Microbiology TEST 1
Microbiology 4th Semester
Microbiology 4th Semester
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Cartes-fiches
Explain term antitoxin
- antibody that has ability to neuralize specific toxin
Explain active immunization
- protection against disease, may last for years in some cases even for life
- stimulation with specific antigen to promote antibody formation in the body
Explain term Zoonosis
is the direct or indirect transmission of infection or diseases from animal to human
Explain term passive immunity:
provide IgG antibodies to protect against infection
- is a short-lived protection
Explain term natural passive immunity:
maternal antibodies (IgG) protect the newborn baby
Explain term acquired passive immunity
obtaining serum from immune individuals and then injecting it to protect a susceptible person
For Active Immunization we use 4 different contents
- non-virulent or attenuated (abgeschwächt) pathogen
- killed/inactivated pathogen
- toxoid
- bacterial protein or polysaccharide
What is the name of the vaccination for corynebacterium diphtheriae and what is in it ?
- DTaP vaccine (Diphtheria toxoid, Tetanus toxoid , Pertussis antigens)
- toxoid
toxoid - bacterial toxin whose toxicity is supressed or weakened
What are systemic complications of diphtheria ?
- severe form of primary disease due to unimmunization or immunosuppressed patients
- involve neurvous and heart system
- heart -myocarditis
- neurvous system - neurotoxicity - neuropathy
Why diphtheria is considered potentially fatal disease?
fatal in unimmunized and immunosuppressed patients
(asymptomatic in immunized)
myocobacteria are gram-positive rods that stain ?
acid-fast staining
mycobacteria
Mycobacteria are slow growing or fast growing?
slow growing
Lipids-rich cell wall of mycobacterium are responsible for characteristic properties of bacteria
Is ist true that there are nontuberculous mycobacteria (NTM) ?
nontuberculous mycobacteria (NTM) are also named ?
MOTT - mycobacteria other than tuberculosis
Explain granulomatous infection:
chronic inflammatory reaction:
- protective response to chronic infection or foreign material
- preventing dissemination and restricitng inflammation
Name the two acid-fast satining bacteria
- nocardia
- mycobacterium
What is the meaning of slow growth in mycobacteria ?
- infection is an insidious, chronic process
- taking several week or months to become apparent
Mycobacterium, Nocardia and Listeria monocytogenes are all ?
FACULTATIVE INTRACELLULAR ORGANISMS :
- bacteria phagocytosed but
- they inhibit phagsome-lysosome fusion
- inside these cells bacteria are safe from antibodies and other immune defense
- and in macrophages can multiply
- therefore all three bacteria are CATALASE-POSITIVE
Mycobacterium most commonly infects the
lungs - explains why they are obligate aerobe
The Virulence factor "sulfatides" is responsible in mycobacterium tuberculosis to ?
- inhibit phagosome-lysosome fusion
- is a sulfat group attached to the CORD FACTOR
- therefore this is the factor who causes mycobacterium to be a facultative intracellular organism
Cord factor is a virulence factor in mycobacteria name its function
- 2 mycolic acids bond to a disaccharide - trehalose
- bacteria grow parallel to each other forming a cord
- inhibit neutrophil migration
- releases tumor necrosis factor - causing weight loss
Mycobacterium Tuberculosis and Croynebacterium diphtheriae have the same reservoir
only HUMAN
Mycobacterium tuberculosis transmission
-close / direct
- inhalation of respiratory droplets
Virulence Factors of mycobacterium tuberculosis : 5
- Catalase und superoxide dismutase
- WAX D - mycosides acts as adjuvant (enhances antibody formation to an antigen)
- Cord Factor - inhibiting neutrophil migration, release of necrotizing tissue, parallel growth of bacteria
- Sulfatides - inhibits phagosome-lysosome fusion - making them to
- mycosides - mycolic acid plus carbohydrate
- Facultative Intracellular organism
What are the virulence factors that allow the mycobacterium tuberculosis to survive in the macrophage?
- mycolic acid (sulfatides)
- catalase
- superoxide dismutase
Does mycobacteria tuberculosis have exotoxine?
NO they don't have toxins AT ALL
What for stands MTB ?
mycobacterium tuberculosis
Which mycobacterium infects humans due to contaminated milk from cows ?
Mycobacterium tuberculosis describe 1st pathgenic process of infection
1st facultative intracellular growth:
- aerosolized droplet nuclei from infected adult inhaled (when hesings,laugh,coughs, talks)
- enter area with highest air flow in lungs
- macrophages and neutrophils phagocytose but bacteria inhibits phagosome-lysosome fusion
- bacteria can multiply and enter lymphatics and bloodstream
- spreading to other organs, localized lymph nodes and other areas of lung
Mycobacterium tuberculosis describe 2nd pathgenic process of infection
2nd cell-mediated immunity:
- macrophages able to lyse some bacteria
- bringing fragments of bacteria to localized lymph node
- here T- helper cells multiply and send into circulation to look for bacterial antigen
- finding bacterial antigen T-cell secretes lymphocines
- attrackting macrophages
- macrophages destroy bacteria forming caesous necrosis
- a necrotized tissue that looks like granular creamy cheese/ firm, dry mass
Mycobacterium tuberculosis in primary tuberculosis the hallmarks are?
- most patients asymptomatic
- formation of scars at infected loci when recovery/healing of tuberculosis or
- caesous necrosis where bacteria remains in dormant state
- as long as immune system is active and functions normally >NO DISEASE symptoms
- when immune system is suppressed > primary progressive tuberculosis will develop
Primary tuberculosis but can also be symptomatic explain signs:
- usually in immunosuppressed, children and elderly
- not a power-full cell-mediated immunty (macrophages/neutrophiles attack)
- symptoms are pneumonitis, cavitations with fluid-filled
Primary progressive tuberculosis characteristics
- patients immune system is not active or not functioning normally
- usually in malnurished children
- happens to 5% of infected MTB
- causes Miliary TB and Meningitis TB
Miliary Tuberculosis means:
- patient is HIGHLY CONTAGIOUS
- tiny millet-seed-size tubercles (granulomas) spread over entire lungs
- and disseminated to other organs (kidney,liver etc.)
Miliary tuberculosis also named
haematogenous spread
Miliary tuberculosis can appear in primary or secondary tuberculosis
in both
Secondary tuberculosis what are its characteristics ?
- reactivation of MTB from dormant state
- usually in people with low cell-mediated immunity (HIV, AIDS)
- or temporary weakend immune system
In secondary tuberculosis what happens to the caesous necrosis ?
- it liquify and MTB can multiply extracellular
- forming cavitations
- can be exposed in Chest radigraphs or CT scans
