Colibacillosis refers to any localized or systemic infection caused entirely or partly by avian pathogenic Escherichia coli (APEC),  It manifests in diverse ways, including as acute fatal septicemia, subacute pericarditis, peritonitis, and cellulitis. It is frequently associated with immunosuppressive diseases such as Infectious Bursal Disease Virus (Gumboro Disease) in chickens or Haemorrhagic Enteritis in turkeys, or in young birds that are immunologically immature. 

1. Colibacillosis in Poultry
Chapter # 14

2. Introduction
 Colibacillosis refers to any localized or systemic
infection caused entirely or partly by avian
pathogenic Escherichia coli (APEC), It manifests in
diverse ways, including as acute fatal septicemia,
subacute pericarditis, peritonitis, and cellulitis.
 It is frequently associated with immunosuppressive
diseases such as Infectious Bursal Disease Virus
(Gumboro Disease) in chickens or Haemorrhagic
Enteritis in turkeys, or in young birds that are
immunologically immature.

3. Etiology
Avian pathogenic E. coli, is a gram-negative,
non-spore-forming bacillus. Somatic (O) and
capsular (K) antigens are often used to
designate serotypes.
Serotypes with the somatic antigens 1, 2, 35,
and 78 are frequently associated with
disease in poultry. Most of the strains are
motile.

4. Pathogenesis
• E. coli is present in the intestinal tracts of
birds and mammals and is widely
disseminated through fecal material into the
environment. If susceptible birds
(immunosuppressed) or damaged tissues get
exposed, E. coli may colonize and cause
disease.

5. Clinical signs
Colibacillosis usually is signaled by the
appearance of diarrhea.
Signs vary and can include
Acute fatal septicemia(Poising of blood)
Airsacculitis, pericarditis, perihepatitis, and
lymphocytic depletion of the bursa and
thymus.

6. Transmission
 The disease is transmitted via direct contact, fecal-
oral and fomite contamination.
 A high carbohydrate or vitamin imbalanced diet.
 Exposure to infected animals
 Shipment stress, overcrowding, and lack of fresh
water are stressful events that precipitate
development of disease.
 Avian colibacillosis and salmonellosis are
considered to be the major bacterial diseases in the
poultry industry world-wide. Colibacillosis and
salmonellosis are the most common avian diseases
that are communicable to humans.

7. Diagnosis
 Genotyping by multiplex PCR is widely practiced to
determine specific pilus and toxin genes present in
the isolate.
 Isolation of serotypes of E. coli associated with
disease in poultry in the absence of other primary
pathogens and their serological fingerprints.
 Through bacterial culturing on culture media i.e
Mackonkey agar or Blood agar(SS agar) for E.coli
and Salmonella.

8. Prevention
Strengthen measures to clean and disinfect
fertile eggs from the breeder flocks. Avoid
incubating floor eggs.
Increase sanitation in the hatchery.
 Reduce the risk of primary pathogens using
biosecurity and vaccination in poultry flocks.
Reducing ammonia and dust levels in the
barns may help reduce the environmental
insult that E. coli commonly needs to gain
access into a flock.

9. Treatment
Antibiotics such as tetracyclines, sulfas,
ampicillin, and streptomycin have been
successfully used to control some E. coli.
Early treatment is advised, with a follow-up
considering antibiotic sensibility testing
using the specific isolate.
As the organism gets encapsulated or
sequestered into caseous exudate, the
antibiotic treatment will be less effective;
thus, chronic stages of infection have a
lower chance of being successfully treated.

10. Epidemiology
 Colibacillosis has a worldwide presence. Mostly in
developing countries i.e. African countries and third
world countries where proper care of poultry is not
taken.
 It affects all types of poultry, wild birds, and
mammals. Infections in poultry are generally linked
to suboptimal sanitation in the hatchery and/or poor
environmental conditions in the barn, or it occurs
after birds have been affected by another primary
agent or immunosuppressive disease

11. Thank you
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