Dataset Information

Nationwide high prevalence of CTX-M and an increase of CTX-M-55 in Escherichia coli isolated from patients with community-onset infections in Chinese county hospitals.

ABSTRACT:

Background

In order to investigate the epidemiology, molecular characteristics, and distribution of extended-spectrum ?-lactamase (ESBL)- and AmpC-producing Escherichia coli from community-onset infections in Chinese county hospitals.

Methods

E. coli isolates were collected from patients with community-onset infections in 30 county hospitals. ESBL activity was confirmed by double-disc diffusion. Genetic confirmation and molecular typing of ESBL- and AmpC-producing isolates was determined by PCR and DNA sequencing. ESBL-positive isolates were further characterised by multi-locus sequence typing.

Results

Of 550 E. coli isolates, 256 (46.5%) carried ESBL genes and all were of the CTX-M type. The prevalence of ESBL-producing strains varied from 30.2% to 57.0% across different regions of China. Overall, 12 bla CTX-M subtypes were detected; the most abundant were bla CTX-M-14 (163/256 isolates, 64.5%), bla CTX-M-55 (47/256, 18.4%), and bla CTX-M-15 (31/256, 12.1%). CMY-2-like AmpC ?-lactamases were detected in 11 strains, three of which co-existed with bla CTX-M. A total of 64 sequence types (STs) were detected in 256 ESBL-producing strains, including nine that were new. ST131 was the most abundant type (27 isolates, 12.7%), followed by ST69 (14 isolates, 6.6%), ST405 (14 isolates, 6.6%), and ST38 (12 isolates, 5.6%).

Conclusions

This study revealed that the widespread prevalence of ESBLs among outpatient infections has reached a high level in county hospitals. The CTX-M genotype was most dominant, comprising a variety of subtypes. This is the first time the incidence of CTX-M-55 has exceeded that of CTX-M-15 in China. No predominant ST was detected, suggesting that ESBL-producing E. coli strains originate in different clones.

SUBMITTER: Zhang J

PROVIDER: S-EPMC4265337 | biostudies-literature | 2014 Dec

REPOSITORIES: biostudies-literature

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Publications

Nationwide high prevalence of CTX-M and an increase of CTX-M-55 in Escherichia coli isolated from patients with community-onset infections in Chinese county hospitals.

Zhang Jing J Zheng Beiwen B Zhao Lina L Wei Zeqing Z Ji Jinru J Li Lanjuan L Xiao Yonghong Y

BMC infectious diseases 20141203

<h4>Background</h4>In order to investigate the epidemiology, molecular characteristics, and distribution of extended-spectrum β-lactamase (ESBL)- and AmpC-producing Escherichia coli from community-onset infections in Chinese county hospitals.<h4>Methods</h4>E. coli isolates were collected from patients with community-onset infections in 30 county hospitals. ESBL activity was confirmed by double-disc diffusion. Genetic confirmation and molecular typing of ESBL- and AmpC-producing isolates was det ...[more]

PMID: 25466590

Similar Datasets

Project description: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 blaCTX-M genes. blaCTX-M-1 group and blaCTX-M-9 group were detected at 40.7% and 48.7% respectively, and both positive group accounted for 10.6%. blaCTX-M-55 (24.8%) and blaCTX-M-15 (18.2%) were the major genotypes in blaCTX-M-1 group while blaCTX-M-14 (46.8%) was predominant in blaCTX-M-9 group. A comparison of blaCTX-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.

Project description:In recent years, blaCTX-M-55-positive Escherichia coli has been widely reported in multiple locations with an increasing trend in prevalence, yet few studies have comprehensively analyzed the transmission characteristics and epidemiological patterns of blaCTX-M-55-positive E. coli. Here, we constructed a blaCTX-M-55-positive E. coli global genomic data set as completely as possible and explored the epidemiology and potential impact of blaCTX-M-55-positive E. coli on a global scale by high-resolution bioinformatics methods. The results show that blaCTX-M-55-positive E. coli has spread widely worldwide, especially in Asia, with the rich sequence typing (ST) diversity and high proportion of auxiliary genome occupancy indicating a high degree of openness. The phylogenetic tree suggests that blaCTX-M-55-positive E. coli is frequently clonally transmitted between the three human-animal environments and often cotransmitted with fosA, mcr, blaNDM, and tet(X). The stable presence of InclI1 and InclI2 in different hosts from different sources suggests that this part of the plasmid drives the widespread transmission of blaCTX-M-55-positive E. coli. We inductively clustered all blaCTX-M-55 flanking environmental gene structures and obtained five types. Notably, "ISEcp1-blaCTX-M-55-orf477-(Tn2)" and "IS26(IS15DI)-hp-hp-blaCTX-M-55-orf477-hp-blaTEM-IS26-hp-IS26-Tn2" are dominant in "humans" and in "animals and related foods," respectively. Overall, our findings highlight the importance of whole-genome sequencing-based surveillance in exploring the transmission and evolution of blaCTX-M-55-positive E. coli in the context of "One Health," and they serve as a reminder to strengthen the surveillance of blaCTX-M-55-positive E. coli in order to address the potential risk of future large outbreaks. IMPORTANCE CTX-M-55 was first discovered in Thailand in 2004, and today, this enzyme is the most common CTX-M subtype in E. coli of animal origin in China. Thus, blaCTX-M-55-positive E. coli getting widely spread is a growing public health problem. Although prevalence surveys of blaCTX-M-55-positive E. coli in different hosts have been widely reported in recent years, they remain insufficient in "One Health" context and from a global comprehensive perspective. Here, we constructed a genomic database of 2144 blaCTX-M-55-positive E. coli and used bioinformatics methods to resolve the spread and evolution of blaCTX-M-55-positive E. coli. The results suggest a potential risk of rapid transmission of blaCTX-M-55-positive E. coli and that long-term continuous surveillance of blaCTX-M-55-positive E. coli should be emphasized.

Project description:In recent years, the CTX-M-55 extended-spectrum β-lactamase (ESBL)-positive rate has gradually increased in the clinic. To identify the molecular epidemiology and characteristics of bla CTX-M -55-positive isolates, a total of 374 non-repetitive ESBL-producing Escherichia coli strains were collected from patients in two hospitals in Guangzhou, and 89 bla CTX-M -55-positive isolates were selected by CTX-M-1-group PCR amplification and confirmed by DNA sequencing. Whole-genome sequencing was used to analyze the resistance phenotype, plasmid types, phylogenetic relationships and genetic environment of the bla CTX-M -55 gene. Conjugation experiments and PCR were performed to confirm whether the plasmid harboring bla CTX-M-55 gene could be transferred. The results showed that all bla CTX-M-55-positive isolates were resistant to ceftriaxone, and 88.76 and 76.40% were resistant to ceftazidime and cefepime, respectively. The resistance rates to levofloxacin and sulfamethoxazole were 66.29 and 59.55%, respectively. However, the sensitivity rate of piperacillin/tazobactam, amoxicillin/clavulanate, and amikacin exceeded 90%. All bla CTX-M-55-positive isolates were sensitive to carbapenems. Thirty-two STs were detected in the bla CTX-M-55-positive isolates, among which the detection rate of ST1193 was relatively high (19.10%, 17/89), and other ST types were scattered. It remains to be seen whether ST1193 carrying the bla CTX-M -55 gene can become a popular clone strain in this region in the future. The plasmid types carrying the bla CTX-M -55 gene included IncI1, IncFII, IncFIC, IncFIB, IncHI2, IncI2, and IncX/Y, among which the IncI1 and IncFII plasmids were the main plasmids, accounting for 37.80 and 28.09%, respectively. Among them, 11 strains of the IncI1 plasmid existed in ST1193 strains. The bla CTX-M -55 gene was found on chromosomes of 13 isolates, and seemed to be increasing annually. Up to five distinct types of genetic environments surrounding the bla CTX-M -55 gene were analyzed. The most common structure was type II "ISEcp1-bla CTX-M -55-ORF477." In conclusion, whether ST1193, which carries bla CTX-M -55 gene, will be an epidemic clone of this region in the future remains to be concerned. The plasmids IncI1 and IncFII, and mobile elements such as ISEcp1 and IS26 may be the main factors leading to the spread and prevalence of CTX-M-55 genotypes.

Project description:BACKGROUND:The spreading of antibiotic resistant bacteria is becoming nowadays an alarming threat to human and animal health. There is increasing evidence showing that wild birds could significantly contribute to the transmission and spreading of drug-resistant bacteria. However, data for antimicrobial resistance in wild birds remain scarce, especially throughout Africa. The aims of this investigation were to analyze the prevalence of ESBL-producing E. coli in faecal samples of wild birds in Tunisia and to characterize the recovered isolates. RESULTS:One hundred and eleven samples were inoculated on MacConkey agar plates supplemented with cefotaxime (2 ?g/ml). ESBL-producing E. coli isolates were detected in 12 of 111 faecal samples (10.81%) and one isolate per sample was further characterized. ?-lactamase detected genes were as follows: blaCTX-M-15 (8 isolates), blaCTX-M-15?+?blaTEM-1b (4 isolates). The ISEcp1 and orf477 sequences were found respectively in the regions upstream and downstream of all blaCTX-M-15 genes. Seven different plasmid profiles were observed among the isolates. IncF (FII, FIA, FIB) and IncW replicons were identified in 11 CTX-M-15 producing isolates, and mostly, other replicons were also identified: IncHI2, IncA/C, IncP, IncI1 and IncX. All ESBL-producing E. coli isolates were integron positive and possessed "empty" integron structures with no inserted region of DNA. The following detected virulence genes were: (number of isolates in parentheses): fimA (ten); papC (seven); aer (five); eae (one); and papGIII, hly, cnf, and bfp (none). Molecular typing using pulsed-field gel electrophoresis and multilocus sequence typing showed a low genetic heterogeneity among the 12 ESBL-producing strains with five unrelated PFGE types and five different sequence types (STs) respectively. CTX-M-15-producing isolates were ascribed to phylogroup A (eleven isolates) and B2 (one isolate). CONCLUSION:To our knowledge, this study provides the first insight into the contribution of wild birds to the dynamics of ESBL-producing E. coli in Tunisia.

Dataset Information

Nationwide high prevalence of CTX-M and an increase of CTX-M-55 in Escherichia coli isolated from patients with community-onset infections in Chinese county hospitals.

Background

Methods

Results

Conclusions

Publications

Nationwide high prevalence of CTX-M and an increase of CTX-M-55 in Escherichia coli isolated from patients with community-onset infections in Chinese county hospitals.

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