CHROMagar™ COL-APSE base

For Detection of Colistin-Resistant Gram-Negative Bacteria (COL-R)

CHROMagar™ COL-APSE is a selective and differential chromogenic culture medium designed for the detection and presumptive identification of colistin-resistant Gram-negative bacteria (COL-R), including those harboring plasmid-mediated mcr genes (e.g., mcr-1) and chromosomal resistance mechanisms. With clear colony color differentiation and high selectivity, it is ideal for colonization screening, surveillance, and resistance tracking in clinical, veterinary, food, and environmental microbiology.

Manufactured under ISO 9001 and ISO 13485 standards, this medium provides sensitive detection (down to 10 CFU/mL) and simplifies the isolation and identification of multiple COL-R species in mixed samples.

🔹 Key Features & Benefits

• ✅ Species-level differentiation:
  • COL-R E. coli: Dark pink to reddish
  • COL-R Klebsiella, Enterobacter, Citrobacter: Metallic blue
  • COL-R Pseudomonas: Translucent cream to green
  • COL-R Acinetobacter: Cream, opaque
• ✅ High sensitivity: Detects as few as 10 CFU/mL, allowing early identification from low-burden samples.
• ✅ Plasmid-mediated resistance detection: Suitable for screening bacteria carrying mcr-1 to mcr-5 and novel resistance genes.
• ✅ Flexible sample use: Validated for clinical rectal/perineal swabs, stool, food, animal feed, livestock, and environmental matrices.
• ✅ Supports AMR surveillance: Ideal for hospital screening, infection control, and One Health programs targeting zoonotic or environmental resistance reservoirs.

🔹 Colony Appearance

🔹 Intended Use

CHROMagar™ COL-APSE is intended for:

• Qualitative detection of gastrointestinal colonization with colistin-resistant Gram-negative bacteria from:
  • Rectal/perineal swabs
  • Stool samples
  • Livestock feces and feed
  • Water and environmental surfaces
• Surveillance and infection prevention programs in healthcare and veterinary settings.
• Early warning tool for potential outbreaks and antimicrobial resistance detection.

⚠️ Not intended to diagnose infection or guide treatment decisions. Confirmatory testing, susceptibility profiling, and molecular typing should follow positive results.

🔹 Clinical Background

Colistin (polymyxin E) is a last-line antibiotic used to treat multidrug-resistant Gram-negative infections. Colistin resistance, particularly through plasmid-mediated mcr genes, poses a growing threat in hospitals, agriculture, and the environment. Conventional detection methods are slow or non-specific.

CHROMagar™ COL-APSE provides a fast, reliable method to identify and differentiate colistin-resistant organisms, critical to implementing infection control and stewardship protocols.

📌 “CHROMagar™ COL-APSE enables detection of low-level colistin resistance, including mcr-positive isolates, from mixed flora within 18–24 hours.”

(ECCMID 2017: Abdul Momin & Wareham)

🔹 Test Procedure

1. Sample Types: Rectal/perineal swabs, stools, animal feed, environmental water, food products
2. Inoculation: Direct streaking or surface spreading
3. Incubation:
   • Temperature: 35–37 °C
   • Time: 18–24 hours
   • Atmosphere: Aerobic
4. Interpretation:
   • Observe colony color and morphology to presumptively identify species

🔹 Ordering Information

🔹 Storage & Shelf Life

• Storage: 2–8 °C (refrigerated, dry, sealed)
• Shelf Life: Up to 24 months from date of manufacture
• Prepared Plates: Follow manufacturer guidance for use-by dates

CHROMagar™ COL-APSE offers a sensitive, specific, and visually distinct solution for detecting colistin-resistant Gram-negative bacteria, including plasmid-mediated mcr gene carriers. With its ability to differentiate multiple pathogens by colony color and detect even low bacterial loads, it is a critical tool for AMR surveillance, infection control, and global One Health strategies against antimicrobial resistance.