Aerobic C&S Stool Culture and Susceptibility Testing - MIC
Test Code
C71
Also Known As
No data available
Test Parameters Included
No data available
Department
MICROBIOLOGY
Methodology
Automated Culture and Susceptibility Testing (MIC)
This test employs an Automated Culture and Susceptibility Testing system to identify specific pathogenic bacteria in a stool sample and determine their susceptibility to antibiotics. The process involves:
* Automated Inoculation of Selective Media: The stool sample (or a rectal swab) is automatically inoculated onto various selective and differential culture media specifically designed to isolate common enteric (intestinal) bacterial pathogens (e.g., MacConkey, Hektoen Enteric Agar, XLD Agar, Salmonella-Shigella Agar). These media suppress the growth of normal gut flora while promoting the growth of pathogens.
* Automated Incubation: Inoculated plates are automatically transferred to an incubator at a specific temperature (typically 35-37°C) for a defined period (usually 18-24 hours).
* Automated Growth Detection & Colony Selection: Automated systems use imaging or other technologies to detect growth. If colonies suspicious of pathogenic bacteria appear, the system (or a technologist in conjunction with the system) identifies and selects these for further testing.
* Automated Identification (ID): Pure colonies of suspected pathogens are isolated. Automated systems then perform rapid biochemical tests or mass spectrometry (e.g., MALDI-TOF) to accurately identify the specific bacterial species (e.g., Salmonella spp., Shigella spp., Campylobacter spp., diarrheagenic Escherichia coli).
* Automated Susceptibility Testing (AST) - MIC: Once the pathogenic bacteria are identified, the automated system prepares a standardized bacterial suspension and performs susceptibility testing. This involves exposing the bacteria to various concentrations of different antibiotics. The system then measures the Minimum Inhibitory Concentration (MIC) for each antibiotic. The MIC is the lowest concentration of an antibiotic that prevents visible growth of the bacterium.
* Automated Interpretation: The MIC values are then automatically interpreted by the system (based on established clinical breakpoints from organizations like CLSI - Clinical and Laboratory Standards Institute) to determine if the isolate is Susceptible (S), Intermediate (I), or Resistant (R) to each tested antibiotic.
This automated approach offers rapid, standardized, and highly accurate results for both bacterial identification and antibiotic susceptibility, crucial for guiding effective antibiotic therapy for gastrointestinal infections.
Sample Required
STOOL (Fresh Random Stool or Rectal Swab in Transport Media)
* Fresh Random Stool: The preferred sample is a fresh, spontaneously passed stool specimen (not from toilet water). It should be collected in a clean, dry, leak-proof container with a tight-fitting lid.
* Quantity: At least 5-10 grams (a walnut-sized portion) is typically required.
* Avoid Contamination: Instruct the patient to avoid contaminating the sample with urine or toilet paper.
* Rectal Swab: For infants, critically ill patients, or when fresh stool is unavailable, a rectal swab collected in appropriate transport media (e.g., Cary-Blair medium) can be used. The swab should be inserted 2-3 cm past the anal sphincter and rotated to sample crypts.
* Transport Media: If transport to the lab is delayed, the sample should be placed in a suitable transport medium (e.g., Cary-Blair medium) to preserve the viability of pathogens and prevent overgrowth of normal flora. This is particularly important for Shigella and Campylobacter.
* Timely Transport/Refrigeration: The specimen should be transported to the laboratory as soon as possible. If transport media is not used, the sample should be processed within 2 hours or refrigerated at 4°C for up to 24 hours, though immediate processing is always best for stool.
Preparation
Proper collection and timely transport are critical to ensure the viability of pathogens and prevent overgrowth of commensal flora. * Patient Instructions: Provide clear instructions for collecting a ... Read more
Schedule Report
72 Hours
Emergency Report
Yes
Frequently Asked Questions
No data available
Test Description
- High-end laboratory & medical equipment.
- Outstanding doctor team.
- Personalized care & high-quality service.
- Tailormade health screening packages.