What is the Difference Between Coagulase Negative and Positive Staphylococcus

The main difference between coagulase-negative and positive Staphylococcus is that coagulase-negative Staphylococcus does not contain coagulase enzyme, while coagulase-positive Staphylococcus contains coagulase enzyme.

Coagulase-negative and positive Staphylococcus are two groups of Staphylococcus. Staphylococcus is a Gram-positive bacterium that forms clumps. 

Key Areas Covered

1. What is Coagulase Negative Staphylococcus
– Definition, Features, Importance
2. What is Coagulase Positive Staphylococcus
– Definition, Features, Importance
3. Similarities Between Coagulase Negative and Positive Staphylococcus
– Outline of Common Features
4. Difference Between Coagulase Negative and Positive Staphylococcus
– Comparison of Key Differences

Key Terms 

Coagulase Negative Staphylococcus, Coagulase Positive Staphylococcus

What is Coagulase Negative Staphylococcus

Coagulase-negative Staphylococcus is a Gram-positive, aerobic organism that colonizes the human skin. Over 47 species of coagulase-negative staphylococci are identified. Notably, they lack an enzyme called coagulase that promotes thrombus formation by converting fibrinogen into fibrin. Due to the lack of coagulase enzyme, they are non-pathogenic and live on the human skin as commensals. Therefore, they are an important part of the normal skin microbiota. Also, they colonize the mucus membranes. In addition, they prefer humid areas such as the axillae, gluteal, and inguinal regions, as well as anterior nares and the conjunctiva.

Figure 1: S. Epidermidis

For example, S. epidermidis prefers colonizing in the axillae, groin, perineum, toe webs, anterior nares, and conjunctiva. Also, S. haemolyticus and S. hominis colonize in the axillae and pubic areas high in apocrine glands. Additionally, S. capitis colonizes the sebaceous glands on the forehead and scalp following puberty. Furthermore, S. lugdunensis colonizes the axillae, pelvis, and perineum regions, groin, and lower extremities. However, they tend to form biofilms in clinical specimens and become leading pathogens for nosocomial infections. 

What is Coagulase Positive Staphylococcus

Coagulase-positive Staphylococcus is a group of Staphylococcus that produce the enzyme coagulase. It is responsible for the conversion of fibrinogen into fibrin. S aureus and S intermedius are the two species of Staphylococcus that are coagulase-positive. S. aureus live in the axillae and nasal passage. It expresses many virulence factors. They include the surface proteins that promote the colonization in the host, factors that prevent the phagocytosis such as capsules, immunoglobulin binding protein A, host issue damaging toxins, disease-causing toxins, etc. Therefore, coagulase-positive Staphylococcus is more virulent than coagulase-negative Staphylococcus, which does not produce virulent factors.

Figure 2: Coagulase Test

Moreover, coagulase-positive Staphylococci are pathogenic. Penicillinase-resistant β-lactams are the treatment for infections outside the hospitals. In contrast, the hospital-acquired infections are treated with vancomycin. Also, multiple antibiotic resistance is common in coagulase-positive Staphylococci, and methicillin-resistant S. aureus (MRSA) causes outbreaks in hospitals. 

Similarities Between Coagulase Negative and Positive Staphylococcus

• Coagulase-negative and positive Staphylococcus are two groups of Staphylococcus that are Gram-negative bacteria of 1μm diameter.
• They form clumps. 

Difference Between Coagulase Negative and Positive Staphylococcus

Definition

Coagulase-negative Staphylococcus refers to gram-positive, aerobic organisms distinguished from the closely related Staphylococcus aureus by the group’s inability to form coagulase, an enzyme that promotes thrombus formation via the conversion of fibrinogen into fibrin. At the same time, coagulase-positive Staphylococcus refers to opportunistic pathogens carrying various resistance mechanisms that have many virulence factors and whose ability to induce illness is associated with the host.

Significance

Coagulase-negative Staphylococcus does not contain coagulase enzyme, while coagulase-positive Staphylococcus contains coagulase enzyme.

Types

Over 47 other species of coagulase-negative Staphylococci, while coagulase-positive Staphylococcus includes S aureus and S intermedius.

Function

Coagulase-negative Staphylococcus is a common commensal of the skin, while coagulase-positive Staphylococcus constitutes the most pathogenic species.  

Virulence Factors

Coagulase-negative Staphylococcus does not produce virulence factors, while coagulase-positive Staphylococcus produces virulence factors. 

Conclusion

In brief, coagulase-negative and positive Staphylococcus are two groups of Staphylococcus species characterized by coagulase enzyme. Importantly, coagulase-negative Staphylococcus does not contain the coagulase enzyme. Over 47 species of coagulase-negative Staphylococci occur in nature. They are common commensals of the skin. In contrast, coagulase-positive Staphylococcus contains the coagulase enzyme. Only S aureus and S intermedius are coagulase-positive. However, they are the most pathogenic species of Staphylococcus. Therefore, the main difference between coagulase-negative and coagulase-positive Staphylococcus is the presence of coagulase enzyme. 

References:

1. Coagulase Negative Staphylococci. DermNet. (n.d.-a). 
2. Foster T. Staphylococcus. In: Baron S, editor. Medical Microbiology. 4th edition. Galveston (TX): University of Texas Medical Branch at Galveston; 1996. Chapter 12.

Image Courtesy:

1. “Staphylococcus epidermidis” By Dr. Sahay – Own work (CC-BY SA 3.0) via Commons Wikimedia
2. “Tube coagulase test of Staphylococcus aureus -Positive and negative Demonstration ” By Ajay Kumar Chaurasiya – Own Work (CC-BY SA 4.0) via Commons Wikimedia