Update From The European Committee On Antimicrobial Suseptibility Testing (EUCAST)

2021 ◽  
Author(s):  
Christian G. Giske ◽  
John Turnidge ◽  
Rafael Cantón ◽  
Gunnar Kahlmeter
Keyword(s):  
Antimicrobial Susceptibility ◽  
Drug Exposure ◽  
Antimicrobial Agents ◽  
Susceptibility Testing ◽  
Critical Role ◽  
Antimicrobial Susceptibility Testing ◽  
Public Consultation ◽  
Diffusion Method ◽  
European Medicines Agency ◽  
European Committee

The European Committee on Antimicrobial Susceptibility Testing (EUCAST) is an international susceptibility testing committee, organized by the European Society for Clinical Microbiology and Infectious Diseases (ESCMID) and functioning as the breakpoint advisory committee of the European Medicines Agency (EMA). The original remit of EUCAST was to harmonize European clinical breakpoints, but very soon the activities expanded beyond the borders of Europe and included newly licensed agents in Europe. Among the milestones were the aggregating of large numbers of MIC distributions, creating a software to display these distributions, the EUCAST concept of identifying epidemiological cut-off values (ECOFF), and the development of a EUCAST disk diffusion method. The EUCAST Development Laboratory has played a critical role in the development of antimicrobial susceptibility testing (AST) methodology including development work for novel antimicrobial agents and for rapid AST directly from blood culture bottles. EUCAST has several standing subcommittees – for AST in fungi (AFST), mycobacteria (AMST) and for microorganisms of veterinary interest (VetCAST), and ad hoc subcommittees on subjects such as anaerobic bacteria, MIC and zone diameter distributions and epidemiological cut off values, the relationship between phenotypic and genotypic resistance, expert rules and methods for the detection of resistance mechanisms. All EUCAST decisions are subjected to the EUCAST public consultation process, the only exception being breakpoints of novel antimicrobial agents where confidentiality agreements during the licensing process prevents public participation. EUCAST has recently revised the definitions of clinical susceptibility interpretive categories S, I and R acknowledging the intimate relationship between drug exposure and susceptibility reporting.

scholarly journals Comparative Study on Effectiveness of Commercial Antibiotic Discs in Federal Capital Territory (FCT), Nigeria

2021 ◽  
pp. 77-83
Author(s):  
Mercy I. Aboh ◽  
Yakubu Ya’aba ◽  
Shehu B. Mohammed ◽  
Peters O. Oladosu
Keyword(s):  
Antimicrobial Susceptibility ◽  
Antimicrobial Agents ◽  
Susceptibility Testing ◽  
Salmonella Typhi ◽  
Antimicrobial Susceptibility Testing ◽  
Diffusion Method ◽  
Klebsiella Pneumonia ◽  
Global Challenge ◽  
Zones Of Inhibition ◽  
Accuracy Of Results

Clinically, antimicrobial susceptibility testing results provide guidance in the choice of antimicrobial agents in patient care. The accuracy of results from antimicrobial susceptibility testing can be affected by multiple factors including the media, antimicrobial discs or preparations, inoculum’s size, plate reading and incubation conditions. Misleading results from antimicrobial susceptibility test leads to the indiscriminate and irrational use of antibiotics and have impacted grossly to the global challenge of antimicrobial resistance. The objectives of this study were to compare the efficacy of different brands of locally and foreign manufactured multi-antibiotic discs on bacteria and assess any significant variation. Two brands each of locally and foreign manufactured multi-antibiotic discs were purchased from retail stores within the FCT. The antibacterial susceptibility of Staphylococcus aureus ATCC 25923, Salmonella typhi ATCC 9150, Klebsiella pneumonia, Pseudomonas aeruginosa, Bacillus subtilis, Escherichia coli ATCC 25922 and Streptococcus pyogenes were carried out using agar diffusion method. There were differences between the diameter zones of inhibition produced by the local brands and the foreign brands of antibiotic discs. Amoxicillin/clavulanic acid (30 µg) disc produced the highest variation within the four brands with zones of inhibition range 12.0 – 20.0 mm against the test organisms. There is need for regulatory bodies like NAFDAC and SON to routinely validate and assess the qualities of these products in the market.

scholarly journals The Frequency of Methicillin-Resistant Staphylococcus aureus and Coagulase Gene Polymorphism in Egypt

2014 ◽  
Vol 2014 ◽  
pp. 1-6 ◽  
Author(s):  
Hend M. Abdulghany ◽  
Rasha M. Khairy
Keyword(s):  
Staphylococcus Aureus ◽  
Gene Polymorphism ◽  
Antimicrobial Susceptibility ◽  
Antimicrobial Agents ◽  
Methicillin Resistant Staphylococcus Aureus ◽  
Susceptibility Testing ◽  
Antimicrobial Susceptibility Testing ◽  
Methicillin Resistant ◽  
Microbiological Methods ◽  
Rflp Typing

The current study aimed to use Coagulase gene polymorphism to identify methicillin-resistant Staphylococcus aureus (MRSA) subtypes isolated from nasal carriers in Minia governorate, Egypt, evaluate the efficiency of these methods in discriminating variable strains, and compare these subtypes with antibiotypes. A total of 400 specimens were collected from nasal carriers in Minia governorate, Egypt, between March 2012 and April 2013. Fifty-eight strains (14.5%) were isolated and identified by standard microbiological methods as MRSA. The identified isolates were tested by Coagulase gene RFLP typing. Out of 58 MRSA isolates 15 coa types were classified, and the amplification products showed multiple bands (1, 2, 3, 4, 5, and 8 bands). Coagulase gene PCR-RFLPs exhibited 10 patterns that ranged from 1 to 8 fragments with AluI digestion. Antimicrobial susceptibility testing with a panel of 8 antimicrobial agents showed 6 different antibiotypes. Antibiotype 1 was the most common phenotype with 82.7%. The results have demonstrated that many new variants of the coa gene are present in Minia, Egypt, different from those reported in the previous studies. So surveillance of MRSA should be continued.

scholarly journals Development of an In-House Rapid Antimicrobial Susceptibility Testing Protocol for Positive Blood Culture and Its Implementation in Routine Microbiology Laboratories

2021 ◽  
Vol 12 ◽  
Author(s):  
Min Cao ◽  
Lin Huang ◽  
Yanyan Hu ◽  
Yinfei Fang ◽  
Rong Zhang ◽  
...  
Keyword(s):  
Blood Culture ◽  
Antimicrobial Susceptibility ◽  
Susceptibility Testing ◽  
Total Error ◽  
Agar Plate ◽  
Error Rates ◽  
Antimicrobial Susceptibility Testing ◽  
Diffusion Method ◽  
High Morbidity ◽  
Clinical Strains

Bloodstream infections (BSI) are associated with high morbidity and mortality and remain a leading cause of death. Blood culture (BC) including the identification and the antimicrobial susceptibility testing of the causative microorganisms should be performed as soon as possible. In this study, we developed an in-house rapid antimicrobial susceptibility testing (rAST) protocol for positive BC. First, the rAST was performed in the simulated positive BC of standard strains (Escherichia coli ATCC 25922, Staphylococcus aureus ATCC 25923, and Pseudomonas aeruginosa ATCC 27853) at three different times to assess the reproducibility and operability by dispensing four drops of BC broth onto a Mueller–Hinton agar plate after a positive signal. Furthermore, the rAST was performed in clinical positive BCs. The results of rAST at 4, 6, 8, and 18 h of incubation were compared with results of the standard 16- to 20-h disk diffusion method, and the preliminary breakpoints of the rAST method were established according to the inhibition diameter of sensitive strains and resistant strains. Finally, the rAST was performed in the simulated positive BC of clinical strains to evaluate the availability of the preliminary breakpoints. The rAST results of standard strains were distributed evenly at three different times. Among the 202 clinical strains used to establish the preliminary breakpoints, the number of zone diameters that could be read and interpreted (60, 87, 98, and 100%) increased with incubation time (4, 6, 8, and 18 h), and the categorical agreement was acceptable, with total error rates of 3.0, 2.3, 2.1, and 1.3% at 4, 6, 8, and 18 h of incubation, respectively. In conclusion, the in-house rAST protocol for positive BC can be implemented in routine laboratories. It provides reliable antimicrobial susceptibility testing results for BSI pathogens after 4–6 h of incubation.

scholarly journals Analysis of Whole-Genome Sequences for the Prediction of Penicillin Resistance and β-Lactamase Activity inBacillus anthracis

mSystems ◽  
2018 ◽  
Vol 3 (6) ◽  
Author(s):  
A. S. Gargis ◽  
H. P. McLaughlin ◽  
A. B. Conley ◽  
C. Lascols ◽  
P. A. Michel ◽  
...  
Keyword(s):  
Sequence Analysis ◽  
Antimicrobial Susceptibility ◽  
Sigma Factor ◽  
Antimicrobial Agents ◽  
Susceptibility Testing ◽  
Antimicrobial Susceptibility Testing ◽  
Penicillin Resistance ◽  
Whole Genome ◽  
Activity Levels ◽  
Content Type

ABSTRACTPenicillin (PEN) is a low-cost option for anthrax treatment, but naturally occurring resistance has been reported. β-Lactamase expression (bla1,bla2) inBacillus anthracisis regulated by a sigma factor (SigP) and its cognate anti-sigma factor (RsiP). Mutations leading to truncation of RsiP were previously described as a basis for PEN resistance. Here, we analyze whole-genome sequencing (WGS) data and compare the chromosomalsigP-bla1regions from 374B. anthracisstrains to determine the frequency of mutations, identify mutations associated with PEN resistance, and evaluate the usefulness of WGS for predicting PEN resistance. Few (3.5%) strains contained at least 1 of 11 different mutations insigP,rsiP, orbla1.Nine of these mutations have not been previously associated with PEN resistance. Four strains showed PEN resistance (PEN-R) by conventional broth microdilution, including 1 strain with a novel frameshift inrsiP. One strain that carries the samersiPframeshift mutation as that found previously in a PEN-R strain showed a PEN-susceptible (PEN-S) phenotype and exhibited decreasedbla1andbla2transcription. An unexpectedly small colony size, a reduced growth rate, and undetectable β-lactamase activity levels (culture supernatant and cell lysate) were observed in this PEN-S strain. Sequence analysis revealed mutations in genes associated with growth defects that may contribute to this phenotype. WhileB. anthracisrsiPmutations cannot be exclusively used to predict resistance, four of the five strains withrsiPmutations were PEN-R. Therefore, theB. anthracissigP-bla1region is a useful locus for WGS-based PEN resistance prediction, but phenotypic testing remains essential.IMPORTANCEDetermination of antimicrobial susceptibility ofB. anthracisis essential for the appropriate distribution of antimicrobial agents for postexposure prophylaxis (PEP) and treatment of anthrax. Analysis of WGS data allows for the rapid detection of mutations in antimicrobial resistance (AMR) genes in an isolate, but the presence of a mutation in an AMR gene does not always accurately predict resistance. As mutations in the anti-sigma factor RsiP have been previously associated with high-level penicillin resistance in a limited number of strains, we investigated WGS assemblies from 374 strains to determine the frequency of mutations and performed functional antimicrobial susceptibility testing. Of the five strains that contained mutations inrsiP, only four were PEN-R by functional antimicrobial susceptibility testing. We conclude that while sequence analysis of this region is useful for AMR prediction inB. anthracis, genetic analysis should not be used exclusively and phenotypic susceptibility testing remains essential.

scholarly journals CIM City: the Game Continues for a Better Carbapenemase Test

2019 ◽  
Vol 57 (7) ◽  
Author(s):  
Romney M. Humphries
Keyword(s):  
Antimicrobial Susceptibility ◽  
Clinical Microbiology ◽  
Susceptibility Testing ◽  
Clinical Care ◽  
Antimicrobial Susceptibility Testing ◽  
European Committee ◽  
Link Type ◽  
Clinical Laboratories ◽  
The Right

ABSTRACT The Clinical and Laboratory Standards Institute and European Committee on Antimicrobial Susceptibility Testing agree that carbapenemase testing is not necessary for clinical care, provided that the laboratory is up to date with current breakpoints. Nonetheless, publication on the development and modification of carbapenemase tests continues, as is the case in this issue of the Journal of Clinical Microbiology (R. W. Beresford and M. Maley, J Clin Microbiol 57:e01852-18, 2019, https://doi.org/10.1128/JCM.01852-18). This commentary explores modifications to the carbapenem inactivation method—but is this the right focus for clinical laboratories?

scholarly journals Point-Counterpoint: Differences between the European Committee on Antimicrobial Susceptibility Testing and Clinical and Laboratory Standards Institute Recommendations for Reporting Antimicrobial Susceptibility Results

2019 ◽  
Vol 57 (9) ◽  
Author(s):  
Gunnar Kahlmeter ◽  
Christian G. Giske ◽  
Thomas J. Kirn ◽  
Susan E. Sharp
Keyword(s):  
Antimicrobial Susceptibility ◽  
Susceptibility Testing ◽  
Antimicrobial Susceptibility Testing ◽  
Test Results ◽  
Diffusion Test ◽  
Disk Diffusion Test ◽  
Technical Variability ◽  
European Committee ◽  
Clinical Laboratories ◽  
Antibiotic Susceptibility Test

INTRODUCTION Antibiotic susceptibility test results are among the most important results issued by clinical microbiology laboratories because they routinely guide critical treatment decisions. Interpretations of MIC or disk diffusion test results, such as “susceptible” or “resistant,” are easily understood. Clinical laboratories also need to determine whether and how their reports will reflect more complex situations. Such situations include, first, whether there is need to administer higher or more frequent doses of antibiotic than usual for clinical efficacy; second, whether an antimicrobial is likely to be effective at a body site where it concentrates; and third, whether there is some uncertainty in the test results due to technical variability that cannot be eliminated. Two leading organizations that set standards for antimicrobial susceptibility testing, the European Committee on Antimicrobial Susceptibility Testing (EUCAST) and the Clinical and Laboratory Standards Institute (CLSI), have taken different strategies to deal with these challenges. In this Point-Counterpoint, Gunnar Kahlmeter and Christian Giske discuss how EUCAST is addressing these issues, and Thomas Kirn and Susan Sharp discuss the CLSI approach.

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