CHROMagar™ MH Orientation

Chromogenic Mueller Hinton Medium for Simultaneous Identification and Antimicrobial Susceptibility Testing

CHROMagar™ MH Orientation is an innovative chromogenic Mueller Hinton agar, uniquely designed to enable simultaneous presumptive identification and antimicrobial susceptibility testing (AST) directly from the primary culture. This 2-in-1 medium streamlines workflows by combining species-level chromogenic differentiation with E-test or disk diffusion compatibility—offering same-day results for identification and susceptibility, significantly faster than traditional protocols.

This medium is ideal for respiratory and urinary samples, especially from critically ill or hospitalized patients, helping clinicians adjust therapy more rapidly to improve outcomes.

🔹 Key Features & Benefits

• ✅ 2-in-1 Functionality:
  Enables chromogenic species differentiation and AST (e.g., with E-test or disk diffusion) directly from the same plate.
• ✅ Rapid Results:
  Identification and susceptibility profiles are available after 18–24 hours—no need for subculturing to a separate MH plate.
• ✅ Clear, Color-Based Differentiation:

  Organism	Colony Appearance
  E. coli	Dark pink to red
  Klebsiella, Enterobacter, Citrobacter	Metallic blue

• ✅ Precise AST Zone Readability:
  Chromogenic background improves visualization of inhibition zones, supporting accurate MIC readings.
• ✅ Validated Performance:
  Evaluated by AB BIODISK and ECCMID research groups using 20+ antibiotics with excellent correlation to traditional MH agar.

🔹 Clinical Applications

1. Ventilator-Associated Pneumonia (VAP)
   Direct inoculation of respiratory specimens onto CHROMagar™ MH Orientation provides rapid identification and susceptibility to support timely adjustments in therapy.

   Cercenado et al., ECCMID 2009: “Rapid AST from chromogenic agar improves clinical decisions in ICU patients with VAP.”

2. Urinary Tract Infections (UTIs)
   For typical bacteriuria levels (10³–10⁵ CFU/mL), urine samples can be plated directly. Color-coded identification and AST results support confirmation or adjustment of empirical therapy.
3. Bacteremia / Rectal Screening
   Enables AST screening for fluoroquinolone-resistant Enterobacteriaceae and other MDR organisms in bloodstream or colonization studies.

🔹 Intended Use

CHROMagar™ MH Orientation is intended for:

• Qualitative detection and presumptive identification of key Gram-negative bacteria in urine and respiratory samples
• Direct antimicrobial susceptibility testing (e.g., E-test or disk diffusion)
• Use in clinical laboratories for:
  • Rapid UTI diagnosis
  • ICU/VAP patient screening
  • Outbreak investigations and AST profiling

⚠️ Not for final diagnosis or therapeutic guidance. Confirmatory ID and full AST using standard protocols are recommended.

🔹 Test Procedure

1. Sample Types: Urine, respiratory tract samples, rectal swabs
2. Inoculation: Plate sample directly onto CHROMagar™ MH Orientation
3. AST: Apply E-test strips or antibiotic disks after streaking
4. Incubation:
   • Temperature: 35–37 °C
   • Time: 18–24 hours
5. Interpretation:
   • Identify based on colony color
   • Measure inhibition zones as per CLSI/EUCAST

🔹 Ordering Information

🔹 Storage & Shelf Life

• Storage: 2–8 °C (sealed, dry)
• Shelf Life: Up to 24 months
• Prepared Media: Use within validated expiration period

🔹 Scientific Publications

• Huachos-Vegas et al., 2023 – Rapid ID and AST in bacteriuric urine using CHROMagar™ MH Orientation (Peru)
• Akbi et al., 2021 – Direct disk diffusion testing in bloodstream infections
• Hintze et al., 2018 – Fluoroquinolone resistance detection in rectal swabs prior to prostate biopsy

CHROMagar™ MH Orientation is a powerful diagnostic tool that bridges identification and susceptibility testing in a single step. With its chromogenic capabilities and compatibility with AST methods, it reduces time-to-result and improves workflow efficiency, especially in high-priority clinical scenarios like UTIs and VAP.