Grain feeding and 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: 33.61). 10/1998; 281(5383):1666-8. DOI: 10.1126/science.281.5383.1666
Source: PubMed


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.

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Available from: Francisco Diez-Gonzalez
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    • "Diez-Gonzalez, Callaway, Kizoulis, and Russel (1998) observed higher numbers of E. coli in the feces of cattle that were fed diets consisting of higher amounts of grain. Additionally , when cattle diets were switched from a 90% grain diet to a hay diet, these authors observed nearly 10 6 fold fewer E. coli after only five days from the diet alteration (Diez-Gonzalez et al., 1998). They also concluded that grain was more efficient with regard to cattle performance, and that strictly forage-based diets were unlikely to become commonplace in American cattle feed. "
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    ABSTRACT: Commensal Escherichia coli are commonly utilized for investigating the genetic and biochemical requirements of microorganisms, and have served in a wide variety of applications. Pathogenic E. coli known as Shiga toxin (Stx)-producing E. coli (STEC) are associated with various food products including ground beef. These pathogens are present in a wide range of environments, and have caused numerous foodborne outbreaks and recalls. These outbreaks and the increased awareness of STEC have led to certain STEC serotypes to be declared adulterants in non-intact raw meat. Various STEC detection methods have been investigated, and numerous cultural and molecular-based detection methods continue to be modified to meet regulatory requirements. However, STEC serotypes may possess certain characteristics that lead to bias in the likelihood of a certain serotype being detected in an assay. Understanding the characteristics of these STEC serotypes will provide means for optimizing the detection platforms, and as a result limit foodborne illness and recalls caused by STEC due to enhanced cultural and molecular detection capabilities.
    Full-text · Article · Jan 2016 · Food Control
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    • "In the lower GIT, Van Kessel et al. (2002) observed 10 5 to 10 6 cfu/g digesta from the cecum and similar concentrations in the feces. Other studies have seen E. coli counts in digesta from colon and in feces of 10 6 to 10 7 /g (Diez-Gonzalez et al., 1998; Berry et al., 2006; Wells et al., 2009). Collectively, the results indicate that for generic E. coli, the lower GIT is a primary habitat in the bovine, but concentrations are 1 to 0.1% of the total culturable anaerobic bacteria (Van Kessel et al., 2002). "
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    ABSTRACT: Shiga-toxigenic Escherichia coli, such as E. coli O157:H7, are foodborne zoonotic pathogens that can cause severe illness and death in humans. The gastrointestinal tract of ruminant animals has been identified as a primary habitat for E. coli O157:H7 and, in cattle, the hindgut tract appears to be a primary site for colonization. This pathogen has been found in cattle feces, on cattle hides and in the production environment, and transmission to humans has occurred as a result of consumption of contaminated ground beef, water, and produce. Interventions to reduce the pathogen at beef harvest have significantly reduced the occurrence of the pathogen, but outbreaks and recalls due to the pathogen still occur for beef products. Interventions in the feedyard prior to harvest have had little success, but critical control points for implementing interventions are limited compared with the beef abattoir The percentage of animals shedding E. coli O157:H7 in the feces can be highly variable from pen to pen, and the levels in the feces can vary from animal to animal. Animals colonized and shedding E. coli O157:H7 at high levels are a small fraction of animals in a pen, but are important source for transferring the pathogen amongst the penmates. Recent research has indicated that diet may greatly influence the shedding of E. coli O157:H7. In addition, diet can influence the microbiota composition of the feces. However, little is known about the interaction between the indigenous microbiota and fecal shedding of E. coli O157:H7. Understanding the influence of indigenous microbiota on the colonization and shedding of E. coli O157:H7 will provide a potential avenue for intervention in the preharvest production environment not yet exploited.
    Preview · Article · Feb 2014 · Journal of Animal Science
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    • "Studies have indicated that varying the forage to grain ratio in cattle rations can have a marked effect on populations of E. coli. Some studies indicated that over feeding grain increased generic E. coli and/or O157:H7 populations [7,26-28]. Although E. coli O157:H7 was not detected in any of the present samples and Streptococcus pluranimalium and Campylobacter spp. "
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    ABSTRACT: Background Sub-acute ruminal acidosis (SARA) is a well-recognized digestive disorder found in particular in well-managed dairy herds. SARA can result in increased flow of fermentable substrates to the hindgut, which can increase the production of volatile fatty acids, alter the structure of the microbial community, and have a negative effect on animal health and productivity. However, little is known about changes in the structure of the microbial community and its relationship with fatty acids during SARA. Four cannulated primiparous (60 to 90 day in milk) Holstein dairy cows were assigned to two diets in a 2 × 2 crossover experimental design. The diets contained (on a dry matter basis): 40% (control diet, COD) and 70% (SARA induction diet, SAID) concentrate feeds. Samples of ruminal fluid and feces were collected on day 12, 15, 17 and 21 of the treatment period, and the pH was measured in the ruminal and fecal samples; the fecal microbiota was determined by pyrosequencing analysis of the V1–V3 region of amplified 16S ribosomal RNA (16S rRNA). Results SAID decreased ruminal and fecal pH and increased the propionate, butyrate and total volatile fatty acid (TVFA) concentration in feces when compared with the COD. A barcoded DNA pyrosequencing method was used to generate 2116 16S operational taxonomic units (OTUs). A total of 11 phyla were observed, distributed amongst all cattle on both diets; however, only 5 phyla were observed in all animals regardless of dietary treatment, and considerable animal to animal variation was revealed. The average abundance and its range of the 5 phyla were as follows: Firmicutes (63.7%, 29.1–84.1%), Proteobacteria (18.3%, 3.4–46.9%), Actinobacteria (6.8%, 0.4–39.9%), Bacteroidetes (7.6%, 2.2–17.7%) and Tenericutes (1.6%, 0.3–3%). Feeding the SAID resulted in significant shifts in the structure of the fecal microbial community when compared with the traditional COD. Among the 2116 OTUs detected in the present study, 88 OTUs were affected significantly by diet; and the proportion of these OTUs was 20.6% and 17.4% among the total number of sequences, respectively. Among the OTUs affected, the predominant species, including OTU2140 (G: Turicibacter), OTU1695 (G: Stenotrophomonas) and OTU8143 (F: Lachnospiraceae), were increased, while the abundance of OTU1266 (S: Solibacillus silvestris) and OTU2022 (G: Lysinibacillus) was reduced in the SAID group compared with the COD. Further, our results indicated that the fecal volatile fatty acid (VFA) concentrations were significantly related to presence of some certain species of Bacteroidetes and Firmicutes in the feces. Conclusions This is, to our knowledge, the first study that has used barcoded DNA pyrosequencing to survey the fecal microbiome of dairy cattle during SARA. Our results suggest that particular bacteria and their metabolites in the feces appear to contribute to differences in host health between those given SAID and traditional COD feeding. A better understanding of these microbial populations will allow for improved nutrient management and increased animal growth performance.
    Full-text · Article · Dec 2012 · BMC Veterinary Research
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