Exam 3 Flashcards
Asepsis vs sepsis
Aseptic Surgical Technique
asepsis: absence of significant contamination
sepsis: microbial contamination
Prevents Microbial contamination in wounds
Sterilization
Commerical sterilization
Disinfection
Antisepsis
Removal of all microbial life
Kills C. Botulinum endospores
removal of pathogen
removal of pathogens from living tissue
Degerming
Sanitization
Biocide/Germicide
Bacteriostasis
Removal of microbes from a limited area
Lowering the number of micrbial counts on eating utensils
Kills microbes
Inhibits microbes (does not kill)
Microbial control Agent
Alters membrane permeability
damages proteins
damages nucleic acids
Heat
Moist heat sterilization
Kills by denaturing enzymes and altering structures
Denatures proteins (autoclave: 121C for 15psi)
Pasteurization
Reduces spoilage organisms & pathogens
Except: Thermoduric organisms
Hepa vs membrane filtration
Hepa removes microbes >0.3um
Membrane filtration removes microbes >0.22um
Radiation
Ionizing
Nonionizing
Microwaves
Ionizing radiation: x-ray, gamma rays & electron beams
- Damages DNA
- Ionizes water to release OH
Nonionizing radiation: (UV, 260nm)
- Damges DNA
Microwaves: kills by heat but not really antimicrobial
Phenol & Phenolics
(Carbolic Acid)
Disinfectant
Disrupts plasma membranes
Halogens
Iodine
Alters protein synthesis & membrane
Iodine
Halogen
Chlorine
Oxidizing agents
Bleach
Alcohol
Ethanol & Isopropanol
Denatures proteins & dissolves lipids
Needs water
Heavy Metals
Ag, Hu, Cu
Ag: Silver nitrate
Hg: Silver sulfadiazine (topical cream on burns)
Cu: Copper sulfate, an algicide
Oligodynamic action
Denatures proteins
Denatures proteins
Denatures enzymes
Damages DNA
Disrupt plasma membranes
Alters Protein synthesis/membrane
Denatures proteins
- Oligodynamic action (Heavy Metals)
- Most heat
- Alcohol (Ethanol, Isopropanol)
Denatures enzymes
- Heat
Damages DNA
- Radiation (Ionizing & nonionizing)
Disrupt plasma membranes
- Disinfectant (Phenols & Phenolics)
Alters Protein synthesis/membrane
- Halogen (Iodine & Chlorine)
Alexander Fleming
Penicillium notatum
Chemotheraphy
Antimicrobial Drugs
Antibiotic
Selctive Toxicity
drug used to treat a disease
Interferes with microbial growth inside a host
Inhibits a microbe using small amount of substance produced by another microbe
Kills harmful microbes without damaging host
Antimicrobial spectrum
Broad spectrum - wide range (Gram - & Gram +)
Narrow spectrum - Limited range
Superinfection - Pathogen that has develped resistance to an antimicrobial drug
Bactericidal vs Bacteriostatic
Bactericidal kills microbes
Bacteriostatic inhibits micrbial grown
Antimicrobial Drug Actions
1) Inhibits cell wall synthesis
- Penicillion
- Bacitracin
- Vancomycin
- Cephalosporins
2) Inhibits protein synthesis
- Chloramphenicol
- Erthromycin
- Tetracyclines
- Streptomycin
3) Inhibits Nucleic Acid replication & Transcription
- Quinolones
- Rifampin
4) Injurty to plasma membrane
* Polymyxin B
5) Inhibits synthesis of essential metabolites
- Sulfanilamide
- Trimethoprim
Antibiotic Drug Actions
Inhibits Protein synthesis
Chloramphenicol: Inhibits formation of peptide bond (50s)
Streptomycin: Changes shape of 30s and reads mRNA code incorrectly
Tetracycline: Interferes with tRNA & mRNA attachment - ribosme complex
Penicillin
Prevents cross linking of peptidogycan (mostly Gram +)
Natural
Semisynthetic
Extended spectrum
Penicillin G (requires injection)
Penicillin V (requires Oral)
B-Lactam Ring: Common nucleus
Cell Wall synthesis inhibitors
Antimycobacterial antibiotics
- Isoniazid (INH): inhibits mycolic acid synthesis
Ethambutol
- Inhibits incorporation mycolic acid
Protein synthesis inhibitors
Aminoglycosides
- Changes 30s subunit shape (Broad spectrum)
- Streptomycin
- Neomycin
- Gentamyci
Competitive Inhibitors
Sulfonamides
- Inhibits Folic acid synthesis
- Broad Spectrum
Action of Enzymes inhibited
Antiviral Drugs
Protease inhibitor
- Indinavir (HIV)
Integrase Inhibitor: (HIV)
Attachment inhibition
- Zanamivir (Influenza)
- Block CCR5 (HIV)
Uncoating inhibition
- Amatadine (Influenza)
Antibiotic Resistance
1) Blocks entry
2) Inactivates enzymes
3) Alters target molecule
4) Ejects antibiotic
Pathogenicity
Virulence
Portals of Entry
Ability to cause disease
Extent or degree of pathogenicity
MM, Skin, Parenteral route
Portals of Entry
MM
- Respiratory Tract: measles & Small pox
- GI Tract: Hep A, Poliomyelitis, Typhoid fever, Amoebic dysentery, Cholera
- Genitourinary Tract: HIV, warts, herpes
- Conjunctiva: Trachoma
Dose Dependent Onset
ID 50 (Infectious Dose) - causes disease in 50% of pop.
LD 50 (Lethal Dose) - Lethal dose in 50% of pop.
Microbial Attachment (Adherence)
Adhesin aka Ligand binds to specific surface receptor of host tissue
Capsule
increases virulence and inhibits phagocytosis
Streptococcus pneumoniae
Klebsiella pneumoniae
Haemophilus influenza
Anthracis
Yersinia Pestis (Plague)
Virulent vs Avirulent
Encapsulated vs unencapsulated strains
M Protein
Another virulent factor
Heat & Acid resistant protein on cell surface and Fimbriae (Streptococcus pyogenes)
Attaches to epithelial cells and resists phagocytosis
Opa protein
Waxy Lipids
Outer membrane of Neisseria gonorrhoeae
Bacteria fimbriae attaches to host
Mycolic acid (mycobacterium tuberculosis)
Resistant to phagocyte digestion and can multiply inside
Enzymes
Production of extracellular enzymes = Exoenzymes
digest materials b/t cell and formed blood clot
digest blood clots
Hyaluronidase
- Exoenzyme that hydrolyzes hyaluronic acid.
- Assist in spreading
- Blackenng of infected wounds
- Clostrida = gas gangrene
Collagenase
- Exoenzyme that breaks down protein collagen (forms connective tissues)
- Clostridium assists in spread of gas gangrene
Kinase
- Breaks down fibrin and digest clots that isolates the infection
- (Streptococcus pyogenes)
- (Staphyloccus aureus) - breaks down clot in heart attacks
Coagulase
Bacterial Enzyme that coagulates fibrinogen in blood
Clot protects bacteria by isolating from host defenses
(Staphylococci)
IgA Protease
Exoenzyme, breaks down immunoglobulin A (IgA) found in mucosal membrane surface
IgA, Prevents adherence of pathogen
N. Gonorrhoeae & N. meningitidis produces IgA protease
Antigenic Variation
Pathogens that can alter surface antigens and evades adaptive immune system
Pathogen is unaffected by antibodies
Influenzavirus
N. Gonorrhoeae
Trypanosoma brucei (african sleeping sickness)
Leishmania donovani
Toxins
Posionous substance produced by microbes
- Transported by blood and Lymph
- (Fever, Diarrhea, Shock)
- Inhibits protein synthesis
- Destroys blood cells/vessels
- disrupt nervous system
Exotoxin
Exotoxins - toxins are produced inside bacteria cell and is secreted out
- Gram - & Gram +
- Protein but acts as enzyme
- Destroys particular host cell
- inhibit certain metabolic functions
- highly specific
- extremely lethal
- soluble
- Botulism - by ingesting exotoxin
- Most are A-B toxins
A-B Exotoxin
- A: enzyme aka active, inhibits protein synthesis in host cell
- B: binding
Types
Membrane disrupting toxin
- lysis host cell by forming protein channels in plasma membrane
- Others disrupt phospholipid
- Leukocidin (Staph & Strep)
- Hemolysin (Staphy & Strep)
- Streptolysin (Strep)
Superantigens
- Provoke intense immune response
- Stimulates T-cell and releases cytokines (fever, nausea, vomit, diarrhea, shock, death)
- Staph cause food poisoning & TSS
Endotoxin
Endotoxins - outer membrane is the toxin that breaks apart
- Gram - (Lipid A)
- Lipoplysaccharides (exo are protein)
- released when bacteria dies
- Stimulates macrophages to release high concentrated cytokines (toxic)
- Activates blood clotting protein which leads to necrosis of tissues (DIC)
- Chills, fever, weakness, aches, shock, death, miscarriages
- Pyrogenic response by producing prostaglandins from hypothalamus
Pathology
Etiology
Pathogenesis
Infection
Disease
Study of disease
study of cause of disease
development of disease
colonization of pathogens
abnormal state where body is not functionally normal
Vaginal lactobacilli
Rapid multiplication just before birth
Normal Microbiota
The first microorganism newborns come in contact with
Transient microbiota
Normal microbiota
Symbiosis
Presents temporarily, days, weeks, months
Permanet colonization
Relationship b/t normal microbiota & host
Commensalism Symbiosis
Mutualism Symbiosis
Parasitism Symbiosis
One organism benefits/other is unaffected
both benefits
One benefits at the expense of other
Normal Microbiota
Distribution & Compostion dependent on
- Nutrients
- Physical/Chemical/Mechanical factors
- Host defenses
Koch’s Postulates
Same pathogen must be present in every disease
Must be isolated from diseased host and grown in pure culture
Must cause same disease when inoculated to another animal
Must be isolated again and show its the same disease from original animal
Symptom
Signs
Syndrome
Change in body function felt by patient. Non measurable
change in body that is measured or observed as a result of disease
Specific group of signs & symptom that accompies a disease
Communicable Disease
Contagious disease
Noncommunicable disease
Spreads from one host to another
easily spread from one host to another
non transmitted disease
Incidence
Prevalence
Sporadic disease
Fraction of pop. contracts disease during specific time
Fraction of pop. having specific disease at a given time
Disease occuring occasionally in population
Endemic Disease
Epidemic disease
Pandemic disease
Herd immunity
constantly present disease
acquired by many host in a short time
worldwide epidemic
immunity in most population
Acute
Chronic
Subacute
Latent
Symptoms develop rapidly
disease develops slowly
b/t acute and chronic
period of no symptom or inactive
Local infection
Systemic infection
Focal infection
Limited to a small area of body
throughout the body
System that began as local infection
Sepsis
Bacteremia
Septcemia
Toxic inflammation arising from spread of microbes.
Bacteria in blood
Growth of bacteria in blood
Toxemia
Viremia
Toxin in blood
Virues in blood
Primary infection
Secondary infection
Subclinical disease
Acute infection with inital illness
Opportunistic infection after primary infection
No noticeable signs or symptoms
Incubation period
Prodromal period
Convalescence period
no sign
mild symptom
Recovery
