How does the Gram staining procedure help doctors to treat patients?
How does the Gram staining procedure help doctors to treat patients?
The main benefit of a gram stain is that it helps your doctor learn if you have a bacterial infection, and it determines what type of bacteria are causing it. This can help your doctor determine an effective treatment plan.
Why is the Gram stain test used in the medical field?
A Gram stain is used, along with a culture of the material from an infected site, to identify the cause of a bacterial infection. The Gram stain provides preliminary results on whether bacteria are present and the general type, such as the shape and whether they are Gram-positive or Gram-negative.
What is the relationship between Gram staining and antibiotics?
Any alteration in the outer membrane by Gram-negative bacteria like changing the hydrophobic properties or mutations in porins and other factors, can create resistance. Gram-positive bacteria lack this important layer, which makes Gram-negative bacteria more resistant to antibiotics than Gram-positive ones [5,6,7].
How is Gram staining used in the real world?
The Gram stain has been used for several purposes that include: To directly examine specimens submitted for microbiologic examination, e.g., body fluid or biopsy when infection is suspected.
Is Gram positive bacteria harmful?
Though gram-negative bacteria are harder to destroy, gram-positive bacteria can still cause problems. Many species result in disease and require specific antibiotics.
What antibiotics work against Gram-positive bacteria?
Antibiotics for gram-positive bacterial infections. Vancomycin, teicoplanin, quinupristin/dalfopristin, and linezolid.
Why is iodine used in Gram staining?
When iodine is applied, decolorizing time for all cells is longer than without iodine. Thus, iodine penetrates the cell and serves to form a dye-iodine precipitate, and since all cells are less permeable for the dye-iodine toward decolorizing agents, slower removal of it results.
What is the difference between a Gram-positive and gram negative bacteria?
Gram positive bacteria possess a thick (20–80 nm) cell wall as outer shell of the cell. In contrast Gram negative bacteria have a relatively thin (<10 nm) layer of cell wall, but harbour an additional outer membrane with several pores and appendices.
What disease is caused by Gram-positive cocci?
Streptococcus pyogenes is a gram-positive group A cocci that can cause pyogenic infections (pharyngitis, cellulitis, impetigo, erysipelas), toxigenic infections (scarlet fever, necrotizing fasciitis), and immunologic infections (glomerulonephritis and rheumatic fever).
Which of the following is the example of gram negative bacteria?
Examples include E. coli, Klebsiella aerogenes, Proteus mirabilis, Pseudomonas aeruginosa, Pseudomonas cepacia and other Pseudomonas species, Enterobacter, Acinetobacter, and non-pigmented strains of Serratia marcescens.
Which antibiotic is less effective against gram negative bacteria?
Many antibiotics, such as vancomycin, which like β-lactam antibiotics targets the cell wall peptidoglycan, are ineffective against Gram-negative bacteria, simply because they have chemical properties that do not allow them to utilize these pathways to effectively penetrate the outer membrane.
Why do antibiotics work better on Gram-positive bacteria?
Antibiotics: mode of action It is specific to bacteria because only bacteria have this polymer in their cell wall, and it is more effective against Gram positive bacteria because they have a much thicker layer of peptidoglycan in their cell wall than Gram negative bacteria.
Is it easier to treat gram negative or gram-positive bacteria?
Gram-positive bacteria don’t have this feature. Because of this difference, gram-negative bacteria are harder to kill. This means gram-positive and gram-negative bacteria require different treatments. Though gram-negative bacteria are harder to destroy, gram-positive bacteria can still cause problems.
Is cocci bacteria good or bad?
The Gram-positive cocci are the leading pathogens of humans. It is estimated that they produce at least a third of all the bacterial infections of humans, including strep throat, pneumonia, otitis media, meningitis, food poisoning, various skin diseases and severe types of septic shock.
What is the treatment for Gram-positive cocci?
Most infections due to Gram-positive organisms can be treated with quite a small number of antibiotics. Penicillin, cloxacillin, and erythromycin should be enough to cover 90 per cent of Gram-positive infections.
What is the purpose of a Gram stain?
A Gram stain is a test that checks for bacteria at the site of a suspected infection or in certain body fluids, such as blood or urine. These sites include the throat, lungs, and genitals, and in skin wounds. There are two main categories of bacterial infections: Gram-positive and Gram-negative.
What color is gram negative bacteria?
Gram negative organisms are Red. Hint; Keep your P’s together; Purple is Positive. Gram stains are never pink they are red or purple so you don’t destroy the rule; keep your P’s together. In microbiology bacteria have been grouped based on their shape and Gram stain reaction.
What is the most important step in the gram staining procedure Why?
The thickness of the smear used in the Gram stain will affect the result of the stain. The step that is most crucial in effecting the outcome of the stain is the decolorizing step.
Which is harder to treat gram-positive or negative?
What does Gram-positive bacteria cause?
Gram-positive cocci: Staphylococcus aureus is a gram-positive, catalase-positive, coagulase-positive cocci in clusters. S. aureus can cause inflammatory diseases, including skin infections, pneumonia, endocarditis, septic arthritis, osteomyelitis, and abscesses.
What is the difference between a gram positive and gram negative bacteria?
Gram positive bacteria have a thick peptidoglycan layer and no outer lipid membrane whilst Gram negative bacteria have a thin peptidoglycan layer and have an outer lipid membrane.
How is Gram staining used in the advanced bacteria project?
In part one, perform a gram stain on bacteria cultures to determine which are gram-negative and which are gram-positive. In part two, set up a controlled experiment to measure the effect of each type of antibiotic on each type of bacteria. Working with chemicals and bacteria can be hazardous.
What can a doctor do with a Gram stain?
Your doctor can use a gram stain to learn if bacteria are responsible for your symptoms and what types of bacteria are present. They may also order other tests to help diagnose your illness.
What does it mean when a Gram stain is negative?
If your gram stain results are negative, it means no bacteria were found in your sample. If they’re positive, it means bacteria were present. The main benefit of a gram stain is that it helps your doctor learn if you have a bacterial infection, and it determines what type of bacteria are causing it.
When to use Gram stain for meningitis treatment?
Gram’s stain examination is recommended for all patients suspected of having meningitis as it is fast, inexpensive, and fairly reliable. A positive result is useful in guiding initial antimicrobial therapy. Various reports of Gram’s stain sensitivity suggest a range from 50% to 90%.
How is the Gram stain used in microbiology?
Use of the gram stain in microbiology The Gram stain differentiates bacteria into two fundamental varieties of cells. Bacteria that retain the initial crystal violet stain (purple) are said to be “gram-positive,” whereas those that are decolorized and stain red with carbol fuchsin (or safranin) are said to be “gram-negative.”
Why do Gram positive bacteria retain their color?
The Gram stain procedure enables bacteria to retain color of the stains, based on the differences in the chemical and physical properties of the cell wall. 1. Gram positive bacteria: Stain dark purple due to retaining the primary dye called Crystal Violet in the cell wall. Example: Staphylococcus aureus.
What does it mean when your Gram stain is red?
If the bacteria was colored pink or red, it means you likely have a Gram-negative infection. Your results will also include information about the shape of the bacteria in your sample. Most bacteria are either round (known as cocci) or rod-shaped (known as bacilli).
What are the limitations of Gram negative staining?
The primary limitation of the technique is that it yields erroneous results if mistakes are made in the technique. Practice and skill are needed to produce a reliable result. Also, an infectious agent may not be bacterial. Eukaryotic pathogens stain gram-negative.