Todokoro Daisuke, Eguchi Hiroshi, Suzuki Takashi, Suzuki Motoo, Nakayama-Imaohji Haruyuki, Kuwahara Tomomi, Nomura Takahiro, Tomita Haruyoshi, Akiyama Hideo
Department of Ophthalmology, Gunma University Graduate School of Medicine, 3-39-15 Showa-machi, Maebashi, Gunma, 371-8511, Japan.
Department of Ophthalmology, Kindai University, Osaka, Japan.
Jpn J Ophthalmol. 2018 Nov;62(6):699-705. doi: 10.1007/s10384-018-0630-5. Epub 2018 Oct 15.
Enterococcus faecalis causes severe acute endophthalmitis and often leads to poor visual outcomes. Conjunctival bacterial cultures occasionally grow atypical bacteria including E. faecalis, which can potentially contribute to the development of postoperative endophthalmitis. However, the characteristics of these ocular E. faecalis strains are unknown. This study is the first attempt to determine the population characteristics of E. faecalis clinical isolates from eye infections and ocular commensals.
Retrospective METHODS: Twenty-eight E. faecalis ocular isolates were collected from 23 patients at 3 referring hospitals. The multilocus sequence typing (MLST) data were analyzed using the eBURST program. Phenotypes of cytolysin and gelatinase, antibiotic susceptibility, and mutations of the quinolone resistance-determining regions (QRDRs) of gyrA and parC were also examined. Pulsed-field gel electrophoresis (PFGE) was performed for strains from the same patients.
PFGE revealed that 3 patients retained identical strains for 10 months to 2 and a half years. MLST identified 12 sequence types (STs), which were clustered into 3 clonal complexes (CCs) and 8 singletons, with ST179 the largest. Thirteen of the 23 isolates (56.5%) belonged to CC58, CC8, or CC2, which have previously been reported to be major CCs. Six of the 23 strains (26.0%) exhibited high-level quinolone resistance derived from mutations of the QRDRs in both gyrA and parC.
The sequence types of E. faecalis ocular isolates were divergent, with no eye-specific lineages observed. Persistent colonization of E. faecalis on the ocular surface was demonstrated in patients with chronic ocular surface diseases.
粪肠球菌可引起严重的急性眼内炎，常导致视力预后不良。结膜细菌培养偶尔会培养出包括粪肠球菌在内的非典型细菌，这可能会促进术后眼内炎的发生。然而，这些眼部粪肠球菌菌株的特征尚不清楚。本研究首次尝试确定眼部感染和眼部共生菌中粪肠球菌临床分离株的群体特征。
回顾性研究
从3家转诊医院的23例患者中收集了28株粪肠球菌眼部分离株。使用eBURST程序分析多位点序列分型（MLST）数据。还检测了细胞溶素和明胶酶的表型、抗生素敏感性以及gyrA和parC喹诺酮耐药决定区（QRDRs）的突变。对来自同一患者的菌株进行脉冲场凝胶电泳（PFGE）。
PFGE显示，3例患者在10个月至2年半的时间内保留了相同的菌株。MLST鉴定出12种序列类型（STs），它们被聚类为3个克隆复合体（CCs）和8个单态，其中ST179最大。23株分离株中有13株（56.5%）属于CC58、CC8或CC2，这些此前已被报道为主要的CCs。23株菌株中有6株（26.0%）表现出高水平喹诺酮耐药性，这是由gyrA和parC中QRDRs的突变引起的。
粪肠球菌眼部分离株的序列类型各不相同，未观察到眼部特异性谱系。在慢性眼表疾病患者中证实了粪肠球菌在眼表的持续定植。
