Potential Use of a Combined Bacteriophage–Probiotic Sanitation System to Control Microbial Contamination and AMR in Healthcare Settings: A Pre-Post Intervention Study

Abstract

Microbial contamination in the hospital environment is a major concern for public health, since it significantly contributes to the onset of healthcare-associated infections (HAIs), which are further complicated by the alarming level of antimicrobial resistance (AMR) of HAI-associated pathogens. Chemical disinfection to control bioburden has a temporary effect and can favor the selection of resistant pathogens, as observed during the COVID-19 pandemic. Instead, probiotic-based sanitation (probiotic cleaning hygiene system, PCHS) was reported to stably abate pathogens, AMR, and HAIs. PCHS action is not rapid nor specific, being based on competitive exclusion, but the addition of lytic bacteriophages that quickly and specifically kill selected bacteria was shown to improve PCHS effectiveness. This study aimed to investigate the effect of such combined probiotic–phage sanitation (PCHSφ) in two Italian hospitals, targeting staphylococcal contamination. The results showed that PCHSφ could provide a significantly higher removal of staphylococci, including resistant strains, compared with disinfectants (−76%, p < 0.05) and PCHS alone (−50%, p < 0.05). Extraordinary sporadic chlorine disinfection appeared compatible with PCHSφ, while frequent routine chlorine usage inactivated the probiotic/phage components, preventing PCHSφ action. The collected data highlight the potential of a biological sanitation for better control of the infectious risk in healthcare facilities, without worsening pollution and AMR concerns.

Probiotic-Based Sanitation in the Built Environment—An Alternative to Chemical Disinfectants

“…Yet, in the past decade, there have been fewer than twenty published peer-reviewed studies investigating the efficacy of PBS in practice (Table 1). Many of these in situ studies were conducted in European hospitals and healthcare settings and used the patented Bacillus-based probiotic cleaning and hygiene system developed by Copma (Ferrara, Italy) [8,69,[71][72][73][74][75][76][77]. All studies identified in Table 1 compared the effectiveness of PBS to conventional chemical disinfectants.…”

“…In addition to the stable reduction in the pathogen burden and associated HAIs, switching from chemical disinfectants to PBS eliminated 50-99.9% of the previously identified resistant bacterial strains on hospital surfaces [74,76]. Abatement of resistant staphylococci strains and other multi-drug resistance bacteria was even more successful when lytic bacteriophages was added to the Bacillus-based probiotic cleaning solution [76,80].…”

“…Likewise, the application of Streptococcus thermophilus and Streptococcus mitis have been shown to significantly reduce the in vitro colonization of S. aureus and C. albicans on rubber, silicone and glass surfaces [101,104]. Thus, investing in the development and evaluation of diverse PBS consortiums and formulations, such as those containing bacteriophages [76,80,91], lactic acid bacteria and photosynthetic microbes [105], could prove worthwhile, as long as quality control and assurance is upheld. An analysis of 14 commercial probiotic cleaners identified the presence of several opportunistic bacterial pathogens in the product preparations [106].…”

Biocontrol in built environments to reduce pathogen exposure and infection risk

“…A larger follow-up study at two hospitals using the combined PCHS+Phage treatment had mixed results. One hospital showed a significant reduction in Staphylococcus , but the other did not [ 24 ]. This study was performed during the COVID-19 pandemic, which led to the use of emergency applications of 3% NaClO disinfectant.…”

“…This study was performed during the COVID-19 pandemic, which led to the use of emergency applications of 3% NaClO disinfectant. One hospital used a greater number of NaClO applications, and this increase was correlated with an order of magnitude reduction in Bacillus and phage abundance, likely leading to a reduction in the effectiveness of the probiotic intervention [ 24 ]. These results support an earlier study, also performed during the COVID-19 pandemic, that found a reduction in pathogen load through the use of PCHS was reversed when emergency 5% NaClO was implemented [ 91 ].…”