Ledwoch K, Said J, Norville P, Maillard J-Y
School of Pharmacy and Pharmaceutical Sciences, Cardiff University, Cardiff, UK.
GAMA Healthcare Ltd, Watford, UK.
Lett Appl Microbiol. 2019 Apr;68(4):329-336. doi: 10.1111/lam.13143.
Dry surface biofilms (DSB) harbouring pathogens are widespread in healthcare settings, are difficult to detect and are resistant to cleaning and disinfection interventions. Here, we describe a practical test protocol to palliate the lack of standard efficacy test methods for DSB. Staphylococcus aureus DSB were produced over a 12-day period, grown with or without the presence of organic matter, and their composition and viability were evaluated. Disinfectant treatment was conducted with a modified ASTM2967-15 test and reduction in viability, transferability and biofilm regrowth post-treatment were measured. Dry surface biofilms produced over a 12-day period had a similar carbohydrates, proteins and DNA content, regardless of the presence or absence of organic matter. The combination of sodium hypochlorite (1000 ppm) and a microfiber cloth was only effective against DSB in the absence of organic load. With the increasing concerns of the uncontrolled presence of DSB in healthcare settings, the development of effective intervention model in the presence of organic load is appropriate for the testing of biocidal products, while the use of three parameters, log reduction, transferability and regrowth, provides an accurate and practical measurement of product efficacy. SIGNIFICANCE AND IMPACT OF THE STUDY: The widespread presence of biofilms on dry surfaces in healthcare settings has been recently documented. These dry surface biofilms (DSB) present an unprecedented challenge to cleaning and disinfection processes. Here, we describe a practical efficacy protocol based on an in vitro Staphylococcus aureus DSB model. The protocol measures reduction in viability, transferability and biofilm regrowth post-treatment to provide altogether a practical assessment of product efficacy against dry surface biofilms.
携带病原体的干表面生物膜（DSB）在医疗环境中广泛存在，难以检测，并且对清洁和消毒干预具有抗性。在此，我们描述了一种实用的测试方案，以缓解DSB缺乏标准功效测试方法的问题。金黄色葡萄球菌DSB在12天内产生，在有或没有有机物存在的情况下生长，并对其组成和活力进行评估。采用改良的ASTM2967 - 15测试进行消毒剂处理，并测量处理后活力、可转移性和生物膜再生长的降低情况。无论有无有机物存在，在12天内产生的干表面生物膜具有相似的碳水化合物、蛋白质和DNA含量。次氯酸钠（1000 ppm）和微纤维布的组合仅在没有有机负荷的情况下对DSB有效。随着对医疗环境中DSB不受控制的存在的日益关注，开发在有有机负荷情况下的有效干预模型适用于测试杀生物产品，而使用对数减少、可转移性和再生长这三个参数可提供对产品功效的准确而实用的测量。研究的意义和影响：最近已记录到生物膜在医疗环境的干燥表面广泛存在。这些干表面生物膜（DSB）对清洁和消毒过程提出了前所未有的挑战。在此，我们描述了一种基于体外金黄色葡萄球菌DSB模型的实用功效方案。该方案测量处理后活力、可转移性和生物膜再生长的降低情况，以全面提供对产品针对干表面生物膜功效的实用评估。
