Detection and Identification of Species-Specific Bacteria Associated with Synanthropic Mites

Abstract

Internal bacterial communities of synanthropic mites Acarus siro, Dermatophagoides farinae, Lepidoglyphus destructor, and Tyrophagus putrescentiae (Acari: Astigmata) were analyzed by culturing and culture-independent approaches from specimens obtained from laboratory colonies. Homogenates of surface-sterilized mites were used for cultivation on non-selective agar and DNA extraction. Isolated bacteria were identified by sequencing of the 16S rRNA gene. PCR amplified 16S rRNA genes were analyzed by terminal restriction fragment length polymorphism analysis (T-RFLP) and cloning sequencing. Fluorescence in situ hybridization using universal bacterial probes was used for direct bacterial localization. T-RFLP analysis of 16S rRNA gene revealed distinct species-specific bacterial communities. The results were further confirmed by cloning and sequencing (284 clones). L. destructor and D. farinae showed more diverse communities then A. siro and T. putrescentiae. In the cultivated part of the community, the mean CFUs from four mite species ranged from 5.2 × 10(2) to 1.4 × 10(3) per mite. D. farinae had significantly higher CFUs than the other species. Bacteria were located in the digestive and reproductive tract, parenchymatical tissue, and in bacteriocytes. Among the clones, Bartonella-like bacteria occurring in A. siro and T. putresecentiae represented a distinct group related to Bartonellaceae and to Bartonella-like symbionts of ants. The clones of high similarity to Xenorhabdus cabanillasii were found in L. destructor and D. farinae, and one clone related to Photorhabdus temperata in A. siro. Members of Sphingobacteriales cloned from D. farinae and A. siro clustered with the sequences of "Candidatus Cardinium hertigii" and as a separate novel cluster.

Experimental Manipulation Shows a Greater Influence of Population than Dietary Perturbation on the Microbiome of Tyrophagus putrescentiae

“…The presence of Enterobacteriaceae taxa in T. putrescentiae raises the question of whether these bacterial taxa are symbiotic in the mite. Previously, we observed sequences with 99% similarity to Xenorhabdus cabanillasii among clones from L. destructor and A. siro (10), whereas sequences similar to those of Erwinia bacteria comprised the majority of the microbiome of Blomia tropicalis (9). "Candidatus Erwinia dacicola" resides intracellularly in the gastric ceca of the larval midgut but extracellularly in the lumen of the foregut and the ovipositor diverticulum in adult flies (27).…”

“…More recently, horizontal Wolbachia transfer between Drosophila melanogaster stocks facilitated by Tyrophagus putrescentiae has been reported; moreover, this transmission occurred through the ingestion of Wolbachia in infested corpses (8). However, Rickettsia has not yet been identified in domestic mites (9,10).…”

<p align="center"><strong>A review of prevalence and phylogeny of the bacterial symbiont <em>Cardinium</em> in mites (subclass: Acari)</strong></p>

“…Thus, the detection of its presence in mites is done mainly using PCR-based techniques, sometimes aided by bioassays (crossing breeding studies). Available molecular markers for its detection in mites include, but not limited to, the 16S ribosomal RNA (16S rRNA) and the Gyrase B (gyrB) (Hoy & Jeyaprakash 2005;Chigira & Miura 2005;Liu et al 2006;Novelli et al 2007;Enigl & Schausberger 2007;Novelli et al 2008;Chen et al 2009;Moro et al 2009b;Jeong et al 2009;Ros et al 2012;Zhu et al 2012b;Zhao et al 2013a;Zhao et al 2013b;Hubert et al 2012;Famah Sourasson et al 2014). The other techniques used to determine the presence and distribution of Cardinium in mites are transmission electron microscopy (Kitajima et al 2007) and fluorescence in situ hybridization (Zhu et al 2012a).…”

Studies of house dust mites can now fully embrace the “-omics” era

“…Despite these caveats, however, species from several of the gram-negative and gram-positive genera identified by the authors have previously been isolated from mites by using conventional culture techniques, as well as 16S ribosomal DNA sequencing techniques, 8,9 suggesting that there is a ''core'' microbiome. The previously reported bacteria include Enterobacter species, Bacillus species, Staphylococcus species, Rhizobium species, Bartonella species, E coli, Pseudomonas species, and Acinetobacter species.…”