Table of Contents
Does Streptococcus pneumoniae form endospores?
Streptococcus pneumoniae, or pneumococcus, is a Gram-positive, spherical bacteria, alpha-hemolytic (under aerobic conditions) or beta-hemolytic (under anaerobic conditions), aerotolerant anaerobic member of the genus Streptococcus. They are usually found in pairs (diplococci) and do not form spores and are non motile.
What are the characteristics of Streptococcus pneumoniae?
Streptococcus pneumoniae cells are Gram-positive, lancet-shaped cocci (elongated cocci with a slightly pointed outer curvature). Usually, they are seen as pairs of cocci (diplococci), but they may also occur singly and in short chains. When cultured on blood agar, they are alpha hemolytic.
Does Streptococcus pneumoniae have plasmids?
Plasmid deoxyribonucleic acid has been detected in three related laboratory strains of Streptococcus pneumoniae. Strains D39S, R36, and R36NC each contain a minimum of two copies per cell of a 2.0-megadalton plasmid (pDP1).
What kind of bacteria is Streptococcus pneumoniae?
Streptococcus pneumoniae are lancet-shaped, gram-positive, facultative anaerobic bacteria with 100 known serotypes. Most S. pneumoniae serotypes can cause disease, but only a minority of serotypes produce the majority of pneumococcal infections. Pneumococci are common inhabitants of the respiratory tract.
Does Streptococcus pneumoniae produce endotoxins or Exotoxins?
Streptococcus pneumoniae is one of the most common and most aggressive causes of pneumonia and sepsis, and it represents one of the most frequent and most disastrous pathogens in bacterial meningitis. A major exotoxin of Streptococcus pneumoniae is pneumolysin (24).
What does Streptococcus pneumoniae look like under a microscope?
Streptococcus pneumoniae bacteria are gram-positive cocci arranged in chains and pairs (diplococci) on microscopic examination. A green, α-hemolytic, zone surrounds S. pneumoniae colonies on blood-agar plates.
What is the structure of Streptococcus pneumoniae?
pneumoniae is roughly six layers thick and is composed of peptidoglycan with teichoic acid attached to approximately every third N-acetylmuramic acid. Lipoteichoic acid is chemically identical to the teichoic acid but is attached to the cell membrane by a lipid moiety.
How many competent specific protein are produced by Streptococcus pneumoniae?
Organized in ∼12 principal operons, the so-called late genes encode a core streptococcal set of 28 competence-specific proteins, which create a DNA processing pathway for efficient transport, preservation, and recombination of extracellular genome fragments.
Why is Streptococcus pneumoniae naturally competent?
The majority of the cells induced to competence take up DNA and act as recipients, whereas the rest release DNA and act as donors. These findings show that natural transformation in streptococci provides a natural mechanism for genetic recombination that resembles sex in higher organisms.
Streptococcus pneumoniae. Streptococcus pneumoniae (S. pneumoniae) are lancet-shaped, gram-positive, facultative anaerobic bacteria with over 90 known serotypes.
How big is a Streptococcus pneumoniae cell chain?
They are often found in pairs, although it is also possible to find shorter chains and single cells. These bacteria are classified as alpha hemolytic, which refers to how they break down red blood cells. Individual Streptococcus Pneumoniae bacterium usually measures between 0.5 and 1.25 micrometers in diameter.
How many people are carriers of Streptococcus pneumoniae?
Streptococcus pneumoniae. Pneumococci are common inhabitants of the respiratory tract and may be isolated from the nasopharynx of 5–90% of healthy persons, depending on the population and setting. Only 5–10% of adults without children are carriers. Among school-aged children, 20–60% may be carriers.
When does nasopharyngeal colonization of Streptococcus pneumoniae begin?
For the human body, the process of nasopharyngeal colonization of Streptococcus pneumoniae becomes established during the early stages of life.