Test 2- Yersinia Flashcards
Yersinia pestis
- Humans (cats)
- Bubonic plague; local lymphadenitis
- Pneumonic plague: pneumonia
- Septicaemic plague: septicaemiae
- ‘Black Death’
Yersinia pestis Epidemiology
- Fleas of wild rodents (epidemiology elucidated in London) Killed 25% of the London population
- John Graunt (1620–1674): one of the first epidemiologists, demographer and statistician through the study of the great plague in London
Because of its high pathogenicity: weaponized
Yersinia pestis Virulence factors
- Capsule
- Toxins (many different)
- Iron acquisition
- Many virulence genes are located on plasmids
Yersinia pestis Epidemiology
- Endemic areas
- Western North America, southern Asia, Southern and west Africa, north- central South America
- Mainly in warm months: temperatures above 27C, Y. pestis does not produce a coagulase that blocks the fleas proventriculus (where Y. pestis XXX)
• Parallels presence of rodent hosts (enzootic and epizootic)
• Historically from ships
• Today mainly from rural wild animals (Sylvatic plague)
• Reservoir
——— Tolerant rodents
• Transmission
——— Fleas
——— ————– Multiplication in proventriculus
——— Airborne
——— oral
Yersinia pestis Infections in cats (including wild cats)
- After ingestion of infected pray
- Symptoms
- Fever, depression, sneezing, coughing, CNS disturbances • Lymphadenitis, tonsillitis, cranial and cervical edema, pneumonia
- Mortality
Yersinia pestis Dx and tx
- Diagnosis
- Culture
- PCR
- Serology
• Treatment
- Antibiotics
- Rarely acquired resistances
Yersinia pseudotuberculosis
- Closely related to Y. pestis
- Obligate symbiotic
- Pathogenic significance: • Rodents • Birds • Zoonotic • Facultative intracellular
Yersinia pseudotuberculosis Virulence factors
- Cell wall: endotoxin
- Adhesins; Adhesion on basolateral ileal epithelial cells and M cells
- Toxins (on plasmids)
- Iron Uptake (on Pathogenicity Islands)
Yersinia pseudotuberculosis Pathogenesis
• Humans
- Oral uptake
- Lymphoid tissue intestine
- Mesenterial lymph nodes
- Colic
• Birds & rodents
- Oral uptake
- Lymphoid tissue intestine
- Mesenterial lymph nodes
- Sepsis and XXX in blood
Yersinia pseudotuberculosis Major pathogen in Passeriformes
- “fat liver disease”, “rodentiosis”
- Mainly in animals housed in outdoor birdhouses
- Transmission from wild birds and rodents
- Symptoms:
- Apathy
- Water and feed intake decrease
- Event. diarrhea
- Chronic: weight loss and respiratory distress
Yersinia pseudotuberculosis Major pathogen in Passeriformes, symptoms
• Lesions acute
- Typically very large spleen with foci of necrosis
- Enlarged liver
• Lesions subacute and chronic
- Very large spleen with foci of necrosis
- Very large liver with foci of necrosis
- Foci of necrosis on caeca and lungs
Yersinia pseudotuberculosis Major pathogen in Passeriformes Dx, DD, Tx
• Diagnosis
• Culture
• DD
- Salmonella
- Mycobacteria
• Treatment
- Antimicrobials
- Chronic cases: very difficult
——— Better to cull (lowering contamination of environment)
• Hygiene
Other animal species
- Rare
- Occasionally in turkeys:
- High mortality in young animals
- Acute sepsis with enteritis
Yersinia enterocolitica
- Domestic animals
- Ileitis
- Gastro-enteris
- Zoonosis (rather mild symptoms)
- Colic
- diarrhea
• Several serogroups and biotypes
- Colonizes terminal ileum
- Serotype O9: Cross reaction with Brucellosis serology
Yersinia ruckeri
- Enteric red-mouth disease
- Systemic bacterial Illness of salmonids
- Intensively cultured rainbow trout in warm waters
- Hemorrhagic inflammation of organs perioral subcutis
- Significant mortalities