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What else can I help you with?
Are Escherichia coli gram-negative?
Yes, E. coli are Gram negative.
Why do some antibiotics work better against gram positive then gram negative bacteria?
Part of describing the function of an antibiotic is stating whether it is effective against Gram-positive bacteria, Gram-negative bacteria or both. (There are other aspects such as whether there is effect on aerobic versus anaerobic bacteria (those that can versus cannot survive in the presence of oxygen), but I'll address that some other time).Some antibiotics have broad spectrum activity, being able to kill Gram-positive and Gram-negative bacteria. At first that might seem like a good thing, and indeed it is when you are treating an infection with an unknown bacterium. However, broad spectrum activity is not desirable when you know exactly what bacterium you are trying to eliminate. If possible, it's much better to target treatment more specifically against the offending bacterium for various reasons, such as to reduce the risk of resistance emerging in other bacterial groups.Some antibiotics are narrow spectrum. Some are most effective against Gram-positive or Gram-negative bacteria, with little activity against the other. In general, we want to use an antibiotic of the most narrow spectrum possible.
Why cant you gram stain e coli and salmonella?
Escherichia coli (E. coli) and Salmonella are both Gram-negative bacteria, which means they have a thinner peptidoglycan layer and an outer membrane that can prevent the crystal violet stain used in Gram staining from penetrating effectively. As a result, they do not retain the violet stain and appear pink after the counterstain is applied, indicating their Gram-negative status. Gram staining is still applicable to these bacteria; however, their Gram-negative characteristics are revealed rather than obscured.
Difference between the gram stain ans acid fast stain reactions of E. coli?
Gram staining is useful in separating bacteria into two groups: Gram positive or Gram negative. They are separated into these groups based on their cell wall structure. Gram positive bacteria contain a thick layer of peptidoglycan in their cell walls, while Gram negative bacteria contain a very small layer of peptidoglycan (15% or less of what Gram positive cell walls contain). A primary stain is added, such as Crystal Violet, that will stain all of the bacteria. Then, a mordant (such as iodine and potassium iodide) is added to form a complex between the peptidoglycan and the stain, which will make the cell more resistant to decolorization. Then, a decolorizing agent is added, which will remove the primary stain from Gram negative bacteria, but will cause the cell walls in Gram positive bacteria to dehydrate, and therefore, they will retain the primary stain. Finally, a counterstain (typically safranin) is added to distinguish Gram positive from Gram negative. Gram positive cells will be purple, and Gram negative cells will be red if Crystal Violet and Safranin are used.Acid-fast staining is entirely different. Is is used to detect species of bacteria in the genera Mycobacteria and Nocardia. These bacteria are resistant to typical staining procedures, such as Gram staining, due to a thick, waxy lipid layer in the cell wall composed of mycolic acid. Heating of the bacteria with a very strong stain such as carbol-fuchsin is necessary to "melt" this lipid layer, and force the stain through the cell wall. Once the bacteria has cooled, they will be incredibly resistant to decolorization. Non-acid fast bacteria do not contain this mycolic acid layer, and therefore, they will decolorize much easier, and are then stained with a counterstain to distinguish Acid-Fast bacteria from Non-Acid-Fast bacteria.
Why is EColi a gram negative bacteria?
E.coli is gram -ve and should stain pink in gram staining. The reason for its blue appearance is due to the over absorption of dye which can be due to either prolonged contact of dye or delay in washing or may be the concentration of soloution of dye is high
Is salmonella typhimurium gram positive?
It is gram negative
Are Escherichia coli gram-negative?
Yes, E. coli are Gram negative.
Escherichia these bacteria gram positive or negative?
Garm v-e
Is E Coli bacteria gram negative or gram positive?
the previous answer of gram positive rods is incorrect the correct answer is gram negative rods
How does a stained smear of S epi and E coli made from 7-day-old cultures would appear?
A 7-day-old culture may appear gram negative, when the organmisms are actually gram positive. Thus, S. epi would appear gram negative, and E. coli gram negative.
What bacteria is a gram negative?
One example of a gram-negative bacteria is Escherichia coli (E. coli). Gram-negative bacteria have a cell wall structure that includes an outer membrane, which is not present in gram-positive bacteria. This outer membrane contains lipopolysaccharides that contribute to the bacteria's resistance to certain antibiotics. Gram staining is a common technique used to differentiate between gram-negative and gram-positive bacteria based on their cell wall composition.
Is E-coli a gram negative cocci or rods?
a gram negative rod
Which bacilli are gram positive oxidase negative and catalase positive?
Streptobacillus is a gram negative, oxidase negative, catalase negative, non motile organism, and 0.3-0.7 µm by 1-5 µm in lengthEscherichia coliMost of the Enterobacteriaceae are Catalase Positive. E. coli is Catalase Positive and Oxidase Negative. Do not report the previous as an answer. For gram negative, catalase negative and oxidase negative rods, it is likely that you have bacteria of the Bacteroides genus.
What are E coli and Staphylococcus aureus classified as?
E. coli is a gram-negative bacteria.S. aureus is a gram-positive coccus. It is a coccus because its shape is round (from the Greek kokkos=grain).
How could you differentiate between e coli and staph epidermidis using a simple stain?
E.coli is a gram negative rod mostly isolated from urine while staph is a gram positive cocci. You can differentiate them by color. E. Coli is Pink which is negative while Staph is Purple with is positive.
What is the shape of E coli in gram staining?
It is a Gram negative rod-shaped bacterium
What is common use isolates gram negative enterics?
Commonly used isolates for gram negative enterics include E. coli, Salmonella, Shigella, and Klebsiella. These bacteria are often studied in microbiology labs due to their pathogenic potential and relevance to human health.
