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Colibacillosis

Colibacillosis (E.coli infections in poultry)

Etiology

Colibacillosis

Localized or systemic infection ♦ Entirely or partly by Escherichia coli ♦ Gram -Ve, non-spore forming, non-acid fast, motile bacillus ♦ O (173), K (74), H (53) and F (17) antigens recognized ♦ Most common serotypes are O1, O2, O35 and O

Diseases Caused by E.coli

Colibacillosis

♦ Colisepticaemia ♦ Yolk sac infection / Omphalitis/Mushy Chick Dis. ♦ Air-sac disease (CRD with E.coli - CCRD) ♦ Egg peritonitis ♦ Arthritis/Synovitis / Osteomyelitis ♦ Panophthalmitis ♦ Coligranuloma (Hjarre's disease) ♦ Swollen Head Syndrome ♦ Avian cellulitis ♦ Salpingitis

1. Colisepticaemia

Colibacillosis

Source and spread of infection ♦ Ubiquitous in nature - Cosmopolitan distribution. ♦ Common inhabitant in the intestinal tract of poultry. ♦ Feed, water, litter, faecal material, dust particles inside poultry shed, rodent droppings are the source of infection. ♦ Totally horizontal spread. No vertical spread.

Colibacillosis

Pathogenesis (Route of infection)

♦ In poultry it is respiratory infection. ♦ Through inhalation of dust particles and

droplets of affected birds. ♦ Incubation period is short. ♦ Predisposing factors are very important.

Colibacillosis

Predisposing factors ♦ Live vaccine virus - LaSota, IB ♦ Damaged skin or mucosal barrier ♦ Ammonia, dust particles ♦ Poor ventilation ♦ Overcrowding ♦ Mycoplasma infection ♦ Stresses of various nature ♦ Immunosuppression ♦ Viral respiratory diseases like RD, IB etc.

Colibacillosis

Incidence ♦ Young one are more susceptible than adults ♦ Broiler chicks are more prone than layer

chicks ♦ Broilers of 3-6 weeks are more susceptible ♦ Mortality from few birds to as high as 50%

Colibacillosis

Clinical signs • • • •

Not specific Respiratory rales Nasal discharge Conjunctivitis

Colibacillosis

Post-mortem lesions ♦ Fibrinous pericarditis and fibrinous perihepatitis. ♦ Trachea highly congested with presence of white

cheesy material. ♦ Air sacs - cloudy, frothy, thickened and in long

standing condition filled with cheesy material.

Diagnosis

♦ Clinical signs ♦ Post-mortem lesions ♦ Cultural isolation

Colibacillosis

Prevention ♦ Pelleted feed ♦ Avoid animal protein sources in feed ♦ Nutritionally balanced feed ♦ Maintain immune status of birds ♦ Use of water sanitizer ♦ Avoid dusty litter and excessive ammonia ♦ Procure Mycoplasma free chicks ♦ Prevent rolling of vaccine virus ♦ Use enteropathic vaccine strains. ♦ Protect chicks against IB, ND, AI, CRD, IBD etc. ♦ Follow All In All Out Management

Colibacillosis

Treatment ♦ After drug sensitivity test ♦ Fluroquinolone group antibiotics ♦ Use antibiotics in combination

Vaccination ♦ No satisfactory vaccine

Colibacillosis

2.Yolk sac infection ♦ Disease of young chicks ♦ Mortality from 3rd day, peaks on 5th, 6th days and

then subside. ♦ More in chicks from deep litter parents. ♦ Mixed infection of E.coli, B.subtilis, Staph aureus ♦ Faecal contamination of eggs - most important source of infection. ♦ No vertical transmission ♦ Chicks often have Omphalitis ♦ Low brooding temperature or fasting increases incidence

Colibacillosis

Post-mortem lesion ♦ Swollen abdomen ♦ Congested

or haemorrhagic, enlarged, unabsorbed yolk with curdled appearance and foul smell. ♦ Sometimes yolk sac peritonitis.

Colibacillosis

Treatment and Control ♦ Antibiotics are ineffective ♦ Clean hatching eggs collection and proper

fumigation. ♦ Rearing of parents in cages.

Colibacillosis

3.Arthritis / Synovitis / Osteomyelitis Alone or with Mycoplasma and reo virus, E.coli produces arthritis and Synovitis. ♦ Sequelae to septicemia ♦ Spondylitis, progressive paresis and paralysis.

4. Panopthalmitis E.coli infection of anterior chamber of eye results into pus formation. ♦ Complete destruction of retina. ♦ Eye become whitish.

Panophthalmitis

Colibacillosis

5. Coligranuloma (Hjarre's disease) ♦ Uncommon disease ♦ Granuloma in liver, caeca, duodenum, mesentry

but not spleen.

6. Swollen head syndrome (SHS) ♦ Acute to sub acute cellulitis involving the

periorbital and adjacent subcutaneous tissues of the head. ♦ E.coli, unidentified corona virus - associated with infection. ♦ Avian pneumovirus, IB virus, poor ventilation, high NH3 level - predisposing factors. ♦ Periorbital inflammation is typically seen early in

Coligranuloma

Colibacillosis

7. Avian cellulitis

Chronic skin disease affecting the abdomen of broiler chickens. ♦ Characterized by sheets of caseated, heterophilic exudate in subcutaneous tissues. ♦ Lesions in the skin between thigh and sternum. ♦ Important cause of condemnation.

8. Salpingitis ♦ Entry of coliform bacteria from cloaca may cause

salpingitis. ♦ Left abdominal air-sac infected with E.coli female may develop salpingitis. ♦ Characterized by large caseous mass in a dilated, thin walled oviduct.

Colibacillosis

9. Air-sac disease ♦ E.coli

infects respiratory tract of birds concurrently infected with IBV or NDV or vaccine strains or Mycoplasma. ♦ Economic losses - mortality, morbidity, condemnation. ♦ Infected air-sacs - thickened, often caseous exudate on the respiratory surface.

10. Egg peritonitis ♦ In laying hens - mortality, fibrin and free yolk in

peritoneal cavity. ♦ Ascending infection through the oviduct.