Antibiotic Resistance Profile and Chemical Quality Assessment of Groundwater Sources from Periurban Area of Bucharest, Romania
Twenty-two groundwater sources mainly used for drinking purpose in Bucharest peri-urban area were investigated for assessment of physico-chemical and microbiological quality with a view to determining its potential risk to public health. Results of chemical analysis revealed that nitrites, sulphates and chlorides were below the permissible levels, while 63.64% of the analysed groundwater sources exceeded the maximum admissible concentration for nitrates, with concentration variations ranging from 67.27 to 523.19 mg/L. The bacteriological analysis showed that in about 63% of groundwater sources total coliform, faecal coliform and enterococci have exceeded the threshold limits recommended by the Drinking Water Directive 98/83/EC and the Romanian Law. Another aim of the study was to investigate the prevalence of antibiotic resistance among Gram-negative strains isolated from groundwater sources. There observed the resistance to many antibiotics, particularly: ticarcillin (80%), aztreonam (29%), gentamicin (11%), imipenem (9%), ceftriaxone (9%), ceftazidime (3%) and ciprofloxacin (3%). Significant higher resistance rates were observed in strains isolated from shallow groundwater sources as compared with strains isolated from deep groundwater sources. Pseudomonas sp. (26%) isolates with multiple-drug resistance (MDR) were encountered. The results of the study revealed a bacteriological contamination and high levels of nitrate concentrations in most of the groundwater samples, which could pose an important risk to human health. Keywords: bacterial resistance, groundwater, antibiotics, nitrate, waterborne diseases