Genomic and Proteomic Analyses of Bacterial Communities of Ixodes scapularis Ticks from Broome County, New York.

The microbial communities of Ixodes scapularis, the primary vector of Lyme disease in North America, exhibit regional variations that may affect pathogen transmission and vector competence. We analyzed bacterial communities in I. scapularis ticks collected from Broome County, New York, using 16S rRNA gene sequencing (18 ticks) as well as mass spectrometry-based proteomics (36 ticks). According to the 16S rRNA analysis, the endosymbiont Rickettsia buchneri was the most abundant species, with significantly higher (p = 0.0011) abundance in females (54.76%) compared to males (31.15%). We detected Borreliella burgdorferi in 44.44% of ticks and Anaplasma phagocytophilum in two nymphs but in high relative abundances (12.73% and 46.46%). Male ticks exhibited higher bacterial diversity, although the community composition showed no significant clustering by sex or life stage. Co-occurrence analysis revealed negative associations between R. buchneri and Pseudomonas (p = 0.0245), but no associations with B. burgdorferi. Proteomic analysis identified 12 R. buchneri-specific proteins, additionally detecting the protozoan pathogen Babesia microti in 18.18% of females. These findings provide the first comprehensive characterization of I. scapularis microbiomes in the Southern Tier region of New York and suggest broader distribution of R. buchneri across tick life stages than previously recognized, with potential implications for pathogen transmission dynamics.