Purpose: 

The objective of this study was to compare the clinical and microbiological profiles of culture-proven pure Corynebacterium keratitis with mixed infection and their antibiotic susceptibility patterns over a 2-year period.

Methods: 

A retrospective analysis of culture-proven cases of Corynebacterium keratitis over a 2-year period was performed in 3 different tertiary eye care centers. All isolates were tested for antibiotic susceptibility in vitro using the disc-diffusion method for 7 antibiotics.

Results: 

Altogether 108 cases were identified as culture-positive Corynebacterium keratitis in 3 tertiary eye care centers. Of these, 60.2% (n = 65) and 39.8% (n = 43) of cases were due to pure Corynebacterium and mixed infection, respectively. The mean duration of symptoms was 23.2 ± 29.6 days. In the mixed-infection group, fungus was identified as the coexistent pathogen in 22 cases (51.1%). Ocular surface disorder was the most common risk factor (33.9%) in Corynebacterium keratitis. The most frequently isolated species was Corynebacterium amycolatum (22.2%) in both groups. Therapeutic keratoplasty was performed in 8.3% of cases. There was no significant difference in the outcome between the 2 groups. Cefazolin resistance was seen in 13.9% of patients, and all isolates were susceptible to vancomycin. The resistance pattern showed emerging resistance toward fluoroquinolone because the isolates were resistant to gatifloxacin (58.3%), moxifloxacin (47.2%), ciprofloxacin (54.6%), and ofloxacin (45.4%).

Conclusions: 

Ocular surface disorder is the most common risk factor in Corynebacterium keratitis. Although fluoroquinolones are commonly used as first-line therapy in microbial keratitis, the in vitro resistance pattern indicates that these are less likely to be effective in infection with Corynebacterium species.

中文翻译：

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棒状杆菌角膜炎：纯感染与混合感染以及不同三级眼保健中心的抗生素敏感性模式

目的： 

本研究的目的是比较经过培养证明的纯棒状杆菌角膜炎混合感染的临床和微生物学特征及其两年内的抗生素敏感性模式。

方法： 

在 3 个不同的三级眼保健中心对两年内经培养证实的棒状杆菌角膜炎病例进行了回顾性分析。使用纸片扩散法对 7 种抗生素对所有分离株进行了体外抗生素敏感性测试。

结果： 

3 个三级眼保健中心共鉴定出 108 例棒状杆菌角膜炎培养阳性病例。其中，60.2%（n = 65）和39.8%（n = 43）的病例分别是由纯棒状杆菌和混合感染引起的。症状平均持续时间为 23.2 ± 29.6 天。混合感染组中，真菌为共存病原菌22例（51.1%）。眼表疾病是棒状杆菌角膜炎最常见的危险因素（33.9%）。两组中最常见的分离菌种是无分枝棒状杆菌（22.2%）。8.3% 的病例进行了治疗性角膜移植术。两组之间的结果没有显着差异。13.9% 的患者出现头孢唑林耐药，所有分离株均对万古霉素敏感。耐药模式显示出对氟喹诺酮类药物的新耐药性，因为分离株对加替沙星 (58.3%)、莫西沙星 (47.2%)、环丙沙星 (54.6%) 和氧氟沙星 (45.4%) 耐药。

结论： 

眼表疾病是棒状杆菌角膜炎最常见的危险因素。尽管氟喹诺酮类药物通常用作微生物性角膜炎的一线治疗，但体外耐药模式表明这些药物对棒状杆菌感染不太可能有效。