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ARS Home » Plains Area » Manhattan, Kansas » Center for Grain and Animal Health Research » ABADRU » Research » Publications at this Location » Publication #351872

Research Project: Orbivirus Pathogenesis, Epidemiology, and Control Measures

Location: Arthropod-borne Animal Diseases Research

Title: The role of gut bacteria in Schmallenberg virus transmission by Culicoides biting midges

Author
item Mahlmann, Tim
item Vogels, Chantal
item Drolet, Barbara
item Hendriks, Marc
item Nijhuis, Els
item Van Overbeek, Leo
item Ter Braak, Cajo
item Warris, Sven
item Koenraadt, Constantianus

Submitted to: Meeting Abstract
Publication Type: Abstract Only
Publication Acceptance Date: 3/2/2018
Publication Date: 4/5/2018
Citation: Mahlmann, T., Vogels, C., Drolet, B.S., Hendriks, M., Nijhuis, E., Van Overbeek, L., Ter Braak, C., Warris, S., Koenraadt, C. 2018. The role of gut bacteria in Schmallenberg virus transmission by Culicoides biting midges. Meeting Abstract. 04/05/2018;Lelystand, NL.

Interpretive Summary:

Technical Abstract: When an arbo-virus enters a vector it will first enter the gut system of this insect before entering cells of the insect body. Once in the gut-system, arbo-viruses and gut microbiota can interact with each other. We wondered if different gut bacterial communities could influence virus infection of biting midges. Indeed we show that gut bacteria change the vector competence of biting midges. To better understand the role that gut bacteria can play in virus-vector interactions, we first mapped the gut bacteria of Culicoides nubeculosus midges. Midges were divided in two groups; one group with antibiotic treatment and one control group. After DNA extraction from pools of five midge abdomen, the 16s rRNA bacterial region was amplified and subsequently sequenced using Illumina MiSeq. Sequence data was analysed and the relative abundance of bacterial OTUs were compared. Second, we performed a vector competence experiment in which we again altered the midges gut microbiota via antibiotic treatment. Two species of biting midges (C. nubeculosus and C. sonorensis) were fed on cattle blood mixed with Schmallenberg virus (SBV) after three to six days of treatment with antibiotics. After a ten day incubation period, individual midges were tested for infection with an end-point dilution assay (EPDA) on Vero cells. The bacterial composition in the gut of C. nubeculosus changed significantly after antibiotic treatment. In these midges a diverse number of bacteria could be identified. In contrast, the control group had only one bacteria from the order Acetobacteraceae had the highest relative abundance with up to 98% of all bacteria identified. Although bacterial diversity was higher in the gut of antibiotic treated midges, their overall bacterial load was lower than the control. Interestingly, when both species of Culicoides were tested for vector competence to SBV, the number of infected midges was approximately two times higher in the antibiotic treatment group compared to the control. With this we show that vector competence of Culicoides biting midges can be significantly changed through alteration of the bacterial gut composition.