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

Penicillin susceptibility testing of gonococci by disc diffusion.

M R Jacobs, J F Tomashefski, A Franco

    The Journal of Antimicrobial Chemotherapy
    |April 1, 1981
    PubMed
    Summary

    This study identifies optimal beta-lactam discs for detecting penicillin resistance in bacterial strains. Specific penicillin and methicillin disc concentrations and cut-off zones effectively differentiate sensitive, intermediate, and resistant strains.

    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

    Short communication: Prevalence of Staphylococcus aureus and methicillin-resistant S. aureus in bulk tank milk from dairy goat farms in Northern Italy.

    Journal of dairy science·2015
    Same author

    Volatile compared with total intravenous anaesthesia in patients undergoing high-risk cardiac surgery: a randomized multicentre study.

    British journal of anaesthesia·2014
    Same author

    Integrated care pathways for airway diseases (AIRWAYS-ICPs).

    The European respiratory journal·2014
    Same author

    Adaptation of the chronic disease self-management program for cancer survivors: feasibility, acceptability, and lessons for implementation.

    Journal of cancer education : the official journal of the American Association for Cancer Education·2014
    Same author

    Induction of interleukin-8 and interleukin-12 in neonatal ovine lung following experimental inoculation of bovine respiratory syncytial virus.

    Journal of comparative pathology·2014
    Same author

    Linking food web functioning and habitat diversity for an ecosystem based management: a Mediterranean lagoon case-study.

    Marine environmental research·2014

    Area of Science:

    • Microbiology
    • Clinical Diagnostics
    • Antimicrobial Resistance

    Background:

    • Accurate detection of bacterial susceptibility to antibiotics is crucial for effective treatment.
    • Penicillin resistance is a growing concern, necessitating reliable diagnostic methods.
    • Beta-lactam discs are commonly used for antimicrobial susceptibility testing.

    Purpose of the Study:

    • To evaluate the efficacy of various beta-lactam discs in differentiating penicillin-sensitive, intermediate-resistant, and resistant bacterial strains.
    • To determine optimal disc concentrations and zone diameter cut-offs for accurate susceptibility classification.
    • To assess the utility of penicillin, methicillin, and oxacillin discs.

    Main Methods:

    • Investigated the performance of different beta-lactam discs against bacterial strains with known minimal inhibitory concentrations (MICs) of penicillin G.

    Related Experiment Videos

  • Determined zone diameters for various disc concentrations (0.15 µg and 0.6 µg penicillin G, 5 µg methicillin, 1 µg oxacillin).
  • Established cut-off zone diameters to categorize strains into sensitive, intermediate, and resistant groups.

    • Main Results:

    • 0.15 µg and 0.6 µg penicillin G discs, and 5 µg methicillin discs were most effective in separating the three susceptibility groups.
    • Specific cut-off zones were defined: 12/24 mm for 0.15 µg penicillin, 24/32 mm for 0.6 µg penicillin, and 20/30 mm for 5 µg methicillin.
    • 1 µg oxacillin discs distinguished resistant from sensitive/intermediate strains at an 8 mm cut-off.

    Conclusions:

    • A combination of at least two different beta-lactam discs provides the most reliable assessment of bacterial susceptibility to penicillin.
    • The identified disc concentrations and cut-off zones offer a practical approach for routine antimicrobial susceptibility testing.
    • Optimized disc selection enhances the accuracy of classifying bacterial resistance patterns.