scholarly journals Interlaboratory Evaluation of the U.S. Food and Drug Administration Escherichia coli Identification Microarray for Profiling Shiga Toxin–Producing Escherichia coli

2018 ◽  
Vol 81 (8) ◽  
pp. 1275-1282 ◽  
Author(s):  
ISHA R. PATEL ◽  
JAYANTHI GANGIREDLA ◽  
DAVID W. LACHER ◽  
MARK K. MAMMEL ◽  
LORI BAGI ◽  
...  
Keyword(s):  
Escherichia Coli ◽  
Quality Assurance ◽  
Drug Administration ◽  
Shiga Toxin ◽  
Food And Drug Administration ◽  
External Quality Assurance ◽  
External Quality ◽  
E Coli ◽  
Molecular Serotyping ◽  
The U.S

ABSTRACT The U.S. Food and Drug Administration Escherichia coli Identification (FDA-ECID) microarray provides rapid molecular characterization of E. coli. The effectiveness of the FDA-ECID for characterizing Shiga toxin–producing E. coli (STEC) was evaluated by three federal laboratories and one reference laboratory with a panel of 54 reference E. coli strains from the External Quality Assurance program. Strains were tested by FDA-ECID for molecular serotyping (O and H antigens), Shiga toxin subtyping, and the presence of the ehxA and eae genes for enterohemolysin and intimin, respectively. The FDA-ECID O typing was 96% reproducible among the four laboratories and 94% accurate compared with the reference External Quality Assurance data. Discrepancies were due to the absence of O41 target loci on the array and to two pairs of O types with identical target sequences. H typing was 96% reproducible and 100% accurate, with discrepancies due to two strains from one laboratory that were identified as mixed by FDA-ECID. Shiga toxin (Stx) type 1 subtyping was 100% reproducible and accurate, and Stx2 subtyping was 100% reproducible but only 64% accurate. FDA-ECID identified most Stx2 subtypes but had difficulty distinguishing among stx2a, stx2c, and stx2d genes because of close similarities of these sequences. FDA-ECID was 100% effective for detecting ehxA and eae and accurately subtyped the eae alleles. This interlaboratory study revealed that FDA-ECID for STEC characterization was highly reproducible for molecular serotyping, stx and eae subtyping, and ehxA detection. However, the array was less useful for distinguishing among the highly homologous O antigen genes and the stx2a, stx2c, and stx2d subtypes.

scholarly journals Improved Laboratory Enrichment for Enterohemorrhagic Escherichia coli by Exposure to Extremely Acidic Conditions

2004 ◽  
Vol 70 (2) ◽  
pp. 1226-1230 ◽  
Author(s):  
Michael A. Grant
Keyword(s):  
Escherichia Coli ◽  
Drug Administration ◽  
Standard Method ◽  
Food And Drug Administration ◽  
Food Samples ◽  
Enterohemorrhagic Escherichia Coli ◽  
E Coli ◽  
Enrichment Protocol ◽  
Acidic Conditions ◽  
Administration Procedure

ABSTRACT Analysis of food samples for E. coli O157:H7 using the standard U.S. Food and Drug Administration procedure is frequently complicated by overgrowth of nontarget microorganisms. A new procedure was developed for enrichment of enterohemorrhagic E. coli (EHEC) which utilizes exposure to pH 2.00 for 2 h. This procedure yielded larger populations of EHEC than the standard method by factors ranging from 2.7 to 7.7 and, when age-stressed cultures were used, by factors ranging from 2.7 to 11.5. Cultures of competing enterics were more effectively inhibited by the new enrichment protocol as well.

scholarly journals Presence of Escherichia coli O157 and O157:H7 in raw milk and Van herby cheese

2015 ◽  
Vol 59 (4) ◽  
pp. 511-514 ◽  
Author(s):  
Yakup Can Sancak ◽  
Hakan Sancak ◽  
Ozgur Isleyici
Keyword(s):  
Public Health ◽  
Escherichia Coli ◽  
Drug Administration ◽  
Shiga Toxin ◽  
Raw Milk ◽  
Escherichia Coli O157 ◽  
Human Pathogens ◽  
Emerging Pathogens ◽  
E Coli ◽  
Milk Samples

Abstract The Shiga toxin-producing Escherichia coli (STEC) strains are currently considered important emerging pathogens threatening public health. Among Shiga toxin-producing Escherichia coli, E. coli O157:H7 strains have emerged as important human pathogens. This study was conducted to determine the presence of Escherichia coli O157 and O157:H7 in raw milk samples and Van herby cheese samples. For this purpose, 100 samples of raw milk were collected and 100 samples of herby cheese sold for consumption in Van province in Turkey were obtained from grocers and markets in order to detect the presence of Escherichia coli O157 and O157:H7. The method of E. coli O157 and O157:H7 isolation proposed by the Food and Drug Administration (FDA) was used. E. coli O157 in raw milk and herby cheese samples was found in 11% and 6% of samples respectively, and E. coli O157:H7 was found in 2% of herby cheese samples. No E. coli O157:H7 was detected in raw milk samples. This study showed that raw milk was contaminated with E. coli O157 and herby cheese was contaminated with both E. coli O157 and E. coli O157:H7; therefore, herby cheese poses a serious risk to public health.

scholarly journals Public oversight of the audit profession – Comparison of implemented practices in the EU and the U.S.

2014 ◽  
Vol 7 (3) ◽  
Author(s):  
Maja Zaman Groff ◽  
Marko Hočevar
Keyword(s):  
Quality Assurance ◽  
External Quality Assurance ◽  
External Quality ◽  
The Public ◽  
Sarbanes Oxley ◽  
The Impact ◽  
Public Oversight ◽  
The U.S ◽  
The Eu

Following financial scandals at the turn of the century, the audit profession in the European Union, the United States and elsewhere, has undergone profound legislative and regulatory reforms, including the requirement for intense public oversight of the profession. The article provides an overview of the development of external quality assurance systems in the audit profession in the EU and the U.S. with emphasis on the system of public oversight, implemented after the passing of the Sarbanes-Oxley Act of 2002 in the U.S. and the Statutory Audit Directive of 2006 in the EU. The aims of the article are: 1) to explain different backgrounds of external quality assurance systems in the EU and the U.S., 2) to describe implemented practices related to the public oversight system in the two regions and 3) to present the main findings of the existing empirical research focusing on the impact of the newly established systems of public oversight on the quality of audit services. Our literature research reveals that the evidence on the impact of the public oversight on the ultimate audit quality in the EU has not yet been provided because the Member States have only finished the implementation of the Statutory Audit Directive requirements into national legislations by the year 2008. In the U.S., on the other hand, first empirical evidence has been presented, suggesting that the quality of auditing has improved after the passing of the Sarbanes Oxley Act of 2002. So far evidence has been provided to support the proposition that PCAOB opinions are associated with earnings quality of the audit firm’s clients, that auditors have become more conservative and that the new inspectors (as opposed to the former system of self-regulation) can hold the auditors to stricter standards by taking concrete actions against felonious auditors and imposing costly penalties.

Bacteriological Method for the Examination of Tree Nut Meats

1968 ◽  
Vol 51 (4) ◽  
pp. 867-869
Author(s):  
John M Lanier
Keyword(s):  
Escherichia Coli ◽  
Drug Administration ◽  
Food And Drug Administration ◽  
Collaborative Study ◽  
Bacteriological Examination ◽  
E Coli ◽  
Tree Nut ◽  
Bacteriological Method ◽  
Plate Counts

Abstract A collaborative study was made of a method used by the Food and Drug Administration for the bacteriological examination of tree nut meats. The method is based on enumeration and identification of Escherichia coli and on aerobic plate counts. Collaborative recoveries of E. coli were considered satisfactory, and the method is recommended for adoption as official, first action. The method for determining aerobic plate counts will be further studied.

scholarly journals Novel Microarray Design for Molecular Serotyping of Shiga Toxin-Producing Escherichia coli Strains Isolated from Fresh Produce

2014 ◽  
Vol 80 (15) ◽  
pp. 4677-4682 ◽  
Author(s):  
David W. Lacher ◽  
Jayanthi Gangiredla ◽  
Scott A. Jackson ◽  
Christopher A. Elkins ◽  
Peter C. H. Feng
Keyword(s):  
Escherichia Coli ◽  
Shiga Toxin ◽  
Fresh Produce ◽  
Content Type ◽  
E Coli ◽  
Efficacy Analysis ◽  
Molecular Serotyping ◽  
Large Numbers ◽  
Complex Procedure ◽  
Content Identification

ABSTRACTSerotypingEscherichia coliis a cumbersome and complex procedure due to the existence of large numbers of O- and H-antigen types. It can also be unreliable, as many Shiga toxin-producingE. coli(STEC) strains isolated from fresh produce cannot be typed by serology or have only partial serotypes. The FDAE. coliidentification (FDA-ECID) microarray, designed for characterizing pathogenicE. coli, contains a molecular serotyping component, which was evaluated here for its efficacy. Analysis of a panel of 75 referenceE. colistrains showed that the array correctly identified the O and H types in 97% and 98% of the strains, respectively. Comparative analysis of 73 produce STEC strains showed that serology and the array identified 37% and 50% of the O types, respectively, and that the array was able to identify 16 strains that could not be O serotyped. Furthermore, the array identified the H types of 97% of the produce STEC strains compared to 65% by serology, including six strains that were mistyped by serology. These results show that the array is an effective alternative to serology in serotyping environmentalE. coliisolates.

Comparison of Enrichment Procedures for Shiga Toxin–Producing Escherichia coli in Wastes from Commercial Swine Farms†

2009 ◽  
Vol 72 (9) ◽  
pp. 1982-1986 ◽  
Author(s):  
MICHAEL A. GRANT ◽  
MARK A. MOGLER ◽  
DELBERT L. HARRIS
Keyword(s):  
Escherichia Coli ◽  
Drug Administration ◽  
Shiga Toxin ◽  
Swine Production ◽  
Department Of Agriculture ◽  
E Coli ◽  
Swine Farms ◽  
Heat Stable ◽  
Enrichment Procedure ◽  
Pooled Samples

Three methods for enrichment of Shiga toxin–producing Escherichia coli (STEC) were compared using waste pit samples from swine production facilities housing 50 to 3,000 animals. The STEC gene stx2 was detected in 5 of 17 pooled samples using a U.S. Department of Agriculture (USDA) enrichment procedure, 6 of 17 samples using a U.S. Food and Drug Administration (FDA) enrichment procedure, and 8 of 17 samples using an experimental acid enrichment. All isolates were non-O157 and 5 of 6 were positive for enterotoxigenic E. coli–associated heat stable toxins a and b. The three enrichment procedures were also tested for their ability to support growth of 31 strains of STEC. The acid enrichment media supported growth of 100% of the strains, the FDA medium supported 77% of the strains, and the USDA medium supported 16% of the strains.

Detection and Isolation of the “Top Seven” Shiga Toxin–Producing Escherichia coli in Ground Beef: Comparison of RapidFinder Kits to the U.S. Department of Agriculture Microbiology Laboratory Guidebook Method

2017 ◽  
Vol 80 (5) ◽  
pp. 829-836 ◽  
Author(s):  
Pina M. Fratamico ◽  
Lori K. Bagi ◽  
Aisha Abdul-Wakeel
Keyword(s):  
Escherichia Coli ◽  
Real Time ◽  
Shiga Toxin ◽  
Real Time Pcr ◽  
Ground Beef ◽  
Immunomagnetic Separation ◽  
Microbiology Laboratory ◽  
Department Of Agriculture ◽  
E Coli ◽  
The U.S

ABSTRACT Shiga toxin–producing Escherichia coli (STEC) O157:H7 and serogroups O26, O45, O103, O111, O121, and O145 are often referred to as the “top seven” STEC, and these have been declared to be adulterants in beef by the U.S. Department of Agriculture (USDA) Food Safety and Inspection Service (FSIS). The aim of this work was to compare the methods described in the USDA FSIS Microbiology Laboratory Guidebook (MLG) to a two-stage Applied Biosystems RapidFinder STEC real-time PCR method to test for the top seven STEC in raw ground beef. The specificity of the RapidFinder workflow that targets non-O157 STEC O-antigen genes, stx1, stx2, and eae, and E. coli O157–specific targets was determined with 132 top seven STEC strains and 283 exclusion strains. All inclusion strains were positive, and all exclusion strains gave negative results with the RapidFinder assay. Strains carrying all of the known variants of stx1 and stx2, including stx2f and stx2g, were also detected. For RapidFinder analysis, 375-g ground beef samples spiked with ≥4 CFU of representative STEC strains were enriched in 1 L of tryptic soy broth (TSB) for 10 h at 42 ± 1°C, and for the MLG method, 325-g samples were similarly spiked and enriched in 975 mL of modified TSB for 15 h at 42 ± 1°C. Following DNA extraction, real-time PCR was performed using RapidFinder Express software, and for the MLG method, the BAX Real-Time PCR STEC Suite and the BAX Real-Time E. coli O157:H7 assay were used with the BAX System Q7 software. Following immunomagnetic separation, presumptive colonies from modified Rainbow agar O157 plates were confirmed by the real-time PCR assays. Results of the RapidFinder and BAX assays were similar; all samples were positive after 10 and 15 h of enrichment, respectively. Isolation and confirmation of isolates was possible on all samples, except that two O111:NM strains could not be isolated from a portion of the inoculated samples. Thus, the RapidFinder system can be used for routine and rapid detection of the top seven STEC in beef.

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