Search results
Results from the WOW.Com Content Network
Gram stain (Gram staining or Gram's method), is a method of staining used to classify bacterial species into two large groups: gram-positive bacteria and gram-negative bacteria. It may also be used to diagnose a fungal infection. [1] The name comes from the Danish bacteriologist Hans Christian Gram, who developed the technique in 1884. [2]
Gram-negative bacteria are bacteria that, unlike gram-positive bacteria, do not retain the crystal violet stain used in the Gram staining method of bacterial differentiation. [1] Their defining characteristic is that their cell envelope consists of a thin peptidoglycan cell wall sandwiched between an inner ( cytoplasmic ) membrane and an outer ...
Gram-negative bacteria have a thin peptidoglycan layer which does not retain the crystal violet, so when safranin is added during the process, they stain red. The Mycoplasmataceae lack a peptidoglycan layer so do not retain crystal violet or safranin, resulting in no color. The Chlamydiaceae contain an extremely thin peptidoglycan layer ...
The Gram-negative cell wall contains a thinner peptidoglycan layer adjacent to the cytoplasmic membrane than the Gram-positive wall, which is responsible for the cell wall's inability to retain the crystal violet stain upon decolourisation with ethanol during Gram staining.
The bacterium S. moniliformis is a gram-negative pleomorphic rod occurring frequently in chains and tangled filaments with bulbous or Monilia-like swellings.The organism presents phenotypically as being facultatively anaerobic, non-motile, weakly ferments glucose and maltose, is catalase and oxidase-negative, does not reduce nitrate, and exhibits no growth on MacConkey agar.
In Berlin, in 1884, Gram developed a method for distinguishing between two major classes of bacteria. [1] This technique, known as Gram staining, continues to be a standard procedure of medical microbiology. This work gained Gram an international reputation. The staining method later played a major role in classifying bacteria. Gram was a ...
Pasteurella multocida is a Gram-negative, nonmotile, penicillin-sensitive coccobacillus of the family Pasteurellaceae. [1] Strains of the species are currently classified into five serogroups (A, B, D, E, F) based on capsular composition and 16 somatic serovars (1–16).
Chlamydia trachomatis (/ k l ə ˈ m ɪ d i ə t r ə ˈ k oʊ m ə t ɪ s /) is a Gram-negative, anaerobic bacterium responsible for chlamydia and trachoma. C. trachomatis exists in two forms, an extracellular infectious elementary body (EB) and an intracellular non-infectious reticulate body (RB). [2]