Jove
Visualize
Contact Us
JoVE
x logofacebook logolinkedin logoyoutube logo
ABOUT JoVE
OverviewLeadershipBlogJoVE Help Center
AUTHORS
Publishing ProcessEditorial BoardScope & PoliciesPeer ReviewFAQSubmit
LIBRARIANS
TestimonialsSubscriptionsAccessResourcesLibrary Advisory BoardFAQ
RESEARCH
JoVE JournalMethods CollectionsJoVE Encyclopedia of ExperimentsArchive
EDUCATION
JoVE CoreJoVE BusinessJoVE Science EducationJoVE Lab ManualFaculty Resource CenterFaculty Site
Terms & Conditions of Use
Privacy Policy
Policies

Related Experiment Videos

Errors arising from incorrect orientation of E test strips

J M Hamilton-Miller1, S Shah, T S Yam

  • 1Department of Medical Microbiology, Royal Free Hospital School of Medicine, London, United Kingdom.

Journal of Clinical Microbiology
|July 1, 1995
PubMed
Summary
This summary is machine-generated.

Related Concept Videos

You might also read

Related Articles

Articles linked to this work by shared authors, journal, and citation graph.

Sort by
Same author

The susceptibility of nosocomial pathogens to ceftazidime.

The Journal of antimicrobial chemotherapy·2009
Same author

Activities of ciprofloxacin, levofloxacin, ofloxacin and sparfloxacin against speciated coagulase-negative staphylococci sensitive and resistant to fluoroquinolones.

International journal of antimicrobial agents·2008
Same author

Vancomycin-resistant Staphylococcus aureus: a real and present danger?

Infection·2002
Same author

Identity and antibiotic susceptibility of enterobacterial flora of salad vegetables.

International journal of antimicrobial agents·2001
Same author

Overview of cefixime use in community-acquired infections.

Clinical microbiology and infection : the official publication of the European Society of Clinical Microbiology and Infectious Diseases·2001
Same author

Susceptibility of pneumococci to evernimicin: effect of CO2 and different methodologies.

Clinical microbiology and infection : the official publication of the European Society of Clinical Microbiology and Infectious Diseases·2001
Same journal

Ebola laboratory preparedness at frontline hospitals: can we or can't we?

Journal of clinical microbiology·2026
Same journal

Reporting macrolide-resistant <i>Mycoplasma pneumoniae</i>: a diagnostic obligation?

Journal of clinical microbiology·2026
Same journal

Diagnostic value of HHV-6A/B genotyping in immunocompromised adults.

Journal of clinical microbiology·2026
Same journal

Multicenter performance evaluation of the Simplexa <i>C. auris</i> Direct assay for the detection of <i>Candida auris</i> colonization in bilateral axilla/groin swabs.

Journal of clinical microbiology·2026
Same journal

Comparison of blood culture contamination rates with standard practice versus two blood diversion devices at a single institution.

Journal of clinical microbiology·2026
Same journal

Risk assessment and mitigation of hepatitis C virus RNA carryover contamination in a reflex testing algorithm.

Journal of clinical microbiology·2026
See all related articles

Improperly placed E test strips can lead to inaccurate minimum inhibitory concentration (MIC) results. Always ensure correct orientation for reliable antimicrobial susceptibility testing.

Area of Science:

  • Microbiology
  • Clinical Diagnostics
  • Antimicrobial Resistance

Background:

  • Accurate antimicrobial susceptibility testing (AST) is crucial for guiding patient treatment and combating resistance.
  • E test strips are a common method for determining minimum inhibitory concentrations (MICs).
  • The orientation of testing materials can sometimes impact results in laboratory procedures.

Purpose of the Study:

  • To investigate the impact of incorrect E test strip orientation on MIC determination.
  • To quantify the potential errors introduced by placing E test strips upside down.
  • To compare the effect of orientation on E tests versus conventional disk diffusion methods.

Main Methods:

  • E test strips were intentionally placed upside down and in the correct orientation on agar plates.

Related Experiment Videos

  • Antimicrobial susceptibility testing was performed using standard protocols.
  • Resulting inhibition zones and MICs were compared between the two orientations.

    • Main Results:

    • Placing E test strips upside down frequently resulted in asymmetric or absent inhibition zones.
    • MICs derived from upside-down E tests were consistently and significantly higher than true values.
    • Conventional disk diffusion testing showed no significant impact from disk orientation.

    Conclusions:

    • Incorrect E test strip orientation is a critical error that leads to falsely elevated MICs.
    • This orientation-dependent error is unique to E test strips and not observed with conventional disk diffusion.
    • Strict adherence to correct E test strip placement is essential for accurate AST and effective clinical decision-making.