LAUSR

ABSTRACT In addition to the direct issues associated with the parasitic association between ticks and cattle, approximately 20 million heads of cattle are exposed to diseases. The main goals of this study were to assess the diversity of a cultured microbiota associated with endemic bovine tick species and to identify bacterial isolates with antagonistic activity against five pathogens of medical concern. Twenty-five ticks were collected at six localities of Nuevo León and Zacatecas, Mexico. The exterior surface of the ticks was sterilized, and samples of tissues were streaked onto TSA. The isolates were identified by MALDI-TOF MS. The ticks were identified as Rhipicephalus microplus (90/60%), Amblyomma cajennense (10/6.66%), and Otobius megnini (50/33.3). Two hundred ninety-three different bacterial isolates were obtained, most of which were isolated from R. microplus (160/54.6%). Among the bacterial isolates from ticks, gram-negative bacteria were slightly more prevalent (152/51.87%) than gram-positive bacteria (141/48.12%) in the microbiota, and Firmicutes and Gammaproteobacteria were the dominant taxa, respectively. Bacillus cereus showed the highest prevalence, and Burkholderia cepacia and Serratia marcescens showed an ability to inhibit pathogens. This is the first report of the genus Cronobacter and the species Acinetobacter pittii, Escherichia vulneris, and Enterobacter cloacae being detected in ticks.