![]() ![]() To provide preliminary information to the clinician regarding presumptive bacterial pathogens.It yields results much more quickly than culture, and is especially important when infection would make an important difference in the patient's treatment and prognosis examples are cerebrospinal fluid for meningitis and synovial fluid for septic arthritis To directly examine specimens submitted for microbiologic examination, e.g., body fluid or biopsy when infection is suspected.The Gram stain has been used for several purposes that include: In molecular microbiology laboratory, most identification is done using genetic sequences and other molecular techniques which are far more specific and information-rich than differential staining. Given that some organisms are Gram-variable (i.e., they may stain either negative or positive), and that some organisms are not susceptible to either stain used by the Gram technique, its true utility to researchers should be considered limited and specific. It is of extremely limited use in some instances and has been largely superseded by molecular techniques even in the medical microbiology laboratory. The Gram stain is not an infallible tool for diagnosis, identification, or phylogeny, however. Gram-positive cells, thick walled and lipid-poor, appear blue from retaining the original CV. This suggests Gram-negative bacteria are more "leaky," causing these thin-walled lipid-rich cells to lose their crystal violet (CV) stain and appear red from the counterstain. The mechanism further implies that solvent decolorization causes significant damage to the cell surfaces of Gram-negative bacteria and only limited damage to Gram-positive bacteria. The Gram stain easily divides bacteria into two groups, Gram-positive and Gram-negative, on the basis of their cell wall and cell membrane permeability. ![]() First described by Danish pathologist Christian Gram in 1884 and later slightly modified. , Although described more than a century ago, the Gram stain remains the most frequently used rapid diagnostic test, and in conjunction with various biochemical tests is the cornerstone of the clinical laboratory. Available from: Įffective utilization and understanding of the clinical bacteriology laboratory can greatly aid in the diagnosis of infectious diseases. Laboratory perspective of gram staining and its significance in investigations of infectious diseases. STAIN PRECIPITATE HOW TOHow to cite this URL: Thairu Y, Nasir IA, Usman Y. How to cite this article: Thairu Y, Nasir IA, Usman Y. Keywords: Positive culture, Bacteriological, Limitations and special samples The aim of this mini review is to analyze and discuss the clinical significance and limitations of reporting Gram staining results for sample meant for bacteriological investigations. This would carry a risk leading to inadequate antimicrobial therapy and potentially affecting patients' clinical course and mortality. On the other hand, there remains the possibility that Gram staining results do not match with the final identification of microorganisms. ![]() In recent reports, the impact of Gram staining results on patient mortality has been documented. It is therefore highly likely that the information provided by the Gram staining will help to assess the adequacy of preliminary diagnosis and antimicrobial therapy selected after collecting culture specimens and before final identification of the microorganism. The most important and primary test to perform directly on some special samples such as cerebrospinal fluid and positive cultures is Gram staining which serves as the most rapid and simplest test to characterize microorganisms. Isolation, identification of pathogenic microorganisms in cultures and subsequent antimicrobial susceptibility testing always assists in selecting appropriate antimicrobial agent and prevention of unnecessary complications. Precipitates will form and disappear.Clinical microbiology laboratory plays several important roles in the management of bacterial infections.
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