Lc 14 Flashcards
Explain the structure of spiroshetes
-Corkscrew shaped
-family leprospira has hooked ends
-flagella inside the outermembrane(periplasmic flagella )
What are the four pathogens of spirochetes?
Treponema, borrelia, leptospira, borreliella
Treponema is genetically monomorphic organism.what does monomorphic mean?
Different genomes of treponema is 99.9% similar.
Explain what kind of infection syphilis is and it early and late manifestation
STP, early : involve skin
Late: all organs and tissue sites, and central nervous system
What is main habitat of syphilis and is it able to do metabolism by itself?
Human, no it highly depends on host cells—> they cannot make fatty acids, nucleotides, amino acids by themselves.
Syphilis is highly invasive. How does it transmit throughout the body?
Gain access to blood and disseminates throughout body, and CNS.
Also, cross placenta and cause congenital syphilis
How do syphilis persist in human body?
Antigenic variation
Does infection get eradicated systemically?
No, it causes lifelong , chronic infection in untreated persons
What are some bacterial antigens?
LPS, peptidoglycan, bacterial cell wall
How could syphilis be a chronic infection? What is their method?
They change their antigens (antigenic variations) through gene conversion. They have TprK which has 7 variable regions for gene conversion.
How do we treat syphilis?
First line: penicillin
Alternatives : doxycycline, tetracycline, amoxicillin
Macrolides no longer used bc it resistance
How do we identify syphilis(treponema pallidum)?
Dark field microscopy, serologic testing(checks for the presence of antibodies)
What kind of disease does B.hermsii cause?
Relapsing fever
How do people get borrelia?
.
They get tick or Lise bites
Name diff. Types of borrelia according to their original of infection
Borrelia recurrentis: louse borne
Borrelia hermsii, turicatae, duttoni, crocidurae: tick borne
What are the reservoir and method of transmission of tick and louse respectively?
Tick: squirrels or small rodents, tick saliva/feces
Louse: human to human transmission. No known animal reservoir, hemolymph/feces
How do pathogenesis of B.hermsii work?
They change their surface proteins so that antibodies cannot recognize them but as the number of diff type of spirochetes are made, different antibodies corresponding to that spirochetes are also made so eventually the infection is cleared.
Particular vsp alleles has been associated with ___
CNS localization
What genes contribute to pathogenesis of B.hermsii
Vlp and vsp genes that are on a linear plasmid
Borrelia hermsii are very invasive in humans and what do they infect?
Borrelia hermsii invades blood stream
Many tissues and organ systems,including central nervous system
How do we diagnose &treat B.hermsii?
PCR,
Penicillins,tetracyclines
What disease does Borrelia burgdorferi cause?
Lyme disease
What kind of surface proteins are in high heterogeneity in B.burgdorferi?
OspA, OspB, OspC
What are B.burgdorferi’s habitat?
Small rodents, and they are transmitted to humans by tick bites
How does lyme disease get transmitted?
By regional ixodes tick species(hard ticks)
How does lyme disease get transmitted ?
By bite of nymph, infected ticks
Tick saliva injected into skin
Explain pathogenesis of lyme disease
Organism is very invasive, and reaches blood stream and dissseminates to many organs including CNS
What are the critical symptoms of lyme disease?
Erythema chronium migrnas(rashes) ans secondary lesions
Neurologic and cardiac abnormalities( headache, stiff neck, conjunctivitis, muscle pain,
Arthritis((swelling of joints) —> chronic
How do we diagnose lyme disease?
Physical exam for Ecm lesion or tick bites
Biopsy: id of organism by culture
PCR
How do we treat lyme diseae?
Penicillin, ceftriaxone, tetracyclines
What is the bacteria that live in the free living water or urban slum?
Leptospirosis
What is leptospirosis reservoir?
Animal reservoir!(domestic and wild animals)
How do leptospirosis transmit disease?
-Source of infection: water contaminated with infected urine of carried animals
-entry to skin
Explain leptospirosis pathogenesis?
Invasive!
Infect multiple organs including CMS
What is the outcome of leptospiral infection
Top: complex, multi system disease (aseptic meningitis, renal failure, jaundice, myocarditis, pulmonary hemorrhage, refractory shock
Middle: undifferentiated fever
Bottom: inapparent infection
What are the clinal courses of leptospirosis?
Sudden fever, headache,bacteia present in blood
How do we diagnose leptospirosis?
PCR, Serology
Penicillin,doxycycline, erythromycin
Low mortality rate
Is spirochete gram negative
Yes
