# E.Coli



## upcd (Mar 12, 2005)

Commonly known, “E. coli” is probably as widespread a bacterium as exists on earth. Not all E. coli produce disease, but when it does, the infection is called “colibacillos.” E. coli is associated with the feces of all types of all animals, including human feces. It is a normal constituent of pigeon feces, although not all scientific entities recognize it as “normal”
E.coli can be isolated from the feces 90% of the time; therefore, the statement can be made that we can isolate it even from normal pigeons. So, if you can get a culture report which reports E. coli, then don’t necessarily interpret this as disease. 
There are many, many different serotypes of E. coli. Serotypes are just different subspecies that can be identified by the process of serotyping. Serotyping is tedious and expensive, and done by very few laboratories. Some serotypes are more pathogenic than others. Pathogenic means that a bacterium has the ability to cause disease. The pathogenicity of different serotypes is frequently specific for one or more species of animals. In other words, what might be highly pathogenic to swine may not be pathogenic to cattle, humans or pigeons.
In the practical world, because of the tremendous expense, all of these specimens cannot be sent for serotyping. There is also a lack of scientific guidelines to interpret which serotypes exist in pigeons. Dr. Ron Van Ryswyk in Michigan did much work several years ago on E. coli in pigeons and did find that certain serotypes were more involved when there was actual disease.
To determine whether a particular E. coli serotype causes disease in pigeons can be very difficult, but whenever we can isolate E. coli from the sites in the pigeon, other than in the feces, such as the liver, spleen, brain tissue or kidney, it pretty much clinches that its presence is causing disease. If E. coli is confined to the feces, it is not normally suggestive of an infectious disease, although there are cases where it is so confined, and then causes some degree of disease in pigeons.
We use sever factors to help us decide whether the presence of E. coli in droppings should be treated. One factor is the number of E. coli organisms cultured. This is a quantitative element, and it’s not always meaningful, especially if the feces have spent a couple of days in the mail. The larger the numbers of E. coli that we find, the more suspicious we become. The sicker the pigeons are, the more suspicious we are, and the more abnormal the droppings are, the more suspicious we become.
The kind of symptoms that pigeons will show with a true E. coli infection can range from a few vague symptoms to all the symptoms that you can see with paratyphoid, such as embryos dying in the egg, youngsters dying in the nest, sore joints, going light, sudden death in breeding stock, diarrhea, and occasionally, blindness in one or both eyes. I know that E. coli has been isolated from the brain, so I would imagine, in some cases, it could cause the “twisted neck” symptom, but, even with paratyphoid, that is an uncommon symptom.
The main symptoms that we see that suggest E. coli infection are vomiting and abnormal mucoid droppings, especially if the droppings have a peculiar odor. These things suggest, but they are definitely not diagnostic, of E. coli.
There may be something else underlying an infection in any given pigeon, and E. coli may be only a secondary problem. We do know that a pigeon sick with anything, including parasites or viral infections, has an increase in the numbers of E. coli, and the E. coli can cause secondary infection.
E. coli bacteria are very opportunistic. They can exist in a non-disease forming state, and if the status quo is disturbed by another disease, E. coli has the capability of invading and producing an additional disease with symptoms of its own, thus piggybacking on some other disease process.
This leads some to conclude that if the birds aren’t right, and all that can be found is E. coli in the droppings, they often assume that that’s what is causing the problem. Many fail to realize that another disease – the main disease process – is the primary infection. They treat with a specific antibiotic for E. coli, wait to see the kind of improvement, but then, there seems to be a resurgence of symptoms. They actually are not treating the underlying problem, only the secondary E. coli infection.
The antibacterial products that historically have been effective against E. coli, especially Vetisulid and some of the other products, do not seem to be as effective, today. They do work sometimes, but less frequently. That is because the E. coli has become resistant to any antibiotics that they are exposed to repeatedly.
Vetisulid, the “original” E. coli drug, was overused because it is also a coccidiosis medication. It was marketed as an E. coli treatment for cattle, and the pigeon community latched onto it. The constant use by pigeon flyers for both E. coli and coccidian has produced generations of E. coli more resistant to that drug, in pigeons. Other E. coli medications that have been effective are Amoxicillin, Cephalexin, Trimethoprim/sulfa and Baytril.
Each drug can affect certain serotypes that the others do not. It can be a very expensive proposition, if you treat with everything using the shotgun approach. It would be cheaper to get a culture and sensitivity study done.
Let’s explain that for the layman. To have the feces cultured is to actually grow the E. coli if it is present in the droppings. Once it is isolated, the E. coli can be “grown” then tested again against various antibiotics to see which ones that this particular serotype is sensitive to, and which ones will possibly kill it outright.
Therefore, culturing is advisable because, too often, the wrong antibiotic is used – an antibiotic that can be quite expensive – so you have to start all over. The more we treat indiscriminately, hoping that a medication might work, but without really knowing, the more problems we’re going to see with resistant organisms.


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