Cornea & Anterior Segment Service, LV Prasad Eye Institute, Bhubaneswar, Odisha, India.
Ocular Microbiology Service, LV Prasad Eye Institute, Bhubaneswar, Odisha, India.
Graefes Arch Clin Exp Ophthalmol. 2021 Jul;259(7):1925-1933. doi: 10.1007/s00417-021-05109-z. Epub 2021 Mar 2.
To compare ocular surface microbiome and its antibiotic sensitivity in vernal keratoconjunctivitis (VKC) with normal ocular surface.
In this case-control study, thirty patients each with clinical diagnosis of VKC and age-matched controls with normal ocular surface were enrolled. Tear film samples were collected from each group and subjected to microbial evaluation with microscopy, conventional culture methods, and polymerase chain reaction (PCR). Microbial diversity and antibiotic sensitivity patterns were analyzed.
Most patients (67%) belonged to severe grades (3 and 4) of VKC, and allergic history could be elicited in 20%. On culture, bacteria were isolated in 50% of VKC patients and 47% of control group. Staphylococcus species were identified in 70% VKC group and 57% control group. S. aureus growth was seen in 52% and 21% of VKC patients and controls, respectively. S. pneumoniae was isolated only in controls (29%) (p<0.05). Confluent colonies (≥10 colonies/μl) were seen in 70% of VKC patients and 14% of controls (p<0.05). Fluoroquinolone resistance was more among higher grades of VKC (50%) (p<0.01) and was observed in 46% of VKC patients and 23% of control group (p<0.01). Both groups were negative for HSV-1 DNA and fungal growth.
Staphylococcus, the most common ocular surface flora, was predominant in VKC patients. Microbial analysis revealed similar microbial diversity in both groups. However, bacterial load was higher in VKC. Increased fluoroquinolone resistance was observed in VKC patients with more resistance among higher grades. Fungi and HSV-1 were not seen in VKC or normal ocular surface.
比较春季角结膜炎（VKC）与正常眼表的眼表微生物组及其抗生素敏感性。
在这项病例对照研究中，纳入了 30 例临床诊断为 VKC 的患者和年龄匹配的正常眼表对照组患者。从每组收集泪膜样本，并通过显微镜检查、常规培养方法和聚合酶链反应（PCR）进行微生物评估。分析微生物多样性和抗生素敏感性模式。
大多数患者（67%）属于 VKC 的严重等级（3 和 4 级），20%可引出过敏史。在培养中，50%的 VKC 患者和 47%的对照组分离出细菌。VKC 组 70%和对照组 57%鉴定为葡萄球菌属。金黄色葡萄球菌生长分别见于 52%和 21%的 VKC 患者和对照组（p<0.05）。仅在对照组（29%）中分离出肺炎链球菌（p<0.05）。VKC 患者中有 70%出现融合菌落（≥10 个菌落/μl），而对照组中只有 14%（p<0.05）。更高等级的 VKC 中（50%）观察到氟喹诺酮类药物耐药性更高（p<0.01），并且在 46%的 VKC 患者和 23%的对照组中观察到（p<0.01）。两组均未检测到 HSV-1 DNA 和真菌生长。
葡萄球菌是最常见的眼表菌群，在 VKC 患者中占优势。微生物分析显示两组的微生物多样性相似。然而，VKC 患者的细菌负荷更高。在 VKC 患者中观察到氟喹诺酮类药物耐药性增加，且在较高等级中耐药性更高。VKC 或正常眼表均未检测到真菌和 HSV-1。
