|Abstract Title:||LC-MS/MS chiral ananlysis of chloramphencicol in the environment|
|Session Choice:||Screening Enviroment Pollutants, what can the data tell us?|
|Presenter Name:||Ms Felicity Elder|
|Co-authors:||Dr Erika Castrignano|
Prof Barbara Kasprzyk-Hordern
|Company/Organisation:||University of Bath|
Abstract Information :
Antibiotic resistance has become a global health issue, with the World Health Organisation stating that 'AMR threatens the very core of modern medicine' and that the 'crisis must be managed with the upmost urgency'. In order to manage AMR not only do we need a thorough understanding of the different types of AMR but also the drivers behind their development and spread. What is becoming increasingly clear is that antibiotics are accumulating in our environment due to their extensive use in human and veterinary medicine, leading them to be classed as an emerging contaminant. This accumulation could be one of the possible drivers of antibiotic resistance that we need to understand to combat the threat of AMR.
Chloramphenicol is a broad spectrum bacteriostatic antibiotic. It was first isolated in 1947 and by 1949 due to its relatively simple chemical structure was the first antibiotic to be made solely synthetically in the enantiomerically pure form. In the UK chloramphenicol is almost solely used for the topical treatment of Otis externa or bacterial conjunctivitis, and rarely used systemically due to its toxic side effect. These toxic side effects also mean its use in food producing animals is banned. However, in 2005 the over the counter sale of topical chloramphenicol eye drops or ointment was approved in the UK leading to an increase in sales. This increase in the consumption of chloramphenicol eye drops and the uncertainty as to how they are being disposed of poses a possible driving factor for the development of chloramphenicol resistance within the population.
A chiral LC-MS/MS method has been developed and validated for the two chloramphenicol enantiomers R,R-(-)-chloramphenicol and S,S-(+)-chloramphenicol in wastewater and broth. This included the optimisation of a solid phase extraction method for sample clean up and concentration, followed by development of a LC-MS/MS method utilising an AGP chiral column coupled to a triple quadrupole mass spectrometer for the quantitative analysis of the two chloramphenicol enantiomers. This method has since been applied to quantify the two chloramphenicol isomers in wastewater and to study its degradation within laboratory microcosm studies to help further our understanding of the fate of chloramphenicol within the environment.