title: Assessment of Enterotoxin Production and Cross-Contamination of Staphylococcus aureus between Food Processing Materials and Ready-To-Eat Cooked Fish Paste.
abstract: This study evaluated Staphylococcus aureus growth and subsequent staphylococcal enterotoxin A production in tryptone soy broth and on ready-to-eat cooked fish paste at 12 to 37 °C, as well as cross-contamination between stainless steel, polyethylene, and latex glove at room temperature. A model was developed using Barany and Roberts's growth model, which satisfactorily described the suitable growth of S. aureus with R(2)-adj from 0.94 to 0.99. Except at 12 °C, S. aureus cells in TSB presented a lag time lower (14.64 to 1.65 h), grew faster (0.08 to 0.31 log CFU/h) and produced SEA at lower cell density levels (5.65 to 6.44 log CFU/mL) compare to those inoculated on cooked fish paste with data of 16.920 to 1.985 h, 0.02 to 0.23 log CFU/h, and 6.19 to 7.11 log CFU/g, respectively. Staphylococcal enterotoxin type A (SEA) visual immunoassay test showed that primary SEA detection varied considerably among different storage temperature degrees and media. For example, it occurred only during exponential phase at 30 and 37 °C in TSB, but in cooked fish paste it took place at late exponential phase of S. aureus growth at 20 and 25 °C. The SEA detection test was negative on presence of S. aureus on cooked fish paste stored at 12 and 15 °C, although cell density reached level of 6.12 log CFU/g at 15 °C. Cross-contamination expressed as transfer rate of S. aureus from polyethylene surface to cooked fish paste surface was slower than that observed with steel surface to cooked fish paste under same conditions. These results provide helpful information for controlling S. aureus growth, SEA production and cross-contamination during processing of cooked fish paste.
authors.affiliation: Dept. of Food Science and Biotechnology, College of Biotechnology and Bioscience, Kangwon National Univ, Hyoja 2 dong, Chunchon, 200-701, Republic of Korea.
authors.forename: Charles Nkufi
authors.initials: CN
authors.lastname: Tango
authors.affiliation: Korea Inst. Food Safety Management Accreditation, Bomun-ro 246, Jung-gu, Daejeon, 301-722, Korea.
authors.forename: Sung-Sam
authors.initials: SS
authors.lastname: Hong
authors.affiliation: College of Food Science and Engineering, Qingdao Agricultural Univ, No. 700, Changcheng Road, Chengyang, Qingdao, 266109, China.
authors.forename: Jun
authors.initials: J
authors.lastname: Wang
authors.affiliation: Dept. of Food Science and Biotechnology, College of Biotechnology and Bioscience, Kangwon National Univ, Hyoja 2 dong, Chunchon, 200-701, Republic of Korea.
authors.forename: Deog-Hwan
authors.initials: DH
authors.lastname: Oh
mesh_terms: D000818:Animals; D015169:Colony Count, Microbial; D003296:Cooking / Q000379:methods; D003297:Cooking and Eating Utensils; D004768:Enterotoxins / Q000032:analysis*; D005396:Fish Products / Q000382:microbiology*; D005506:Food Contamination / Q000032:analysis; D005511:Food Handling / Q000379:methods*; D005516:Food Microbiology; D006801:Humans; D020959:Polyethylene; D045730:Soy Foods / Q000382:microbiology; D013193:Stainless Steel; D013202:Staphylococcal Food Poisoning / Q000209:etiology*; D013211:Staphylococcus aureus / Q000254:growth & development*
chemical_list: D004768:Enterotoxins; D013193:Stainless Steel; C026066:enterotoxin A, Staphylococcal; D020959:Polyethylene
keywords: Staphylococcus aureus; cooked fish paste; cross-contamination; enterotoxin production; growth