中国科技网6月1日报道（张微 编译）通过使用高精度的基因测试来区分构成人体微生物群的数以千计的细菌，纽约大学兰贡医学中心的研究人员认为他们发现了令人惊喜的一种可能——佩戴隐形眼镜者眼部感染频率增加的根本原因。

在他们提交到5月31日在新奥尔良举办的美国微生物学会年会的研究报告中，纽约大学兰贡医学中心的研究人员称他们已经确定了隐形眼镜佩戴者眼睛里一组不同的微生物，这些微生物与隐形眼镜佩戴者眼睑皮肤上的微生物组更加接近，与不佩戴隐形眼镜者眼睛里的细菌不同。

具体来说，纽约大学兰贡医学中心的研究团队发现眼球表面或结膜比眼周皮肤的细菌多样性高，而且本项研究中9个隐形眼镜佩戴者与11个不佩戴隐形眼镜者相对比，他们眼睛里的甲基杆菌，乳酸菌，不动杆菌和假单胞菌比正常量高出三倍。通过测量及绘制统计图，细菌统计多样性评分结果显示，隐形眼镜佩戴者眼部微生物组成与他们皮肤上的微生物组成相似，而与不佩戴隐形眼镜者的眼部微生物不同。

“我们的研究清晰地表明，在眼睛里放置一个外来物体，如隐形眼镜不是一个中性行为，”纽约大学微生物学家玛利亚 格洛丽亚 多明格斯-贝洛博士说。“我们希望我们未来的实验能够显示出佩戴隐形眼镜者眼睛里微生物的这些变化是否是因为手指接触眼镜引起的，还是来自于眼镜自身影响和改变眼睛里细菌被抑制或繁殖的免疫系统有关，”纽约大学兰贡医学中心副教授多明格斯-贝洛说。

“这些发现将帮助科学家们更好地了解一个长期存在的问题，为什么佩戴隐形眼镜者更容易受到眼部细菌的感染，”多明格斯-贝洛说。她的研究领域是肠道和身体其他部位的不同微生物，它们如何相互作用，现代生活方式如何影响这些微生物以及增加患病风险。她说，这些认识能够更好地提供预防感染的方法。

“自从上世纪70年代软性隐形眼镜上市以来，角膜溃疡的发病率一直在提升，”这项研究的合作者，纽约大学兰贡医学中心眼科主任、教授，杰克 铎迪克医学博士说。“常见的病原菌是假单细胞菌。这项研究表明致病的微生物来自皮肤，我们更应该关注眼睑和手部卫生来减少患病的发生，”他说。

作为这项研究的一部分，研究者采集了眼部大量的试验样本，包括眼结膜以及眼周皮肤。这些样本和使用过的隐性眼镜都在实验室做了基因分析，来确定存在细菌的种类。

佩戴隐形眼镜者眼睛里细菌的组成与眼部皮肤非常相似，佩戴隐形眼镜者的眼结膜中发现了5245种不同的细菌菌株与亚型，不佩戴隐形眼镜者眼睛里的细菌菌株是5592种。佩戴隐形眼镜者眼周皮肤上发现了类似但不同的2133种细菌菌株和亚型，而在不佩戴隐形眼镜者的眼周皮肤上发现了3849种细菌。

研究人员说，令人惊讶的是，会导致眼部感染而且在皮肤上更加突出的葡萄球菌，在不佩戴隐形眼镜者眼中被发现，研究人员对这种差异还没有合理的解释。虽然各种估计差异较大，但是许多疤痕细菌性角膜炎，或眼部炎症以及结膜感染的病例，都与佩戴隐形眼镜有关。

英文原文：

Contact lens wearers note: Your eyes may get more infections because their microbiomes changed

Using high-precision genetic tests to differentiate the thousands of bacteria that make up the human microbiome, researchers at NYU Langone Medical Center suggest that they have found a possible—and potentially surprising—root cause of the increased frequency of certain eye infections among contact lens wearers.

In a study report on their work to be presented at the annual meeting of the American Society for Microbiology on May 31 in New Orleans, NYU Langone researchers say they have identified a diverse set of microorganisms in the eyes of daily contact lenswearers that more closely resembles the group of microorganisms of their eyelid skin than the bacterial grouping typically found in the eyes of non-wearers.

Specifically, the NYU Langone team found that the eye surface, or conjunctiva, has surprisingly higher bacterial diversity than the skin directly beneath the eye and three times the usual proportion of Methylobacterium, Lactobacillus, Acinetobacter, and Pseudomonasbacteria in the eyes of the study's nine contact lens wearers than is typically found on the surface of the eyeballs of 11other men and women in the study who did not wear contact lenses. When measured and plotted on a graph, statistical germ diversity scores showed that the eye microbiome of contact lens wearers had a composition more similar to that of the wearer's skin than the eye microbiome of non-lens wearers.

"Our research clearly shows that putting a foreign object, such as a contact lens, on the eye is not a neutral act," says senior study investigator and NYU Langone microbiologist Maria Gloria Dominguez-Bello, PhD.

"What we hope our future experiments will show is whether these changes in the eye microbiome of lens wearers are due to fingers touching the eye, or from the lens's direct pressure affecting and altering the immune system in the eye and what bacteria are suppressed or are allowed to thrive," says Dominguez-Bello, an associate professor at NYU Langone.

"These findings should help scientists better understand the longstanding problem of why contact-lens wearers are more prone to eye infections than non-lens wearers," says Dominguez-Bello, whose research focuses on the different microbiomes of the gut and other body parts, how they interact, and how contemporary lifestyle practices may affect the microbiome and increase disease risk. Such understanding, she says, should point to better means of preventing infections.

"There has been an increase in the prevalence of corneal ulcers following the introduction of soft contact lenses in the 1970s," says study co-investigator Jack Dodick, MD, professor and chair of ophthalmology at NYU Langone. "A common pathogen implicated has been Pseudomonas. This study suggests that because the offending organisms seem to emanate from the skin, greater attention should be directed to eyelid and hand hygiene to decrease the incidence of this serious occurrence," he says.

As part of the study, researchers took hundreds of swabs of various parts of the eye, including the eye conjunctiva, as well as along the skin directly beneath the eye. Both swabs and used contact lenses were then subjected to genetic analysis in the lab to determine which bacteria were present.

While the bacterial composition in the eye of contact lens wearers more closely resembled that of the skin, some 5,245 distinct bacterial strains and subtypes were identified in the eye conjunctiva of lens wearers, and 5,592 strains were identified in the eyes of non-lens wearers. A similar but different composition of 2,133 strains and subtypes were identified in the skin directly beneath the eye of those with contact lenses, while 3,849 distinct bacteria were identified in non-lens wearers.

Surprisingly, researchers say, more Staphylococcus bacteria, which are linked to eye infections and more prominent on the skin - were found in the eyes of non-lens wearers, and researchers do not yet have an explanation for the disparity. Estimates vary, but many cases of potentially scarring bacterial keratitis, or eye inflammation, as well as conjunctival infections occur in contact lens wearers.