Exposure to microorganisms resistant to antimicrobials may constitute a health risk to human populations. It is believed that one route of exposure occurs when people engage in recreational activities in water contaminated with these microorganisms. The main objective of this study was to explore population-level and environmental determinants specifically associated with the presence of antimicrobial resistant (AMR) generic Escherichia coli isolated from recreational waters sampled from beaches located in southern Quebec, Canada. Water samples originated from the Quebec provincial beach surveillance program for the summers of 2004 and 2005. This study focused on three classes of determinants, namely: agricultural, population-level and beach characteristics for a total of 19 specific factors. The study was designed as a retrospective observational analysis and factors were assessed using logistic regression methods. From the multivariable analysis, the data suggested that the percentage of land used for spreading liquid manure was a significant factor associated with the presence of AMR E. coli (OR=27.73). Conceptually, broad factors potentially influencing the presence of AMR bacteria in water must be assessed specifically in addition to factors associated with general microbial contamination. Presence of AMR E. coli in recreational waters from beaches in southern Quebec may represent a risk for people engaging in water activities and this study provides preliminary evidence that agricultural practices, specifically spreading liquid manure in agricultural lands nearby beaches, may be linked to the contamination of these waters by AMR E. coli.
In 2006, the Canadian Integrated Program for Antimicrobial Resistance Surveillance (CIPARS) Farm Program was implemented in sentinel grower-finisher swine herds in Québec, Ontario, Manitoba, Saskatchewan and Alberta. Herds were visited 1-3 times annually. Faecal samples were collected from pens of close-to-market (CTM) weight (>80 kg) pigs and antimicrobial use (AMU) data were collected via questionnaires. Samples were cultured for generic Escherichia coli and Salmonella and tested for antimicrobial susceptibility. This paper describes the findings of this program between 2006 and 2008. Eighty-nine, 115 and 96 herds participated in this program in 2006, 2007 and 2008 respectively. Over the 3 years, antimicrobial resistance (AMR) levels remained consistent. During this period, resistance to one or more antimicrobials was detected in 56-63% of the Salmonella spp. isolates and 84-86% of E. coli isolates. Resistance to five or more antimicrobials was detected in 13-23% of Salmonella and 12-13% of E. coli. Resistance to drugs classified as very important to human health (Category I) by the Veterinary Drug Directorate (VDD), Health Canada, was less than or equal to 1% in both organisms. AMU data were provided by 100 herds in 2007 and 95 herds in 2008. Nine herds in 2007 and five herds in 2008 reported no AMU. The most common route of antimicrobial administration (75-79% of herds) was via feed, predominantly macrolides/lincosamides (66-68% of herds). In both 2007 and 2008, the primary reasons given for macrolide/lincosamide use were disease prevention, growth promotion and treatment of enteric disease. The Category I antimicrobials, ceftiofur and virginiamycin were not used in feed or water in any herds in 2008, but virginiamycin was used in feed in two herds in 2007. Parenteral ceftiofur was used in 29 herds (29%) in 2007 and 20 herds (21%) in 2008. The reasons for ceftiofur use included treatment of lameness, respiratory disease and enteric disease.
Streptococcus agalactiae is considered one of the major causes of bovine intramammary infections. It is also found in the vaginas of women without any apparent clinical symptoms, but reports of neonatal infections, causing significant morbidity, are relatively frequent. The aim of this study was to evaluate the genetic diversity of S. agalactiae strains isolated from bovine milk and from asymptomatic women in Qu?bec, Canada, by randomly amplified polymorphic DNA (RAPD) analysis. A total of 185 bovine isolates and 38 human isolates were first serotyped for capsular polysaccharide by double diffusion in agarose gel (bovine isolates) and coagglutination (human isolates). Strains were then studied by RAPD using 3 primers, designated OPS11, OPB17, and OPB18, which were selected from 12 primers. Thirty-eight percent of bovine isolates and 82% of human isolates could be serotyped. Prevalent serotypes were type III (28%) for bovine isolates and types V (26%) and III (24%) for human isolates. RAPD results showed that, taken together, all isolates (of bovine and human origin) shared 58% similarity. Ninety-four percent of these isolates were clustered in four groups (I, II, III, and IV) with 70% similarity among them. Three clusters, A (48 isolates), B (14 isolates), and C (32 isolates), with 79 to 80% similarity were identified within group IV, whereas the three other groups did not present any clusters. Despite some clustering of human isolates, relatively high diversity was seen among them. Relatively high heterogeneity was observed with the RAPD profiles, not only for field strains belonging to different serotypes but also for those within a given serotype.