Antibacterial Effect of Caprylic Acid and Monocaprylin on Major Bacterial Mastitis Pathogens

Abstract

Bovine mastitis is the most significant economic drain on the worldwide dairy industry. Concerns regarding poor cure rates, emergence of bacterial resistance, and residues in milk necessitate development of alternative therapeutic approaches to antibiotics for treatment of mastitis. A variety of free fatty acids and their monoglycerides have been reported to exert antimicrobial activity against a wide range of microorganisms. The objective of our study was to examine the efficacy of caprylic acid, a short-chain fatty acid, and its monoglyceride, monocaprylin, to inactivate common mastitis pathogens, including Streptococcus agalactiae, Streptococcus dysgalactiae, Streptococcus uberis, Staphylococcus aureus, and Escherichia coli. Milk samples containing 50 mM or 100 mM caprylic acid, and 25 mM or 50 mM monocaprylin were inoculated separately with a 3-isolate mixture of each of the 5 pathogens, and incubated at 39 degrees C. Populations of surviving bacteria were determined at 0 min, 1 min, 6 h, 12 h, and 24 h of incubation. Both caprylic acid and monocaprylin reduced all 5 pathogens by >5.0 log cfu/mL after 6 h of incubation. Among the bacterial species tested, Strep. agalactiae, Strep. dysgalactiae, and Strep. uberis were most sensitive, and E. coli was most tolerant to caprylic acid and monocaprylin. Results of this study indicate that caprylic acid and monocaprylin should be evaluated as alternatives or adjuncts to antibiotics as intra-mammary infusion to treat bovine mastitis.

Effects of Sodium Octanoate, Acylated Ghrelin, and Desacylated Ghrelin on the Growth of Genetically Engineered Escherichia Coli

“…octanoate) present in ghrelin might be utilized by a similar pathway in the E. coli MK79 and MK57 strains. The data presented here do not support this assumption because the growth of both strains was dramatically inhibited by the presence of either free sodium octanoate (9)(10)(11) or acylated ghrelin, the peptide characterized by the presence of an n-octanoylation on the hydroxy group of the serine in position 3. Thus, our results lend credence to those of Chorny et al (20).…”

Bacillus anthracis produces membrane-derived vesicles containing biologically active toxins

“…We recovered disproportionately few vesicles relative to the number of cells in suspension, which we attribute to inherent instability of vesicles and disruption during the isolation process. Lipid analysis of isolated vesicles revealed the presence of various fatty acids, which have been identified in other Gram-positive bacteria, such as S. aureus (41)(42)(43). The metabolic labeling experiment revealed a rapid rise in radiation-associated sedimentable material that was followed by a decrease and then a steady state phase.…”

Comparison of antibacterial effect of seven 1-monoglycerides on food-borne pathogens or spoilage bacteria

“…Another hypothesis is based on the penetration of fatty acids with a short and medium chain in a non-dissociated form into bacterial cells and their dissociation inside the cells, which leads to acidification of the cell contents (Sado Kamdem et al 2008). Reduction in the intracellular pH can lead to inactivation of the intracellular enzymes (Nair et al 2005). The inhibitory effect of monoglycerides can be increased by organic acids (Tokarskyy and Marshall 2008) or chelation agents (Branen and Davidson 2004).…”