Abstract:
Wide spread occurrence of antibiotics and antibiotic resistant bacteria in environmental matrices is posing a serious threat to public health worldwide. Since the significance of bacterial isolates from environmental samples as a reservoir of antibiotic resistance is not well documented in Pakistan, therefore the aim of present study was to isolate and characterize bacterial strains from wastewater channels in vicinity of pharmaceutical industries and hospitals of Islamabad, Rawalpindi and Faisalabad, to inspect the presence of antibiotic resistant microorganisms. Antibiotic susceptibility of one hundred nine isolated strains was tested according to the Kirby–Bauer disc diffusion method against five most commonly used antibiotics. Results of this study indicated that amongst all tested antibiotics, Ampicillin and Levofloxacin resistance had the highest and lowest frequency, respectively. The resistance pattern observed was; Ampicillin (92.0%)> Amoxicillin (83.5%) > Ofloxacin (67.0%) > Ciprofloxacin (28.0%) > Levofloxacin (21.1%). Out of the tested strains, 30.3% showed resistance to more than three drugs. Among frequently isolated species, maximum resistance was observed in species from the genus Escherichia (57.1%), Aeromonas (56.3%), Acinetobacter (41.2%), Shewanella (25.0%), Proteus (14.0%) and Pseudomonas (8.3%) while among the less frequently isolated strains Citrobacter sp., Comamonas sp., Bacillus sp. and Alishewanella sp. showed 100% resistance to all the tested antibiotics. Incidence of Ciprofloxacin resistance in Acinetobacter sp., Escherichia sp. and Aeromonas sp. was higher than that of Levofloxacin resistance, while a large number of isolates showed intermediate resistance to Levofloxacin. The results of present study confirm presence of multidrug resistant isolates in wastewater streams of Pakistan which may lead to the proliferation of antibiotic resistance in pathogens and ultimately becoming the reason of treatment failures.
