School of Pharmacy and Pharmaceutical Sciences, Cardiff University, Cardiff, United Kingdom.
GAMA Healthcare, Watford, United Kingdom.
Infect Control Hosp Epidemiol. 2021 Dec;42(12):1486-1492. doi: 10.1017/ice.2021.42. Epub 2021 Mar 2.
The abundance and prevalence of dry-surface biofilms (DSBs) in hospitals constitute an emerging problem, yet studies rarely report the cleaning and disinfection efficacy against DSBs. Here, the combined impact of treatments on viability, transferability, and recovery of bacteria from DSBs has been investigated for the first time.
Staphylococcus aureus DSBs were produced in alternating 48-hour wet-dry cycles for 12 days on AISI 430 stainless steel discs. The efficacy of 11 commercially available disinfectants, 4 detergents, and 2 contactless interventions were tested using a modified standardized product test. Reduction in viability, direct transferability, cross transmission (via glove intermediate), and DSB recovery after treatment were measured.
Of 11 disinfectants, 9 were effective in killing and removing bacteria from S. aureus DSBs with >4 log10 reduction. Only 2 disinfectants, sodium dichloroisocyanurate 1,000 ppm and peracetic acid 3,500 ppm, were able to lower both direct and cross transmission of bacteria (<2 compression contacts positive for bacterial growth). Of 11 disinfectants, 8 could not prevent DSB recovery for >2 days. Treatments not involving mechanical action (vaporized hydrogen peroxide and cold atmospheric plasma) were ineffective, producing <1 log10 reduction in viability, DSB regrowth within 1 day, and 100% transferability of DSB after treatment.
Reduction in bacterial viability alone does not determine product performance against biofilm and might give a false sense of security to consumers, manufacturers and regulators. The ability to prevent bacterial transfer and biofilm recovery after treatment requires a better understanding of the effectiveness of biocidal products.
医院中干燥表面生物膜（DSB）的丰度和流行率构成了一个新出现的问题，但研究很少报告针对 DSB 的清洁和消毒效果。在这里，首次研究了处理方法对 DSB 中细菌的生存能力、可转移性和回收能力的综合影响。
在 AISI 430 不锈钢盘上，通过 48 小时干湿交替周期，在 12 天内产生金黄色葡萄球菌 DSB。使用改进的标准化产品测试，测试了 11 种市售消毒剂、4 种清洁剂和 2 种非接触干预措施的效果。测量处理后的生存能力、直接可转移性、交叉传播（通过手套中介）和 DSB 回收的减少。
在 11 种消毒剂中，有 9 种能够有效杀死和去除金黄色葡萄球菌 DSB 中的细菌，减少了>4 对数。只有两种消毒剂，二氯异氰尿酸钠 1000ppm 和过氧乙酸 3500ppm，能够降低细菌的直接和交叉传播（<2 个压缩接触部位有细菌生长阳性）。在 11 种消毒剂中，有 8 种不能防止 DSB 在>2 天内恢复。不涉及机械作用的处理（汽化过氧化氢和冷等离体等离子体）无效，仅使生存能力降低<1 对数，1 天内 DSB 重新生长，处理后 DSB 的可转移性为 100%。
仅降低细菌的生存能力并不能确定产品对生物膜的性能，这可能会给消费者、制造商和监管机构带来一种虚假的安全感。在处理后防止细菌转移和生物膜恢复的能力需要更好地了解杀菌产品的有效性。
