Diagnosis Infectious Disease - Choosing the Right Treatment

7 important questions on Diagnosis Infectious Disease - Choosing the Right Treatment

Why is it essential to identify pathogens isolated from clinical specimens, and what role does it play in guiding antimicrobial therapy?

Identifying pathogens is essential to confirm medical diagnoses and guide antimicrobial therapy. It helps in tailoring treatment strategies based on current experience and practices.

Under what circumstances are decisions about appropriate antimicrobial therapy made on a case-by-case basis, and which types of pathogens fall into this category?

Decisions are made on a case-by-case basis for pathogens with common antimicrobial drug resistance (e.g., gram-negative enteric bacteria), those causing life-threatening diseases (e.g., Neisseria meningitidis causing meningitis), and those requiring bactericidal drugs to prevent disease progression.

What is the minimum inhibitory concentration (MIC), and how is it determined in traditional microbiological practice?

MIC is the smallest amount of an antimicrobial agent needed to completely inhibit the growth of a tested organism in vitro. In traditional practice, a series of culture tubes with increasing concentrations of the antimicrobial agent is inoculated, and the MIC is the lowest concentration that inhibits growth.
  • Higher grades + faster learning
  • Never study anything twice
  • 100% sure, 100% understanding
Discover Study Smart

How is the modern determination of MIC typically performed in clinical microbiology laboratories?

Modern MIC determination often uses microliter amounts of media and reagents. A microtiter method with twofold dilutions of antibiotics in medium inoculated with the test organism is commonly employed. Automated instruments in clinical microbiology laboratories facilitate routine MIC determinations.

Describe the disk diffusion test and its role in measuring antimicrobial susceptibility.

The disk diffusion test involves inoculating a Petri plate with an agar medium and spreading a pure culture of the suspected pathogen. Antimicrobial agents infused into filter-paper disks are placed on the agar surface, and during incubation, the agents diffuse, creating a zone of inhibition. The diameter of this zone is proportional to the concentration and effectiveness of the antimicrobial agent.

What is the epsilometer test (Etest®), and how does it contribute to measuring antimicrobial susceptibility?

The epsilometer test (Etest®) uses a plastic strip infused with a predefined concentration gradient of an antimicrobial agent. When applied to an inoculated agar plate, an elliptical zone of inhibition develops. The concentration of the antimicrobial agent is read at the point where the ellipse edge intersects the precalibrated test strip, providing a precise MIC.

How do hospital infection-control microbiologists use antibiograms, and what role do these reports play in monitoring pathogens and antibiotic resistance?

Hospital infection-control microbiologists use antibiograms, generated by examining susceptibility data, to produce periodic reports. Antibiograms define the susceptibility of clinically isolated organisms to antibiotics, helping monitor control of known pathogens, track the emergence of new pathogens, and identify antibiotic resistance at the local level.

The question on the page originate from the summary of the following study material:

  • A unique study and practice tool
  • Never study anything twice again
  • Get the grades you hope for
  • 100% sure, 100% understanding
Remember faster, study better. Scientifically proven.
Trustpilot Logo