Clinical Microbiology: Open Access

Effects of rising temperature on the antibiotic susceptibility pattern of bacterial isolates from Pasig River tributaries, Philippines

6^th Clinical Microbiology Conference

October 20-22, 2016 Rome, Italy

Julieta Dungca, Ryan Labana, Gary Antonio Lirio, April Joy Fabella, Gabriel Tapar, Anna Margarita Ayacocho, Phillip Fua and Chris Coats

Centro Escolar University, Philippines

Posters & Accepted Abstracts: Clin Microbiol

Abstract:

While there has been a number of literatures suggesting the direct positive effects of increasing temperature on bacterial density, there has been scarcity of data, however, describing how temperature may impact the efficacy of antibiotics. In this study, the effect of rising temperatures brought about by global warming on the antibiotic susceptibility pattern of bacteria isolated from the surface water of Pasig River, Philippines was investigated. Nine bacterial isolates belonging to three families namely: Aeromonadaceae (Aeromonas sobria (3), Aeromonas veronii (1) and Aeromonas caviae (1)); Enterococcaceae (Enterococcus gallinarum (1)); and Enterobacteriaceae (Klebsiella oxytoca (2) and Citobacter sedlakii (1)) were tested for their activities against six antibiotics namely: Gentamicin (10 μg), Chloramphenicol (30 μg), Tetracyline (30 μg), Erythromycin (15 μg), Vancomycin (30 μg) and Bacitracin (10 units) using Kirby Bauer disk diffusion method at varying incubation temperature (37oC, 39oC, 42oC and 45oC). Bacterial density at the time of sampling was also determined. The mean heterotrophic plate count was estimated at 3.7029�?104 CFU/ml. All the nine bacterial isolates were found to be multiple drug resistant (MDR) (55.6% being triresistant while 44.4% being tetraresistant). It is surprising to note that all the nine isolates were able to tolerate high temperature exposure and that all of them exhibited resistance to erythromycin, vancomycin and bacitracin. Out of the nine isolates, eight (88.9%) and seven (77.8%) were sensitive to gentamicin and chloramphenicol, respectively, suggesting that these were still effective in killing these bacteria. A very high positive correlation (r=0.868, p=0.001) between antibiotics and zones of inhibition across varying temperatures was noted. These data may suggest possible beneficial effect of increasing temperature on the activity of some antibiotics against bacteria. Further, it implies that thermotolerant MDR bacterial strains have gone through the river water system which may pose potential threat to the public.

Biography :

Email: jzdungca@ceu.edu.ph