scholarly journals Effect of Sand and Sawdust Bedding Materials on the Fecal Prevalence of Escherichia coli O157:H7 in Dairy Cows

2005 ◽  
Vol 71 (1) ◽  
pp. 326-330 ◽  
Author(s):  
Jeffrey T. LeJeune ◽  
Michael D. Kauffman
Keyword(s):  
Escherichia Coli ◽  
Dairy Cows ◽  
Management Practices ◽  
Potential Role ◽  
Dairy Farms ◽  
E Coli ◽  
Food Borne ◽  
Bedding Materials ◽  
Sand Bedding

ABSTRACT Farm management practices that reduce the prevalence of food-borne pathogens in live animals are predicted to enhance food safety. To ascertain the potential role of livestock bedding in the ecology and epidemiology of Escherichia coli O157:H7 on farms, the survival of this pathogen in used-sand and used-sawdust dairy cow bedding was determined. Additionally, a longitudinal study of mature dairy cattle housed on 20 commercial dairy farms was conducted to compare the prevalence of E. coli O157:H7 in cattle bedded on sand to that in cattle bedded on sawdust. E. coli O157:H7 persisted at higher concentrations in used-sawdust bedding than in used-sand bedding. The overall average herd level prevalence (3.1 versus 1.4%) and the number of sample days yielding any tests of feces positive for E. coli O157:H7 (22 of 60 days versus 13 of 60 days) were higher in sawdust-bedded herds. The choice of bedding material used to house mature dairy cows may impact the prevalence of E. coli O157:H7 on dairy farms.

scholarly journals Potential Role of Diploscapter sp. Strain LKC25, a Bacterivorous Nematode from Soil, as a Vector of Food-Borne Pathogenic Bacteria to Preharvest Fruits and Vegetables

2005 ◽  
Vol 71 (5) ◽  
pp. 2433-2437 ◽  
Author(s):  
Daunte S. Gibbs ◽  
Gary L. Anderson ◽  
Larry R. Beuchat ◽  
Lynn K. Carta ◽  
Phillip L. Williams
Keyword(s):  
Pathogenic Bacteria ◽  
Fruits And Vegetables ◽  
Potential Role ◽  
The United States ◽  
Cow Manure ◽  
Free Living ◽  
E Coli ◽  
Food Borne ◽  
Agar Media

ABSTRACT Diploscapter, a thermotolerant, free-living soil bacterial-feeding nematode commonly found in compost, sewage, and agricultural soil in the United States, was studied to determine its potential role as a vehicle of Salmonella enterica serotype Poona, enterohemorrhagic Escherichia coli O157:H7, and Listeria monocytogenes in contaminating preharvest fruits and vegetables. The ability of Diploscapter sp. strain LKC25 to survive on agar media, in cow manure, and in composted turkey manure and to be attracted to, ingest, and disperse food-borne pathogens inoculated into soil or a mixture of soil and composted turkey manure was investigated. Diploscapter sp. strain LKC25 survived and reproduced in lawns of S. enterica serotype Poona, E. coli O157:H7, and L. monocytogenes on agar media and in cow manure and composted turkey manure. Attraction of Diploscapter sp. strain LKC25 to colonies of pathogenic bacteria on tryptic soy agar within 10, 20, 30, and 60 min and 24 h was determined. At least 85% of the worms initially placed 0.5 to 1 cm away from bacterial colonies migrated to the colonies within 1 h. Within 24 h, ≥90% of the worms were embedded in colonies. The potential of Diploscapter sp. strain LKC25 to shed pathogenic bacteria after exposure to bacteria inoculated into soil or a mixture of soil and composted turkey manure was investigated. Results indicate that Diploscapter sp. strain LKC25 can shed pathogenic bacteria after exposure to pathogens in these milieus. They also demonstrate its potential to serve as a vector of food-borne pathogenic bacteria in soil, with or without amendment with compost, to the surface of preharvest fruits and vegetables in contact with soil.

scholarly journals Association of Escherichia Coli 0157:H7 in Flocs: Role of Extracellular Polymeric Substances and Fate of Pathogenic Organisms

2021 ◽  
Author(s):  
Mitsuko Kanetani
Keyword(s):  
Escherichia Coli ◽  
Extracellular Polymeric Substances ◽  
Natural Environments ◽  
Potential Mechanism ◽  
Free Living ◽  
E Coli ◽  
Adhesion Ability ◽  
Food Borne ◽  
Water Borne

In North America, Escherichia coli (E. coli) O157:H7 has been frequently associated with outbreaks of food-borne and water-borne infection. The association of E. coli O157:H7 to flocs is hypothesized to be a potential mechanism of transport and survival in natural environments. This study examines this hypothesis with a focus on the role of extracellular polymeric substances (EPS) and on E. coli O157:H7 survival/pathogenicity in an aquatic environment. The floc characterization experiment indicted that EPS play a significant role in floc stability. The EPS distribution experiment revealed abundant hydrophobic protein throughout the floc, which contributed to floc stability and microbial adhesion. In examining the survivability of E. coli O157:H7 in a low nutrient water sample for 10-day incubation, more floc-adherent E. coli O157:H7 survived than the free-living form since EPS provided protection, nutrients and stable sites for survival. Surviving E. coli O157:H7 exhibited both decreased host adhesion ability and ª-actinin accumulation; however, their infection ability was not affected. This suggests that low nutrient levels did not affect pathogenicity over 10 days in this study.

Factors Associated with Fecal Shedding of Verotoxin-Producing Escherichia coli O157 on Dairy Farms

1999 ◽  
Vol 62 (4) ◽  
pp. 307-312 ◽  
Author(s):  
L. GARBER ◽  
S. WELLS ◽  
L. SCHROEDER-TUCKER ◽  
K. FERRIS
Keyword(s):  
Escherichia Coli ◽  
Dairy Cows ◽  
Odds Ratio ◽  
Dairy Farms ◽  
Escherichia Coli O157 ◽  
Fecal Samples ◽  
Fecal Shedding ◽  
E Coli ◽  
Factors Associated

Fecal samples were collected from 4,361 dairy cows on 91 dairy operations between 26 February and 8 July 1996. Fecal samples were cultured for Escherichia coli O157, and positive isolates were probed for verotoxin-producing genes. A total of 52 (1.2%) fecal samples on 22 (24.2%) operations were positive for verotoxin-producing E. coli O157. Herds in which samples were collected on or after 1 May 1996 were significantly more likely to test positive than herds sampled before that date (odds ratio = 7.7). Herds maintained on farms on which alleyways were flushed with water to remove manure were 8.0 times more likely to have samples test positive for verotoxin-producing E. coli O157 than were herds maintained on farms cleaned by use of other methods of manure removal.

scholarly journals Prevalence and patterns of antimicrobial resistance among Escherichia coli isolated from Zambian dairy cattle across different production systems

2015 ◽  
Vol 5 (1) ◽  
Author(s):  
Geoffrey Mainda ◽  
Paul R. Bessell ◽  
John B. Muma ◽  
Sean P. McAteer ◽  
Margo E. Chase-Topping ◽  
...  
Keyword(s):  
Escherichia Coli ◽  
Antibiotic Resistance ◽  
Random Sample ◽  
Management Practices ◽  
Production Systems ◽  
Farming Systems ◽  
Dairy Farms ◽  
Antibiotic Use ◽  
Farm Size ◽  
E Coli

Abstract This study focused on the use of antibiotics on small, medium and commercial-sized dairy farms in the central region of Zambia and its relationship to antibiotic resistance in Escherichia coli. A stratified random sample of 104 farms was studied, representing approximately 20% of all dairy farms in the region. On each farm, faecal samples were collected from a random sample of animals and a standardised questionnaire on the usage of antibiotics was completed. An E. coli isolate was obtained from 98.67% (371/376) of the sampled animals and tested for resistance to six classes of antibiotics. The estimated prevalence of resistance across the different farming systems was: tetracycline (10.61; 95%CI: 7.40–13.82), ampicillin (6.02; 95%CI: 3.31–8.73), sulfamethoxazole/ trimethoprim (4.49; 95%CI: 2.42–6.56), cefpodoxime (1.91; 95%CI: 0.46–3.36), gentamicin (0.89; 95%CI: 0.06–1.84) and ciprofloxacin (0%). Univariate analyses indicated certain diseases, exotic breeds, location, farm size and certain management practices as risk factors for detection of resistance, whereas multivariate analyses showed an association with lumpy skin disease and a protective effect for older animals (>25 months). This study has provided novel insights into the drivers of antibiotic use and their association with antibiotic resistance in an under-studied region of Southern Africa.

Prevalence and Characteristics of Strains of Escherichia coli Isolated from Milk and Feces of Cows on Dairy Farms in Trinidad

1997 ◽  
Vol 60 (10) ◽  
pp. 1174-1181 ◽  
Author(s):  
A. A. ADESIYUN ◽  
L. A. WEBB ◽  
H. ROMAIN ◽  
J. S. KAMINJOLO
Keyword(s):  
Escherichia Coli ◽  
Dairy Cows ◽  
Dairy Farms ◽  
Microbial Quality ◽  
E Coli ◽  
Milk Samples ◽  
Bulk Milk ◽  
Quality Of Water ◽  
The Difference

The prevalence, counts, and characteristics of Escherichia coli isolated from bulk milk, composite milk, and feces of dairy cows in eight milking centers were determined. The microbial quality of water used during milking was also investigated. Of a total of 175 bulk milk samples studied, 83 (47.4%) contained E. coli compared to only 14 (4.9%) of 287 composite milk samples and the difference was statistically significant (P ≤ 0.001; χ2). The ranges in mean counts of E. coli per milliliter of bulk milk and composite milk were 8.4 × 103 to 2.0 × 105 and 2.1 × 101 to 2.0 × 102, respectively. The prevalences and mean counts of E. coli and mean pH values for bulk milk from farms with and without subclinically mastitic cows were not significantly different (P ≥ 0.05; χ2). A total of 204 (65.2%) of 313 fecal samples of dairy cows were positive for E. coli. Of the samples of water used during milking collected from 171 dairy farms, 80 (46.8%) were free of coliforms while 59 (34.5%), 12 (7.0%), and 8 (4.7%) had ranges of coliform counts per 100 ml of 1 to 50, 51 to 100, and over 250, respectively. Twenty-six (27.7%) and 17 (18.5%) of 94 strains of E. coli isolated from bulk milk were enteropathogenic E. coli (EPEC) and verocytotoxigenic E. coli (VTEC) strains, respectively. Compared with 204 fecal strains of E. coli, 16 (7.8%) and 68 (35.6%) were EPEC and VTEC strains, respectively, and the differences were statistically significant (P ≤ 0.01; χ2). Similarly, the difference in prevalence of resistance to one or more of nine antimicrobial agents between bulk milk isolates (69.6%) and fecal isolates (25.9%) was statistically significant (P ≤ 0.001; χ2), and resistance to ampicillin was the most prevalent type of resistance for strains of E. coli from bulk milk isolates. It was concluded that the relatively high counts of toxigenic E. coli in bulk milk originating from dairy farms in Trinidad could pose a health risk to consumers. The poor microbial quality of water used on farms may be an important source of contamination of milk.

scholarly journals Association of Escherichia Coli 0157:H7 in Flocs: Role of Extracellular Polymeric Substances and Fate of Pathogenic Organisms

2021 ◽  
Author(s):  
Mitsuko Kanetani
Keyword(s):  
Escherichia Coli ◽  
Extracellular Polymeric Substances ◽  
Natural Environments ◽  
Potential Mechanism ◽  
Free Living ◽  
E Coli ◽  
Adhesion Ability ◽  
Food Borne ◽  
Water Borne

In North America, Escherichia coli (E. coli) O157:H7 has been frequently associated with outbreaks of food-borne and water-borne infection. The association of E. coli O157:H7 to flocs is hypothesized to be a potential mechanism of transport and survival in natural environments. This study examines this hypothesis with a focus on the role of extracellular polymeric substances (EPS) and on E. coli O157:H7 survival/pathogenicity in an aquatic environment. The floc characterization experiment indicted that EPS play a significant role in floc stability. The EPS distribution experiment revealed abundant hydrophobic protein throughout the floc, which contributed to floc stability and microbial adhesion. In examining the survivability of E. coli O157:H7 in a low nutrient water sample for 10-day incubation, more floc-adherent E. coli O157:H7 survived than the free-living form since EPS provided protection, nutrients and stable sites for survival. Surviving E. coli O157:H7 exhibited both decreased host adhesion ability and ª-actinin accumulation; however, their infection ability was not affected. This suggests that low nutrient levels did not affect pathogenicity over 10 days in this study.

Canadian Perspectives on Verocytotoxin-Producing Escherichia coli Infection†

1997 ◽  
Vol 60 (11) ◽  
pp. 1451-1453 ◽  
Author(s):  
JEFFREY B. WILSON ◽  
ROGER P. JOHNSON ◽  
ROBERT C. CLARKE ◽  
KRIS RAHN ◽  
SHANE A. RENWICK ◽  
...  
Keyword(s):  
Escherichia Coli ◽  
Management Practices ◽  
Dairy Farms ◽  
Case Control Studies ◽  
Traditional Management ◽  
Farm Level ◽  
E Coli ◽  
Effective Strategies ◽  
Rural Environments ◽  
Escherichia Coli Infection

Infection with verocytotoxin-producing Escherichia coli (VTEC) became nationally reportable in 1990. Between 1990 and 1994, the national incidence of reported infections ranged from 3 to 5.3 per 100,000 inhabitants. Most cases are sporadic and are caused by E. coli O157:H7. Recent investigations have identified that, in addition to exposure to undercooked ground beef, contact with cattle, consumption of well water, and exposure to rural environments are important risk factors for VTEC infection. Also, results of case control studies and detection of asymptomatic fecal carriage of E. coli O157:H7 and other VTEC in farm family members and abattoir workers have led to an increasing emphasis on person-to-person spread in the epidemiology of VTEC infection. Controlling E. coli O157:H7 and other VTEC at the farm level may therefore have a broader impact than simply reducing the risk of foodborne VTEC infection. Longitudinal studies on dairy farms have demonstrated that E. coli O157:H7 carriage by cattle at the farm and animal level is often transient, and that cattle, rather than the farm environment, are the major reservoir for this organism on dairy farms. Small herds that are controlled by traditional management practices have the highest risk for VTEC infection. Further studies are likely to result in development of effective strategies to control VTEC at the farm level.

scholarly journals Roles of the C-Terminal Amino Acids of Non-Hexameric Helicases: Insights from Escherichia coli UvrD

2021 ◽  
Vol 22 (3) ◽  
pp. 1018
Author(s):  
Hiroaki Yokota
Keyword(s):  
Escherichia Coli ◽  
Amino Acids ◽  
Amino Acid ◽  
Single Molecule ◽  
Underlying Mechanism ◽  
Amino Acid Sequences ◽  
E Coli ◽  
X Ray Crystallography ◽  
Terminal Amino

Helicases are nucleic acid-unwinding enzymes that are involved in the maintenance of genome integrity. Several parts of the amino acid sequences of helicases are very similar, and these quite well-conserved amino acid sequences are termed “helicase motifs”. Previous studies by X-ray crystallography and single-molecule measurements have suggested a common underlying mechanism for their function. These studies indicate the role of the helicase motifs in unwinding nucleic acids. In contrast, the sequence and length of the C-terminal amino acids of helicases are highly variable. In this paper, I review past and recent studies that proposed helicase mechanisms and studies that investigated the roles of the C-terminal amino acids on helicase and dimerization activities, primarily on the non-hexermeric Escherichia coli (E. coli) UvrD helicase. Then, I center on my recent study of single-molecule direct visualization of a UvrD mutant lacking the C-terminal 40 amino acids (UvrDΔ40C) used in studies proposing the monomer helicase model. The study demonstrated that multiple UvrDΔ40C molecules jointly participated in DNA unwinding, presumably by forming an oligomer. Thus, the single-molecule observation addressed how the C-terminal amino acids affect the number of helicases bound to DNA, oligomerization, and unwinding activity, which can be applied to other helicases.

scholarly journals Distribution of Lactoferrin Is Related with Dynamics of Neutrophils in Bacterial Infected Mice Intestine

Molecules ◽  
2020 ◽  
Vol 25 (7) ◽  
pp. 1496 ◽  
Author(s):  
Li Liang ◽  
Zhen-Jie Wang ◽  
Guang Ye ◽  
Xue-You Tang ◽  
Yuan-Yuan Zhang ◽  
...  
Keyword(s):  
Escherichia Coli ◽  
Antimicrobial Activity ◽  
Mucosal Immunity ◽  
Mrna Levels ◽  
Iron Binding ◽  
E Coli ◽  
New Knowledge ◽  
Activated Neutrophils ◽  
Binding Glycoprotein

Lactoferrin (Lf) is a conserved iron-binding glycoprotein with antimicrobial activity, which is present in secretions that recover mucosal sites regarded as portals of invaded pathogens. Although numerous studies have focused on exogenous Lf, little is known about its expression of endogenous Lf upon bacterial infection. In this study, we investigated the distribution of Lf in mice intestine during Escherichia coli (E. coli) K88 infection. PCR and immunohistology staining showed that mRNA levels of Lf significantly increased in duodenum, ileum and colon, but extremely decreased in jejunum at 8 h and 24 h after infection. Meanwhile, endogenous Lf was mostly located in the lamina propria of intestine villi, while Lf receptor (LfR) was in the crypts. It suggested that endogenous Lf-LfR interaction might not be implicated in the antibacterial process. In addition, it was interesting to find that the infiltration of neutrophils into intestine tissues was changed similarly to Lf expression. It indicated that the variations of Lf expression were rather due to an equilibrium between the recruitment of neutrophils and degranulation of activated neutrophils. Thus, this new knowledge will pave the way to a more effective understanding of the role of Lf in intestinal mucosal immunity.

SATP (YaaH), a succinate–acetate transporter protein in Escherichia coli

2013 ◽  
Vol 454 (3) ◽  
pp. 585-595 ◽  
Author(s):  
Joana Sá-Pessoa ◽  
Sandra Paiva ◽  
David Ribas ◽  
Inês Jesus Silva ◽  
Sandra Cristina Viegas ◽  
...  
Keyword(s):  
Escherichia Coli ◽  
Acetic Acid ◽  
Succinic Acid ◽  
Critical Role ◽  
Amino Acid Residues ◽  
E Coli ◽  
Transporter Protein ◽  
Affinity Constants ◽  
In Trans

In the present paper we describe a new carboxylic acid transporter in Escherichia coli encoded by the gene yaaH. In contrast to what had been described for other YaaH family members, the E. coli transporter is highly specific for acetic acid (a monocarboxylate) and for succinic acid (a dicarboxylate), with affinity constants at pH 6.0 of 1.24±0.13 mM for acetic acid and 1.18±0.10 mM for succinic acid. In glucose-grown cells the ΔyaaH mutant is compromised for the uptake of both labelled acetic and succinic acids. YaaH, together with ActP, described previously as an acetate transporter, affect the use of acetic acid as sole carbon and energy source. Both genes have to be deleted simultaneously to abolish acetate transport. The uptake of acetate and succinate was restored when yaaH was expressed in trans in ΔyaaH ΔactP cells. We also demonstrate the critical role of YaaH amino acid residues Leu131 and Ala164 on the enhanced ability to transport lactate. Owing to its functional role in acetate and succinate uptake we propose its assignment as SatP: the Succinate–Acetate Transporter Protein.

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