What is the Difference Between Streptococcus Pneumoniae and Streptococcus Pyogenes

The key difference between Streptococcus pneumoniae and Streptococcus pyogenes is that Streptococcus pneumoniae is a bacterial species that causes pneumonia in humans, while Streptococcus pyogenes is a bacterial species that causes pharyngitis, cellulitis, and erysipelas in humans.

Streptococcus is a genus of gram-positive coccus or spherical bacteria. Most Streptococci are oxidase negative, catalase-negative, and facultative anaerobes. The species of this genus have been found to be part of the salivary microbiome. Currently, over 50 species have been categorized under this genus. Streptococcus pneumoniae and Streptococcus pyogenes are two pathogenic bacteria in the genus of Streptococcus.

CONTENTS

1. Overview and Key Difference
2. What is Streptococcus Pneumoniae
3. What is Streptococcus Pyogenes
4. Similarities – Streptococcus Pneumoniae and Streptococcus Pyogenes
5. Streptococcus Pneumoniae vs Streptococcus Pyogenes in Tabular Form
6. Summary – Streptococcus Pneumoniae vs Streptococcus Pyogenes

What is Streptococcus pneumoniae?

Streptococcus pneumoniae is a bacterial species that belong to the genus Streptococcus. It is the causative agent of pneumonia in humans. This bacterium is gram-positive, spherical, and aerotolerant or anaerobic. It is usually found in pairs (diplococci) and does not form spores. Moreover, Streptococcus pneumoniae species are non-motile. This bacterium is the major cause of human pneumonia in the late 19^th century. Therefore, it became the subject of many humoral immunity studies.

Streptococcus pneumoniae normally colonizes in the respiratory tract, sinuses, and nasal cavity. However, in individuals who have weaker immunity, including the elderly, young children, and immunocompromised people, this species may become pathogenic and spread to other locations to cause diseases. It spreads by direct person-to-person contact via respiratory droplets. Sometimes, it causes auto-inoculation in persons carrying the bacteria in the upper respiratory tract.

Streptococcus pneumoniae causes different diseases, including pneumonia, meningitis, sepsis, bronchitis, rhinitis, acute sinusitis, otitis media, conjunctivitis, osteomyelitis, septic arthritis, endocarditis, peritonitis, pericarditis, cellulitis, and abscess in the brain. Furthermore, the virulent factors of this bacterial species include capsule, the cell wall, choline-binding proteins, pneumococcal surface proteins (PspA and PspC), LPXTG anchored neuraminidase proteins, hyaluronate lyase (Hyl), pneumococcal adhesion and virulence A (PavA), enolase (Eno), pneumolysin, and autolysin A.  These infections are normally treated with antibiotics such as cephalosporins and fluoroquinolones (levofloxacin, moxifloxacin). Several vaccines (pneumovax) are also developed to protect against invasive infections caused by S. pneumoniae.

What is Streptococcus pyogenes?

Streptococcus pyogenes is a bacterial species that belongs to the genus Streptococcus that predominantly causes pharyngitis, cellulitis, and erysipelas in humans. It is a species of gram-positive, aerotolerant extracellular bacteria. It is made up of non-motile and non-sporing cocci (round cells) linked in chains. It is a part of the skin microbiota that can cause group A streptococcal infection. Moreover, it harbours the Lancefield group A antigen and is typically categorized as group A Streptococcus (GAS). S, pyogenes cause complete destruction of red blood cells. Hence, this species is beta-hemolytic.

S. pyogenes has several virulent factors, including streptolysin o, streptolysin s, streptococcal pyrogenic exotoxin A (SpeA), streptococcal pyrogenic exotoxin B (SpeB), streptococcal pyrogenic exotoxin C (SpeC), streptokinase, hyluronidase, streptodornase, C5a peptidase, and streptococcal chemokine protease. Examples of S. pyogenes infections include pharyngitis, erysipelas, cellulitis, necrotizing fasciitis, neonatal infections, scarlet fever, toxic shock syndrome, rheumatic fever, and post-infectious glomerulonephritis. Furthermore, the treatments for these infections include antibiotics such as penicillin, vancomycin or clindamycin, and inactivated vaccine (vacuna antipiogena polivalente BIOL).

What are the Similarities Between Streptococcus pneumoniae and Streptococcus pyogenes?

• Streptococcus pneumoniae and Streptococcus pyogenes are two pathogenic bacteria in the genus of Streptococcus.
• Both bacteria are gram-positive, spherical, and aerotolerant anaerobic.
• These bacteria are non-motile and non-spore-forming.
• They are catalase-negative and oxidase negative.
• They are mainly opportunistic pathogens.
• The infections caused by both bacteria are treated by antibiotics and particular vaccines.

What is the Difference Between Streptococcus pneumoniae and Streptococcus pyogenes?

Streptococcus pneumoniae causes pneumonia in humans, while Streptococcus pyogenes predominantly cause pharyngitis, cellulitis, and erysipelas in humans. Thus, this is the key difference between Streptococcus pneumoniae and Streptococcus pyogenes. Furthermore, S. pneumoniae is alpha-hemolytic under aerobic conditions and beta-hemolytic under anaerobic conditions. On the other hand, S. pyogenes is beta-hemolytic in all conditions.

The below infographic presents the differences between Streptococcus pneumoniae and Streptococcus pyogenes in tabular form for side by side comparison.

Summary – Streptococcus pneumoniae vs Streptococcus pyogenes

Streptococcus is a genus of gram-positive, spherical, non-motile, non-spore-forming, catalase-negative and oxidase-negative bacteria. Streptococcus pneumoniae and Streptococcus pyogenes are two pathogenic bacteria in this genus. Streptococcus pneumoniae predominantly causes pneumonia in humans, while Streptococcus pyogenes predominantly causes pharyngitis, cellulitis, and erysipelas in humans. So, this is the key difference between Streptococcus pneumoniae and Streptococcus pyogenes.

Reference:

1. “Streptococcus Pneumoniae: For Clinicians.” Centers for Disease Control and Prevention, Centers for Disease Control and Prevention.
2. “Streptococcus Pyogenes (Group A β-Hemolytic Streptococcus).” Antimicrobe.

Image Courtesy:

1. “Streptococcus pneumoniae – A causative bacteria of meningitis” By www.scientificanimations.com –  (CC BY-SA 4.0) via Commons Wikimedia
2. “Streptococcus pyogenes” By VeeDunn (CC BY 2.0) via Flickr