|Miller, William - Bill|
Submitted to: Applied and Environmental Microbiology
Publication Type: Peer reviewed journal
Publication Acceptance Date: 1/27/2007
Publication Date: 4/1/2007
Citation: D'Lima, C., Miller, 2007 W.G., Mandrell, R.E., Wright, S.L., Siletsky, R., Carver, D.K., Kathariou, S. Clonal Population Structure and Specific Genotypes of Multi-drug Resistant Campylobacter coli from Turkeys.. Applied and Environmental Microbiology. 73(7) 2156-2164 Interpretive Summary: Turkey flocks are colonized often with strains of the human pathogen Campylobacter coli that are resistant to multiple antibiotics (such as tetracycline and streptomycin). These strains have been designated multidrug resistant (MDR). We describe here the characterization of 59 MDR strains from turkeys. These turkey strains were characterized by three methods: DNA fragment based-pulsed field gel electrophoresis (PFGE) and DNA sequence based-multilocus sequence typing and fla typing. There was correspondence in the strain types identified with all three methods. However, very few types were identified indicating that the MDR strains are highly related. The correspondence between the typing methods indicates that such methods can be used to rapidly distinguish MDR strains in a population of C. coli.
Technical Abstract: Commercial turkey flocks in eastern North Carolina have been found to be colonized frequently with Campylobacter coli strains that are resistant to several antimicrobials (tetracycline, streptomycin, erythromycin, kanamycin, and ciprofloxacin/nalidixic acid); such strains have been designated multidrug resistant (MDR). However, the population structure of MDR C. coli from turkeys remains poorly characterized. In this study, analysis of multilocus sequence typing (MLST)-based sequence types (STs) of 59 MDR strains from turkeys revealed that the majority of these strains had a relatively small number of different STs, with three STs accounting for 41 (69%) of the strains. The major STs were turkey-specific, and strains with these STs were mostly resistant to the panel of antibiotics mentioned above, or, in some cases, susceptible to just one or two of the antibiotics in this panel. Further subtyping using fla typing and pulsed field gel electrophoresis (PFGE) with SmaI and KpnI revealed that each of the major MDR STs contained strains of related, but distinct subtypes, providing evidence for genomic diversification within these STs. These findings suggest that MDR strains of C. coli from turkeys have a clonal population structure characterized by the presence of a relatively small number of clonal groups that appear to be disseminated in the turkey production system. In addition, the observed correlation between STs and the MDR profiles of the organisms indicates that MLST-based typing holds potential for source-tracking applications specific to the animal source (turkeys) and the antimicrobial resistance profile (MDR status) of C. coli.