Mudgil Poonam
School of Medicine, University of Western Sydney, Penrith, New South Wales, Australia.
Invest Ophthalmol Vis Sci. 2014 Oct 14;55(11):7272-7. doi: 10.1167/iovs.14-15512.
Human meibomian lipids form the outermost lipid layer of the tear film and serve many important functions to maintain its integrity. Although not investigated earlier, these lipids may have antimicrobial properties that help in strengthening the innate host defense of tears at the ocular surface. The aim of this study was to investigate the antimicrobial role of human meibomian lipids.
Ocular pathogenic bacteria, Staphylococcus aureus 31, Pseudomonas aeruginosa 19, Pseudomonas aeruginosa 20, and Serratia marcescens 35, were grown in the presence and absence of human meibomian lipids in an artificial tear solution at the physiological temperature. Viable counts were obtained to note the number of bacteria surviving the treatment with meibomian lipids. Bacterial cells were imaged using scanning electron microscopy to observe the damages caused by meibomian lipids.
Viable count results showed that in the presence of meibomian lipids, growth of all bacteria was considerably lower. Scanning electron microscopy showed that meibomian lipids caused extensive cellular damage to bacteria as manifested in smaller size, loss of aggregation, abnormal phenotype, cellular distortion, damaged cell wall, and cell lysis.
This is the first-ever report of the antimicrobial role of human meibomian lipids. These lipids possess antimicrobial properties against both Gram-positive and Gram-negative bacteria and are involved in the innate host defense of tears in protecting the ocular surface against microbial pathogens.
人睑板脂质构成泪膜的最外层脂质层，并发挥许多重要功能以维持其完整性。尽管此前未作研究，但这些脂质可能具有抗菌特性，有助于加强眼表泪液的固有宿主防御。本研究的目的是调查人睑板脂质的抗菌作用。
眼部病原菌金黄色葡萄球菌31、铜绿假单胞菌19、铜绿假单胞菌20和粘质沙雷氏菌35，在生理温度下于人工泪液中，分别在有和无人睑板脂质存在的情况下培养。通过活菌计数记录经睑板脂质处理后存活的细菌数量。使用扫描电子显微镜对细菌细胞成像，以观察睑板脂质造成的损伤。
活菌计数结果显示，在有睑板脂质存在的情况下，所有细菌的生长均显著降低。扫描电子显微镜显示，睑板脂质对细菌造成广泛的细胞损伤，表现为尺寸变小、聚集丧失、表型异常、细胞变形、细胞壁受损和细胞裂解。
这是关于人睑板脂质抗菌作用的首份报告。这些脂质对革兰氏阳性菌和革兰氏阴性菌均具有抗菌特性，并参与泪液的固有宿主防御，保护眼表免受微生物病原体侵害。
