Growth and survival of Escherichia coli O157:H7 under acidic conditions.
AUTOR(ES)
Conner, D E
RESUMO
The effect of pH reduction with acetic (pH 5.2), citric (pH 4.0), lactic (pH 4.7), malic (pH 4.0), mandelic (pH 5.0), or tartaric (pH 4.1) acid on growth and survival of Escherichia coli O157:H7 in tryptic soy broth with 0.6% yeast extract held at 25, 10, or 4 degrees C for 56 days was determined. Triplicate flasks were prepared for each acid treatment at each temperature. At 25 degrees C, populations increased 2 to 4 log10 CFU/ml in all treatments except that with mandelic acid, whereas no growth occurred at 10 or 4 degrees C in any treatments except the control. However, at all sampling times, higher (P < 0.05) populations were recovered from treatments held at 4 degrees C than from those held at 10 degrees C. At 10 degrees C, E. coli O157:H7 was inactivated at higher rates in citric, malic, and mandelic acid treatments than in the other treatments. At the pH values tested, the presence of the organic acids enhanced survival of the pathogen at 4 degrees C compared with the unacidified control. E. coli O157:H7 has the ability to survive in acidic conditions (pH, > or = 4.0) for up to 56 days, but survival is affected by type of acidulant and temperature.
ACESSO AO ARTIGO
http://www.pubmedcentral.nih.gov/articlerender.fcgi?artid=167295Documentos Relacionados
- Acid adaptation of Escherichia coli O157:H7 increases survival in acidic foods.
- Survival and growth of Escherichia coli O157:H7 on salad vegetables.
- Survival in acidic and alcoholic medium of Shiga toxin-producing Escherichia coli O157:H7 and non-O157:H7 isolated in Argentina
- Loss of O157 O Antigenicity of Verotoxin-Producing Escherichia coli O157:H7 Surviving under Starvation Conditions
- Loss of O157 O Antigenicity of Verotoxin-Producing Escherichia coli O157:H7 Surviving under Starvation Conditions