Question

1. Once inside your body, MRSA will cause some very specific reactions to take place, recruiting specialized cells to attach the MRSA. Describe what cells are being recruited and what is happening in this stage of immunity. Be sure to explain the origin of the cells and what types of things they produce.

Answer 1

Answer- MRSA is Methicillin- resistant Staphylococcus aureus, it is a bacteria which causes infection in different parts of body.

Symptoms of body in MRSA:

In MRSA symptoms depends on where the person is affected , it usually appears as skin infection, boil or abscess.

The affected area looks swollen, red, painful, abscessful if it is filled with liquid.

If it affects the lungs and causes pneumonia, shortness of breath, fever, cough and chills occur.

Once MRSA enters the body, it can remain in any part and cause abscess in the spleen, kidney, spine, etc. It can also cause endocarditis (heart valve infection), osteomyelitis (bone infection), joint infection, breast mastitis and prosthetic device infection.

MSRA is attached to the surface proteins required for binding throughout the body. These surface proteins help to attach laminin and fibronectin. In many strains, a clumping factor is also found called coagulase, which promotes its attachment to the blood clots and traumatized tissue. Once the bacteria are attached, it secretes a biofilm that makes it difficult to kill or control the bacteria. Invasin helps to promote spread of bacteria within the tissues of the body.

The CA-MRSA strain produces a type of peptide which is produced by the amino acids, it bursts the neutrophils, as a result it escapes body's defence mechanism and causes disease.

Staph frequently causes skin infections but occasionally can lead to deadly conditions such as sepsis, pneumonia and bloodstream infections, particularly in hospitalized patients whose immune systems could be weakened by illness.

One strain of the bacterium, the superbug methicillin-resistant Staphylococcus aureus (MRSA), is considered one of the top drug-resistant threats

Neutrophil recruitment, chemotaxis, and priming:

A first step in the eradication of invading microorganisms is active recruitment of PMNs to the site of infection by chemotaxis. This is a multistep process whereby neutrophils are mobilized from peripheral blood and/or bone marrow in response to host- and pathogen-derived chemotactic factors. Host molecules, such as interleukin-8 (IL-8, CXCL8), GROα (CXCL1), granulocyte chemotactic protein 2 (GCP2, CXCL6), and complement component C5a, recruit neutrophils to the site of infection.

Neutrophils, a type of white blood cell that ensnares invaders in neutrophil extracellular traps (NETs), a web-like structure of DNA and proteins, is one of the first lines of defense in the human immune response. Captured bacteria are then destroyed by amoeba-like white blood cells known as macrophages. However, S. aureus infection sites are often marked by an absence of macrophages, indicating the bacteria somehow defend themselves against the immune system.

The innate immune response is the leading defense against MRSA infections. Neutrophils are recruited to the site of infection by Pathogen Recognition Receptors binding to the bacteria, causing them to release interleukin-8 (IL-8, CXCL8), GROα (CXCL1), granulocyte chemotactic protein 2 (GCP2, CXCL6), and complement component C5a. These chemokines help to recruit neutrophils to the site of infection in order to assist macrophages in phagocytosis of the bacteria. The triggering of the innate immune response and neutrophil recruitment also serve to trigger complement activation and inflammation, which contribute to the destruction of the pathogens.