Bacteria in the Respiratory Tract II Flashcards
Tuberculosis is characterized by __________ and _________
caseation necrosis and granuloma formation
The mycolic acid of M. tuberculosis is responsible for the bacteria’s resistance to
A. Host Defenses
B. Antiviral action
C. Antibiotics
C. Antibiotics
Tuberculosis can infect up to ______ people/year
A. 7-10
B. 10-15
C. 15-20
B
What environmental factors contribute to the risk of TB transmission?
Temperature, humidity, O2, radiation
_________ MTB have a higher risk of transmission as compared to _____ MTB
Drug resistant, drug susceptible
Duration and intensity are ______ risk factors of Tubercolosis.
Exposure
Which Immune cell mainly responds to tuberculosis infection?
A. CD4
B. CD8
C. APC
D. Th1
A. CD4
______ is an MTB-presenting cell which releases ______ which stimulates _______. It then stimulates release of ______ which release _______.
A. APC, Th1, Interferon, IL12,CD4
B. APC, IL12, Th1, Interferon, CD4
C. APC, Th1, IL12, CD4, Interferon
D. APC, IL12, Th1, CD 4, Interferon
D. APC, IL12, Th1, CD 4, Interferon
Enumerate some of the actions employed by the immune system in response to tuberculosis infection.
- Inhibition of Ca2+ Signals
- Blockage of recruitment and assembly of fusion mediating proteins
- Granuloma formation
- Killing of intracellular mycobacteria
CD__: Fas independent
CD__: Fas Dependent
CD8+
CD4-8-
What conditions must be met for tuberculosis to progress to secondary tuberculosis?
- Host factors (Low immune response)
- Agent factors (more virulent, more resistant)
People who have had _______ are at higher risk for getting drug-resistant TB
Previous TB treatment
In extrapulmonary TB, infection can be found where?
Lymph nodes, GI, CNS, genitourinary
A doctor orders you to do an AFB smear on a CSF specimen. However, you recall that AFB smear is only done on sputum specimens. Should you do the AFB smear and why?
Yes, because the infection may have spread to the CNS
Which AFB smear requires a heating-step?
Ziehl-Neelsen
This technique is also referred to as ‘cold’ acid-fast stain
Kinyoun Stain
________is used to report AFB microscopy
Direct sputum smear microscopy
What are the limitations of AFB?
- Not specific to mycobacteria
- less sensitive and specific than culture
MTB: ___ grower
NMTB: _____ grower
rapid grower
slow grower
What is the WHO recommended media for TB?
Broth media
What is the egg media for TB called?
Lowenstein-Jensen medium
What is the recommended diagnostic test by DOH for TB?
Xpert MTB/Rif Assay
Chest X-ray: ____
AFB Smear: _____
Positive
Negative
TRUE OR FALSE: Chest X-ray can distinguish between active and latent infection
False
What laboratory test is used to test for extrapulmonary tuberculosis, and is the indicator?
Histopathology
Granuloma or Caseation Necrosis
What samples are sent for Interferon-gamma release assay (IGRA)?
Blood and antibody
2-phase chemotherapy consists of ____ phase and ____ phase
intensive and continuation
The continuation phase for TB Treatment is used to kill _____ to prevent ____
persisters, relapse
MDR TB is resistant to ______ and ______, the most potent anti-TB drugs
INH (Isoniazid) and rifampicin
TRUE OR FALSE: Based on culture-positive PTB results, there was no evidence of a decline in the PTB Prevalence rates in the 2016 NTPS compared to the 2007 NTPS.
TRUE
What are the 5 key elements in DOTS?
- Government Commitment
- Case detection by sputum microscopy
- Standardized 6-8 month treatment regimen
- Regular, uninterrupted drug supply
- Standardized surveillance and Monitoring
What are the steps in the DOH program for TB Control?
- Screening
- Testing
- Treatment
- Prevention
Intensified TB Case Finding is done in health facilities, meanwhile Enhanced TB case finding is done in?
House-to-house visits using symptom screening
The first isolated Mycoplasma spp. was from bovines as pleuropneumonia and was deemed as _______
Eaton agent (M. pneumoniae)
Define pleomorphic
occurring in different forms
_________ has a fried egg colony appearance
Mycoplasma spp.
Mycoplasma: ___ pH
Ureaplasma: ____pH
6-8
5.5-6.5
Pleuropneumonia-like (PPLO) broth or agar contains _______ and ______
yeast extract and horse serum
Mycoplasma are fastidious organisms which require ______ for membrane function and growth
Sterols
Modified New York City Agar is similar to ____
modified Thayer-Martin
All of the following Mycoplasma species occupy the urogenital tract EXCEPT:
A. M. hominis
B. M. pneumoniae
C. U. urealyticum
D. U. parvum
B. M. pneumoniae
What is the primary metabolite of M. pneumoniae?
Glucose
Which two mycoplasma species are known human pathogens?
A. M. pneumoniae and M. genitalium
B. M. genitalium and M. hominis
C. M. pneumoniae and M. hominis
C. M. pneumoniae and M. hominis
What is the smallest free-living organism in nature?
Mycoplasma spp.
_____ is the normal laboratory contaminant
B. subtiis
Mycoplasma species are extremely sensitive to drying due to ________
The lack of cell wall
The transport medium for mycoplasma consists of ______
Trypticase soy broth with 0.5% albumin and penicillin
Due to the lack of cell wall, antimicrobials targets _____ and _____ of mycoplasma
Protein synthesis and DNA gyrase
Mycoplasma is usually treated with ______
macrolides, tetracyclines, or fluoroquinolones
For bacteria with cells walls, which type of antibiotics are usually used?
Beta Lactam and vancomycin
Which of the following targets the DNA gyrase?
A. Macrolides
B. Tetracyclines
C. Fluoroquinolines
C. Fluoroquinolones
Which Mycoplasma spp. causes primary atypical pnuemonia in young adults?
Mycoplasma pneumoniae
Due to the _________ , Mycoplasma pneumoniae do not take up dye under gram staining
lack of proper rigid cell wall
M. pneumoniae is osmotically _____ in the external environment
Unstable
M. pneumonia is the leading cause of _______
community-acquired pneumonia
Adhesion Protein (P1) of M. pneumoniae attaches through interaction with ______
neuramic acid
To avoid the battlefield, M. pneumoniae sneaks into the ______ where they remain dormant or replicate intracellularly
lung cells
Atypical pneumonia is also called _____
Walking pneumonia
Incubation period for M. pneumoniae
2-3 weeks
In chest x-rays of patients diagnosed with M. pneumoniae, what signs indicate infection?
Patchy infiltrates
Eaton’s Agar media is rich in _____ and ____
Cholesterol and nucleic acid
Which is more frequently done, culture or cold agglutinin test
Cold agglutinin test since it is faster than culture
In cold agglutinin test, IgM antibodies against bacterial antigens cross-react with _____
Human RBC antigens
For M. pneumonia, antibiotics like _____ are inefficient. Hence, antibiotics that ______ are used
beta-lactam antibiotics (cell wall inhibitors)
inhibit protein biosynthesis
What is the principle virulence factor for Haemophilus?
Polysaccharide capsule
For Haemophilus,
Typeable: _____
Non-typeable: ______
encapsulated
unencapsulated
How many capsular serotypes and biotypes does H. influenzae have?
6 capsular serotypes (A-F)
8 Biotypes (I - VIII)
The polysaccharide capsule of H. influenzae is identified using _____ and _____
capsule stains and Quellung reaction
H. influenzae is tested for _______
beta-lactamase
What are the virulence factors of typeable H. influenzae?
Fimbriae, IgA proteases, Outer membrane proteins and LPS
Typeable H. influenzae is ______
antiphagocytic and anticomplementary
What is Typeable H. influenzae composed of?
Composed of sugar-alcohol phosphate (polyribosyl ribitol phosphate)
_________ detects the Hib capsular antigen
latex agglutination
It is the 2nd Prevalent etiologic agent after S. pneumoniae
NTHI
What bacteria causes pink eye, a very contagious conjunctivitis?
H. aegyptius
H. aegyptius resembles ____
H. influenzae biotype III
What is the agent of chancroid of ‘soft chancre’ (STD)?
H. ducreyi
H. ducreyi can be isolated using chocolate agar with ____
vancomycin
________factors are required in the culture medium of Haemophilus(fastidious)
X and V
All clinically significant Haemophilus require the V factor, except ____ and ____
H. ducreyi and H. aphrophilus
The preferred culture media for Haemophilus is ____________ blood agar to observe hemolysis
Rabbit or horse
Why is sheep’s blood not used as culture medium for haemophilus?
Due to presence of NADase which inactivates NAD (V factor)
S. aureus, S. pneumoniae, and Neisseria all produce _____
V factor
CAP: _______
Nairobi Biplate medium: H. ducreyi
H. aegyptius
Satellism is observed in an organism that secretes what substance?
NAD substance
X (hemin): synthesis of cytochrome C
V (NAD): ____-
oxidation-reduction process
How many stains of encapsulated H. influenzae is present?
6 serotypes
What are the virulence factors of H. influenzae?
Polysaccharide capsule, pili, adhesion proteins, LOS, IgA protease, Biofilms, Phase variation of oligosaccharides
Epiglottitis: Hib infection
Bronchopneumonia: ______
NTHi infection
TRUE OR FALSE: Encapsulated strains are more invasive than than nonencapsulated
True