MICROBIAL DIVERSITY IN URBAN ENVIRONMENTS: CONCERN FOR ANTIBIOTIC RESISTANCE

We are almost oblivious to the presence of microorganisms in our daily lives, but they exist and come into contact with us all the time. While some bacteria are harmless, and even beneficial, other bacteria can cause infections. A common treatment to bacterial infections is antibiotics and the success of an antibiotic depends on the resistance of the bacteria to the antibiotic. We conducted experiments to identify the types of bacteria that can be found on surfaces or within soil environments that come into contact with a vast number of people on a daily basis and how this can affect the antibiotic resistance/susceptibility of these bacteria. By using common laboratory procedures to extract, amplify and identify DNA, we identified samples of bacteria. We also used the Biolog/Kirby-Bauer assay to test for their antibiotic resistance /susceptibility. The results obtained showed that surfaces with presumably greater contact with people had a greater diversity of bacteria and at the overall level, the bacteria of the sample population were mostly susceptible to the commonly used antibiotics which is a good news! In terms of soil texture, samples mostly represented sandy soil with significant admixtures of silt and clay and these were collected from wooded areas, parks, urban and farmlands located in Queens, Bronx and Long Island. Considering sandy soil, it was directly correlated with higher presence of bacterial growth and presumably due to the exposure of abundant oxygen level (greater aeration), its pore volume, and surface area. Preliminary geochemical investigations (trace elements and major oxide) of representative soil samples also demonstrated a geochemical anomaly with respect to enrichment and depletion of bacterial growth.