Gram stain


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Related to Gram stain: Gram negative, Gram positive

Gram stain

 (grăm) also Gram's stain (grămz)
n.
A staining technique used to classify bacteria in which a bacterial specimen is first stained with crystal violet, then treated with an iodine solution, decolorized with alcohol, and counterstained with safranin. Because of differences in cell wall structure, gram-positive bacteria retain the violet stain whereas gram-negative bacteria do not. Also called Gram's method.

[After Hans Christian Joachim Gram (1853-1938), Danish physician.]
ThesaurusAntonymsRelated WordsSynonymsLegend:
Noun1.Gram stain - a staining technique used to classify bacteria; bacteria are stained with gentian violet and then treated with Gram's solution; after being decolorized with alcohol and treated with safranine and washed in water, those that retain the gentian violet are Gram-positive and those that do not retain it are Gram-negative
staining - (histology) the use of a dye to color specimens for microscopic study
References in periodicals archive ?
The kappa coefficient value showing the strength of agreement between the results of direct microscopy using Gram stain and culture in this study was 0.667.
Call time, the time required for positive Gram stain results to be phoned to a caregiver, was obtained by reviewing the culture work card in the electronic medical record.
Random access processing of gram stain slides provides high-volume laboratories an ideal mix of standardization, labor-efficiency, and throughput.
Furthermore, the rate of chorioamnionitis was 20% in the vaginal treatment group, compared with 9% in the oral treatment group, 7% in the intermediate Gram stain group, and 10% in the controls.
No high-quality studies specifically address the utility of sputum Gram stain or culture in the assessment or treatment of community-acquired pneumonia (CAP) or nursing home-acquired pneumonia (NHAP).
After two of these episodes, the hospital began pretransfusion Gram staining and culturing of all platelets but did not delay platelet transfusion awaiting Gram stain or culture results.
Criteria used for a definitive diagnosis of ABM in our study included a positive CSF culture with/without a positive Gram stain and/or a positive LAT along with at least one of the classical clinical manifestations of ABM and any one of the features of meningeal inflammation: a) CSF cell count >10 cells/[mm.sup.3] with predominant polymorphonuclear neutrophils, b) CSF protein >45 mg%, and c) CSF glucose <40 mg%.
We can start with understanding how information supplied by the Gram stain is reported on the Critical Values Telephone Call when we report initial positive blood cultures.
Results: Analysis of 267 CSF samples obtained from suspected cases of acute bacterial meningitis revealed 94 per cent concordance in results for conventional (Gram stain and culture) and molecular methods.
Tissue culture from secretions from both patients showed gram-positive cocci in clusters on the Gram stain, and subsequent cultures yielded MRSA.
Appropriate antibiotics should be started as quickly as possible and targeted to the most likely pathogens, based on the cerebrospinal fluid (CSF) Gram stain. Empiric antibiotics are indicated in the presence of purulent meningitis with a negative Gram stain or when there is a delay in obtaining CSF.