A New Colorimetric Method for Rapid Detection of Antibiotic Resistance in Escherichia coli Isolates

Background: The quick diagnosis and early initiation of antibiotic therapy in bacteria-induced infections is of paramount importance. Accordingly, the rapid identification of the causative agent, the short-term results of antibiotic sensitivity, the selection and use of right antibiotics for treatment further highlights the significance of this issue. Objectives: This study aimed to develop a new susceptibility testing method to provide rapid results in Escherichia coli clinical isolates and report the antibiotic susceptibility test results to clinicians in a short period. Methods: In the study, one hundred and ten E. coli clinical isolates were tested. In this regard, antibiotics recommended by the "Clinical and Laboratory Standards Institute (CLSI)" for testing the sensitivity of E. coli isolates, including amoxicillin-clavulanate, cefixime, ceftriaxone, ertapenem, ciprofloxacin, gentamicin, trimethoprim-sulfamethoxazole, and nitrofurantoin were tested. For quality control, E. coli ATCC25922, E. coli ATCC35218, Staphylococcus aureus ATCC29213, and E. coli 13846NTCC strains were used. The broth microdilution method recommended by CLSI was used as the reference method. Minimum inhibitory concentration values were determined, and antimicrobial susceptibilities were then determined according to the “European Committee on Antimicrobial Susceptibility Testing (EUCAST)” criteria. In the next phase, the results of the resazurin microplate method (RMM) were compared. Results: The comparison of the RMM developed in the present study with the reference method revealed that the calculated essential agreement ratios for eight antibiotics varied from 82.72 to 100%, and the categorical agreement values ranged from 95.45 to100%. Conclusions: According to the findings, the RMM results were highly in agreement with the results of the reference method. RMM allows the detection of antibiotic susceptibility quickly (e.g., within 5 hours) as such it is preferred, especially for laboratories with limited facilities. However, further multi-center studies are recommended to use this method in routine laboratories.

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Antibiotic Susceptibility and Genotype Patterns of Escherichia coli, Klebsiella pneumonia and Pseudomonas aeruginosa Isolated from Urinary Tract Infected Patients

Polish Journal of Microbiology ◽

10.33073/pjm-2010-032 ◽

2010 ◽

Vol 59 (3) ◽

pp. 207-212 ◽

Cited By ~ 7

Author(s):

M.I. ABOU-DOBARA ◽

M.A. DEYAB ◽

E.M. ELSAWY ◽

H.H. MOHAMED

Keyword(s):

Escherichia Coli ◽

Pseudomonas Aeruginosa ◽

Urinary Tract ◽

Antibiotic Susceptibility ◽

Susceptibility Testing ◽

Random Amplified Polymorphic Dna ◽

Test Methods ◽

Klebsiella Pneumonia ◽

E Coli ◽

Rapd Pcr

Thirty nine isolates of Escherichia coli, twenty two isolates of Klebsiella pneumoniae and sixteen isolates of Pseudomonas aeruginosa isolated from urinary tract infected patients were analyzed by antimicrobial susceptibility typing and random amplified polymorphic DNA (RAPD)-PCR. Antibiotic susceptibility testing was carried out by microdilution and E Test methods. From the antibiotic susceptibility, ten patterns were recorded (four for E. coli, three for K. pneumoniae and three for P. aeruginosa respectively). Furthermore, genotyping showed seventeen RAPD patterns (seven for E. coli, five for K. pneumoniae and five for P. aeruginosa respectively). In this study, differentiation of strains of E. coli, K. pneumoniae and P. aeruginosa from nosocomial infection was possible with the use of RAPD.

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Antibiotic susceptibility pattern of biofilm forming uropathogenic Escherichia coli isolated from UTI infected patients of Koshi Zonal Hospital in Biratnagar, Nepal

BIBECHANA ◽

10.3126/bibechana.v16i0.19192 ◽

2018 ◽

Vol 16 ◽

pp. 47-54

Author(s):

S Chaudhary ◽

B Khatiwada ◽

N K Chaudhary

Keyword(s):

Escherichia Coli ◽

Antibiotic Susceptibility ◽

Uropathogenic Escherichia Coli ◽

Urine Samples ◽

Resistance Pattern ◽

Isolation And Identification ◽

Antibiotic Susceptibility Pattern ◽

E Coli ◽

Diffusion Technique ◽

Antibiotic Susceptibility Test

Objectives: To investigate the prevalence and antibiotic resistance pattern of biofilm-forming Uropathogenic Escherichia coli (UPEC) from urine samples isolated from UTI infected patients of Koshi zonal hospital, Biratnagar.Methods: A total of 51 urine samples from urinary tract infected patients were collected from Koshi zonal hospital, Biratnagar in the period of July to August 2017. Following the isolation and identification of biofilm-forming uropathogenic Escherichia coli, antibiotic susceptibility test was performed by a modified Kirby-Bauer disc diffusion technique. The biofilm detection was done by Congo red agar method.Results: In the present study, 45% of the urine samples showed a predominant growth of E. coli, among which 70% of isolates exhibited positive biofilm formation. Biofilm forming isolates revealed 100%, 87.5%, 75%, 63% and 12.5% resistant to erythromycin, amoxicillin, cefotaxime, levofloxacin, and nitrofurantoin respectively. Approximately 87.5% of biofilm-forming isolates were found multi-drug resistant.Conclusion: The study revealed the major issue of UTI by E. coli which may be due to poor sanitation, not the proper cleanliness of genitals and unsafe sexual intercourse. Nitrofurantoin and levofloxacin were examined the most effective antibiotics for UPEC. BIBECHANA 16 (2019) 47-54

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Unstable Mechanisms of Resistance to Inhibitors of Escherichia coli Lipoprotein Signal Peptidase

mBio ◽

10.1128/mbio.02018-20 ◽

2020 ◽

Vol 11 (5) ◽

Cited By ~ 1

Author(s):

Homer Pantua ◽

Elizabeth Skippington ◽

Marie-Gabrielle Braun ◽

Cameron L. Noland ◽

Jingyu Diao ◽

...

Keyword(s):

Escherichia Coli ◽

Antibiotic Susceptibility ◽

Pathogenic Bacteria ◽

Susceptibility Testing ◽

Regulatory Elements ◽

Signal Peptidase ◽

Type Ii ◽

Mechanisms Of Resistance ◽

Content Type ◽

E Coli

ABSTRACT Clinical development of antibiotics with novel mechanisms of action to kill pathogenic bacteria is challenging, in part, due to the inevitable emergence of resistance. A phenomenon of potential clinical importance that is broadly overlooked in preclinical development is heteroresistance, an often-unstable phenotype in which subpopulations of bacterial cells show decreased antibiotic susceptibility relative to the dominant population. Here, we describe a new globomycin analog, G0790, with potent activity against the Escherichia coli type II signal peptidase LspA and uncover two novel resistance mechanisms to G0790 in the clinical uropathogenic E. coli strain CFT073. Building on the previous finding that complete deletion of Lpp, the major Gram-negative outer membrane lipoprotein, leads to globomycin resistance, we also find that an unexpectedly modest decrease in Lpp levels mediated by insertion-based disruption of regulatory elements is sufficient to confer G0790 resistance and increase sensitivity to serum killing. In addition, we describe a heteroresistance phenotype mediated by genomic amplifications of lspA that result in increased LspA levels sufficient to overcome inhibition by G0790 in culture. These genomic amplifications are highly unstable and are lost after as few as two subcultures in the absence of G0790, which places amplification-containing resistant strains at high risk of being misclassified as susceptible by routine antimicrobial susceptibility testing. In summary, our study uncovers two vastly different mechanisms of resistance to LspA inhibitors in E. coli and emphasizes the importance of considering the potential impact of unstable and heterogenous phenotypes when developing antibiotics for clinical use. IMPORTANCE Despite increasing evidence suggesting that antibiotic heteroresistance can lead to treatment failure, the significance of this phenomena in the clinic is not well understood, because many clinical antibiotic susceptibility testing approaches lack the resolution needed to reliably classify heteroresistant strains. Here we present G0790, a new globomycin analog and potent inhibitor of the Escherichia coli type II signal peptidase LspA. We demonstrate that in addition to previously known mechanisms of resistance to LspA inhibitors, unstable genomic amplifications containing lspA can lead to modest yet biologically significant increases in LspA protein levels that confer a heteroresistance phenotype.

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Cross-Flow Filtration of Escherichia coli at a Nanofluidic Gap for Fast Immobilization and Antibiotic Susceptibility Testing

Micromachines ◽

10.3390/mi10100691 ◽

2019 ◽

Vol 10 (10) ◽

pp. 691 ◽

Cited By ~ 2

Author(s):

Jan F. Busche ◽

Svenja Möller ◽

Matthias Stehr ◽

Andreas Dietzel

Keyword(s):

Escherichia Coli ◽

Antibiotic Susceptibility ◽

Susceptibility Testing ◽

Cross Flow ◽

Test Time ◽

Microfluidic Chips ◽

Cross Flow Filtration ◽

Antibiotic Susceptibility Test ◽

Flow Filtration ◽

On Chip

Infections with antimicrobial-resistant (AMR) bacteria are globally on the rise. In the future, multi-resistant infections will become one of the major problems in global health care. In order to enable reserve antibiotics to retain their effect as long as possible, broad-spectrum antibiotics must be used sparingly. This can be achieved by a rapid microfluidic phenotypic antibiotic susceptibility test, which provides the information needed for a targeted antibiotic therapy in less time than conventional tests. Such microfluidic tests must cope with a low bacteria concentration. On-chip filtering of the samples to accumulate bacteria can shorten the test time. By means of fluorescence microscopy, we examined a novel nanogap filtration principle to hold back Escherichia coli and to perform cultivation experiments with and without antibiotics present. Microfluidic chips based on the nanogap flow principle showed to be useful for the concentration and cultivation of E. coli. With a concentration of 106 cells/mL, a specific growth rate of 0.013 min−1 and a doubling time of 53 min were achieved. In the presence of an antibiotic, no growth was observed. The results prove that this principle can, in future, be used in fast and marker-free antimicrobial susceptibility testing (AST).

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Isolation, Identification and Antibiotic Susceptibility of Escherichia coli Isolated from Raw Meat from Modake and Ile-Ife, Osun State, Nigeria

Microbiology Research Journal International ◽

10.9734/mrji/2021/v31i830337 ◽

2021 ◽

pp. 9-13

Author(s):

Wilkie Eunice Damilola ◽

Oluduro Anthonia Olufunke ◽

Ezeani Chidinma Vivian ◽

Sotala Toyosi Teniola

Keyword(s):

Escherichia Coli ◽

Antibiotic Resistance ◽

Antibiotic Susceptibility ◽

Multiple Antibiotic Resistance ◽

Raw Meat ◽

E Coli ◽

Antibiotic Susceptibility Test ◽

Mueller Hinton Agar ◽

Meat Samples ◽

High Level

The study reported isolation, identification and antibiotic susceptibility of Escherichia coli isolated from raw meat from Modakeke and Ile-ife, Osun State, Nigeria, with the view to determining the antibiogram profiling of the bacterial isolates. In this study, five samples of fresh meat were collected from different abattoirs in Ile-Ife and Modakeke, Osun State. Isolates of Escherichia coli were isolated, identified morphologically based on their growth on nutrient agar and subjected to antibiotic susceptibility test on Mueller Hinton agar. The mean microbial load from the meat samples ranged from 8.85 x 102cfu/ml to 5.77 x 104cfu/ml. A total of 69 E. coli isolates were recovered from the meat sampled. All the isolates appeared cream, translucent, entire, convex, circular, smooth and glistering. The isolates were identified as Gram negative rods, non-motile, lactose fermenters, positive for indole test and negative for citrate utilization test. All the E. coli isolates were resistant to augmentin, ceftriazone, nitrofurantoin and gentamycin. 98.55% of E. coli isolated was resistant to amoxillin and the least resistant was recorded in ofloxacin (8.70%). However, 91.30% of the E. coli isolates was sensitive to ofloxacin, 81.16% to ciprofloxacin and 36.23% to pefloxacin while none was sensitive to augmentin, ceftriazone, nitrofurantoin and gentamycin. A total of 19 different multiple antibiotic resistance patterns were observed among the isolates. Thirty isolates (43.48%) showed multiple antibiotic resistance to 5 and 10 different antibiotic types each. The study concluded that occurrence of E. coli infection is high in the study area with high level of multiple antibiotic resistance.

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Discrepancy between colistin and polymyxin B susceptibility results among Escherichia coli and Klebsiella pneumoniae clinical isolates

Acta Microbiologica et Immunologica Hungarica ◽

10.1556/030.2021.01458 ◽

2021 ◽

Author(s):

Serap Süzük Yıldız ◽

Can Hüseyin Hekimoğlu ◽

Zekiye Bakkaloğlu ◽

Emine Alp

Keyword(s):

Escherichia Coli ◽

Klebsiella Pneumoniae ◽

Polymyxin B ◽

Multidrug Resistant ◽

Clinical Isolates ◽

Resistant Bacteria ◽

Major Error ◽

E Coli ◽

Microdilution Method ◽

Broth Microdilution Method

AbstractThe selection of therapeutic agent to be used for the treatment of multidrug-resistant bacteria is a major concern. Polymyxin B use has been commenced in Turkey, although its clinical breakpoint is not listed in the EUCAST. This study aimed to determine the correlation between the MIC values of polymyxin B and colistin. A total of 505 isolates, including 122 isolates of Escherichia coli and 383 isolates of Klebsiella pneumoniae were included in the present study. All the isolates were assessed for colistin and polymyxin B using the broth microdilution method. The categorical agreement in the E. coli isolates was 98.4%, and the rate of very major error was 33.3%. The categorical agreement in the K. pneumoniae isolates was 99.5%, the rate of major error was 0.36%, and the rate of very major error was 0.98%. In the evaluation of the essential agreement, 1.6% error in E. coli and 2.3% error in K. pneumoniae were observed. It was concluded that polymyxin B should never be used in the treatment of the isolates reported as colistin-resistant, and if the MIC values are above 4 mg/L in E. coli and K. pneumoniae. Our results indicate importance of reporting both polymyxin B and colistin susceptibility results of clinical isolates.

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Susceptibility of Clinical Isolates of Escherichia coli to Fosfomycin as Measured by Four In Vitro Testing Methods

Journal of Clinical Microbiology ◽

10.1128/jcm.01306-20 ◽

2020 ◽

Vol 58 (10) ◽

Author(s):

James A. Karlowsky ◽

Philippe R. S. Lagacé-Wiens ◽

Nancy M. Laing ◽

Melanie R. Baxter ◽

Heather J. Adam ◽

...

Keyword(s):

Escherichia Coli ◽

Reference Method ◽

Clinical Isolates ◽

Disk Diffusion ◽

Content Type ◽

E Coli ◽

Agar Dilution ◽

Vitek 2 ◽

Urinary Isolates

ABSTRACT Clinical isolates of Escherichia coli (n = 554) were tested against fosfomycin using agar dilution, disk diffusion, and Etest. Agar dilution (reference method) identified few isolates with fosfomycin MICs of 64 (n = 3), 128 (n = 4), and ≥256 μg/ml (n = 2). Applying CLSI (M100, 2020) and EUCAST (v. 10.0, 2020) breakpoints, 98.9% and 98.4% (agar dilution), 99.3% and 99.1% (disk diffusion), and 99.1% and 98.9% (Etest) of isolates were fosfomycin susceptible, respectively. Essential agreement (agar dilution versus Etest) was low (40.8%); 59.3% (131/221) of isolates with agar dilution MICs of 2 to 128 μg/ml tested 2 to 4 doubling dilutions lower by Etest. Applying CLSI breakpoints, categorical agreement was >99% for both disk diffusion and Etest; no major errors (MEs) or very major errors (VMEs) were identified, and rates of minor errors (mEs) were <1%. EUCAST breakpoints yielded categorical agreements of >99% and no MEs for both disk diffusion and Etest; however, VMEs occurred at unacceptable rates of 44.4% (disk diffusion) and 33.3% (Etest). All isolates with agar dilution MICs of ≥32 μg/ml (n = 12) and a subset of isolates with MICs of ≤16 μg/ml (n = 49) were also tested using the Vitek 2 AST-N391 card and generated fosfomycin MICs 1 to ≥3 doubling dilutions lower than agar dilution for 11/12 isolates with agar dilution MICs of ≥32 μg/ml. We conclude that performing fosfomycin disk diffusion or Etest on urinary isolates of E. coli and interpreting results using CLSI breakpoints reliably identified fosfomycin-susceptible isolates regardless of differences in endpoint reading criteria. EUCAST breakpoints generated excessive rates of VMEs for our isolate collection of high fosfomycin susceptibility.

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Identification and Characterization of a Novel FosA7 Member from Fosfomycin-Resistant Escherichia coli Clinical Isolates from Canadian Hospitals

Antimicrobial Agents and Chemotherapy ◽

10.1128/aac.00865-20 ◽

2020 ◽

Vol 65 (1) ◽

pp. e00865-20

Author(s):

Kieran A. Milner ◽

Denice C. Bay ◽

David Alexander ◽

Andrew Walkty ◽

James A. Karlowsky ◽

...

Keyword(s):

Escherichia Coli ◽

Antimicrobial Susceptibility ◽

Susceptibility Testing ◽

Clinical Isolates ◽

Phenotypic Characterization ◽

Content Type ◽

E Coli ◽

Fosfomycin Resistance ◽

Identification And Characterization

ABSTRACTHere, we characterize the fosA genes from three Escherichia coli clinical isolates recovered from Canadian patients. Each fosA sequence was individually overexpressed in E. coli BW25113, and antimicrobial susceptibility testing was performed to assess their role in fosfomycin resistance. The findings from this study identify and functionally characterize FosA3, FosA8, and novel FosA7 members and highlight the importance of phenotypic characterization of fosA genes.

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Evaluation of an ultra-rapid antibiotic susceptibility testing method on positive blood cultures with Escherichia coli

10.1101/2021.12.14.21267046 ◽

2021 ◽

Author(s):

Özden Baltekin ◽

Alexander T. A. Johnsson ◽

Alicia Y. W. Wong ◽

Kajsa Nilsson ◽

Bêrivan Mert ◽

...

Keyword(s):

Escherichia Coli ◽

Rapid Method ◽

Antibiotic Susceptibility ◽

Susceptibility Testing ◽

Blood Stream Infection ◽

Agar Plate ◽

Blood Cultures ◽

Antibiotic Susceptibility Testing ◽

Mortality And Morbidity ◽

E Coli

Blood stream infection (BSI) is related to high mortality and morbidity. Early antimicrobial therapy is crucial in treating patients with BSI. The most common Gram-negative bacteria causing BSI is Escherichia coli. Targeted effective treatment of patients with BSI is only possible if it is based on antibiotic susceptibility testing (AST) data after blood culture positivity. However, there are very few methods available for rapid phenotypic AST and the fastest method takes 4 h. Here we analyzed the performance of a 30 min ultra-rapid method for AST of E. coli directly from positive blood cultures (BC). In total, 51 positive BC with E. coli were studied, and we evaluated the ultra-rapid method directly on positive BC as well as on E. coli colonies cultured on agar plates. The results obtained by the new method were compared with disk diffusion. The method provided accurate AST result in 30 min to Ciprofloxacin and Gentamicin for 92% and 84% of the positive BC samples, respectively. For E. coli isolates retrieved from agar plates, 86% and 96% of the AST results were accurate for Ciprofloxacin and Gentamicin, respectively, after 30 min of assay time. When time to result was modulated in-silico from 30 to 60 minutes for the agar plate samples, accuracy of AST results went up to 92% for Ciprofloxacin and to 100% for Gentamicin. The present study shows that the method is reliable and delivers ultra-rapid AST data in 30 minutes directly from positive BC and as well as from agar plates.

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Antibiotic Susceptibility Pattern of Escherichia coli Isolated from Various Clinical Samples in Duhok City, Kurdistan Region of Iraq

International Journal of Infection ◽

10.5812/iji.103740 ◽

2020 ◽

Vol 7 (3) ◽

Author(s):

Ibrahim A Naqid ◽

Amer A Balatay ◽

Nawfal Rasheed Hussein ◽

Kurdistan Abdullah Saeed ◽

Hiba Abdulaziz Ahmed ◽

...

Keyword(s):

Escherichia Coli ◽

High Resistance ◽

Antibiotic Susceptibility ◽

Bacterial Infections ◽

Antibiotic Sensitivity ◽

Multidrug Resistant ◽

Clinical Isolates ◽

Clinical Samples ◽

Sensitivity Testing ◽

E Coli

Background: Escherichia coli (E. coli) is one of the most common causative agents of bacterial infections. The emergence of multidrug-resistant E. coli is a major public health threat worldwide. Objectives: This study aimed to determine the antibiotic susceptibility profile of clinical isolates of E. coli from different samples. Methods: A total number of 454 clinical samples, including urine, wound, cervical swab, blood, semen, ascetic, and cerebral spinal fluid samples were collected from patients between January 2017 and February 2020. Then, E. coli was confirmed and susceptibility to different antibiotics was determined using the Vitek-2 compact system. Results: Escherichia coli isolates were more frequent in females (70.7%) than in males (29.3%). In the case of urine samples, E. coli was found to be highly susceptible to ertapenem (97.6%) and imipenem (96.4%) but resistant to ampicillin (87.8%). For wound and cervical swabs, E. coli was 100% resistant to ampicillin and cefepime but 100% sensitive to ertapenem and imipenem. It was found that E. coli isolates from blood samples were 100% resistant to ampicillin, ceftriaxone, and cefoxitin, and around 75% of them were sensitive to ertapenem, ciprofloxacin, and levofloxacin. Finally, E. coli isolated from other clinical samples were highly sensitive to ertapenem, imipenem, levofloxacin, nitrofurantoin, and cefazolin. Conclusions: Escherichia coli isolated from various clinical specimens showed differences in antibiotic sensitivity patterns, with high resistance to commonly used antibiotics. The most effective antibiotics against E. coli isolates were ertapenem, imipenem, and nitrofurantoin. However, the clinical isolates of E. coli displayed high resistance rates to ampicillin, ceftriaxone, and cefepime. Therefore, it is proposed to perform antibiotic sensitivity testing by physicians to select the most effective antibiotics.

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