What does a positive indole test mean?

What does a positive indole test mean?

Like many biochemical tests on bacteria, results of an indole test are indicated by a change in color following a reaction with an added reagent. A positive result is shown by the presence of a red or red-violet color in the surface alcohol layer of the broth. A negative result appears yellow.

Is Streptococcus oxidase positive or negative?

Most streptococci are oxidase-negative and catalase-negative, and many are facultative anaerobes (capable of growth both aerobically and anaerobically).

Is E coli oxidase positive or negative?

E. coli bacteria are among the few species of lactose (LAC)-positive, oxidase-negative, gram-negative rods that are indole positive. Due to the infrequent isolation of non-E. coli strains that are indole positive, the spot indole test has been used for the rapid, presumptive identification of E.

What organisms are oxidase positive?

Oxidase Positive Organisms: Pseudomonas, Neisseria, Alcaligens, Aeromonas, Campylobacter, Vibrio, Brucella, Pasteurella, Moraxella, Helicobacter pylori, Legionella pneumophila, etc.

Is Gram positive bacteria harmful?

Usually, gram-positive bacteria are the helpful, probiotic bacteria we hear about in the news, like LAB. They are the happy ones that live in our gut and help us digests food (Behnes, et al; 2013). Gram-negative bacteria, by coincidence, are usually thought of as the nasty bugs that can make us sick and can be harmful.

What infections are gram positive?

Infections caused by gram-positive bacteria such as methicillin-resistant Staphylococcus aureus (MRSA), vancomycin-resistant enterococci (VRE), and Clostridium difficile are among the most common multidrug-resistant infections in the United States [1].

Is E coli gram positive?

Escherichia Coli is a Common Intestinal Bacteria. E. coli is a Gram negative anaerobic, rod-shaped, coliform bacteria of the genus Escherichia, commonly found in the lower intestine of humans and animals. Most varieties are harmless.

Is Gram positive cocci serious?

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 disease is caused by Gram positive cocci?

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.

Can Gram positive cocci be treated?

Telavancin. Telavancin is a once-daily, intravenous, lipoglycopeptide antibiotic approved in the USA for the treatment of acute bacterial skin and skin structure infections due to Gram-positive pathogens and has recently received approval for the treatment of HAP caused by these pathogens.

Is Gram positive cocci an STD?

Health24. Is the present of gram positive cocci clusters a sign. of STI ? Staphylococcus aureus is a bug but it is not usually sexually transmitted.

Is cocci bacteria good or bad?

5 Types of Bacteria According to Gram Staining: Coccus – These are rounded or spherical in shape and may occur in chains or clusters. These occurs abundantly in the environment and also as a normal commensal on the human body (in nostrils, skin, oral cavity and genitals).

What is an example of cocci bacteria?

Cocci appear as single cells (coccus), pairs (diplococci), chains (streptococci), clusters of four cells (tetrads), irregular clusters (staphylococci), or large cuboid clusters (sarcinae). Examples of sphere-shaped cocci include: Aerococcus urinae (causes urinary tract infections and urosepsis)

What antibiotic is used to treat 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.

Is Gram-positive cocci the same as MRSA?

MRSA bacteria usually show resistance to many antibiotics. Because MRSA is so antibiotic resistant (drug-resistant), it is termed a “superbug” by some investigators. This superbug is a variation of an already recognized human pathogen, S. aureus, gram-positive bacteria that occur in grape-like clusters termed cocci.

What antibiotics work against Gram-positive bacteria?

New agents available include quinupristin/dalfopristin and line-zolid with activity against most resistant gram-positive bacteria. Promising new drugs that may reach the market in the near future include daptomycin and oritavancin.

Where do you get Gram-positive cocci?

Anaerobic gram-positive cocci and microaerophilic streptococci can be responsible for 4% to 15% of isolates from blood cultures of patients with clinically significant anaerobic BSI. The most common associated sources are oropharyngeal, pulmonary, female genital tract, abdominal, and skin and soft-tissue infections.

What does gram-positive cocci look like?

Gram-positive cocci are circular or oval in shape. The term “cocci,” which means sphere, indicates the bacteria are generally round.

Is Gram-positive or negative more dangerous?

Gram-positive bacteria cause tremendous problems and are the focus of many eradication efforts, but meanwhile, Gram-negative bacteria have been developing dangerous resistance and are therefore classified by the CDC as a more serious threat.

What does gram positive and negative mean?

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. The Gram staining technique was developed in 1884 by Danish bacteriologist Hans Christian Gram1.

Why is it important to know Gram positive or negative?

If bacteria are present, this test can also help your doctor learn if the bacteria are gram negative or gram positive. The difference between gram-negative and gram-positive bacteria can affect their recommended treatment plan. Gram stains can be performed on various types of specimens, including: blood.

Can Gram positive bacteria cause sepsis?

Sepsis is a multi-step process that involves an uncontrolled inflammatory response by the host cells that may result in multi organ failure and death. Both gram-negative and gram-positive bacteria play a major role in causing sepsis.

Can Gram positive bacteria produce endotoxin?

Since gram positive bacteria are made of peptidoglycan, they do not produce endotoxins. The outer membrane of gram negative bacteria is made up of lipopolysaccharide (LPS) layer which acts as an endotoxin. Whereas , The gram postive bacteria doesnot produce LPS layer (endotoxin).

What is the most common site for infection in the body that leads to sepsis?

Know the Risks. Without timely treatment, sepsis can rapidly lead to tissue damage, organ failure, and death. Almost any type of infection can lead to sepsis. Infections that lead to sepsis most often start in the lung, urinary tract, skin, or gastrointestinal tract.

How do you know if your body is fighting an infection?

However, some general symptoms of a bacterial infection include: fever. feeling tired or fatigued. swollen lymph nodes in the neck, armpits, or groin.