Screening for extended-spectrum beta-lactamase Escherichia coli in recreational beach waters in Singapore.

Aims: As part of Singapore's One Health antimicrobial resistance (AMR) management, this work was designed to understand the AMR burden in recreational beach waters using extended-spectrum beta-lactamase Escherichia coli (ESBL-EC) as an indicator. Materials & methods: A total of 90 water samples were collected from six different recreational beaches over three different time periods. Only 28/90 (31.3%) water samples yielded E. coli colonies ranging from 1 to 80 colony-forming units/100 ml. Results & conclusion: Screening of all colonies using CHROMID® ESBL agar and Luria-Bertani broth supplemented with ceftriaxone showed that none was ESBL-EC. Further monitoring is required to understand the prevalence of ESBL-EC spatiotemporally, contributing to the national AMR surveillance program and providing timely risk assessment for exposure to ESBL-EC.

Field trial assessing the antimicrobial decontamination efficacy of gaseous ozone in a public bus setting.

The widespread COVID-19 pandemic caused by the Severe Acute Respiratory Syndrome Coronavirus-2 (SARS-CoV-2) necessitated measures aimed at preventing the spread of SARS-CoV-2. To mitigate the risk of fomite-mediated transmission, environmental cleaning and disinfection regimes have been widely implemented. However, conventional cleaning approaches such as surface wipe downs can be laborious and more efficient and effective disinfecting technologies are needed. Gaseous ozone disinfection is one technology which has been shown to be effective in laboratory studies. Here, we evaluated its efficacy and feasibility in a public bus setting, using murine hepatitis virus (a related betacoronavirus surrogate) and the bacteria Staphylococcus aureus as test organisms. An optimal gaseous ozone regime resulted in a 3.65-log reduction of murine hepatitis virus and a 4.73-log reduction of S. aureus, and decontamination efficacy correlated with exposure duration and relative humidity in the application space. These findings demonstrated gaseous ozone disinfection in field settings which can be suitably translated to public and private fleets that share analogous characteristics.

The impact of saliva collection and processing methods on CRP, IgE, and Myoglobin immunoassays.

BACKGROUND: Owing to its ease of collection, saliva is potentially the sample of choice in diagnosis. Salivary biomolecules have provided a porthole in surveying a person's health and well-being. Our study aims were (1) to demonstrate the effects of pre-analytical steps, collection and pre-processing techniques on salivary protein detection and (2) to establish an indication of salivary reference intervals for 3 biomolecules of clinical interest. METHODS: Saliva samples were collected from participants (n = 25, ages 20-35 years) using the following methods: no stimulation (resting/unstimulated), mechanical, and acid stimulation. The saliva was prepared for analysis by: unprocessed, post standard centrifugation in a container without any additives, and centrifugation using Centrifugal Filter Unit (Amicon® Ultra-0.5). AlphaLisa® assays were used to measure the levels of C-Reactive Protein (CRP), Immunoglobin (IgE) and myoglobin in saliva samples. RESULTS: Saliva flow rates were lowest with the resting/drooling collection method. The lowest total protein concentration was with acid stimulation. Unstimulated and mechanically stimulated collections produced no effect on the CRP and IgE levels while myoglobin levels were highest with the unstimulated collection. Acid stimulation had a negative impact on the measured concentrations of IgE and myoglobin (except for CRP levels). CONCLUSION: Mechanical stimulation was the most viable option for collecting saliva without affecting the levels of CRP and myoglobin. The processing methods had an adverse effect on the concentration of total protein as well as on CRP and IgE concentrations.