Introduction to Neo-Sensitabs

Neo-Sensitabs, developed by Rosco Diagnostica, are a specialized form of antimicrobial susceptibility testing tablets used in the disc diffusion method. These tablets are designed to assess the sensitivity of bacterial strains to various antibiotics, providing essential information that guides the selection of appropriate antimicrobial therapies. Unlike traditional paper discs, Neo-Sensitabs are tablet-based, offering enhanced accuracy, stability, and consistency in testing.

How Neo-Sensitabs Work

Neo-Sensitabs operate on the same principles as the standard disc diffusion method but with some key differences that improve the precision and reliability of the results.

1. Preparation of Bacterial Inoculum

Before testing, a pure culture of the bacteria to be tested is grown and suspended in a saline solution. The suspension is then adjusted to a standardized turbidity, typically using the McFarland standard, to ensure consistent and comparable results across tests.

2. Inoculation of Agar Plate

A Mueller-Hinton agar plate, which is the standard medium used for susceptibility testing, is inoculated with the bacterial suspension. The bacteria are spread uniformly across the agar surface using a sterile swab, creating a “lawn” of bacterial growth.

3. Application of Neo-Sensitabs

Neo-Sensitabs are then applied to the surface of the inoculated agar plate. The tablets are placed at appropriate intervals to prevent the overlap of inhibition zones, which could interfere with accurate measurement. The tablets are easy to handle and apply, and their standardized size and shape help ensure consistent diffusion of the antibiotic into the agar.

4. Incubation

The inoculated agar plate with Neo-Sensitabs is incubated at 35-37°C for 16-18 hours. During incubation, the antibiotic from the Neo-Sensitabs diffuses radially outward through the agar. This diffusion creates a gradient of antibiotic concentration, with the highest concentration closest to the tablet.

5. Interpretation of Results

After incubation, the agar plate is examined for zones of inhibition around each Neo-Sensitab. These zones indicate where bacterial growth has been inhibited by the antibiotic. The diameter of each zone is measured in millimeters and compared to standardized interpretive criteria to classify the bacteria as susceptible, intermediate, or resistant to the tested antibiotic.

Benefits of Using Neo-Sensitabs

Neo-Sensitabs offer several advantages over traditional paper-based discs in bacterial testing:

• Enhanced Consistency: The tablet format of Neo-Sensitabs ensures a more uniform release of antibiotics, leading to consistent and reproducible results across different tests and laboratories.
• Increased Stability: Neo-Sensitabs are less prone to degradation over time compared to paper discs, which can lose potency. This makes them more reliable for long-term storage and use.
• Wide Range of Antibiotics: Rosco Diagnostica provides Neo-Sensitabs for a broad spectrum of antibiotics, including single and combination therapies, which are essential for testing various bacterial strains and resistance mechanisms.
• Clear Labeling: Neo-Sensitabs are clearly labeled, reducing the risk of misidentification and errors during testing, which is critical in a busy laboratory environment.
• Broad Application: Neo-Sensitabs can be used to test a variety of bacterial pathogens, including Gram-positive and Gram-negative bacteria, and are suitable for routine clinical testing as well as research purposes.

Applications in Clinical Microbiology

Neo-Sensitabs are extensively used in clinical microbiology laboratories to determine the susceptibility of bacterial pathogens to antibiotics. They play a critical role in:

• Guiding Antibiotic Therapy: By accurately determining the susceptibility of bacteria to different antibiotics, Neo-Sensitabs help clinicians choose the most effective treatment, reducing the risk of treatment failure and the development of resistance.
• Monitoring Antibiotic Resistance: Neo-Sensitabs are valuable tools for tracking trends in antibiotic resistance, enabling healthcare facilities to adjust their antibiotic use policies accordingly.
• Supporting Public Health Initiatives: By providing reliable data on bacterial susceptibility, Neo-Sensitabs contribute to broader efforts to combat antibiotic resistance at both local and global levels.