Effects of antibiotic treatment on the fecundity of Rhipicephalus haemaphysaloides ticks

Abstract

BackgroundEndosymbiotic bacteria inhabit a variety of arthropods including ticks and may have multiple effects on the host’s survival, reproduction or pathogen acquisition and transmission. Rhipicephalus haemaphysaloides is one of the most widely distributed tick species in China. The symbiotic bacteria composition and their impacts to R. haemaphysaloides ticks have not been studied. The present study investigated the composition of microbial community in R. haemaphysaloides ticks and then assessed the effects of endosymbionts on the host’s fecundity by antibiotic treatment experiments.MethodsThe microbial population of female and male R. haemaphysaloides ticks was analyzed using Illumina Miseq sequencing of 16S rRNA gene. Thirty engorged female ticks were then randomly divided into five groups and injected with ampicillin, ciprofloxacin, kanamycin, tetracycline, or phosphate-buffered solution (PBS), respectively. Effects of antibiotic treatments on maternal oviposition, egg hatching and density of endosymbionts were evaluated.ResultsIllumina Miseq sequencing showed that Coxiella and Rickettsia were the predominant bacterial genera inhabiting R. haemaphysaloides ticks. Antibiotic treatment experiments found that kanamycin reduced the density of Coxiella-like endosymbiont (Coxiella-LE hereafter) in eggs, ciprofloxacin reduced the density of Rickettsia-like endosymbiont (Rickettsia-LE), and tetracycline had effect on both endosymbionts, while ampicillin affected neither. Meanwhile hatching rates of eggs were observed to decrease greatly in the kanamycin or tetracycline-treated group but maintained in the ampicillin or ciprofloxacin-treated group. Furthermore, the reduced hatching rates were found to be associated with density of Coxiella-LE in eggs.ConclusionsThe findings indicate that Coxiella-LE is essential for the reproduction of R. haemaphysaloides ticks, and that kanamycin can be used to study the role of Coxiella-LE on ticks.

Endosymbionts carried by ticks feeding on dogs in Spain

“…As previously described by Li et al (2018), our results confirm that Coxiella and Rickettsia were the predominant genera in feeding collected ticks. The explanation of this finding could be that these genera were transovarially transmitted, in contrast to other tick endosymbionts that are often obtained from the environment.…”

“…We acknowledge that the only way to establish congruent relationships among the detected bacteria, regarding possible events of transmission impairment, is to evaluate the physiological parameters of tick colonies with controlled endosymbiont faunal composition together with dedicated laboratory protocols. However, the presence of R. massiliae in R. sanguineus s.l could act similarly to rickettsial infections in D. variabilis, in which the inhibition of the transovarial transmission of a second Rickettsia has been reported (Ahantarig et al, 2013;De la Fuente et al, 2017;Li et al, 2018;Narasimhan and Fikrig, 2015;Zhong et al, 2007). Although R. massiliae is widespread in R. sanguineus s.l., it has also been recorded in I. ricinus (Bazzocchi et al, 2013;Bonnet et al, 2017;Epis et al, 2008).…”

“…pools. This rickettsial endosymbiont is included into the spotted fever group, which also includes R. raoultii, Rickettsia aeschlimannii, and Rickettsia rhipicephali (Chisu et al, 2018;Li et al, 2018;Moutailler et al, 2016;Papa et al, 2017;Zhong et al, 2007). Previous studies linked R. massiliae to cases of mild illnesses in dogs in California, and could cause spotted fever in human (Beeler et al, 2011;Chisu et al, 2018).…”

Endosymbionts Alter Larva-to-Nymph Transstadial Transmission of Babesia microti in Rhipicephalus haemaphysaloides Ticks

“…Nine engorged female ticks were randomly assigned to three treatment groups and injected with ciprofloxacin (10 mg/ml), kanamycin (10 mg/ml) or PBS separately, as described previously ( Li et al, 2018 ). In brief, engorged female ticks were injected at the hemocoel between the first and second legs using a Hamilton microinjection syringe (Hamilton Co., Bonaduz, Switzerland).…”

“…Rhipicephalus haemaphysaloides , a widely distributed tick species in China ( Chen et al, 2010 ; Yu et al, 2015 ), has been proven to be a vector of B. microti ( Li et al, 2016 ). Our previous study revealed that Rickettsia and Coxiella -like endosymbionts ( Rickettsia -LE and Coxiella -LE hereafter) inhabit R. haemaphysaloides ticks ( Li et al, 2018 ). However, the potential effects of endosymbionts on pathogen susceptibility in this tick species have not been investigated before.…”