Difference between revisions of "Category:Leptospiraceae"

Leptospira

• Motile, helical bacteria found in aquatic environments
• Require liquid media for culture
• Cause leptospirosis in all animals, which can range from mild urogenital tract infections to systemic diseases
• Organisms persist in kidney tubules or genital tract of carrier animals and are shed in urine
• Transmission via direct contact
• Serovars are fairly host-specific, causing mild disease in the maintenance host, with shedding in the urine
• Maintenance hosts may transmit the infection to incidental hosts, which are less susceptible to infection, but develop serious disease
• May cause severe systemic disease, resulting in enteritis

• Pathogenesis and pathogenicity
  • Depends on virulence of the serovar and susceptibility of the host
  • Leptospires invade tissues through moist skin or via mucous membranes, aided by their motility
  • Leptospires may invade via receptor-mediated endocytosis
  • They disseminate through the body via the blood stream
  • Antibodies clear organisms from the blood stream after about 10 days of infection
  • Organisms may persist in the renal tubules, uterus, eye or meninges
  • Evade phagocytosis possibly via macrophage apoptosis
  • Damage red blood cell membranes and endothelial and liver cells, leading to haemolytic anaemia, jaundice, haemoglobin pigmentation, haemoglobinuria and haemorrhage in acute leptospirosis

• Diagnosis
  • Clinical signs and history of exposure
  • Dark-field microscopy of urine may detect organisms
  • Isolation from blood or urine by culture or animal inoculation
  • Identificaiton or certain serovars using DNA probes and serology
  • FLuorescent antibody technique for identification in tissues
  • Silver impregnation
  • Molecular techniques such as PCR
  • Serology using microscopic agglutination test or ELISA