Antimicrobial resistance in zoonotic enteropathogens and commensal organisms is a threat to public health, which is compounded by the possibility that these pathogens may exchange antimicrobial resistance genes. The importance of Salmonella, Campylobacter, E.coli, and Enterococcus as carriers of antimicrobial resistance is well known, but limited work has been done to examine the relationship between this phenotypic characteristic and genotypic attributes of these organisms. The main objectives of this project are:
- To determine the role of plant size and associated transportation, holding times, and in-plant interventions on prevalence of resistance foodborne and commensal organisms.
- To determine the clonality of strains identified from different sizes of processing plants in two predominant pig producing geographic locations (North Carolina and Iowa) and sample type
- To determine the distribution and similarity of specific antimicrobial resistance genes and class-1 integrons among four important organisms, Salmonella, Campylobacter, E. coli, and Enterococcus.
Isolates were collected from processing plants in North Carolina and Iowa. Samples originated from the head meat, carcass, lairage swabs, and lymph nodes. Phenotypic characterization of antimicrobial resistance patterns was completed on 1,284 samples. Genotypic characterization by PCR, sequencing of resistance genes and class-1 integrons, and microarray was performed on selected isolates based on multidrug resistance pattern and association with other samples. The overlapping of resistance genes found within the four organisms may be the result of horizontal resistance gene transfer within the host.