Research Publications (Food Safety)

Publication date: 4 May 2015
, Volume 200
Author(s): Noor-Azira Abdul-Mutalib , Syafinaz Amin Nordin , Malina Osman , Natsumi Ishida , Kosuke Tashiro , Kenji Sakai , Yukihiro Tashiro , Toshinari Maeda , Yoshihito Shirai

Flagella are multiprotein complexes necessary for swimming and swarming motility. In Salmonella enterica serovar Typhimurium, flagella-mediated motility is repressed by the PhoP/PhoQ regulatory system. We now report that Salmonella can move on 0.3% agarose media in a flagella-independent manner when experiencing the PhoP/PhoQ-inducing signal low Mg2+. This motility requires the...

The objective of this study was to establish quantitative evaluation models for fish microbiological quality analysis based on electronic tongue technique coupled with nonlinear pattern recognition algorithms. Crucian carp stored at 4C were used. A commercial electronic tongue system was employed. The total viable counts (TVCs) of fish samples were measured by the classical microbiological plating method.

This study was conducted to confirm the synergistic inactivation effect of flower pollen when applied with heat treatment to Escherichia coli O157:H7. The reduction of the number of E. coli O157:H7 was monitored during heat treatment at 55, 57.5, 60, 62.5 and 65C.

Publication date: July 2015
, Volume 53
Author(s): Maurício S. Oliveira , Andressa C.L. Diel , Ricardo H. Rauber , Fabiana P. Fontoura , Adriano Mallmann , Paulo Dilkin , Carlos A. Mallmann

Publication date: August 2015
, Volume 54
Author(s): Aline M. Bortoletto , André R. Alcarde

Effects of plant polyphenolstea polyphenol [TP], grape seed extract [GSE], and gingerol) and α-tocopherol on physicochemical parameters, microbiological counts, and biogenic amines were determined in dry-cured bacons at the end of ripening. Results showed that plant polyphenols and α-tocopherol significantly decreased pH, thiobarbituric acid reactive substances content, and total volatile basic nitrogen (TVBN) compared with the control (P < 0.05).

Publication date: 4 May 2015
, Volume 200
Author(s): Xiangning Bai , Hong Wang , Youquan Xin , Rongjie Wei , Xinyuan Tang , Ailan Zhao , Hui Sun , Wang Zhang , Yan Wang , Yanmei Xu , Zhengdong Zhang , Qun Li , Jianguo Xu , Yanwen Xiong

Escherichia albertii is a recently described species that has been associated with gastroenteritis in humans and with healthy and ill birds. Most recently, it has been identified as the causative agent in a food-borne outbreak in Japan. The distribution and clinical importance of E. albertii are not well studied because its importance is unclear. Culture methods for clinical isolation frequently miss E. albertii or incorrectly identify it as Shigella spp., Escherichia coli, or Hafnia alvei.

Moribund shrimp affected by acute hepatopancreatic necrosis disease (AHPND) from farms in northwestern Mexico were sampled for bacteriological and histological analysis. Bacterial isolates were molecularly identified as Vibrio parahaemolyticus by the presence of the tlh gene. The tdh-negative, trh-negative, and tlh-positive V.

Escherichia coli isolates (n = 658) obtained from drinking water intakes of Comox Lake (2011 to 2013) were screened for the following virulence genes (VGs): stx1 and stx2 (Shiga toxin-producing E. coli [STEC]), eae and the adherence factor (EAF) gene (enteropathogenic E. coli [EPEC]), heat-stable (ST) enterotoxin (variants STh and STp) and heat-labile enterotoxin (LT) genes (enterotoxigenic E. coli [ETEC]), and ipaH (enteroinvasive E. coli [EIEC]).

Two hybrid bacteriocins, enterocin E50-52/pediocin PA-1 (EP) and pediocin PA-1/enterocin E50-52 (PE), were designed by combining the N terminus of enterocin E50-52 and the C terminus of pediocin PA-1 and by combining the C terminus of pediocin PA-1 and the N terminus of enterocin E50-52, respectively. Both hybrid bacteriocins showed reduced MICs compared to those of their natural counterparts.

Lantibiotics are ribosomally synthesized peptides that contain multiple posttranslational modifications. Research on lantibiotics has increased recently, mainly due to their broad-spectrum antimicrobial activity, especially against some clinical Gram-positive pathogens. Many reports about various bacteriocins in the Bacillus cereus group have been published, but few were about lantibiotics.

Listeria monocytogenes is involved in food-borne illness with a high mortality rate. The persistence of the pathogen along the food chain can be associated with its ability to form biofilms on inert surfaces. While most of the phenotypes associated with biofilms are related to their spatial organization, most published data comparing biofilm formation by L. monocytogenes isolates are based on the quantitative crystal violet assay, which does not give access to structural information.

Enterohemorrhagic Escherichia coli (EHEC) strains, of which E. coli O157:H7 is the best-studied serotype, are an important group of foodborne pathogens causing severe illness in humans worldwide. The main reservoirs for EHEC are ruminants, mostly cattle, which harbor the bacteria in their intestinal tracts without showing clinical symptoms.

The Gram-negative enteric bacterium Citrobacter rodentium is a natural mouse pathogen that has been extensively used as a surrogate model for studying the human pathogens enteropathogenic and enterohemorrhagic Escherichia coli. All three pathogens produce similar attaching and effacing (A/E) lesions in the intestinal epithelium. During infection these bacteria employ surface structures called fimbriae to adhere and colonize the host intestinal epithelium. For C.

Publication date: July 2015
, Volume 53
Author(s): Clara Miracle Belda-Galbis , Antonio Jiménez-Carretón , María Consuelo Pina-Pérez , Antonio Martínez , Dolores Rodrigo

Rebecca Cote, Robab Katani, Matthew R. Moreau, Indira T. Kudva, Terrance M. Arthur, Chitrita DebRoy, Michael M. Mwangi, Istvan Albert, Juan Antonio Raygoza Garay, Lingling Li, Maria T. Brandl, Michelle Q. Carter, Vivek Kapur

Elevated levels of the second messenger c-di-GMP activate biosynthesis of an unknown exopolysaccharide (EPS) in the food-borne pathogen Listeria monocytogenes. This EPS strongly protects cells against disinfectants and desiccation, indicating its potential significance for listerial persistence in the environment and for food safety.

Rauna Riva, Timo K. Korhonen and Seppo Meri The virulence factor PgtE is an outer membrane protease (omptin) of the zoonotic pathogen Salmonella enterica that causes diseases ranging from gastroenteritis to severe enteric fever. It is surface exposed in bacteria that have a short-chain, i.e., rough LPS, as observed e.g., in bacteria residing inside macrophages or just emerging from them.

Publication date: July 2015
, Volume 53
Author(s): Mahmoud Ahmed Mohammed , Khalid Ibrahim Sallam , Tomohiro Tamura

Wei Xia, Pengjun Shi, Xinxin Xu, Lichun Qian, Ying Cui, Mengjuan Xia, Bin Yao

Publication date: July 2015
, Volume 53
Author(s): Jia Xin Chong , Shaojuan Lai , Hongshun Yang

Publication date: July 2015
, Volume 53
Author(s): Ibrahim Mehmeti , Skender Muji , Dzung B. Diep , Ingolf F. Nes

Publication date: July 2015
, Volume 53
Author(s): Philip G. Crandall , Corliss A. O'Bryan , Robin Peterson , Natalie Dyenson , Frank Yiannas