Effect of Selected Lactic Acid Bacteria on Growth of Staphylococcus aureus and Production of Enterotoxin1

Abstract

Representative strains of 15 species of lactic acid bacteria were examined for their ability to influence growth of Staphylococcus aureus and production of enterotoxin in associative culture. Among the organisms used as effectors the streptococci were-most inhibitory, followed by Pediococcus cerevisiae. The lactobacilli and Leuconostoc citrovorum were not inhibitory to growth and only slightly inhibitory to production of enterotoxin. Enterotoxin was detected in all cultures in which the population of S. aureus reached 8 x 107 per ml. At lower S. aureus populations no enterotoxin was detected after incubation for 48 h. Mechanisms of inhibition of growth and enterotoxin production by S. aureus strain 243 grown in association with Streptococcus lactis A64 or P. cerevisiae 10791 in APT broth were investigated. Competition for vital nutrients, especially niacin and biotin, and probably production of hydrogen peroxide contribute to inhibition. Production of lactic acid appears to inhibit growth of S. aureus in the early but not the late stages of incubation. MATERIALS AND METHODS Cultures. S. aureus 243 produces enterotoxin B and was obtained from the late E. P. Casman of the Federal Food and Drug Administration, Washington, D.C. S. lactis A62, A64, A254, G18; S. cremoris E8; Pediococcus cerevisiae FBB39 and FBB63; Lactobacillus plantarum FBB12; and Lactobacillus casei 54 were stock cultures from the Food Microbiology Laboratory at Michigan State University. Streptococcus thermophilus W, Leuconostoc citrovorum

Microbial Interactions in Country‐style Hams

“…The Bacillus isolate was auto-stimulatory and the Enterobacteriaceae were stimulatory to some of the other Enterobacteriaceae isolates. Although only slight inhibition by P. cerevisiae was observed in the agar overlay study, statistical analyses indicated this lactic acid producer to be inhibitory to most of the microorganisms in dry-cured ham tissue including staphylococci, micrococci, lactobacilli, Enterobacteriaceae and yeasts (Table 7), indicated by negative correlation coefficients (P < 0.05) which agrees with results found by other workers except for yeast inhibition (Daly et al, 1973;Al-Mashat, 1973;Haines and Harmon, 1973). Fleming et al (1975) reported only two isolates of pediococci from cucumber brine were inhibitory to other Gram positive organisms while 13 other isolates of Table B-Microbial interactions by agara overlay method pediococci from cucumber brine and various other sources were not.…”

Staphylococcus aureusand its food poisoning toxins: characterization and outbreak investigation

“…Staphylococcus aureus does not grow well in the presence of a competitive flora. Its inhibition is mainly because of acidic products, lowering of the pH, production of H 2 O 2 or other inhibitory substances like antibiotics, volatile compounds or nutritional competition (Haines & Harmon, 1973;Genigeorgis, 1989). Important factors affecting the degree of inhibition are the ratio of the numbers of competitors to the number of S. aureus as well as the temperature (Smith et al, 1983;Genigeorgis, 1989).…”

Staphylococcus aureus virulence and metabolism are dramatically affected by Lactococcus lactis in cheese matrix

“…However, again, most of our knowledge relies on observations or screenings for inhibitory activities, the molecular mechanisms of which remain unknown. Lactic acid bacteria antagonism is a complex and multifactorial phenomenon, which includes production of inhibitory compounds (bacteriocin, hydrogen peroxide), acidification and nutritional competition (Barber and Deibel, 1972; Haines and Harmon, 1973; Notermans and Heuvelman, 1983; Ammor et al ., 2006; Delbes et al ., 2006; Otero and Nader‐Macias, 2006; Charlier et al ., 2009). Molecular and global approaches, including transcriptomics and proteomics, are powerful tools that have already allowed deciphering some of the mechanisms underlying the action of one bacterial species upon another (Mashburn et al ., 2005; Laughton et al ., 2006).…”