Unit 4: Pathogenesis of Bacterial Infection Flashcards
Microorganisms that cause disease
Pathogens
The source or cause of an illness or abnormal condition
Pathogenesis
Pertaining to the ability of the pathogenic agent to cause disease by overcoming host defenses
Pathogenicity
The relative ability of a microorganism to cause disease; the degree of pathogenicity
Virulence
Pertaining to a very pathogenic or rapidly progressing condition
Virulent
The process by which certain cells of the body engulf and destroy microbes
Phagocytosis
Phagocytic cells:
Macrophage and Neutrophils
An infection that occurs as the result of medical treatment or procedures
Iatrogenic infection
Attachment of bacteria to host tissues at their portal of entry
Adherence
Organisms recognized to cause disease in healthy immunocompetent individuals a high percentage of the time
True pathogens
Examples of true pathogens:
Yersinia Pestis and Bacillus anthracis
Also called as “opportunists”
Opportunistic pathogens
Microorganisms that usually do not produce disease but are capable of causing disease in an individual whose immune system is compromised
Opportunistic pathogens
Examples of Opportunistic pathogens:
*Neisseria meningitidis
*Escherichia coli
An opportunistic pathogen that is usually harmless in the Respiratory Tract, but can cause meningitis
Neisseria meningitis
E.coli can cause:
Urinary Tract Infection (UTI)
Microorganisms which will not cause disease naturally, but it will affect the patient if they become immunocompromised
Opportunistic pathogens
Portals of entry:
- Mucous membranes - Respiratory tract, Gastrointestinal Tract, Genitourinary Tract, Conjunctiva
- Skin - Unbroken skin, Hair Follicles, Sweat galnd ducts
- Parenteral route - Punctures, injections, bites, cuts, wounds, surgery
Easiest and most frequently traveled portal of entry for infectious microorganisms
Mucous membranes
Diseases that are commonly contracted via Respiratory Tract:
Common Cold, pneumonia, tuberculosis, influenza, and measles
Microorganisms can gain access to the GI tract in food and water and via:
Contaminated fingers
Microbes in the GI tract can cause:
Poliomyelitis, Hepatitis A, Typhoid fever, Amebic dysentery, Giardiasis, Shigellosis (Bacillary dysentery), Cholera
Function of the acidity of the stomach:
When we intake microorganisms, if the stomach is acidic, then the microorganism will die because our stomach contain hydrochloric acid and enzymes, or by bile and enzymes in the small intestine. Those that survive can cause disease
