TY - JOUR
T1 - Behavior of Streptococcus pyogenes in mashed potatoes
AU - Trujillo, Fausto Tejeda
AU - Escartín, Eduardo Fernández
AU - Cerezo, Silvia Giono
PY - 2004/7
Y1 - 2004/7
N2 - Streptococcus pyogenes is widely recognized as a human pathogen. Whereas person-to-person transmission is the most common transmission mechanism for this pathogen, some outbreaks of S. pyogenes disease have been reported to occur in association with consumption of contaminated foods such as shrimp or potato salads. In this study, the behavior of S. pyogenes was studied in mashed potatoes as a function of storage temperature, types and amount of background biota and type of ingredients. Combined mashed potatoes (potatoes, butter, milk, egg and table salt) or plain mashed potatoes (potatoes only) were inoculated with a 5-strain cocktail of S. pyogenes and stored at 7, 25, 35 or 37C. At intervals during storage, samples were collected for counting S. pyogenes in blood agar plates or blood agar added with sodium azide, polymyxin and crystal violet. Mashed potatoes obtained from fast-food restaurants were used to determine the fate of S. pyogenes as affected by changes in aerobic mesophiles, coliform and lactic acid bacteria counts. S. pyogenes was able to survive in mashed potatoes stored at 7C and to grow in mashed potatoes stored at 25 or 37C with lag phase lengths of 3 and 2 h and generation times of 26.0 and 25.3 min, respectively. The generation time of S. pyogenes in plain mashed potatoes was 30.7 min at 35C. Presence of active background biota at 2-3 log10 CFU/g concentrations did not prevent growth of S. pyogenes when stored at 35C. These results contribute to a better understanding of the potential for S. pyogenes to cause foodborne outbreaks.
AB - Streptococcus pyogenes is widely recognized as a human pathogen. Whereas person-to-person transmission is the most common transmission mechanism for this pathogen, some outbreaks of S. pyogenes disease have been reported to occur in association with consumption of contaminated foods such as shrimp or potato salads. In this study, the behavior of S. pyogenes was studied in mashed potatoes as a function of storage temperature, types and amount of background biota and type of ingredients. Combined mashed potatoes (potatoes, butter, milk, egg and table salt) or plain mashed potatoes (potatoes only) were inoculated with a 5-strain cocktail of S. pyogenes and stored at 7, 25, 35 or 37C. At intervals during storage, samples were collected for counting S. pyogenes in blood agar plates or blood agar added with sodium azide, polymyxin and crystal violet. Mashed potatoes obtained from fast-food restaurants were used to determine the fate of S. pyogenes as affected by changes in aerobic mesophiles, coliform and lactic acid bacteria counts. S. pyogenes was able to survive in mashed potatoes stored at 7C and to grow in mashed potatoes stored at 25 or 37C with lag phase lengths of 3 and 2 h and generation times of 26.0 and 25.3 min, respectively. The generation time of S. pyogenes in plain mashed potatoes was 30.7 min at 35C. Presence of active background biota at 2-3 log10 CFU/g concentrations did not prevent growth of S. pyogenes when stored at 35C. These results contribute to a better understanding of the potential for S. pyogenes to cause foodborne outbreaks.
UR - http://www.scopus.com/inward/record.url?scp=4043134575&partnerID=8YFLogxK
U2 - 10.1111/j.1745-4565.2004.tb00381.x
DO - 10.1111/j.1745-4565.2004.tb00381.x
M3 - Artículo
SN - 0149-6085
VL - 24
SP - 147
EP - 158
JO - Journal of Food Safety
JF - Journal of Food Safety
IS - 2
ER -