Test Catalog

Test Id : MMLSA

Antimicrobial Susceptibility, Anaerobic Bacteria, Minimal Inhibitory Concentration, Varies

Useful For
Suggests clinical disorders or settings where the test may be helpful

Determining the in vitro susceptibility on isolates of anaerobic bacteria involved in human infections

 

Directing antimicrobial therapy for anaerobic bacterial infections

Reflex Tests
Lists tests that may or may not be performed, at an additional charge, depending on the result and interpretation of the initial tests.

Test Id Reporting Name Available Separately Always Performed
COMM Identification Commercial Kit No, (Bill Only) No
RMALD Ident by MALDI-TOF mass spec No, (Bill Only) No
GID Bacteria Identification No, (Bill Only) No
ISAE Aerobe Ident by Sequencing No, (Bill Only) No
REFID Additional Identification Procedure No, (Bill Only) No
SALS Serologic Agglut Method 1 Ident No, (Bill Only) No
EC Serologic Agglut Method 2 Ident No, (Bill Only) No
SHIG Serologic Agglut Method 3 Ident No, (Bill Only) No
STAP Identification Staphylococcus No, (Bill Only) No
STRP Identification Streptococcus No, (Bill Only) No
SIDC Ident Serologic Agglut Method 4 No, (Bill Only) No
ANAID Anaerobe Ident No, (Bill Only) No
RMALA Id MALDI-TOF Mass Spec Anaerobe No, (Bill Only) No
ISAN Anaerobe Ident by Sequencing No, (Bill Only) No
PCRID Identification by PCR No, (Bill Only) No
BLA Beta Lactamase No, (Bill Only) No
SANA Anaerobe Suscep per agent No, (Bill Only) No
ANIDE Organism Ref for ID, Anaerobic Bact Yes No

Additional Tests
Lists tests that are always performed, at an additional charge, with the initial tests.

Test Id Reporting Name Available Separately Always Performed
BATTA Anaerobe Suscep Battery No Yes

Testing Algorithm
Delineates situations when tests are added to the initial order. This includes reflex and additional tests.

When this test is ordered, the reflex tests may be performed at an additional charge. All anaerobic bacterial organisms recovered will automatically have susceptibility testing performed and billed as appropriate. Antimicrobial agents appropriate to the organism and specimen source will be tested according to Mayo Clinic's practice and the laboratory's standard operating procedures.

 

For a listing of the antimicrobials routinely tested in this laboratory as well as antimicrobials that may be tested upon request, see Anaerobic Bacteria Antimicrobials. If the organism or antimicrobial agent of interest is not listed in this table, call 800-533-1710 and ask to speak to the Bacteriology Anaerobe Laboratory.

 

If organism identification is not provided within 72 hours of specimen receipt, referred anaerobic bacteria identification will be performed at an additional charge.

Method Name
A short description of the method used to perform the test

Minimal Inhibitory Concentration (MIC) by Agar Dilution

NY State Available
Indicates the status of NY State approval and if the test is orderable for NY State clients.

Yes

Reporting Name
Lists a shorter or abbreviated version of the Published Name for a test

Susceptibility, Anaerobic, MIC

Aliases
Lists additional common names for a test, as an aid in searching

Antibiotic Susceptibility

Bacterial Susceptibility Testing (1 test)

MIC Test, Anaerobic Bacteria

Susceptibility Testing

Minimum Inhibitory Concentration (MIC)

Clindamycin

Ertapenem

Metronidazole

Minocycline

Moxifloxacin

Penicillin

Piperacillin-tazobactam

Amoxicillin-clavulanate

Cefotaxime

Ceftriaxone

Ciprofloxacin

Meropenem

Vancomycin

Actinobaculum

Actinomyces

Anaerococcus

Bacteroides

Bifidobacterium

Campylobacter

Clostridium

Clostridioides

Cutibacterium

Eggerthella

Finegoldia

Fusobacterium

Peptoniphilus

Porphyromonas

Prevotella

Propionibacterium

Staphylococcus saccharolyticus

Veillonella

Helcococcus

Lactobacillus

Ampicillin-sulbactam

Imipenem

Minimal Inhibitory Concentration (MIC)

Rifampin

Testing Algorithm
Delineates situations when tests are added to the initial order. This includes reflex and additional tests.

When this test is ordered, the reflex tests may be performed at an additional charge. All anaerobic bacterial organisms recovered will automatically have susceptibility testing performed and billed as appropriate. Antimicrobial agents appropriate to the organism and specimen source will be tested according to Mayo Clinic's practice and the laboratory's standard operating procedures.

 

For a listing of the antimicrobials routinely tested in this laboratory as well as antimicrobials that may be tested upon request, see Anaerobic Bacteria Antimicrobials. If the organism or antimicrobial agent of interest is not listed in this table, call 800-533-1710 and ask to speak to the Bacteriology Anaerobe Laboratory.

 

If organism identification is not provided within 72 hours of specimen receipt, referred anaerobic bacteria identification will be performed at an additional charge.

Specimen Type
Describes the specimen type validated for testing

Varies

Shipping Instructions

For shipping information, see Infectious Specimen Shipping Guidelines.

Necessary Information

Organism identification and specimen source are required.

ORDER QUESTIONS AND ANSWERS

Question ID Description Answers
Q00M0039 Specimen Source (Required) and Organism Identification (Required unless concurrent identification test is ordered)

Specimen Required
Defines the optimal specimen required to perform the test and the preferred volume to complete testing

Supplies:

Anaerobic Transport Tube (T588)

Infectious Container, Large (T146)

Acceptable Sources: Isolates from blood cultures, bone and joint infections, or brain abscesses, and organisms isolated in pure culture from other sources

Container/Tube:

Preferred: Anaerobic transport tube

Acceptable: Thioglycollate broth or any other suitable anaerobic transport system

Collection Instructions :

1. Organism must be in pure culture and actively growing. Do not submit mixed cultures.

2. Place specimen in a large infectious container and label as an etiologic agent/infectious substance if appropriate

Special Instructions
Library of PDFs including pertinent information and forms related to the test

Forms

If not ordering electronically, complete, print, and send a Microbiology Test Request (T244) with the specimen.

Reject Due To
Identifies specimen types and conditions that may cause the specimen to be rejected

Agar plate Reject

Specimen Stability Information
Provides a description of the temperatures required to transport a specimen to the performing laboratory, alternate acceptable temperatures are also included

Specimen Type Temperature Time Special Container
Varies Ambient

Useful For
Suggests clinical disorders or settings where the test may be helpful

Determining the in vitro susceptibility on isolates of anaerobic bacteria involved in human infections

 

Directing antimicrobial therapy for anaerobic bacterial infections

Testing Algorithm
Delineates situations when tests are added to the initial order. This includes reflex and additional tests.

When this test is ordered, the reflex tests may be performed at an additional charge. All anaerobic bacterial organisms recovered will automatically have susceptibility testing performed and billed as appropriate. Antimicrobial agents appropriate to the organism and specimen source will be tested according to Mayo Clinic's practice and the laboratory's standard operating procedures.

 

For a listing of the antimicrobials routinely tested in this laboratory as well as antimicrobials that may be tested upon request, see Anaerobic Bacteria Antimicrobials. If the organism or antimicrobial agent of interest is not listed in this table, call 800-533-1710 and ask to speak to the Bacteriology Anaerobe Laboratory.

 

If organism identification is not provided within 72 hours of specimen receipt, referred anaerobic bacteria identification will be performed at an additional charge.

Clinical Information
Discusses physiology, pathophysiology, and general clinical aspects, as they relate to a laboratory test

Anaerobic bacteria are the greatest component of the human body's normal bacterial flora. Anaerobic bacteria colonize the skin, oral cavity, and genitourinary and lower gastrointestinal tracts and generally do not cause infection. Their presence is important for vitamin and other nutrient absorption and in preventing infection with disease-causing bacteria.

 

When usual skin and mucosal barriers are compromised, in an anaerobic environment, these bacteria can behave as pathogens. Typical anaerobic infections include periodontitis, abdominal or pelvic abscesses, endometritis, pelvic inflammatory disease, aspiration pneumonia, empyema and lung abscesses, sinusitis, brain abscesses, gas gangrene, and other soft tissue infections.

 

Anaerobic bacteria grow aggressively in the body under anaerobic conditions and may possess a variety of virulence factors, including capsules and extracellular enzymes. They also can develop resistance to antimicrobials by producing beta-lactamase and other modifying enzymes, and by alterations in membrane permeability and structure of penicillin-binding proteins. Susceptibility testing results are useful to clinicians because anaerobic bacteria are a significant cause of human infection, and they are often resistant to commonly used antimicrobials. Bacteroides and Parabacteroides species produce beta-lactamases. Ertapenem, metronidazole, and clindamycin are generally effective agents, although resistance to clindamycin, and occasionally ertapenem, is increasing.

 

The minimal inhibitory concentration (MIC) obtained during antimicrobial susceptibility testing is helpful in indicating the concentration of antimicrobial agent required at the site of infection necessary to inhibit the infecting organism. For each organism-antimicrobial agent combination, the Clinical and Laboratory Standards Institute and/or the European Committee on Antimicrobial Susceptibility Testing provides interpretive criteria for determining whether the MIC should be interpreted as susceptible, susceptible dose dependent, intermediate, nonsusceptible, resistant, or epidemiological cutoff value.

Reference Values
Describes reference intervals and additional information for interpretation of test results. May include intervals based on age and sex when appropriate. Intervals are Mayo-derived, unless otherwise designated. If an interpretive report is provided, the reference value field will state this.

Susceptibility results are reported as minimal inhibitory concentration (MIC) in mcg/mL Breakpoints (also known as "clinical breakpoints") are used to categorize an organism as susceptible, susceptible-dose dependent, intermediate, resistant or nonsusceptible according to breakpoint setting organizations, either the Clinical and Laboratory Standards Institute (CLSI) or the European Committee on Antimicrobial Susceptibility Testing (EUCAST), as applicable.

 

In some instances, an interpretive category cannot be provided based on available data and the following comment will be included: "There are no established interpretive guidelines for agents reported without interpretations."

 

CLSI Interpretive Category Definitions:

Susceptible:

A category defined by a breakpoint that implies that isolates with an MIC at or below or a zone diameter at or above the susceptible breakpoint are inhibited by the usually achievable concentrations of antimicrobial agent when the dosage recommended to treat the site of infection is used, resulting in likely clinical efficacy.

 

Susceptible-Dose Dependent:

A category defined by a breakpoint that implies that susceptibility of an isolate depends on the dosing regimen that is used in the patient. To achieve levels that are likely to be clinically effective against isolates for which the susceptibility testing results (either MICs or zone diameters) are in the susceptible-dose dependent (SDD) category, it is necessary to use a dosing regimen (ie, higher doses, more frequent doses, or both) that results in higher drug exposure than that achieved with the dose that was used to establish the susceptible breakpoint. Consideration should be given to the maximum literature-supported dosage regimens because higher exposure gives the highest probability of adequate coverage of a SDD isolate. The drug label should be consulted for recommended doses and adjustment for organ function.

 

Intermediate:

A category defined by a breakpoint that includes isolates with MICs or zone diameters within the intermediate range that approach usually attainable blood and tissue levels and/or for which response rates may be lower than for susceptible isolates.

Note: The intermediate category implies clinical efficacy in body sites where the drugs are physiologically concentrated or when a higher-than-normal dosage of a drug can be used. This category also includes a buffer zone, which should prevent small, uncontrolled, technical factors from causing major discrepancies in interpretations, especially for drugs with narrow pharmacotoxicity margins.

 

Resistant:

A category defined by a breakpoint that implies that isolates with an MIC at or above or a zone diameter at or below the resistant breakpoint are not inhibited by the usually achievable concentrations of the agent with normal dosage schedules and/or that demonstrate MICs or zone diameters that fall in the range in which specific microbial resistance mechanisms are likely, and clinical efficacy of the agent against the isolate has not been reliably shown in treatment studies.

 

Nonsusceptible:

A category used for isolates for which only a susceptible breakpoint is designated because of the absence or rare occurrence of resistant strains. Isolates for which the antimicrobial agent MICs are above or the zone diameters are below the value indicated for the susceptible breakpoint should be reported as nonsusceptible.

Note: An isolate that is interpreted as nonsusceptible does not necessarily mean that the isolate has a resistance mechanism. It is possible that isolates with MICs above the susceptible breakpoint that lack resistance mechanisms may be encountered within the wild-type distribution after the time the susceptible-only breakpoint was set.

 

Epidemiological Cutoff Value:

The MIC that separates microbial populations into those with and without phenotypically detectable resistance (non-wildtype or wildtype, respectively). The epidemiological cutoff value (ECV) defines the highest MIC for the wildtype population of isolates. ECVs are based on in vitro data only, using MIC distributions. ECVs are not clinical breakpoints, and the clinical relevance of ECVs for a particular patient has not yet been identified or approved by CLSI or any regulatory agency.

 

When an ECV is reported, an interpretive category is not assigned, and the following comment will be included:

This MIC is consistent with the Epidemiological Cutoff Value (ECV) observed in isolates (WITH / WITHOUT) acquired resistance; however, correlation with treatment outcome is unknown.

 

Wildtype (WT): An interpretive category defined by an ECV that describes the microbial population with no phenotypically detectable mechanisms of resistance or reduced susceptibility for an antimicrobial agent being evaluated.

 

Non-wildtype (NWT): An interpretive category defined by an ECV that describes the microbial population with phenotypically detectable mechanisms of resistance or reduced susceptibility for the antimicrobial agent being evaluated.

Note: MIC values for which ECVs are defined are not to be interpreted or reported as susceptible, intermediate, or resistant but rather as WT or NWT. The ECVs should not be used as clinical breakpoints.(Clinical and Laboratory Standards Institute [CLSI]. Performance Standards for Antimicrobial Susceptibility Testing. 33rd ed. CLSI supplement M100. CLSI; 2023:8-10, 312-314)

 

European Committee on Antimicrobial Susceptibility Testing (EUCAST) Interpretive Category Definitions:

S - Susceptible, standard dosing regimen: A microorganism is categorized as "Susceptible, standard dosing regimen", when there is a high likelihood of therapeutic success using a standard dosing regimen of the agent

 

I - Susceptible, increased exposure*: A microorganism is categorized as "Susceptible, Increased exposure*" when there is a high likelihood of therapeutic success because exposure to the agent is increased by adjusting the dosing regimen or by its concentration at the site of infection.

 

R - Resistant: A microorganism is categorized as "Resistant" when there is a high likelihood of therapeutic failure even when there is increased exposure*.

 

*Exposure is a function of how the mode of administration, dose, dosing interval, infusion time, as well as distribution and excretion of the antimicrobial agent will influence the infecting organism at the site of infection.

 

(The European Committee on Antimicrobial Susceptibility Testing. Breakpoint tables for interpretation of MICs and zone diameters. V11.0, 2021. Available at www.eucast.org.)

Interpretation
Provides information to assist in interpretation of the test results

A "susceptible" category result and a low minimal inhibitory concentration value indicates in vitro susceptibility of the organism to the antimicrobial tested.

 

For interpretation of various antimicrobial susceptibility interpretive categories (ie, susceptible, intermediate, resistant, or epidemiological cutoff value), see Reference Values.

Cautions
Discusses conditions that may cause diagnostic confusion, including improper specimen collection and handling, inappropriate test selection, and interfering substances

In vitro susceptibility does not guarantee clinical response. Therefore, the decision to treat with a particular agent should not be based solely on the antimicrobial susceptibility testing result.

Clinical Reference
Recommendations for in-depth reading of a clinical nature

1. Rosenblatt JE, Brook I. Clinical relevance of susceptibility testing of anaerobic bacteria. Clin Infect Dis. 1993;16(Suppl 4):S446-S448

2. Jenkins SG, Schuetz AN. Current concepts in laboratory testing to guide antimicrobial therapy. Mayo Clin Proc. 2012;87(3):290-308

3. Schuetz AN, Carpenter DE. Susceptibility test methods: anaerobic bacteria. In: Carroll KC, Pfaller MA, eds. Manual of Clinical Microbiology. 12th ed. ASM Press; 2019:1377-1397

4. Jenkins SG, Schuetz AN. Current concepts in laboratory testing to guide antimicrobial therapy. Mayo Clin Proc. 2012;87(3):290-308

Method Description
Describes how the test is performed and provides a method-specific reference

An agar dilution method is used for routine testing. The antimicrobial is added to agar in various concentrations depending upon levels attainable in serum. A standardized suspension of the organism is applied to the agar plates, which are incubated anaerobically for 42 to 48 hours at 35 to 37 degrees C. The end point is that in which a marked reduction occurs in the appearance of growth on the test plate as compared to that of growth on the control plate. Examples of marked change include a change from confluent growth to a haze, less than 10 tiny colonies, or 1 to 3 normal-sized colonies.(Clinical and Laboratory Standards Institute [CLSI]: Methods for Antimicrobial Susceptibility Testing of Anaerobic Bacteria. 9th ed. CLSI standard M11. CLSI; 2018)

PDF Report
Indicates whether the report includes an additional document with charts, images or other enriched information

No

Day(s) Performed
Outlines the days the test is performed. This field reflects the day that the sample must be in the testing laboratory to begin the testing process and includes any specimen preparation and processing time before the test is performed. Some tests are listed as continuously performed, which means that assays are performed multiple times during the day.

Monday through Sunday

Report Available
The interval of time (receipt of sample at Mayo Clinic Laboratories to results available) taking into account standard setup days and weekends. The first day is the time that it typically takes for a result to be available. The last day is the time it might take, accounting for any necessary repeated testing.

8 to 14 days

Specimen Retention Time
Outlines the length of time after testing that a specimen is kept in the laboratory before it is discarded

30 days

Performing Laboratory Location
Indicates the location of the laboratory that performs the test

Rochester

Fees
Several factors determine the fee charged to perform a test. Contact your U.S. or International Regional Manager for information about establishing a fee schedule or to learn more about resources to optimize test selection.

  • Authorized users can sign in to Test Prices for detailed fee information.
  • Clients without access to Test Prices can contact Customer Service 24 hours a day, seven days a week.
  • Prospective clients should contact their account representative. For assistance, contact Customer Service.

Test Classification
Provides information regarding the medical device classification for laboratory test kits and reagents. Tests may be classified as cleared or approved by the US Food and Drug Administration (FDA) and used per manufacturer instructions, or as products that do not undergo full FDA review and approval, and are then labeled as an Analyte Specific Reagent (ASR) product.

This test has been cleared, approved, or is exempt by the US Food and Drug Administration and is used per manufacturer's instructions. Performance characteristics were verified by Mayo Clinic in a manner consistent with CLIA requirements.

CPT Code Information
Provides guidance in determining the appropriate Current Procedural Terminology (CPT) code(s) information for each test or profile. The listed CPT codes reflect Mayo Clinic Laboratories interpretation of CPT coding requirements. It is the responsibility of each laboratory to determine correct CPT codes to use for billing.

CPT codes are provided by the performing laboratory.

87186-Antimicrobial Susceptibility, Anaerobic Bacteria, MIC

87076-Organism Ref for ID, Anaerobic Bact (if appropriate)

87076-Anaerobe Ident (if appropriate)

87076-Id MALDI-TOF Mass Spec Anaerobe (if appropriate)

87153-Anaerobe ident by sequencing (if appropriate)

87150-Identification by PCR (if appropriate)

87185-Beta Lactamase (if appropriate)

87181-Anaerobe Susceptibility per Agent (if appropriate)

LOINC® Information
Provides guidance in determining the Logical Observation Identifiers Names and Codes (LOINC) values for the order and results codes of this test. LOINC values are provided by the performing laboratory.

Test Id Test Order Name Order LOINC Value
MMLSA Susceptibility, Anaerobic, MIC 50545-3
Result Id Test Result Name Result LOINC Value
Applies only to results expressed in units of measure originally reported by the performing laboratory. These values do not apply to results that are converted to other units of measure.
MMLSA Susceptibility, Anaerobic, MIC 50545-3

Test Setup Resources

Setup Files
Test setup information contains test file definition details to support order and result interfacing between Mayo Clinic Laboratories and your Laboratory Information System.

Excel | PHP Pdf | CMS Pdf

Sample Reports
Normal and Abnormal sample reports are provided as references for report appearance.

Normal Reports | Abnormal Reports

SI Sample Reports
International System (SI) of Unit reports are provided for a limited number of tests. These reports are intended for international account use and are only available through MayoLINK accounts that have been defined to receive them.

SI Normal Reports | SI Abnormal Reports