Q-228. Identification of Antibiotic Resistant Heterotrophic Bacteria from Recreational Water Samples

R. Ramirez-Ramos, E. Vazquez-Rivera, L. Lebron-Marrero, Y. Lizardi-Gerena, K. Malave-Llamas, N. M. Rodriguez-Bonano;
Univ. del Este, Sch. of Sci. and Technology, Carolina, PUERTO RICO.

Recreational activities in Puerto Rican beaches are one of the most popular attractions for its citizens and tourists. For this reason, the Government’s Environmental Quality Board is responsible for warning the public when an increase in E. coli and enterococci counts are detected. However, we believe that there is a broad diversity of antibiotic resistant heterotrophic bacteria in the water that may be the causative agents of serious illnesses in beach bathers. We design a protocol for identification and antibiotic resistance (AR) analysis of the different bacterial species isolated from 11 sites located at the west coast of Puerto Rico (PR). Four water samples were collected at chest-height for a total of 44 samples. Samples were processed using membrane filtration and mHPC agar to obtain bacterial isolates. Subsequently, each isolate was identified using Gram stain, OF glucose medium, oxidase and catalase test and the RapID ONE panel or sequencing of the 16S rRNA. Bacterial AR was investigated for ceftriaxone, ciprofloxacin, cefuroxime, tetracycline, ampicillin, chloramphenicol, erythromycin, vancomycin and trimethoprim-sulfamethoxazol. Gram stain determined that the bacterial diversity in the water included Gram (+) and Gram (-) cocci and bacilli. However, since most of the isolates are Gram (-) bacilli we decided to identify and perform the resistance screening for this group first. We were able to identify the following bacteria: Shigella sp., Proteus vulgaris, Pantoea agglomerans, Enterobacter sakazakii, E. cloaceae, E. coli and Stenotrophomonas maltophilia. Among these species, only P. vulgaris demonstrated multiple resistances. P vulgaris is resistant to: cefuroxime, tetracycline, ampicillin, erythromycin and vancomycin. Currently, this project is in progress and we will continue the identification and antibiotic screening for the Gram (-) cocci and the Gram (+) cocci and bacilli. The results obtained during our project will allow us to determine if the broad diversity of heterotrophic bacteria in our beaches is contributing to the dissemination of hard to treat infections that are impacting coastal communities in PR.