Development of Proteomic Targeted Tests for Microbial Multiple Antibiotic Resistant Zoonotic Food Borne Pathogens

The widespread use of antibiotics in veterinary medicine and their past use as growth promoters has prompted the development of resistance by zoonotic food borne microbial pathogens. Recently, alternative methods of on farm biosecurity using disinfectants have also been linked with antimicrobial resistance. Mutation in innate regulatory chromosomal genes, characteristic of the multiple antibiotic resistance (Mar) phenotype, enables development of resistance to diverse antibiotics and disinfectants by changes in drug permeation and efflux by bacteria. This is also an important step in the progression of zoonotic pathogens to high level resistance, via further mutation or gene acquisition, that may challenge the efficacy of current antimicrobial treatments used in human medicine. Changes in the expression of proteins, that confer the Mar phenotype, present targets for a rapid specific test to identify such resistant bacteria arising from food production activities.
<OL> <LI> Cell envelope proteins extracted from Salmonella enterica serovar Typhimurium characteristic of the Mar phenotype will be determined using mutants in regulatory elements and by induction of protein expression following treatment with antibiotic and disinfectant.
<LI>Specific proteins will be ranked as targets for test development using their functionality and extent of increased expression. </ol>
Key deliverable: <OL> <LI> A simple test based on the expression of specific proteins will be developed for the Mar phenotype.
<LI>The test for the Mar phenotype will be validated using characterised isolates in the VLA collection.
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Policy relevance:<OL> <LI> Government and public awareness of the problems associated with the development of antibiotic resistance have prompted the implementation of intervention strategies (prohibition of certain antibiotics as growth promoters) and of alternate procedures (e.g. improved biosecurity including use of disinfectants) in food production. </ol> Surveillance for the Mar phenotype using a specific test(s) provides an early biomarker for the development of antibiotic resistance, evaluation of intervention strategies and the effect of new cleansing procedures.