GENUS LEPTOSPIRA

GENUS LEPTOSPIRA spirochete transverse fission Gram - motile helical spirochete transverse fission oxidase+ catalase+ obligate aerobe 1 axial filament long chain fatty acid as source of carbon ammonium salt as source of nitrogen * persist in renal tubule or genital tract of carrier (w/o clinical sign) * found in aquatic environment * organism survive in urine of carrier, food, pen, water are source of infection GENUS LEPTOSPIRA

Diagram of spirochaete cell. (1 Axial filament) (protoplasmic cylinder) Diagram of spirochaete cell.

(Internal flagella)

Cell of leptospira

Leptospira interrogans (pathogenic strains) Classification of the Genus Leptospira Leptospira interrogans (pathogenic strains) Leptospira biflexa (saprophytic strains) Serovar >60 L. biflexa, >200 L. interrogans > 250 serovars in 23 serogroups (1998)

Genomospecies of the Genus Leptospira Species classified by DNA homology 1 species L. borgpetersenii L. fainei L. inadai L. interrogans sensu stricto L. kirschneri L. Biflexa L. meyeri L. noguchii L. santarosai L. weilii L. alexanderi (1999) L. Wolbachii L. parva Little correlation between serologic type and genomospecies

Leptospirae. Disease characteristic Leptospirae Disease characteristic Domestic animals most commonly affected : dog : septicemia, hepatic & renal disease cattle and swine : septic illness in young animals, abortion horses : abortion and recurrent uveitis human : acute hemorrhagic disease, acute hepatitis with jaundice

* contact of mucous membrane or skin with urine contaminated material Transmission * contact of mucous membrane or skin with urine contaminated material * milk from acutely infected cows * genital excretion from cattle and swine Toxins * endotoxin * hemolysin

Pathogenesis. Relates to virulence of infecting serovar Pathogenesis Relates to virulence of infecting serovar and susceptibility of host species moist softened skin or mucous membrane blood stream maybe clear from circulation following appearance of antibodies (10 days) colonizing particularly liver & kidney others: muscles, eyes, meninges, uterus

hemorrhage, hemolytic anemia Pathogenesis (continue) degenerate changes damage vascular endothelium, RBC hemorrhage, hemolytic anemia 2ry change - liver damage, blood destruction icterus - renal tubule injury nephritis

Pathogenesis & Pathogenicity Organism through mucous membrane hematogenous proliferation spleen, kidney, liver fever, anemia, hemorrhage at submucosa and subserosa, conjunctivitis, icterus, nephrosis uremia last stage causes toxemia from liver, kidney and vascular endothelium damage

leptospirosis in animals Canine Leptospirosis L. canicola*, L. pomona, L. grippotyphosa etc. subacute or uremic form in apparent form L. icterohaemorrhagiae acute hemolytic anemia icteric, hepatic necrosis recovered dog sheds organism through urine for months L. bratislava, L. seijoe etc. *Host-adapted serovar

dog Multifocal necrosis in liver Multifocal hemorrhage in lung Multifocal interstitisl nephritis and renal tubule dog

Bovine Leptospirosis Swine Leptospirosis L. pomona, L. hardjo* fever, agalactia infertility, abortion, hemoglobinuria, icterus L. grippotyphosa, L. seijoe, L. icterohaemorrhagiae etc. Swine Leptospirosis L. pomona* in apparent form abortion at last stage infrequent metritis, icterus L. bratislava, L. tarassovi, L. icterohaemorrhagiae etc.

Multifocal interstitial nephritis

Leptospirosis in pig

Equine Leptospirosis Ovine Leptospirosis Immunity L. pomona, L. bratislava fever, icterus, abortion, stilbirth ophthalmitis, renal disease in young one L. hardjo* acute hemolytic anemia interstitial nephritis in lambs L. pomona hemolytic anemia, abortion in ewes generally solid after recovery & serovar specific Ovine Leptospirosis Immunity

Conjunctival suffusion icterus

Pulmonary haemorrhage (human leptospirosis)

Isolation & Identification 1). examine only fresh urine by dark field formalinized urine destroyed motility other body fluid need low - speed centrifugation 2). inoculate to guinea pig or hamster, from urine, blood, exudate, when bacteremia, the experimental animal’s blood is used for isolation, using specific antisera for serogrouping and serotyping The agent maybe isolated from blood during 7-10 days and from urine 2 wks after initial infection either by culture in liquid medium or by animal inoculation

Isolation & Identification 3). organisms may be demonstrated in kidney section with special stain 4). FA technique, identify Leptospira in tissues and urine sediment 5) serology - microplate agglutination live culture & test serum (paired serum) four – fold rise titre

Leptospira in tissue, silver stainning

Fluorescence antibody technique