chapter 14: spirochetes Flashcards
describe spirochetes
- morphology
- culturing
- genera
how do they move
tiny, gram negative organisms with corkscrew configurations of various types
difficult to culture
3 genera
-treponema sp
borrelia sp
leptospira sp
move in spinning fashion via thin endoflagella called axial filaments
2 unique things about spirochetes
surroundd by additional phospholipid rich outer membrane with few exposed proteins (protects against immune system)
axial flagella come out of the ends of spirochete cell wall but run sideways (peripasmic flagella)
how do you test and screen for infections of spirochetes
darkfield microscopy
treponema pallidum causes
causes STD syphilis
primary stage of syphilis
painless chancre
secondary stage of syphillis
rash on palms and soles
condyloma latum
- painless wartlike lesion, occurs in warm moist sites like vulva or scrotum
- ulcerates and is extremely contagious
CNS eyes bones kidneys and joints may be involved
latent syphillis
25% may relapse and develop secondary stage symptoms again
tertiary stage
gummas of skin and bone
- localized granulomatous lesions which necrose and become fibrotic
- painless
cardriovascular (aortic aneurysm)
neurosyphillis
develops over 6-40 years
neurosyphillis 5 most common presentations
asymptomatic neurosyphilis (pt normal but CSF has syphilis + test result)
subacute meningitis: pt has fever, stiff neck, headache
-CSF has high lymphocyte count, high protein, low glucose
(most bacteria cause acute meningitis with high neut count and low glucose)
meningovascular symphilis: spirochetes attack blood vessels in brain and meninges
tabes dorsalis
posterior column and dorsal roots of spinal cord affected
-vibratory and proprioception
-loss of reflexes and loss of pain and temp sensations (dorsal root)
general paresis: mental deterioration and psychiatric symptoms
MAST G
-this G gets lucky often so it gets to his head (neurosyph) but he contracts syphillis from all the play
argyll-roberston pupil
may be present in both tabes dorsalis and general paresis
-accomadation without reaction to light
rule of sixes with syphillis
6 axial filaments
6 week incubation
6 weeks for ulcer to heal
6 weeks after ulcer heals, secondary syphilis develops
6 weeks for secondary syphilis to resolve
66% latent stage patients have resolution
6 years to develop tertirary syphilis
congenital syphilis
early congenital syphillis
late congenital syphillis
common presentation
early congenital syphilis: like severe adult secondary syphilis (widespread rash and condyloma latum)
- snuffles
- LN, liver, and spleen enlargement and bone infection common
late congenital syphilis
-similar to adult tertirary syphilis but cardiovascular involvment rare
- eight nerve deafness is common
- saddle nose
- saber shins (bowing of tibia)
- hutchinson’s teeth (upper central incisors widely spaced with central notch in each tooth)
- mulberry molars (molars have too many cusps)
how can you test active primary or secondary stages of syphillis
dark field microscopy
nonspecific treponemal tests
test for Abs against cardiolipin and lecithin
-VDRL and RPR
-nonspecific bc 1% of adults without syphilis will also have these Abs
specific treponemal tests
test for Abs against spirochete itself
FTA-ABS
all treponemal subspecies (often called non-venereal) tend to cause ___ and _____ except for ____ which primary manifestation is usually ___
skin ulcers, and gummas of skin
carateum causes skin discoloration
jarisch herxheimer phenomenon
pts with syphilis develop acute worsening of symptoms immediately after antibiotics are started
-killed organism releases pyrogen that causes symptoms
3 subspeces of treponema pallidum
-stages compared to syphilis causing trep
endemicum
pertenue
carateum
first two stages similar but unlike syphillis do not involve heart or CNS
endemicum
disease
where occurs
spread how
endemic syphlis, bejel
ocurs in desert zones of africa and middle east
shared by drinking and eating utensils
pertenue
disease
where occurs
spread how
symptoms
yaws
moist tropics
person to person contact with open ulcers
papule appears at initial site and grows over months becoming warlike mother yaw
tertiary lesions often cause significant disficguement of face
(imagine jaws taking bite of persons face)
disfiguring lesions on face destorying bone cart and ksin are called gangosa ( a gang of J(Y)aws)
carateum
skin disease limited to rural latin america
papule devlops which expands
secondary eruption of numerous red lesions that turn blue in the sun
within year lesion become depigmented turning white
borrelia
size, and viewed how
causes what disease
larger than treponema, view under light microscope with giemsa or wright stains
casuses lyme disease and relapsing fever
-both transmitted by insect vectors
Borrelia burgdorferi (lyme disease)
where found, resevoir and transmission
northeast, midwest, and northwest US
ixodes tick transferes borrelia burgdorferi
resevoir is white footed mouse and white tailed deer
-ticks pick up spirochete from these and can spread to humans
lyme disease early localized stage
skin lesion at site of tick bite (erythema chronicum migrans) ECM
-along with flulike illness and regional lymphadenopathy
