Shi Guang-sen, Boost Maureen, Cho Pauline
School of Optometry, The Hong Kong Polytechnic University, Hung Hom, Kowloon, Hong Kong SAR.
Squina Centre for Infection Control, School of Nursing, The Hong Kong Polytechnic University, Hung Hom, Kowloon, Hong Kong SAR.
Invest Ophthalmol Vis Sci. 2015 May;56(5):3069-74. doi: 10.1167/iovs.15-16550.
To compare isolation of staphylococci from periorbital tissues and accessories of orthokeratology (ortho-k) lens and spectacle wearers and investigate prevalence of antiseptic-resistance (QAC) genes. To determine minimum inhibitory concentrations (MIC) of antiseptics and antibiotic susceptibility of isolates.
Staphylococci were isolated from eyelids, eyelashes, and conjunctival sacs of 23 ortho-k lens wearers and 20 spectacle wearers. Samples were also collected from ortho-k lenses, lens cases, and spectacle frames. Isolations of Staphylococcus aureus were compared between ortho-k subjects and controls for all samples and for coagulase-negative staphylococci (CNS) from conjunctival sacs. QAC genes were amplified in 110 S. aureus and 59 CNS isolates and prevalence compared in isolates from ortho-k lens and spectacle wearers. Associations were assessed between presence of QAC genes and antibiotic and antiseptic susceptibility.
Although isolation of S. aureus did not differ significantly in periorbital samples from ortho-k and control subjects, QAC genes were significantly more common in both S. aureus and CNS from ortho-k subjects (odds ratio 4.4 and 10.74, respectively). Overall, qacA/B was the predominant gene detected, being present in 26.5% CNS and 11% S. aureus. smr and qacH were present in 12% of CNS, but were less common in S. aureus. QAC gene-positive isolates had higher MICs to benzalkonium chloride and chlorhexidine digluconate.
Our results suggest that long-term use of multipurpose solutions containing quaternary ammonium compounds may select for carriage of organisms harboring QAC genes. As these genes are associated with antibiotic resistance, their increased prevalence in isolates from contact lens wearers is a concern.
比较从角膜塑形术（ortho-k）镜片佩戴者和框架眼镜佩戴者的眶周组织及附件中分离葡萄球菌的情况，并调查抗防腐剂（QAC）基因的流行情况。确定防腐剂的最低抑菌浓度（MIC）和分离株的抗生素敏感性。
从23名角膜塑形术镜片佩戴者和20名框架眼镜佩戴者的眼睑、睫毛和结膜囊中分离葡萄球菌。还从角膜塑形术镜片、镜盒和眼镜架上采集样本。比较角膜塑形术受试者和对照组所有样本中金黄色葡萄球菌的分离情况，以及结膜囊中凝固酶阴性葡萄球菌（CNS）的分离情况。在110株金黄色葡萄球菌和59株CNS分离株中扩增QAC基因，并比较角膜塑形术镜片佩戴者和框架眼镜佩戴者分离株中的流行情况。评估QAC基因的存在与抗生素和防腐剂敏感性之间的关联。
虽然角膜塑形术受试者和对照受试者眶周样本中金黄色葡萄球菌的分离情况无显著差异，但角膜塑形术受试者的金黄色葡萄球菌和CNS中QAC基因明显更常见（优势比分别为4.4和10.74）。总体而言，qacA/B是检测到的主要基因，在26.5%的CNS和11%的金黄色葡萄球菌中存在。smr和qacH在12%的CNS中存在，但在金黄色葡萄球菌中较少见。QAC基因阳性分离株对苯扎氯铵和葡萄糖酸洗必泰的MIC较高。
我们的结果表明，长期使用含季铵化合物的多功能护理液可能会选择携带QAC基因的微生物。由于这些基因与抗生素耐药性相关，它们在隐形眼镜佩戴者分离株中的流行率增加令人担忧。
