Validation of a modified IDEXX defined-substrate assay for detection of antimicrobial resistant in environmental reservoirs.

The emergence of antimicrobial resistant (AMR) bacteria has been identified as one of the principal public health threats of the 21st century. The World Health Organization (WHO) has long recognized the threat of AMR bacteria and highlights environmental surveillance as a key step in understanding and combating the global rise of antimicrobial resistance. Here, we modified and validated an IDEXX defined-substrate assay commonly used for recreational water quality monitoring of to enumerate cefotaxime resistant in environmental reservoirs.

Molar absorption coefficients and acid dissociation constants for fluoroquinolone, sulfonamide, and tetracycline antibiotics of environmental concern.

Antibiotics are priority contaminants of emerging concern due to their pseudo-persistence in the environment and contribution to the development of antimicrobial resistance. In solution, antibiotics undergo (de)protonation reactions that affect their UV absorbance and, therefore, photolytic fate in natural and engineered systems. This study employed enhanced spectrophotometric methods to determine the acid dissociation constants (as pK values) and molar absorption coefficients for 12 fluoroquinolone, 9 sulfonamide, and 7 tetracycline antibiotics of environmental relevance.