Mahoney MT, Brigman HV, Johnston BD, Johnson JR, Hirsch EB. Prevalence and characteristics of multidrug-resistant Escherichia coli sequence type ST131 at two academic centers in Boston and Minneapolis, USA.
Am J Infect Control 2022;
51:434-439. [PMID:
35764181 DOI:
10.1016/j.ajic.2022.06.019]
[Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/12/2022] [Revised: 06/16/2022] [Accepted: 06/20/2022] [Indexed: 11/01/2022]
Abstract
BACKGROUND
Escherichia coli sequence type (ST) ST131, with its emergent resistance-associated H30Rx, H30R1, and C1-M27 clonal subsets, accounts for the greatest share of extraintestinal E. coli infections and most extended-spectrum β-lactamase (ESBL)-producing E. coli.
METHODS
We characterized and compared consecutive E. coli urine isolates from two geographically distinct medical centers in Minneapolis, Minnesota (n = 172) and Boston, Massachusetts (n = 143) for ESBL phenotype, CTX-M-type ESBL genes, phylogenetic groups, selected ST131 subclones, and 40 extraintestinal virulence genes.
RESULTS
Whereas the Boston vs. Minneapolis isolates had a similar prevalence of phylogenetic groups (mainly B2: 79% vs 73%), ST131 (34% vs 28%), H30 (28% vs 21%), and H30Rx (6% vs 5%), the emerging C1-M27 subclone occurred uniquely among Boston (6%) isolates. ESBL production was more prevalent among Boston isolates (15% vs 8%) and among ST131 isolates. Identified ESBL genes included blaCTX-M-27 (Boston only) and blaCTX-M-15. Ciprofloxacin resistance was ST131-associated and similarly prevalent across centers. Boston isolates had higher virulence gene scores.
CONCLUSIONS
Despite numerous similarities to Minneapolis isolates, Boston ST131 isolates demonstrated more prevalent ESBL production, higher virulence gene scores, and, uniquely, the C1-M27 subclone and blaCTX-M-27. Broader surveillance is needed to define the prevalence of ST131's globally successful C1-M27 subclone across the U.S.
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