Virulence Facto of micropilogy of bactiria.pptx

Micro

1. Virulence Factors and Pathogenesis The pathogenesis depends on two important virulence factors: 1- Capsule : ( poly d-glutamic acid) is an essential virulent factor that helps the bacterial pathogen to escape host immunity (inhibiting phagocytosis).

- inhibit complement-mediated clearance and ensure bacterial survival in the host.

- Capsule is plasmid (pX02) coded.

- loss of plasmid which control capsule production leads to loss of virulence .

2. Virulence Factors and Pathogenesis 1. Protective antigen - Binding fragment → Binds to the host cell receptors and facilitates the entry of other fragments into the host cells. 2. Edema factor - Active fragment → Acts as adenylyl cyclase →increases host cell cAMP in host → Edema 3. L ethal factor - Causes cell death → Acts by cleaving host cell MAPK (mitogen-activated protein kinases). 2 - Anthrax Toxin : Three component protein exotoxin :

3. Clinical Manifestations Anthrax is : a serious infectious disease caused by gram-positive, rod-shaped bacteria " Bacillus anthracis". Clinical Types : 1. Cutaneous anthrax. 2. Inhalation (Pulmonary) anthrax . 3. GIT (Intestinal) anthrax .

4. Cutaneous anthrax Infection usually develops from 1 to 7 days When spores get into the skin, through a cut. common form of anthrax infection, and least dangerous. most common on the head, neck, forearms, and hands. Symptoms: - A group of small blisters or bumps that may itch. - Swelling occur around the sore. - A painless skin sore (ulcer) with a black center that appears after the small blisters.

5. Inhalation(Pulmonary) anthrax Infection usually develops from 1 to 7 days When a person breathes in spores. Considered to be the most deadly form . starts primarily in the lymph nodes in the chest before spreading throughout the rest of the body. Symptoms: - Fever and Chills. - Cough. - Chest Discomfort . - Shortness of breath. - Body aches .

6. GIT (Intestinal) anthrax Infection usually develops from 1 to 7 days When a person eats raw or undercooked meat from an animal infected . rarely form been reported. Once ingested, spores affect the upper GIT tract : esophagus, stomach, and intestines. Symptoms: - Fever and chills. - Swelling of neck or neck glands. - Sore throat Painful swallowing. - Bloody vomiting. - Diarrhea or bloody diarrhea.