42936 pathogens from Canadian hospitals: 10 years of results (2007-16) from the CANWARD surveillance study

Objectives: The CANWARD surveillance study was established in 2007 to annually assess the in vitro susceptibilities of a variety of antimicrobial agents against bacterial pathogens isolated from patients receiving care in Canadian hospitals. Methods: 42 936 pathogens were received and CLSI broth microdilution testing was performed on 37 355 bacterial isolates. Limited patient demographic data submitted with each isolate were collated and analysed. Results: Of the isolates tested, 43.5%, 33.1%, 13.2% and 10.2% were from blood, respiratory, urine and wound specimens, respectively; 29.9%, 24.8%, 19.0%, 18.1%and 8.2% of isolates were from patients in medical wards, emergency rooms, ICUs, hospital clinics and surgical wards. Patient demographics associated with the isolates were: 54.6%male/45.4% female; 13.1%patients aged ≤17 years, 44.3% 18-64 years and 42.7% ≥65 years. The three most common pathogens were Staphylococcus aureus (21.2%, both methicillin-susceptible and MRSA), Escherichia coli (19.6%) and Pseudomonas aeruginosa (9.0%). E. coli were most susceptible to meropenem and tigecycline (99.9%), ertapenem and colistin (99.8%), amikacin (99.7%) and ceftolozane/tazobactam and plazomicin (99.6%). Twenty-three percent of S. aureus were MRSA. MRSA were most susceptible to ceftobiprole, linezolid and telavancin (100%), daptomycin (99.9%), vancomycin (99.8%) and tigecycline (99.2%). P. aeruginosa were most susceptible to ceftolozane/tazobactam (98.3%) and colistin (95.0%). Conclusions: The CANWARD surveillance study has provided 10 years of reference antimicrobial susceptibility testing data on pathogens commonly causing infections in patients attending Canadian hospitals.