Antibiotic Resistance of Enterobacteria present in an Urban Wastewater Treatment Plants: A Public Health Problem

Abstract

Background: Bacterial resistance to multiple antibiotics is considered one of the most important public health problems in Latin America. In Ecuador, there is a high rate of infectious diseases caused by Enterobacteriaceae which mainly affect the central nervous system, digestive and urinary tract, respiratory system, bloodstream, etc. This type of infections affects children, young people and adults with no effective treatments due to the resistance to even fifth-generation antibiotics. Inadequate procedures for handling and disposal of solid and liquid waste are another cause for the generation of this resistance and its consequences on population health. Urban wastewater treatment plants represent important reservoirs of human and animal commensal bacteria. Objective: The objective of this study was determinate the resistance of Enterobacteria isolated from septic tanks of the Domestic Wastewater Treatment Plant against different commercial antibiotics. Methodology: With 10 g of residual sludge by the serial dilution method in MacConkey and EMB culture media, isolations of several Enterobacteria were obtained, then, isolates were characterized and subjected to resistance tests using disks of three different antibiotics that are frequently used in infectious treatments caused by Enterobacteria. Results: Sixteen cultures with different morphology were obtained and described as common species genera within the Enterobacteriaceae: Escherichia, Salmonella, Proteus, Klebsiella, Shigella, Enterobacter. Strain 2872 was discarded due to its similar morpho-physiology to 2867. Thirteen of fifteen strains have tetracycline resistance and only two were inhibited (2873 and 2876); only one of the fifteen were resistant to polymyxin B (2870) and eight were resistant to cefepime. Conclusion: Only polymyxin B could be used for treatment of infections occurred by some of these isolated strains, although its use should be limited due to negative effects related to nephrotoxic and neurotoxic potential.