Spirochetes---Mycoplasma Flashcards
Treponema pallidum
gram
shape
LPS?
Gram−
spirochete
no LPS
Treponema pallidum flagella/axial filament
flagella (3/pole) in an axial filament (between inner &outer membrane)
Treponema pallidum metabolism
microaerophile (never grown in culture: host-dependent metabolism)
Treponema pallidum transmission
fragile (only survive transmission without exposure):
sexual and congenital (placental) transmission in body fluids and mucous membranes
Treponema pallidum virulence
host response causes disease symptoms
Treponema pallidum virulence factors, what causes symptoms?
Ø membrane adhesins
Ø hyaluronidase
Ø antiphagocytic coat (fibronectin)
(host response causes symptoms)
Syphilis from?
new world to old world
Syphilis transmission
sexual or congential
syphilis localities
local
desimminated
gummas
local syphilis
infectious?
hard chancre/ulcer at site of infection; infectious
disseminated syphilis
infectious?
rash, aches; mucous membrane lesions
(“the great imitator”); infectious
gummas
can occur where?
infectious?
form in which stage of disease?
damage to blood vessels, eyes, CNS; insanity; not infectious
These form in tertiary syphilis granuloma lesion = inflammatory mass which can perforate, e.g. roof of mouth or any other tissues.
syphilis stages
primary
asymptomatic stage
secondary
possible tertiary
Primary syphilis:
2-6 weeks; chancre, which heals spontaneously, giving false sense of relief.
Asymptomatic period:
2-24 weeks
Secondary syphilis:
2-6 weeks; 50% of primary infections go on to secondary; symptoms typically resolve spontaneously (but recurrence in 25% with 1 yr)
Microbe persists for 2/3 of secondary infections, with 1/2 exhibiting tertiary syphilis
Tertiary syphilis presentation
diffuse, chronic inflammation
congenital syphilis
prevention
lethality
dental abnormalities
[completely preventable by penicillin treatment early in pregnancy!):
high lethality in-utero OR when initially born without symptoms: high lethality typical of young children (e.g. 2 yrs old) with facial and dental abnormalities like “Hutchinson’s incisors” and “mulberry molars”.
treatment of 1 and 2 syphilis, vax?
penicillin for 1º and 2º infections, which contain actively growing spirochetes
No vaccine
Borrelia
gram and shape
Gram−
spirochete
Borrelia burgdorferi causes what disease?
lyme disease
lyme disease cycle
zoonosis: caused by Ixodes sacpularis tick
most common in spring/summer as the females lay eggs that hatch into larvae
larvae attach to rodents and acquire B. burgdoferi> detatch and molt into nymphs that can transmit the bacteria to more rodents or to humans
Borrelia burgdorferi virulence factor
adhesion proteins
some species with antigenic variation
Borrelia burgdorferi transmission/ reservior
ticks
• reservoir: rodents, deer
lyme disease stages
local
disseminated
chronic
local lyme disease
Erythema migrans rash at bite, fever
disseminated lyme disease effects on nn and heart, time frame?
nerve paralysis with heart arrhythmia (2-8 wks)
chronic lyme disease
arthritis and CNS paralysis due to persistent immune response
(>6 months)
lyme disease vax?
none
Relapsing Fever of Borrelia spp.due to
Relapsing fever due to effective immune response to antigenic variation (small pathogen population maintained)
Borrelia spp of relapsing fever
where from?
B. recurrentis: from body louse of humans
B. miyamotoi: from soft shell tick from animals
Borrelia sp. treatment
penicillin
tetracyclines
ceftriaxone
Rickettsia gram
negative
Rickettsia
intra or extracellular?
escape?
result?
obligate intracellular parasite: entry into endothelial cells, escape into cytoplasm by phospholipase, slow proliferation, cell lysis and vascular hemorrhages (no laboratory culture)
Rickettsia Virulence Factors:
intracellular growth
rapid cell-to-cell spread (from cell projections by actin-rockets and through cell lysis)
rickettsia transmission
zoonosis:
• wood tick (including transovarian transmission from adult ticks into tick eggs)
• reservoir: wild rodents
Rocky Mountain spotted fever due to?
species involved?
CTL immune disease due to rickettsia
Rocky Mountain spotted fever disease presentation/ progression
dissemenation?
mortality without treatment?
- rash of extremities, then trunk
- hemorrhagic lesions (with disseminated vascular CTL lysis of endothelial cells) ► spots
- dissemination to heart, kidneys, etc ► shock, death (mortality = 20-40% if no treatment)
Rocky Mountain spotted fever vax
none
Rocky Mountain spotted fever treatment
doxy or flouraquinolones
Chlamydia trachomatis gram
negative
Chlamydia trachomatis agent of? commonality?
Agent of chlamydia
The most frequent sexually transmitted infection
Chlamydia trachomatis intra/extracellular?
Obligate intracellular parasite (no laboratory culture; “ATP”-parasite)
Chlamydia trachomatis peptdioglycan
no synthesis of this/ low LPS
what causes Chlamydia trachomatis disease symptoms
Inflammatory cytokines released from infected cells cause disease= damaging cell-mediated immune response in various tissues
Chlamydia trachomatis
different forms/bodies
cell infection/ spread
elementary body (stable, infectious) reticulate body (replicating, fragile, non-infectious)
EB: epithelial cell adhesion to microvilli ► RB in phagosomes (no fusion with
lysosomes) ► replication and division ► EB ► cell lysis / exocytosis
Chlamydial diseases caused by:
CMI response
Chlamydial gonorrheal-like sexual disease
caused by 8 serotypes
• Mucopurulent urethritis, cervicitis, salpingitis (fallopian tube infection)
• mobility by adhesion to sperm (► epididymitis prostatitis in men)
• PID (pelvic inflammatory disease) ► scarring ► ectopic pregnancy+ decreased fertility
other chlamydial diseases
3 serotypes: lymphogranuloma venereum
4 serotypes: trachoma (endemic chronic eye infection: blindness), ophthalmia neonatorum with conjunctivitis and pneumonia
treatment of chlamidyal diseases
- azithromycin: 1 dose
* tetracycline or erythromycin treatment
immune protection/ reinfection of chlamidya
no immune protection
reinfection: stronger CMI
C.pneumoniae strain causes
walking pneumonia
leading bacterial infection species
Chlamydia trachomatis
Mycoplasma pneumoniae gram
cell wall?
membrane?
non gram staining: (no rigid cell wall: no effect of
penicillin or lysozyme); strong membrane (due to sterols)
Mycoplasma pneumoniae sterilization
cannot be done with filtration (too small)
smallest prokaryote
Mycoplasma species are smallest prokaryote (M.
genitalium 580,070 bp – 475 genes)
Mycoplasma pneumoniae O2 use? preference for what tissue
strict aerobe (preference for bronchial mucosa)
Mycoplasma pneumoniae Virulence Factors:
Ø P1 adhesin for ciliated respiratory epithelium:
loss of ciliated cells: no mucus clearing from lungs
Ø slow growth
Mycoplasma pneumoniae disease
atypical, mild pneumonia, the leading cause in schools, students,
and military: aerosol transmission in crowded conditions
• often (>15%) combined with otitis media
Mycoplasma pneumoniae vax/ immunity
no vaccination; fading protective immunity after recovery
pneumonia species, which can be vaxxed against?
only pneumococcal can be vaxxed
