Detection and isolation of low levels of E. coli O157:H7 in cilantro by real-time PCR, immunomagnetic separation, and cultural methods with and without an acid treatment.

Unlabelled: Leafy greens such as cilantro, contaminated with Escherichia coli O157:H7, have been implicated in cases of human illnesses. High levels of microflora in fresh cilantro make recovery of low numbers of E. coli O157:H7 difficult.

Efficacy of a post enrichment acid treatment for isolation of Escherichia coli O157:H7 from alfalfa sprouts.

The enrichment, detection and isolation procedure in the current US FDA BAM have been shown effective for Escherichia coli O157:H7 in a wide variety of foods. Recently reported modifications to the enrichment protocol, including post-enrichment immunomagnetic separation (IMS) procedures have improved sensitivity of the method for alfalfa sprouts. However, cultural isolation on selective agar plates still presents a challenge in this food matrix.

Optimization and evaluation of a modified enrichment procedure combined with immunomagnetic separation for detection of E. coli O157:H7 from artificially contaminated alfalfa sprouts.

Escherichia coli O157:H7 has been linked to foodborne disease outbreaks with alfalfa sprouts. Detection of the organism in sprouts by standard cultural methods can be difficult due to the high background microflora. The objective of this study was to develop and optimize an enrichment protocol with and without post-enrichment immunomagnetic separation (IMS) for the rapid detection by real-time PCR (RTiPCR) and cultural recovery of E.

Detection of E. coli O157:H7 in raw ground beef by Pathatrix™ immunomagnetic-separation, real-time PCR and cultural methods.

Detection of Escherichia coli O157:H7 by conventional cultural methods can be difficult in food matrices with a high background flora such as raw ground beef. Raw ground beef samples, artificially contaminated separately with five strains of E. coli O157:H7 at low (~0.

A new chromogenic agar medium for detection of potentially virulent Yersinia enterocolitica.

Several outbreaks of foodborne yersiniosis have been documented and this disease continues to be source of infections transmitted through foods. The selective agars most commonly used to isolate Yersinia enterocolitica in clinical, food and environmental samples, cefsulodin-irgasan-novobiocin (CIN) and MacConkey (MAC) agars, lack the ability to differentiate potentially virulent Y. enterocolitica from other Yersinia that may be present as well as some other bacterial spp.

Detection of Shiga toxin genes stx1, stx2, and the +93 uidA mutation of E. coli O157:H7/H-using SYBR Green I in a real-time multiplex PCR.

Enterohemorrhagic Escherichia coli (EHEC) is a major foodborne pathogen capable of causing diarrhea and vomiting, but more serious complications such as hemorrhagic colitis and hemolytic-uremic syndrome (HUS) can result. A real-time PCR method to detect the presence of Shiga toxin producing E. coli (STEC) and E.

Optimization of a 3'-minor groove binder-DNA probe targeting the uidA gene for rapid identification of Escherichia coli O157:H7 using real-time PCR.

Enterohemorrhagic Escherichia coli are harmful human pathogens capable of causing bloody diarrhea and vomiting. An important serotype commonly associated with human illness is the E. coli O157:H7 serotype.

Multiplex real-time PCR method to identify Shiga toxin genes stx1 and stx2 and Escherichia coli O157:H7/H- serotype.

A multiplex real-time PCR method to simultaneously detect the stx1 and stx2 genes of Shiga toxin-producing Escherichia coli and a unique conserved single-nucleotide polymorphism in the E. coli O157:H7/H- uidA gene has been developed. There is more than 98.

Use of endogenous host plasmids for generation of Escherichia coli O157:H7 and Shigella sonnei strains that stably express the green fluorescent protein.

The gfp gene was manipulated from a commercially available, high copy vector into endogenous plasmids of Escherichia coli O157:H7 and Shigella sonnei to yield stable GFP strains that required neither high copy number for visualization nor antibiotics for stable maintenance of the phenotype. The GFP phenotype of these strains remained stable after repeated passages in media and conditions that enhance plasmid instability and loss from bacterial cells. These results demonstrate the utility of the endogenous plasmids in selectively marking bacteria without altering host cellular function or biochemical properties.

Comparison of Template Preparation Methods from Foods for Amplification of Escherichia coli O157 Shiga-Like Toxins Type I and II DNA by Multiplex Polymerase Chain Reaction.

Escherichia coli O157:H7 has been responsible for several recent food-borne outbreaks in the United States. To protect the public health, it is essential that rapid and sensitive methods be developed for detection of this pathogen in foods. Methods were compared for preparation of template DNA for the polymerase chain reaction (PCR) from enrichments of food homogenates seeded with E.

An Improved Rapid Technique for Isolation of Escherichia coli O157:H7 from Foods.

A newly revised enrichment and agar-plating system was tested for selectivity and sensitivity in recovery of unstressed and cold-stressed Escherichia coli O157:H7 from foods. Various foods inoculated with known levels of enterohemorrhagic E. coli O157:H7 (EHEC) were tested by enrichment for 6 h at 37°C in modified tryptic soy broth (mTSB) base supplemented with vancomycin, cefsulodin and cefixime, referred to as EHEC enrichment broth (EEB).

Survival of Escherichia coli O157:H7 in Mayonnaise and Mayonnaise-Based Sauces at Room and Refrigerated Temperatures.

Three Escherichia coli Ol57:H7 (EHEC) strains were inoculated separately into portions of commercially prepared mayonnaise held at 25 or 7°C, then examined periodically for survival of detectable EHEC. Four mayonnaise-based sauces including: a) mayonnaise-mustard sauce, b) blue cheese dressing, c) thousand island dressing and d) seafood sauce, were each inoculated with one EHEC strain. Samples of these sauces were held at 5°C, and assayed periodically for survival of detectable EHEC.

Survival of Listeria monocytogenes in Mozzarella Cheese and Ice Cream Exposed to Gamma Irradiation.

The survival of Listeria monocytogenes preinoculated into ice cream and mozzarella cheese prior to gamma-irradiation treatment was determined. Samples were maintained at -78°C and exposed to targeted doses of 2,4,8,16, and 32 kGy of gamma-irradiation. The calculated D values were 1.

Aeromonas hydrophila in Shellfish Growing Waters: Incidence and Media Evaluation.

Levels of Aeromonas hydrophila determined for the shellfish growing area of Grays Harbor, Washington, ranged from 3 to 4600/100 g in oysters and from 3 to 2400/100 ml in water. Of isolates tested, 80% produced a hemolysin, a trait reported to correlate with enterotoxin production and pathogenicity. Two enrichment broths, Tryptic Soy Broth with ampicillin (TSBA) and Modified Rimler Shotts Broth (MRSB) were compared in combination with three solid agar media: Rimler Shotts (RS), Peptone Beef Extract Glycogen (PBG), and MacConkey's (MCA) agars.

The Incidence of Listeria Species in Frozen Seafood Products.

Samples of frozen seafood products from several countries were tested for the presence of Listeria monocytogenes and other Listeria species using the U.S. Food and Drug Administration (FDA) Listeria isolation method.

Yersiniosis Associated with Tofu Consumption: Serological, Biochemical and Pathogenicity Studies of Yersinia enterocolitica Isolates.

From December 1981 to February 1982, 87 individuals (ages two months to 74 years) in the Seattle, WA, area developed the clinical symptoms of yersiniosis. Illness was related to consumption of commercial tofu (soybean curd) contaminated with Yersinia enterocolitica . The six Y.