scholarly journals Antibiotic resistant bacteria in an urban freshwater ecosystem in central Texas

Fine Focus ◽  
2017 ◽  
Vol 3 (2) ◽  
pp. 113-126
Author(s):  
Annie Kwok ◽  
Michael C. Davis ◽  
Sanghoon Kang

Antibiotic resistance is a growing concern for the human population and is becoming prevalent in many environments. For example, increasing occurrences of antibiotic resistance genes (ARGs) in aquatic ecosystems elevates the risk of pathogenic microbes acquiring those resistance genes. There is an urgent need to more closely examine the relationship between antibiotic resistant bacteria (ARB) and antibiotic residues in urban freshwater environments. Thus, our main objective was to investigate the presence of antibiotic resistance in wastewater treatment plant (WWTP) influent and effluent leading into the Brazos River using several commonly used antibiotics: penicillin, ciprofloxacin, erythromycin, trimethoprim, tetracycline, sulfamethoxazole, and gentamicin. An additional aim was to explore possible mechanisms of resistance emergence to these antibiotics using techniques such as replica plating, the Luria-Delbrück Fluctuation Test, the Newcombe Test, and 16S rRNA sequencing. Four samples of influent and treated effluent wastewater were collected from the WWTP to enumerate resistant bacteria in the community and to investigate whether mutations causing resistance in ARB might be induced or spontaneous. We found that penicillin had the highest rate of resistance in all samples and that a similar trend of resistance appeared across all four samples. According to the Luria–Delbrück Fluctuation Test and the Newcombe Test, different antibiotics appear to be associated with different tendencies of resistance emergence, with certain groups of antibiotics producing different results, which raises evolutionary questions about the roles of random mutation and induction. Most ARB detected from the Luria–Delbrück Fluctuation Test belong to the Klebsiella, Enterobacter, and Aeromonas genera. This study provides a baseline understanding of the urban freshwater ecosystem status in central Texas and quantitatively examines the degree of resistance emergence.

2010 ◽  
Vol 56 (7) ◽  
pp. 558-568
Author(s):  
George J. Sorger ◽  
James S. Quinn

Sewage, a major source of bacterial contamination of the environment, can be an important health hazard. The presence of antibiotic-resistant bacteria in sewage can exacerbate this problem. The sources of antibiotic-resistant bacteria in sewage are, for this reason, worth identifying and addressing. The bacterial flora in the effluent of the Woodward Avenue Wastewater Treatment Plant (WAWTP) in Hamilton, Ontario, Canada, contains many antibiotic-resistant coliforms. Here we ask, are the antibiotic resistance genes in the coliforms in the effluent of WAWTP descended from a recent common ancestor strain? If so, the source could be identified and eliminated. If, on the other hand, the antibiotic resistance genes in the bacterial flora of the WAWTP have more than one origin, identification and elimination of the source(s) could be difficult. There was considerable diversity of antibiotic resistance patterns and antibiotic resistance genes among the effluent and influent coliform isolates of the WAWTP, suggesting multiple genetic ancestry. The patterns of horizontal transmissibility and sequence differences in the genes tetA and tetE among these coliform isolates also suggest that they have no one predominant ancestral strain. Using the same logic, the evidence presented here is not compatible with a single ancestral origin of the antibiotic resistance genes in the isolates described herein.


2021 ◽  
Vol 26 ◽  
Author(s):  
Maria Camila Zapata Zúñiga ◽  
Miguel Angel Parra-Pérez ◽  
Johan Alexander Álvarez-Berrio ◽  
Nidia Isabel Molina-Gómez

This study aimed to evaluate the efficiency of technologies for removing antibiotics, antibiotic-resistant bacteria and their antibiotic resistance genes, and the countries where they have been developed. For this purpose, was conducted a systematic review to identify the tertiary treatments to remove the above-mentioned pollutants. The ScienceDirect and Scopus databases were used as sources of information, taking into account only experimental research from 2006 to 2019 and technologies with removal rates higher than 70% to the information analyses. From the analysis of 9 technologies evaluated, in a set of 47 investigations, photo-Fenton, and electrochemical treatments were found to be the most efficient in the removal of antibiotics; gamma radiation and photocatalysis with TiO2 and UV revealed better results in the removal of resistant microbial agents and their resistance genes, with efficiencies of 99.9%. As one of the largest producers and consumers of antibiotics, China appears to be the country with the most scientific research on the area. The importance of innovation in wastewater treatment processes to achieve better results in the remotion of antibiotics, antibiotic-resistant bacteria, and their resistance genes is highlighted, given the effects on the aquatic ecosystems and public health.


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