Differentiate between the structure pathogenic properties and mechanisms by

Differentiate between the structure pathogenic

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Differentiate between the structure, pathogenic properties and mechanisms by which bacteria, viruses and fungi cause disease. Organism StructurePathogenic PropertiesBacteriaBacteriaUnicellular-Prokaryotic(no nucleus).-Rigid outer wall,(made of peptidoglycan). This is action site of someabx. ONLY produced by bacteria.CocciRound sphericalStrep-chain Staph-clusterBacilliRod shaped-e-coli.SpirochetesHelical (spiral)-syphilisPolymorphicNo specific shape and no rigid cell wall-mycoplasmpna.DiplococcipairsGram negative.-Don’t retain gram stain-Cause fever, dic, septic shock.-Outer membrane is made oflipopolysaccharide, which activates almost every aspectof inflammation (cytokines, TNF, IL).-Have extra membrane making them more resistant to abx than gram +.-Ex- Neisseria (gonorrhea, meningitis), salmonella, shigella, & klebsiella.Gram positive.Retain gram stain-purpleLack extra cell to release cytotoxins.Some secrete teichotic acid=protects from lysis.Ex- Strep, staph, bacillus(anthrax), clostridium(tetanus)Acid Fast Bacilli (AFB)-Thick walls made of lipids which allows them to take up stain fast.
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-Grow very slow. (thickness)-Abx=months – years.-Cultures=8weeks.-Ex- M. Tuberculosis, M. Laprae(leprosy), M. Avium.VirusConsist of nuclei acid protected by protein shell (capsid)Some have protective envelope surrounding capsid.Envelope-plasma membrane from previously infected cell.Most common in humansSpread from person to person or from animal, also from vector (mosquitos).Life cycle=intracellular-attachment to target cell-penetration-uncoating-rlease of viral nucleic acid from capsid-replication-synthesis of viral proteins and MRNA-Assembly- formation of new virons.-release- lysis or budding.Rapidly proliferate(multiply)and produce more virons than immune system can handle.Hide with in cells and away from immune and inflammatory responses.Frequent antigen shifts/driftsSuppress immune sys.Coat with self-proteins similar to normal cells.Self-limiting.FungiEukaryotic (nucleus)Thick rigid wallsDx by microscopic obs.Treated with potassium hydroxide to visualize
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Antifungals treat deep or systemic infx. And are toxic to host cell. Fungal cell is similar to human cell. Candid albicans= most common cause of fungal infx. -opportunistic yeasts. -skin, gi, mouth, vagina. -overgrowth. -neutropenic or immunosuppressed may have disseminated infix. (spread) -Candida=most common infx in people with cancer and hiv. d. Identify the clinical manifestations associated with infectious diseases.
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