AUTHOR=Jia Peiyao , Zhu Ying , Li Xue , Kudinha Timothy , Yang Yang , Zhang Ge , Zhang Jingjia , Xu Yingchun , Yang Qiwen 

TITLE=High Prevalence of Extended-Spectrum Beta-Lactamases in Escherichia coli Strains Collected From Strictly Defined Community-Acquired Urinary Tract Infections in Adults in China: A Multicenter Prospective Clinical Microbiological and Molecular Study

JOURNAL=Frontiers in Microbiology

VOLUME=12

YEAR=2021

URL=https://www.frontiersin.org/journals/microbiology/articles/10.3389/fmicb.2021.663033

DOI=10.3389/fmicb.2021.663033

ISSN=1664-302X

ABSTRACT=<sec><title>Objective</title><p>The objective of the study was to investigate the antimicrobial susceptibility and extended-spectrum beta-lactamase (ESBL) positive rates of <italic>Escherichia coli</italic> from community-acquired urinary tract infections (CA-UTIs) in Chinese hospitals.</p></sec><sec><title>Materials and Methods</title><p>A total of 809 <italic>E. coli</italic> isolates from CA-UTIs in 10 hospitals (5 tertiary and 5 secondary hospitals) from different regions in China were collected during the period 2016–2017 according to the strict inclusion criteria. Antimicrobial susceptibility testing was carried out by standard broth microdilution method. Isolates were categorized as ESBL-positive, ESBL-negative, and ESBL-uncertain groups according to the CLSI recommended phenotypic screening method. ESBL and AmpC genes were amplified and sequenced on ESBL-positive and ESBL-uncertain isolates.</p></sec><sec><title>Results</title><p>The antimicrobial agents with susceptibility rates of greater than 95% included imipenem (99.9%), colistin (99.6%), ertapenem (98.9%), amikacin (98.3%), cefmetazole (97.9%), nitrofurantoin (96%), and fosfomycin (95.4%). However, susceptibilities to cephalosporins (varying from 58.6% to 74.9%) and levofloxacin (48.8%) were relatively low. In the phenotypic detection of ESBLs, ESBL-positive isolates made up 38.07% of <italic>E. coli</italic> strains isolated from CA-UTIs, while 2.97% were ESBL-uncertain. Antimicrobial susceptibilities of imipenem, cefmetazole, colistin, ertapenem, amikacin, and nitrofurantoin against ESBL-producing <italic>E. coli</italic> strains were greater than 90%. The percentage of ESBL-producing strains was higher in male (53.6%) than in female patients (35.2%) (<italic>p</italic> &lt; <italic>0.001</italic>). CTX-M-14 (31.8%) was the major CTX-M variant in the ESBL-producing <italic>E. coli</italic>, followed by CTX-M-55 (23.4%), CTX-M-15 (17.5%), and CTX-M-27 (13.3%). The prevalence of carbapenem-resistant <italic>E. coli</italic> among CA-UTI isolates was 0.25% (2/809).</p></sec><sec><title>Conclusion</title><p>Our study indicated high prevalence of ESBL in <italic>E. coli</italic> strains from strictly defined community-acquired urinary tract infections in adults in China. Imipenem, colistin, ertapenem, amikacin, and nitrofurantoin were the most active antimicrobials against ESBL-positive <italic>E. coli</italic> isolates. <italic>bla</italic><sub><italic>CTX–M–</italic></sub><sub>14</sub> is the predominant <italic>esbl</italic> gene in ESBL-producing and ESBL-uncertain strains. Our study indicated that the use of cephalosporins and fluoroquinolone needs to be restricted for empirical treatment of CA-UTIs in China.</p></sec>