chapter 24chapter 24

spirochetesspirochetes

chapter 24chapter 24

spirochetesspirochetes

thin-walled, flexible, spiral rodsthin-walled, flexible, spiral rods

motile through the undulation of axial motile through the undulation of axial filamentsfilaments

Cause disease in humanCause disease in human Treponema : Treponema : Leptospira :Leptospira : Borrelia:Borrelia:

Histology: Histology: Treponema pallidumTreponema pallidum - testis infected rabbit- testis infected rabbit

Treponema pallidum

• transmissiontransmission – genitalgenital– placentaplacenta

0.1-0.2 x 6-15um; 8-14 small, regular spirals

syphilissyphilis

characteristics

spirochetesspirochetes not seen on Gram-stained smearnot seen on Gram-stained smear seen only by darkfield microscopy, seen only by darkfield microscopy, silver isilver i

mpregnationmpregnation or immunofluorescence or immunofluorescence not cultured in vitronot cultured in vitro

habitat and transmissionhabitat and transmission

habitat: the human skin or mucous habitat: the human skin or mucous membranes membranes

intimate contactintimate contacttransmission transmission from mother to fetus from mother to fetus across the placenta across the placenta

　　　　　　　　PathogenesisPathogenesis

Produce no important toxins or emzymes Produce no important toxins or emzymes

multiplies at site of inoculationmultiplies at site of inoculation spread widely via the blood streamspread widely via the blood stream

Early syphilisEarly syphilis

Primary syphilisPrimary syphilis: 2-10 weeks, local, nonte: 2-10 weeks, local, nontender ulcer (chancre)nder ulcer (chancre)

Secondary lesionsSecondary lesions: maculopapular rash : maculopapular rash or moist papulesor moist papules

rich in spirochetes and highly infectiousrich in spirochetes and highly infectious

1st & 2nd lesions heal spontaneously1st & 2nd lesions heal spontaneously

some remain latentsome remain latent

II

IIIIIIIIII

Tertiary syphilis (late phase)Tertiary syphilis (late phase)

Gummas Gummas 树胶肿树胶肿 , aortitis, aortitis 主动脉炎主动脉炎 , centr, central nervous system involvement, cardiovaal nervous system involvement, cardiovascular lesions scular lesions

Treponemas are rarely seen, Treponemas are rarely seen, noninfectiononinfectiousus

Congenitial syphilisCongenitial syphilis

Infected woman fetusInfected woman fetus

StillbirthStillbirth

Multiple fetal abnormalities Multiple fetal abnormalities

Treatment Treatment

Penicillin is effective in the treatment of Penicillin is effective in the treatment of

all stagesall stages

Leptospira interrogansLeptospira interrogans

DiseaseDisease

leptospirosisleptospirosis

Leptospira

characteristics

tightly coiled, fine spirochetetightly coiled, fine spirochete Not stained, can be seen on Not stained, can be seen on dark-field dark-field

microscopymicroscopy Grow in bacteriologic media containing Grow in bacteriologic media containing

serum serum (Korthoff media)(Korthoff media)

Habitat and transmissionHabitat and transmission

habitat: rats, domestic livestockhabitat: rats, domestic livestock

transmission: via animal urine----transmission: via animal urine----contaminate water and soilcontaminate water and soil

(human contact contaminated (human contact contaminated environment)environment)

pathogenesispathogenesis

High risk population: peasant, person whHigh risk population: peasant, person who fight a flood, or fishingo fight a flood, or fishing

Ingested or Ingested or pass through mucous membrpass through mucous membranes or skinanes or skin

Circulate in the bloodCirculate in the blood Multiply in various organsMultiply in various organs

Clinical findingsClinical findings

Initial bacteremic phase: fever, chills and intense Initial bacteremic phase: fever, chills and intense headacheheadache

(conjunctivae congestion, pain of gastrocnemius,(conjunctivae congestion, pain of gastrocnemius,

lymphadenectasis)lymphadenectasis)

Subsequent immunopathologic phase: Subsequent immunopathologic phase: meningitimeningitiss (stiff neck), (stiff neck), liver damage liver damage (jaundice)(jaundice) and impair and impaired kidney functioned kidney function

diagnosisdiagnosis

History of possible exposureHistory of possible exposure Suggestive clinical signsSuggestive clinical signs Detect AbDetect Ab Isolation of leptospirasIsolation of leptospiras

TreatmentTreatment

Penicillin GPenicillin G

avoid contact with the contaminated avoid contact with the contaminated environmentenvironment

vaccination of livestock and petsvaccination of livestock and pets rat controlrat control

preventionprevention