Microbiology TEST 1
Microbiology 4th Semester
Microbiology 4th Semester
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Flashcards
Which organ systems can be involved in tuberculosis after reactivating TB (secondary tuberculosis) ?
- pulmonary tuberculosis : infection grow,caseate,liquify,cavitate
- pleural and pericardial infection
- lymph node infection - most common extrapulmonary manifestation
- kidney - sterile pyuria
- skeletal - lumbar and thoracic vertebral disc destoryed
- joints
- CNS - meningitis
- miliary tuberculosis
Tuberculosis " RULES OF FIVE"
- droplet nuclei 5 micrometers & contain 5 MBT bacilli
- Patients infected with MBT have 5% risk of reactivation in first 2 years, and then 5% lifetime risk
- PAtients with HIV have 5 + 5% chance of reactivation every year!
BCG vaccination for tuberculosis contains
- viable, attenuated (abgeschwächt) M.bovis
- does not protect from tuberculosis it only stops DISSEMINATION of infection ( prevents haematogenous spread/miliary TB)
MOTT (mycobacteria other than tuberculosis) or NTM ( nontuberculosis mycobacteria) are atypical why ?
- because lack transmission from patient-to-Patient
MOTT are transmitted
1. air-born route - inhalation
2. or skin break / wound introduction of bacteria
MOTT are resistant to drug for tuberculosis but can be treated with
antibiotics
MOTT are saprophytically in ______ or ______?
soil or water
Mycobacterium Leprae grows
- intracellulary in skin histiocytes, endothelial cells and nerve cells
Mycobacterium leprae transmitted
directly and air-borne route
Mycobacterium leprae two form of disease:
- lepro-ma-tous leprosy
- tuber-cu-loid leprosy
mycobacterium leprae what marks lepromatous leprosy
- skin lesions cover the body with thickening and lumps
- face looks lionlike "leonine facies"
- nose = "saddlenose deformity"
- mostly effects skin,eyes, nerves and testes
Mycobacterium leprae causes lepromatous leprosy
- low cell-mediated immunity
- large number of bacteria in histiocytes
- lepromin-skin test -negative
Mycobacterium leprae causes tuberculoid leprosy name the characteristics
- localized superficial, unilateral skin and nerve involvement
- area with rash hairless + diminished sensation + enlarged nerves
Mycobacterium leprae causes tuberculoid leprosy
- high cell-mediated immunity
- few bacteria in histiocytes
- Lepromin-skin-test-positive
Actinomyces is endogenous or exogenous ?
endogenous - part of natural flora of GI, mouth( mucosal surfaces), female genital tract
Actinomyces israelii are:
Actinomyces israelii clinical presentation
Actinomyces israelii transmittion
endogenous infection
Actinomyces israelii causes unique granules name them and what are they made of?
sulfur granules
- consisting of bacterial colony
Nocardia asteroides virulence factor
- mycolic acid
- cord factor - multiply in macrophage and prevent phagosome-lysosome fusion
Nocardia asteroides reservoir
ubiquitous in soil rich in organic matter
Nocardia asteroides transmission
- air-born route - inhalation
- direct introduction into tissue
Nocardia asteroides is
Nocardia asteroides clinical presentation ?
- pulmonary / bronchopulmonary nocardiosis (pneumonia, lun abscesses )
- cutaneous nocardiosis (mycetoma - madura foot, chronic ulcerations, cellulitis)
Different name for mycobacterium leprae
hansen disease
Nocardia asteroides can cause secondary infection why ?
secondary infection : - brain abcesses / meningitis
due to dissemination following pulmonary nocardiosis
Listeria monocytogenes is
Infection with Listeria monocytogenes is by
- food-poisoning - ingesting contaminated food (milk, cheese, processed meats, raw vegetables)
- transplacentral spread from mother to neonate
Listera monocytogenes virulence factors
- internalins - protein that promotes own uptake from macrophage or enterocytes
- Listeriolysin O - pore-forming
- Phospholipase C - pore-forming
- facultative intracellular organism - prevent phagosome lysosome fusion
Listeriolysin O the virulence factor of listeria monocytogenes does what?
- pore-forming
- escapes phagolysosome of macrophages and avoid intracellular killing
- thus facultative intracellular organism
Listeria monocytogenes usually have a risk groups whose cellular immunity has defects name the groups
Which bacteria cause meningitis in neonates?
Transmission of listeria monocytogenes can be in three ways name them
- food-born route : contaminated cheese,milk, vegetables, meat)
- in utero/transplacentral infection of fetus from bacteremic mother
- vaginally - during birth
Most common clinical diseases caused by listeria monocytogenes are?
Listeria monocytogenes can grow in
Is listeria monocytogenes ß-hemolytic ?
yes, it is weakly ß-hemolytic
Listeria monocytogenes is motile and moves in a specific mannor explain:
end-over-end tumbling motion
What Virulence factor provides adhesion for listeria monocytogenes on the host cell surface ?
internalins
Listeria monocytogenes can cause disseminated disease is that true ?
yes , can spread to liver and spleen
Neonatal disease caused by Listeria monocytogenes can be divided into 2 forms name them
- early-onset listeriosis - in utero
- late-onset listeriosis- during birth or shortly after
