This multicenter study proposes antimicrobial susceptibility mic and disk diffusion methods quality control qc parameters for seven compounds utilized in veterinary health. The kirbybauer disc method this method is also called the agar diffusion method or the disk diffusion method. Test methods in detecting antimicrobial resistance. Lecture 9 antimicrobial susceptibility testing disk. Similarly to the procedure used in diskdiffusion method, the agar plate surface is inoculated by spreading a volume of. Introduction antimicrobial susceptibility test is very important for treating infectious diseases and monitoring antimicrobial resistance in various pathogens. The disk diffusion test, or agar diffusion test, or kirbybauer test disc diffusion antibiotic susceptibility test, disc diffusion antibiotic sensitivity test, kb test, is a test of the antibiotic sensitivity of bacteria. Interpretation should be based on veterinary standards whenever possible, rather than on human medical standards, which may not always be applicable. Generally, an ebook can be downloaded in five minutes or less. Antimicrobial susceptibility testing disk diffusion methods. In order to eliminate or minimize variability in this testing, bauer et al. Compare dilution and diffusion methods and know the basic techniques of agar disk diffusion, broth dilution and agar dilution methods 7. The kirbybauer test for antibiotic susceptibility also called the disc diffusion test is a standard that has been used for years.
On each dish we added the bacteria bacillus subtillus and three antibiotic discs. Pdf the procedure for disk diffusion susceptibility testing has been worked out for rapidly growing nonfastidious bacteria. This is the most thoroughly described disc diffusion method for which. Examples of antibiotic sensitivity testing methods antimicrobial. The clsi qc isolates were tested each time that a set of isolates was evaluated by the two procedures. In contrast, agar dilution and broth microdilution methods are able to overcome some of the limitations of the disk diffusion method. Laboratory manual of standardized methods for antimicrobial sensitivity tests.
Further the depth of the agar in the plate is a factor to be considered in the disc diffusion method. Enumerate the methods used for antimicrobial susceptibility testing ast 6. If no reference is given, it is the procedure used at dvl. Kirbybauer antibiotic sensitivity biology libretexts. Protocol mybook is a cheap paperback edition of the original book and will be sold at uniform, low price. Agar disk diffusion method the testing method most frequently used is the standardized filter paper disk agar diffusion method, also known as the nccls national committee for clinical laboratory standards or kirbybauer method. Agar diffusion methods employing dried filter paper disks impregnated with specific concentrations of antimicrobial agents were developed in the 1940s. These include the enterobacteriaceae, staphylococcus spp. Antifungal susceptibility testing of dermatophytes by agar. Because of convenience, efficiency and cost, the disk diffusion method is probably the most widely used. This procedure involved preparing twofold dilutions of antibiotics eg, 1, 2, 4, 8, and. Disk diffusion is based on the determination of an inhibition zone. Thus, a varied range of natural products of plant, fungi and lichen origin were tested against two bacterial species, staphylococcus aureus atcc 25923 and escherichia coli atcc 25922, by two variants of the agar diffusion.
Laboratory methods for assessing the susceptibility of an organism to such drugs vary. Comparison between disk diffusion and microdilution. Comparison of disk diffusion, agar dilution, and broth. The bacterial isolate the antibiotics the standard operating procedures sop dr.
Of particular importance is the concept of efficacy ratios. Learn vocabulary, terms, and more with flashcards, games, and other study tools. The result was a standardized procedure for the disk diffusion. Broadly, they fall into two groupsdisc diffusion tests and dilution tests. Antibacterial screening methods for evaluation of natural. Inoculate the plate with the test organism by streaking the swab in a backandforth motion very close together as you move across and down the plate. Disk diffusion susceptibility methods are simple and costeffective and highlight different features of the patterns of in vitro response in ways that can be instructive. Zone sizes and minimal inhibitory concentrations mic by agar dilution were interpreted using the ranges in the nccls tables for organisms other than. These discs are used for semiquantitative in vitro susceptibility testing by the agar disc diffusion test procedure of common, rapidly growing and certain fastidious bacterial pathogens. Evaluation of disk diffusion method for determining posaconazole susceptibility of filamentous fungi. Testing an antibiotic using a disk diffusion assay kirby bauer method duration. The kirbybauer test for antibiotic susceptibility, called the disc diffusion test, is a standard that has been used for years. A disk diffusion method for testing yeasts has been developed.
The majority of in vitro work with them to date has been with brothbased methods, and there are few reports of testing by a disk diffusion based procedure 1, 3, 4. Bauer, then standardized by the world health organization in 1961. Kirbybauer disk diffusion susceptibility test protocol, inoculation of the muellerhinton agar plate. The agar used is meullerhinton agar that is rigorously tested for composition and ph. Among these available tests, the two most commonly used methods in veterinary laboratories are the agar disk diffusion method and the broth microdilution method.
Disc diffusion or the kirbybauer test is one of the classic microbiology techniques, and it is still very commonly used. Because of convenience, efficiency, and cost, the disc diffusion. This content was downloaded from seafdecaqd institutional repository sair the official. Kirbybauer disk diffusion susceptibility test protocol asm.
The disk diffusion test, or agar diffusion test, or kirbybauer test is a test of the antibiotic. All aspects of the kirbybauer procedure are standardized to ensure consistent and accurate. The media and reagents are available from several companies including oxoid, merck and difco. It uses antibiotic discs to test the extent to which bacteria are affected by those antibiotics. A procedure similar to broth dilution is agar dilution. The agar based disk diffusion abdd susceptibility method for dermatophytes is quick, easy and a good option matar et al. Who global foodborne infections network laboratory subcommittee. Agar well diffusion method is widely used to evaluate the antimicrobial activity of plants or microbial extracts. Professor ahmed khan quiz 4 ch 20 disinfectants study guide by alexrose95 includes 16 questions covering vocabulary, terms and more. However data on disk diffusion methods for dermatophytes are scarce esteban et al. Kirbybauer disk diffusion susceptibility test protocol. A disk diffusion method to test yeasts has recently been standardised nccls, 2004.
Quality control guidelines for disk diffusion and broth. In this test, a number of small, sterile filter paper disks of uniform size 6 mm that have each been impregnated with a defined concentration of an antimicrobial. Methods of using control data to monitor the performance. The procedure followed is simply that a filter disk impregnated with an antibiotic is applied to the surface of an agar plate containing the organism to be tested and the plate is incubated at 37c for 2448 hours. Disk diffusion testing has served as such an example for antibacterial testing see clsi document m023, and therefore, the clsi subcommittee on antifungal susceptibility tests has developed recommendations for disk diffusion testing for antifungal agents. A stock solution of extract was prepared by dissolving 0. The disk diffusion method is performed using muellerhinton agar mha, which. Disc diffusion method was used for antibacterial activity. The procedure followed is simply that a filter disk impregnated with an antibiotic is applied to the surface of an agar plate containing the organism to. Alexomycin, apramycin, tiamulin, tilmicosin, and tylosin were tested by broth microdilution against various national committee for clinical laboratory standards ncclsrecommended qc organisms staphylococcus. Quality assurance of antimicrobial susceptibility testing. Pdf on the theory of the disk diffusion test researchgate.
Verification of antimicrobial susceptibility testing methods a practical approach publication. Similarly to the procedure used in disk diffusion method, the agar plate surface is inoculated by spreading a volume of the microbial inoculum over the entire agar surface. Have detailed theoretical knowledge on how to perform the main methods in a laboratory 8. This prompted the development of a disk diffusion procedure for the determination of susceptibility of bacteria to antimicrobials.
A comparison of disc diffusion and microbroth dilution. Bsac disc diffusion method for antimicrobial susceptibility testing. Sensititre is customizable with a choice of completely automated, semiautomated, or manual equipment. In class we prepared petri dishes following the kirbybauer disk diffusion method.
The susceptibilities to penicillin, tetracycline, erythromycin, gentamicin, vancomycin and teicoplanin of 58 strains of corynebacterium jeikeium were assessed by disk diffusion and agar dilution reference methods. Besides, similar to other agarbased methods, disk diffusion is laborintensive and timeconsuming klancnik et al. First developed in the 1950s, it was refined and by w. Disk diffusion kirbybauer method flashcards quizlet. It is essential that the reports are relevant, timely interpreted correctly to ensure quality control. Disk diffusionbased methods for determining candida. In this document, we attempt to answer many of the frequently asked questions regarding antimicrobial susceptibility testing. Kirby bauer method and the liquid media based microbroth dilution method. The disk diffusion susceptibility method 2, 11, 12 is simple and practical and has been wellstandardized.
Download fulltext pdf download fulltext pdf download fulltext pdf standardisation of disk diffusion results for antibiotic susceptibility testing using the sirscan automated zone reader. Asmscience kirbybauer disk diffusion susceptibility. Disk diffusion by the kirbybauer method is a standardized technique for testing rapidly growing. Determination of mic by agar diffusion method youtube.