Growth behavior comparison of Listeria monocytogenes between Type strains and beef isolates in raw beef

Food Science and Biotechnology - This study was conducted to compare the growth parameters of Listeria monocytogenes between beef isolates and Type strains in raw beef. Beef was artificially...     

Antibacterial activities of polyphenols against foodborne pathogens and their application as antibacterial agents

Food Science and Biotechnology - Polyphenols are secondary metabolites produced in higher plants. They are known to possess various functional properties in the human body. Polyphenols also exhibit...     

Performance comparison of 5 selective media used to detect Staphylococcus aureus in foods

Performance comparison tests were carried out on Staphylococcus aureus selective media recommended by food safety agencies or approved by international standardization bodies. The performance of mannitol salt agar (MSA), Baird parker agar, Vogel johnson agar, RAPID’ Staph, and CHROMagar staph aureus are compared. Four out of the 5 media showed 100% sensitivity, with MSA showing 96.5%. MSA also showed only 66.6% specificity, while 4 out of 5 media showed 100% specificity. In recovery tests S. aureus was more easily recovered from instant cooked rice than fish fillet. The tested media did not have a significant difference on recovery activity.     

Efficacy of aerosolized peroxyacetic acid as a sanitizer of lettuce leaves

Aerosolized sanitizer was investigated as a potential alternative to aqueous and gaseous sanitizers for produce. Peroxyacetic acid was aerosolized (5.42 to 11.42 microm particle diameter) by a commercially available nebulizer into a model cabinet. Iceberg lettuce leaves were inoculated with three strains each of Escherichia coli O157:H7, Listeria monocytogenes, and Salmonella Typhimurium and then treated with aerosolized peroxyacetic acid for 10, 30, or 60 min in a model aerosol cabinet at room temperature (22 +/- 2 degrees C). After treatment, surviving healthy and injured bacterial cells were enumerated on appropriate selective agars or using the overlay agar method. Inoculated iceberg lettuce leaves exposed to aerosolized peroxyacetic acid for 10 min exhibited a 0.8-log reduction in E. coli O157:H7, a 0.3-log reduction in Salmonella Typhimurium, and a 2.5-log reduction in L. monocytogenes when compared with the control. After 30 min of treatment, the three pathogens were reduced by 2.2, 3.3, and 2.7 log, and after 60 min, the reductions were 3.4, 4.5, and 3.8 log, respectively. Aerosolization may be a new and convenient method for sanitizing produce for storage or shipping.     

Distribution of newly described enterotoxin-like genes in <Emphasis Type="Italic">Staphylococcus aureus</Emphasis> isolated from ready-to-eat foods in Korea

To investigate the distribution of staphylococcal enterotoxin-like (SEl) genes in Staphylococcus aureus from food, a total of 154 S. aureus isolates from ready-to-eat (RTE) foods in Korea were analyzed by mutiplex PCR for the detection of the following 9 staphylococcal enterotoxin-like genes; sek, sel, sem, sen, seo, sep, seq, ser, and seu. Seventy-nine isolates (51.3%) were found to have at least one of SEl genes. The major SEl genes were sek, sem, sen, and seq. Other SEl genes found in the isolates were seo (21 isolates, 13.6%), seu (12 isolates, 7.8%), sep (8 isolates, 5.2%), sel (7 isolates, 4.5%), and ser (2 isolates, 1.3%). Most (95%) of the isolates with staphylococcal enterotoxin (SE) genes were also carried SEl genes. The genes seg, sei, sem, and sen were all detected in the same isolates. Ninety-seven % of isolates with seg+sei+sem+sen also contained seo or seu. Ninety-four % of isolates with sea+seh were found to coexist with sek+seq. The toxic shock syndrome toxin gene, tst-1, was found in all isolates with egc-2, including seg, sei, sem, sen, and seu. The coexistence of SE and SEl genes in S. aureus isolates from RTE foods can be explained by the mobile genetic elements. Because of the mobile genetic element, SE and SEl genes of S. aureus in foods may be transferable to nontoxigenic S. aureus and other food pathogens. Additional studies must be conducted to prevent spread of pathogenic genes such as enterotoxin gene.     

Effects of malic acid or/and grapefruit seed extract for the inactivation of common food pathogens on fresh-cut lettuce

Food Science and Biotechnology - This study investigated the antimicrobial activity of malic acid (MA), grapefruit seed extract (GSE), and combined (MA+GSE) treatment against Escherichia coli...     

Inactivation of Salmonella Typhimurium and Escherichia coli O157:H7 on black pepper powder using UV-C,UV-A and TiO2 coating

Food Science and Biotechnology - This study was conducted to measure the inactivation characteristics of UVs and TiO2 against Salmonella. Typhimurium and Escherichia coli O157:H7 on black pepper...     

Enhancing the antimicrobial activity of ginseng against Bacillus cereus and Staphylococcus aureus by heat treatment

Food Science and Biotechnology - This study evaluated the antimicrobial activities [diffusion inhibition zone, minimum inhibitory concentration (MIC), and minimum bactericidal concentration], of...     

The antimicrobial effect of thiamine dilauryl sulfate in tofu inoculated with Escherichia coli O157:H7, Salmonella Typhimurium,Listeria monocytogenes and Bacillus cereus

Food Science and Biotechnology - Thiamine dilauryl sulfate (TDS) is a food additive that is used as a bactericidal agent. This study examines the antimicrobial effect of TDS on tofu inoculated with...     

Optimization of resuscitation-promoting broths for the revival of Vibrio parahaemolyticus from a viable but nonculturable state

Food Science and Biotechnology - This study was conducted to examine the effect of formulated resuscitation-promoting broths on the revival of viable but nonculturable Vibrio parahaemolyticus...