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Objectives We sought to analyse 10 years of longitudinal surveillance data (2007–16) from the CANWARD study and describe emerging trends in antimicrobial resistance for key bacterial pathogens across Canada. Methods Longitudinal data from CANWARD study sites that contributed isolates every year from 2007 to 2016 were analysed to identify trends in antimicrobial resistance over time using univariate tests of trend and multivariate regression models to account for the effects of patient demographics. Results Statistically significant increases occurred in the proportion of Escherichia coli isolates resistant to extended-spectrum cephalosporins, amoxicillin/clavulanate, trimethoprim/sulfamethoxazole and ciprofloxacin. Similarly, the proportion of Klebsiella pneumoniae isolates resistant to extended-spectrum cephalosporins, amoxicillin/clavulanate, trimethoprim/sulfamethoxazole, ciprofloxacin and carbapenems increased during the study. The proportion of Enterobacter cloacae isolates resistant to ceftazidime and trimethoprim/sulfamethoxazole increased. The proportion of both ESBL-positive E. coli and K. pneumoniae (including bloodstream isolates) increased significantly between 2007 and 2016. A reduction in the proportion of Pseudomonas aeruginosa that were ciprofloxacin, cefepime, colistin, amikacin and gentamicin resistant and an increase in the proportion of P. aeruginosa isolates non-susceptible to meropenem were observed. The proportion of isolates of Staphylococcus aureus non-susceptible to clarithromycin, clindamycin and trimethoprim/sulfamethoxazole decreased over time while an increase in the proportion of isolates of Streptococcus pneumoniae non-susceptible to clarithromycin, clindamycin and doxycycline was observed. Conclusions Increases in Enterobacteriaceae resistance to multiple classes of antimicrobials, increases in ESBL-positive E. coli and K. pneumoniae , and the small but significant increase in carbapenem-resistant K. pneumoniae were the most remarkable changes in antimicrobial resistance observed from 2007 to 2016 in Canada. [ABSTRACT FROM AUTHOR]

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. [ABSTRACT FROM AUTHOR]

Objectives: To describe the microbiology and antimicrobial resistance patterns of cultured samples acquired from Canadian ICUs.Methods: From 2007 to 2016, tertiary care centres from across Canada submitted 42938 bacterial/fungal isolates as part of the CANWARD surveillance study. Of these, 8130 (18.9%) were from patients on ICUs. Susceptibility testing guidelines and MIC interpretive criteria were defined by CLSI.Results: Of the 8130 pathogens collected in this study, 58.2%, 36.3%, 3.1% and 2.4% were from respiratory, blood, wound and urine specimens, respectively. The top five organisms collected from Canadian ICUs accounted for 55.4% of all isolates and included Staphylococcus aureus (21.5%), Pseudomonas aeruginosa (10.6%), Escherichia coli (10.4%), Streptococcus pneumoniae (6.5%) and Klebsiella pneumoniae (6.4%). MRSA accounted for 20.7% of S. aureus collected, with community-associated (CA) MRSA genotypes increasing in prevalence over time (P < 0.001). The highest susceptibility rates among MRSA were 100% for vancomycin, 100% for ceftobiprole, 100% for linezolid, 99.7% for ceftaroline, 99.7% for daptomycin and 99.7% for tigecycline. The highest susceptibility rates among E. coli were 100% for tigecycline, 99.9% for meropenem, 99.7% for colistin and 94.2% for piperacillin/tazobactam. MDR was identified in 26.3% of E. coli isolates, with 10.1% producing an ESBL. The highest susceptibility rates among P. aeruginosa were 97.5% for ceftolozane/tazobactam, 96.1% for amikacin, 94.7% for colistin and 93.3% for tobramycin.Conclusions: The most active agents against Gram-negative bacilli were the carbapenems, tigecycline and piperacillin/tazobactam. Against Gram-positive cocci, the most active agents were vancomycin, daptomycin and linezolid. The prevalence of CA-MRSA genotypes and ESBL-producing E. coli collected from ICUs increased significantly over time. [ABSTRACT FROM AUTHOR]

Objectives The purpose of the CANWARD study was to assess the antimicrobial activity of a variety of available agents against 22 746 pathogens isolated from patients in Canadian hospitals between 2007 and 2011. Methods Between 2007 and 2011, 27 123 pathogens were collected from tertiary-care centres from across Canada; 22 746 underwent antimicrobial susceptibility testing using CLSI broth microdilution methods. Patient demographic data were also collected. Results Of the isolates collected, 45.2%, 29.6%, 14.8% and 10.4% were from blood, respiratory, urine and wound specimens, respectively. Patient demographics were as follows: 54.4%/45.6% male/female, 12.8% ≤17 years old, 45.1% 18–64 years old and 42.1% ≥65 years old. Isolates were obtained from patients in medical and surgical wards (37.8%), emergency rooms (25.7%), clinics (18.0%) and intensive care units (18.5%). The three most common pathogens were Escherichia coli (20.1%), Staphylococcus aureus [methicillin-susceptible S. aureus and methicillin-resistant S. aureus (MRSA)] (20.0%) and Pseudomonas aeruginosa (8.0%), which together accounted for nearly half of the isolates obtained. Susceptibility rates (SRs) for E. coli were 100% meropenem, 99.9% tigecycline, 99.7% ertapenem, 97.7% piperacillin/tazobactam, 93.7% ceftriaxone, 90.5% gentamicin, 77.9% ciprofloxacin and 73.4% trimethoprim/sulfamethoxazole. Twenty-three percent of the S. aureus were MRSA. SRs for MRSA were 100% daptomycin, 100% linezolid, 100% telavancin, 99.9% vancomycin, 99.8% tigecycline, 92.2% trimethoprim/sulfamethoxazole and 48.2% clindamycin. SRs for P. aeruginosa were 90.1% amikacin, 93.1% colistin, 84.0% piperacillin/tazobactam, 83.5% ceftazidime, 82.6% meropenem, 72.0% gentamicin and 71.9% ciprofloxacin. Conclusions The CANWARD surveillance study has provided important data on the antimicrobial susceptibility of pathogens commonly causing infections in Canadian hospitals. [ABSTRACT FROM PUBLISHER]

Objectives Antimicrobial resistance patterns change over time and longitudinal surveillance studies provide insight into these trends. We sought to describe the important trends in antimicrobial resistance in key pathogens across Canada to provide useful information to clinicians, policy makers and industry, to assist in optimizing antimicrobial therapy, formulary choices and drug development. Methods We analysed longitudinal data from the CANWARD study using a multivariate regression model to control for possible effects of patient demographics on resistance, in order to assess the impact of time on antimicrobial resistance independent of other measured variables. Results We identified several key trends in common pathogens. In particular, we observed a statistically significant increase in the proportion of Escherichia coli isolates that were resistant to extended-spectrum cephalosporins and fluoroquinolones, an increase in the proportion of Klebsiella pneumoniae isolates that were resistant to extended-spectrum cephalosporins, a reduction in the proportion of Staphylococcus aureus that were methicillin, clindamycin and trimethoprim/sulfamethoxazole resistant, and a reduction in the proportion of Pseudomonas aeruginosa that were fluoroquinolone and gentamicin resistant. Conclusions Although some of these trends, such as the dramatic increase in fluoroquinolone and cephalosporin resistance in E. coli, can be attributed to the emergence and global spread of resistant clones (e.g. ST131 E. coli), others remain unexplained. However, recognizing these trends remains important to guide changes in empirical antimicrobial therapy and drug development. [ABSTRACT FROM PUBLISHER]