New Mexico Geological Society Annual Spring Meeting — Abstracts

The ability to produce antibiotics, which reduce the reproduction rate of other competitors, is an evolutionary mechanism that some bacteria exhibit in order to survive. Organic material rarely enters caves in the desert due to low rainfall, resulting in a deficiency of nutrients inside the cave. Bacteria in caves live under stressful conditions and constantly are competing; therefore, bacteria found in caves are likely to produce antibiotics. This study was conducted to assay bacteria in Parks Ranch Cave, Eddy County, New Mexico, for antibiotic-producing characteristics and to identify the bacteria.

The samples were cultured at sites inside the cave. The bacterial colonies from the cave were tested for antibiotic-producing characteristics against Escherichia coli and Staphylococcus saprophyticus. The colonies were also identified using identification flow charts. Bacteria in Parks Ranch Cave did not have the antibiotic-producing characteristics for the cultures against which they were tested. Pseudomonas fluorescens has been shown in other studies to produce antibiotics. Pseudomonas aeruginosa is a pathogenic bacterium that targets immuno-compromised individuals. These two Pseudomonas species were found at the same site, indicating that some species may still be competing for nutritional sources.