Article

Grain feeding and the dissemination of acid-resistant Escherichia coli from cattle

Division of Biological Sciences, Section of Microbiology, Cornell University and Agricultural Research Service, U.S. Department of Agriculture, Ithaca, NY 14853-8101, USA.
Science (Impact Factor: 31.48). 10/1998; 281(5383):1666-8. DOI: 10.1126/science.281.5383.1666
Source: PubMed

ABSTRACT The gastric stomach of humans is a barrier to food-borne pathogens, but Escherichia coli can survive at pH 2.0 if it is grown under mildly acidic conditions. Cattle are a natural reservoir for pathogenic E. coli, and cattle fed mostly grain had lower colonic pH and more acid-resistant E. coli than cattle fed only hay. On the basis of numbers and survival after acid shock, cattle that were fed grain had 10(6)-fold more acid-resistant E. coli than cattle fed hay, but a brief period of hay feeding decreased the acid-resistant count substantially.

Full-text

Available from: Francisco Diez-Gonzalez, Jun 03, 2015
0 Followers
 · 
257 Views
  • Source
    [Show abstract] [Hide abstract]
    ABSTRACT: Özet Tüketiciler konvansiyonel olarak üretilen hayvansal ürünlere göre organik olarak üretilenlerin zararlı madde içermedikleri ve böylece daha sağlıklı ve kalitesinin daha iyi olduğuna inanmaktadırlar. Bu durum, muhtemelen organik üretimde hayvanları uygun yetiştirme sistemlerinde büyütülmesi, doğal yemlere serbestçe ulaşabilmesine, sentetik yem katkılarının ve rasyonlarda genetiği değiştirilmiş yem maddelerinin yasaklanması ve dolayısıyla daha sağlıklı ürün elde edileceği düşüncesine dayanmaktadır. Kimi araştırıcılar bu görüşleri doğrulayan düşünceler bildirirken kimileri ise organik ve konvansiyonel üretim metotları arasında önemli kalite farklılıklarının olmadığına ve kaliteye ilişkin beklentinin karşılanmasının zorluğuna dikkat çekmektedirler. Bu çalışma, organik ve konvansiyonel metotlarla elde edilen hayvansal ürünlerin kimyasal içerik, duyusal analizler, mikroorganizma yükü, kimyasal kalıntı ve ağır metaller bakımından karşılaştırılması amacıyla yapılmıştır. Anahtar kelimeler: Organik, konvansiyonel, hayvansal üretim Comparison of some animal product properties obtained from organic and conventional animals Abstract The consumers believes that the organic animal products not contain harmful substances and therefore they have good quality and healthier than conventional products. In this case, probably, organically produced animals grown under suitable breeding system, availability of natural feed sources freely, prohibition of supplementation of synthetic feed additives and genetic modified organism in the animal feeds and therefore healthier products can be obtained. Some of the researches have verified think, however some of them call attention to there are difficulties about meet of expectation in quality and there are no differences in quality properties of organic and conventional production system. This study carried to compare animal products provided in organic and conventional production system in terms of chemical content, sensual analyses, microorganism load, chemical residue and heavy metals. Keywords: organic, conventional, animal production
    1. Organik Tarım Kongresi, GÜMÜŞHANE; 08/2010
  • [Show abstract] [Hide abstract]
    ABSTRACT: The sensitivity of field isolates of STEC O157. O26 and reference strains from collections to different concentrations of sodium hypochlorite, sodium benzensulfochloramid (chloramine B), glutaraldehyde with glyoxal, peracetic acid and lactic acid was verified. The most effective disinfectant was peracetic acid at the concentration of 0,02%, followed by chloramine B and lactic acid at the concentration of 0.5%. The field isolate of STEC O157 in comparison with the other tested strains of E. coli was more resistant to the activity of peracetic both and lactic acid and to chlorine releasing disinfectants. Its resistance was comparable to that of reference E. coli strain CNCTC 301/60, which is the reference micro-organism for efficacy testing of disinfectants. Statistically significant difference among the individual tested strains was not found. Differences between the tested STEC strains and reference strains in evaluation of growth curves were shown. STECO157 and O26, more than the other tested strains, showed a higher resistance to acid environment in this characteristic. The reference E. colt strain CNCTC 301/60 and field isolate STEC E. coli O157 were the most resistant of all the tested strains, reference non toxigenic E coli O157 strain was the most resistant to aldehydes.
    Acta Veterinaria Brno 03/2003; 72(1):101-109. DOI:10.2754/avb200372010101 · 0.45 Impact Factor
  • [Show abstract] [Hide abstract]
    ABSTRACT: To estimate the prevalence of Escherichia coli O157 on Dutch dairy herds, faecal samples were collected once from 678 randomly selected dairy farms in the period October 1996–December 2000. Samples were cultured for E. coli O157. Thirty-eight isolates were tested for virulence genes (eae, VT1 and VT2). A questionnaire about farm characteristics was taken from the farm manager, resulting in variables that could be analysed to identify and quantify factors associated with presence of E. coli O157.In total, 49 of the 678 herds (7.2%) showed at least one positive pooled sample. E. coli O157 was not isolated from herds sampled in December–April in consecutive years (except for one isolate found in March, 2000). VT- and eae-genes were found in 37 and 38 isolates, respectively. Logistic regression was performed on variables obtained from the questionnaire, comparing E. coli O157-positive herds to negative herds. To account for season, a sine function was included in the logistic regression as an offset variable. In the final model, the presence of at least one pig at the farm (OR=3.4), purchase of animals within the last 2 years before sampling (OR=1.9), supply of maize (OR=0.29) to the cows, and sampling a herd in the year 1999 or 2000 (compared to sampling in 1998; OR=2.1 and 2.9, respectively) had associations with the presence of E. coli O157.
    Preventive Veterinary Medicine 05/2004; DOI:10.1016/S0167-5877(04)00084-4 · 2.51 Impact Factor