scholarly journals Overview of Quantitative Methodologies to Understand Antimicrobial Resistance via Minimum Inhibitory Concentration

Animals ◽  
2020 ◽  
Vol 10 (8) ◽  
pp. 1405
Author(s):  
Alec Michael ◽  
Todd Kelman ◽  
Maurice Pitesky
Keyword(s):  
Logistic Regression ◽  
Minimum Inhibitory Concentration ◽  
Antimicrobial Resistance ◽  
Model Selection ◽  
Inhibitory Concentration ◽  
Failure Time ◽  
Resistant Bacteria ◽  
Accelerated Failure Time ◽  
Clinical Resistance ◽  
Interval Censored

The development of antimicrobial resistance (AMR) represents a significant threat to humans and food animals. The use of antimicrobials in human and veterinary medicine may select for resistant bacteria, resulting in increased levels of AMR in these populations. As the threat presented by AMR increases, it becomes critically important to find methods for effectively interpreting minimum inhibitory concentration (MIC) tests. Currently, a wide array of techniques for analyzing these data can be found in the literature, but few guidelines for choosing among them exist. Here, we examine several quantitative techniques for analyzing the results of MIC tests and discuss and summarize various ways to model MIC data. The goal of this review is to propose important considerations for appropriate model selection given the purpose and context of the study. Approaches reviewed include mixture models, logistic regression, cumulative logistic regression, and accelerated failure time–frailty models. Important considerations in model selection include the objective of the study (e.g., modeling MIC creep vs. clinical resistance), degree of censoring in the data (e.g., heavily left/right censored vs. primarily interval censored), and consistency of testing parameters (e.g., same range of concentrations tested for a given antibiotic).

scholarly journals Antimicrobial resistance of Enterococcus faecalis isolated from meat

2015 ◽  
Vol 59 (2) ◽  
pp. 229-233 ◽  
Author(s):  
Hanna Różańska ◽  
Aleksandra Lewtak-Piłat ◽  
Jacek Osek
Keyword(s):  
Minimum Inhibitory Concentration ◽  
Antimicrobial Resistance ◽  
Enterococcus Faecalis ◽  
Inhibitory Concentration ◽  
Poultry Meat ◽  
Erythromycin Resistance ◽  
Concentration Technique

Abstract The aim of the study was the evaluation of the antimicrobial resistance of Enterococcus faecalis strains isolated from cattle, pig, and poultry meat. A test was performed on 111 strains using the minimum inhibitory concentration technique. The highest number of isolates (94 strains) were resistant to lincomycin, the second-highest resistance was to quinupristin/dalfopristin (88 strains), tetracycline followed (65 strains), and erythromycin resistance was also notable (40 strains). All isolates tested were sensitive to daptomycin, nitrofurantoine, and tigecycline, whereas only few strains were resistant to ciprofloxacin, gentamicin, penicillin, and vancomycin. The obtained results showed that meat may be a source of antimicrobial resistant enterococci which may be transferred to humans

scholarly journals Impact of Reappraisal of Fluoroquinolone Minimum Inhibitory Concentration Susceptibility Breakpoints in Gram-Negative Bloodstream Isolates

Antibiotics ◽  
2020 ◽  
Vol 9 (4) ◽  
pp. 189 ◽  
Author(s):  
Stephanie C. Shealy ◽  
Matthew M. Brigmon ◽  
Julie Ann Justo ◽  
P. Brandon Bookstaver ◽  
Joseph Kohn ◽  
...  
Keyword(s):  
Risk Factors ◽  
South Carolina ◽  
Minimum Inhibitory Concentration ◽  
Antimicrobial Resistance ◽  
Inhibitory Concentration ◽  
Clinical Laboratory ◽  
Gram Negative ◽  
Resistance Risk ◽  
Serious Infections ◽  
The Impact

The Clinical Laboratory Standards Institute lowered the fluoroquinolone minimum inhibitory concentration (MIC) susceptibility breakpoints for Enterobacteriaceae and glucose non-fermenting Gram-negative bacilli in January 2019. This retrospective cohort study describes the impact of this reappraisal on ciprofloxacin susceptibility overall and in patients with risk factors for antimicrobial resistance. Gram-negative bloodstream isolates collected from hospitalized adults at Prisma Health-Midlands hospitals in South Carolina, USA, from January 2010 to December 2014 were included. Matched pairs mean difference (MD) with 95% confidence intervals (CI) were calculated to examine the change in ciprofloxacin susceptibility after MIC breakpoint reappraisal. Susceptibility of Enterobacteriaceae to ciprofloxacin declined by 5.2% (95% CI: −6.6, −3.8; p < 0.001) after reappraisal. The largest impact was demonstrated among Pseudomonas aeruginosa bloodstream isolates (MD −7.8, 95% CI: −14.6, −1.1; p = 0.02) despite more conservative revision in ciprofloxacin MIC breakpoints. Among antimicrobial resistance risk factors, fluoroquinolone exposure within the previous 90 days was associated with the largest change in ciprofloxacin susceptibility (MD −9.3, 95% CI: −16.1, −2.6; p = 0.007). Reappraisal of fluoroquinolone MIC breakpoints has a variable impact on the susceptibility of bloodstream isolates by microbiology and patient population. Healthcare systems should be vigilant to systematically adopt this updated recommendation in order to optimize antimicrobial therapy in patients with bloodstream and other serious infections.

scholarly journals Determination of Drug Efflux Pump Efficiency in Drug-Resistant Bacteria Using MALDI-TOF MS

Antibiotics ◽  
2020 ◽  
Vol 9 (10) ◽  
pp. 639 ◽  
Author(s):  
Wen-Jung Lu ◽  
Hsuan-Ju Lin ◽  
Pang-Hung Hsu ◽  
Hong-Ting Victor Lin
Keyword(s):  
Minimum Inhibitory Concentration ◽  
Inhibitory Concentration ◽  
Resistant Bacteria ◽  
Pump Efficiency ◽  
Drug Efflux ◽  
Maldi Tof Ms ◽  
E Coli ◽  
Maldi Tof ◽  
Conventional Methods ◽  
Tof Ms

Multidrug efflux pumps play an essential role in antibiotic resistance. The conventional methods, including minimum inhibitory concentration and fluorescent assays, to monitor transporter efflux activity might have some drawbacks, such as indirect evidence or interference from color molecules. In this study, MALDI-TOF MS use was explored for monitoring drug efflux by a multidrug transporter, and the results were compared for validation with the data from conventional methods. Minimum inhibitory concentration was used first to evaluate the activity of Escherichia coli drug transporter AcrB, and this analysis showed that the E. coli overexpressing AcrB exhibited elevated resistance to various antibiotics and dyes. Fluorescence-based studies indicated that AcrB in E. coli could decrease the accumulation of intracellular dyes and display various efflux rate constants for different dyes, suggesting AcrB’s efflux activity. The MALDI-TOF MS analysis parameters were optimized to maintain a detection accuracy for AcrB’s substrates; furthermore, the MS data showed that E. coli overexpressing AcrB led to increased ions abundancy of various dyes and drugs in the extracellular space at different rates over time, illustrating continuous substrate efflux by AcrB. This study concluded that MALDI-TOF MS is a reliable method that can rapidly determine the drug pump efflux activity for various substrates.

scholarly journals Evaluation of the Sensitivity of Staphylococcus aurous Isolated from Nasal Swabs to Natural Honey

2020 ◽  
pp. 56-64
Author(s):  
A Molanaei ◽  
SA Seyedoshohadaei ◽  
S Hasani ◽  
P Sharifi ◽  
M Rashidian ◽  
...  
Keyword(s):  
Minimum Inhibitory Concentration ◽  
Antibacterial Agents ◽  
Bacterial Resistance ◽  
Inhibitory Concentration ◽  
Antibacterial Properties ◽  
Resistant Bacteria ◽  
Nasal Swabs ◽  
Vancomycin Resistant ◽  
Dilution Tube ◽  
Natural Honey

Introduction: Bacterial resistance to antibacterial agents is a very serious threat to public health. Where some antibacterial agents prove ineffective, the antibacterial properties of honey have been shown to be highly efficacious against several human bacterial pathogens. The purpose of this study is to investigate the sensitivity of Staphylococcus aureus isolated from the nursing staff of a hospital to natural honey. Methods: In this study, 35 strains of methicillin-resistant S. aurous samples were selected from hospital staff's nasal swabs. Two strains were vancomycin-resistant. The serial dilution tube test methodwas used to determine minimum inhibitory concentration (MIC) .The susceptibility of each strain of staph bacteria to natural honey without wax was determined and compared with that of a glucose solution with the same density. Results: In all strains, except for the two strains resistant to vancomycin, MIC level was < 8.3% (v/v). The MIC of glucose as dense as honey was four times higher. The two vancomycin-resistant strains were completely resistant to natural honey. Conclusions: This study has therefore demonstrated that inhibiting bacterial growth is not merely done by purely natural honey not because of osmolality, but vancomycin-resistant bacteria are not sensitive to natural honey. Keywords: sensitivity, Staphylococcus aurous, natural honey, minimum inhibitory concentration

scholarly journals Minimum inhibitory concentration of carbapenems and tigecycline against Salmonella spp.

2009 ◽  
Vol 58 (3) ◽  
pp. 337-341 ◽  
Author(s):  
Malini R. Capoor ◽  
Deepthi Nair ◽  
Jitendra Posti ◽  
Smita Singhal ◽  
Monorama Deb ◽  
...  
Keyword(s):  
Minimum Inhibitory Concentration ◽  
Antimicrobial Resistance ◽  
Final Stage ◽  
Inhibitory Concentration ◽  
Test Strip ◽  
Multidrug Resistant ◽  
Salmonella Spp ◽  
Extended Spectrum ◽  
Agar Dilution

Antimicrobial resistance in Salmonella spp. is of grave concern, more so in quinolone-resistant and extended-spectrum β-lactamase (ESBL)-producing isolates that cause complicated infections. The MIC of azithromycin, ciprofloxacin, cefixime, cefepime, ceftriaxone, gatifloxacin, imipenem, levofloxacin, meropenem and ofloxacin (E-test strip) and tigecycline and faropenem (agar dilution) against 210 Salmonella spp. was determined. MIC90 (defined as the antimicrobial concentration that inhibited growth of 90 % of the strains) of the carbapenems (imipenem and meropenem) for Salmonella Typhi and Salmonella Paratyphi A was 0.064 μg ml−1. MIC90 of faropenem was 0.25 μg ml−1 for S. Typhi, S. Paratyphi A and Salmonella Typhimurium. The MIC90 of azithromycin for all Salmonella spp. ranged from 8 to 16 μg ml−1. Tigecycline showed an MIC90 of 2 μg ml−1 for S. Typhi, 1 μg ml−1 for S. Paratyphi A and 4 μg ml−1 for S. Typhimurium. We concluded that tigecycline and the carbapenems are likely to have roles in the final stage of treatment of quinolone-resistant and ESBL-producing multidrug-resistant salmonellae.

scholarly journals Antimicrobial Resistance and Antimicrobial Use Associated with Laboratory-Confirmed Cases ofCampylobacterInfection in Two Health Units in Ontario

2013 ◽  
Vol 24 (1) ◽  
pp. e16-e21 ◽  
Author(s):  
Anne E Deckert ◽  
Richard J Reid-Smith ◽  
Susan E Tamblyn ◽  
Larry Morrell ◽  
Patrick Seliske ◽  
...  
Keyword(s):  
Minimum Inhibitory Concentration ◽  
Antimicrobial Resistance ◽  
Inhibitory Concentration ◽  
Population Based ◽  
Antimicrobial Treatment ◽  
Antimicrobial Use ◽  
Fecal Culture ◽  
Population Based Study ◽  
Development Of Resistance ◽  
Amoxicillin Clavulanic Acid

AIM: A population-based study was conducted over a two-year period in the Perth District (PD) and Wellington-Dufferin-Guelph (WDG) health units in Ontario to document antimicrobial resistance and antimicrobial use associated with clinical cases of laboratory-confirmed campylobacteriosis.METHODS: Etest (bioMérieux SA, France) was used to determine the minimum inhibitory concentration of amoxicillin/clavulanic acid, ampicillin, chloramphenicol, ciprofloxacin (CIP), clindamycin, erythromycin (ERY), gentamicin, nalidixic acid and tetracycline. Data regarding antimicrobial use were collected from 250 cases.RESULTS: Of the 250 cases, 165 (65.7%) reported staying home or being hospitalized due to campylobacteriosis. Fifty-four per cent of cases (135 of 249) reported taking antimicrobials to treat campylobacteriosis. In 115 cases (51.1%), fecal culture results were not used for treatment decisions because they were not available before the initiation of antimicrobial treatment and/or they were not available before the cessation of symptoms. Of the 250 cases, 124 (49.6%) had availableCampylobacterisolates, of which 66 (53.2%) were resistant to at least one of the antimicrobials tested. No resistance to ampicillin, chloramphenicol or gentamicin was found in these isolates. Six isolates (4.8%) were resistant to CIP. Two isolates (1.6%) were resistant to ERY; however, no isolates were resistant to both CIP and ERY.CONCLUSION: Prudent use practices should be promoted among physicians to reduce the use of antimicrobials for the treatment of gastroenteritis in general and campylobacteriosis in particular, as well as to minimize the future development of resistance to these antimicrobials inCampylobacterspecies.

Sign in / Sign up

Export Citation Format

Share Document