Resistance to Aminoglycosides in Klebsiella pneumoniae from Environmental Waters

The growing number of antibiotic resistance from bacterial pathogens is troubling when treating infectious diseases. Klebsiella pneumoniae is a gram-negative, lactose fermenting bacteria that in the clinic can cause urinary tract infections, as well as lower biliary tract, and surgical wound infections. Klebsiella is reported to cause 8% of all nosocomial infections in the United States and Europe. For this reason it is important to study K. pneumoniae in the environment and evaluate their resistance to understand the origin of resistance in the clinic. Specifically, the resistance to aminoglycosides an antibiotic class that binds to the A site of the 30s ribosomal subunit and causes mistranslation of mRNA producing nonfunctional proteins, that essentially halt bacterial growth. The objective of this study was to characterize the resistance profile of  K. pneumoniae to aminoglycosides from environmental sites. Water samples were taken from creeks and from beaches in Orange County, California and were then grown on selective media. We then used Matrix Assisted Laser Desorption Ionization Time-of-Flight (MALDI-T1OF) mass spectrometry to identify the bacteria. An antimicrobial disk susceptibility test was then performed to determine the different resistance profiles of each isolate according to Clinical and Laboratory Standards Institute (CLSI) guidelines.14 of 37 (38%) K. pneumoniae tested were resistant to Gentamicin and Streptomycin, while only 1 of 37 (3%) K. pneumoniae tested were resistant to Spectinomycin. A large majority of resistance was found against Gentamicin and Spectinomycin, followed by Kanamycin, Tobramycin, and Neomycin, and finally Spectinomycin had the least amount of resistance. Currently Polymerase Chain Reaction (PCR) is being performed on the environmental samples we found, which we can then use to identify which genes are conferring resistance to these antibiotics. As well as observe if these genes are also present in other types of bacteria, and if they are found in other types of environments.