Behavior and Enterotoxin Production by Coagulase Negative Staphylococcus in Cooked Ham, Reconstituted Skimmed Milk, and Confectionery Cream

作者：Oliveira Ana Maria; Nago Miya Norma Teruko; Sant'Ana Anderson S; Pereira Jose Luiz^*

来源：Journal of Food Science, 2010, 75(7): M475-M481.

DOI：10.1111/j.1750-3841.2010.01754.x

• coagulase-negative staphylococci
• confectionery cream
• enterotoxigenic staphylococci
• enterotoxin
• food safety
• ham
• skimmed milk powder

In this study, the behavior and enterotoxin production by 10 different coagulase negative Staphylococcus (CNS) strains inoculated in cooked ham, reconstituted skimmed milk, and confectionery cream in the presence or absence of background microbiota have been investigated. After inoculation (103 CFU/g), foods were incubated at 25, 30, and 37 degrees C and aerobic mesophilic and CNS counts were carried out at 12, 24, 48, and 72 h. Staphylococcal enterotoxins (SE) detection was performed by SET-RPLA (Oxoid, Basingstoke, U.K.) and mini-Vidas (R) (bioMerieux, La Balme les Grottes, France). CNS counts increased during incubation and approached 106 to 107 CFU/g after 12 h at 37 degrees C in the 3 foods studied. At 25 degrees C, counts reached 106 to 107 CFU/g only after 24 to 48 h. The interference of background microbiota on CNS behavior was only observed when they grew in sliced cooked ham, which presented a high initial total count (105 CFU/g). Significantly higher counts of CNS isolated from raw cow's milk in comparison with food handlers isolates were found in reconstituted milk and confectionery cream. Although CNS strains were able to produce SEA, SEB, and SED in culture media, in foods, in the presence or absence of background microbiota S. chromogenes LE0598 was the only strain able to produce SEs. Despite the scarcity of reports on CNS involvement with foodborne disease outbreaks, the results found here support the CNS growth and SE production in foods even in the presence of background microbiota and may affect food safety.

• 出版日期2010-9-10