Journal of Hospital Infection最新文献

For Clostridioides difficile infection (CDI), faecal microbiota transplantation (FMT) is currently recommended for patients with three or more CDI episodes. A recent randomised controlled trial (RCT) show that FMT may be considered early, defined as intervention during the first or second CDI episode. Compared with standard care for first or second CDI, patients randomised to FMT had €1,645 lower hospital costs over 26 weeks owing to fewer admissions and hospital contacts and less medication use.

Disinfectants are a critical infection control measure that are relied upon globally in a range of settings including healthcare, food production, and domestic environments. However, bacteria have been shown to survive disinfectant treatments when harboured in dry surface biofilms or when disinfectants are used ineffectively. This provides an opportunity for organisms to develop low-level tolerance to various disinfectants. The capability of bacteria to develop adaptations to non-antibiotic antimicrobial agents is often overlooked. This study investigates the ability of Klebsiella pneumoniae NDM-1 strain NCTC 13443 to adapt to a range of common chemical disinfectants (benzalkonium chloride, didecyldimethylammonium chloride, polyhexamethylene biguanide, chlorocresol and bronopol) via serial passage exposure method. After long-term adaptation K. pneumoniae developed tolerance to all tested disinfectants, exhibiting a minimum inhibitory concentration increase of between 30-413% compared to the untreated parent samples. Characterisation of disinfectant cross-tolerance showed that while cross-tolerance can occur, most adapted samples became more susceptible to the second disinfectant treatment, likely because of the fitness cost of adaptation. Observed cross-tolerance/increased susceptibility was not always reciprocated between disinfectant-tolerant samples, indicating that the order of disinfectant exposure is important during tolerance development. This has significant implications for disinfectant cleaning routines, and is likely due to variations in the underpinning tolerance mechanisms, even when the disinfectants display similar mechanisms of action. This study reports the capability and readiness of clinically relevant K. pneumoniae to adapt to common disinfectants that are relied upon every day across the world, delivering much-needed insights into an often-overlooked aspect of antimicrobial resistance.

Background: Ozonated water is expected to be an effective disinfectant for SARS-CoV-2 present on environmental fomites; however, ozone is consumed by organic substances, resulting in attenuation of its effect. SARS-CoV-2 present in saliva can contaminate environmental surfaces; therefore, it is essential to understand the effect of organic substances in saliva on the disinfectant properties of ozonated water.

Aim: To assess organic factors in saliva and the extent to which they diminish the effect of ozonated water on SARS-CoV-2.

Methods: Ozonated water was exposed to salivary organic factors and residual ozone concentrations were measured. SARS-CoV-2 was exposed to a salivary factor and virus inactivation by ozonated water was measured.

Findings: Amylase and mucin consumed ozone in a concentration-dependent manner. Urea did not. Ozonated water appeared to inactivate SARS-CoV-2 within 30 sec. The amount of inactivated SARS-CoV-2 decreased as the protein concentration increased. Virus inactivation was stronger by 1.5 mg/L ozonated water than by 0.5 mg/L ozonated water.

Conclusion: This study suggests that the salivary amylase and mucin decay ozone in a concentration-dependent manner, thereby attenuating the disinfection properties of ozonated water for SARS-CoV-2. An increase of the initial amount of ozone can ameliorate the disinfection effect of ozonated water on SARS-CoV-2. Ozone consumption should be taken into consideration for virus infection control. These results provide fundamental information about the effect of ozonated water when used to decontaminate surfaces harbouring SARS-CoV-2 in saliva.