@article{dutta_altermann_crespo_olson_siletzky_kathariou_2017, title={Identification of a Campylobacter coli methyltransferase targeting adenines at GATC sites}, volume={364}, DOI={10.1093/femsle/fnw268}, abstractNote={Abstract Campylobacter coli can infect humans and colonize multiple other animals, but its host‐associated genes or adaptations are poorly understood. Adenine methylation at GATC sites, resulting in MboI resistance of genomic DNA, was earlier frequently detected among C. coli from swine but not among turkey‐derived isolates. The underlying genetic basis has remained unknown. Comparative genome sequence analyses of C. coli 6461, a swine‐derived strain with MboI‐resistant DNA, revealed two chromosomal ORFs, 0059 and 0060, encoding a putative DNA methyltransferase and a conserved hypothetical protein, respectively, which were lacking from the genome of the turkey‐derived C. coli strain 11601, which had MboI‐susceptible DNA. To determine whether ORF0059 mediated MboI resistance and hence encoded a putative N6‐adenine DNA methyltransferase, the gene was cloned immediately upstream of a chloramphenicol resistance cassette (cat) and a PCR fragment harboring ORF0059‐cat was transformed into C. coli 11601. The transformants had MboI‐resistant DNA, suggesting a direct role of this gene in methylation of adenines at GATC sites. In silico analyses suggested that the ORF0059‐ORF0060 cassette was more frequent among C. coli from swine than certain other sources (e.g. cattle, humans). Potential impacts of ORF0059‐mediated methylation on C. coli host preference and other adaptations remain to be elucidated.}, number={7}, journal={FEMS Microbiology Letters}, author={Dutta, V. and Altermann, E. and Crespo, M. D. and Olson, J. W. and Siletzky, R. M. and Kathariou, S.}, year={2017} }
 @article{crespo_altermann_olson_miller_chandrashekhar_kathariou_2016, title={Novel plasmid conferring kanamycin and tetracycline resistance in the turkey-derived Campylobacter jejuni strain 11601MD}, volume={86}, ISSN={["1095-9890"]}, DOI={10.1016/j.plasmid.2016.06.001}, abstractNote={In Campylobacter spp., resistance to the antimicrobials kanamycin and tetracycline is frequently associated with plasmid-borne genes. However, relatively few plasmids of Campylobacter jejuni have been fully characterized to date. A novel plasmid (p11601MD; 44,095 nt) harboring tet(O) was identified in C. jejuni strain 11601MD, which was isolated from the jejunum of a turkey produced conventionally in North Carolina. Analysis of the p11601MD sequence revealed the presence of a high-GC content cassette with four genes that included tet(O) and a putative aminoglycoside transferase gene (aphA-3) highly similar to kanamycin resistance determinants. Several genes putatively involved in conjugative transfer were also identified on the plasmid. These findings will contribute to a better understanding of the distribution of potentially self-mobilizing plasmids harboring antibiotic resistance determinants in Campylobacter spp. from turkeys and other sources.}, journal={PLASMID}, author={Crespo, M. D. and Altermann, E. and Olson, J. and Miller, W. G. and Chandrashekhar, K. and Kathariou, S.}, year={2016}, month={Jul}, pages={32–37} }
 @article{crespo_kathariou_grimes_cox_buhr_frye_miller_jackson_smith_2016, title={Routes of transmission of Salmonella and Campylobacter in breeder turkeys}, volume={25}, ISSN={["1537-0437"]}, DOI={10.3382/japr/pfw035}, abstractNote={Abstract Salmonella and Campylobacter are frequent colonizers of the intestinal tracts of poultry and have often been associated with human foodborne illness. The entry, transmission, and prevalence of both pathogens have been extensively studied in chickens but little information is available for turkeys. This project monitored turkey breeder hens and toms from d of hatch to 65 wk of age with the objective of determining routes of transmission for Salmonella and Campylobacter throughout the turkey production cycle. Breeder poults were separated by sex and then into 2 groups (control and inoculated) for each sex. The inoculated group was orally gavaged with marker strains of both Salmonella and Campylobacter. The inoculated groups (toms and hens) were placed on the opposite side of a growout house from the uninoculated groups. Fecal samples, intestinal samples and organs, feed, drinkers, and potential vectors such as insects and mice, were analyzed at different times until 65 wk. Monitoring showed that Campylobacter spread rapidly and cross-contaminated turkeys throughout the growout house. For both Salmonella and Campylobacter, naturally occurring strains that were first isolated in control groups at wk 3 and 4, respectively, outcompeted marker strains several wk post inoculation and persisted in the flock. The most common naturally occurring strains were C. jejuni (tetracycline resistant), C. coli (kanamycin resistant), and S. Agona. Campylobacter and Salmonella also were isolated from flies and from a mouse, confirming the importance of proper pest control and biosecurity to reduce the spread of the bacteria.}, number={4}, journal={JOURNAL OF APPLIED POULTRY RESEARCH}, author={Crespo, M. D. and Kathariou, S. and Grimes, J. L. and Cox, N. A. and Buhr, R. J. and Frye, J. G. and Miller, W. G. and Jackson, C. R. and Smith, D. P.}, year={2016}, month={Dec}, pages={591–609} }
 @article{crespo_olson_altermann_siletzky_kathariou_2012, title={Chromosomal tet(O)-Harboring Regions in Campylobacter coli Isolates from Turkeys and Swine}, volume={78}, ISSN={["0099-2240"]}, DOI={10.1128/aem.02258-12}, abstractNote={ABSTRACT}, number={23}, journal={APPLIED AND ENVIRONMENTAL MICROBIOLOGY}, author={Crespo, M. D. and Olson, J. W. and Altermann, E. and Siletzky, R. M. and Kathariou, S.}, year={2012}, month={Dec}, pages={8488–8491} }