High Prevalence of Biofilm-Forming MRSA in the Conjunctival Flora in Chronic Dacryocystitis
High Prevalence of Biofilm-Forming MRSA in the Conjunctival Flora in Chronic Dacryocystitis
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DOI：
10.1080/08820538.2019.1578382
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发表时间：
2019-02-17
影响因子：
1.7
通讯作者：
Basu, Soumyava
中科院分区：
文献类型：
--
作者：
Mitra, Sanchita;Chayani, Nirupama;Basu, Soumyava
目的：报告慢性泪囊炎患者结膜植物群的微生物谱和生物膜形成耐甲氧西林金黄色葡萄球菌（MRSA）的患病率。设计：前瞻性病例对照研究。方法：我们纳入了单侧慢性泪囊炎患者，并以其健眼作为对照。通过标准微生物学程序测定分离株的微生物学特征和抗生素敏感性。S.通过苯唑西林抗性筛选琼脂法和mecA聚合酶链反应（PCR）进一步评价金黄色葡萄球菌分离株的甲氧西林抗性，并通过刚果红琼脂法、微量滴定板（MTP）测定以及伊卡A和伊卡D PCR进一步评价金黄色葡萄球菌分离株的生物膜合成。结果：发现单侧慢性泪囊炎95例。需氧革兰阳性菌（74.2%，n = 72）多于革兰阴性菌（25.7%，n = 25）和厌氧菌（20.5%，n = 25）。S.金黄色葡萄球菌最常见（46.4%，n = 45），其次是铜绿假单胞菌（10.3%，n = 10）。革兰氏阳性分离株对利奈唑胺（100%）和更高代氟喹诺酮类药物的敏感性最高。革兰阴性菌对所有抗生素均表现出良好的敏感性（>90%）。S.苯唑西林耐药琼脂平板法和mecA PCR法检测MRSA的阳性率分别为93.5%和96.9%。MTP检测发现71.8%的MRSA分离株形成生物膜，58.1%的MRSA分离株对≥ 3类抗生素耐药。结论：革兰氏阳性菌，特别是S。金黄色葡萄球菌是慢性泪囊炎的主要病原体。在这些分离株中MRSA的流行率很高，并同时形成生物膜。
Objectives: To report the microbiological spectrum of conjunctival flora and prevalence of biofilm-forming Methicillin-resistant Staphylococcus aureus (MRSA) in conjunctival flora in chronic dacryocystitis. Design: Prospective, case-control study. Methods: We included patients with unilateral chronic dacryocystitis, and their unaffected eyes as control. Microbiological profile and antibiotic susceptibility of the isolates was determined by standard microbiological procedures. S. aureus isolates were further evaluated for Methicillin resistance by Oxacillin resistance screening agar method and mecA polymerase chain reaction (PCR) and for biofilm synthesis by Congo red agar method, Microtitre plate (MTP) assay, and ica A and ica D PCR. Results: We found 95 patients with unilateral chronic dacryocystitis. Aerobic Gram-positive isolates (74.2%, n = 72) were more than Gram-negative (25.7%, n = 25) or anaerobic isolates (20.5%, n = 25). S. aureus was most common (46.4%, n = 45), followed by Pseudomonas aeruginosa (10.3%, n = 10). Gram-positive isolates showed highest sensitivity to Linezolid (100%) and higher generation fluoroquinolones. Gram-negative isolates showed good sensitivity (>90%) to all tested antibiotics. S. aureus isolates showed MRSA prevalence as 93.5% and 96.9% by Oxacillin resistance screening agar method and mecA PCR, respectively. Biofilm formation was found in 71.8% MRSA isolates by MTP assay and 58.1% MRSA isolates were resistant to >= 3 classes of antibiotics. Conclusions: Gram-positive organisms, specifically S. aureus, are the major etiological agent in chronic dacryocystitis. There is high prevalence of MRSA in these isolates and concurrent biofilm formation.