MOLECULAR APPROACHES FOR THE IDENTIFICATION AND CHARACTERIZATION OF ANTIMICROBIAL RESISTANCE IN FOODBORNE PATHOGENS
Location: Bacterial Epidemiology and Antimicrobial Resistance
Project Number: 6612-32000-006-00
Start Date: Nov 03, 2011
End Date: Nov 02, 2016
1. Identify and characterize potential genetic markers within and across genera of the high priority foodborne organisms for poultry attribution. With current priorities, the organisms should include Salmonella and Campylobacter.
2. Determine unique characteristics of high priority serotypes of antimicrobial–resistant foodborne bacteria and those of highly resistant or multi-resistant genotypes with novel phenotypes.
3. Evaluate the role of innovative chemical and/or biological treatments, such as arsenicals, prebiotics, or ammonium compounds and how they affect the prevalence and type of resistant pathogens or resistance genes.
In the previous project plan, studies were initiated in order to provide a basic understanding of the development, prevalence, dissemination, and persistence of antimicrobial resistance. Molecular methods were developed for rapid identification of bacterial species and antimicrobial resistance genes. The goal of the proposed project plan is to characterize antimicrobial resistant foodborne pathogens and commensals from the extensive National Antimicrobial Resistance Monitoring System (NARMS) bacterial culture collection and other foodborne bacterial culture collections using molecular tools.
For Objective 1, genomic sequencing will be performed initially on bacterial isolates from the NARMS program to identify potential genes which can be used as genetic markers. Genetic markers will differentiate bacteria from poultry from the other major food animal sources. This information is critical for tracing bacterial sources in foodborne outbreaks or contamination of environmental areas.
For Objective 2, unique characteristics of high priority serotypes or subtypes of antimicrobial–resistant foodborne bacteria will be examined in detail using genomic sequencing, microarray analysis, and PCR. Isolates that exhibit high levels of resistance, multi-drug resistant genotypes or novel phenotypes will be given priority. Vehicles for the dissemination of resistance genes (e.g. plasmids, transposons, and integrons) will be given special focus. We will detect new or emerging antimicrobial resistance in foodborne bacteria which is essential for understanding development of antimicrobial resistance.
In Objective 3, target bacterial populations identified from the above objectives will be tested for resistance to non-antimicrobial chemicals or solutions (biocides) commonly used in poultry or poultry processing. Resistance levels of isolates will be assessed followed by genetic analysis of the genes encoding the resistance. This will include bacterial conjugation to determine if the genes may be transferred within and between bacteria as well as cloning and characterization of the resistance genes. These validation studies will provide important data on resistance to commercially based non-antimicrobials in poultry processing.