Notice of Updates

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For information regarding prior changes to the STIC webpages, see https://www.govinfo.gov/content/pkg/FR-2019-05-03/pdf/2019-09007.pdf

https://www.federalregister.gov/documents/2020/10/22/2020-23439/21st-century-cures-act-annual-compilation-of-notices-of-updates-from-the-susceptibility-test

https://www.federalregister.gov/documents/2023/05/18/2023-10603/21st-century-cures-act-annual-compilation-of-notices-of-updates-from-the-susceptibility-test

https://www.federalregister.gov/documents/2024/04/09/2024-07495/21st-century-cures-act-annual-compilation-of-notices-of-updates-from-the-susceptibility-test

Updates to Standards Recognition

As of January 16, 2025, unless specific exceptions and additions are identified, FDA fully recognizes the standards published in:
Clinical and Laboratory Standards Institute (CLSI). Performance Standards for Antimicrobial Susceptibility Testing. 34^th ed. CLSI supplement M100; 2024.
Clinical and Laboratory Standards Institute (CLSI). Methods for Antimicrobial Dilution and Disk Susceptibility Testing of Infrequently Isolated or Fastidious Bacteria. 3rd ed. CLSI document M45; 2015. 
Clinical and Laboratory Standards Institute (CLSI). Performance Standards for Susceptibility Testing of Mycobacteria, Nocardia spp., and Other Aerobic Actinomycetes, 2nd Ed. CLSI document M24S; 2023.
Clinical and Laboratory Standards Institute (CLSI). Methods for Antimicrobial Susceptibility Testing for Human Mycoplasmas; Approved Guideline. 1^st ed. CLSI document M43-A; 2011.
Clinical and Laboratory Standards Institute (CLSI). Performance Standards for Antifungal Susceptibility Testing of Filamentous Fungi. 3rd Ed. CLSI document M38M51S; 2022.

Updates by Drug:

Drug	Route of Administration	Action Taken	Therapeutic Category	Date
Amikacin	Injection	FDA does not recognize M100 standard (MIC and disk diffusion) for Enterobacterales and Pseudomonas aeruginosa	Antibacterial	4/21/2023
Amoxicillin and clavulanate	Oral	FDA does not recognize M100 standard and provides STIC for Haemophilus influenzae.	Antibacterial	5/17/2022
Azithromycin	Oral, Injection	FDA identified STIC (MIC) for Neisseria gonorrhoeae. Rationale	Antibacterial	1/16/2025
Azithromycin	Oral, Injection	For Neisseria gonorrhoeae, FDA has reviewed STIC and concludes no changes are needed at this time. Rationale	Antibacterial	10/14/2021
Cefadroxil	Oral	FDA removed the statement “Susceptibility of Enterobacteriaceae to cefadroxil may be deduced from testing cefazolin.” Rationale	Antibacterial	4/27/2022
Cefazolin	Injection	FDA does not recognize M100 standard for cefazolin as a surrogate to predict susceptibility of oral cephalosporins when used for the treatment of uncomplicated UTI caused by Escherichia coli, Klebsiella pneumoniae and Proteus mirabilis. Rationale	Antibacterial	10/20/2022
Cefazolin	Injection	For Enterobacterales, FDA has reviewed STIC and the updated standard is recognized. Rationale	Antibacterial	10/14/2021
Cefepime	Injection	FDA recognizes M100 standard (MIC and disk diffusion) for P. aeruginosa	Antibacterial	1/16/2025
Cefepime	Injection	FDA recognizes M100 susceptible-dose dependent standard (MIC and disk diffusion) for Enterobacterales	Antibacterial	6/21/2023
Cefepime and Enmetazobactam	Injection	FDA identified STIC (MIC and disk diffusion) for Enterobacterales and P. aeruginosa.	Antibacterial	2/22/2024
Cefiderocol	Injection	FDA recognizes M100 MIC standard and identifies disk diffusion STIC for S. maltophilia. Rationale	Antibacterial	11/12/2024
Cefiderocol	Injection	FDA recognizes M100 (disk diffusion) standards for Enterobacterales.	Antibacterial	1/31/2023
Cefiderocol	Injection	FDA recognizes M100 MIC standard for Enterobacteriaceae.	Antibacterial	10/14/2021
Cefiderocol	Injection	FDA has updated STIC and added STIC for Acinetobacter baumannii complex.	Antibacterial	9/25/2020
Cefoxitin	Injection	FDA recognizes M100 standard for Staphylococcus aureus complex and Staphylococcus lugdunensis; FDA recognizes M100 disk diffusion standard for Staphylococcus epidermidis and other Staphylococci spp.	Antibacterial	10/04/2022
Ceftaroline fosamil	Injection	FDA recognizes the M100 standard (MIC and disk diffusion) for Staphylococcus aureus. Rationale	Antibacterial	6/25/2024
Ceftaroline fosamil	Injection	For Staphylococcus aureus, FDA has reviewed the STIC and concludes no changes are needed at this time. Rationale	Antibacterial	4/16/2020
Ceftazidime	Injection	FDA recognizes M100 standard (MIC and disk diffusion) for P. aeruginosa	Antibacterial	1/16/2025
Ceftazidime	Injection	FDA concurs with CLSI to remove STIC (MIC) for S. maltophilia. Rationale	Antibacterial	5/15/2024
Ceftobiprole medocaril sodium	Injection	FDA identified STIC for S. aureus, S. pyogenes, and Enterobacterales (MIC and disk diffusion), and for S. pneumoniae, H. influenzae and H. parainfluenzae (MIC).	Antibacterial	4/03/2024
Ceftolozane Tazobactam	Injection	FDA recognizes M100 standard for Haemophilus influenzae.	Antibacterial	10/14/2021
Ceftolozane and tazobactam	Injection	FDA recognizes M100 disk diffusion standard for Enterobacterales.	Antibacterial	5/17/2022
Ciprofloxacin	Oral, Injection	For Salmonella spp., the updated standard is recognized.	Antibacterial	2/28/2020
Chloramphenicol	Injection	FDA does not recognize M45 standard for Abiotrophia spp., Granulicatella spp., and Aeromonas spp.	Antibacterial	1/16/2025
Clindamycin	Injection, Oral	FDA does not recognize M45 standard for Moraxella catarrhalis	Antibacterial	1/16/2025
Colistimethate	Injection	FDA does not recognize M100 standard (MIC) for Enterobacterales, Pseudomonas aeruginosa, or Acinetobacter spp. Rationale	Antibacterial	1/17/2023
Daptomycin	Injection	FDA recognizes M100 standard (MIC) for E. faecium and Enterococcus spp. other than E. faecium. Rationale	Antibacterial	8/2/2024
Daptomycin	Injection	FDA updated STIC. Rationale	Antibacterial	8/25/2020
Delafloxacin	Injection, Oral	FDA identified STIC for Staphylococcus lugdunensis for Acute Bacterial Skin and Skin Structure Infections.	Antibacterial	10/06/2020
Fluconazole	Injection, Oral	FDA recognizes M27M44S susceptible-dose dependent standard (MIC and disk diffusion) for Candida species.	Antifungal	8/10/2023
Gentamicin	Injection	FDA does not recognize M100 standard (MIC and disk diffusion) for Enterobacterales and Pseudomonas aeruginosa	Antibacterial	4/21/2023
Imipenem-Cilastatin-Relebactam	Injection	FDA recognizes M100 standard for Enterobacteriaceae, Pseudomonas aeruginosa, and anaerobes.	Antibacterial	10/14/2021
Imipenem-Cilastatin-Relebactam	Injection	FDA identified STIC for Acinetobacter calcoaceticus-baumannii complex and Haemophilus influenzae.	Antibacterial	6/4/2020
Lefamulin	Oral, Injection	FDA recognizes M100 standard (MIC and disk diffusion) for Staphylococcus aureus (methicillin-susceptible isolates), Streptococcus pneumoniae, and Haemophilus influenzae.	Antibacterial	2/16/2023
Lefamulin	Oral, Injection	FDA does not recognize M100 disk diffusion standard and provides STIC for Streptococcus pneumoniae and Haemophilus influenzae.	Antibacterial	5/17/2022
Lefamulin	Oral, Injection	FDA recognizes M100 standard for Staphylococcus aureus, Streptococcus pneumoniae, and Haemophilus influenzae.	Antibacterial	10/14/2021
Levofloxacin	Oral, Injection	For Salmonella spp., the updated standard is recognized.	Antibacterial	2/28/2020
Linezolid	Oral, Injection	FDA recognizes M100 (disk diffusion) standard for S. aureus.	Antibacterial	5/28/2024
Ofloxacin	Oral	For Salmonella spp., the updated standard is recognized.	Antibacterial	2/28/2020
Omadacycline	Injection, Oral	FDA updated disk breakpoints for Streptococcus pneumoniae for community acquired bacterial pneumonia.	Antibacterial	8/25/2020
Oxacillin	Injection	FDA concurs with the revised CLSI STIC for Staphylococcus by species level. Rationale; FDA references Cefoxitin STIC for Staphylococcus spp. as a surrogate test.	Antibacterial	10/04/2022
Piperacillin and Tazobactam	Injection	FDA recognizes M100 standard (MIC and disk diffusion) for P. aeruginosa. Rationale	Antibacterial	1/16/2025
Piperacillin and Tazobactam	Injection	FDA has updated STIC (MIC and disk diffusion) for P. aeruginosa. FDA identified a susceptible-dose dependent breakpoint. FDA does not recognize M100 standard for a susceptible, intermediate, and resistance breakpoints. Rationale	Antibacterial	3/22/2024
Piperacillin and Tazobactam	Injection	FDA has updated STIC (MIC and disk diffusion) for Enterobacterales. FDA has recognized M100 standard for susceptible and resistant breakpoints and updated an intermediate breakpoint. FDA does not recognize M100 standard for a susceptible dose dependent breakpoint. Rationale	Antibacterial	1/17/2023
Pivmecillinam	Oral	FDA recognizes M100 standard (MIC and disk diffusion) for Enterobacterales	Antibacterial	4/24/2024
Plazomicin	Injection	FDA recognizes M100 standard (MIC and disk diffusion) for Enterobacterales	Antibacterial	4/21/2023
Polymyxin B	Injection	FDA does not recognize M100 standard (MIC) for Enterobacterales, Pseudomonas aeruginosa, or Acinetobacter spp. Rationale	Antibacterial	1/17/2023
Rezafungin	Injection	FDA identified STIC (MIC and disk diffusion) for C. albicans, C. glabrata, and C. tropicalis. FDA has reviewed STIC (MIC) for C. parapsilosis, and the M27M44S standard is recognized. FDA identified STIC (disk diffusion) for C. parapsilosis.	Antifungal	4/18/2023
Rifampin	Oral, Injection	FDA does not recognize M45 standard for HACEK group: Haemophilus spp., Aggregatibacter spp., Cardiobacterium hominis, Eikenella corrodens and Kingella spp., and for Moraxella catarrhalis	Antibacterial	1/16/2025
Sulbactam and Durlobactam	Injection	FDA recognizes M100 standard (MIC and disk diffusion) for Acinetobacter baumannii-calcoaceticus complex.	Antibacterial	6/06/2023
Sulopenem etzadroxil and probenecid	Oral	FDA identified STIC (MIC and disk diffusion) for Enterobacterales.	Antibacterial	10/25/2024
Tedizolid phosphate	Oral, injection	FDA recognizes M100 (disk diffusion) standard for S. aureus, Streptococcus spp. beta-hemolytic group, and Streptococcus spp. viridans group.	Antibacterial	5/28/2024
Telithromycin	Oral	FDA has removed telithromycin STIC as the drug is no longer approved in any application under section 505 of the FD&C Act (see 84 FR 47309).	Antibacterial	10/14/2021
Tobramycin	Injection	FDA does not recognize M100 standard (MIC and disk diffusion) for Enterobacterales and Pseudomonas aeruginosa	Antibacterial	4/21/2023
Voriconazole	Tablets, Powder for Oral Suspension, Injection	FDA recognizes M38M51S standard for Aspergillus fumigatus. Rationale	Antifungal	1/16/2025

* M100 standard in the table refers to CLSI Performance Standards for Antimicrobial Susceptibility Testing, 34^th ed. CLSI supplement M100; 2024.