Spirochetes

04 口腔七年制

卞媛

媛 高晓

丽 刘晓

东 邵琦 钱华 张雪 于洋 李盈

凯 宋洪宁

Introduction

• monocellular organism, flexible, helical ,possess an axial filament (active motile)

• situs is between baterium and protozoa

• Gram-negative

Introduction Fontana silver stain

sensitive to antibiotics(penicillin etc.)

Introduction

• classificationnon-pathogenic spirochete

pathogenic spirochete

Leptospira

Treponema

Borrelia

Leptospira

1 Taxonomy2 Biological properties3 Epidemicology4 Pathogenicity and Immunity5 Microbiological detection6 Treatment and preventation

Order: SpirochaetalesFamily: Leptospiraceae

Genus: Leptospira

• L.interrogans pathogenic

L.biflexa non-pathogenic

General structure• outer envelope

• endoflagellum(6 kinds of protein)

• cytoplasmic cylinder

Morphology• tightly coiled spiral,long(6-12μm)•hooked in one or both ends•active motility---rhythmic contracti

on of axial filament• silver staining--brown

LM Fontana

Culture• aerobic • Korthof substrate• transparent, unregular,flat colony• tempreture: 28℃ to 30℃• pH: 7.2 to 7.4

Genus-specific protein Ag

serogroup-specific Ag

serovar-specific Ag

Ag

Resistance • weak• 60℃ ,1min,died • exist in water or moist soil for several

months• sensitive to penicillin

Epidemicology

Mainly a zoonotic disease – Transmitted to humans from a variety of wild

and domesticated animal hosts– In USA most common reservoirs rodents

(rats), dogs, farm animals and wild animalsTransmitted through breaks in the skin or intact

mucus membranesIndirect contact (soil, water, feed) with infected

urine from an animal with leptospiruriaOccupational disease of animal handling

Epidemicology

Zoonoses

Invasiveness

• mechanism:adhension endocytosis

inducing apoptosis or necrosisendosome

Pathogenic substance:• Endotoxin-like component(ELS)----cause f

ever,inflammation,necrosis(lower toxicity)• Hemolysin---lysis RBC• Cytotoxicity factor---muscle spasm and dy

spnea• Cytopathogenic effect substance(sensi-tive to heat ,50℃,30min;sensitive to trypsin)

Route of infection

organism infected animal discharge urine

contaminant water/soil human skin

blood stream leptospirosisrecovery or fatality(30%)

Clinical type of diseases• Jaundice---hemorrhage type• Influenza---typhoid type• Pulmonary---hemorrhage type• Renal---failure type• Meningoencephalitis type

Immunity

• Humoral immunity;after 2 weeks,specific Ab can be examed

• Specific Ab doesn't act efficiently on Leptospira in kidney.

• So they can multiply in patient's kidney and excrete through urine

Specimen: the first week , blood. the second week, urine meninigoirratation,cerebrospinal fluid

Etiologic diagnosisDark-field microscopyFontana silver stain--brownAnimal testPCRSerologyMATTR/patoc(IgM)Indirect agglutination test

Treatment• penicillin,tetracycline,streptomycin • erythromycin(in large enough doses ear

ly in the infection)• 赫氏反应 ---chill,fever,hypotension and e

ven twitch ,shock,breath and heartbeat pause.

Prevention• rodent control• vaccination of domestic animal