126. Escherichia coli diseases in poultry.

Question 1

Occurence Ethiology and epidimiology?

Answer 1

Occurrence : Worldwide

Ethiology

• • Caused by invasive E. coli strains (APEC ʹ avian pathogenic E. coli),
• virul. f.: F1, F11 frimbia,
• surface proteins
• o Virulence variants

Epidemiology

• Infection:
• Horizontal ʹ feces, indirect,
• wounds; vertical ʹ eggs (germinative)
• Predisposing factors ʹ
• managem. problems,
• overcrowding,
• nutrit. deficiencies,
• other inf.: mycoplasma, viruses
• Disease is influenced by ʹ
• virulence of the agent,
• age of host,
• way of infection,
• predisposing factors

Question 2

Pathogenesis?

Answer 2

PATHOGENESIS

• Infection
• Embryonal infection (germinative, eggshell) ʹ death or week chicken will be hatched
• Inhalation (hatchery) ʹ replication in respiratory airways, local lesions (air sacculitis)
• Per cutaneous ʹ cellulitis, per os
• Replication in the gut Æ septicemia Æ endotoxin effect, parenchymal organs, endothelial cells,
• serous membranes inflammation, death
• Septicemia
• Young ʹ endodoxin effect ʹ death
• Grower, adult ʹ pericarditis, perihepatitis, airsacculitis, arthritis
• Hen ʹ coli-granulomatosis ʹ liver & gut
• Æ inflammatory granuloma around E. Coli
• Death

Question 3

Clinical signs?

Answer 3

CLINICAL SIGNS

• Day-old chicken ʹ
• navel inflammation (omphalitis),
• delayed absorption of the yolk sac,
• diarrhea,
• death
• Growers, adults ʹ
• septicemia (immunosuppressive effects),
• dyspnea,
• respiratory signs,
• arthrtitis,
• cellulitis

Question 4

Post Mortem lesions?

Answer 4

POST MORTEM LESIONS

• Day-old chicken ʹ
• enteritis,
• hemorrhages,
• fibrinous pericarditis
• Growers, adults ʹ
• septicemia (hemorrhages, enlarged parenchymal organs)
• o Chronic ʹ
• airsacculitis,
• peritonitis,
• fibrinous pericarditis,
• perihepatitis,
• salpingitis,
• granulomas in skin,
• ovarium and gut

Question 5

Diagnosis?

Answer 5

DIAGNOSIS

• • Epidemiology,
• clinical signs
• post mortem lesions
• • Bacteriological examination ʹ isolation from the bone marrow
• • Identification of the primary agent (CRD, NDV, Infectious bursitis)

Question 6

Treatment and prevention?

Answer 6

TREATMENT

• • Antibiotics in drinking water (colistin, ampicillin, enrofloxacin)
• • Treatment of primary agent ʹ e.g. mycoplasma Æ tiamulin + OTC

Prevention of infection,

• good hygiene in hatchery,
• strict disinfection,
• all-in-all-out,
• probiotics,
• vaccines