What is Antimicrobial Susceptibility Testing?
Antimicrobial Susceptibility Testing (AST) is a laboratory procedure used to determine how effective specific antimicrobial agents are against the bacteria or fungi isolated from a patient's infection. It informs healthcare providers about the most appropriate antibiotic therapy to use, ensuring that the treatment is both effective and minimizes the risk of resistance.
It helps in the
infection control process by identifying the most effective antimicrobial agents.
It aids in reducing the spread of resistant microorganisms.
It ensures proper patient care by guiding appropriate treatment decisions.
It minimizes unnecessary use of broad-spectrum antibiotics, thereby preserving their efficacy.
Disk Diffusion (Kirby-Bauer) Method: Antibiotic-impregnated disks are placed on an agar plate inoculated with the bacteria. The zone of inhibition around each disk is measured to determine susceptibility.
Broth Dilution: Dilutions of antibiotics are mixed with a standardized bacterial suspension in broth. The minimum inhibitory concentration (MIC) is determined by observing the lowest concentration that inhibits visible growth.
E-test: A strip impregnated with a gradient of an antibiotic is placed on an inoculated agar plate. The MIC is read where the bacterial growth intersects the strip.
Specimen Collection: Nurses collect specimens (e.g., blood, urine, swabs) correctly and promptly, ensuring they are transported to the lab under appropriate conditions.
Patient Education: Nurses educate patients on the importance of completing the prescribed antibiotic course and the risks of antimicrobial resistance.
Interdisciplinary Collaboration: Nurses work closely with physicians, pharmacists, and microbiologists to interpret AST results and implement appropriate treatment plans.
Monitoring: Nurses monitor patients for signs of antibiotic effectiveness and adverse reactions, reporting any concerns to the healthcare team.
Challenges in AST and Nursing
There are several challenges nurses may face regarding AST: Timely Results: Delays in receiving AST results can hinder prompt initiation of effective therapy.
Multidrug Resistance: Treating infections caused by multidrug-resistant organisms requires careful selection of antimicrobials based on AST results.
Resource Limitations: Limited access to advanced AST methods and lack of trained personnel can affect the quality of testing.
Future Perspectives
The future of AST in nursing looks promising with advancements in
rapid diagnostic techniques and
point-of-care testing. These innovations can significantly reduce the time required to obtain results, allowing for quicker adjustments to antimicrobial therapy and improved patient outcomes.
