E coli infection.pdf

By assist. lecturer: Iman K. alabadi Poultry diseases _ 4th stage 1/10/2023Sun. Avian Colibacillosis Synonyms: E. coli infection Generally, a secondary bacterial infection causing many different signs and lesions in chickens and tur...

By assist. lecturer: Iman K. alabadi Poultry diseases _ 4th stage 1/10/2023Sun. Avian Colibacillosis Synonyms: E. coli infection Generally, a secondary bacterial infection causing many different signs and lesions in chickens and turkeys. Etiology: Escherichia coli (APEC) – Gram negative rods – Rod (bacillus) shape – Non-spore forming – Motile Epidemiology: – Incubation period of 3-5 days. – All types of avian affected and all ages. – E. coli causes major economic losses in the poultry industry. – E. coli from avian sources do not cause problems in mammals. While chickens can carry some strain of E. coli that are pathogenic to humans. E. coli and Salmonella has been consistently associated with foodborne illnesses in most countries of the world. – E. coli is not part of “normal flora” of seed eating birds. It is more often seen in birds that eat protein of animal origin like poultry. – Mortality: Variable usually high in acute conditions but negligible in chronic problems. Transmission: – Fecal oral route – trans-ovarian – Contamination of the egg shell via fecal material from hen Predisposing factors: – Poor navel healing – Immunosuppression. – Mucosal damage or respiratory stress caused by infections with Mycoplasma gallisepticum or viral agents such as infectious bronchitis virus (IBV), Newcastle disease virus (NDV) and Infectious bursal disease (IBD) – Environmental and management influences, such as temperature, humidity, overcrowding and high concentrations of ammonia and dust. – Duration of exposure, virulence of the strain, breed, and immune status of the bird By assist. lecturer: Iman K. alabadi Poultry diseases _ 4th stage 1/10/2023Sun. Types of Infection: Localized or systemic infection depend on where primary problem occurs and entirely or partly Avian Pathogenic Escherichia coli (APEC). ❖ Coliform Airsacculitis: Respiratory condition along with mycoplasma or virus infection (IB) – 3-7 wk. old broilers – Many times, will follow another respiratory disease. – Associated with dusty litter – Signs and lesions vary – Respiratory signs, coughing, sneezing – Thickened air sacs with caseous exudate – Fibrinous pericarditis and perihepatitis (Friable material covering air sacs, liver and pericardial sac) ❖ Acute septicemia (coli septicemia) – Depression, fever and high mortality – Characterized by sudden death food still present in crop – lesions ▪ Swollen internal organs ▪ Petechial hemorrhages on the pericardium and abdominal fat. ▪ Liver greenish with small necrotic foci ▪ Green discoloration following exposure to air ▪ Odor ← Indole production – Resembles fowl typhoid and Fowl cholera ❖ Neonatal E. coli septicemia – Chickens in the first 24 - 48 h after hatching are affected. – The death rate during the first ten days is higher and could reach 5 - 6%. – The yolk sac is unabsorbed. – The spleen is enlarged. – Some days later, the typical serofibrinous lesions, affecting the peritoneum, the pericardium, the air sacs and the liver capsule are manifested. ❖ Omphalitis: embryo & early chick mortality – Definition/Synonyms: 1. Mushy Chick Disease 2. Yolk sac infection 3. Inflammation of the Navel 4. Inflammation of the umbilicus 5. Navel ill By assist. lecturer: Iman K. alabadi Poultry diseases _ 4th stage 1/10/2023Sun. – Most are mixed bacterial infections: 1. E. coli 2. Salmonella spp. 3. Staphylococci 4. Clostridia 5. Pseudomonas spp. 6. Proteus spp. 7. Bacillus spp. (esp. B. cereus) – Route of Infection: ▪ Fecal Contamination of eggs, Dirty hatcheries ►Contamination of unhealed Navel ▪ in ova contamination ►Oophoritis/Salpingitis/Artificial Insemination ▪ Intestinal contamination ▪ Hematogenic – High mortality during 1st Week – Lesions Navel area swollen and inflamed (reddening and tissue edema in the umbilical region) Wet abdomen or abdominal distension Delayed absorption of the yolk sac and yolk sac is distended, hyperemic and filled with abnormal brown, watery contents with foul smelling. – Peritonitis as Sequel ❖ Enteritis Enterotoxigenic E. coli (ETEC) are occasionally isolated from poultry suffering from diarrhea Clinical signs: – Depressed – Diarrhea, mucoid enteritis – Exudate soiled vent area Postmortem lesions: The intestines are pale and distended, particularly the ceca that are overfilled with fluid containing many gas bubbles By assist. lecturer: Iman K. alabadi Poultry diseases _ 4th stage 1/10/2023Sun. ❖ Salpingitis/Peritonitis (Adults) – Penguin status, ↓Egg production & Sporadic Mortality in Commercial Layers and Breeders – Affected birds usually never lay and die by 6 months – Predisposing factors: ▪ Heavy egg production → relaxing the sphincter between vagina & cloaca ▪ Mucosal Viral Infection (IB) ▪ Mycoplasmosis – Route of Infection: 1. Ascending from Cloaca 2. Spreading from air sacs (When the left greater abdominal air sac is infected by E. coli but more frequently in young birds) 3. Hematogenic due to septicemia – Oviduct distended with thinned wall and filled with yellowish-gray, cheese-like content. – Salpingitis can cause egg peritonitis as Sequel. ❖ Coliform cellulitis Synonyms:  Inflammatory process  Infectious process  IP – Host: Older chicken are more likely to develop cellulitis. – Commonly associated with respiratory disease in birds – No Ante-mortem clinical signs – Lesions:  An inflammation of the subcutis that extends beneath normal skin over the abdomen, leg or head.  Lesions are with a yellowish to red-brown color with Size 1-10 cm.  In the subcutaneous tissue, thick fibrinous plaques or thick serofibrinous exudate. ❖ Swollen-head syndrome (SHS) – Host: Chicken (broilers, broiler breeders & commercial layers), Turkey and Guinea fowl  Upper Resp. Viral E. Coli Infection Via Inflammatory ˗ Avian Pneumovirus Sinuses SHS exudate ˗ IBV Nasal cavity  ↑Ammonia levels Eustachian tube By assist. lecturer: Iman K. alabadi Poultry diseases _ 4th stage 1/10/2023Sun. – Clinical signs: Conjunctival inflammation, cranial and periorbital sinus swelling and edematous swelling over the eye. – Lesions: gelatinous edema of the facial skin & periorbital tissues & caseous exudate in the conjunctival sac & lacrimal gland. ❖ Coligranuloma (Hjarre’s disease) – Granulomas in GIT, liver, intestines and mesentery, but not in the spleen. – Uncommon, but in affected flocks it may cause up to 75% mortality – Looks like TB ❖ Synovitis, arthritis and Osteomyelitis and Osteonecrosis – Frequently a sequel to systemic infection – Lame or recumbent – Chronic tenosynovitis and chronic arthritic conditions may be seen – Swelling of tendon sheaths and joints with caseous exudate – Inflammation of joints, bone marrow and bone necrosis ❖ Panophthalmitis – Frequently a sequel to systemic infection (E. coli septicemia) – Inflammation of all tissues of the eyeball – The eye is swollen, cloudy to opaque, and may be hyperemic initially. – Hypopyon usually in one eye which is blind (unilateral) – Later, the eye shrinks as it undergoes atrophy. ❖ Oophoritis ˗ Is an inflammation of the ovary ˗ May infect the internal egg before shell formation ˗ Often seen in combination with salpingitis Diagnosis: Culture and ID, always assume isolated E. coli is secondary to another primary disease – MacConkey agar – EMB agar – Drigalki agar – Tergitol-7 agar ELISA By assist. lecturer: Iman K. alabadi Poultry diseases _ 4th stage 1/10/2023Sun. Differential Diagnosis – Acute and chronic infections with Salmonella spp – Mycoplasma – Respiratory virus – ND, IB – Staph. Infection – Fowl Cholera – TB Treatment: – Many antibiotic work, culture and sensitivity test should be done. – Don’t treat chicks with omphalitis – most E. coli are resistant to everything. – Enrofloxacin – Colistin – Lincomycin + Spectinomycin Control & Prevention – Minimize egg shell contamination, sanitation and fumigation – Obtain good quality disease free chicks – Ensuring proper housing climate ventilation, bird density, humidity. – Use feed that is free of feces – Chlorination of drinking water – Elimination of predisposing factors, including mycoplasmas, IBV, NDV, Aflatoxicosis, parasites, stress, Ammonia and Dust. – High protein diets, increased selenium and increased vitamins A and E – Competitive exclusion (CE): i.e., inoculating day-old chicks with normal bacterial flora of healthy adult chickens or a monoculture of Bacillus subtilis – Immunization  Inactivated Vaccines  Live Vaccines  Subunit Vaccines