Abstract

Dermanyssus gallinae (Arthropoda, Mesostigmata) is suspected to be involved in the transmission of a wide variety of pathogens, but nothing is known about its associated non-pathogenic bacterial community. To address this question, we examined the composition of bacterial communities in D. gallinae collected from standard poultry farms in Brittany, France. Genetic fingerprints of bacterial populations were generated by temporal temperature gradient gel electrophoresis (TTGE) separation of individual polymerase chain reaction (PCR)-amplified 16S rRNA gene fragments, followed by DNA sequence analysis. Most of the sequences belonged to the Proteobacteria and Firmicute phyla with a majority of species corresponding to the Enterobacteriales order and the Staphylococcus genus. By using statistical analysis, we showed differences in biodiversity between poultry farms. We also determined the major phylotypes that compose the characteristic bacterial flora associated with D. gallinae. Saprophytic species, opportunistic pathogens and pathogenic agents such as Pasteurella multocida, Erysipelothrix rhusiopathiae and species of the genus Aerococcus, were identified. Endosymbionts such as Schineria sp., Spiroplasma sp. Anistosticta, "Candidatus Cardinium hertigii" and Rickettsiella sp. were also present in the sub-dominant bacterial population. Identification of potential targets within the symbiont community may be considered in the future as a means of ectoparasite control.

Keywords : ectoparasite; bacterial community; symbionts; molecular fingerprints