scholarly journals Reconciling the potentially irreconcilable? Genotypic and phenotypic amoxicillin-clavulanate resistance in Escherichia coli

2019 ◽  
Author(s):  
Timothy J. Davies ◽  
Nicole Stoesser ◽  
Anna E Sheppard ◽  
Manal Abuoun ◽  
Philip Fowler ◽  
...  
Keyword(s):  
Fixed Effects ◽  
Beta Lactamase ◽  
Beta Lactam ◽  
E Coli ◽  
Reliable Assessment ◽  
Genetic Features ◽  
Amoxicillin Clavulanate ◽  
Agar Dilution ◽  
Phenotypic Methods ◽  
Promoter Mutations

AbstractResistance to amoxicillin-clavulanate, a widely used beta-lactam/beta-lactamase inhibitor combination antibiotic, is rising globally, yet susceptibility testing remains challenging. To test whether whole-genome sequencing (WGS) could provide a more reliable assessment of susceptibility than traditional methods, we predicted resistance from WGS for 976 E. coli bloodstream infection isolates from Oxfordshire, UK, comparing against phenotypes from the BD Phoenix (calibrated against EUCAST guidelines). 339/976 (35%) isolates were amoxicillin-clavulanate resistant. Predictions based solely on beta-lactamase presence/absence performed poorly (sensitivity 23% (78/339)) but improved when genetic features associated with penicillinase hyper-production (e.g. promoter mutations, copy number estimates) were considered (sensitivity 82% (277/339); p<0.0001). Most discrepancies occurred in isolates with peri-breakpoint MICs. We investigated two potential causes; the phenotypic reference and the binary resistant/susceptible classification. We performed reference standard, replicated phenotyping in a random stratified subsample of 261/976 (27%) isolates using agar dilution, following both EUCAST and CLSI guidelines, which use different clavulanate concentrations. As well as disagreeing with each other, neither agar dilution phenotype aligned perfectly with genetic features. A random-effects model investigating associations between genetic features and MICs showed that some genetic features had small, variable and additive effects, resulting in variable resistance classification. Using model fixed-effects to predict MICs for the non-agar dilution isolates, predicted MICs were in essential agreement (±1 doubling dilution) with observed (BD Phoenix) MICs for 691/715 (97%) isolates. This suggests amoxicillin-clavulanate resistance in E. coli is quantitative, rather than qualitative, explaining the poorly reproducible binary (resistant/susceptible) phenotypes and suboptimal concordance between different phenotypic methods and with WGS-based predictions.

scholarly journals Reconciling the Potentially Irreconcilable? Genotypic and Phenotypic Amoxicillin-Clavulanate Resistance in Escherichia coli

2020 ◽  
Vol 64 (6) ◽  
Author(s):  
Timothy J. Davies ◽  
Nicole Stoesser ◽  
Anna E. Sheppard ◽  
Manal Abuoun ◽  
Philip Fowler ◽  
...  
Keyword(s):  
Escherichia Coli ◽  
Fixed Effects ◽  
Beta Lactamase ◽  
Beta Lactam ◽  
Content Type ◽  
Genetic Features ◽  
Amoxicillin Clavulanate ◽  
Doubling Dilution ◽  
Agar Dilution ◽  
Phenotypic Methods

ABSTRACT Resistance to amoxicillin-clavulanate, a widely used beta-lactam/beta-lactamase inhibitor combination antibiotic, is rising globally, and yet susceptibility testing remains challenging. To test whether whole-genome sequencing (WGS) could provide a more reliable assessment of susceptibility than traditional methods, we predicted resistance from WGS for 976 Escherichia coli bloodstream infection isolates from Oxfordshire, United Kingdom, comparing against phenotypes from the BD Phoenix (calibrated against EUCAST guidelines). A total of 339/976 (35%) isolates were amoxicillin-clavulanate resistant. Predictions based solely on beta-lactamase presence/absence performed poorly (sensitivity, 23% [78/339]) but improved when genetic features associated with penicillinase hyperproduction (e.g., promoter mutations and copy number estimates) were considered (sensitivity, 82% [277/339]; P < 0.0001). Most discrepancies occurred in isolates with MICs within ±1 doubling dilution of the breakpoint. We investigated two potential causes: the phenotypic reference and the binary resistant/susceptible classification. We performed reference standard, replicated phenotyping in a random stratified subsample of 261/976 (27%) isolates using agar dilution, following both EUCAST and CLSI guidelines, which use different clavulanate concentrations. As well as disagreeing with each other, neither agar dilution phenotype aligned perfectly with genetic features. A random-effects model investigating associations between genetic features and MICs showed that some genetic features had small, variable and additive effects, resulting in variable resistance classification. Using model fixed-effects to predict MICs for the non-agar dilution isolates, predicted MICs were in essential agreement (±1 doubling dilution) with observed (BD Phoenix) MICs for 691/715 (97%) isolates. This suggests amoxicillin-clavulanate resistance in E. coli is quantitative, rather than qualitative, explaining the poorly reproducible binary (resistant/susceptible) phenotypes and suboptimal concordance between different phenotypic methods and with WGS-based predictions.

scholarly journals Detection of New Delhi Metallo b Lactamase gene in Uropathogenic E. coli

2019 ◽  
Vol 36 (1) ◽  
pp. 29-33
Author(s):  
Sunjukta Ahsan ◽  
Anindita Bhowmik ◽  
Sharmistha Goswami ◽  
Nasir Uddin
Keyword(s):  
Treatment Options ◽  
Pcr Amplification ◽  
Health Concern ◽  
New Delhi ◽  
Beta Lactamase ◽  
Beta Lactam ◽  
E Coli ◽  
Beta Lactam Antibiotics ◽  
Amoxicillin Clavulanate ◽  
Lactamase Gene

The rapid dissemination of antibiotic resistant E. coli is now a worldwide problem. In this study, a total of twenty E. coli obtained from stool were selected to determine resistance to beta lactam antibiotics. Beta–Lactamase are enzymes produced by bacteria that provide multi resistance to beta lactam antibiotics such as penicillin, cephalosporin, cephamycin and carbapenems. Of these isolates (n = 20), 35% were found resistant to Amoxicillin Clavulanate, 5% to Imipenem, 50% to Ceftriaxone and 75% to Ampicillin. PCR amplification confirmed the presence of the New Delhi beta-lactamase gene (blaNDM) in one isolate (5%, n=20). Plasmids of variable sizes were found in all the isolates. Beta lactam antibiotics are now commonly used for the treatment of disease. Resistance of 50% of the isolates to Ceftriaxone is alarming as this indicates that an alternative drug may soon need to replace this antibiotic for successful treatment. The finding of this study is also of public health concern as plasmids were found in most isolates and these mobile genetic elements can be transferred among clinical bacteria, thereby disseminating antibiotic resistance further limiting treatment options. Bangladesh J Microbiol, Volume 36 Number 1 June 2019, pp 29-33

scholarly journals PREVALENCE OF CEPHALOSPORIN-RESISTANT GRAM-NEGATIVE BACILLI FROM CLINICAL SAMPLES

2016 ◽  
pp. 176
Author(s):  
Kavi Aniis ◽  
Rajamanikandan Kcp ◽  
Arvind Prasanth D
Keyword(s):  
Clinical Samples ◽  
Beta Lactamase ◽  
Bacterial Isolates ◽  
Beta Lactam ◽  
Gram Negative ◽  
Beta Lactamases ◽  
Extended Spectrum Beta Lactamase ◽  
E Coli ◽  
Lactam Ring ◽  
Esbl Producers

<p>ABSTRACT<br />Objective: Beta-lactams are the group of antibiotics that contain a ring called as “beta-lactam ring,” which is responsible for the antibacterial activity.<br />The presence of resistance among Gram-negative organisms is due to the production of beta-lactamases enzymes that hydrolysis the beta-lactam ring<br />thereby conferring resistance to the organism. This study is undertaken to determine the prevalence of extended-spectrum beta-lactamase (ESBL)<br />producing Gram-negative organism from clinical samples.<br />Methods: A total of 112 clinical samples were taken for this study. The combined disc synergistic test (CDST) was used for the phenotypic detection<br />of ESBL producers from the clinical samples. The genotypic identification of ESBL producers was carried out by alkaline lysis method by isolation of<br />plasmid DNA.<br />Result: A total of 87 bacterial isolates were isolated and identified. Among them, Klebsiella (41%) was the predominant organism followed by<br />Escherichia coli (33%), Proteus (10%), Pseudomonas (10%), and Serratia (6%). Among the various bacterial isolates, Klebsiella showed a higher<br />percentage of resistance. The CDST showed that 8 isolates of Klebsiella, 3 isolates of E. coli, and 1 isolate of Pseudomonas were found to be ESBL<br />producers. The genotypic confirmation showed that the two bacterial isolates, namely, Klebsiella and E. coli were found to possess temoniera (TEM)<br />gene which was the 400-500 bp conferring resistance to the antibiotics.<br />Conclusion: The results of this study suggest that early detection of ESBL producing Gram-negative organism is a very important step in planning the<br />therapy of patient in Hospitals. CDST continues to be a good indicator in the detection of ESBL producers.<br />Keywords: Beta-lactamases, Gram-negative bacilli, Extended-spectrum beta-lactamase, Resistance, Combined disc synergistic test.</p><p> </p>

scholarly journals SENSITIVITY AND RESISTANCE TO ANTIMICROBIAL AGENTS ESBL-PRODUCING AND NOT PRODUCING ESBL STRAINS OF E. COLI IN PATIENTS WITH URINARY TRACT INFECTION

2019 ◽  
Vol 64 (2) ◽  
pp. 104-110
Author(s):  
N. I. Dimitrova ◽  
T. D. Gasretova ◽  
E. L. Alutina ◽  
G. G. Kharseeva
Keyword(s):  
Urinary Tract ◽  
Antimicrobial Agents ◽  
Beta Lactamase ◽  
Test Results ◽  
Beta Lactams ◽  
Esbl Production ◽  
E Coli ◽  
Amoxicillin Clavulanate ◽  
Resistant Strains ◽  
Tract Infections

As a result of the conducted researches it is shown that 44.1% of urinary tract infections (UTIS) caused by E. coli are accounted for by producers of beta-lactamase of the extended spectrum of action (ESBL). Associated resistance to fluoroquinolones and co-trimoxazole was found in 93.3% of BLRS-producing E. coli strains. All studied strains regardless of ESBL production were sensitive to imipenem, the majority showed sensitivity to ertapenem, gentamicin and resistance to doxycycline. Not producing ESBL strains of E. coli were sensitive to fosfomycin. Comparison of data obtained during testing of isolated cultures on ESBL, study of their sensitivity and resistance to beta-lactams (amoxicillin/clavulanate, ceftazidime, ceftriaxone, cefotaxime, imipenem) indicates the need to test isolates for AmpC products. To this end, during the screening test for ESBL and the method of «double disks», along with cephalosporins of III generation, it is necessary to use a phenotypic test for sensitivity to cefepime. The use of test results of E. coli isolates isolated from patients with UTIS for the production of ESBL, ampC enzymes, carbapenemase and sensitivity to AMP will improve the effectiveness of antimicrobial therapy and will help to curb the formation and spread of antimicrobial-resistant strains.

scholarly journals Detection of extended-spectrum beta-lactamase-producing E. coli and Klebsiella spp. in effluents of different hospitals sewage in Biratnagar, Nepal

2019 ◽  
Vol 12 (1) ◽  
Author(s):  
Sanjay Mahato ◽  
Ajay Mahato ◽  
Elina Pokharel ◽  
Ankita Tamrakar
Keyword(s):  
Multidrug Resistant ◽  
Resistance Pattern ◽  
Beta Lactamase ◽  
Extended Spectrum Beta Lactamase ◽  
E Coli ◽  
Extended Spectrum ◽  
Amoxicillin Clavulanate ◽  
Baseline Information ◽  
Klebsiella Spp

Abstract Objective This study was aimed to determine prevalence and resistance pattern like multidrug resistant (MDR) or ESBL nature of E. coli and Klebsiella spp. from various sewage drain samples with an idea to deliver baseline information that could be utilized for defining guidelines for the treatment of hospital sewages. Results Of 10 sewage samples analyzed, 7 (70%) contained E. coli while 6 (60%) contained Klebsiella. Except one sample, all positive samples contained both E. coli and Klebsiella spp. E. coli isolates were resistant to ampicillin, amoxicillin, cefoxitin, cefuroxime, and cefpodoxime; while 85.7% were resistant to amoxicillin/clavulanate, ceftazidime, cefotaxime and ceftriaxone. 71.4%, 57.1%, 42.9%, and 28.6% were resistant to aztreonam, trimethoprim/sulfamethoxazole, nitrofurantoin, and gentamicin. Most were sensitive to chloramphenicol, ofloxacin, ciprofloxacin, and azithromycin. 85.7% and 57.1% of E. coli were MDR and ESBL isolates, respectively. Klebsiella were resistant to ampicillin, amoxicillin, and amoxicillin/clavulanate. 83.4% of Klebsiella were resistant to cefoxitin. 66.7% of strains were resistant to cefuroxime, ceftazidime, cefotaxime, ceftriaxone, and cefpodoxime. Klebsiella showed 50% resistant to aztreonam and trimethoprim/sulfamethoxazole, while 33.3% were resistant to chloramphenicol, nitrofurantoin, ofloxacin, and ciprofloxacin. Klebsiella were sensitive to azithromycin and gentamicin. 66.7% and 33.3% of Klebsiella were MDR and ESBL isolates, respectively.

scholarly journals MIC and time-kill studies of antipneumococcal activity of GV 118819X (sanfetrinem) compared with those of other agents.

1997 ◽  
Vol 41 (1) ◽  
pp. 148-155 ◽  
Author(s):  
S K Spangler ◽  
M R Jacobs ◽  
P C Appelbaum
Keyword(s):  
United States ◽  
The United States ◽  
Broth Microdilution ◽  
Beta Lactam ◽  
Beta Lactams ◽  
Amoxicillin Clavulanate ◽  
Agar Dilution ◽  
Resistant Strains ◽  
Time Kill

Agar dilution MIC methodology was used to test the activities of GV 118819X (sanfetrinem), ampicillin, amoxicillin, amoxicillin-clavulanate, cefpodoxime, loracarbef, levofloxacin, clarithromycin, ceftriaxone, imipenem, and vancomycin against 53 penicillin-susceptible, 84 penicillin-intermediate and 74 penicillin-resistant pneumococci isolated in the United States. GV 118819X was the most active oral beta-lactam, with MIC at which 50% of the isolates were inhibited (MIC50)/MIC90 values of 0.008/0.03, 0.06/0.5, and 0.5/1.0 micrograms/ml against penicillin-susceptible, -intermediate, and -resistant stains, respectively. Amoxicillin and amoxicillin in the presence of clavulanate (2:1) were the second most-active oral beta-lactams, followed by ampicillin and cefpodoxime; loracarbef was not active against penicillin-intermediate and -resistant strains. Clarithromycin was most active against penicillin-susceptible strains but was less active against intermediate and resistant stains. All pneumococcal stains were inhibited by ceftriaxone and imipenem at MICs of < or = 4.0 and < or = 1.0 micrograms/ml, respectively. The activities of levofloxacin and vancomycin were unaffected by penicillin susceptibility. Time-kill studies of three penicillin-susceptible, three penicillin-intermediate, and three penicillin-resistant pneumococci showed that all compounds, at the broth microdilution MIC, yielded 99.9% killing of all strains after 24 h. Kinetic patterns of all oral beta-lactams, ceftriaxone, and vancomycin were similar relative to the MIC, with 90% killing of all strains first observed after 12 h. However, killing by amoxicillin-clavulanate, imipenem, and levofloxacin was slightly faster and that by clarithromycin was slower than that by the above-described drugs. At 2 x the MIC, more strains were killed earlier than was the case at the MIC, but the pattern seen at the MIC prevailed. When MICs and kill kinetics were combined, sanfetrinem was the most active oral antipneumococcal agent in this study.

Occurrence of beta-lactamase producing Escherichia coli in healthy and diarrhoeic dogs in Andhra Pradesh, India

2018 ◽  
Author(s):  
N. Mohammad Sharif ◽  
B. Sreedevi ◽  
R. K. Chaitanya ◽  
Ch. Srilatha
Keyword(s):  
Escherichia Coli ◽  
Andhra Pradesh ◽  
Diffusion Method ◽  
Beta Lactamase ◽  
Beta Lactam ◽  
Beta Lactams ◽  
Extended Spectrum Beta Lactamase ◽  
E Coli ◽  
Healthy Dogs ◽  
Group 2

The present study was carried out to characterize beta-lactam resistance in Escherichia coli isolated from healthy and diarrhoeic dogs. A total of 93 E. coli were isolated from the rectal swabs of 136 dogs (60/92 of healthy dogs and 33/44 of diarrhoeic dogs). Predominant serotypes detected include rough (19 isolates), O141 (5), O9 (2), O126 (2), O128 (2), O15, O20, O35, O49, O63, O85, O101, O116, O117, O118, O119 (1 isolate each) and the rest of 52 isolates were untypable (UT). Disc diffusion method revealed resistance to cefotaxime (41.9%), ceftriaxone (34.4%), ceftazidime (30.1%) and aztreonam (18.2%). Overall frequency of extended spectrum beta-lactamase (ESBL) phenotype was found to be 29% (27/93). Beta-lactamase genes detected include blaAmpC (86.0%), blaSHV (30.1%), blaCTX-M group-1 (19.3%), blaTEM (17.2%), blaOXA (13.9%) and blaCTX-M group-2 (7.5%). The study revealed resistance to commonly prescribed beta-lactams, with ESBL phenotype in E. coli of canine origin in Andhra Pradesh, India.

scholarly journals Extended-spectrum beta-lactamases producing Escherichia coli and Klebsiella pneumoniaei: A Multi-centric Study Across Karnataka

2014 ◽  
Vol 6 (01) ◽  
pp. 007-013 ◽  
Author(s):  
Sridhar PN Rao ◽  
Prasad Subba Rama ◽  
Vishwanath Gurushanthappa ◽  
Radhakrishna Manipura ◽  
Krishna Srinivasan
Keyword(s):  
Escherichia Coli ◽  
Clinical Isolates ◽  
Beta Lactamase ◽  
Beta Lactam ◽  
Esbl Production ◽  
Beta Lactamases ◽  
E Coli ◽  
Karnataka State ◽  
Extended Spectrum Beta Lactamases ◽  
Esbl Producers

ABSTRACT Background: There are sporadic reports on detection of extended-spectrum beta-lactamases (ESBL) producers from Karnataka; hence, this is a first multicentric study across Karnataka state to determine the prevalence of ESBL production among clinical isolates of Escherichia coli and Klebsiella pneumoniaei. Aims and objectives: To determine the prevalence of ESBL producing clinical isolates of E. coli and K. pneumoniae from five geographically distributed centers across Karnataka, to study the susceptibility of ESBL producing isolates to other beta-lactam and beta-lactam-beta-lactamase inhibitors and to demonstrate transferability of plasmids coding for ESBL phenotype. Materials and Methods: Two hundred isolates of E. coli and K. pneumoniae each were collected from each of the five centers (Bellary, Dharwad, Davangere, Kolar and Mangalore). They were screened for resistance to screening agents (ceftazidime, cefotaxime, ceftriaxone, aztreonam) and positive isolates were confirmed for ESBL production by test described by Clinical and Laboratory Standards Institute . Co-production of ESBL and AmpC beta-lactamase was identified by using amino-phenylboronic acid disk method. Susceptibility of ESBL producers to beta-lactam antibiotics and beta-lactamase inhibitors was performed. Transferability of plasmids was performed by conjugation experiment. Results: Overall prevalence of ESBL production among E. coli and K. pneumoniae across five centers of the state was 57.5%. ESBL production was found to be 61.4% among E. coli and 46.2% among K. pneumoniae. ESBL production was significantly more among E. coli than K. pneumoniae. Significant variations in distribution of ESBL across the state was observed among E. coli isolates, but not among K. pneumoniae isolates. All ESBL producers demonstrated minimum inhibitory concentration levels ≥2 μg/ml towards cefotaxime, ceftazidime and ceftriaxone. Conclusion: Overall prevalence of ESBL production among clinical isolates of E. coli and K. pneumoniae across Karnataka state was high. The prevalence of ESBL production was significantly higher with E. coli than K. pneumoniae isolates. Higher rates of resistance to ceftriaxone and cefotaxime than to ceftazidime suggests the possibility of presence of CTX-M type ESBLs. Of all the beta-lactam/beta-lactamase inhibitor combinations tested, cefepime-tazobactam demonstrated highest in-vitro activity against ESBL producers. There was no statistical difference in the transferability of plasmids among E. coli and K. pneumoniae.

scholarly journals A Statistical Approach for Determination of Disk Diffusion-Based Cutoff Values for Systematic Characterization of Wild-Type and Non-Wild-Type Bacterial Populations in Antimicrobial Susceptibility Testing

2015 ◽  
Vol 53 (6) ◽  
pp. 1812-1822 ◽  
Author(s):  
Giorgia Valsesia ◽  
Malgorzata Roos ◽  
Erik C. Böttger ◽  
Michael Hombach
Keyword(s):  
Resistance Mechanisms ◽  
Beta Lactamase ◽  
Wild Type ◽  
Beta Lactam ◽  
Bacterial Populations ◽  
Content Type ◽  
Extended Spectrum Beta Lactamase ◽  
E Coli

In this study, we introduce a new approach for determination of epidemiologic cutoffs (ECOFFs) and resistant-population cutoffs (RCOFFs) based on receiver operating characteristic (ROC) curves. As an example, the method was applied for determination of ECOFFs for seven different beta-lactam antibiotics and wild-type populations ofEscherichia coli,Klebsiella pneumoniae, andEnterobacter cloacae. In addition, RCOFFs were determined for bacterial populations with defined resistance mechanisms (“resistotypes”), i.e., extended-spectrum beta-lactamase (ESBL)-positiveE. coli, ESBL-positiveK. pneumoniae, and ESBL-positiveE. cloacae; AmpC cephalosporinase-positiveE. coliand AmpC-positiveK. pneumoniae; and broad-spectrum beta-lactamase (BSBL)-positiveE. coli. RCOFFs and ECOFFs are instrumental for a systematic characterization of associations between resistotypes and wild-type populations.

scholarly journals Characterization of Multidrug Resistant Extended-Spectrum Beta-Lactamase-ProducingEscherichia coliamong Uropathogens of Pediatrics in North of Iran

2015 ◽  
Vol 2015 ◽  
pp. 1-7 ◽  
Author(s):  
Mohammad Sadegh Rezai ◽  
Ebrahim Salehifar ◽  
Alireza Rafiei ◽  
Taimour Langaee ◽  
Mohammadreza Rafati ◽  
...  
Keyword(s):  
Antimicrobial Resistance ◽  
Multidrug Resistant ◽  
Beta Lactamase ◽  
Beta Lactam ◽  
Extended Spectrum Beta Lactamase ◽  
E Coli ◽  
Beta Lactam Antibiotics ◽  
Extended Spectrum ◽  
Extended Spectrum Beta Lactamases ◽  
North Of Iran

Escherichia coliremains as one of the most important bacteria causing infections in pediatrics and producing extended-spectrum beta-lactamases (ESBLs) making them resistant to beta-lactam antibiotics. In this study we aimed to genotype ESBL-producingE. coliisolates from pediatric patients for ESBL genes and determine their association with antimicrobial resistance. One hundred of theE. coliisolates were initially considered ESBL producing based on their MIC results. These isolates were then tested by polymerase chain reaction (PCR) for the presence or absence ofCTX,TEM,SHV,GES, andVEBbeta-lactamase genes. About 30.5% of isolatedE. coliwas ESBL-producing strain. TheTEMgene was the most prevalent (49%) followed bySHV(44%),CTX(28%),VEB(8%), andGES(0%) genes. The ESBL-producingE. coliisolates were susceptible to carbapenems (66%) and amikacin (58%) and showed high resistance to cefixime (99%), colistin (82%), and ciprofloxacin (76%). In conclusion, carbapenems were the most effective antibiotics against ESBl-producingE. coliin urinary tract infection in North of Iran. The most prevalent gene is the TEM-type, but the other resistant genes and their antimicrobial resistance are on the rise.

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