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all cocci have what morphology?
nonmotile, no spores and gram positive
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Staph?
means grapes and are catalase positive.
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staphylococcus aureus
1. morphology
2.virulence factors?
3.enzymes?
- 1. Gram +
- requires simple media
- catalase +
- can tolerate high salt
- 2. •Structural
- –Protein A
- »All over the surface of the organisms
- »Binds to the Fc region of antibodies
- »Prevents phagocytosis
- »Chemotactic factors—leads to pus
- –Capsules
- »Prevent phagocytosis non-sufficient contact between phagocyte and bacteria
- »Opsonins negate this
- •Enzymes
- –Coagulase »Cause coagulation of the blood»Reacts with fibrinogen. creates clot for them to grow in.
- –Hyaluronidase-hydrolysis of hyaluronic acid. breaks down goo.
- –Staphylokinase-dissolve the fibrin clot. goo that surround your cell.
- –Lipases-dissolve lipids-dissolve antibacterial lipids so found on skin so they can break out of the clot.
- –Beta-lactamase - breaks downs Ab
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staphylococcus aureus
toxins?
- •Toxins
- –Exfoliatoxin-causes the skin to slough off
- –Hemolysin »Cause lysis RBCs
- »Can also cause the lysis of WBC
- –Pyrogenic toxins
- »Produce fever and Rash
- –Toxic Shock Syndrome Toxins (TSST-1)
- binds to TCell making them crazy
- •Enterotoxins
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staphylococcus aureus
initiation of infection?
host and tissue specificity?
infections?
- –Initiation of infection
- •Through breaks in the skin
- –wounds, burns, surgery
- –Host and Tissue Specificity•Humans primarily•No tissue specificity•Most infections are of the skin•Many people are nasal carriers
- –Infections
- •Most common-pimples, boils, carbuncles, urinary tract infections and impetigo, scaled skin syndromes
- •Systemic-diseases usually caused by the spread from a skin infection
- •Bacteremia-growing in the blood
- •Endocarditis–Attack the lining of the heart and the valves–Blood pumped from the heart drops–50% of the patients die
- •Pneumonia–Infection spreads to the lungs–Fills with fluid–Causes them to fill with pus (10% of patients)
- •Osteomyelitis–Infects the bones–Associated with a high fever
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Streptococcus
- –Strep are divided into serological groups based on antigens
- •These are called Lancefield serological groups
- they have different antigen in their bodies
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Streptococcus pyogenes (Group A)
Morphology?
Cultural characteristics?
- •Morphology
- –Gram +
- –Catalase negative
- •Cultural characteristics
- –Require complex media, all strep like blood agar.
- –Beta hemolytic
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Streptococcus pyogenes (Group A)
Virulence Factors?
- •Virulence Factors
- –Protein M-this is a membrane bound protein
- »Is found on the organisms Fimbriae
- »Stops complement fixation
- »Stops opsonization
- –Capsule
- »Made of Hyaluronic Acid (like our cells so wbc ignore it)
- –Enzymes
- »Streptokinase
- »DNAase
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Streptococcus pyogenes (Group A)
Toxins?
Initiation of infection?
- •Toxins
- –Pyrogenic toxins-
- »Produces rash of scarlet fever
- »Type IV hypersensitivity
- –Streptolysin
- »Lysis of RBC, WBC and platelets
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Streptococcus pyogenes (Group A)
Diseases?
- •Diseases
- –Pharyngitis
- »Strep throat
- –Scarlet Fever
- –Pyoderma
- »Also called impetigo
- –Erysipelas
- »spreads to the lymph nodes
- –Necrotizing Fasciitis
- »Flesh eating bacteria
- »Breaks down the fascia
- »Connective tissue that surrounds the muscle
- »Done with a toxin
- »Results in a Toxemia
- –Rheumatic Fever
- »A complication of pharyngitis
- »Autoimmune disorder
- –Glomerulonephritis
- »Type III Hypersensitivity
- »This causes inflammation of the nephrons
- »Results in high blood pressure and low urine output
- »Could cause irreversible kidney damage
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Streptococcus pneumoniae
Morphology?
- •Morphology
- –Gram positive
- •cultural characteristics (needs complex media)
- –Catalase negative
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Streptococcus pneumoniae
Virulence Factors?
Diseases?
- –Virulence Factors
- •Capsular polysaccharide
- –Antiphagocytic(most important)
- •Toxins
- –Pneumolysin
- »Hemolysin-produces alpha hemolysis on blood
- »High concentrations can be lethal
- –Diseases
- •Leading cause of bacterial pneumonia
- •Sinusitis-infection in the sinuses with pus
- •Otitis media-infection in the middle ear with pus
- •Bacteremia-gets in the blood
- •Endocarditis-infects the lining of the heart
- •Pneumococcal meningitis
- –From sinusitis or otitismedia
- –Gets into the meninges
- –Highest rate of death from meningitis
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Streptococcus agalactiae
Morphology?
- •Morphology
- –Gram +
- –cocci
- –grows in chains
- –catalase negative
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Streptococcus agalactiae
Diseases?
- •Diseases
- –Usually newborns (3 out of 1000)
- infects babies coming down birth canal
- –Puerperal fever
- »Childbirth fever
- »In women following childbirth
- –Immunocompromised
- »Another high risk group
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Viridians Streptococcus
Morphology?
Diseases?
- •Morphology
- –Gram +
- -Cocci
- –catalase negative
- •Normal flora
- –Mouth
- –Teeth
- –GI tract
- –Pharynx
- –Genitals
- –Urinary tract
- •Diseases
- –Endocarditis
- –Dental caries»Cavities
- –Form biofilms on teeth»Plaque
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Streptococcus Mutans Group
- •Produce organic acids
- –Decalcify the teeth
- –Causes tooth decay
- –High sucrose diets create more acid
- Live in biofilms
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Bacillus anthracis (anthrax)
Morphology?
Cultural characteristics?
- –Morphology
- •Straight rods in short chains
- •Gram positive
- –Cultural characteristics
- •usually strict aerobes
- •Endospore formers
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Bacillus anthracis (anthrax)
- –Infections
- •Pulmonary Anthrax (inhalation)
- –Woolsorter’s disease (nickname)
- –Inhalation of endospores
- –Caused by inflammation of tissues separating the two lungs
- –Can lead to hemorrhagic meningitis and then death
- •Cutaneous Anthrax
- –Gets in scratches on the skin
- –Usually found in handlers of live stock
- »Causes a malignant pustule (neck)
- »Next can turn to local gangrene
- »Systemic
- »Death
- •Enteric anthrax
- –Rare
- –From eating undercooked meat
- –The symptoms are bloody stool and abdominal pain
- –Death
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Clostridium perfringens
Virulence factors?
- •Virulence factors
- »Necrotizing-destroys tissue
- »Hemolytic-lysis of RBC
- »Lethal-causes death
- »Enterotoxin-food poisoning
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Clostridium perfringens
Diseases?
Treatments?
- •Diseases
- –Gas gangrene
- »Spores get into tissue where there is little oxygen
- »Intense pain and swelling to start
- »This is caused by the tissue and muscle damage
- »Bacteria spreads to surrounding tissue
- »Production of a foul smelling gas
- »Can cause shock, kidney failure followed by death»Incubation 6 to 72 hours after inoculation
- •Treatments
- –Removal of foreign material and dead tissue (amputation)
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Clostridium tetani (tetnus)
- –Endospores get in a break in the skin or mucus membranes (no protein coat)
- Tetanus toxin
- –Muscles cannot relax
- toxin binds to neurons that produce inhibitory neurotransmitter.
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Clostridium tetani (tetnus)
Disease?
- •Disease
- –Incubation is a few days to a week
- –Initial signs are tightening of the jaw and neck
- »Lock jaw
- –Other signs
- include spasms, sweating, drooling
- –Gets worse cannot relax hands and feet
- –Die because you cannot exhale out
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Clostridium botulinum (botox)
Pathology?
- •Pathology
- –Enters the body by way of contaminated food–Ingestion of the toxin
- can pass through stomach because of protien coat around the toxin.
- »The toxin blocks the release of acetylcholine
- –Blocks muscle contraction
- –Flaccid paralysis- die when you can no longer breathe
- –Only 30 grams needed to kill everyone in the U.S.
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Actinomycetes
- (Gram +)
- –Can cause cavities
- –Can enter breaks in the mucus membranes or skin
- gets into wounds from dirt.
- •Actinomycosis
- •Forms abscesses
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Lactobacillus
- (Gram +)
- –Rods
- –Non-spore formers
- –Found in body as normal flora
- –Used in food industry
- •Pickles
- •Yogurt
- •Buttermilk
- •Sauerkraut
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clostridia all are?
- gram +
- strict anaerobes
- endospore formers
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listeria monoctogenes
1. morphology
2. diagnosis
- 1. small gram +
- rods
- gets in monocytes or epithelial cells.
- uses listerolysin O to get out of phagosome.
- takes over actin in the cell and makes pseudopodia to push into the cell.
- 2. most are asymptomatic
- dangerous for pregnant women, babies ans immunosuppressed.
- can go to brain
- can cross the placenta.
- can cause miscarriage or birth defects
- found all over the enviroment and in some types of foods.
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corynebacterium diphtheria
1. morphology
2. virulence
3. diagnosis
4. diseases
- 1. gram +
- v shaped to pleomorphic
- 2. diphtheria toxin
- gets into cell binds to ribosome and stops protein synthesis.
- 3. most people are asymptomatic
- if you are not the toxic causes the formation of the pseudomembrane.
- 4. respiratory
- -psuedomembrane on the tonsils or up the nose and palate.
- - cutaneous
- -toxin can go systemic = death
- this is found all over the enviroment.
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propionibacterium acnes
causes acne
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mycobacterium tuberculosis
1. morphology
2. infection
3. extra
- 1. gram + with extra thick cell wall so we say acid fast
- slender rods
- 2. primary infection
- starts out with inhalation of bacteria
- -only needs 10
- -this is airborne
- gets phagocytized by macrophages
- -grows inside then lyses the macs
- -more macs come and they are lysed
- -this happens over and over
- -you have cell mediated response which activates more macs
- the big mass of macrophages and mycobacterium create a tuberacle.
- -fibroblast cells put collagen around it
- -the center dies (caseous necrosis)
- -some people clear the infection and form the Ghon complex.
- secondary infection
- a tubercle that the person has had for years breaks open and spread to the rest of the lungs.
- disseminated
- when it spreads all over
- 3. diagnosis
- -skin test
- -extra = acid fast bacillus in sputum
- treatment
- -6 months of antibiotic treatment
- epidemiology
- -1/3 of the world has it
- -can live for 8 months on formites
- -spresd by cramped living conditions
- -50% of people that get it die
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mycobacterium leprae
1. diseases
2. diagnosis
- 1. tuberculoid leprosy
- -people with good immunity
- -not contagious
- -flat sores
- -lose some hair
- - might not notice
- -not progressive
- lepromatous leprosy
- -people with bad immunity
- -very bad lesions
- -spreads all over
- -contagious
- -loss of fingers and toes
- -all over face and ears
- 2. diagnosis
- skin test like TB
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mycobacterium avium
- respiratory diseases
- found primarily in AIDS patients
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