Zhanel GG, Decorby M, Laing N, Weshnoweski B, Vashisht R, Tailor F, Nichol KA, Wierzbowski A, Baudry PJ, Karlowsky JA, Lagacé-Wiens P, Walkty A, McCracken M, Mulvey MR, Johnson J, Hoban DJ Antimicrobial Resistant Pathogens in Intensive Care Units in Canada: Results of the Canadian National Intensive Care Unit (CAN-ICU) Study, 2005/2006. [JOURNAL ARTICLE] Antimicrob Agents Chemother 2008 Feb 19.
Between September 1, 2005 and June 30, 2006, 19 medical centres collected 4,180 isolates recovered from clinical specimens in Canadian intensive care units (ICUs). The 4,180 isolates were collected from respiratory, 2,292 (54.8%); blood, 738 (17.7%); wounds/tissue, 581 (13.9%); and urinary 569 (13.6%) specimens. The ten most common organisms isolated from 79.5% of all clinical specimens were methicillin-susceptible Staphylococcus aureus (MSSA, 16.4%), Escherichia coli (12.8%), Pseudomonas aeruginosa (10.0%), Haemophilus influenzae (7.9%), coagulase-negative staphylococci/Staphylococcus epidermidis (6.5%), Enterococcus spp. (6.1%), Streptococcus pneumoniae (5.8%), Klebsiella pneumoniae (5.8%), methicillin-resistant Staphylococcus aureus (MRSA, 4.7%), and Enterobacter cloacae (3.9%). MRSA made up 22.3% (197/884) of all S. aureus (90.9% of MRSA were healthcare-associated-HA-MRSA and 9.1% were community-associated-CA-MRSA) while vancomycin-resistant enterococci (VRE) made up 6.7% (11/255) of all enterococci (88.2% of VRE had the vanA genotype). Extended-spectrum ss-lactamase (ESBL) producing E. coli and K. pneumoniae occurred in 3.5% (19/536) and 1.8% (4/224) of isolates, respectively. All 19 ESBL-producing E. coli were PCR-positive for CTX-M, with blaCTX-M-15 occurring in 74% (14/19) of isolates. With MRSA, no resistance was observed to daptomycin, linezolid, tigecycline, and vancomycin, while resistance rates to other agents were: clarithromycin 89.9%, clindamycin 76.1%, fluoroquinolones 90.1-91.8%, and trimethoprim-sulfamethoxazole 11.7%. With E. coli, no resistance was observed to amikacin, meropenem and tigecycline, while resistance rates to other agents were: cefazolin 20.1%, cefepime 0.7%, ceftriaxone 3.7%, gentamicin 3.0%, fluoroquinolones 21.1%, piperacillin/tazobactam 1.9%, and trimethoprim-sulfamethoxazole 24.8%. Resistance rates with P. aeruginosa were: amikacin 2.6%, cefepime 10.2%, gentamicin 15.2%, fluoroquinolones 23.8-25.5%, meropenem 13.6%, and piperacillin/tazobactam 9.3%. A multi-drug resistant (MDR) phenotype (resistance to >/= 3 of cefepime, piperacillin/tazobactam, meropenem, amikacin or gentamicin, and ciprofloxacin) occurred frequently in P. aeruginosa (12.6%) but uncommonly in E. coli (0.2%), E. cloacae (0.6%) or K. pneumoniae (0%). In conclusion, S. aureus (MSSA and MRSA), E. coli, P. aeruginosa, H. influenzae, Enterococcus spp., S. pneumoniae, and K. pneumoniae are the most common isolates recovered from clinical specimens in Canadian ICUs. A MDR phenotype is common with P. aeruginosa in Canadian ICUs.
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