Direct detection of Borrelia burgdorferi sensu lato bacteria in patient samples for diagnosis of Lyme neuroborreliosis (LNB) is hampered by low diagnostic sensitivity, due to few bacteria in cerebrospinal fluids (CSF) samples. Evaluation of novel molecular methods, including digital PCR (dPCR), as future tools in diagnostics of LNB is desirable. This study aimed to establish a dPCR assay and validate pre-PCR procedures for detection of Borrelia in CSF. Synthetic DNA fragments and cultured Borrelia reference strains were used during optimisation experiments. In addition, 59 CSF specimens from patients examined for LNB were included for clinical validation. The results showed that the pre-PCR parameters with the highest impact on Borrelia-specific dPCR method performance were incubation of the PCR-plate at 4 °C for stabilization of droplets, centrifugation for target concentration, quick-spin for dPCR rain reduction, and PCR inhibition by matrix components. Borrelia DNA in CSF was detected in one out of nine patients with LNB. Diagnostic sensitivity was determined to be 11.1% and specificity 100%. In conclusion, this study reports an optimized Borrelia-specific dPCR method for direct detection of Borrelia in CSF samples. The present study does not support the use of Borrelia-specific dPCR as a routine method for diagnosing LNB.

Background Hospital aquired infections is a considerable challenge for voulnerable patients. Ultraviolet light based on the excitation of mercury emit light at 254nm and has well established anti-microbial effects but the use hereof in populated areas is hindered by the carcinogenic properties of 254nm light. This is in contrast to the recently developed excimer lamps based on Krypton Chloride. These lamps emit light with a peak intensity at a wavelength of 222nm and have recently been demonstrated to have broad bactericidal and viricidal effects includ-ing efficient inactivation of SARS-CoV2. It is, however, unclear how efficiently 222nm lamps perform in a real-life setting such as a hospital waiting area. In this study we aimed to as-sess the antimicrobial efficacy of filtered 222nm excimer lamps in a real-world setting at an out-patient pulmonological clinic. Methods Filtered KrCl 222nm excimer lamps (UV222 lamps) were installed in a densely populated waiting room at the out-patient waiting area at department of Respiratory Diseases and Allergy at Aarhus University Hospital, Aarhus, Denmark. Furniture sufaces were sampled and analyzed for bacterial load in a single arm interventional longitudinal study with and without exposure to filtered 222nm UVC-light. Furthermore, bacterial species were identi-fied using MALDI-ToF mass-spectrometry. Findings The exposure to filtered 222nm UVC-light significantly reduced the number of colony-forming-units, and patches with high desity of bacteria. Pathogenic bacteria such as Staphy-lococcus Aureus and Staphylococcus Epidermidis were detected only in the non-exposed areas suggesting that these species are highly sensitive to inactivation by 222nm UVC-light. Conclusion Filtered 222nm UVC-light is highly anti-microbial in a real-world clinical setting reducing bacterial load and eradicating clinically concerning bacteria species. Filtered 222nm UVC-light has the potential to become an important part of current and future anti-microbial measures in the clinic.

Hospital aquired infections is a considerable challenge for vulnerable patients. Traditional anti-microbial mercury lamps emit light at 254nm and have well established anti-microbial effects. Their use in populated areas is, however, hindered by their carcinogenic properties. This is in contrast to anti-microbial lamps based on krypton chloride (KrCl), demonstrated to have no carcinogenic potential. These lamps emit light with a peak intensity at 222nm and have broad bactericidal and viricidal effects including inactivation of SARS-CoVid-2 in laboratory experiments. Here, we investigate the bactericidal effects of filtered KrCl 222nm excimer lamps (UV222 TM lamps) in an out-patient waiting area at the pulmonology clinic at Aarhus University Hospital. Furniture sufaces were sampled for bacterial load in a single-arm interventional longitudinal study with and without exposure to filtered 222nm UVC-light. Furthermore, bacterial species were identified using MALDI-ToF mass-spectrometry. We found filtered 222nm UVC-light to significantly reduced the number of colony-forming-units. Pathogenic bacteria such as Staphylococcus aureus and Staphylococcus epidermidis were detected only in the non-exposed areas suggesting that these species in particular are highly sensitive to inactivation by 222nm UVC-light. This study demonstrates the potential use of 222nm Far-UVC technology to reduce bacterial load and thus the spread of infectious disease in a hospital setting.