Genomic Analysis of Antibiotic Resistance in Microbiota of Honey Bees

The microbiota of an organism plays an essential role in maintaing the health of its host. Gut microbiota serve many functions such as aiding in host immunity and metabolism. When these communities are perturbed, they can deeply affect the livelihood of the host and increase their mortality. Agents such as antibiotics are prime examples of substances that can disrupt the gut microbial communities and weaken the hosts. This ultimately gives opportunistic pathogens the chance to overcome the natural flora. honey bees are excellent models for studying the interactions between antibiotics and gut microbiota and can be used to further our understanding on these interactions as humans. In beekeeping and agriculture, the use of antibiotics is excessive. In beehives specifically, antibiotics such as tetracycline are used for larval protection against pathogens such as Serratia and Foulbrrod. This prolonged exposure to antibiotics suggests the aquistion of antibiotic resistance genes in the microbiota of honey bees. Genomic analysis shows the presence of a family of tetracycline efflux pump genes in two core species, Gilliamella apicola and Snodgrassella alvi, in the honey bee gut. Further genomic anaysis of Serratia isolate from local hives show the presence of MFS efflux pumps. Minimum Inhibitory Concentration assays performed on strains showing genetic markers for tetracycline resistance showed significant colony growth in the presence of antibiotics, even at the highest tested antibiotic concentrations. Further studies that determine precise inhibitory antibiotic concentrations, potential similarity between transpogenic elements and linkage between antibiotic resistance genes, and specific interactions between Serratia strains and core honey bee microbiota species can elucidate lingering questions regarding antibiotics and their effects on the microbiota.