Dominance of CTX-M-Type Extended-Spectrum β-Lactamase (ESBL)-Producing Escherichia coli Isolated from Patients with Community-Onset and Hospital-Onset Infection in China

Abstract

ObjectiveTo investigate CTX-M genotypes among extended-spectrum β-lactamase-producing Escherichia coli (ESBL-EC) isolated from patients with community-onset and hospital-onset infections in China, their clonality and the distribution of CTX-M variants in different specimens of community-onset and hospital-onset infections.MethodsESBL-EC isolates were collected from general hospitals from 2011 to 2012 in China. Broth microdilution method antimicrobial susceptibility testing of 16 antibiotics was performed. Clinical data from community-onset and hospital-onset infections due to ESBL-EC were analyzed. ESBL-encoding genes were amplified by PCR and sequenced, and multilocus sequence typing (MLST) was performed for a random selection of predominant CTX-M type strains identified.ResultsA total of 1,168 ESBL-EC isolates were obtained from various clinical specimens, 41.7% of which were responsible for causing community-onset infections. The presence of urinary calculi was higher in community-onset infections, whereas malignancy, cardiovascular and cerebrovascular diseases, dementia, chronic renal disease, diabetes mellitus and surgical treatment were found to have higher proportions in hospital-onset infections. There was no significant difference in trauma between community-onset and hospital-onset infections. 96.2% of the isolates were detected to harbor bla CTX-M genes. bla CTX-M-1 group and bla CTX-M-9 group were detected at 40.7% and 48.7% respectively, and both positive group accounted for 10.6%. bla CTX-M-55 (24.8%) and bla CTX-M-15 (18.2%) were the major genotypes in bla CTX-M-1 group while bla CTX-M-14 (46.8%) was predominant in bla CTX-M-9 group. A comparison of bla CTX-M distribution in different specimens between ESBL-EC causing community-onset and hospital-onset infection showed no significant difference. A total of 229 isolates were tested for MLST. ST131 (14%) was the predominant type. ST648, ST405 and ST1193 were also detected.ConclusionsCommunity-onset ESBL-EC has emerged as a common pathogen in China. CTX-M-14 is the most commonly encountered, CTX-M-55 and CTX-M-15 have spread rapidly. ST131 is the predominant clonal group, and the great diversity of CTX-M-producing isolates of E. coli has emerged in China.

Molecular Epidemiology and Genetic Diversity of Fluoroquinolone-Resistant Escherichia coli Isolates from Patients with Community-Onset Infections in 30 Chinese County Hospitals

“…A recent Chinese hospital study of the main MLSTs associated with extended-spectrum ␤-lactamase (ESBL)-producing strains of E. coli harboring CTX-M-14, CTX-M-55, or CTX-M-15 genes reported that the most common STs were ST131 (14.6%), ST1193 (7.9%), ST405 (6.6%), ST69 (6.3%), and ST648 (6.3%) (21). Prior to this study, ST1193 was unreported in China and was not identified among ESBL (CTX-M-14 or CTX-M-15)-producing E. coli isolates from infections in Korea and uropathogenic E. coli strains in northwest England (22,23).…”

Development of a multiplex PCR system and its application in detection of blaSHV, blaTEM, blaCTX-M-1, blaCTX-M-9 and blaOXA-1 group genes in clinical Klebsiella pneumoniae and Escherichia coli strains

“…Thus, it could be a useful tool in China and other countries where bla CTX-M-1 and bla CTX-M-9 gene clusters, among others, have been reported to be on the rise. 9,[31][32][33] For instance, these enzymes, with varying prevalence rates, have also been reported in many countries in the Asia-Pacific region. 34 Although CTX-M group enzymes emerged later compared with TEM and SHV types, they have spread worldwide and specific subgroups have been localized in different geographic regions.…”

Antibiotic Susceptibility Profile, ESBL Production and blaCTX-M1, blaSHV and blaTEM Types Among Escherichia coli Blood Isolates

“…Similarly, results from previous molecular studies have demonstrated that bla CTX-M1 is endemic and is present among ST131 or non ST131 clones in healthcare and community settings. [16][17][18][19] The bla CTXM1 was detected in the range of 4-32 ug/mL ceftazidime, although higher MIC was associated with MDR and presence of both bla CTXM1 and bla SHV genes. It has been demonstrated that bla CTXM1/14 and bla CTXM-15 genes cause high level of resistance to cefepime/ceftriaxone and ceftazidime, respectively.…”