Lecture 6 Flashcards
What are the distinguishing features of Legionella?
Thing gram negative bacteria that maybe polymorphic
- its thin due to the thin peptidoglycan layer
- Has highly hydrophobic LPS on the outisde
- Flagella
- fastedious growth requirments
What the ecology of legionella? Whats the source of infection?
-Bodies of water especially polluted and mud; plumbing
- Biofilms found in nature
- persistent and adaptive
The source of infection for legionella is enviroment not person to person
How can legionella transmitted?
Transmission via mist aerosols.
-Home plumbing, hospitals and other buildings
What is the mechanism of legionella pathogenisis?
- Distal Airways
- PAMS=> amplified
- Causes bronchitis and inflamation
- Immunity is cell mediated
Whats the clinical manifestations of Legionella?
it results to pneumonia;
- Often compromised
- Transplant patients
- smokers
Leads to pontic fever: mild fibrill illness l no respiratory complains
How to diagnosis legionella?
Direct examination
- Stains poorly on gram safrenin
- DFA direct fluoresent antibody
What are the distinguishing features of legionella cultures?
- Grows on MaConkey Agar
- Non-enteric Growth bacteria
-Legionella grows on buffered charcoal yeast extract that has to be specially requested
Legionella can be diagnosed via different tools but not as helpful; what are 3 of them?
- Urinary antigen is 99% likely to be accurate but 40-80% sensitive.
- PCR uncertain value at present
- Seroloy is not good for acute stages
How to treat and control legionella?
Use of specific antibiotics
- Fluoroquinolones
- Macrolides (azithomycin
And maintain it via
-Superheating
-fixing water systems
aquatic devices maintenance
What are the characterisitcs of Mycoplasma?
Mycoplasma pneumoniae is a gram negative bacteria without cell wall. Historically known as the eaton disease.
-Mycoplasma can be a genital related bacterium (e.g Mycoplama genitalium)
Whats the morphology and growth of mycoplasma? and What type of antigens it has?
-Filamentous and requires yeast extract/serum
Antigens:
- Single serogroup
- P1 protein mediated attachment
What is the epidmiology of mycoplasma?
Endemic and epidemic.
- in schools and barracks
- Slow spread and requires contact.
Whats the pathogenisis of mycoplasma?
- requires mucosal attachment
- Nondestructive
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Whats the manifestation of mycoplasma?
- Pharyngitis
- trachebronchitis
- otitis media
- penoumonia
- generally mild (walking pneumonia
How to diagnose mycoplasma?How to treat mycoplasma
- Serology will have high IgM 1-3 weeks or paird with IgG.
-NO CELL wall so cell wall agent antibiotics cant work
So macrolids and tereacycline
What are the chalmydia organisms
1) chlamyidia trachomatis
- chamydophila penumoniae
- chlamydophilla psittaci
Why are chlamydia considered bridge organisms?
Coz they have characterisitcs of bacteria and Viruses/
- Like viruses theyre obligate intracellular parasites (cannot generate ATP
- Like bacteria- DNA/RNA cell wall, antibiotic suceptible
What is the chlamydia life cycle?
Extracellulary theyre elementary body that go into the cell then they starte to replicate and become reticulate bodies.
Elementary bodies are considered infectious
Chlamydia immunity and Prescription?
They have group specific LPS but have serological variabilty
-Treatment uses cell wall agents, macrolides, tetracyclines and fluorquinolones
How to diagnose chlamydia?
Culture in cells
-Histology -fluids scraping and tissues
Use NAAT PCR -Swab, urine
Serology is not good for accurate diagnosis
What are the epidmylogical manifestations of chlamydia trachomatis?
Chlamyidia is a human pathogen; STD
Reinfection of chlamyidia is common.
SEROTYPE for chlamydia trachomatis’ D-K genital diseases
.
Persistance and cycling
it can lead to cell destruction for example fallopian tube inflammation
Chlamydia penumoniae facts?
Single serotype (TWAR) similar in manifestation to mycoplasma pneumoniae.
-Spread by large droplets
MIld slow onset. can reoccure.
What is chlaydophila psittaci?
Cna be caused by any bird or bird tissue dropings or shits.
Can develop due to bird contact or illegal exotoxins
Pathogenisis of C.Psittaci?
Inhalation then to liver and spleen and then seed int he lungs
Causes sytemic disease
-serology is useful here
