LEPTOSPIRA(Leptospira interrogans)

Leptospira is a genus of spirochaete bacteria,which includes a small pathogenic and saprophytic species.

Observed in 1907 in kidney tissues

Taxonomy : The genus Leptospira is divided into 20 species based on DNA

hybridization studies.

Pathogenic Leptospira kirschneriLeptospira noguchiiLeptospira alexanderi

Non-pathogenic Leptospira biflexaLeptospira meyeriLeptospira wolbachii Intermediates Leptospira faineiLeptospira broomii Leptospira wolffii

Domain : Bacteria

Phylum : spirochaetes Class : spirochaetes

Order : spirochaetales

Family : Leptospiraceae

Genus : Leptospira

Scientific classification:

Weil’s syndrome, mud fever, autumn fever, hemorrhagic syndrome, cane cutter’s fever , Stuttgart fever, canicola fever

Other names :

Structure : has endoflagellumOuter envelopeCytoplasmic cylinder

Morphology : tightly coiled spiralLong as 6-12 μm0.1μm in diameterHooked in one or at both endsMotileSilver staining (brown)

General characteristics:

Aerobic flat colonies28º- 30º c7.2 - 7.4Resistance:Weak60º c for 1minExist in water, moist soilSensitive to penicillin

Culture:

Mainly a zoonotic disease: transmitted to humans by animals

Through breaks in the skin, or by mucous membrane

Indirect contact : soil , water , feed with infected urine from an animal with leptospiruria

Epidemiology :

Endotoxin- like components (ELS) causes fever , inflammation , necrosis (lower toxicity)

Hemolysin- lyses RBC

Cytotoxicity factor- muscle spasm and dyspnoea

Pathogenic substance:

adhesion »»»» endocytosis »»»» endosome »» »» inducing apoptosis or necrosis

Route of infection :Organism »»» infected animal discharge urine

»»» contaminant water/soil »»» human skin »»» blood stream »»» leptospirosis »»» recovery or fatality (30%)

Invasiveness : mechansim

Humoral immunity; after 2 weeks specific Ab can be examined

Specific Ab doesn’t act efficiently on kidney

They can multiply and excrete through urine

Immunity:

The symptoms of leptospirosis usually develop abruptly 7 to 14 days after exposure to the leptospira bacteria.

fever sudden headachesnausea and vomitingloss of appetitemuscle painconjunctivitis (irritation and redness of the eyes)cougha short-lived rash

Symptoms :

Penicillin G, tetracycline, streptomycin , erythromycin

Prevention: Rodent control Vaccination of domestic animal

Treatment: