ABSTRACT
This study was conducted to identify the origin of Escherichia coli O157:H7 contamination on steer hides at the time of harvest. Samples were collected from the feedlot, transport trailers, and packing plant holding pens and from the colons and hides of feedlot steers. A total of 50 hide samples were positive for E. coli O157:H7 in two geographical locations: the Midwest (25 positive hides) and Southwest (25 positive hides). Hide samples were screened, and the presence of E. coli O157: H7 was confirmed. E. coli O157:H7 isolates were fingerprinted by pulsed-field gel electrophoresis and subjected to multiplex PCR procedures for amplification of E. coli O157:H7 genes stx1, stx2, eaeA, fliC, rfbEO157, and hlyA. Feedlot water trough, pen floor, feed bunk, loading chute, truck trailer side wall and floor, packing plant holding pen floor and side rail, and packing plant cattle drinking water samples were positive for E. coli O157:H7. Pulsed-field gel electrophoresis banding patterns were analyzed after classifying isolates according to the marker genes present and according to packing plant. In this study, hide samples positive for E. coli O157:H7 were traced to other E. coli O157:H7-positive hide, colon, feedlot pen floor fecal, packing plant holding pen drinking water, and transport trailer side wall samples. Links were found between packing plant side rails, feedlot loading chutes, and feedlot pens and between truck trailer, different feedlots, and colons of multiple cattle. This study is the first in which genotypic matches have been made between E. coli O157:H7 isolates obtained from transport trailer side walls and those from cattle hide samples within the packing plant.
Subject(s)
Animal Husbandry/standards , Cattle Diseases/microbiology , DNA, Bacterial/analysis , Escherichia coli Infections/veterinary , Escherichia coli O157/isolation & purification , Skin/microbiology , Animals , Bacterial Typing Techniques , Cattle , Cattle Diseases/epidemiology , Colony Count, Microbial , Electrophoresis, Gel, Pulsed-Field , Environmental Microbiology , Escherichia coli Infections/epidemiology , Escherichia coli Infections/microbiology , Escherichia coli O157/genetics , Floors and Floorcoverings , Food Contamination , Food Microbiology , Gene Amplification , Hair/microbiology , Housing, Animal , Male , Polymerase Chain ReactionABSTRACT
A glial fibrillary acidic protein (GFAP) fluorescent enzyme linked immunosorbant assay (ELISA) was compared with an ELISA test kit for GFAP to determine the level of central nervous system (CNS) tissue in advanced meat recovery (AMR) products. The test kit results were highly correlated (r=0.975) with the fluorescent ELISA. Meat cuts and AMR were analyzed on site at 14 meat plants utilizing the test kits. In seven of the plants all AMR samples had less than 1 ng GFAP. Seven of the plants had greater than 1 ng GFAP in AMR samples. Development of proper process controls to eliminate inclusion of spinal cord in AMR materials should bring all values to less than 1 ng GFAP, a level slightly above background.
ABSTRACT
We report the development and validation of a fluorescent enzyme-linked immunosorbent assay (ELISA) for glial fibrillary acidic protein (GFAP), which can be used as a rapid and sensitive method to detect CNS tissue in meat products. The fluorometric assay is sensitive to 0.2 ng GFAP and has an intra-assay coefficient of variation (CV) of 2.0% and an interassay CV of 14.1%. Bovine spinal cord and brain demonstrate dose-response curves that are parallel to GFAP standards, whereas peripheral sciatic nerve and cervical ganglia also cross-react at high tissue levels. The use of another central nervous system marker, syntaxin 1-B, was not effective for neural tissue detection. Less than 1.0 ng GFAP per mg tissue was found on most beef subprimals and advanced meat recovery (AMR) product. Occasional samples contained higher levels of GFAP, probably because of contamination by the carcass-splitting saw, incomplete removal of the spinal cord, or a chance sampling of a major nerve. Further reduction of CNS content was facilitated by removal of the cervical vertebrae and the spinal canal prior to processing beef chuck bones through AMR equipment. The presence of GFAP was very low (0.037 ng/mg) in beef patties collected from major processors throughout the USA. The presence of normal sausage ingredients or heating the product to 80 degrees C for 60 min did not affect the detection of GFAP. Heating the product to 115 degrees C for 100 min eliminated the detectability of GFAP.
Subject(s)
Enzyme-Linked Immunosorbent Assay/methods , Glial Fibrillary Acidic Protein/analysis , Meat Products/analysis , Meat/analysis , Animals , Cattle , Fluorescence , Food Contamination/analysis , Food Handling/methods , Glial Fibrillary Acidic Protein/isolation & purification , Reproducibility of Results , Sensitivity and SpecificityABSTRACT
OBJECTIVE: To study the safe use of Dilapan at term for ripening the unfavorable cervix in an outpatient setting. STUDY DESIGN: Prospective review of cervical ripening with Dilapan in women at term gestation. Such women were assigned to either outpatient or inpatient cervical ripening with Dilapan. RESULTS: Twenty-one patients were assigned to each group. The length of induction was similar between women who had ambulatory cervical ripening and hospitalized patients (11 +/- 7 vs. 14 +/- 7 hours, respectively), and the rates of chorioamnionitis, endometritis and nonreassuring fetal heart rate tracings were also similar. However, the average length of hospitalization was significantly shorter for those who had ambulatory ripening as compared to those who were hospitalized (51 +/- 27 vs. 70 +/- 20 hours, respectively; P < .0007). CONCLUSION: The use of Dilapan for cervical ripening at term in an ambulatory setting is safe and effective and may decrease the overall hospitalization time and cost.
