AIMS: The aim of this study was to associate the growth limits of Listeria monocytogenes during exposure to combined stresses with specific serotypes or origins of isolation, and identify potential genetic markers. METHODS AND RESULTS: The growth of 138 strains was assessed at different temperatures using combinations of low pH, sodium lactate, and high salt concentrations in brain heart infusion broth. None of the strains was able to grow at pH < or = 4.4, a(w) < or = 0.92, or pH < or = 5.0 combined with a(w) < or = 0.94. In addition, none of the strains grew at pH < or = 5.2 and NaLac > or = 2%. At 30 degrees C, the serotype 4b strains showed the highest tolerance to low pH and high NaCl concentrations at both pH neutral (pH 7.4) and mild acidic conditions (pH 5.5). At 7 degrees C, the serotype 1/2b strains showed the highest tolerance to high NaCl concentrations at both pH 7.4 and 5.5. Serotype 1/2b meat isolates showed the highest tolerance to low pH in the presence of 2% sodium lactate at 7 degrees C. ORF2110 and gadD1T1 were identified as potential biomarkers for phenotypic differences. CONCLUSIONS: Differences in growth limits were identified between specific L. monocytogenes strains and serotypes, which could in some cases be associated with specific genetic markers. SIGNIFICANCE AND IMPACT OF THE STUDY: Our data confirm the growth limits of L. monocytogenes as set out by the European Union for ready-to-eat foods and provides an additional criterion. The association of L. monocytogenes serotypes with certain stress responses might explain the abundance of certain serotypes in retail foods while others are common in clinical cases.
AIMS: The aim of this study was to associate the growth limits of Listeria monocytogenes during exposure to combined stresses with specific serotypes or origins of isolation, and identify potential genetic markers. METHODS AND RESULTS: The growth of 138 strains was assessed at different temperatures using combinations of low pH, sodium lactate, and high salt concentrations in brain heart infusion broth. None of the strains was able to grow at pH < or = 4.4, a(w) < or = 0.92, or pH < or = 5.0 combined with a(w) < or = 0.94. In addition, none of the strains grew at pH < or = 5.2 and NaLac > or = 2%. At 30 degrees C, the serotype 4b strains showed the highest tolerance to low pH and high NaCl concentrations at both pH neutral (pH 7.4) and mild acidic conditions (pH 5.5). At 7 degrees C, the serotype 1/2b strains showed the highest tolerance to high NaCl concentrations at both pH 7.4 and 5.5. Serotype 1/2b meat isolates showed the highest tolerance to low pH in the presence of 2% sodium lactate at 7 degrees C. ORF2110 and gadD1T1 were identified as potential biomarkers for phenotypic differences. CONCLUSIONS: Differences in growth limits were identified between specific L. monocytogenes strains and serotypes, which could in some cases be associated with specific genetic markers. SIGNIFICANCE AND IMPACT OF THE STUDY: Our data confirm the growth limits of L. monocytogenes as set out by the European Union for ready-to-eat foods and provides an additional criterion. The association of L. monocytogenes serotypes with certain stress responses might explain the abundance of certain serotypes in retail foods while others are common in clinical cases.
Authors: Alejandra A Latorre; Jo Ann S Van Kessel; Jeffrey S Karns; Michael J Zurakowski; Abani K Pradhan; Kathryn J Boor; Evin Adolph; Sharinne Sukhnanand; Ynte H Schukken Journal: Appl Environ Microbiol Date: 2011-03-25 Impact factor: 4.792
Authors: Teresa M Bergholz; Henk C den Bakker; Esther D Fortes; Kathryn J Boor; Martin Wiedmann Journal: Foodborne Pathog Dis Date: 2010-08-14 Impact factor: 3.171
Authors: Danilo Augusto Lopes da Silva; Rafaela de Melo Tavares; Anderson Carlos Camargo; Ricardo Seiti Yamatogi; Elaine Cristina Pereira De Martinis; Luís Augusto Nero Journal: World J Microbiol Biotechnol Date: 2021-06-16 Impact factor: 3.312
Authors: Patricia Hingston; Jessica Chen; Bhavjinder K Dhillon; Chad Laing; Claire Bertelli; Victor Gannon; Taurai Tasara; Kevin Allen; Fiona S L Brinkman; Lisbeth Truelstrup Hansen; Siyun Wang Journal: Front Microbiol Date: 2017-03-08 Impact factor: 5.640