Test 2- Yersinia

Question 1

Yersinia pestis

Answer 1

• Humans (cats)
• Bubonic plague; local lymphadenitis
• Pneumonic plague: pneumonia
• Septicaemic plague: septicaemiae
• ‘Black Death’

Question 2

Yersinia pestis Epidemiology

Answer 2

• 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

Question 3

Yersinia pestis Virulence factors

Answer 3

• Capsule
• Toxins (many different)
• Iron acquisition
• Many virulence genes are located on plasmids

Question 4

Yersinia pestis Epidemiology

Answer 4

• 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

Question 5

Yersinia pestis Infections in cats (including wild cats)

Answer 5

• After ingestion of infected pray
• Symptoms
• Fever, depression, sneezing, coughing, CNS disturbances • Lymphadenitis, tonsillitis, cranial and cervical edema, pneumonia
• Mortality

Question 6

Yersinia pestis Dx and tx

Answer 6

• Diagnosis
• Culture
• PCR
• Serology

• Treatment

• Antibiotics
• Rarely acquired resistances

Question 7

Yersinia pseudotuberculosis

Answer 7

• Closely related to Y. pestis
• Obligate symbiotic
• Pathogenic significance: • Rodents • Birds • Zoonotic • Facultative intracellular

Question 8

Yersinia pseudotuberculosis Virulence factors

Answer 8

• Cell wall: endotoxin
• Adhesins; Adhesion on basolateral ileal epithelial cells and M cells
• Toxins (on plasmids)
• Iron Uptake (on Pathogenicity Islands)

Question 9

Yersinia pseudotuberculosis Pathogenesis

Answer 9

• 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

Question 10

Yersinia pseudotuberculosis Major pathogen in Passeriformes

Answer 10

• “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

Question 11

Yersinia pseudotuberculosis Major pathogen in Passeriformes, symptoms

Answer 11

• 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

Question 12

Yersinia pseudotuberculosis Major pathogen in Passeriformes Dx, DD, Tx

Answer 12

• Diagnosis

• Culture

• DD

• Salmonella
• Mycobacteria

• Treatment

• Antimicrobials
• Chronic cases: very difficult

——— Better to cull (lowering contamination of environment)

• Hygiene

Question 13

Other animal species

Answer 13

• Rare
• Occasionally in turkeys:
• High mortality in young animals
• Acute sepsis with enteritis

Question 14

Yersinia enterocolitica

Answer 14

• 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

Question 15

Yersinia ruckeri

Answer 15

• Enteric red-mouth disease
• Systemic bacterial Illness of salmonids
• Intensively cultured rainbow trout in warm waters
• Hemorrhagic inflammation of organs perioral subcutis
• Significant mortalities