjected to analysis by PCR and sequencing. An estimation of the minimum infection rate (MIR) of pooled samples was performed. Three hundred fourteen fleas (all C. felis) were collected from 24 cats. Sequences for the outer membrane protein B gene revealed R. typhi in one pool (MIR 0.3%), Rickettsia felis in four pools (MIR 1.3%), Rickettsia asembonensis in one pool (MIR 0.3%), and "Candidatus R. senegalensis" in six pools (MIR 2.0%). Results were confirmed by sequencing portions of the rickettsial citrate synthase and 17-kD protein gene. In this study, the presence of R. typhi in fleas from cats suggests that in Galveston, there exists a small but measurable risk to humans who come into contact with flea-infested cats. Despite this, we believe that the low prevalence from cat-collected fleas, compared with that previously detected from opossums, makes cats less likely to play a role in the maintenance of R. typhi in this region. The significance of other identified flea-borne rickettsiae is yet to be elucidated.