Shilling Michael, Matt Laurie, Rubin Evelyn, Visitacion Mark Paul, Haller Nairmeen A, Grey Scott F, Woolverton Christopher J
1 School of Biomedical Sciences, Kent State University , Kent, Ohio, USA .
J Med Food. 2013 Dec;16(12):1079-85. doi: 10.1089/jmf.2012.0303.
Clostridium difficile is the leading cause of hospital-acquired antibiotic-associated diarrhea worldwide; in addition, the proliferation of antibiotic-resistant C. difficile is becoming a significant problem. Virgin coconut oil (VCO) has been shown previously to have the antimicrobial activity. This study evaluates the lipid components of VCO for the control of C. difficile. VCO and its most active individual fatty acids were tested to evaluate their antimicrobial effect on C. difficile in vitro. The data indicate that exposure to lauric acid (C12) was the most inhibitory to growth (P<.001), as determined by a reduction in colony-forming units per milliliter. Capric acid (C10) and caprylic acid (C8) were inhibitory to growth, but to a lesser degree. VCO did not inhibit the growth of C. difficile; however, growth was inhibited when bacterial cells were exposed to 0.15-1.2% lipolyzed coconut oil. Transmission electron microscopy (TEM) showed the disruption of both the cell membrane and the cytoplasm of cells exposed to 2 mg/mL of lauric acid. Changes in bacterial cell membrane integrity were additionally confirmed for VCO and select fatty acids using Live/Dead staining. This study demonstrates the growth inhibition of C. difficile mediated by medium-chain fatty acids derived from VCO.
艰难梭菌是全球医院获得性抗生素相关性腹泻的主要病因；此外，耐抗生素的艰难梭菌的增殖正成为一个重大问题。初榨椰子油（VCO）此前已被证明具有抗菌活性。本研究评估了VCO的脂质成分对艰难梭菌的控制作用。对VCO及其最具活性的单一脂肪酸进行测试，以评估它们在体外对艰难梭菌的抗菌效果。数据表明，通过每毫升菌落形成单位的减少来确定，暴露于月桂酸（C12）对生长的抑制作用最强（P<0.001）。癸酸（C10）和辛酸（C8）对生长有抑制作用，但程度较小。VCO并未抑制艰难梭菌的生长；然而，当细菌细胞暴露于0.15 - 1.2%的水解椰子油时，生长受到抑制。透射电子显微镜（TEM）显示，暴露于2 mg/mL月桂酸的细胞的细胞膜和细胞质均遭到破坏。使用活/死染色法进一步证实了VCO和特定脂肪酸对细菌细胞膜完整性的影响。本研究证明了由VCO衍生的中链脂肪酸介导的艰难梭菌生长抑制作用。
