spirochetes 04 口腔七年制. introduction monocellular organism, flexible, helical,possess an...
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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