Difference Between Streptococcus and Staphylococcus

Main Difference – Streptococcus vs Staphylococcus

Streptococcus and Staphylococcus are two bacterial genera with a similar spherical shape. Both Streptococcus and Staphylococcus are gram positive bacteria. Though both bacterial genera have the same cell shape, they possess different arrangements based on the different styles of binary fission. Streptococci forms a chain of bacterial cells due to the binary fission that occurs in one linear direction while Staphylococci forms a grape-like structure due to the binary fission that occurs in various directions. The main difference between Streptococcus and Staphylococcus is that Streptococcus is mainly a facultative anaerobe whereas Staphylococcus is mainly an aerobe.

Key Areas Covered

1. What is Streptococcus
     – Definition, Characteristics, Clinical significance
2. What is Staphylococcus
     – Definition, Characteristics, Clinical significance
3. What are the Similarities Between Streptococcus and Staphylococcus
     – Outline of Common Features
4. What is the Difference Between Streptococcus and Staphylococcus
     – Comparison of Key Differences

Key Terms: Binary Fission, Catalase, Gram Positive Bacteria, Infection, Staphylococcus, Streptococcus

What is Streptococcus

Streptococcus refers to a gram positive bacterial genus that remains attached to growing bead-like chains. Many Streptococcal species are non-pathogenic. They are catalase-negative. Catalase is the enzyme used by bacteria to convert hydrogen peroxide into oxygen and water. Most Streptococci are facultative anaerobes. Some are obligate anaerobes. Streptococci require an enriched medium such as blood agar for their growth. They are commonly found in the throat. Streptococci are shown in figure 1.

Figure 1: Streptococcus mutans

Under some conditions, Streptococci may cause diseases such as reduced immunity.  Streptococcus pneumoniae causes pneumonia, meningitis, and occult bacteremia. Streptococcus pyogenes causes rheumatic fever, an inflammatory disease affecting the heart, brain, joints, and the skin. This bacterial species also causes tonsillitis, strep throat, puerperal fever, scarlet fever, streptococcal toxic shock syndrome, and impetigo (a skin infection). The symptoms of a Streptococcal infection can be fever, swollen lymph nodes, sore throat, rash, red and weeping skin sores, confusion, and dizziness.

What is Staphylococcus

Staphylococcus refers to a gram positive bacterial genus that produces a bunch of grape-like bacterial clusters. It is mainly found on the skin and mucous membranes of healthy individuals as natural microbiota. Generally, Staphylococci except Staphylococcus aureus are catalase-positive Most Staphylococci are aerobes while some such as Staphylococcus aureus are facultative anaerobes. Staphylococcus aureus is shown in figure 2.

Figure 2: Staphylococcus aureus

Under some circumstances such as a wound, Staphylococci may cause infections. The types of infections can be either pneumonia, toxic shock syndrome, blood infections (bacteremia), bone infections (osteomyelitis), infections of the inner lining of the heart and its valves (endocarditis) or abscesses in internal organs. The symptoms of the Staphylococcal infections can be fever, chills, low blood pressure, and red, swollen, tender pimple-like bumps.

Similarities Between Streptococcus and Staphylococcus

• Streptococcus and Staphylococcus are two bacterial genera.
• Both Streptococcus and Staphylococcus are spherical shaped bacteria.
• Both Streptococcus and Staphylococcus are gram positive
• Both Streptococcus and Staphylococcus consist of facultative anaerobes.
• Both Streptococcus and Staphylococcus are non-motile bacteria.
• Both Streptococcus and Staphylococcus undergo binary fission as their asexual reproduction method.
• Both Streptococcus and Staphylococcus do not produce spores.
• Both Streptococcus and Staphylococcus are common members of normal human microbiota.
• Both Streptococcus and Staphylococcus are capable of resisting many forms of antibiotics.
• Both Streptococcus and Staphylococcus produce virulent factors such as toxins.
• Both Streptococcus and Staphylococcus can be pathogenic to humans, causing serious infections or even death.

Difference Between Streptococcus and Staphylococcus

Definition

Streptococcus: Streptococcus refers to a gram positive bacterial genus that remains attached to growing bead-like chains.

Staphylococcus: Staphylococcus refers to a gram positive bacterial genus that produces a bunch of grape-like bacterial clusters.

Binary Fission 

Streptococcus: The binary fission of Streptococcus occurs in one linear direction (single axis).

Staphylococcus: The binary fission of Staphylococcus occurs in various directions (multiple axes).

Number of Species

Streptococcus: There are about 50 Streptococcal species identified so far.

Staphylococcus: There are about 40 Staphylococcal species identified so far.

Type of Respiration

Streptococcus: Most Streptococci are facultative anaerobes while some are obligate anaerobes.

Staphylococcus: Most Staphylococci are aerobes while some are facultative anaerobes.

Catalase Test

Streptococcus: Streptococcus give negative results for the catalase test as it does not produce catalase enzyme in the cell.

Staphylococcus: Staphylococcus give positive results for the catalase test as it produces the catalase enzyme.

Habitat

Streptococcus: Streptococci can be found in the respiratory tract.

Staphylococcus: Staphylococci can be found on the skin.

Type of Arrangement

Streptococcus: Streptococci form a chain of bacteria.

Staphylococcus: Staphylococci form a bunch of grapes-like structure.

Enriched Media

Streptococcus: Streptococci require an enriched media for growth as they are fastidious.

Staphylococcus: Staphylococci do not require an enriched media for growth as they are not fastidious.

Type of Hemolysis

Streptococcus: Streptococci exhibit alpha, beta or gamma hemolysis.

Staphylococcus: Staphylococci exhibit no hemolysis, but sometimes exhibit beta hemolysis.

Pathogenesis

Streptococcus: Streptococci cause many diseases.

Staphylococcus: Staphylococci is generally non-pathogenic.

Common Diseases

Streptococcus: Strep throat, toxic shock syndrome, and Scarlet fever are some of the common disease caused by Streptococci.

Staphylococcus: Food poisoning, skin diseases, bacterial conjunctivitis are some of the common diseases caused by Staphylococci.

Most Pathogenic Species

Streptococcus: Streptococcus pneumoniae, Streptococcus pyogens, and Streptococcus agalactiae are the most pathogenic species of Streptococci.

Staphylococcus: Staphylococcus aureus and Staphylococcus saprophyticus (in female) are the most pathogenic species of Staphylococci.

Types of Symptoms

Streptococcus: The symptoms of a Streptococcal infection can include fever, swollen lymph nodes, sore throat, rash, red and weeping skin sores, confusion, and dizziness.

Staphylococcus: The symptoms of the Staphylococcal infections can include fever, chills, low blood pressure and red, swollen, tender pimple-like bumps.

Useful Diagnostic Tests

Streptococcus: Catalase Test, bile solubility test (S. pneumoniae), bacitracin sensitivity test (S. pyogens), CAMPT test (S. agalactiae), and optochin sensitivity test (S. pneumoniae) are the useful tests in the diagnostics of Streptococci.

Staphylococcus: Catalase Test, novobiocin sensitivity test, and coagulase test are the useful tests in the diagnostics of Staphylococci.

Treatment

Streptococcus: Penicillin is used to treat Streptococcal infections.

Staphylococcus: Vancomycin is used to treat Staphylococcal infections.

Conclusion

Streptococcus and Staphylococcus are two bacterial genera with gram positive bacteria. Both Streptococcus and Staphylococcus are spherical shaped bacteria. Streptococci are mainly aerobes while Staphylococcus are mainly facultative anaerobes. The main difference between Streptococci and Staphylococcus is their respiration.

Reference:

1. Patterson, Maria Jevitz. “Streptococcus.” Medical Microbiology. 4th edition., U.S. National Library of Medicine, 1 Jan. 1996, Available here.
2. Foster, Timothy. “Staphylococcus.” Medical Microbiology. 4th edition., U.S. National Library of Medicine, 1 Jan. 1996, Available here.

Image Courtesy:

1. “Streptococcus mutans Gram” By Y tambe – Y tambe’s file (CC BY-SA 3.0) via Commons Wikimedia
2. “Staphylococcus aureus Gram” By Y Tambe (CC BY-SA 3.0) via Commons Wikimedia