High-level tolerance to triclosan may play a role in Pseudomonas aeruginosa antibiotic resistance in immunocompromised hosts: evidence from outbreak investigation.
High-level tolerance to triclosan may play a role in Pseudomonas aeruginosa antibiotic resistance in immunocompromised hosts: evidence from outbreak investigation.
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DOI：
10.1186/1756-0500-5-43
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发表时间：
2012-01-19
影响因子：
1.8
通讯作者：
Visca P
中科院分区：
文献类型：
--
作者：
D'Arezzo S;Lanini S;Puro V;Ippolito G;Visca P
铜绿假单胞菌是免疫功能低下患者的主要感染威胁。我们最近报告了一个致命的流行病的多药耐药铜绿假单胞菌在肿瘤科单位，与大量污染的三氯生为基础的消毒剂。本研究的目的是评估三氯生和氯己定二葡萄糖酸盐对铜绿假单胞菌流行株的抗菌活性，以证实肥皂分配器在爆发期间作为持续感染源的假设，并探讨三氯生在增加对选定抗生素的耐药性水平方面的潜在作用。分别使用含有三氯生和氯己定二葡萄糖酸盐的两种商业制剂进行消毒剂的敏感性试验和时间杀灭试验。采用微量肉汤稀释法进行药敏试验。铜绿假单胞菌流行株对三氯生的耐药性极高（表观MIC = 2，125 mg/L），而对二葡萄糖酸氯己定明显敏感（表观MIC = 12.5 mg/L）。在逐渐适应三氯生后，流行菌株在存在3，400 mg/L（相当于1.6 × MIC）三氯生的情况下存活了很长时间（> 120 h），同时增加了对6种抗生素的耐药性，这些抗生素是耐药菌群家族药物外排泵的典型底物。这种作用被外排泵抑制剂逆转。流行性铜绿假单胞菌菌株对三氯生具有耐药性，其先前暴露于三氯生增加了抗生素耐药性，可能是通过主动外排机制。由于铜绿假单胞菌可以耐受较高的三氯生浓度，因此在接待铜绿假单胞菌感染高风险患者的医疗机构中应避免使用含三氯生的消毒剂。
Pseudomonas aeruginosa is a major infectious threat to immunocompromised patients. We recently reported a fatal epidemic of multidrug-resistant P. aeruginosa in an onchoematology unit, linked to massive contamination of a triclosan-based disinfectant. The aim of this study is to evaluate the antimicrobial activity of triclosan and chlorhexidine digluconate against the epidemic strain of P. aeruginosa, to confirm the hypothesis that the soap dispenser acted as a continuous source of the infection during the outbreak, and to explore the potential role of triclosan in increasing the level of resistance to selected antibiotics. Susceptibility tests and time-kill assays for disinfectans were performed using two commercial formulations containing triclosan and chlorhexidine digluconate, respectively. Antibiotic susceptibility testing was performed by the broth microdilution method. The P. aeruginosa epidemic strain exhibited an extremely high level of triclosan resistance (apparent MIC = 2,125 mg/L), while it was markedly susceptible to chlorhexidine digluconate (apparent MIC = 12.5 mg/L). Upon gradual adaptation to triclosan, the epidemic strain survived for a long period (> 120 h) in the presence of 3,400 mg/L (equivalent to 1.6 × MIC) of triclosan, concomitantly increasing the resistance to six antibiotics that are typical substrates of drug efflux pumps of the resistance nodulation division family. This effect was reversed by efflux pump inhibitors. The epidemic P. aeruginosa strain was resistant to triclosan and its previous exposure to triclosan increases antibiotic resistance, likely through active efflux mechanisms. Since P. aeruginosa can become tolerant to elevated triclosan concentrations, the use of triclosan-based disinfectants should be avoided in those healthcare settings hosting patients at high risk for P. aeruginosa infection.