Le Justin, Thompson Molly B, Yen Wan-Yi, Mishra Smruti, Carlson David, Handel Andrew S, Mackow Erich R, Benach Jorge L, Rochlin Ilia, Kim Hwan Keun
Center for Infectious Diseases, Stony Brook University, Stony Brook, New York.
Department of Microbiology and Immunology, Stony Brook University, Stony Brook, New York.
Am J Trop Med Hyg. 2025 Apr 29;113(1):147-155. doi: 10.4269/ajtmh.24-0782. Print 2025 Jul 2.
Ticks are blood-feeding arthropods and serve as vectors and reservoirs for diverse pathogens. Recent environmental changes have triggered the invasion of ticks into new geographical areas, prompting a public health alert for increased risk of tick-borne diseases. Amblyomma (A.) americanum (lone star tick) has emerged as the most common human-biting tick species in the eastern United States. Amblyomma americanum transmits multiple pathogens, including Rickettsia (R.) amblyommatis, the suspected cause of mild spotted fever rickettsiosis. As an invasive tick species, Haemaphysalis (H.) longicornis (longhorned tick) has rapidly invaded and expanded to high densities in the eastern United States. Haemaphysalis longicornis and A. americanum often share the habitat with preferential feeding on mid- to large-sized animals, such as white-tailed deer. This sympatric association of H. longicornis with A. americanum raises the potential for H. longicornis to acquire pathogens native to A. americanum during blood-feeding on the same host. In its native ranges, H. longicornis transmits R. japonica and R. heilongjiangensis. However, it remains unclear whether H. longicornis can transmit R. amblyommatis abundantly present in A. americanum in the United States. Using artificial membrane feeding, we establish that R. amblyommatis can stably colonize H. longicornis without altering feeding and molting behaviors. Transovarial transmission of R. amblyommatis did not occur in parthenogenetic H. longicornis. However, R. amblyommatis successfully invaded the midgut and salivary glands of H. longicornis, key organ tissues of rickettsial replication and horizontal transmission. Our results suggest that H. longicornis may serve as a vector, but not as a reservoir, for R. amblyommatis transmission.
蜱是吸血节肢动物，是多种病原体的传播媒介和宿主。最近的环境变化引发了蜱向新地理区域的入侵，促使人们对蜱传疾病风险增加发出公共卫生警报。美洲钝眼蜱（孤星蜱）已成为美国东部最常见的叮咬人类的蜱种。美洲钝眼蜱传播多种病原体，包括疑似引起轻度斑点热立克次氏体病的安氏立克次氏体。作为一种入侵性蜱种，长角血蜱已迅速入侵并在美国东部扩散至高密度区域。长角血蜱和美洲钝眼蜱经常共享栖息地，偏好吸食中型至大型动物，如白尾鹿的血液。长角血蜱与美洲钝眼蜱的这种同域关联增加了长角血蜱在同一宿主上吸血时获取美洲钝眼蜱原生病原体的可能性。在其原生范围内，长角血蜱传播日本立克次氏体和黑龙江立克次氏体。然而，尚不清楚长角血蜱是否能传播在美国美洲钝眼蜱中大量存在的安氏立克次氏体。通过人工膜饲喂，我们证实安氏立克次氏体可以稳定地在长角血蜱中定殖，而不改变其取食和蜕皮行为。孤雌生殖的长角血蜱未发生安氏立克次氏体的经卵传播。然而，安氏立克次氏体成功侵入了长角血蜱的中肠和唾液腺，这是立克次氏体复制和水平传播的关键器官组织。我们的结果表明，长角血蜱可能作为安氏立克次氏体传播的媒介，但不是宿主。
