Scientific Publications Database
Article Title: Dramatic rise in the proportion of ESBL-producing Escherichia coli and Klebsiella pneumoniae among clinical isolates identified in Canadian hospital laboratories from 2007 to 2016Authors: Denisuik, Andrew J.; Karlowsky, James A.; Adam, Heather J.; Baxter, Melanie R.; Lagace-Wiens, Philippe R. S.; Mulvey, Michael R.; Hoban, Daryl J.; Zhanel, George G.; Nichol, Kimberly A.; Walkty, Andrew; Blondeau, J.; Slinger, R.; Davidson, R.; Zhanel, G.; Hoban, D.; Delport, J.; Ellis, C.; Laverdiere, M.; Loo, V; Poutanen, S.; Fuller, J.; Roscoe, D.; Desjardins, M.; Matukas, L.; Goyette, M.; Lee, C.; Carignan, A.; Bergevin, M.; Pelletier, R.
Journal: JOURNAL OF ANTIMICROBIAL CHEMOTHERAPY Volume 74
Date of Publication:2019
Abstract:
Objectives: To assess the prevalence, antimicrobial susceptibilities and molecular characteristics of ESBL-producing Escherichia coli and Klebsiella pneumoniae infecting patients receiving care in Canadian hospitals from January 2007 to December 2016.Methods: Clinical isolates of E. coli (n=8387) and K. pneumoniae (n=2623) submitted to CANWARD, an ongoing Canadian national surveillance study, were tested using the CLSI reference broth microdilution method to determine their susceptibility to 15 antimicrobial agents. ESBL-producing E. coli and K. pneumoniae confirmed by the CLSI phenotypic method and putative AmpC-producing E. coli underwent PCR testing and DNA sequencing to identify resistance genes. Annual proportions of isolates harbouring ESBL and AmpC genes were assessed by the Cochran-Armitage test of trend.Results: The annual proportion of isolates of E. coli that were ESBL producing increased from 3.4% in 2007 to 11.1% in 2016 (P<0.0001); >95% of ESBL-producing E. coli were susceptible to amikacin, colistin, ertapenem, meropenem and tigecycline. The proportion of isolates of K. pneumoniae that were ESBL producing increased from 1.3% in 2007 to 9.7% in 2016 (P<0.0001); >95% of ESBL-producing K. pneumoniae were susceptible to amikacin and meropenem. CTX-M-15 was the predominant genotype in both ESBL-producing E. coli (64.2% of isolates) and ESBL-producing K. pneumoniae (51.0%). The annual proportion of isolates of E. coli that were AmpC producing [annual proportion mean 1.9% (range 0.3%-3.1%)] was unchanged from 2007 to 2016 (P>0.5).Conclusions: The prevalence of both ESBL-producing E. coli and K. pneumoniae increased significantly in Canada during the study period while the prevalence of AmpC-producing E. coli remained low and stable.