Determination of antibiotic resistance bacteria populations in Tabriz wastewater of hospitals,influent and effluent of wastewater treatment plant and drinking water

Abstract

Background: The widespread use of antibiotics and their entry into receptor wastewater leads to an increase in antibiotic-resistant bacteria that have a negative effect on the treatment of bacterial infections. The aim of this study was to determine aerobic bacteria, phenotype and genotype their resistance to common antibiotics in hospital wastewater, wastewater and effluent from sewage treatment plants and drinking water sources downstream of the city of Tabriz in October, 2012- October, 2013. Materials and Methods: In a cross-sectional study (October, 2012- October, 2013), after sampling and isolated bacteria from hospital waste water, wastewater and effluent waste water treatment plants, and water downstream of the city of Tabriz, was measured using the techniques of microbiology, the sensitivity of standard disk diffusion technique and interpretation release area chart Kirby - Bauer in the laboratory of microbiology, Faculty of Tabriz University of Medical Sciences on the resistance genes by PCR in pure colonies in Tabriz Infectious Diseasees and Tropical Research Center. Results: The mean levels of total coliforms and fecal coliforms were diverse in hospitals wastewater cases the study between 2.9×102 MPN/100ml and 2.2×105 MPN/100ml, that number of coliforms in Sina hospital was about 10 to 100 times higher than other hospitals. Despite the final chlorination, the average total coliforms and fecal coliforms were in the effluent from municipal wastewater treatment plant respectively 40 and 70 times of permissible limit for discharge to surface water, also the amount of colonies (CFU) was higher in wastewater effluent. Total coliform and fecal coliform levels of underground water sources between 0/0 MPN/100ml and 8.1 MPN/100ml were that the water quality is considered excellent. The most frequent of bacteria isolated in hospitals of Imam Reza (AS), Ghazi and Sina were related to the Klebsiella (100%) and urban wastewater effluent and downstream groundwater Tabriz Staphylococcus (100%, 100% and 90/90%). The most percentage of bacteria resistant to antibiotics and antibiotic groups were observed relative to Citrobacter and E.coli (57%), penicillin's group (75%) and methicillin (83%) in hospital wastewater, Enterobacter, and E.coli (100%) and penicillin's group and ampicillin (73.5%), cephalexin (100%) in raw waste water, Enterobacter (66.7%), penicillin's group (73.5) and cephalexin (100%) in effluent waste water, and Serratia (8/76%) and Cephalosporin's group (5/52%) and methicillin (57%) in resources groundwater.117 Gene blaTEM, the most antibiotic resistance gene and the highest levels of antibiotic resistance genes (blaTEM, PER-1) were identified in E. coli and Serratia. Conclusion: Abuse of antibiotics and impact upon bacteria native to the aquatic environment, is reduced of thier ability in the treatment of bacterial infections. The higher concentrations and variety of antibiotics in hospital wastewater than municipal waste water, effluent waste water and water sources downstream Tabriz cause to increase transmission of antibiotic resistance factors among bacteria and accelerated multidrug resistance.