Campylobacter coliOutbreak in Men Who Have Sex with Men, Quebec, Canada, 2010–2011

During September 2010-November 2011, a cluster of erythromycin-susceptible, tetracycline-and ciprofloxacinresistant Campylobacter coli pulsovar 1 infections was documented, involving 10 case-patients, in Montreal, Quebec, Canada.The findings suggested sexual transmission of an enteric infection among men who have sex with men.C ampylobacter coli is the second most common species that causes human Campylobacter infections (1-3).Few studies have characterized the differences between the epidemiology and the disease of C. coli infections in comparison to C. jejuni subsp.jejuni infections (1-3).However, many studies have reported a higher macrolide resistance in C. coli than in C. jejuni (1-3).Few C. coli outbreaks have been reported to date (4,5). The StudyA retrospective analysis, including the period from January 1, 2010 through December 31, 2011, identified 43 laboratory-confirmed cases of C. coli infections reported to the Montreal Public Health Department; among them, 40 cases with antimicrobial drug susceptibility results were further analyzed.Telephone interviews with the case-patients were conducted by using a standardized questionnaire pertaining to symptomatology of the illness, treatment, exposures, sexual orientation (including practices), and HIV status.The questionnaire was mailed to persons who could not be contacted by phone.Hospital charts for 9 or the 10 outbreak case-patients were reviewed retrospectively.Statistical analyses, using Fisher exact test to calculate the possibilities, were conducted to test for differences in characteristics between case-patients infected with the outbreak etiologic agent, C. coli pulsovar 1, and those infected with nonoutbreak C. coli.In estimating the odds ratio from a 2 × 2 table that included a zero cell, 0.5 was added to the count in each cell.CIs were calculated by using Miettinen's test-based method.Statistical analyses were conducted using SPSS software (http://www-01.ibm.com/software/analytics/spss/products/statistics/).Phenotypic identification of Campylobacter isolates at the genus and species levels was confirmed by cpn60 gene sequencing at Laboratoire de Santé Publique du Québec.C. coli strains were identified by direct sequencing of PCRamplified partial cpn60 sequences as described by Hill et al. (6).DNA sequences were determined with an ABI 3100 sequencer using a BigDye sequencing kit (Applied Biosystems, Foster City, CA, USA).The sequences were subjected to a BLAST analysis and aligned with the ClustalW program.Phylogenetic analysis was performed using the Lasergene software V6.1 (DNAstar, Madison, WI, USA).Genetic relatedness was investigated by using pulsed-field gel electrophoresis with SmaI according to PulseNet Canada procedures.Salmonella enterica serotype Braenderup strain H9812 was used as the marker size in each gel (7).For analysis, band position tolerance and optimization values of 1% were used.Similarity coefficient was obtained with the unweighted pair-group method with arithmetic averages.For strains exhibiting similar patterns with SmaI, a second enzyme (KpnI) was used to confirm their pulsed-field gel electrophoresis pattern similarity.The PulseNet Canada SmaI and KpnI pattern designations for the C. coli pulsovar 1 isolate are CASAI.0160and CAKNI.0078,respectively.Antimicrobial drug susceptibility testing was determined by using the disk diffusion method for erythromycin, tetracycline, and ciprofloxacin (8) and the Etest (AB Biodisk, Solna, Sweden) method for all 12 agents tested (3).b-lactamase susceptibility was determined as reported (9).From September 2010 through November 2011, in Montreal, 10 men, 26-57 years of age, were found to be infected with an erythromycin-susceptible, tetracycline-and ciprofloxacin-resistant C. coli pulsovar 1; these men were defined as the outbreak-associated case-patients (Figure 1).An additional 5 women and 4 men were infected with an