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

Peiyao Jia; Ying Zhu; Xue Li; Timothy Kudinha; Yang Yang; Ge Zhang; Jingjia Zhang; Yingchun Xu; Qiwen Yang

doi:10.3389/fmicb.2021.663033

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

Front Microbiol. 2021 Jul 7:12:663033. doi: 10.3389/fmicb.2021.663033. eCollection 2021.

Authors

Peiyao Jia^{1

2}, Ying Zhu^{1

2}, Xue Li^{1

3}, Timothy Kudinha^{4

5}, Yang Yang¹, Ge Zhang¹, Jingjia Zhang¹, Yingchun Xu¹, Qiwen Yang¹

Affiliations

¹ Department of Clinical Laboratory, State Key Laboratory of Complex Severe and Rare Diseases, Peking Union Medical College Hospital, Chinese Academy of Medical Sciences and Peking Union Medical College, Beijing, China.
² Graduate School, Peking Union Medical College, Chinese Academy of Medical Sciences, Beijing, China.
³ Department of Clinical Laboratory, Beijing Anzhen Hospital, Capital Medical University, Beijing, China.
⁴ School of Biomedical Sciences, Charles Sturt University, Orange, NSW, Australia.
⁵ NSW Health Pathology, Regional and Rural, Orange Hospital, Orange, NSW, Australia.

Abstract

Objective: The objective of the study was to investigate the antimicrobial susceptibility and extended-spectrum beta-lactamase (ESBL) positive rates of Escherichia coli from community-acquired urinary tract infections (CA-UTIs) in Chinese hospitals.

Materials and methods: A total of 809 E. coli 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.

Results: 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 E. coli strains isolated from CA-UTIs, while 2.97% were ESBL-uncertain. Antimicrobial susceptibilities of imipenem, cefmetazole, colistin, ertapenem, amikacin, and nitrofurantoin against ESBL-producing E. coli strains were greater than 90%. The percentage of ESBL-producing strains was higher in male (53.6%) than in female patients (35.2%) (p < 0.001). CTX-M-14 (31.8%) was the major CTX-M variant in the ESBL-producing E. coli, followed by CTX-M-55 (23.4%), CTX-M-15 (17.5%), and CTX-M-27 (13.3%). The prevalence of carbapenem-resistant E. coli among CA-UTI isolates was 0.25% (2/809).

Conclusion: Our study indicated high prevalence of ESBL in E. coli 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 E. coli isolates. bla _CTX-M- ₁₄ is the predominant esbl 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.

Keywords: CTX-M; Escherichia coli; antibiotic resistance; community-acquired urinary tract infections; empirical treatment; extended-spectrum beta-lactamase.