Source avec lien : The Journal of Hospital Infection, Prépublication. 10.1016/j.jhin.2023.11.004
Alors que les biofilms standard ont fait l’objet d’études approfondies depuis plus de 50 ans, les biofilms de surface sèche (DSB) sont peu connus. Cette étude systématique vise à déterminer si les bactéries présentes dans les DSB sont viables, cultivables et dénombrables.
BACKGROUND: Bacteria are known to live inside architectural structures called biofilms. While standard biofilms have been studied extensively for over 50 years, little is known about the dry surface biofilms (DSBs). Since 2012, DSBs have been described in several scientific papers, but basic knowledge about the viability and culturability of bacteria remains limited. AIM: We conducted a systematic review which aimed to determine whether bacteria inside DSBs are viable, culturable and enumerable. METHODS: Eligible articles had to deal with DSBs containing at least one bacterial species involved in healthcare associated infections, which developed in actual healthcare environments (in situ) or with the help of any biofilm model (in vitro). FINDINGS: 24 articles were included in the review. Whilst most of them isolated viable bacteria (87% in situ; 100% in vitro), no in situ study quantified culturable bacteria in the biofilm per unit area. Conversely, 100% of in vitro studies cultured the bacteria from controls and 94.4% gave an enumeration of them. Culturable bacteria also grew after 78% of the cleaning, disinfection or sterilization protocols tested. Microscopic observations after staining the samples with live/dead fluorescent probes (Baclight®), showed large amounts of viable cells in culture-negative samples. CONCLUSION: Our study questions the efficacy of current methods for microbiological monitoring of surfaces since these methods are only based on bacterial culturability. To improve both surface monitoring and cleaning and disinfection protocols, it is necessary to integrate the concept of DSBs which appears to contain a significant amount of viable but non-culturable bacteria.