中国热带地区真菌性角膜溃疡致病菌种类及药物敏感性分析

Analysis of causative genus of keratomycosis and antifungal susceptibility in tropical area of China

背景海南省处于中国热带和亚热带地区，全年的气候特点适宜真菌生长繁殖，该地区真菌感染性眼病发病率较高，分析致病菌并了解其敏感药物对感染性眼病的临床治疗有重要意义。 目的探讨中国海南省及其南海诸岛屿热带地区真菌性角膜溃疡致病菌种类及其对临床常用抗真菌药物的敏感性。 方法采用系列病例观察研究方法，收集2014年2月至2016年5月在中山大学中山眼科中心海南眼科医院诊断为真菌性角膜溃疡者174例174眼，所有患者均来自海南省及其南海诸岛屿热带地区，诊断方法参照《眼科学》（第五版）中的标准。无菌条件下刮取角膜溃疡的进展缘或基底部的菌丝苔被，采用KOH湿片法直接涂片行真菌检查；将采集的标本接种于马铃薯葡萄糖琼脂培养基和沙氏培养基进行真菌培养，对培养出的82株致病性真菌参照《全国临床检验操作规程》（第3版）和《实用临床微生物学检验与图谱》进行菌种鉴定，采用纸片扩散法对分离的菌株行10种抗真菌药物的药物敏感性试验。 结果涂片镜检的126例中可见菌丝和孢子者34例，阳性率为27.0%；真菌培养的174例标本中培养出致病性真菌82株，阳性率为47.1%，主要致病性真菌依次为镰刀菌属、不产孢子菌、曲霉属和茎点霉属，分别占47.5%、12.2%、9.8%和9.8%。行药物敏感性试验的77株真菌对制霉菌素、两性霉素B和特比萘芬敏感性较好，敏感率分别为88.3%、72.7%和71.4%。 结论中国海南省及南海诸岛屿热带地区真菌性角膜溃疡的主要致病菌为镰刀菌属、不产孢子菌、曲霉属和茎点霉属，这些致病真菌对制霉菌素、两性霉素B和特比萘芬的敏感性较高。

BackgroundHainan Island is a tropical and subtropical area in China, with a suitable climate for fungal growth and breeding.Keratomycosis occurred frequently in this area.It is essential to analyze the causative genus and investigate the sensitive drugs prior to the clinical treatment of fungal keratitis. ObjectiveThis study attempted to analyze the fungal population of fungal corneal ulcer patients in Hainan Island of China and examine the susceptibility of antifungal drugs. MethodsA series cases observational study was carried out.One hundred and seventy-four eyes of 174 fungal corneal ulcer patients were enrolled in Hainan Eye Hospital from February 2014 to May 2016 based on the diagnosis criteria in Ophthalmology.The specimens at corneal lesions were collected under the aseptic conditions, and fungus was examined by KOH based smear.Mycological culture was performed with potato-dextrose agar and Sabourand＇s agar.The 82 cultured causative strains were identified to characterize the spectrum of the species associated with keratitis infections in Hainan Province.Susceptibilities of these causative strains to ten antifungals were determined in vitro by slip diffusion method. ResultsBy smear microscopy, fungal hyphae and spores were found in 34 specimens of 126 patients, with the positive rate 27.0%.In 174 specimens of fungal culture, 82 strains of fungi were found, with the positive rate 47.1%, and typing results revealed that the isolates were distributed among species in the fusarium （47.5%）, non-spore fungus （12.2%）, aspergillus （9.8%） and phoma （9.8%）. Nystatin was proved to be the most effective drug to 77 strains of antifungal drug susceptibility, followed by amphotericin B and terbinafine, with the susceptibility of 88.3%, 72.7%, and 71.4%, respectively. ConclusionsFusarium species, non-spore fungus, aspergillus, and phoma are common pathogenic fungi of keratomycosis around Hainan Island in China, and nystatin, amphotericin B and terbinafine are efficient in the treatment of the fungal corneal ulcer.