The effect of environmental factors on the abundance of cefotaxime-resistant Escherichia coli in Sunter River

The water quality of the Sunter River in Jakarta was classified as heavily polluted due to activities around the river, both domestic and non-domestic. As one of the environmental parameters for water quality, the presence of Escherichia coli (E. coli) is normally found any natural environment, and under certain conditions it can become resistant to antimicrobials due to genetic mutations. The mutated E. coli produces Extended Spectrum Beta-Lactamase (ESBL) enzymes and has a higher survival ability in antibiotic-contaminated river water, thus potentially endangering public health. This study was aimed to evaluate the effect of environmental factors on the abundance of ESBL producing E. coli and their resistance to antibiotic cefotaxime. Sampling was conducted in six locations representing the upstreams and the downstreams of Sunter River, following the Global Surveillance guidelines. E. coli strains were isolated using Tryptone Bile X-glucuronide (TBX) agar medium (with and without the addition of cefotaxime 4μg/ml) and the antibiotic sensitivity test of ESBL E. coli was conducted by performing a double-disk test. The results showed that the highest average abundance of ESBL E. coli was found in the sample taken from Sindang Station (904.24 x 10⁴ colony per unit (CFU) / 100 mL) and the lowest was from Sunter Station (1,58 x 10⁴ CFU / 100 mL). The results of the Bivariate Pearson correlation analysis showed that temperature, pH, and salinity were negatively correlated with the abundance of ESBL-producing E. coli bacteria.