Department of Veterinary Medicine, University of Perugia, 06126, Perugia, Italy.
Utrecht Centre for Tick-borne Diseases, FAO Reference Centre for Ticks and Tick-borne Diseases, Faculty of Veterinary Medicine, Utrecht University, Yalelaan 1, 3584 CL, Utrecht, The Netherlands.
Parasit Vectors. 2018 Sep 3;11(1):494. doi: 10.1186/s13071-018-3075-2.
Tick-borne rickettsial pathogens are emerging worldwide and pose an increased health risk to both humans and animals. A plethora of rickettsial species has been identified in ticks recovered from human and animal patients. However, the detection of rickettsial DNA in ticks does not necessarily mean that these ticks can act as vectors for these pathogens. Here, we used artificial feeding of ticks to confirm transmission of Rickettsia massiliae and Rickettsia raoultii by Rhipicephalus sanguineus (sensu lato) and Dermacentor reticulatus ticks, respectively. The speed of transmission was also determined.
An artificial feeding system based on silicone membranes were used to feed adult R. sanguineus (s.l.) and D. reticulatus ticks. Blood samples from in vitro feeding units were analysed for the presence of rickettsial DNA using PCR and reverse line blot hybridisation.
The attachment rate of R. sanguineus (s.l.) ticks were 40.4% at 8 h post-application, increasing to 70.2% at 72 h. Rickettsia massiliae was detected in blood samples collected 8 h after the R. sanguineus (s.l.) ticks were placed into the in vitro feeding units. D. reticulatus ticks were pre-fed on sheep and subsequently transferred to the in vitro feeding system. The attachment rate was 29.1 % at 24 h post-application, increasing to 43.6 % at 96 h. Rickettsia raoultii was detected in blood collected 24 h after D. reticulatus was placed into the feeding units.
Rhipicephalus sanguineus (s.l.) and D. reticulatus ticks are vectors of R. massiliae and R. raoultii, respectively. The transmission of R. massiliae as early as 8 h after tick attachment emphasises the importance of removing ticks as soon as possible to minimise transmission. This study highlights the relevance of in vitro feeding systems to provide insight into the vectorial capacity of ticks and the dynamics of tick-borne pathogen transmission.
蜱传立克次体病原体在全球范围内不断出现，给人类和动物的健康带来了更大的风险。从人类和动物患者中分离出的蜱中已经鉴定出了大量的立克次体物种。然而，在蜱中检测到立克次体 DNA 并不一定意味着这些蜱可以作为这些病原体的传播媒介。在这里，我们使用人工饲养蜱的方法来确认 Rhipicephalus sanguineus（广义）和 Dermacentor reticulatus 蜱分别传播 Rickettsia massiliae 和 Rickettsia raoultii。还确定了传播速度。
使用基于硅树脂膜的人工饲养系统来饲养成年 R. sanguineus（广义）和 D. reticulatus 蜱。使用 PCR 和反向线杂交从体外饲养单位的血液样本中分析立克次体 DNA 的存在。
R. sanguineus（广义）蜱在应用后 8 小时的附着率为 40.4%，72 小时时增加到 70.2%。在 R. sanguineus（广义）蜱放入体外饲养单位 8 小时后，从血液样本中检测到 Rickettsia massiliae。预先在绵羊上喂食的 D. reticulatus 蜱随后转移到体外饲养系统。应用后 24 小时的附着率为 29.1%，96 小时时增加到 43.6%。在 D. reticulatus 蜱放入饲养单位 24 小时后，从血液样本中检测到 Rickettsia raoultii。
Rhipicephalus sanguineus（广义）和 D. reticulatus 蜱分别是 R. massiliae 和 R. raoultii 的传播媒介。在蜱附着后 8 小时即可传播 R. massiliae，这强调了尽快去除蜱以最大程度减少传播的重要性。本研究强调了体外饲养系统对于深入了解蜱的传播能力和蜱传病原体传播动态的相关性。
