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

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.

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

2010 ◽  
Vol 59 (3) ◽  
pp. 207-212 ◽  
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.

scholarly journals Antimicrobial resistance pattern of extended-spectrum β-lactamase-producing Escherichia coli isolated from fecal samples of piglets and pig farm workers of selected organized farms of India

2020 ◽  
Vol 13 (2) ◽  
pp. 360-363
Author(s):  
Shikha Tamta ◽  
Obli Rajendran Vinodh Kumar ◽  
Shiv Varan Singh ◽  
Bommenahalli Siddaramiah Pruthvishree ◽  
Ravichandran Karthikeyan ◽  
...  
Keyword(s):  
Escherichia Coli ◽  
Antimicrobial Resistance ◽  
Susceptibility Testing ◽  
Farm Workers ◽  
Resistance Pattern ◽  
Antibiotic Susceptibility Testing ◽  
M Gene ◽  
Fecal Samples ◽  
E Coli ◽  
Pig Farm

Background and Aim: Extended-spectrum β-lactamase (ESBL)-producing Escherichia coli are gradually increasing worldwide and carry a serious public threat. This study aimed to determine the antimicrobial resistance pattern of ESBL-producing E. coli isolated from fecal samples of piglets and pig farm workers. Materials and Methods: Fecal samples from <3-month-old piglets (n=156) and farm workers (n=21) were processed for the isolation of ESBL-producing E. coli in MacConkey agar added with 1 μg/mL of cefotaxime. E. coli (piglets=124; farm workers=21) were tested for ESBL production by combined disk method and ESBL E-strip test. Each of the ESBL-positive isolate was subjected to antibiotic susceptibility testing. The ESBL-producing E. coli were further processed for genotypic confirmation to CTX-M gene. Results: A total of 55 (44.4%, 55/124) and nine (42.9%, 9/21) ESBL-producing E. coli were isolated from piglets and farm workers, respectively. Antibiotic susceptibility testing of the ESBL-positive E. coli isolates from piglets and farm workers showed 100% resistance to ceftazidime, cefotaxime, cefotaxime/clavulanic acid, ceftazidime/clavulanic acid, and cefpodoxime. A proportion of 100% (55/55) and 88.9% (8/9) ESBL-positive E. coli were multidrug resistance (MDR) in piglets and farm workers, respectively. On genotypic screening of the ESBL E. coli isolated from piglets (n=55), 15 were positive for the blaCTX-M gene and of the nine ESBL E. coli from farm workers, none were positive for the blaCTX-M gene. Conclusion: Although there was no significant difference in isolation of ESBL-producing E. coli between piglets and farm workers, the ESBL-positive E. coli from piglets showed relatively higher MDR than farm workers.

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

mBio ◽  
2020 ◽  
Vol 11 (5) ◽  
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.

scholarly journals Rapid antibiotic susceptibility testing on blood cultures using MALDI-TOF MS

PLoS ONE ◽  
2018 ◽  
Vol 13 (10) ◽  
pp. e0205603 ◽  
Author(s):  
Marlène Sauget ◽  
Xavier Bertrand ◽  
Didier Hocquet
Keyword(s):  
Antibiotic Susceptibility ◽  
Susceptibility Testing ◽  
Blood Cultures ◽  
Antibiotic Susceptibility Testing ◽  
Maldi Tof Ms ◽  
Maldi Tof ◽  
Tof Ms

scholarly journals A simple blood-culture bacterial pellet preparation for faster accurate direct bacterial identification and antibiotic susceptibility testing with the VITEK 2 system

2013 ◽  
Vol 62 (5) ◽  
pp. 773-777 ◽  
Author(s):  
Guy Prod’hom ◽  
Christian Durussel ◽  
Gilbert Greub
Keyword(s):  
Ammonium Chloride ◽  
Antibiotic Susceptibility ◽  
Susceptibility Testing ◽  
Blood Cultures ◽  
Correct Identification ◽  
Antibiotic Susceptibility Testing ◽  
Bacterial Identification ◽  
Lower Accuracy ◽  
Direct Inoculation ◽  
Vitek 2

An ammonium chloride procedure was used to prepare a bacterial pellet from positive blood cultures, which was used for direct inoculation of VITEK 2 cards. Correct identification reached 99 % for Enterobacteriaceae and 74 % for staphylococci. For antibiotic susceptibility testing, very major and major errors were 0.1 and 0.3 % for Enterobacteriaceae, and 0.7 and 0.1 % for staphylococci, respectively. Thus, bacterial pellets prepared with ammonium chloride allow direct inoculation of VITEK cards with excellent accuracy for Enterobacteriaceae and a lower accuracy for staphylococci.

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