A sensitive and easy-to-perform dipstick immunoassay to detect Escherichia coli O157:H7 in retail ground beef was developed by using a sandwich-type assay (with a polyclonal antibody to E. coli O157 as the capture antibody and a monoclonal antibody to E. coli O157:H7 as the detection antibody) on a hydrophobic polyvinylidine difluoride-based membrane. E. coli O157:H7 in ground beef could be det...

Surface water and groundwater are continuously used as sources of drinking water in many metropolitan areas of the United States. The quality of water from these sources may be reduced due to increases in contaminants such as Escherichia coli from urban and agricultural runoffs. In this study, a multiplex fluorogenic PCR assay was used to quantify E. coli O157:H7 in soil, manure, cow and calf f...

AIMS To determine if thyroid function affects faecal shedding of Escherichia coli O157:H7. METHODS AND RESULTS Eight yearling cattle (n = 4 per treatment group), previously identified as shedding E. coli O157:H7, received either 0 or 10 mg 6-N-propyl-2-thiouracil (PTU) kg(-1) BW day(-1) for 14 days to reduce serum concentrations of the thyroid hormones, T(3) and T(4). Animals were monitored d...

Studies were conducted to evaluate fecal shedding of Escherichia coli O157:H7 in a small group of inoculated deer, determine the prevalence of the bacterium in free-ranging white-tailed deer, and elucidate relationships between E. coli O157:H7 in wild deer and domestic cattle at the same site. Six young, white-tailed deer were orally administered 10(8) CFU of E. coli O157:H7. Inoculated deer we...

In a previous study, the seasonal prevalence was reported for stx+ Escherichia coli O157:H7 in feces and on hides and carcasses of cattle at processing. Overall, 1,697 O157:H7 isolates have now been characterized for the incidence of (i) eae(O157), hlyA, stx1, and stx2 in the recovered isolates and (ii) presumptive rough and presumptive nonmotile isolates. Seven O157:H7 isolates (0.4%) lacked s...

A modified version of sorbitol MacConkey medium containing cefixime and tellurite (CT-SMAC medium) was produced by adding salicin and 4-methylumbelliferyl-beta-D-galactopyranoside to CT-SMAC medium; this medium was designated CT-SSMAC medium and was used to isolate Escherichia coli O157:H7 from radish sprouts. Of 101 non-E. coli bacteria isolated from radish sprouts that produced colorless colo...

Acid resistance of Escherichia coli O157:H7 strains UT 10 and UT 15 were determined in traditional Amasi fermented for 3 days at ambient temperature (ca 30 degrees C) and commercial Amasi fermented at 30 degrees C for 24h and stored at 7 degrees C for 2 days. Escherichia coli O157:H7 counts in commercial Amasi were detected at 2.7 log(10)cfu/ml after 3 days while those in traditional Amasi coul...

The transmission of Escherichia coli O157:H7 from manure-contaminated soil and irrigation water to lettuce plants was demonstrated using laser scanning confocal microscopy, epifluorescence microscopy, and recovery of viable cells from the inner tissues of plants. E. coli O157:H7 migrated to internal locations in plant tissue and was thus protected from the action of sanitizing agents by virtue ...

Hide has been established as the main source of carcass contamination during cattle processing; therefore, it is crucial to minimize the amount of Escherichia coli O157:H7 on cattle hides before slaughter. Several potential sources of E. coli O157: H7 are encountered during transportation and in the lairage environment at beef-processing facilities that could increase the prevalence and numbers...

Silica coated silver (Ag@SiO2) nanoparticles were prepared and characterized by transmission electron microscope (TEM) and UV-vis absorption, and the nanoparticles were used as labels in sandwich-type immunosensor of Escherichia coli O157:H7 (E. coli O157:H7). The labels involved in immunoreaction were dissolved by mixed acid of hydrofluoric acid and nitric acid, and the released Ag(+) ions wer...