Replication Kinetics of Rickettsia raoultii in Tick Cell Lines

Microorganisms

Lesley Bell-Sakyi¹  Mulya Mustika Sari Zulkifli²  Sazaly AbuBakar²  Jing Jing Khoo²  Nurul Aini Husin² 

[1] Department of Infection Biology and Microbiomes, Institute of Infection, Veterinary and Ecological Sciences, University of Liverpool, Liverpool L3 5RF, UK;Tropical Infectious Diseases Research and Education Centre, Level 2, High Impact Research Building, Universiti Malaya, Kuala Lumpur 50603, Malaysia;

关键词: vector-borne disease;    Rickettsia raoultii;    infectious disease;    tick cell line;   

DOI  :  10.3390/microorganisms9071370

来源: DOAJ

【 摘 要 】

Rickettsia raoultii is one of the causative agents of tick-borne lymphadenopathy in humans. This bacterium was previously isolated and propagated in tick cell lines; however, the growth characteristics have not been investigated. Here, we present the replication kinetics of R. raoultii in cell lines derived from different tick genera (BME/CTVM23, RSE/PILS35, and IDE8). Tick cell cultures were infected in duplicate with cryopreserved R. raoultii prepared from homologous cell lines. By 12–14 days post infection, 100% of the cells were infected, as visualized in Giemsa-stained cytocentrifuge smears. R. raoultii growth curves, determined by rickettsiae-specific gltA qPCR, exhibited lag, exponential, stationary and death phases. Exponential phases of 4–12 days and generation times of 0.9–2.6 days were observed. R. raoultii in BME/CTVM23 and RSE/PILS35 cultures showed, respectively, 39.5- and 37.1-fold increases compared to the inoculum. In contrast, multiplication of R. raoultii in the IDE8 cultures was 110.1-fold greater than the inoculum with a 7-day stationary phase. These findings suggest variation in the growth kinetics of R. raoultii in the different tick cell lines tested, amongst which IDE8 cells could tolerate the highest levels of R. raoultii replication. Further studies of R. raoultii are needed for a better understanding of its persistence within tick populations.

【 授权许可】

Unknown