This document discusses the genus Yersinia, focusing on important pathogenic species. It covers Yersinia pestis, the causative agent of plague, describing its isolation, transmission cycle involving rodents and fleas, clinical forms (bubonic, pneumonic, septicemic), diagnosis and treatment. It also briefly discusses Yersinia pseudotuberculosis and Yersinia enterocolitica, which can cause yersiniosis in humans and animals through contaminated food.
2. Yersinia
Important species :
Y.pestis:
Plague in man & rodent
Yersiniosis
Y.pseudotuberculosis
Pseudotuberculosis in animals
Y.enterocolitica
Enteritis in man & animal
5. No serotypes but biotypes
Biotypes Nitrate
reduction
Glycerol
fermentation
Pandemic
associated
Y. pestis var
antiqua
+ + 1st -Justinian
(AD 541)
Roman Emperor
Justinian
Y. pestis var
medievalis
- + 2nd –Black
Death –Europe
(1347-52)
Killed 1/3rd
population
Y. pestis var
orientalis
+ - 3rd- Hong Kong,
China, India
(1894-1918)
10 million deaths
6. India
1896-1918 Entered India
1918-67 Declined occasional cases
from endemic area
1967-1994 No cases
1994 Surat Epidemic-
Start-Beet Latur belt
(Maharashtra)
>6000 suspects
>60 deaths
2002 Rohru Shimla Outbreak 4 deaths
2004 Dangud village Uttarkashi
outbreak
8 cases
3 deaths
7. 4 Foci
1. Kolar-Trijunction of KAT—(Karnataka, Andra
Pradesh, TN)
2. Beed Latur Belt- Maharashtra
3. Rohru shimla HP
4. Dangud Village Uttarkashi
12. In man
Plague occur in three form
Bubonic Plague
Pneumonic Plague
Septicaemic Plague
13. Bubonic Plague
Bubo:groin
Tender Inguinal LAP
Rat flea bite on leg
Fever,chill,malaise with bubo
Incubation period 2-7 d
Mortality :30-90%
14. If not treated
Bacteremia
IP 2-7 d
Blood vessel involved
Hemorrhage in skin & mucosa---
Gangrene of affected area
Black death
If crosses blood brain barrier
:meningeal plague
15. Pneumonic Plague
Most dangerous variety
Virtually always fatal
Most infectious (Droplet)
Involves lung
Hemorrhagic pneumonia
Short IP (1-3 d)
16. Specimen:
Bubonic plague :
Aspirate from bubo
Pneumonic Plague/Septicemic Plague :
Sputum, Blood, Splenic aspirate (Post
mortem)
Strict Bio safety Precaution is needed.
18. Microscopy:
Gram Stain :
GNB
Giemsa/ Methylene
blue (Wayson Stain)
Bipolar safety pin
appearance.
Antigen detection:
F1Glycoprotein
detection from
samples by IF/ELISA
19. Culture Characteristics
Aerobic /facultative anaerobic
Grow on ordinary media (slowly)
Ideal growth temperature :27 degree
Rapid growth in media containing
blood, body fluid
Small colorless(?) colony
Nutrient broth:
Ghee broth :Stalactites growth
20. Culture Characteristics
BA: Dark pigmented-Absorption of
hemin
MA-NLF
CIN (Cefsulodin Irgasan Novobiocin
Agar)-Selective medium-Sputum
Animal Inoculation:
Guinea Pig/ White rat—Badly putrefied
carcasses
21. Serology
Ab to F1 Ag: ≥128 Titer
Passive Haemagglutination)
IgG or IgM ELISA
Molecular
PCR targeting F1 Ag gen
Pesticin gene
Plasminogen activator gene
22. Diagnosis in Dead Rodent
Kerosene over
carcasses (to kill the
flea)
Buboes are present
in the cervical
reason
Buboes, liver, spleen
are processed like
clinical sample
24. Prophylaxis
Vaccine :
Killed Vaccine (Formalin):
Killed virulent strains(Haffkin institute Mumbai)
Short lasting immunity (<6mths)
Live vaccine: a virulent strains
Subunit Recombiant Vaccine (Under trial)
All contacts of pneumonic plague:
Doxy/ Tetracycline x 7days
25. Yersinia
Important species :
Y.pestis:
Plague in man & rodent
Yersiniosis
Y.pseudotuberculosis
Pseudotuberculosis in animals
Y.enterocolitica
Enteritis in man & animal
26. Y. enterocolitica Y.
pseudotuberculosis
Distribution Worldwide Northern Europe &
America
Serotypes (basis) 60 (O Ag)
(6 biotypes)
6 (O & H Ag)
Growth on MA Grow Well NLF Poor growth
Sugar Fermentation Sucrose, Cellobiose,
sorbitol
Rhamnose salicin,
melibiose
Ornithine
decarboxylation
+ -
VP + -
Ab to O Ag Late during
convalescent phase
Appear early in acute
phase
Beta lactamases
production
Nearly always not
29. C/F
Post infective Phenomenon (Adult)
Due to deposition of non viable
components in joints & Other site
Reactive arthritis: a/c HLA B 27
Erythema nodosum
Grave disease
SuperAg:
Scarlet fever in Russia
Izumi fever- Japan
Linked to Kawasaki ds childhood
30. Lab diagnosis
Culture
BA: Beaten copper colony
Selective media: CIN: Dark red bull’s eye
colony
Cold enrichment: Phosphate buffered
saline at 40C x 3 week