Spirochetes Gramnegative helical shape chemoheterotrophic alcohols, fatty acids, sugars, amino acids

1
Spirochetes Gram-negative helical
shape chemoheterotrophic - alcohols, fatty
acids, sugars, amino acids, covered with
sheath flagella - under sheath may wrap
around cell aerobic to anaerobic habitats mud
to human mouth Treponema Borelia
Leptospira Helicobacter
2
Borelia microaerophile flagella - form fibril
under sheath complex nutritional requirements -
hard to grow in lab pathogens for birds and
mammals (antigens change rapidly) vector
transmission - ticks, lice louse
scratching crushes louse bacteria
released enter abraded area or bite area
tick injected during bite classification
based on arthropod vectors two major
diseases relapsing fever lyme disease
3
Relapsing fever generalized infection
incubation period - one week symptoms fever,
headache, muscle pain symptoms associated
with bacteria in blood (not known how bacteria
get into blood) lasts 4-10 days period of
no symptoms lasts 5-6 days
relapse tick-borne is less severe and has lower
mortality relapses decrease in
intensity may cause myocarditis mortality up to
40, especially if untreated
4
Endemic Relapsing Fever tick-borne - occurs
whenever humans are exposed to ticks tick
tissues invaded by bacteria female
transmits to eggs young born infected tick bite
transmits to human Epidemic Relapsing Fever
louse-borne - rapidly disseminated when
overcrowding and poor hygiene are prevalent
natural disasters, war depends upon
multiplication and transfer of lice
5
Lyme disease - Borelia burgdorferi transmitted
by Ixodes or deer tick nymph transmits in
summer, female in early spring fall
minimum feeding time for transmission
3 days for nymphs 4 days for adults

nymph
6
Lyme disease - Borelia burgdorferi bulls-eye
rash - erythema migrans only in 80 first
stage fever, fatigue, headache, muscle joint
pain serologic tests best, but early tests may
be negative bacteria in skin, spread outward -
ring second stage flu-like symptoms fever,
chills, stiffness neurological symptoms in 5-10
of cases facial muscle droop,
meningitis-like symptoms heart damage may occur
in 5-10 of cases bacteria in blood stream,
enter tissues third stage months to years
after infection joint inflammation,
arthritis-like symptoms knee and elbow
esp. may be more serious neurological problems
paralysis, dementia may be autoimmune
response
7
Virulence factors not known recent
isolate Immune response slower than for other
infections antibodies to flagella react with
heart and muscle tissue antibodies to bacterial
cell associated with chronic arthritis
symptoms Treatment antibiotics must be started
early reduce permanent damage Prevention pr
otect against ticks protective clothing,
insecticides reduce rodent population
8
Treponema Gram-negative have an outer membrane
LPS not clearly shown motile microaerophilic to
anaerobic variety of carbon energy sources
carbohydrates, amino acids (pathogens not
cultivated in the lab) some require fatty acids
found in the oral cavity, intestinal tract,
genital areas of man and some animals
9
T. carateum pinta or carate - contagious least
invasive cutaneous infections T. pallidum subsp
partenue yaws - contagious intermediate in
invasiveness destructive lesions in bone and
soft tissue T. pallidum subsp pallidum syphilis
most invasive lesions in any tissue in the
body can cross blood vessel walls, placenta
10
Virulence factors no toxins known damage may be
due to inflammatory response release of
cytokines antigen-antibody complexes
trigger Syphilis three stages primary,
secondary and tertiary
11
Primary syphilis incubation period - 10-90
days lesion at the site of inoculation - chancre
(hard chancre) lesion not
infectious lesion spontaneously disappears in
2-6 weeks bacteria enter blood stream
asymptomatic period 2-24 weeks
12
Secondary syphilis fever and rash (not all
cases), swollen lymph nodes rash initially
on palms and soles rash on mucous
membranes, sores elsewhere due (probably) to
inflammatory response bacteria in
rash bacteria leave blood and enter tissues
heart, muscle, central nervous system latency
years
13
Tertiary syphilis symptoms develop over years
heart damage serious fatigue
disfiguring lesions - gumma neurological
symptoms neurological problems
dementia stroke
blindness Congenital syphilis symptoms vary with
age Treatment penicillin - early!
14
Helicobacter pylori Old ulcer treatment
drugs to reduce gastric acidity diet to
reduce irritation short term solution - not
a cure! long-term commitment bland diet
for life! expensive Bacterial cause
discovery great news antibacterial
treatment short term, less expensive Many with
bacterium, no ulcers why?? animal
models now available 10 of ulcers not caused by
bacteria causes aspirin, NSAIDs,
autoimmune disease
15
Helicobacter pylori Gram-negative helical
cells motile microaerophile carbohydrates not
utilized found in reproductive organs,
intestinal tract, oral cavity of man and
animals Campylobacter closely related group
16
Virulence factors adhesins - several which bind
cell surface components role not clear LPS
- causes inflammation cytotoxin - causes cells
to die inflammation urease - produces ammonia
which neutralizes acid ammonia toxicity to
stomach cells may contribute Source of
organism developed countries - uncommon in
children by age 50, 50 colonized developin
g countries - common even in children
17
Disease - proposed to survive, organisms quickly
enter mucous layer bacteria attach to tissues
produce ammonia LPS triggers
inflammatory response cytotoxin kills
cells other proteins trigger T-cell attack
on stomach cells inflammatory response may
clear the bacteria if not - 2nd
stage T-suppressors cant control inflammatory
response progressive mucosal damage
occurs enhanced inflammatory response
ULCER
18
Treatment two antibiotics Bismuth
Bismuth reduces inflammation and promotes
healing antibiotics reduce bacterial
population bacteria can survive in the mucous
layer two antibiotics, twelve weeks side-effect
diarrhea - disruption of normal flora