Advanced Antibacterial & Antifungal Discovery

Antibacterial and Antifungal Screening and MIC Susceptibility Testing

We work with your team to design screening strategies that mirror real-world clinical challenges. By leveraging our repository of resistant clinical isolates and CLSI-standardized methods, we provide data you can trust to advance promising compounds with confidence. Our collaborative approach ensures studies are tailored to your program needs, helping reduce risk in later development phases.

Integrated High-Throughput Screening, MIC Analysis, and Susceptibility Testing

Microbiologics provides high-throughput screening, Minimum Inhibitory Concentration (MIC) testing, and test method development supported by a large repository of clinical isolates. Our services span early compound screening through detailed lead optimization and characterization. By combining advanced technology with real-world clinical isolates, we help developers identify and prioritize the most promising compounds faster, reducing risk during later stages of drug development.

Repository of Clinical Isolates

Our expansive repository includes recent clinical isolates of key Gram-positive and Gram-negative pathogens, anaerobes, and fungi, along with nontuberculous mycobacteria (NTM) and reference strains of Mycobacterium tuberculosis. Additionally, we maintain 2,500 sequenced ESKAPE isolates with genetically characterized resistance mechanisms such as KPC, NDM-1, and OXA, ensuring compound testing reflects clinically relevant challenges.

High-Throughput Screening

Using Biomek 3000 and Biomek FX platforms, we conduct whole-cell antimicrobial screening across bacteria, yeasts, and fungi. Compound collections are able to be screened in either 96 or 384 well format. Endpoints include:

• MIC values (visual reads)
• Optical density measurements
• Luminescence outputs (BioTek, BacTiter-Glo)

This enables rapid, scalable screening to prioritize promising leads and accelerate your development pipeline.

Primary and Secondary Profiling

To define spectrum of activity and guide decision-making, we offer:

Primary profiling: Susceptibility testing of lead compounds against clinically relevant Gram-positive and Gram-negative organisms, with the option to include anaerobes and fungi.

Secondary profiling: Expanded MIC studies against representative pathogen populations to determine MIC50 and MIC90 values, helping differentiate and rank candidate compounds.

Susceptibility Testing Methodologies

All susceptibility testing is performed under CLSI standards (M2, M7, M11, M24, M27, M38, M100) to ensure rigor and reproducibility.

Broth Microdilution (MIC Testing): Custom 96-well panels; compounds accepted as dry powders or solutions.

Agar Dilution (MIC Testing): Standardized MIC evaluation in agar formats.

Disk Diffusion Testing: Using either manufactured disks or Microbiologics in-house prepared disks.

Lead Characterization and Antimicrobial Development Studies

Our scientists partner with you to uncover the mechanism of action, evaluate pharmacodynamics, and assess resistance development. By integrating molecular, biochemical, and whole-cell approaches, we generate decision-ready data that supports IND submissions and informs trial design. This customized support accelerates your discovery efforts while strengthening regulatory confidence.

Mechanism of Action Studies (MOA)

Determining the mechanism of action (MOA) of new agents is essential to the discovery process and a required component of the Investigational New Drug (IND) filing. Microbiologics utilizes whole cell, molecular, and biochemical techniques to determine MOA. We provide macromolecular synthesis inhibition, transcription and translation assays (cell-free), cell-lysis assays (ATP leakage, RBC lysis), and enzyme assays (IC₅₀ studies). With this comprehensive approach, we deliver actionable insights that strengthen regulatory submissions and inform clinical strategy.

In Vitro Pharmacodynamic Studies ("TK" to PAE, SME, PA-SME)

Following CLSI protocols (such as CLSI M26) where applicable, Microbiologics conducts an assessment of an antimicrobial agent’s ability to kill or suppress growth of target organisms using assays including time-kill, minimum bactericidal or fungicidal concentration (MBC/MFC), serum bactericidal titer, and post-antibiotic effect. These studies provide critical data to guide dosing strategies and support your IND application.

Development of Resistance Studies

An assessment of the ability of bacteria to develop resistance to new agents is an important early consideration in the discovery phase. Microbiologics provides spontaneous mutation frequency (SMF) or frequency of resistance (FoR) assays and serial passage assays to address this need. By identifying potential resistance pathways early, we help sponsors reduce downstream clinical trial risks.

Custom Test Method Development

Tier 1 Quality Control and Parameter Studies (CLSI M23): Evaluation of testing parameters on in vitro activity (e.g. pH, inoculum size, cation concentration, protein binding and serum activity).

Development of preliminary Tier 1 Quality Control Ranges at a single test laboratory in accordance with CLSI M23.

Tier 2 Broth/Agar MIC and Disk CLSI M23 Quality Control Studies: Multi-laboratory study to establish QC ranges of new agents in accordance with CLSI M23, including presentation to the QC working group.

Disk Diffusion and Alternate Test Methods Development or Evaluation: Optimization or validation of non-standard antimicrobial testing approaches.

Method Correlation Studies: Comparison of new or alternate methods against reference standards (broth vs. disk, agar vs. broth, etc.).

Bacterial and Fungal Characterization and Identification Services

We apply state-of-the-art identification methods and molecular tools to ensure accurate characterization of your test organisms. Whether you are validating a novel antimicrobial or investigating treatment failures, we deliver precise results that align with your project goals. Our collaborative team approach means you get both the technical depth and the interpretive insight needed to move your program forward.

Culture Services

Isolation of a variety of organisms from a given test sample across matrices such as skin swab, fecal, urine, and tissue.

Bacterial and Fungal Identification Methods

• Bruker MALDI Biotyper
• 16S rRNA gene sequencing

Molecular Characterization (PFGE, PCR, Sequencing)

Our team is highly experienced in molecular biology techniques that support drug discovery and development:

• PCR of genes involved in resistance and/or target identification
• DNA sequencing for mutational analysis or 16S rRNA identification
• Bioinformatics to align sequences and compare to reference genes
• Pulsed field gel electrophoresis for analysis of patient isolates (treatment failures) and epidemiological typing (e.g., USA typing of S. aureus)

For advanced genomic insights, explore our dedicated genomic sequencing services. These complementary capabilities provide high-resolution data to uncover resistance mechanisms, track epidemiology, and support regulatory submissions.