L.interrogans is a gram-negative, aerobic spirochete bacterium that causes leptospirosis. It appears as tightly coiled, thin, and flexible spirals under microscopy. It grows best aerobically at 28-30°C in enriched semisolid or liquid media like Fletcher's Media or EMJH media. L.interrogans strains from different parts of the world are serologically related but can vary antigenically, forming the basis for serological classification. Leptospirosis is a zoonotic bacterial infection spread via contact with water or soil contaminated by animal urine and it can cause fever, jaundice, kidney damage, and liver failure in its most severe

2. 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.

3. Leptospira grows best under aerobic
conditions at 280 C to 300 C best
demonstrated in Semisolid agar media
Optimal 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 weeks
Check growth after every 3 days.

4.  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)

5.  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.

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

7.  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

8.  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.

9.  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.

10.  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.

11.  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.

12.  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).

13.  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.

14.  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

15. THANK YOU
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