(84 days)
Not Found
No
The description focuses on a standard microdilution technique and automated reading of growth, with no mention of AI or ML for interpretation or analysis.
No.
The device is described as an in vitro test to determine the susceptibility of microorganisms to antimicrobial agents, functioning as a "laboratory aid in the determination of in vitro susceptibility to antimicrobial agents." It does not directly treat or diagnose a patient's condition.
Yes
The "Intended Use / Indications for Use" section explicitly states that the device is "designed for antimicrobial susceptibility testing of Gram positive microorganisms and is intended for use with the VITEK® 2 and VITEK® 2 Compact Systems as a laboratory aid in the determination of in vitro susceptibility to antimicrobial agents." This indicates its role in identifying the susceptibility of microorganisms to antimicrobial agents, which is a diagnostic function.
No
The device description clearly states it is an "AST card" which is a physical component containing wells with premeasured antibiotic and culture media. It is used with the VITEK® 2 Systems, which are instruments that fill, seal, incubate, and read the cards. This involves significant hardware components.
Yes, this device is an IVD (In Vitro Diagnostic).
Here's why:
- Intended Use: The "Intended Use / Indications for Use" section explicitly states that the device is "designed for antimicrobial susceptibility testing of Gram positive microorganisms" and is intended for use "as a laboratory aid in the determination of in vitro susceptibility to antimicrobial agents." The phrase "in vitro" is a key indicator of an IVD.
- Device Description: The description details a test performed on a sample (bacterial isolate) outside of the body, using a specific card with premeasured reagents and culture media. This is characteristic of an in vitro test.
- Clinical Laboratories: The "Intended User / Care Setting" is listed as "clinical laboratories," which are the typical settings where IVDs are used for diagnostic purposes.
- Performance Studies: The description of performance studies involves comparing the device's performance to a reference method (CLSI broth microdilution) using clinical isolates. This type of validation is standard for IVDs.
- Key Metrics: The key metrics reported (Essential Agreement, Category Agreement, Errors) are standard performance measures used to evaluate the accuracy and reliability of IVDs for susceptibility testing.
All of these points strongly indicate that the VITEK® 2 AST-Gram Positive Lefamulin is an In Vitro Diagnostic device.
N/A
Intended Use / Indications for Use
VITEK® 2 AST-Gram Positive Lefamulin is designed for antimicrobial susceptibility testing of Gram positive microorganisms and is intended for use with the VITEK® 2 and VITEK® 2 Compact Systems as a laboratory aid in the determination of in vitro susceptibility to antimicrobial agents.
VITEK® 2 AST-Gram Positive Lefamulin is a quantitative test. Lefamulin has been shown to be active against most strains of the microorganisms listed below, according to the FDA label for this antimicrobial.
Active both in vitro and in clinical infections: Staphylococcus aureus (methicillin-susceptible isolates)
The VITEK® 2 Gram-positive Susceptibility Card is intended for use with the VITEK® 2 Systems in clinical laboratories as an in vitro test to determine the susceptibility of Staphylococcus spp., and S. agalactive to antimicrobial agents when used as instructed.
Product codes
LON, LTT, LTW
Device Description
The principle of the VITEK® 2 AST cards is based on the microdilution minimum inhibitory concentration (MIC) technique reported by MacLowry and Marsh (1) and Gerlach (2). The VITEK® 2 AST card is essentially a miniaturized, abbreviated and automated version of the doubling dilution technique (0).
Each VITEK® 2 AST card contains 64 wells. A control well which only contains microbiological culture media is resident on all cards. The remaining wells contain premeasured portions of a specific antibiotic combined with culture media. The bacterial or yeast isolate to be tested is diluted to a standardized concentration with 0.45 - 0.5% saline before being used to rehydrate the antimicrobial medium within the card. The VITEK® 2 System automatically fills, seals and places the card into the incubator/reader. The VITEK® 2 Compact has a manual filling, sealing and loading operation. The VITEK® 2 Systems monitor the growth of each well in the card over a defined period of time. At the completion of the incubation cycle, a report is generated that contains the MIC value along with the interpretive category result for each antibiotic contained on the card.
VITEK® 2 AST-GP Lefamulin (≤ 0.03 –>4 µg/mL) has the following concentrations in the card: 0.125, 0.5, 1, and 2 (equivalent standard method concentration by efficacy in ug/mL).
Mentions image processing
Not Found
Mentions AI, DNN, or ML
Not Found
Input Imaging Modality
Not Found
Anatomical Site
Not Found
Indicated Patient Age Range
Not Found
Intended User / Care Setting
Clinical laboratories
Description of the training set, sample size, data source, and annotation protocol
Not Found
Description of the test set, sample size, data source, and annotation protocol
An external evaluation was conducted with fresh and stock clinical isolates, as well as a set of challenge strains. The external evaluations were designed to confirm the acceptability of VITEK® 2 AST-GP Lefamulin by comparing its performance with the CLSI broth microdilution reference method incubated at 16-20 hrs.
Summary of Performance Studies (study type, sample size, AUC, MRMC, standalone performance, key results)
Study Type: Performance data from an external evaluation
Sample Size: 404 isolates tested.
Key Results:
- Essential Agreement (EA) for Lefamulin: (367/404) 90.8%
- Category Agreement (CA) for Lefamulin: (403/404) 99.8%
- Very Major Error (VME): (0/3) 0.0%
- Major Error (ME): (1/401) 0.2%
- Minor Error (mE): Not applicable (N/A)
- Reproducibility: 100.0%
- VITEK® 2 Lefamulin MIC values tended to be in exact agreement or at least one doubling dilution lower when testing methicillin-susceptible S. aureus compared to the CLSI reference method, broth microdilution.
- The incubation time (Time of Call) for AST GP cards containing Lefamulin may exceed 16 hours. This extended incubation time is required to generate MIC values.
- Reproducibility and Quality Control demonstrated acceptable results.
Key Metrics (Sensitivity, Specificity, PPV, NPV, etc.)
Essential Agreement (EA) %
Category Agreement (CA) %
Very Major Error (VME) %
Major Error (ME) %
Minor Error (mE) %
Reproducibility %
Predicate Device(s)
Reference Device(s)
Not Found
Predetermined Change Control Plan (PCCP) - All Relevant Information
Not Found
§ 866.1645 Fully automated short-term incubation cycle antimicrobial susceptibility system.
(a)
Identification. A fully automated short-term incubation cycle antimicrobial susceptibility system is a device that incorporates concentrations of antimicrobial agents into a system for the purpose of determining in vitro susceptibility of bacterial pathogens isolated from clinical specimens. Test results obtained from short-term (less than 16 hours) incubation are used to determine the antimicrobial agent of choice to treat bacterial diseases.(b)
Classification. Class II (special controls). The special control for this device is FDA's guidance document entitled “Class II Special Controls Guidance Document: Antimicrobial Susceptibility Test (AST) Systems; Guidance for Industry and FDA.”
0
Image /page/0/Picture/0 description: The image contains the logos of the Department of Health and Human Services and the Food and Drug Administration (FDA). The Department of Health and Human Services logo is on the left, and the FDA logo is on the right. The FDA logo includes the letters "FDA" in a blue square, followed by the words "U.S. FOOD & DRUG ADMINISTRATION" in blue text.
March 11, 2024
bioMerieux, Inc. Anne Rasponi Senior Regulatory Affairs Specialist 595 Anglum Road Hazelwood, Missouri 63042
Re: K234000
Trade/Device Name: VITEK 2 AST-Gram Positive Lefamulin (=4 ug/mL) Regulation Number: 21 CFR 866.1645 Regulation Name: Fully Automated Short-Term Incubation Cycle Antimicrobial Susceptibility System Regulatory Class: Class II Product Code: LON, LTT, LTW Dated: December 15, 2023 Received: December 18, 2023
Dear Anne Rasponi:
We have reviewed your section 510(k) premarket notification of intent to market the device referenced above and have determined the device is substantially equivalent (for the indications for use stated in the enclosure) to legally marketed predicate devices marketed in interstate commerce prior to May 28, 1976, the enactment date of the Medical Device Amendments, or to devices that have been reclassified in accordance with the provisions of the Federal Food, Drug, and Cosmetic Act (the Act) that do not require approval of a premarket approval application (PMA). You may, therefore, market the device, subject to the general controls provisions of the Act. Although this letter refers to your product as a device, please be aware that some cleared products may instead be combination products. The 510(k) Premarket Notification Database available at https://www.accessdata.fda.gov/scripts/cdrh/cfdocs/cfpmn/pmn.cfm identifies combination product submissions. The general controls provisions of the Act include requirements for annual registration, listing of devices, good manufacturing practice, labeling, and prohibitions against misbranding and adulteration. Please note: CDRH does not evaluate information related to contract liability warranties. We remind you, however, that device labeling must be truthful and not misleading.
If your device is classified (see above) into either class II (Special Controls) or class III (PMA), it may be subject to additional controls. Existing major regulations affecting your device can be found in the Code of Federal Regulations, Title 21, Parts 800 to 898. In addition, FDA may publish further announcements concerning your device in the Federal Register.
Additional information about changes that may require a new premarket notification are provided in the FDA guidance documents entitled "Deciding When to Submit a 510(k) for a Change to an Existing Device" (https://www.fda.gov/media/99812/download) and "Deciding When to Submit a 510(k) for a Software Change to an Existing Device" (https://www.fda.gov/media/99785/download).
1
Your device is also subject to, among other requirements, the Quality System (QS) regulation (21 CFR Part 820), which includes, but is not limited to, 21 CFR 820.30, Design controls; 21 CFR 820.90, Nonconforming product; and 21 CFR 820.100, Corrective and preventive action. Please note that regardless of whether a change requires premarket review. the OS regulation requires device manufacturers to review and approve changes to device design and production (21 CFR 820.30 and 21 CFR 820.70) and document changes and approvals in the device master record (21 CFR 820.181).
Please be advised that FDA's issuance of a substantial equivalence determination does not mean that FDA has made a determination that your device complies with other requirements of the Act or any Federal statutes and regulations administered by other Federal agencies. You must comply with all the Act's requirements, including, but not limited to: registration and listing (21 CFR Part 807); labeling (21 CFR Part 801 and Part 809); medical device reporting of medical device-related adverse events) (21 CFR Part 803) for devices or postmarketing safety reporting (21 CFR Part 4, Subpart B) for combination products (see https://www.fda.gov/combination-products/guidance-regulatory-information/postmarketing-safetyreporting-combination-products); good manufacturing practice requirements as set forth in the quality systems (OS) regulation (21 CFR Part 820) for devices or current good manufacturing practices (21 CFR Part 4, Subpart A) for combination products; and, if applicable, the electronic product radiation control provisions (Sections 531-542 of the Act); 21 CFR Parts 1000-1050.
Also, please note the regulation entitled, "Misbranding by reference to premarket notification" (21 CFR 807.97). For questions regarding the reporting of adverse events under the MDR regulation (21 CFR Part 803), please go to https://www.fda.gov/medical-device-safety/medical-device-reportingmdr-how-report-medical-device-problems.
For comprehensive regulatory information about mediation-emitting products, including information about labeling regulations, please see Device Advice (https://www.fda.gov/medicaldevices/device-advice-comprehensive-regulatory-assistance) and CDRH Learn (https://www.fda.gov/training-and-continuing-education/cdrh-learn). Additionally, you may contact the Division of Industry and Consumer Education (DICE) to ask a question about a specific regulatory topic. See the DICE website (https://www.fda.gov/medical-device-advice-comprehensive-regulatoryassistance/contact-us-division-industry-and-consumer-education-dice) for more information or contact DICE by email (DICE@fda.hhs.gov) or phone (1-800-638-2041 or 301-796-7100).
Sincerely,
Natasha Grif
Natasha Griffin O.B.O. Ribhi Shawar, Ph.D. (ABMM) Branch Chief, General Bacteriology and Antimicrobial Susceptibility Branch Division of Microbiology Devices OHT7: Office of In Vitro Diagnostics Office of Product Evaluation and Quality Center for Devices and Radiological Health
2
Indications for Use
510(k) Number (if known)
Device Name
VITEK 2 AST-Gram Positive Lefamulin (≤0.03 - ≥4 µg/ml)
Indications for Use (Describe)
VITEK® 2 AST-Gram Positive Lefamulin is designed for antimicrobial susceptibility testing of Gram positive microorganisms and is intended for use with the VITEK® 2 and VITEK® 2 Compact Systems as a laboratory aid in the determination of in vitro susceptibility to antimicrobial agents.
VITEK® 2 AST-Gram Positive Lefamulin is a quantitative test. Lefamulin has been shown to be active against most strains of the microorganisms listed below, according to the FDA label for this antimicrobial.
Active both in vitro and in clinical infections: Staphylococcus aureus (methicillin-susceptible isolates)
The VITEK® 2 Gram-positive Susceptibility Card is intended for use with the VITEK® 2 Systems in clinical laboratories as an in vitro test to determine the susceptibility of Staphylococcus spp., and S. agalactive to antimicrobial agents when used as instructed.
Type of Use (Select one or both, as applicable)X Prescription Use (Part 21 CFR 801 Subpart D)
Over-The-Counter Use (21 CFR 801 Subpart C)
CONTINUE ON A SEPARATE PAGE IF NEEDED.
This section applies only to requirements of the Paperwork Reduction Act of 1995.
DO NOT SEND YOUR COMPLETED FORM TO THE PRA STAFF EMAIL ADDRESS BELOW.
The burden time for this collection of information is estimated to average 79 hours per response, including the time to review instructions, search existing data sources, gather and maintain the data needed and complete and review the collection of information. Send comments regarding this burden estimate or any other aspect of this information collection, including suggestions for reducing this burden, to:
Department of Health and Human Services Food and Drug Administration Office of Chief Information Officer Paperwork Reduction Act (PRA) Staff PRAStaff@fda.hhs.gov
"An agency may not conduct or sponsor, and a person is not required to respond to, a collection of information unless it displays a currently valid OMB number."
3
510(k) SUMMARY
VITEK® 2 AST-GP Lefamulin (≤ 0.03 ->4 µg/mL)
A. 510(k) Submission Information:
| Submitter's Name: | bioMérieux, Inc. | |
|---|---|---|
| Address: | 595 Anglum Road | |
| Hazelwood, MO 63042 | ||
| Contact Person: | Anne Rasponi | |
| Regulatory Affairs Specialist | ||
| Phone Number: | 314-506-8223 | |
| Fax Number: | 314-731-8689 | |
| Date of Preparation: | December 15, 2023 | |
| B. Device Name: | ||
| Formal/Trade Name: | VITEK® 2 AST-Gram-Positive Lefamulin (≤ 0.03 - ≥4 | |
| µg/mL) | ||
| Classification Name: | 21 CFR 866.1645 | |
| Fully Automated Short-Term Incubation Cycle | ||
| Antimicrobial Susceptibility System | ||
| Product Code LON, LTT, LTW | ||
| Common Name: | VITEK® 2 AST-GP Lefamulin | |
| C. Predicate Device: | ||
| VITEK® 2 AST-GP Daptomycin (≤0.12 - ≥8 µg/mL) | ||
| (K230864) |
D. Device Description:
The principle of the VITEK® 2 AST cards is based on the microdilution minimum inhibitory concentration (MIC) technique reported by MacLowry and Marsh (1) and Gerlach (2). The VITEK® 2 AST card is essentially a miniaturized, abbreviated and automated version of the doubling dilution technique (0).
Each VITEK® 2 AST card contains 64 wells. A control well which only contains microbiological culture media is resident on all cards. The remaining wells contain premeasured portions of a specific antibiotic combined with culture media. The bacterial or yeast isolate to be tested is diluted to a standardized concentration with 0.45 - 0.5% saline before being used to rehydrate the antimicrobial medium within the card. The VITEK® 2 System automatically fills, seals and places the card into the incubator/reader. The VITEK® 2 Compact has a manual filling, sealing and loading operation. The VITEK® 2 Systems monitor the growth of each well in the card over a defined period of time. At the completion of the incubation cycle, a report is generated that contains the MIC value along with the interpretive category result for each antibiotic contained on the card.
4
VITEK® 2 AST-GP Lefamulin (≤ 0.03 –>4 µg/mL) has the following concentrations in the card: 0.125, 0.5, 1, and 2 (equivalent standard method concentration by efficacy in ug/mL).
E. Substantial Equivalence Information
The similarities and differences of the VITEK 2 AST-GP Lefamulin (≤ 0.03 – ≥4 µg/mL) when compared to the predicate device, VITEK 2 AST-GP Daptomycin (≤0.12 - ≥8 µg/mL) (K230864), are described in the following table.
| Item | Device:
VITEK® 2 AST-GP Lefamulin | Predicate Device:
VITEK® 2 AST-GP Daptomycin (K230864) |
|--------------------------------------------|---------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------|---------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------|
| Intended Use | General Device Characteristic Similarities
VITEK® 2 AST-GP Lefamulin
( $≤0.03 -≥4 µg/mL$ ) is designed
for antimicrobial susceptibility
testing of Gram-positive
microorganisms and is intended
for use with the VITEK® 2 and
VITEK® 2 Compact Systems as
a laboratory aid in the
determination of in vitro
susceptibility to antimicrobial
agents. VITEK® 2 AST-GP
Lefamulin is a quantitative test.
Lefamulin has been shown to be
active against most strains of the
microorganisms listed below,
according to the FDA label for
this antimicrobial.
The VITEK® 2 Gram-Positive
Susceptibility Card is intended
for use with the VITEK® 2
Systems in clinical laboratories
as an in vitro test to determine
the susceptibility of
Enterococcus spp.,
Staphylococcus spp., and | General Device Characteristic Similarities
VITEK® 2 AST-GP Daptomycin
( $≤0.12 - ≥8 µg/mL$ ) is designed
for antimicrobial susceptibility
testing of Gram-positive
microorganisms and is intended
for use with the VITEK® 2 and
VITEK® 2 Compact Systems as a
laboratory aid in the
determination of in vitro
susceptibility to antimicrobial
agents. VITEK® 2 AST-GP
Daptomycin is a quantitative test.
Daptomycin has been shown to
be active against most strains of
the microorganisms listed below,
according to the FDA label for
this antimicrobial.
The VITEK® 2 Gram-Positive
Susceptibility Card is intended for
use with the VITEK® 2 Systems
in clinical laboratories as an in vitro test to determine the
susceptibility of Enterococcus
spp., Staphylococcus spp., and
Streptococcus agalactiae to |
| Item | Device:
VITEK® 2 AST-GP Lefamulin | Predicate Device:
VITEK® 2 AST-GP
Daptomycin (K230864) |
| General Device Characteristic Similarities | | |
| | Streptococcus agalactiae to
antimicrobial agents when used
as instructed. | antimicrobial agents when used as
instructed. |
| Test Methodology | Automated quantitative
antimicrobial susceptibility test
for use with the VITEK® 2 and
VITEK® 2 Compact Systems to
determine the in vitro
susceptibility of microorganisms | Same |
| Inoculum | Saline suspension of organism | Same |
| Test Card | Gram-positive (AST-GP)
Susceptibility Card | Same |
| Instrument | VITEK® 2 and VITEK® 2
Compact Systems | Same |
| Type of test | Quantitative test | Same |
| Differences | | |
| Antimicrobial Agent | Lefamulin | Daptomycin |
| Concentrations | 0.125, 0.5, 1, 2 | 0.5, 1, 2, 4, 16 |
| Breakpoints | Staphylococcus aureus (MSSA)
(S/I/R) ≤ 0.25 / - / - | Staphylococcus aureus
(S/I/R) ≤ 1 / - / -
Enterococcus faecalis
(S/I/R) ≤ 2 / 4 / ≥ 8 |
| Indicated
Organisms | Active in vitro and in clinical
infections:
Staphylococcus aureus
(methicillin-susceptible isolates) | Active both in vitro and in clinical
infections:
Enterococcus faecalis
(vancomycin- susceptible isolates
only)
Staphylococcus aureus (including
methicillin-resistant isolates)
In vitro data are available. but
their clinical significance is
unknown:
Enterococcus faecalis
(vancomycin- resistant isolates) |
Table 1: Substantial Equivalence
5
6
F. Intended Use:
VITEK® 2 AST-GP Lefamulin is designed for antimicrobial susceptibility testing of Gram-positive microorganisms and is intended for use with the VITEK® 2 and VITEK® 2 COMPACT Systems in clinical laboratories as a laboratory aid in the determination of in vitro susceptibility to antimicrobial agents when used as instructed. VITEK® 2 AST-GP Lefamulin is a quantitative test. Lefamulin has been shown to be active against the microorganisms listed below. according to the FDA label for this antimicrobial.
Active in vitro and in clinical infections: Staphylococcus aureus (methicillin-susceptible isolates)
The VITEK® 2 AST-GP Lefamulin Susceptibility Card is intended for use with the VITEK® 2 Systems in clinical laboratories as an in vitro test to determine the susceptibility of Enterococcus spp., Staphylococcus spp., and Streptococcus agalactiae to antimicrobial agents when used as instructed.
G. Performance Overview and Conclusion:
VITEK® 2 AST-GP Lefamulin demonstrated substantially equivalent performance when compared with the broth microdilution reference method, as defined in the FDA Class II Special Controls Guidance Document: Antimicrobial Susceptibility Test (AST) Systems; Guidance for Industry and FDA (Issued August 28, 2009).
The Premarket Notification (Traditional 510(k)) presents data in support of VITEK® 2 AST-GP Lefamulin. An external evaluation was conducted with fresh and stock clinical isolates, as well as a set of challenge strains. The external evaluations were designed to confirm the acceptability of VITEK® 2 AST-GP Lefamulin by comparing its performance with the CLSI broth microdilution reference method incubated at 16-20 hrs. The data is representative of performance on both the VITEK® 2 and VITEK® 2 Compact instrument platforms.
The VITEK 2 AST-GP Lefamulin demonstrated acceptable performance as presented in Table 2 below:
7
| Antimicrobial | Antimicrobial Code | Antibiotic Version | Bp1 | Comment | Essential Agreement Category | Category Agreement | % Reproducibility | ||||||
|---|---|---|---|---|---|---|---|---|---|---|---|---|---|
| % Error | % Error | ||||||||||||
| %EA | VME | ME | mE | %CA | VME | ME | mE | ||||||
| Lefamulin | LMU | (Imu0 | |||||||||||
| 1n) | CLSI | ||||||||||||
| (FDA) | #, E | ||||||||||||
| Staphylococcus aureus | (367/404) | ||||||||||||
| 90.8 | N/A | N/A | N/A | (403/404) | |||||||||
| 99.8 | (0/3) | ||||||||||||
| 0.0 | (1/401) | ||||||||||||
| 0.2 | N/A | 100.0 | |||||||||||
| VITEK® 2 Lefamulin MIC values tended to be in exact agreement or at least one doubling dilution lower when testing methicillin-susceptible S. aureus compared to the CLSI reference method, broth microdilution. The incubation time (Time of Call) for AST GP cards containing Lefamulin may exceed 16 hours. This extended incubation time is required to generate MIC values. |
Table 2: VITEK 2 AST-GP Lefamulin Performance
1 Abbreviations - Bp = breakpoint committee; EA = essential agreement; CA = category agreement; VME = Very Major Error (susceptible result with resistant reference result); ME = Major Error (resistant result with susceptible reference result); mE = minor Error (susceptible or resistant result with an intermediate reference result, or an intermediate result with a susceptible or resistant reference result).
Kev:
= US Food and Drug Administration 510(k) cleared CLSI® = Clinical and Laboratory Standards Institute E = External performance data
Reproducibility and Quality Control demonstrated acceptable results.
The performance data presented in this submission support a substantial equivalence decision. VITEK® 2 AST-GP Lefamulin (≤0.03 ->2 µg/mL) is substantially equivalent to VITEK® 2 AST-GP Daptomycin (K230864).
References:
-
- MacLowry, J.D. and Marsh, H.H., Semi-automatic Microtechnique for Serial Dilution Antibiotic Sensitivity Testing in the Clinical laboratory, Journal of Laboratory Clinical Medicine, 72:685-687, 1968.
-
- Gerlach, E.H., Microdilution 1: A Comparative Study, p. 63-76. Current Techniques for Antibiotic Susceptibility Testing. A. Balows (ed.), Charles C. Thomas, Springfield, IL, 1974.
8
-
- Barry, A.L., The Antimicrobic Susceptibility Test, Principles and Practices, Lea and Febiger, Philadelphia, PA, 1976.