Antimicrobial Resistance Profiling of Alligator Gut Microbiome Isolates

Antibiotic resistance research has become urgent due to the lack of development of new antibiotics and the increase in multi-drug resistant bacterial infections, which have become a global threat. Due to its large and diverse microbial population, the gut microbiome has been suggested to be a great candidate for antibiotic resistance research. In a recent study, antibiotic resistance gene elements were identified in samples of the gut of an American alligator. The goal of this project is to confirm antibiotic resistance among potential antibiotic-resistant isolated colonies from these previously mentioned alligator gut samples. Bacteria were isolated from this gut microbiota based on the resistance genes identified using a disk diffusion enrichment approach. The isolates were identified based on their 16S rRNA gene sequences, and we have tested some of these isolated strains for antibiotic resistance using a minimal inhibitory concentration (MIC) assay. The MIC assay was performed to determine antibiotic resistance within these selected strains against antibiotics, Ampicillin, Gentamycin, Tetracycline, Rifampin, Chloramphenicol, Kanamycin, and Ciprofloxacin, which are from different classes with different potencies. We found that six of the strains were multi-drug resistant. We found that Ciprofloxacin was mainly inhibitory to all the tested strains, while Ampicillin and Kanamycin were unable to inhibit any of the strains. Moving forward with this project we hope to successfully link the previously identified antibiotic resistance gene elements to resistance seen within the minimal inhibitory assay. This can deepen our understanding of the gut microbiome serving as a potential reservoir of antibiotic resistance elements which can aid in furthering the development of novel antibiotics