Drug susceptibility and molecular epidemiology of Escherichia coli in bloodstream infections in Shanxi, China

Abstract

Objectives We carried out a retrospective study to investigate the drug susceptibility and genetic relationship of clinical Escherichia coli isolates from patients with BSIs in Shanxi, China. Methods E. coli isolates causing BSIs were consecutively collected from June 2019 to March 2020. Antimicrobial susceptibility testing was performed by broth microdilution method. PCR was used to detect antimicrobial resistance genes coding for extended-spectrum β-lactamases (ESBLs), phylogenetic groups and seven housekeeping genes of E. coli. Results A total of 76 E. coli were collected. Antimicrobial susceptibility testing revealed that the top six E. coli resistant antibiotics were ampicillin (90.7%), ciprofloxacin (69.7%), cefazolin (65.7%), levofloxacin (63.1%), ceftriaxone and cefotaxime (56.5%). Among the 76 isolates, 43 produced ESBLs. Molecular analysis showed that CTX-M-14 was the most common ESBLs, followed by CTX-M-15 and CTX-M-55. Phylogenetic group D (42.2%) predominated, followed by group B2 (34.2%), group A (18.4%) and group B1 (5.2%). The most prevalent sequence types (STs) were ST131 (15/76), ST69 (12/76) and ST38 (6/76). Conclusions This study is the first to report the phenotypic and molecular characteristics of E. coli isolated from BSIs in Shanxi, China. Our results indicated a high prevalence of MDR in E. coli strains isolated from BSIs and a serious spread of ESBL genes in Shanxi, especially the epidemiological blaCTX-M. Phylogenetic analysis indicated genetic diversity among E. coli BSIs isolates.

Implications of different waterfowl farming on cephalosporin resistance: Investigating the role of blaCTX-M-55

“…Among the phylogenetic groupings, the 3 groups with the highest detection rates were phylogroup A (21), phylogroup C (12), followed by phylogroup B1 (9) ( Table 4 ). Previous reports have indicated that strains carrying bla CTX-M-55 are commonly associated with phylogroup B1, but the high detection rate of phylogroup C is a novel finding ( Rao et al, 2014 ; Zurfluh et al, 2015 ; Ortega-Paredes et al, 2019 ; Song et al, 2020 ; Zhang et al, 2021b ; Yoon and Lee, 2022 ). It is important to note that 2 strains belonged to phylogroup B2, which was recognized as an opportunistic extraintestinal pathogen and often carried genes associated with virulence ( Clermont et al, 2000 ).…”

Molecular exploring of multidrug resistance update of E.coli causing neonatal calves’ diarrhea.

“…This can be attributed to increasing microbial drug resistance development or differences in antibiotic stress on E. coli due to differences in the management and preventive control measures in other studied localities. Recent studies have reported strains of E. coli with advanced resistance to most antibiotic classes (Xiao et al 2019, Zhang et al 2021. As E. coli is considered the most active and smart bacteria for developing drug-resistance genes, the more advanced the antibacterial stress it faces, the more resistant genes emerge.…”