Inhibition of Salmonella Enteritidis by cerein 8A, EDTA and sodium lactate.
The ability of the bacteriocin cerein 8A to inhibit Salmonella Enteritidis in combination with EDTA and sodium lactate was investigated. Salmonella Enteritidis was incubated with combinations of cerein 8A (3200AU/mL) and EDTA (20, 50, 100 mmol/L) or sodium lactate (200 mmol/L). All treatments caused a significant reduction in the OD(600) values of Salmonella Enteritidis cultures. The addition of cerein 8A plus EDTA resulted in higher inhibition in comparison with the bacteriocin alone; the greater the concentration of EDTA, the greater the inhibitory effect. The combination of cerein 8A plus 100 mmol/L EDTA results in a more efficient treatment to reduce the number of viable cells of Salmonella Enteritidis. The combination of cerein 8A plus sodium lactate also showed significant inhibition of the indicator organism. Transmission electron microscopy showed damaged cell walls and loss of protoplasmic material in treated cells. The cells of Salmonella Enteritidis treated with cerein 8A plus EDTA appeared more injured. The bacteriocin cerein 8A may be useful to inhibit Gram-negative bacteria, with enhanced effect in combination with chelating agents. Control of Salmonella Enteritidis, a Gram-negative bacterium constantly linked to food outbreaks, addresses an important aspect of food safety.
Laboratório de Bioquímica e Microbiologia Aplicada, Departamento de Ciência de Alimentos, ICTA, Universidade Federal do Rio Grande do Sul, 91501-970 Porto Alegre, Brazil.
Rosiele
R
Lappe
Amanda S
AS
Motta
Voltaire
V
Sant'anna
Adriano
A
Brandelli
D000890:Anti-Infective Agents / Q000494:pharmacology*; D001430:Bacteriocins / Q000494:pharmacology*; D002473:Cell Wall / Q000187:drug effects; D002614:Chelating Agents / Q000494:pharmacology*; D015169:Colony Count, Microbial; D003593:Cytoplasm / Q000187:drug effects; D004305:Dose-Response Relationship, Drug; D004359:Drug Therapy, Combination; D004492:Edetic Acid / Q000494:pharmacology*; D050296:Microbial Viability / Q000187:drug effects*; D046529:Microscopy, Electron, Transmission; D012477:Salmonella enteritidis / Q000187:drug effects* / Q000254:growth & development; D019354:Sodium Lactate / Q000494:pharmacology*
D000890:Anti-Infective Agents; D001430:Bacteriocins; D002614:Chelating Agents; C505873:cerein 8A, Bacillus cereus; D004492:Edetic Acid; D019354:Sodium Lactate