Clsi Document M45 Pdf [updated] Jun 2026

Always check that your laboratory standard operating procedures (SOPs) match the current active edition of the M45 document.

Includes Corynebacterium diphtheriae and opportunistic pathogens like Corynebacterium striatum .

The is an invaluable resource that bridges a critical gap in antimicrobial susceptibility testing. It empowers clinical, public health, and research laboratories to accurately test and report on a wide array of infrequently isolated and fastidious bacteria that can cause serious infections. By providing standardized methods and interpretative criteria, M45 ensures that even the most unusual pathogens can be tested reliably, leading to more effective treatment decisions and better patient outcomes. As the fight against antimicrobial resistance continues and diagnostic technologies advance, the CLSI M45 guideline remains a dynamic and essential tool for the global laboratory community. clsi document m45 pdf

The document advises which specific drugs should be tested and reported for each organism group. This prevents the unnecessary testing of broad-spectrum antibiotics and promotes antibiotic stewardship. 2. Methodological Guidance

The CLSI M45 standard applies to veterinary clinical laboratories that perform antimicrobial susceptibility testing on bacteria isolated from animals. The standard covers the testing of aerobic and anaerobic bacteria, including those that are commonly isolated from animals. The document advises which specific drugs should be

Unlike M100, M45 does not always provide “S/I/R” (Susceptible/Intermediate/Resistant) breakpoints for every drug-organism pair due to limited clinical data. Instead, you may find:

The 2016 third edition was a substantial update. It introduced and included several new tables to address organisms that were becoming more easily identifiable by advanced methods like sequencing or matrix-assisted laser desorption/ionization time-of-flight mass spectrometry (MALDI-TOF MS). The intent was to help laboratories determine an approach for testing these diverse organisms that is relevant to their specific practice settings and available technologies. Notably, the third edition is available as an electronic PDF only , comprising 120 pages. consider the following operational tips:

Specific for a particular organism mentioned in M45.

Many hospital libraries or university networks maintain corporate subscriptions to the CLSI eCLIPSE platform, granting staff legal access to the PDF.

To successfully integrate the CLSI M45 guidance into your routine workflow, consider the following operational tips: