Zoonotic disease-Bacillus anthracis,Rat bite fever (1).pdf

Zoonotic disease

1. ZOONOTIC DISEASES
Bacillus and Rat Bite Fever

2. Objectives
•Enumerate the microbial agent and their vectors causing Zoonotic
disease.
•Describe the morphology and cultural characteristics of Bacillus
•Discuss the mode of transmission, pathogenesis, C/F, laboratory
diagnosis and prevention of anthrax.
•Describe the characteristic feature of Bacillus cereus and their clinical
importance.
•Describe the characteristic feature of Streptobacillus moniliformis and
Spirillum minus and their clinical importance.

4. Zoonotic bacterial infections
Bacteria Animals
Anthrax Herbivores
Plague Rat
Brucellosis Sheep, goat, camel
Rat bite fever Rodents
Leptospirosis Rodents
Non-typhoidal salmonellosisPoultry
Bovinetuberculosis Cow
Endemic typhus Rodents
Tularaemia Rabbits
Viruses Animals
Rabies Dogs
Yellow fever Monkeys
Japanese B
encephalitis
Pigs
Kyasanurforest
disease
Monkeys
Chikungunya Monkeys
Monkey pox Monkeys
Prion diseasesCattle
Hemorrhagic feversRodents, cattle,
wild animals
Influenza Pigs, birds

5. Zoonotic Fungal infections
Fungi Animals
Zoophilicdermatophytoses
TrichophytonequinumHorse
Trichophytonsimii Dogs, poultry
Microsporumcanis Dogs
MicrosporumequinumHorse
Sporothrix Cats
Malassezia Dogs, cats
Cryptococcus Wide variety
ofanimals, birds
PenicilliummarneffeiBamboo rats
Fungi Animals
Histoplasma Cattle, sheep
Coccidioides Dogs
Paracoccidioides Dogs
Blastomyces Dogs
PneumocystisjiroveciiRodents

6. Zoonotic Parasitic infections
Parasites Animals
Toxoplasma Cats
Leishmania Dogs
Taenia Pigs, cattle
Echinococcus Dog
Cryptosporidium Cattle
Fasciolopsisbuski Pigs, cattle
Trichinella Pigs
Hookworms and Roundworms Dogs and cats
Dirofilariaand
zoonoticBrugiaspecies
Dogs, cats, raccoons, etc.

7. Why lab diagnosis is important?
•Treat them →containment
•Economic loss → outbreak in
animals
•History regarding occupation and
duration of exposure to animals

Lab Diagnosis
•Specimen: according to site
•Microscopy
•Isolation
•Serology
•Molecular tests
National Vector Borne Disease
Control Program Case detection &
confirmation
Reporting &
outbreak
investigation
Case
management &
control measures

8. ANTHRAX
•Zoonotic disease - caused by spore-forming obligate aerobe -
Bacillusanthracis.
•1849-Pollender- First pathogenic bacteriumseen under microscope
•1876-Robert Koch- First bacterium to be isolated inpure culture
•1881-Louis Pasteur- Anthrax vaccine was thefirst live attenuated
bacterialvaccineprepared
Historical Importance

9. Bioterrorist weapon
Anthrax is a likely choice because:
•It occurs naturally, can be made in a lab, and lasts in its environment.
•It can be released quietly, without anyone knowing.
•Tiny spores could be put into powders, sprays, food, and water.
•You may not be able to see, smell, or taste the spores.
•It has been used as a weapon in the past. several countries have had active
anthrax bioweapons programs.
•In 2001, letters with powdered anthrax spores were mailed in the United
States, causing 22 infections, including 12 in mail handlers, and 5 deaths.

11. Virulence Factors and Pathogenesis
Anthrax Toxin
1.Protective antigen- Binding fragment. Binds to the host cell receptors
andfacilitates the entry of other fragments into the host cells.
2.Edemafactor- Active fragment - Acts as adenylyl cyclaseincreases
hostcellcAMP​
3.Lethal factor- Causes cell death - Acts by cleaving host cell MAPK.
•Toxin fragments arenot toxic individually, but in combination they
producelocaledemaand generalized shock.
•Loss of plasmid makes the strainavirulent(Basis of original anthrax
vaccineprepared by Pasteur)

13. Virulence Factors and
Pathogenesis
Anthrax Capsule
•Polypeptide capsule
(polyglutamate)
•Capsule is plasmid
(pX02) coded
•Inhibits complement
mediated phagocytosis

14. Clinical Manifestations -Animal Anthrax
•Anthrax is primarily azoonotic disease
•Animals affected– Herbivores -cattle, sheep and less often horses & pigs
•Acquiredby ingestion of spores present in soil. Direct spread from animal toanimal
is rare
•Presentation- fatalsepticemia​/localised cutaneous disease
•Infective materials- Discharges from mouth, nose & rectum. Bacillisporulatein soil

15. Clinical Manifestations -Human Anthrax
Transmission:
•Cutaneous mode—spores entering through the abraded skin
•Inhalation of spores
•Ingestion of carcasses of animals dying of anthrax containing spores
Clinical Types:
•1. Cutaneous anthrax
•2. Pulmonary anthrax
•3. Intestinal anthrax – rare, occurs due to ingestion of spores

17. Cutaneous anthrax
•IP 1-10 days
•Hide porter disease
•MOT – cutaneous exposure
through abraded skin
•Malignant pustule – papule -
painless vesicle – eschar
•Resolves spontaneously
•10-20% fatal septicemia

18. Pulmonary anthrax
•IP 1-6 days
•Wool sorter’s disease
•MOT – inhalation of spore
•Hemorrhagic pneumonia
•Most common form to cause
bioterrorism
•Due to ingestion of meat contaminated
•Severe enteritis with bloody diarrhoea
Intestinal anthrax

19. Epidemiology
•Incidence of human anthrax - highest -
Africa, and Central and Southern Asia.
Human anthrax cases may be of two
types:​
•1. Non-industrial cases: Result from
agricultural exposure to animals​
•2. Industrial cases: Result from
infected animal products such as
hides,hair, bristles and wools.

20. Laboratory diagnosis of Anthrax
•Specimen:Pus, sputum,blood, CSF​
Direct demonstration
•Gram staining: Gram-positive,
largerectangular bacilli, non-bulging spore.
Long chains of rectangular rod (Bamboo stick
appearance) spores are usually not seen in
clinical sample.
•McFadyean’sreaction: Showsamorphous
purple capsulesurrounding blue
bacilli(polychrome methylene bluestain)
•Direct IF: Detects capsular antigen​
•Ascoli’sthermoprecipitation test

21. Culture
•Nutrient agar: Medusa headappearance colonies​
•Blood agar: Dry wrinkled,nonhemolyticcolonies
•Gelatin stab agar: Inverted fir tree appearance growth​
•Selective media:​Solid medium with penicillin: String of pearl
appearance​; PLET medium.

22. Culture characteristics -
On N/A – Frosted glass appearance
Medusa
head
appearance-
colonies
under low
power
microscope
Inverted fir tree appearance

23. String of pearl appearance on
selective media
Selective media – solid media with
penicillin, PLET Media

24. Laboratory diagnosis
•Serology-
ascoli’s thermoprecipitin test.
•Antibodies detectionby ELISA
•Molecular test – PCR. :PCR usingusingBA pX01/02primers.

25. Cutaneous, pulmonary,intestinal

26. Prevention
•Disposal of animal carcasses by burning or by deep burial in lime pits
•Decontamination (usually by autoclaving) of animal products
•Protective clothing and gloves for handling potentially infectious materials.
Live Attenuated, Non-capsulated Spore Vaccine
•Commercially available - Stern vaccine.​
•Extensively used in animals.​Protective for 1 year following single injection.​Not
safe for human use.
Adsorbed (Alum Precipitated) Toxoid Vaccine
•Prepared from the protective antigen
•Safe & effective for human use​. Indicated forpre exposureand post exposure
prophylaxis

27. AnthracoidBacilli
•Bacillusspecies other than the anthrax bacillus -
calledanthracoidbacilli.​
•ExceptB. cereus -most of them - non-pathogenic - common
contaminants inlaboratorycultures​
•Produce dry wrinkled colonies and in smear - appear as chains of
spore-bearing gram-positivebacilli​
•They are motile, and hemolytic colonies on blood agar, etc.

28. Bacillus cereus
•Normal habitant of soil - widely isolated from food items - vegetables,
milk,cereals, spices, meat and poultry.
•Mainly causes food poisoning.​
•Can also cause ocular and various other systemic infections.

29. Bacillus (Spores) Used as Sterilization Control
•Geobacillusstearothermophilus(formerlyBacillusstearothermophilus)
- usedfor autoclave, hydrogen peroxide gas plasma sterilizer and
liquid acetic acidsterilizer​
•Bacillusatrophaeus- used for ethylene oxide sterilizer and dry heat
sterilizer.

30. Rat-bite fever (RBF)
•septic fever, petechial rashes, and painful polyarthritiswith frequent relapses.
•Streptobacillus . moniliformis-North America,
• Spirillum . minus: sodoku, Asia.
Transmission:
•present as normal flora in throat of rat.
•Transmitted by rat bite, contact with urine/bodily secretions​
•Consumption of food or water contaminated with the urine and droppings
ofrodents carrying the bacteria.

31. Haverhill feverorepidemic arthritic erythema
Streptobacillusmoniliformis: IP 3-20 days
Haverhill fever:1926 outbreak in Haverhill, Massachusetts, where the
disease was first reported.
In case of Streptobacillus, the lesions have mild inflammation and
lymphadenopathy is rare
•Gram-negative, irregular chain ,beaded, L -forms ,
•Pleomorphic, nonmotile
Isolated from blood, synovial fluid
and other infected tissues

32. Spirillum minus
Spirally coiled bacilli ,Gram negative
Motile with 1-7 amphitrichous bacilli
Stain – Giemsa stain, Fontana stain/Dark field
microscopy
In Spirillosis, IP two to ten days.
bite site is indurated and may ulcerate and
have lymphadenopathy .

33. •Penicillin G at a dose of 200,000 units every 4 hours or Ceftriaxone 1
gram intravenously daily.
•Duration of antibiotics is 2 weeks.
•In Penicillin allergic patients, Doxycycline 100 mg twice a day either
intravenously or orally can be substituted.
Complications
Endocarditis
Fulminant sepsis
Pneumonitis
Meningitis
Liver abscess
Adrenal gland failure
Petechial and purpuric lesions on the foot of a rat bite fever patient.

34. THANK YOU