Abstract: Hidden Treasure Lies Beneath the Earth's Surface: Do Nutrient Availability and Human Impact Correlate to Antibiotic Production in Cave Bacteria? (2011 SACNAS National Conference)

Friday, October 28, 2011

Hall 1-2 (San Jose Convention Center)

Lory Henderson, BS , Biology, University of New Mexico, Albuquerque, NM

Martha Jo Vargas , Biology, University of New Mexico, Albuquerque, NM

Jessica Snider , Biology, University of New Mexico, Albuquerque, NM

Samantha Bear , Biology, University of New Mexico, Albuquerque, NM

Patty Murray , Biology, University of New Mexico, Albuquerque, NM

Maria De Lurdes Nunes Enes Dapkevicius, PhD , Dept. of Agricultural Science , University of the Azores , Ponta Delgada, São Miguel, Azores, Portugal

Diana E. Northup, PhD , Biology Dept, University of New Mexico, Albuquerque, NM

Experiments on the microbial diversity in caves led to the discovery of novel species of bacteria that are isolated underground in a nutrient-limited environment. Actinobacteria, the most prolific group of antibiotic-producing bacteria, are widespread in caves; preliminary studies have shown that some of these Actinobacteria produce antibiotics. The goal of this study is to determine the effects of human visitation and nutrient availability on the occurrence of antibiotic-producing bacteria in New Mexico carbonate cave environments. We test these effects by sampling from four high or low visitation carbonate caves in Carlsbad Caverns National Park and Fort Stanton Cave. We hypothesize that increased human visitation and increased nutrient availability will decrease the occurrence of antibiotic-producing bacteria due to rising temperature and decreased competition, respectively. Soil samples are analyzed for carbon and nitrogen content to determine the effect of nutrient availability on the production of antibiotics. Bacterial cultures were inoculated on two different media, R2A and ½ R2A supplemented with pulverized carbonate rock dust. After sub-culturing to obtain pure cultures, bacteria are tested for antibiotic production using an agar diffusion test using pathogenic bacterica (Staphylococcus aureus, Pseudomonas aeruginosa, Klebsiella pneumoniae, Proteus vulgaris, Shigella flexneri, Streptococcus pyogenes, Streptococcus agalactiae, and Streptococcus pneumoniae). Antibiotic production in cave bacteria was correlated with the level of nutrients and the level of cave visitation. Understanding the ecological conditions under which bacteria produce antibiotics will allow for more successful identification and isolation of novel antibiotic-producing bacteria, ultimately leading to new antibiotics to which bacteria are not yet resistant.