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Hain E, Adejumo H, Anger B, Orenstein J, Blaney L. Advances in antimicrobial activity analysis of fluoroquinolone, macrolide, sulfonamide, and tetracycline antibiotics for environmental applications through improved bacteria selection. J Hazard Mater 2021; 415:125686. [PMID: 34088184 DOI: 10.1016/j.jhazmat.2021.125686] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/19/2020] [Revised: 02/13/2021] [Accepted: 03/16/2021] [Indexed: 06/12/2023]
Abstract
The widespread use of antibiotics has led to their ubiquitous presence in water and wastewater and raised concerns about antimicrobial resistance. Clinical antibiotic susceptibility assays have been repurposed to measure removal of antimicrobial activity during water and wastewater treatment processes. The corresponding protocols have mainly employed growth inhibition of Escherichia coli. The present work focused on optimizing bacteria selection to improve the sensitivity of residual antimicrobial activity measurements by broth microdilution assays. Thirteen antibiotics from four classes (i.e., fluoroquinolones, macrolides, sulfonamides, tetracyclines) were investigated against three gram-negative organisms, namely E. coli, Mycoplasma microti, and Pseudomonas fluorescens. The minimum inhibitory concentration (MIC) and half-maximal inhibitory concentration (IC50) were calculated for each antibiotic-bacteria pair. P. fluorescens produces a fluorescent siderophore, pyoverdine, that was used to assess sublethal effects and further enhance the sensitivity of antimicrobial activity measurements. The optimal antibiotic-bacteria pairs were as follows: fluoroquinolone-E. coli (growth inhibition); macrolide- and sulfonamide-M. microti (growth inhibition); and, tetracycline-P. fluorescens (pyoverdine inhibition). Compared to E. coli growth inhibition, the sensitivity of antimicrobial activity analysis was improved by up to 728, 19, and 2.7 times for macrolides (tylosin), sulfonamides (sulfamethoxazole), and tetracyclines (chlortetracycline), facilitating application of these bioassays at environmentally-relevant conditions.
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Affiliation(s)
- Ethan Hain
- University of Maryland Baltimore County, Department of Chemical, Biochemical, and Environmental Engineering, 1000 Hilltop Circle, Engineering 314, Baltimore, MD 21250, USA
| | - Hollie Adejumo
- University of Maryland Baltimore County, Department of Chemical, Biochemical, and Environmental Engineering, 1000 Hilltop Circle, Engineering 314, Baltimore, MD 21250, USA; University of Michigan, Department of Civil and Environmental Engineering, 2350 Hayward Street, 2105 GG Brown Building, Ann Arbor, MI 48109-2125, USA
| | - Bridget Anger
- University of Maryland Baltimore County, Department of Chemical, Biochemical, and Environmental Engineering, 1000 Hilltop Circle, Engineering 314, Baltimore, MD 21250, USA
| | - Joseph Orenstein
- University of Maryland Baltimore County, Department of Chemical, Biochemical, and Environmental Engineering, 1000 Hilltop Circle, Engineering 314, Baltimore, MD 21250, USA
| | - Lee Blaney
- University of Maryland Baltimore County, Department of Chemical, Biochemical, and Environmental Engineering, 1000 Hilltop Circle, Engineering 314, Baltimore, MD 21250, USA.
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Snowberger S, Adejumo H, He K, Mangalgiri KP, Hopanna M, Soares AD, Blaney L. Direct Photolysis of Fluoroquinolone Antibiotics at 253.7 nm: Specific Reaction Kinetics and Formation of Equally Potent Fluoroquinolone Antibiotics. Environ Sci Technol 2016; 50:9533-42. [PMID: 27479003 DOI: 10.1021/acs.est.6b01794] [Citation(s) in RCA: 34] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/12/2023]
Abstract
Three fluoroquinolone-to-fluoroquinolone antibiotic transformations were monitored during UV-C irradiation processes. In particular, the following reactions were observed: enrofloxacin-to-ciprofloxacin, difloxacin-to-sarafloxacin, and pefloxacin-to-norfloxacin. The apparent molar absorptivity and fluence-based pseudo-first-order rate constants for transformation of the six fluoroquinolones by direct photolysis at 253.7 nm were determined for the pH 2-12 range. These parameters were deconvoluted to calculate specific molar absorptivity and fluence-based rate constants for cationic, zwitterionic, and anionic fluoroquinolone species. For a typical disinfection fluence of 40 mJ/cm(2), the apparent transformation efficiencies were inflated by 2-8% when fluoroquinolone products were not considered; moreover, the overall transformation efficiencies at 400 mJ/cm(2) varied by up to 40% depending on pH. The three product antibiotics, namely ciprofloxacin, sarafloxacin, and norfloxacin, were found to be equally or more potent than the parent fluoroquinolones using an Escherichia coli-based assay. UV treatment of a solution containing difloxacin was found to increase antimicrobial activity due to formation of sarafloxacin. These results highlight the importance of considering antibiotic-to-antibiotic transformations in UV-based processes.
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Affiliation(s)
- Sebastian Snowberger
- University of Maryland Baltimore County , Department of Chemical, Biochemical and Environmental Engineering, 1000 Hilltop Circle, ECS 314 Baltimore, Maryland 21250, United States
| | - Hollie Adejumo
- University of Maryland Baltimore County , Department of Chemical, Biochemical and Environmental Engineering, 1000 Hilltop Circle, ECS 314 Baltimore, Maryland 21250, United States
| | - Ke He
- University of Maryland Baltimore County , Department of Chemical, Biochemical and Environmental Engineering, 1000 Hilltop Circle, ECS 314 Baltimore, Maryland 21250, United States
| | - Kiranmayi P Mangalgiri
- University of Maryland Baltimore County , Department of Chemical, Biochemical and Environmental Engineering, 1000 Hilltop Circle, ECS 314 Baltimore, Maryland 21250, United States
| | - Mamatha Hopanna
- University of Maryland Baltimore County , Department of Chemical, Biochemical and Environmental Engineering, 1000 Hilltop Circle, ECS 314 Baltimore, Maryland 21250, United States
| | - Ana Dulce Soares
- University of Maryland Baltimore County , Department of Chemical, Biochemical and Environmental Engineering, 1000 Hilltop Circle, ECS 314 Baltimore, Maryland 21250, United States
| | - Lee Blaney
- University of Maryland Baltimore County , Department of Chemical, Biochemical and Environmental Engineering, 1000 Hilltop Circle, ECS 314 Baltimore, Maryland 21250, United States
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