Research Publications (Food Safety)

Escherichia coli O157:H7 is an important foodborne pathogen and has been implicated in numerous food poisoning outbreaks worldwide. Although several microbiological and molecular methods have been developed to detect E. coli O157:H7, the difficulty to rapidly detect low levels of the foodborne bacteria persists. Here, the optimization of a filtration technique to concentrate and rapidly detect E. coli O157:H7 was conducted.

Controlling the free chlorine (FC) availability in wash water during sanitization of fresh produce enhances our ability to reduce microbial levels and prevent cross‐contamination. However, maintaining an ideal concentration of FC that could prevent the risk of contamination within the wash system is still a technical challenge in the industry, indicating the need to better understand wash water chemistry dynamics.

In Turkey, legislation reduced the salt content in fresh cheeses from 10% to 6.5% in dry matter (DM). This study investigated the effect of salt reduction on the fate of acid‐ and salt‐adapted Escherichia coli O157:H7 and Listeria monocytogenes, as well as the textural quality of recombined nonfat cheese. The cheese was manufactured using milk protein concentrate (85% protein) and skim milk powder (35% protein).

ABSTRACT

Author(s): Alejandra Orihuel, Lucrecia Terán, Jenny Renaut, Sébastien Planchon, María Pía Valacco, Emilse Masias, Carlos Minahk, Graciela Vignolo, Silvia Moreno, André M. De Almeida, Lucila Saavedra, Silvina Fadda

Author(s): Gökhan Kürşad Incili, Ahmet Koluman, Ayşegül Aktüre, Ahmet Ataşalan

Aims To investigate the effects of ohmic heating (OH) and water bath heating (WB) on the membrane permeability, membrane structure, intracellular organization and leakage of intracellular substances of Escherichia coli O157:H7 at the same inactivation level and at a heating temperature of 72°C. Methods and Results Flow cytometry analysis indicated that membrane permeability of E. coli O157:H7 by OH was comparable to WB at 72°C.

Aims The aim of this study was to evaluate the microbiological quality of commercially prepared RTE sushi by enumerating aerobic mesophilic bacteria (AMB) and thermotolerant coliforms (TC) and detecting Escherichia coli and Salmonella spp. An isolate was identified as E. coli O157:H7 which was evaluated for its virulence and antimicrobial resistance profiling as well as its ability to form biofilms on stainless steel.

A method combining surface‐enhanced Raman scattering (SERS) with a lateral flow strip (LFS) was developed for the quantitative and sensitive analysis of Escherichia coli O157:H7. AuMBA@Ag nanoparticles were prepared as SERS probes, and 4‐methylthiobenzoic acid (MBA) as a Raman reporter was inserted into the interior gap of the Au@Ag core‐shell nanoparticles, which replaced the Au nanoparticles that serve as SERS nanotags in traditional LFS.

Author(s): Quan Wang, MengYao Long, CaiYun Lv, SiPei Xin, XianGan Han, Wei Jiang

Author(s): Meera Surendran Nair, Fulin Ma, Patrick Lau, Indu Upadhyaya, Kumar Venkitanarayanan

Author(s): Anne-laure Moyne, Tyann Blessington, Thomas R. Williams, Steven T. Koike, Michael D. Cahn, Maria L. Marco, Linda J. Harris

Author(s): Jitendra Patel, Hsin-Bai Yin, Gary Bauchan, Joseph Mowery

A real‐time loop‐mediated isothermal amplification (Rti‐LAMP) DNA assay was developed for rapid and sensitive detection of viable Escherichia coli O157:H7 in milk by combining with ethidium monoazide bromide (EMA) and bentonite coated activated carbon (BCAC) treatment without enrichment. The assay involved inoculating 25 mL portions of milk with various numbers of E. coli O157:H7. Then each of milk sample was adsorbed with 4 g BCAC to remove DNA amplification inhibitor.

Escherichia coli O157:H7 (E coli O157:H7) is a highly virulent bacterial strain that is present in food, and as few as 10 cells can cause severe diseases. Rapid and sensitive bacterial detection is urgently required. In this study, we report a flow cytometry (FCM)‐based method for detecting E coli O157:H7 at the single‐cell level. Single E coli O157:H7 cells were obtained by a flow cytometric cell sorter and then artificially added to milk.

Cattle have been identified as a major reservoir of E. coli O157:H7 for human infection; the ecology of the organism in sheep and goats is less understood. This study was carried out to determine prevalence, sour...

Abstract

Natural microcin J25 (MccJ25) represent promising alternatives to traditional antibiotics for the treatment of drug-resistant infections. However, little is known about the antibacterial activity of recombinant MccJ25 against foodborne pathogens. Here, the activity of recombinant MccJ25 was examined using a matrix of conditions in order to assess the efficacy of recombinant MccJ25 as a mitigation against foodborne pathogens, Salmonella species and Escherichia coli (E. coli) O157.

This study investigated the microbial dynamics in multispecies biofilms of Escherichia coli O157:H7 strain 1934 (O157) or Salmonella enterica serovar Typhimurium ATCC 14028 (ST) and 40 strains of meat processing surface bacteria (MPB). Biofilms of O157 or ST with/without MPB were developed on stainless steel coupons at 15°C for up to 6 days. Bacteria in suspensions (inoculum, days 2 and 6) and biofilms (days 2 and 6) were enumerated by plating.

Abstract

Aims

To investigate the effects of ohmic heating (OH) and water bath heating (WB) on the membrane permeability, membrane structure, intracellular organization, and leakage of intracellular substances of E. coli O157:H7 at the same inactivation level and heating temperature of 72 °C.

Gold nanoflowers (GNFs) exhibit stronger light scattering ability than gold nanospheres (GNSs) with the same diameter, thereby contributing to enhancing the sensitivity of the scattering-based sensing method. However, the application of GNFs in biosensors based on dynamic light scattering (DLS) has not been yet reported. Herein, we describe for the first time an improved no-wash immunosensor based on dynamic light scattering for the detection of Escherichia coli O157:H7 (E.

Publication date: Available online 29 July 2019

Source: LWT

Author(s): Alex Tsun Yin Lau, Shai Barbut, Kelly Ross, Moussa Sory Diarra, S. Balamurugan

This study determined the prevalence, pulsed-field gel electrophoresis profiles, and antimicrobial resistance profile of Listeria monocytogenes, Salmonella enterica, and Escherichia coli O157:H7 isolates from dairy cattle farms in Jordan. Samples from bulk tank milk (n = 305), cattle feces (n = 610), and rectoanal mucosal swabs (n = 610) were collected from 61 dairy cattle farms. We confirmed 32 L. monocytogenes, 28 S. enterica, and 24 E. coli O157:H7 isolates from the samples.

The inhibitory effect of lactose oxidase on the growth of foodborne pathogens and spoilage microorganisms associated with dairy products was evaluated through an overlay inhibition assay. Lactose oxidase generates hydrogen peroxide via lactose oxidation into lactobionic acid. Escherichia coli O157:H7, Listeria monocytogenes, Salmonella enterica ser. Typhimurium, Staphylococcus aureus, Pseudomonas fragi, and Penicillium chrysogenum were used as indicators.