We reviewed 194 revision arthroplasties of the hip and knee performed over a ten-year period. The results of intraoperative Gram staining were available in 169 (87%). Thirty-two were found to be infected (11 hips and 21 knees) and 137 had no evidence of infection. Intraoperative Gram staining was negative in all 169 cases. The method therefore had a sensitivity of 0% for detecting infection. We...

Bacteria are fundamentally divided into two groups, Gram-positive and -negative, based on the chemical and physical properties of their cell walls. The classic Gram stain reaction permits the useful distinction between Gram-positive and -negative bacteria. Gram staining results largely affect the initial classifi cation of an unknown bacterium and the selection of follow-up identifi cation proc...

Rhodes' silver-plating technique for staining flagella was tested for its reliability and convenience as a routine procedure in the clinical laboratory. Modifications were made in the stain preparation and the procedure of staining and were tested with smears of known motile gram-negative nonfermentative bacilli. The stain has proved to be accurate and reliable and can be easily utilized with a...

The Danish microbiologist Hans Christian Gram developed a staining technique (1884) that classifies most bacteria into two large groups that are referred to eponymously, as Gram-positive and Gram-negative bacteria (1). His stain is still used in medical microbiology labs today, and because of its explanatory power, this classification is the most commonly used descriptor of a particular bacteri...

Crystal violet (hexamethyl-para-rosaniline chloride) interacts with aqueous KI-I2 during the Gram stain via a simple metathetical anion exchange to produce a chemical precipitate. There is an apparent 1:1 stoichiometry between anion (I-) and cation (hexamethyl-para-rosaniline+) during the reaction and, since the small chloride anion is replaced by the bulkier iodide, the complex formed becomes ...

Francisella philomiragia is a Gram-negative coccobacillus, which very rare human opportunistic pathogen causing pneumonia and systemic infection. It difficult to identify this bacterium through conventional Gram-staining biochemical methods due an amorphous Gram stain appearance after 24 h culture its relatively fastidious slow growth giving weak and/or delayed reactions in tests. often misiden...

BACKGROUND Brachyspira associated diarrhea is a re-emerging concern for Canadian swine producers. To identify critical control points for reducing the impact of Brachyspira on production, improved diagnostic tools and a better understanding of the on-farm epidemiology of these pathogens are required. A cross-sectional study was conducted for the detection of Brachyspira on a commercial, two-sit...

We compared the diagnostic value of an enzyme immunoassay method for detection of gonococcal antigen in genital secretions with culture results and direct Gram stain for Neisseria gonorrhoeae in 1,171 men and 723 women attending a sexually transmitted disease clinic. When compared with culture results in men, the immunoassay provided a sensitivity of 94% and a specificity of 98% and was essenti...