Summary Many important pathogens maintain significant populations in highly disparate disease and non‐disease environments. The consequences of this environmental heterogeneity in shaping the ecological and evolutionary dynamics of these facultative pathogens are incompletely understood. Agrobacterium tumefaciens , the causative agent for crown gall disease of plants has proven a productive model for many aspects of interactio...

High‐throughput sequencing is revealing that most macro‐organisms house diverse microbial communities. Of particular interest are disease vectors whose microbiome could potentially affect pathogen transmission and vector competence. We investigated bacterial community composition and diversity of the ticks Dermacentor variabilis ( n = 68) and Ixodes scapularis ( n = 15) and blood of their shared rodent host, Peromyscus leucopu...

To quantify microbial composition and interactions, we identified prokaryotic communities in the lone star tick ( Amblyomma americanum ) based on 16S rRNA gene sequences and direct probing. The lone star tick is the vector of emerging diseases and host to additional symbionts of unknown activity, and is representative of other blood‐sucking arthropods. We evaluated the potential for vertical (transovarial) transmission by mole...

Summary Marine sponges are hosts to diverse and dense bacterial communities and thus provide a potential environment for quorum sensing. Quorum sensing, a key factor in cell–cell communication and bacterial colonization of higher animals, might be involved in the symbiotic interactions between bacteria and their sponge hosts. Given that marine Proteobacteria are known to produce N ‐acyl homoserine lactone (AHL) signal molecule...