1. Zoonotic infection. Causative agents of the plague, tularemia, brucellosis and anthrax. Laboratory diagnostics and prophylaxis of diseases.
Vinnitsa National Pirogov Memorial Medical University / Department of microbiology

2. Taxonomy and classification
Pathogenic Yersinia
Taxonomy and classification
Family: Enterobacteriaceae
Genus: Yersinia
Medical important species:
Y.pestis
Y. pseudotuberculosis
Y.enterocolitica

3. Yersinia pestis

4. Cultivation
It is facultative anaerobe, and can grow at wide range of pH (4-10) and temperature (2-450C) Ordinary nutrient media (MPA and MPB) Selective media with hemolyzed blood

5. Antigen structure and virulent factors
Fraction I (F-I) antigen
V and W antigens
Virulent enzymes
Plague toxins

6. Epidemiology of the plague
Source of infection is wild or domestic rodents
The major route of transmission:
By biting of infected fleas
By skinning and handling of carcasses of infected wild animals
By inhalation of the dried flea feces or respiratory droplets from person with pneumonic form
By drinking of polluted water

7. Pathogenesis of the plague
Major clinical forms :
Bubonic form
Pneumonic form
Enteric form
Septicemia

8. Bubonic form of plague

9. Laboratory diagnostics
Microscopy
Culture method
Biological method

10. Prevention and therapy
Specific prevention: Chemoprophylaxis

11. Other Yersinia
Y. pseudotuberculosis Feature of morphology: polymorphic gram-negative rods, motile at 220C and non-motile at 370C Features of cultivation: it grows slowly and scanty onto the solid media (MPA, MacConkey agar) with formation R or S-colony Biochemical features: it is H2S (-), urease (+) and rhamnose (+)

13. Epidemiology and pathogenesis
The source of infection is infected rodent.
Humans may be infected by ingestion of contaminated row vegetables or by drinking of contaminated water.
Clinical forms of pseudotuberculosis:
Fatal typhoid like illness with hepatosplenomegaly and purpura (generalized form)
Mesenteric lymphadenitis simulating acute appendicitis (local form)

14. Y.enterocolitica Clinical forms:
Self-limited gastroenteritis or enterocolitis (young children)
Mesenteric adenitis and terminal ileitis (older children)
Systemic disease with bacteremia, meningitidis, arthralgia or erythema nodosum (adults)

15. Laboratory diagnostics
Culture method
Serology

16. Francisella tularensis
Taxonomy and classification: Family: Brucellaceae Genes: Francisella Species: F.tularensis Biovars : type A – tularensis (non-arctic or American type; high virulent) type B – palearctika (European and Asian type; low virulent)

17. Francisella tularensis

18. Cultivation
It is obligate aerobe, nutritionally exacting and slowly growing bacteria
Fransis blood agar with dextrose and cystine
Yolk blood agar

19. Virulent factors
Capsule
Vi-antigen
Endotoxin
Allergens

20. Epidemiology
Reservoirs: wild rodents, squirrels, hedgehogs, and rabbits (source of infection).
Human may be infected by:
Biting of infected ticks
Direct contact with infected animal
Ingestion of contaminated food or water
Inhalation of infective aerosols or dried feces

21. Pathogenesis and immunity
Clinical forms:
Skin-bubonic form
Anginose form
Pneumonic form
Enteric form
Septic form

22. Bubonic form of tularemia

23. Laboratory diagnostics
skin allergic test
Serology.
Experimental infection.
Prevention : specific

24. Brucella
Taxonomy: Family: Brucellaceae Genus: Brucella Medical important species: B. melitensis B. abortus B. suis

25. Morphology

26. Cultivation and cultural properties
Brucella are strict aerobs, but B. abortus is capnophilic (it requires 5-10% of CO2 for propagation )
The media for cultivation of Brucella:
Liver infusion media (broth and agar);
Serum potato infusion agar
Serum dextrose agar with addition of polymyxin, bacitracin and cycloheximide

27. Epidemiology
The source of infection is infected domestic animal (cattle, goats, sheep, pigs)
The human may be infected by:
Ingestion
Direct contact
Inhalation

28. Pathogenesis Human infection may be three types: Latent infection;
Acute or subacute brucellosis
Chronic brucellosis

29. Enlarged lymph nodes at brucellosis

30. Laboratory diagnose
Culture method
Serology

31. Bacillus anthracis
Taxonomy Family: Bacillaceae Genus: Bacillus Medical important species: B. anthracis

32. B.anthracis

33. Cultivation
It is aerobe and facultative anaerobe and easily cultivated onto the ordinary nutrient media
Nutrient media:
Nutrient agar
Blood agar
Gelatin stab culture (“inverted fir tree”)
Penicillin media (“string of pearles”)

34. Antigen structure and virulent factors
Capsular antigen
Cell wall antigen
Somatic antigen
Exotoxin:oedema factor (OF), protective antigen (PA) and lethal factor (LF).

35. Epidemiology
The source of infection is ill animal (cattle, sheep, horses, and swine).
Human may be infected by:
Direct contact
Inhalation
Ingestion

36. Pathogenesis Cutaneous form Pulmonary anthrax Intestinal anthrax
Septicemia

38. Cutaneous form of anthrax

39. Laboratory diagnostics
Microscopy
Culture method
Experimental infection
Allergic skin test
Ascoli`s thermoprecipitin test

40. Prevention
Animals and human are protected by active immunization