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
• classification
non-pathogenic spirochete
Leptospira
pathogenic spirochete
Treponema
Borrelia
Leptospira
1 Taxonomy
2 Biological properties
3 Epidemicology
4 Pathogenicity and Immunity
5 Microbiological detection
6 Treatment and preventation
Order: Spirochaetales
Family: Leptospiraceae
Genus: Leptospira
•
L.interrogans
L.biflexa
pathogenic
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
contraction 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
Ag
serogroup-specific Ag
serovar-specific Ag
Resistance
• weak
• 60℃ ,1min,died
• exist in water or moist soil for severa
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 animals
Transmitted through breaks in the skin or intact
mucus membranes
Indirect contact (soil, water, feed) with infected
urine from an animal with leptospiruria
Occupational disease of animal handling
Epidemicology
Zoonoses
Invasiveness
• mechanism:adhension
endocytosis
endosome
inducing apoptosis or necrosis
Pathogenic substance:
• Endotoxin-like component(ELS)---cause
fever,inflammation,necrosis(lower
toxicity)
• Hemolysin---lysis RBC
• Cytotoxicity factor---muscle spasm and
dyspnea
• Cytopathogenic effect
substance(sensitive to heat ,50℃,30min;sensitive to
Route of infection
organism infected animal discharge
urine
contaminant water/soil
human
skin
blood stream
leptospirosis
recovery 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 diagnosis
Dark-field microscopy
Fontana silver stain--brown
Animal test
PCR
Serology
MAT
TR/patoc(IgM)
Indirect agglutination test
Treatment
• penicillin,tetracycline,streptomycin
• erythromycin(in large enough doses
early in the infection)
• 赫氏反应---chill,fever,hypotension and
even twitch ,shock,breath and
heartbeat pause.
Prevention
• rodent control
• vaccination of domestic animal