Prevalence and characterisation of bacterial antibiotic resistance within the porcine intestinal tract

• Main Author: Blake, Damer Peter
• Published: University of Aberdeen 2002
• Subjects: 636; Veterinary sciences & veterinary medicine
• Online Access: http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.248653

Within the pig population of Northeast Scotland resistance to tetracycline and ampicillin was found to be widespread among commensal <I>Escherichia coli, </I>as also noted among anaerobic commensals of the genera <I>Bacteroides </I>and <I>Lactobacillus. E. coli </I>resistant to apramycin and nalidixic acid and enterococci resistant to vancomycin were less frequently isolated but remained common. Production system, piglet age and recent transportation were found to influence the antibiotic resistant proportion of the faecal <I>E. coli </I>population whilst dietary copper inclusion did not. Within the intestinal tract higher proportions of resistance to ampicillin were noted among the <I>E. coli </I>of the ileum and caecum than more distal sections and to apramycin and nalidixic acid among the ileal mucosal associated <I>E. coli </I>than those of the ileal lumen. Novel techniques for characterising and modelling antibiotic resistant bacterial populations were suggested and investigated. A spiral-plater system was used to investigate the phenotypic expression of antibiotic resistance among faecal <I>E. coli, </I>complemented by the development of a PCR technique to identify the genetic basis of tetracycline resistance. The effects of antimicrobial supplementation on the indigenous enteric flora were monitored through the validation and use of an <I>in vitro </I>porcine ileal simulation. Within the same model transmission of genetic material encoding antibiotic resistance was demonstrated between commensal and pathogenic representatives of the <I>Enterobacteriaceae </I>under ileal conditions. Variation in the mucosal adherence of <I>E. coli </I>expressing different antibiotic resistant attributes was investigated <I>in vitro </I>following the implementation of a modified cell culture technique.