Leptospira

Morphology

L.interrogans

•Gram Negative•Aerobic•The Leptospira appear tightly coiled, thin , flexible Spirochetes. •0.1-6 micron to 0.1-20 micron•One end or both appears bent forms a hook.•Actively motile by two periplasmic sub terminal flagella.•Seen best with dark field Microscopy.

Cultural characteristics Leptospira grows best under aerobic conditions at 280 C to 300 C best demonstrated in Semisolid agar mediaOptimal Media• Fletcher’s Media (semi-solid , serum enriched)• Stuart’s Media (liquid , serum enriched)• EMJH media (semi-synthetic) (liquid , albumin & tween enriched)•Modified Korthof’s Medium.Optimal growth after 1 – 2 weeksCheck growth after every 3 days.

Antigens & toxins All isolates of L.inttterogans from different parts of the

world are serologically related and exhibit cross reactions in serologic tests.

Overlapping of Antigens do occur in different species. Outer envelope contains large amount of Lipopolysaccharides ( LPS ) Antigenic structure varies from one strain to other. This variation forms the basis of serologic classification. Production of endotoxins have been reported. Hemolysin (serovars ballum, hardjo, pomona &etc) Cytotoxin protein (serovars pomona and copenhageni)  Phospholipase C activity (serovar canicola)

Resistance & Disinfection Sensitive to moist heat at 1210 C for a minimum of 15

minutes. Also killed by pasteurization. Disinfected by Detergents Formaldehyde 70% Ethanol Glutaraldehyde 1% Sodium Hypochlorite.

Pathogenesis Transmission Water Through cuts & abrasions on skin & mucous membrane Nose Conjunctiva Mouth Rarely by ingestion Incubation period 1-2 weeks

Exact pathogenic mechanism is still not clear. When multiples blood stream produces fever. May establish organ involvement in Kidney and Liver, May produce hemorrhage and necrosis in the tissues and

initiates dysfunction of these organs. Damage to vascular damage by cytotoxic protein Intravascular hemolysis by hemolysin Nephrosis , uremia & Death Signs Fever , anemia Conjunctivitis Icterus Meningitis Agalactia Uveitis myocarditis

Epidemiology Cases reported in Sub-continent , having world wide

distribution Leptospirosis causes several animal infections like canines ,

bovines , porcine & Equines. Most wide spread zoonotic infection in Nature & anthropontic

disease. Human infections are accidental associated with contamination

of water, other materials contaminated with excreta and animal flesh.

Animal carriers often excrete upto 100million Leptospirosis per ml of urine.

Certain occupational groups such as agriculture workers in rice and cane fields, veterinararians, miners and sever cleaners are potential victims.

Human Leptospirosis Leptospirosis, also known as canicola fever hemorrhagic jaundice infectious jaundice mud fever spirochetal jaundice swamp fever swineherd's disease caver's flu or sewerman's flu is a bacterial infection resulting from exposure to the Leptospira

interrogans bacterium. There is an acute form of human infection known as Weil's syndrome

(Weil's syndrome is a severe form of leptospirosis that causes a continuous fever, stupor, and a reduction in the blood's ability to clot, which leads to bleeding within tissues. Blood tests reveal anemia. By the third to sixth day, signs of kidney damage and liver injury appear. Kidney abnormalities may cause blood in the urine and painful urination. Liver injury tends to be mild and usually heals completely.

Bovine Leptospirosis Caused by serovar pomaona , hardjo , canicola and

icterohemorrhagiae. Causes infertility and abortions. Infection may be precipated by stress.Clinical signs: Fever. Diarrhea. Anemia. Ichterus. Hemoglobinuria. Acute infection cause abortion.

Canine Leptospirosis Caused by serovar canicola and icterohemorrhagiae. Clinical signs: Latent to severe infection Chronic progressive nephritis followed by acute canicola

infection. Death may occur. It has four forms.1. Hemorrhagic form.2. Icteric form.3. Uremic or sub acute form.4. The in apparent form. First 3 forms characterized by

depression ,anorexia,vomiting,diarhhea or constipation.1.

Equine Leptospirosis Caused by pomona. Infrequent disease of horses.Clinical signs: Usually mild or sub acute Fever Depression icterus. Occasionally abortion. Uveitis iridocylitis (moon blindness or periodic opthalmia).

Porcine Leptospirosis Caused by pomona andphosa rarely by

canicola ,grippotyphos and icterohemorrhagiae.

Clinical signs: Sub clinical or latent infection. Unthriftiness Abortion Fever icterus anemia. Metritis & meningoencephitis occasionally.

Diagnosis Urine examination by Dark-field microscopy. Microscopic agglutination test (MAT) Isolation , cultivation & Identification of organisms. Lab animals (Guinea pigs & Hamsters) Histopathology Flourescent Antibody Technique (FAT) ELISA Control Vaccination rodent control Avoid contact with contaminated water with urine Avoid Swimming in contaminated water Proper screening of pets

THANK YOUAny Ambiguity?????