Module #5-Path: furncale and carbuncle Flashcards
Gram Positive Bacteria are considered an exotoxin, what are the gram positive bacteria?
Staphylococci
Streptococci
Corynebacteria Diptherae
Actinomyces Israelii
What is the pathogenesis for gram positive exotoxins?
Superantigens
Give an example of a gram positive bacteria exotoxin infection
Toxic Shock Syndrome: intravaginal tampon if left too long leads to growth of staph aureus —- leads to release of exotoxin in circulation — leads to conjunctivitis and vomiting
Gram negative bacteria are considered an endotoxin, what are the gram negative bacteria?
N. meningitides N. Gonorrhoea Salmonella Typhi Klebisella, E. coil, Pseudomonas (bronchopneumonia) Bartonella Henslae
What is the pathogenesis for gram negative endotoxin
Possess a lipopolysaccharide wall (LPS). Bacteria lysis leads to large amounts of LPS in blood — this binds with lipopolysaccharide binding protein (LBP) forming an LPS-LBP complex — LPS-LBP is picked by macrophages that release TNF – damage of endothelium —– PMNs bind onto damaged epithelium —-release IL-1 procoagulant factor —DIC
What is the importance of infectious diseases?
Major problem in spite of improved living conditions, vaccinations, antibiotics
More than 10 million deaths/yr in developing countries
New and fatal infections ares still being recognized
What are some barriers to bacterial invasion?
Skin-Keratin Layer
IgA in mucosa, mucus in gut, lungs
Ciliary movement in bronchial passages
Normal Commensals
What are the steps in the diagnosis of infectious disease?
Clinical features: hx, PE
Knowledge of epidemiology: common infections in the geographic area
Isolate the organism: pus, bl, tissue, fluids
Ab response: demonstrate rising titers
Biopsy
Therapeutic response
What are key cells seen in bacterial, viral and fungus infections?
Bacterial: polymorphonuclear Leukocytes
Virus: Macrophages, lymphocytes
Fungus: mixed PMN + lymphocytes + Macrophages + Giant Cells
Bodies response to infection differs depending on the organism. What is the difference between a local and a systemic infection ?
Local: inflammation at the site of infection
Systemic: Response to infection
mediated through cytokines, fever/headache/leukocytosis, increased metabolic rate and memory cells for the future
How can infections spread through the body?
Lymphatics: Lymphadenitis (local and distant)
Venous (regional veins, thoracic duct) – reach vena cava and R heart —- right sided valve = endocarditis
Reach the lung and pulmonary artery and produce lung abscess
Through pulmonary veins – L sided heart (mitral, aortic valve) = endocarditis
Distant abscess: brain, kidney, spleen, brain
What is bacteremia?
Spread of bacteria in blood
–bacteria destroyed by immune system = no symptoms
What is septicemia?
Bacteria in blood multiply
- -usually accompanied by fever, chills = serious condition
- -can set up distant foci of spread in other tissues = septicemic abscess
What are the steps in a bacterial infection?
Enter the body: ingestion, inhalation, and inoculation
Multiply locally
Spread: lymphatics, blood (plasma, RBC, leukocytes), nerves
Tissue planes, BMs, pleura, pericardium, peritoneum, meninges
What are the types of tissues responses (to damage)?
Acute inflammation: bacterial Lymph Mononuclear: Virus Granulomatous: TB Mixed acute/chronic:Fungus Eosinophils: parasites Fibrosis: Schistosoma Necrosis: Clostridia (Gas gangrene) Pseudomembrane: diphtheria, Clostridium difficile