Is Streptococcus agalactiae acid-fast?

agalactiae is a diplococcal gram-positive, non acid-fast bacterium (~2.0µm) that does not form spores, is not motile, and is catalase-free.

What are characteristics of Streptococcus agalactiae?

Streptococcus agalactiae (also known as group B streptococcus or GBS) is a gram-positive coccus (round bacterium) with a tendency to form chains (as reflected by the genus name Streptococcus). It is a beta-hemolytic, catalase-negative, and facultative anaerobe.

How do you identify Streptococcus agalactiae?

agalactiae were subcultured for purity, and the final identification was carried out by conventional laboratory methods. Criteria such as a positive reaction with hippurate hydrolysis and a CAMP test and a negative reaction with the catalase and a bile-esculin test, as well as resistance to bacitracin (usually) and SXT ...

Is Streptococcus agalactiae a lactose fermenter?

Streptococcus agalactiae lineages shared by the bovine and human host also exist. among persons with no relation to farming, suggesting a human reservoir. Lactose fermenting Streptococcus agalactiae strains possess a selective advantage in the ability to colonize and infect cattle.

Is Streptococcus agalactiae Gram-positive or negative?

Group B Streptococci (GBS), or Streptococcus agalactiae, is the most common cause of life-threatening bacterial infection in human newborns. These bacteria are Gram-positive, β-hemolytic, chain-forming cocci that are normal residents of the vaginal flora in 25% of healthy women [3].

Acid Fast Stain

Is Streptococcus agalactiae beta hemolytic?

Streptococcus agalactiae or group B streptococcus (GBS)—a gram-positive, β-hemolytic organism in the Streptococcus genus that carries the Lancefield group B antigen. GBS are encapsulated organisms and ten antigenically distinct capsular serotypes have been described (1a, 1b, II–IX).

Which Streptococcus is beta hemolytic?

Pyogenic β-hemolytic streptococci (including Group A, C and G Streptococcus) are some of the most important Gram-positive bacterial pathogens in human medicine. Although effective therapy is available, invasive streptococcal infections are associated with a significant disease burden.

Which streptococci are alpha-hemolytic?

Streptococcus pneumoniae and a group of oral streptococci (Streptococcus viridans or viridans streptococci) display alpha-hemolysis.

Can Streptococcus agalactiae grow on MacConkey Agar?

Hence, it does not grow on MacConkey agar (MA) due to the absence of blood as well as due to the presence of high concentration of bile in the medium which is inhibitory to the growth of S. pneumoniae.

Which bacteria are acid-fast?

Is Staphylococcus aureus acid-fast?

Mycobacterium sp. (acid-fast rods) and Staphylococcus aureus (non-acid-fast cocci).

Is Streptococcus pneumoniae acid-fast?

Nonmotile, acid-fast, non-sporing, Gram-positive rod.

Which of the following would best differentiate Streptococcus agalactiae from Streptococcus pyogenes?

118. Which of the following would best differentiate Streptococcus agalactiae from Streptococcus pyogenes? Hydrolysis of sodium hippurate, agalactiae is + and pyogenes -. 119.

Are all streptococci beta-hemolytic?

Some group A streptococci appear nonhemolytic; group B can manifest α-, β-, or even γ-hemolysis; most S pneumoniae are α-hemolytic but can cause β-hemolysis during anaerobic incubation.

What bacteria are gamma hemolytic?

Gamma-hemolysis

Enterococcus faecalis (formerly called "Group D Strep"), Staphylococcus saprophyticus, and Staphylococcus epidermidis display gamma hemolysis.

Is Streptococcus agalactiae anaerobic?

Strep agalactiae has a thick peptidoglycan cell wall, which takes in purple dye when Gram stained - so this is a gram-positive bacteria. It's non-motile and doesn't form spores, and also, it's a facultative anaerobe, meaning that it can survive in both aerobic and anaerobic environments.

What is the morphology of Streptococcus agalactiae?

Morphology of Streptococcus agalactiae

agalactiae are spherical or ovoid Gram-positive cocci of the size 0.6–1.2 µm in diameter. However, some species may develop rod-like cells depending on the growth conditions.

What type of hemolysis is Streptococcus pyogenes?

pyogenes is a gram-positive, β-hemolytic streptococcus that is catalase negative. More than 150 different strains have been identified based on different M-protein types. It is a group A streptococcus based on its carbohydrate structure, according to Lancefield typing of β-hemolytic strains.

Is Lactobacillus Gram-positive or negative?

Lactobacillus iners is the most prevalent bacterial species in the human vaginal microbiome, and there have been few reports of its Gram-negative stain appearances despite the fact that the genus Lactobacillus is universally described as Gram-positive.

What agar does Streptococcus grow on?

The streptococci are usually isolated on Blood agar. Blood agar is one of the most commonly used media in a clinical lab. It consists of an enriched agar base (Tryptic Soy agar) to which 5% sheep red blood cells have been added.

Is Streptococcus agalactiae motile?

The genus Streptococcus comprises a heterogeneous group of bacteria that have an important role in medicine and industry. These microorganisms are Gram-positive, cocci, 0.6-1.2 µm diameter, not motile, do not form spores, are catalase-negative and grow in pairs or chains [7].