Diagnostic Medical Microbiology Flashcards
What are the laboratory procedures in diagnosing microbiological diseases?
Culture
Morphological identification
Antigen or nucleic acid testing
Testing for markers of antibody/Cell-mediated response
In morphological identification for diagnosis of microorganisms, what are common specimens that can be used?
Sputum samples
Tissue sections
In this procedure of diagnosing microbiological diseases, staining techniques coupled with microscopy (light, occasionally electron) are used.
Morphological identification
This procedure of diagnosing microbiological diseases makes use different selective and differential media to isolate putative causative agents.
Culture and identification
These diagnostic procedures may involve enzymes, immunoassays, PCR and sequencing in identifying causative agents of disease.
Antigen or nucleic acid testing
What are the factors affecting test results?
Timing and care with which specimen is collected and transported
Quality of specimen
Technical proficiency and expertise of lab personnel
This factor affecting results of test mainly concerns active precautions to ensure the absence of contaminants in the sample allowing reliable results.
Quality of specimen
T/F. Tentative diagnosis cannot be made and clinicians have to wait until microbiological assessment results are available.
False. Tentative diagnosis should be made instead of waiting until lab results are back. Tentative diagnosis usually are informed by other results such as physical exams, and quick blood tests.
T/F. Clinicians should inform lab staff of the tentative diagnosis.
True. This allows the lab staff to focus on certain aspect of the microbiological testing procedure such as focusing on prospective/candidate causative agents based on the tentative diagnosis.
T/F. Clinicians can start treatment already despite the lack of definitive results from the microbiological tests currently underway.
True. Clinicians can start treatment with drugs aimed at the potential causative organism.
What is the significance of the lab staff informing the clinician as results are obtained?
Allows clinician to reevaluate diagnosis and clinical course of the patient.
What are the important facets of specimen and its collection in the context of medical microbilogy?
Quantity of material must be adequate
Specimen must be representative of the infectious process
Contamination must be avoided
Specimens must be taken to the lab and examined promptly
Must be meaningful to diagnose infections before antimicrobial drugs are administered
This methods refers to search for microbial or virus antigens using fluorescent antibody, ELISA, and so on.
Antigen assays
This method refers to search for pathogen genes by gene amplification.
Molecular assays
This refers to a series of tests aimed to enrich, isolate, and identify causative agents from cultures of clinical samples such as blood, feces, etc.
Growth-dependent microbiology