J Y M Johnson

Publications (2)4.21 Total impact

• Article: Risk factors for ciprofloxacin resistance in reported Campylobacter infections in southern Alberta.

  J Y M Johnson, L M McMullen, P Hasselback, M Louie, G Jhangri, L D Saunders
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  ABSTRACT: We conducted a case-control study examining risk factors for ciprofloxacin resistance in Campylobacter infections that were reported in 2004 and 2005 in two health regions in southern Alberta. The study questionnaire included questions about recent travel and antibiotic use, food consumption frequency, use of household and personal hygiene products with antibacterial agents, contact with animals, and potential misuse of antibiotics. Of the 210 patients who participated, 31.0% had ciprofloxacin-resistant Campylobacter infections. Foreign travel was the strongest predictor of resistance. Surprisingly, possession of antibiotics for future use was identified as a risk factor for resistance. We also examined the potential for participation bias and resistance misclassification to affect the resulting multivariable models. Participation bias appears to have had a substantial effect on the model results, but the estimated misclassification effect due to the use of different ciprofloxacin susceptibility testing methods was only slight.
  Epidemiology and Infection 08/2008; 136(7):903-12. · 2.84 Impact Factor
• Article: Prevalence of Escherichia coli O157:H7 and Salmonella spp. in surface waters of southern Alberta and its relation to manure sources.

  J Y M Johnson, J E Thomas, T A Graham, I Townshend, J Byrne, L B Selinger, V P J Gannon
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  ABSTRACT: The Oldman River watershed in southern Alberta, Canada, is an extensively irrigated region in which intensive agricultural practices have flourished. Concern over water quality in the basin has been expressed because of high levels of enteric disease indigenous to the region. To address these concerns, we conducted a 2-year study to estimate the prevalence of Escherichia coli O157:H7 and Salmonella spp. in surface water within the basin. This study is the first of its kind to identify E. coli O157:H7 repeatedly in surface water collected from a Canadian watershed. Prevalence of E. coli O157:H7 and Salmonella spp. in water samples was 0.9% (n = 1,483) and 6.2% (n = 1,429), respectively. While data examined at a regional level show a relationship between high livestock density and high pathogen levels in southern Alberta, statistical analysis of point source data indicates that predicted manure output from bovine, swine, and poultry feeding operations was not directly associated with either Salmonella spp. or E. coli O157:H7 prevalence. However, geography and weather variables, which are likely to influence bacterial runoff, were not considered in this model. We also postulate that variations in time, amount, and frequency of manure application onto agricultural lands may have influenced levels of surface-water contamination with these bacterial pathogens.
  Canadian Journal of Microbiology 06/2003; 49(5):326-35. · 1.36 Impact Factor