Streptococcus Pneumoniae and Streptococcus Pyogenes

Difference Between Streptococcus Pneumoniae and Streptococcus Pyogenes

Streptococcus Pneumoniae

Streptococcus pneumoniae (also referred to as pneumococcus) is a Gram-positive bacteria commonly found colonizing human upper respiratory tracts and contributing to numerous infections affecting these passageways, especially respiratory tract infections.

Streptococcus Pneumoniae
Figure-No-01: Streptococcus Pneumoniae

Here is some key information and characteristics about Streptococcus pneumoniae:

  • Morphology: Streptococcus pneumoniae appears as lancet-shaped or elongated cocci when examined under a microscope, often in pairs or chains.
  • Gram Staining: Streptococcus pneumoniae is classified as a Gram-positive bacteria due to a thick peptidoglycan layer in its cell wall that retains a purple hue in the Gram staining procedure.
  • Virulence Factors of Streptococcus pneumoniae: One major virulence factor of Streptococcus pneumoniae is its polysaccharide capsule, which protects it from being attacked by immune system cells. Pneumolysin produced by this bacterium also plays a significant role, damaging host cells, and further intensifying infections.
  • Clinical Presentation: Streptococcus pneumoniae is one of the major sources of respiratory tract infections such as pneumonia, sinusitis, and otitis media. Furthermore, it may lead to more invasive forms such as meningitis, bacteremia (bloodstream infection), or sepsis with different strains being more likely associated with more serious infection rates than others.
  • Epidemiology: Streptococcus pneumoniae infections are frequently found among young children, older adults, and those with compromised immunity systems. Its infections contribute substantially to morbidity and mortality worldwide – particularly in developing countries – often via respiratory droplets from infected individuals.
  • Diagnosis: Streptococcus pneumoniae infections can be identified and isolated through clinical samples such as sputum, blood, or cerebrospinal fluid using culture techniques, microscopy methods, or molecular approaches for diagnosis.
  • Treatment and Prevention: Antibiotics are typically recommended as treatments for Streptococcus pneumoniae infections, depending upon resistance patterns of particular antibiotics. Pneumococcal vaccination should also be considered an important preventative strategy – specifically infants, older adults and individuals living with certain medical conditions should receive pneumococcal vaccination to guard against potential infection.
  • Antibiotic Resistance: Streptococcus pneumoniae has recently emerged as an increasing source of concern due to an escalating rise in drug-resistant strains. Some strains have even developed resistance against multiple antibiotics, severely restricting treatment options while highlighting the importance of responsible use.

Streptococcus pneumoniae is an important human pathogen responsible for respiratory and invasive infections in both people. Understanding its characteristics, virulence factors and epidemiology is crucial to diagnose, treat, and prevent pneumococcal diseases.


In 1881 the bacteria that was identified later, in 1886 as pneumococcus because of its potential in the development of pneumonia, was discovered in tandem and independently by U.S. Army physician George Sternberg along with the French chemical scientist Louis Pasteur.

The species was named Diplococcus pneumoniae as early as 1920 due to its distinctive appearance in Gram-staining sputum. It was named Streptococcus pneumophile in 1974 because it looked quite identical to streptococci.

Streptococcus pneumoniae played a major part in the demonstration that genetic material is made up of DNA. The year 1928 was when Frederick Griffith demonstrated the transformation of the harmless pneumococcus into a lethal version by introducing living pneumococci to mice, along with the heat that killed the virulent pneumococci. Then, in 1944, Oswald Avery, Colin MacLeod as well as Maclyn McCarty proved that the key factor responsible for transformation in Griffith’s research wasn’t protein as was commonly believed in the early days however, it was DNA. The work of Avery marked the beginning of the molecular age of genetics.


The diagnosis is usually from clinical suspicion a positive culture of samples taken from almost every body part. S. pneumoniae is generally optochin-sensitive, however optochin resistance has been reported.

Recent advances in next-generation sequencing as well as comparative genomics has enabled the development of strong and reliable molecular strategies to identify and detect of S. pneumoniae. In particular, the Xisco gene has been recently identified as a biomarker used in PCR-based screening of S. pneumoniae, as well as for separation from closely similar species.

Atromentin and leucomelone both have antibacterial properties, preventing the enzyme enoyl acyl carrier protein reductase (essential in the biosynthesis of fat acids) in S. pneumoniae.

Streptococcus Pyogenes

Streptococcus pyogenes (AKA Group A Streptococcus or GAS), commonly found colonizing human throat and skin tissues. As one of the main culprits responsible for an array of infectious conditions it poses numerous threats and threat posed by Streptococcus pyogenes infections are numerous and serious.

Streptococcus Pyogenes
Figure-No-02: Streptococcus Pyogenes

Here is some key features and information regarding Streptococcus pyogenes:

  • Morphology: Streptococcus pyogenes can be identified through visual inspection as chains of spherical cocci. Gram staining results in its cells remaining purple-stain stained; each strain exhibits different characteristics when examined under a microscope.
  • Virulence Factors: Streptococcus pyogenes is known to produce several virulence factors that contribute to its pathogenicity. M protein plays an essential role in adhesion and immune evasion while streptolysins O and S produce by this bacteria can damage tissues causing tissue necrosis; streptokinase enzyme produced by S. pyogenes acts to spread its bacteria throughout host tissues more quickly.
  • Clinical Presentation: Streptococcus pyogenes can lead to various infections. Most commonly associated with streptococcal pharyngitis (strep throat), it typically presents with sore throat, fever and swollen tonsils; also commonly linked with impetigo (superficial skin infection) and cellulitis (deep skin infection), it has even been known to cause necrotizing fasciitis – an increasingly worsening and life-threatening condition) and toxic shock syndrome in severe cases.
  • Epidemiology: Streptococcus pyogenes infections are most frequently seen among school-age children and adolescents, particularly school aged children who attend daycare centers, schools or daycare facilities where it’s likely that these infectious agents could spread via respiratory droplets or direct contact between infected individuals and susceptible hosts (which makes the spread easy).
  • Diagnosis: Diagnosing Streptococcus pyogenes infections usually involves isolating and identifying it from clinical samples like throat swabs or skin lesions, usually through rapid antigen detection tests and culture methods.
  • Treatment and Prevention: Antibiotics such as penicillin or amoxicillin are the go-to treatments for Streptococcus pyogenes infections, with prompt medical intervention being key in avoiding complications and protecting oneself against further risk. Proper hand hygiene practices, avoiding close contact with infected individuals and covering coughs or sneezes as prevention are among the strategies available in order to stay protected against complications caused by Streptococcus pyogenes infections are effective preventive strategies; currently there is no widely available vaccine against Streptococcus pyogenes infections available commercially.
  • Complications: Streptococcus pyogenes infections can result in post-infection complications, including acute rheumatic fever (an autoimmune response that damages heart, joints and other organs) and post-streptococcal glomerulonephritis (an inflammation of kidney). These may develop following streptococcal pharyngitis or skin infections.

Understanding the characteristics, virulence factors and clinical manifestations of Streptococcus pyogenes is crucial for accurate diagnosis, effective treatment and the prevention of streptococcal infections and complications that arise as a result.


S. Pyogenes usually colonizes the throat, the genital mucosa and rectum as well as the skin.¬†In healthy people between 1% and five percent suffer from vaginal, throat, or rectal carriage.¬†Children who are healthy, this frequency of carriage varies between 2 to 17 percent.¬†There are four ways to trigger the transmission of this bacterium. They are the inhalation of respiratory droplets contact through skin with surfaces, objects or dust that’s infected with the bacteria, or more rarely, through food.

The bacteria that cause it can trigger a range of illnesses, including streptococcal-related pharyngitis and rheumatic and rheumatic heart diseases, and even scarlet fever. While pharyngitis tends to be due to viral causes, approximately 15 % to 30 percent of all cases among children result from GAS while five to 20 percent of cases of pharyngitis among adults are caused by streptococcal.

Pharyngitis incidence is greater among children than those of adults because of exposure to nurseries and schools as well due to the lower immunity of host. The incidences of Streptococcal Pharyngitis are more frequent during the latter part of winter and early spring in the countries with seasonal climates because of the large number of people breathing similar air in the indoors. Cases of disease are at their least during the fall.

It is believed that the MT1 (metabolic type 1) Clone is often linked to an invasive Streptococcus Pyogenes infection in the advanced countries. The prevalence and death rate of S. Pyogenes were excessive prior to penicillin however, it had begun to decrease prior to the widely available penicillin. So, the environment can contribute to the S. Pyogenes infections. The incidence of S. Pyogenes ranges from about 2-4 per 100,000 people in the developed world as well as 12 to 83 percent of 100,000 people in the developing world. S.

Pyogenes is most often seen in males than women, and has the highest prevalence in elderly people as well as babies. People who have risk factors, such as heart disease, diabetes cancer, blunt trauma surgery, viral respiratory infections, such as the flu S. Pyogenes infections is found in between 17 and 25 percent of the instances. GAS secondary infections usually occur within a week after being diagnosed with influenza. For 14 to 16 percent of all childhood S.

Pyogenes infections there has been a prior chickenpox-related disease. The type of S. Pyogenes disease is usually seen in children as a serious soft tissue inflammation that develops between 4 and 12 days after the diagnosis of chickenpox. Also, there is a an increase of 40-60 times in risk for S. Pyogenes-related infections in the first 2 weeks following chickenpox in infants. But, between 20 and 30 percent of S. Pyogenes-related infections occur in adults who have no known factors that could be considered risky. This is especially true for youngsters (50 to 80 percent of S. Pyogenes infections) without any known risks.

The scarlet fever rate in the UK were typically 4 per 100,000 inhabitants, however, in 2014, rate had increased up to 49 for every 100,000. Rheumatic fever and heart disease (RHD) typically occur about 2 or 3 weeks after an infection in the throat, which occurs more frequently among poor in the developing world. Between 1967 and 1996 the mean global incidence of rheumatic illness as well as RHD was 19/100,000 and the highest rate was 51/100,000.

Maternal S. Pyogenes infections typically occurs in the latter stages of pregnancy when the mother is greater than 30 weeks gestation up to 4 weeks postpartum that accounts for 2 to 4 percent of the S. Pyogenes-related infection.¬†This is 20 to 100 times more risk for S. Pyogenes infections.¬†The clinical manifestations include pneumonia, septic arthritis necrotizing fasciitis and sepsis of the genital tract.¬†Based on a research conducted by the Queen Charlotte’s Hospital in London in the 1930s vagina was not a typical source for this type of disease.¬†In fact, it was the mother’s throat infections as well as close contact with carriers were among the most typical sites for mother S. Pyogenes infections.


S. Pyogenes is a reason for a variety of human illnesses that range from minor superficial skin conditions to serious systemic illnesses. 2] Most infections start with the throat or on the on the skin. Most noticeable is a rash that resembles a strawberry. Some examples of mild S. Pyogenes infection include Pharyngitis (strep throat) as well as localized skin infections (impetigo). Erysipelas and cellulitis are characterised by the spread of S. Pyogenes within the deep skin layers. S. Pyogenes infection and multiplication of the fascia may result in necrotizing fasciitis the most serious form of cancer that demands immediate surgical intervention to minimize the chance of dying and morbidity. The bacterium can be present in newborn infection.

The infection caused by specific types of S. Pyogenes are due to the release of toxins produced by bacteria. Infections of the lungs that are associated with the release of specific toxins can cause scarlet fever. Other toxic S. Pyogenes infections could cause streptococcal toxic shock syndrome that can be life-threatening.

S. Pyogenes be the cause of illness by causing post-infectious “non-pyogenic” (not associated with local bacterial multiplication, or pus development) syndromes.¬†The autoimmune-related complications are the majority of infections, and can comprise rheumatic fever as well as acute glomerulonephritis post-infectious.¬†Both of these conditions develop after the first streptococcal infection.¬†Rheumatic fever manifests as joint inflammation and/or the heart after an episode of streptococcal-induced Pharyngitis.¬†An acute glomerulonephritis, which is inflammation of the glomerulus in the kidney, could be the result of streptococcal-related pharyngitis and an infection of the skin.

The bacterium continues to be highly vulnerable to penicillin. The failure of penicillin treatment is usually attributed to local organisms that make B-lactamase or failing to attain adequate levels of tissues within the Pharynx. Certain strains are resistant to macrolides and tetracyclines and clindamycin.

Difference Between Streptococcus Pneumoniae and Streptococcus Pyogenes

Streptococcus pneumoniae and Streptococcus pyogenes both belong to the Streptococcus genus. each has special features which distinguish it from one another.

Below are a few key differences between Streptococcus pneumoniae and Streptococcus pyogenes:

  • Morphology: Streptococcus pneumoniae typically manifests itself in lancet-shaped or elongated cocci; on the other hand, Streptococcus pyogenes is characterized by chains of spherical cocci.
  • Gram Staining: Streptococcus pneumoniae and Streptococcus pyogenes both test gram-positive for Gram staining; therefore they retain a purple stain during this procedure.
  • Virulence Factors: Streptococcus pneumoniae is well known for producing its capsule, which allows it to bypass immune defense systems and produce pneumolysin, a cytotoxin that damages host cells. Streptococcus pyogenes produces M protein for adhesion and immune evasion as well as streptolysins which contribute to tissue damage as well as streptokinase which facilitates its spread through human tissues.
  • Clinical Manifestations: Streptococcus pneumoniae often results in respiratory infections such as pneumonia, sinusitis, otitis media, and meningitis; more serious consequences include meningitis and bacteremia. Streptococcus pyogenes can cause streptococcal pharyngitis (strep throat), skin infections such as impetigo and cellulitis, and more severe conditions like necrotizing fasciitis or toxic shock syndrome.
  • Epidemiology: Streptococcus pneumoniae is one of the main causes of pneumonia worldwide, particularly among young children and older adults, leading to high morbidity and mortality rates. Streptococcus pyogenes is frequently responsible for bacterial pharyngitis or skin infections in school-age children and adolescents.
  • Prevention: Pneumococcal vaccines provide protection from Streptococcus pneumoniae infections; however, no widespread vaccination for Streptococcus pyogenes is yet available.
  • Complications: Streptococcus pneumoniae infections may lead to complications including pleural effusions, empyemas, and sepsis; while infections with Streptococcus pyogenes can result in post-streptococcal complications including rheumatic fever or post-streptococcal glomerulonephritis.

Note that although these are general differences between these bacteria, there can be overlap and variations in their clinical presentations and characteristics; proper laboratory diagnosis will help distinguish them and guide appropriate treatment plans.

Similarities Between Streptococcus Pneumoniae and Streptococcus Pyogenes

Streptococcus pneumoniae and Streptococcus pyogenes have distinct characteristics; however, they share certain similarities as well.

Examples are:

  • Gram-positive bacteria: Streptococcus pneumoniae and Streptococcus pyogenes both fit the classification of Gram-positive bacteria, meaning they retain crystal violet dye for staining using Gram staining method, producing purple colors upon analysis by this staining method.
  • Coccal Morphology: Both bacteria have coccal shapes. Streptococcus pneumoniae typically forms pairs or short chains while Streptococcus pyogenes forms long chains and pairs.
  • Fungi that grow as facultative anaerobes: Both bacteria are facultative anaerobes, meaning that they can survive and multiply with or without oxygen present.
  • Human Pathogens: Both Streptococcus pneumoniae and Streptococcus pyogenes can be detrimental to humans by inflicting various infections upon us, most frequently targeting our respiratory system but potentially leading to other more invasive illnesses as well. They typically colonize in our upper respiratory tract area where they cause infection as well as potentially incurring more invasive illnesses in rare instances.
  • Group A Streptococcus: Streptococcus pyogenes is part of Lancefield Group A Streptococci (GAS), while Streptococcus pneumoniae does not belong to any Lancefield groups based on carbs on its cell wall. This classification system takes account of this feature when classifying bacteria.

At Streptococcus pneumoniae and Streptococcus pyogenes, there are similarities, yet distinct distinctions in their virulence factors, clinical manifestations, epidemiology, and epidemiological trends. Understanding both of these is vital in accurately diagnosing, treating, and preventing infections caused by Streptococcus pneumoniae or Streptococcus pyogenes.


Streptococcus pneumoniae and Streptococcus pyogenes are both distinct bacterial pathogens with unique features and clinical implications, with Streptococcus pneumoniae often being responsible for respiratory tract infections such as pneumonia. Meanwhile, Streptococcus pyogenes can often lead to throat, skin, or nail infections in its wake.

Streptococcus pneumoniae is easily identifiable by its encapsulated shape and alpha-hemolytic colonies on blood agar media, along with possessing several virulence factors including polysaccharide capsules and pneumolysin which contribute to its pathogenicity – it may lead to pneumonia, sinusitis, otitis media, meningitis or bloodstream infections in humans and can even infect livestock and farm animals.