As published in E. coli Infections in Poultry By Eric Gingerich, DVM Technical Service Specialist - Poultry Diamond V Escherichia coli (E. coli for short) is a Gram negative bacterium that can cause a various forms of disease in poultry. Diseases caused by E. coli are called colibacillosis and may infect all classes and ages of poultry. The E. coli bacterium is ubiquitous wherever fecal material from animals is found. E. coli related diseases continue to be at or near the top of lists of disease issues for broilers, turkeys, and egg layers. The different disease syndromes and their control are described herein. Yolk infections in chicks and poults due to E. coli are primary infections from exposure to the bacterium during the hatching process. Egg shell contamination is the main reason for the exposure although poor hatcher sanitation can leave a residue of E. coli from the previous hatch. Losses normally occur during the first three days of life and present clinically as normal sized chicks on feed but dead. Lesions of caseous yolk material are often seen. Culture of this yolk material is used for diagnosis to differentiate from other possible bacterial causes such as Salmonella spp., Pseudomonas spp., Staph. aureus, etc. Treatment with antibiotics is normally not used because the course of the disease is so short-lived that by the time a diagnosis is obtained, the disease losses are nearly complete. Effective prevention means only utilizing clean hatch eggs by using effective nest management and sanitation techniques. Also, the use of an effective hatcher and hatcher tray sanitation program is important. The use of Diamond V Original XPC in feed can also be an aid as E. coli levels in the breeder feces will be less, reducing nest contamination. E. coli infections secondary to respiratory infections in broilers, egg-type pullets and layers, and turkeys, is an important disease scenario. The normal respiratory tract has the capability to remove E. coli and other bacteria from deep in the respiratory tract due to the action of ciliated epithelial cells lining the trachea. In respiratory disease situations such as Bordatella avium in turkey poults, infectious bronchitis in chickens, Mycoplasma gallisepticum infections in both turkeys and chickens, the epithelial cells of the trachea and bronchi of the lungs undergo changes that do not allow normal function of these cells. Hence E. coli numbers increase and infection of the respiratory tract occurs. The initial lesion seen when E. coli infection is established is a Diamond V 1 caseous airsacculitis. The deadly and chronic lesion seen with E. coli infection is a caseous peritonitis, perihepatitis, and/or pericarditis. House management practices can play a role in the incidence and severity of E. coli infections. Low ventilation rates that lead to high atmospheric ammonia, increased litter moisture, and high dust counts in the air all will aid in carrying more E. coli deep into the respiratory tissues. Increased litter moisture also has the effect of increasing the survivability and reproduction of E. coli bacteria. Egg layer colibacillosis is viewed as a primary disease due to E. coli. It is most often seen at the onset of egg production but can be seen at older ages as well. The sources of infection appear to be water, dust, or fecal material pecked off equipment. The stress of recent movement and the onset of egg production appear to be factors in the onset of the disease early in lay. One theory is that the young layer’s everted reproductive tract during egg laying is quite susceptible to infection with E. coli and the bacterium infects the bird by moving retrograde up the oviduct. Turkey poults suffer an E. coli related syndrome after viral enteritis. This is due to overgrowth of E. coli in the intestine from poor digestion of nutrients and a buildup of these undigested nutrients in the lower intestine. Poult death losses can be quite high with lesions seen as a septicemia or caseous peritonitis, perihepatitis, and/or pericarditis. Antibiotic treatment of older flocks infected with colibacillosis has met with much less success recently than in the past due to widespread antibiotic resistance and the lack of new and effective antibiotics to take their place. For example, there is only one antibiotic preparation available to treat bacterial infections in egg layers in production. The tetracyclines and sulfa drugs are available for use in broiler and turkey flocks. A very effective antibiotic, enrofloxacin, was taken away from the industry by FDA several years ago due to the ill-perceived notion that enrofloxacin was being used in feed or as a widely used preventative medication and not as a therapeutic as intended. Treatment now involves supportive measures to aid in reducing the level of infection for the remaining flock members as follows: • Vaccination with the live E. coli vaccine; • Fogging (nebulizing) disinfectants such as VirkonS or chlorine dioxide; • Sanitizing water with five to 10 ppm chlorine or six to 12 ounces of iodine disinfectant per gallon of stock solution metered at one ounce per gallon drinking water; • Collecting dead birds more frequently to remove them as a source of infection in an attempt to decrease the disease cycle; • Replacing wet litter with dry in floor houses; • Adding an intestinal health aid such as Diamond V Original XPC will give some immediate boost of the immune system while prolonged use will aid in improving the microflora makeup. Prevention of E. coli infections is therefore the main control measure used. Several preventative practices are available as follows: • Intestinal health aids. Several research-backed products are on the market. Diamond V Original XPC has been shown to reduce E. coli levels in the cecum when fed at recommended levels and would aid in reducing contamination levels in the birds’ environment and improve their response to invading bacteria. • Water sanitation. Routine sanitation of water with either chlorine or iodine can be very effective in reducing bacterial infections. • Vaccination. The live E. coli vaccine has been a very useful tool in egg layers and is being evaluated in broiler and turkey flocks. In egg layers, two to three doses are applied by spray during the growing period prior to housing. Booster applications are given to some flocks prior to molting. Diamond V 2 • • Ventilation practices. Reducing ammonia levels by providing the proper ventilation rates and temperatures throughout grow for broilers will keep litter dry and reduce the release of ammonia from the litter. Keeping the stored manure dry in high-rise layer houses is also important in reducing ammonia. The use of manure drying fans in the pits of highrise houses has been a great aid in reducing moisture of the manure piles. Moving age of egg layers. Moving egg layer pullets at least one to two weeks prior to the onset of production will aid in getting the birds’ microflora stabilized and the birds exposed to pathogens in the new layer house environment prior to the stress of egg production. Spreading out these stressors appears to reduce the problems with early lay E. coli problems in egg layers. Typical lesions of colibacillosis in layers – Caseous Peritonitis Lesions of Colibacillosis in a Broiler – Caseous pericarditis and perihepatitis Diamond V 3 Colibacillosis in a chick – Note full crop and enlarged yolk full of caseous exudates Copyright 2011 Diamond V All rights reserved. Diamond V 4