The aim of this study was to investigate the prevalence of antimicrobial resistance in Escherichia coli isolated from pigs and their farmhouse environment in Korea. A total of 585 E. coli were isolated in this study during 2006 2007: 426 isolates from 492 pigs and 159 isolates from 312 farmhouse environment samples from 16 different pig farms. The most frequently observed resistance in pig fecal samples was antimicrobials such as tetracycline, streptomycin, and ampicillin. However, resistance to cephalosproins, β-lactam / β-lactam inhibitor combination, and colistin was low. We found an inverse relationship between prevalence of resistant E. coli and animal age. Resistance rate and multi-drug resistance (MDR) was greater in young pigs (piglet and nursery) than for those from adult pigs (grower-finish and sow). Resistance of E. coli from farm environment such as floor, Iron partition, and ventilation was similar with those from pig fecal samples. Farm environment contaminated with MDR bacteria might be a possible source of infections to pigs. Thus, to control and reduce the antimicrobial resistance in pigs, we must also pay attention to the environment.
Salmonellosis is one of the most common food-borne diseases in both humans and animals. The recovery of Salmonella from fecal and environmental samples by bacteriological assays takes several days. Polymerase chain reaction (PCR) has become an important technique for the rapid detection of Salmonella in a variety of samples, including feces. For rapid identification of Salmonella by PCR, 1 mL of enrichment culture was harvested after overnight incubation and DNA was extracted by heat lysis. To investigate the optimal conditions for rapid PCR detection of Salmonella, three different primer sets and three different enrichment media were used on a panel of Salmonella strains and a panel of non-Salmonella strains. The results showed that selenite cysteine enrichment broth and a primer set designed for the invA gene provided the most specific and rapid detection of Salmonella by PCR after the enrichment step.