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Re: [SANET-MG] no smoking cow?



Hello John , Lawrence, Brian, Sals and Jeff,
Regarding John's comment on calves with bloody stools. Early on in the study of E coli 0157 it was found that antibiotic treatment caused the bacterial cells to lyse (dissolve) releasing vero toxin that damaged the cells of the gut. Young animals tend to be treated with antibiotics to enhance growth. Such antibiotics lyse the cells leading to toxin release and activation of the prophage (virus) carrying toxin genes. Googling will turn up numerous publications showing that adult cattle carry E coli 0157 without showing any illness but the fact is so well established that more publications here seem unnecessary.The publications below tells how the antibiotics work to make calves sick..
Microbiology (2000), 146, 1085-1090.
Environmental Microbiology
Antibacterials that are used as growth promoters in animal husbandry can affect the release of Shiga-toxin-2-converting bacteriophages and Shiga toxin 2 from Escherichia coli strains
Bernd Köhler1, Helge Karch1 and Herbert Schmidt1

Institut für Hygiene und Mikrobiologie der Universität Würzburg, Josef-Schneider-Str. 2, D-97080 Würzburg, Germany1

Author for correspondence: Herbert Schmidt. Tel: +49 931 201 3905. Fax: +49 931 201 3445. e-mail: hschmidt@hygiene.uni-wuerzburg.de

Antibiotics are commonly used as growth promoters in animal husbandry worldwide. This practice has been linked to the emergence of particular antibiotic-resistant bacteria, and is now controversial. In this study, the ability of growth-promoting antibiotics to induce Shiga toxin (Stx)-converting bacteriophages from Stx-producing Escherichia coli (STEC) strains was investigated. Subinhibitory concentrations of the antibacterial growth promoters olaquindox, carbadox, tylosin and monensin were used for induction experiments. The amount of mature Stx-converting phage particles released from induced and non-induced cultures was determined, and the production of Stx was simultaneously measured by ELISA. Whereas the quinoxaline-1,4-dioxide-type antibiotics olaquindox and carbadox enhanced the release of Stx-converting phage particles from STEC cells, tylosin and monensin decreased phage induction. The production of Stx increased or decreased simultaneously with the amount of free phages. The results of this study show that particular antibacterial growth promoters can induce Stx phages. In vivo induction of Stx phages from lysogenic STEC may increase the amount of free phages in the intestine and therefore may contribute to the spread of STEC and development of new STEC pathotype

Along with the effect on animals it was found that people infected with E coli 0157 then treated with antibiotic were far more likely to get the extreme HUS syndrome because the antibiotic caused the bacteria to lyse. The studies below give that evidence.
http://www.medscape.com/viewarticle/410077
Escherichia coli Infection: Antibiotics Pose Risk of Hemolytic-Uremic Syndrome Antibiotic treatment of children infected with E coli 0157:H7 increases the risk of hemolytic-uremic syndrome. That, according to results of a study published in the June 29th issue of the New England Journal of Medicine.

Researchers conducted a prospective cohort study of 71 children, all younger than 10 years, who experienced diarrhea linked to E coli 0157:H7. They found that hemolytic-uremic syndrome developed in 5 (56%) of the 9 children who were administered antibiotics and in only 5 (8%) of the remaining 62 children.

Several clinical factors were significantly associated with hemolytic-uremic syndrome: high white blood cell counts on presentation, evaluation with stool culture soon after onset of illness, and treatment with antibiotics. The investigators say that the clinical and laboratory characteristics of the 9 children who received antibiotics and the 62 who did not were similar. This letter is getting long so I will provide more abstracts on antibiotic resistance along with the adult cow story in a following letter. Essentially what was given in this letter was the evidence that antibiotic may cause problems in people and cows infected with E coli 0157.
sincerely,joe cummins
John D'hondt wrote:
it is clear that healthy cattle frequently have E. coli in their intestines which does not cause them to have diarrhea or have any symptoms. E coli kills people but not cows because the human has a cell surface receptor on the cells of the gut that allow the bacteria to inject verotoxin into their cells, cows lack such those receptors. The healthy cattle could pick up E coli 0157 from a visit from the vet or from a neighbors car or truck.

Hi Joe, I am not so certain that cattle don't suffer from e. coli. At least many calves sold in Marts here in Ireland die from haemolitic E.coli infections. This means they die from bloody diarrhea. This mostly only happens to calves that have been taken away from their mothers prematurely as most calves are. A calf outside suckling a cow never gets this disease.

Also, three people died of this E.coli 0157 over a few weeks time. Do you know how many people in total died in the U.S. during this period? Or how many sickened for one reason or another? If one looks at the total picture it should be clear that this "disaster" was blown up out of all possible proportion. There are many times more people dying every hour of pesticide poisoning than ever died from this E.coli. Which does not mean that one should be careless with feed lot slurry of course.
john
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