Open AccessNatural Transformation-Mediated Transfer of Erythromycin Resistance in Campylobacter coli Strains from Turkeys and Swine
Author(s) -
Joo-Sung Kim,
Donna K. Carver,
Sophia Kathariou
Publication year - 2006
Publication title -
applied and environmental microbiology
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.552
H-Index - 324
eISSN - 1070-6291
pISSN - 0099-2240
DOI - 10.1128/aem.72.2.1316-1321.2006
Subject(s) - campylobacter , erythromycin , transformation (genetics) , microbiology and biotechnology , biology , resistance (ecology) , bacteria , antibiotics , genetics , ecology , gene
Erythromycin resistance inCampylobacter coli from meat animals is frequently encountered and could represent a substantial barrier to antibiotic treatment of human infections. Erythromycin resistance in this organism has been associated with a point mutation (A2075G) in the 23S rRNA gene. However, the mechanisms responsible for possible dissemination of erythromycin resistance inC. coli remain poorly understood. In this study, we investigated transformation-mediated acquisition of erythromycin resistance by genotypically diverseC. coli strains from turkeys and swine, with total genomic DNA from erythromycin-resistantC. coli of either turkey or swine origin used as a donor. Overall, transformation to erythromycin resistance was significantly more frequent inC. coli strains from turkeys than in swine-derived strains (P < 0.01). The frequency of transformation to erythromycin resistance was 10−5 to 10−6 for turkey-derived strains but 10−7 or less forC. coli from swine. Transformants harbored the point mutation A2075G in the 23S rRNA gene, as did the erythromycin-resistant strains used as DNA donors. Erythromycin resistance was stable in transformants following serial transfers in the absence of the antibiotic, and most transformants had high MICs (>256 μg/ml), as did theC. coli donor strains. In contrast to the results obtained with transformation, spontaneous mutants had relatively low erythromycin MICs (32 to 64 μg/ml) and lacked the A2075G mutation in the 23S rRNA gene. These findings suggest that natural transformation has the potential to contribute to the dissemination of high-level resistance to erythromycin amongC. coli strains colonizing meat animals.