The objective of this study was to estimate the presence of the important foodborne pathogen Campylobacter jejuni in organically raised chickens in the province of Quebec. The recovered isolates were further characterized for their antimicrobial resistance profile, autoagglutination property and chemotaxis. Antimicrobial resistance was evaluated using agar dilution for: tetracycline, erythromycin, chloramphenicol, ciprofloxacin, gentamicin, nalidixic acid, clindamycin, ampicillin, azithromycin, bacitracin, and ceftiofur. Autoagglutination was measured by monitoring optical density changes in a bacterial suspension after 3 h of incubation at room temperature. Chemotaxis was evaluated after a contact time of 3 h between isolates and mucin, using a quantitative protocol. A total of 10 lots of chickens was sampled in August and September 2009; half of them were positive for the presence of C. jejuni. Antimicrobial resistance was found only for tetracycline (44%), erythromycin (6%), azithromycin (6%) and clindamycin (2%). Variation was observed in the minimum inhibitory concentrations (MICs) for ceftiofur and bacitracin, for which C. jejuni possess intrinsic resistance. Autoagglutination and chemotaxis varied among isolates and lot-level differences in these were observed. Autoagglutination and chemotaxis levels appeared as independent isolate properties. Further monitoring and characterization of isolates originating from organic chickens is of interest since this type of production might represent another source of exposure of consumers to a variety of the foodborne pathogen C. jejuni.

Objective—To isolate and characterize bacteriophages with strong in vitro lytic activity against various pathogenic Pseudomonas aeruginosa strains isolated from dogs with ocular infections. Sample—26 genetically distinct P aeruginosa isolates. Procedures—P aeruginosa strains were derived from dogs with naturally acquired ulcerative keratitis. From a large-scale screening for bacteriophages with potential therapeutic benefit against canine ocular infections, 2 bacteriophages (P2S2 and P5U5) were selected; host ranges were determined, and phage nucleic acid type and genetic profile were identified via enzymatic digestion. Electron microscopy was used to characterize bacteriophage ultrastructure. Bacteriophage temperature and pH stabilities were assessed by use of double-layer agar overlay titration. A cocultivation assay was used to evaluate the effect of the bacteriophages on bacterial host growth. Results—P5U5 was active against all P aeruginosa isolates, whereas P2S2 formed lytic plaques on plates of 21 (80.8%) isolates. For each bacteriophage, the genomic nucleic acid was DNA; each was genetically distinct. Ultrastructurally, P2S2 and P5U5 appeared likely to belong to the Podoviridae and Siphoviridae families, respectively. The bacteriophages were stable within a pH range of 4 to 12; however, titers of both bacteriophages decreased following heating for 10 to 50 minutes at 45° or 60°C. Growth of each P aeruginosa isolate was significantly inhibited in coculture with P2S2 or P5U5; the dose response was related to the plaque-forming unit-to-CFU ratios. Conclusions and Clinical Relevance—Bacteriophages P2S2 and P5U5 appear to be good candidates for phage treatment of infection caused by pathogenic P aeruginosa in dogs.