Difference Between Enterococcus and Streptococcus

Main Difference – Enterococcus vs Streptococcus

Enterococcus and Streptococcus are two bacterial genera, consisting of gram-positive, ovoid and rod-shaped cells respectively. Both types of bacteria are arranged in pairs or chains. Enterococcus tends to form short chains whereas Streptococcus mainly form clusters but, may be single, in pairs or short chains. Both Enterococcus and Streptococcus can be found in the mucous membrane of animals. The main difference between Enterococcus and Streptococcus is that Enterococcus is a common intestinal microbiota while Streptococcus is a common upper respiratory tract microbiota.

Key Areas Covered

1. What is Enterococcus
      – Definition, Structure, Pathology
2. What is Streptococcus
     – Definition, Structure, Pathology
3. What are the Similarities Between Enterococcus and Streptococcus
     – Outline of Common Features
4. What is the Difference Between Enterococcus and Streptococcus
    – Comparison of Key Differences

Key Terms: Common Microbiota, Enterococcus, Gram-Positive Bacteria, Mucous Membranes, Streptococcus

What is Enterococcus

Enterococcus refers to a group of bacteria that naturally occurs in the intestine and causes inflammation and blood infection when introduced elsewhere in the body. It is an ovoid-shaped cell. Enterococci are arranged in short chains. Some Enterococci are motile. Enterococci have complex nutritional requirements. Lactic acid is the main product of the fermentation in Enterococci. Generally, Enterococci are catalase-negative. But, some species produce pseudo-catalase. Catalase is an enzyme required for the detoxification of oxygen gas. Generally, catalase-negative bacteria grow in oxygen-free environments. Many Enterococci species tend to grow at 10 °C. They can also grow at 65 °C in the presence of 6.5% NaCl. Enterococcus infection in pulmonary tissue is shown in figure 1.

Figure 1: Enterococcus sp. in Pulmonary Tissue

The type of peptidoglycans in the cell wall of Enterococcus is lysine-D-asparagine. The cell membrane contains straight chains or mono-unsaturated fatty acids. Some species contain cyclo-propane ring acids.

Pathology

Enterococci cause urinary tract infections, meningitis, bacteremia, bacterial endocarditis, and diverticulitis. They develop resistant to penicillin, ampicillin, and vancomycin. Therefore, new forms of antibiotics are given to inhibit the growth of Enterococci such as quinupristin-dalfopristin, linezolid, daptomycin, tigecycline.

What is Streptococcus

Streptococcus refers to a group of bacteria that causes a multitude of diseases. It is a rod-shaped cell that shows the arrangements of clusters or short chains. Generally, Streptococcus is non-motile. Streptococci are a type of facultative anaerobes that exhibit lactic acid fermentation. Streptococcus is shown in figure 2.

Figure 2: Streptococcus

Pathology

Streptococcus cause hemolytic infections in red blood cells, strep throat, bacterial pneumonia, meningitis, endocarditis, etc. Penicillin is widely-used to treat beta-hemolytic streptococci.

Similarities Between Enterococcus and Streptococcus

• Enterococcus and Streptococcus are two types of Gram-positive bacterial genera.
• Both types of bacteria are arranged in pairs or chains.
• Both Enterococcus and Streptococcus can be found in the mucous membrane of animals as commensals.
• Some Enterococcus and Streptococcus are found in soil.
• The long-chain fatty acids in the cell membrane of both Enterococcus and Streptococcus are straight-chains or mono-unsaturated types.
• Both Enterococcus and Streptococcus are non-sporing, facultative anaerobes.
• Both Enterococcus and Streptococcus undergo lactic acid fermentation.
• Both Enterococcus and Streptococcus are catalase-negative.
• Both Enterococcus and Streptococcus are human pathogens that cause diseases.

Difference Between Enterococcus and Streptococcus

Definition

Enterococcus: Enterococcus refers to a group of bacteria that naturally occurs in the intestine and causes inflammation and blood infection when introduced elsewhere in the body.

Streptococcus: Streptococcus refers to a group of bacteria that produce agents of souring of milk, dental decay, and hemolytic infections.

Shape

Enterococcus: Enterococcus is ovoid shaped.

Streptococcus: Streptococcus is rod-shaped.

Arrangement

Enterococcus: Enterococcus tends to form short chains.

Streptococcus: Streptococcus mainly form clusters but, may be single, in pairs or short chains.

Pyrrolidonylarylamidase

Enterococcus: Most species of Enterococci produce pyrrolidonylarylamidase.

Streptococcus: Pyrrolidonylarylamidase is not produced by Streptococci.

G+C Content

Enterococcus: The G+C content of Enterococci is ~ 38-45%.

Streptococcus: The G+C content of Streptococci is ~33-46%.

Motility

Enterococcus: Some species of Enterococci are motile.

Streptococcus: Streptococci are non-motile.

Type of Mucous Membranes

Enterococcus: Enterococcus is common intestinal microbiota.

Streptococcus: Streptococcus is common upper respiratory tract microbiota.

Hemolysis

Enterococcus: Enterococcus does not cause hemolytic infections.

Streptococcus: Streptococcus cause hemolytic infections.

Pathology

Enterococcus: Enterococcus causes inflammation and blood infection when introduced elsewhere in the body.

Streptococcus: Streptococcus causes hemolytic infections.

Resistance to Penicillin

Enterococcus: Enterococcus develop resistance to penicillin.

Streptococcus: Streptococcus is not resistant to penicillin.

Conclusion

Enterococcus and Streptococcus are two genera of gram-positive bacteria. Both types of bacteria found in mucous membranes of animals as natural microbiota. Enterococcus is found in the upper respiratory tract whereas Streptococcus is found in the intestinal tract. The main difference between Enterococcus and Streptococcus is the type of mucous membranes each bacterial genera.

Reference:

1. Hardie, J.M., and R.A. Whiley. “Classification and overview of the genera Streptococcus and Enterococcus.” Journal of Applied Microbiology, Blackwell Science Ltd, 30 Oct. 2003, Available here.
2. “Enterococcal Infections.” Background, Pathophysiology, Epidemiology, 2 Jan. 2018, Available here.
3. “Streptococcus species.” Pathology Outlines – PathologyOutlines.Com, Available here.

Image Courtesy:

1. “Enterococcus histological pneumonia 01” By Photo Credit:Content Providers(s): CDC/Dr. Mike Miller – Cropped from This media comes from the Centers for Disease Control and Prevention’s Public Health Image Library (PHIL) (Public Domain) via Commons Wikimedia
2. “Streptococcus mutans 01” By PStreptococcus mutansTranswiki approved by: w:en:User:Dmcdevit – This media comes from the Centers for Disease Control and Prevention’s Public Health Image Library (PHIL) (Public Domain) via Commons Wikimedia