The Antibacterial Efficacy of Far-UVC Light: A Combined-Method Study Exploring the Effects of Experimental and Bacterial Variables on Dose-Response.

Far-ultraviolet C light, with a wavelength of 200-230 nm, has demonstrated broad-spectrum germicidal efficacy. However, due to increased interest in its use as an alternative antimicrobial, further knowledge about its fundamental bactericidal efficacy is required. This study had two objectives. Firstly, it investigated experimentally the Far-UVC dose-response of common bacteria suspended at various cell densities in transparent buffer, ensuring no influence from photosensitive suspending media. Increasing doses of Far-UVC were delivered to Enterococcus faecium, Escherichia coli, Pseudomonas aeruginosa and Staphylococcus aureus in PBS at 101, 102, 103, 105 and 107 CFU·mL-1, with surviving colony-forming units enumerated (n ≥ 3). Secondly, through a systematised literature review, this work sought to explore the impact of genus/species, Gram type, cell form, cell density and irradiance on dose-response. The screening of 483 publications was performed with 25 included in the study. Data for 30 species were collated, analysed and compared with the experimental results. Overall, Gram-positive species showed greater resilience to Far-UVC than Gram-negative; some inter-species and inter-genera differences in resilience were identified; endospores were more resilient than vegetative cells; the results suggested that inactivation efficiency may decrease as cell density increases; and no significant correlation was identified between irradiance and bactericidal dose effect. In conclusion, this study has shown Far-UVC light to be an effective decontamination tool against a vast range of bacterial vegetative cells and endospores.

Bringing optimised COVID-19 vaccine schedules to immunocompromised populations (BOOST-IC): study protocol for an adaptive randomised controlled clinical trial.

BACKGROUND: Immunocompromised hosts (ICH) experience more breakthrough infections and worse clinical outcomes following infection with COVID-19 than immunocompetent people. Prophylactic monoclonal antibody therapies can be challenging to access, and escape variants emerge rapidly. Immunity conferred through vaccination remains a central prevention strategy for COVID-19. COVID-19 vaccines do not elicit optimal immunity in ICH but boosting, through additional doses of vaccine improves humoral and cellular immune responses. This trial aims to assess the immunogenicity and safety of different COVID-19 vaccine booster strategies against SARS-CoV-2 for ICH in Australia. METHODS: Bringing optimised COVID-19 vaccine schedules to immunocompromised populations (BOOST-IC) is an adaptive randomised trial of one or two additional doses of COVID-19 vaccines 3 months apart in people living with HIV, solid organ transplant (SOT) recipients, or those who have haematological malignancies (chronic lymphocytic leukaemia, non-Hodgkin lymphoma or multiple myeloma). Key eligibility criteria include having received 3 to 7 doses of Australian Therapeutic Goods Administration (TGA)-approved COVID-19 vaccines at least 3 months earlier, and having not received SARS-CoV-2-specific monoclonal antibodies in the 3 months prior to receiving the study vaccine. The primary outcome is the geometric mean concentration of anti-spike SARS-CoV-2 immunoglobulin G (IgG) 28 days after the final dose of the study vaccine. Key secondary outcomes include anti-spike SARS-CoV-2 IgG titres and the proportion of people seroconverting 6 and 12 months after study vaccines, local and systemic reactions in the 7 days after vaccination, adverse events of special interest, COVID-19 infection, mortality and quality of life. DISCUSSION: This study will enhance the understanding of COVID-19 vaccine responses in ICH, and enable the development of safe, and optimised vaccine schedules in people with HIV, SOT, or haematological malignancy. TRIAL REGISTRATION: ClinicalTrials.gov NCT05556720. Registered on 23rd August 2022.

Smartphone-based optical sectioning (SOS) microscopy with a telecentric design for fluorescence imaging.

We propose a smartphone-based optical sectioning (SOS) microscope based on the HiLo technique, with a single smartphone replacing a high-cost illumination source and a camera sensor. We built our SOS with off-the-shelf optical, mechanical cage systems with 3D-printed adapters to seamlessly integrate the smartphone with the SOS main body. The liquid light guide can be integrated with the adapter, guiding the smartphone's LED light to the digital mirror device (DMD) with neglectable loss. We used an electrically tuneable lens (ETL) instead of a mechanical translation stage to realise low-cost axial scanning. The ETL was conjugated to the objective lens's back pupil plane (BPP) to construct a telecentric design by a 4f configuration to maintain the lateral magnification for different axial positions. SOS has a 571.5 µm telecentric scanning range and an 11.7 µm axial resolution. The broadband smartphone LED torch can effectively excite fluorescent polystyrene (PS) beads. We successfully used SOS for high-contrast fluorescent PS beads imaging with different wavelengths and optical sectioning imaging of multilayer fluorescent PS beads. To our knowledge, the proposed SOS is the first smartphone-based HiLo optical sectioning microscopy (£1965), which can save around £7035 compared with a traditional HiLo system (£9000). It is a powerful tool for biomedical research in resource-limited areas.

Immunogenicity, effectiveness, and safety of SARS-CoV-2 vaccination in people with HIV.

OBJECTIVES: People with HIV (PWH) experience a greater risk of morbidity and mortality following COVID-19 infection, and poorer immunological responses to several vaccines. We explored existing evidence regarding the immunogenicity, effectiveness, and safety of SARS-CoV-2 vaccines in PWH compared with controls. METHODS: We conducted a systematic search of electronic databases from January 2020 until June 2022, in addition to conference databases, to identify studies comparing clinical, immunogenicity, and safety in PWH and controls. We compared results between those with low (<350 cells/µl) and high (>350 cells/µl) CD4 + T-cell counts where possible. We performed a meta-analysis of seroconversion and neutralization responses to calculate a pooled risk ratio as the measure of effect. RESULTS: We identified 30 studies, including four reporting clinical effectiveness, 27 immunogenicity, and 12 reporting safety outcomes. PWH were 3% [risk ratio 0.97, 95% confidence interval (95% CI) 0.95-0.99] less likely to seroconvert and 5% less likely to demonstrate neutralization responses (risk ratio 0.95, 95% CI 0.91-0.99) following a primary vaccine schedule. Having a CD4 + T-cell count less than 350 cells/µl (risk ratio 0.91, 95% CI 0.83-0.99) compared with a CD4 + T-cell count more than 350 cells/µl, and receipt of a non-mRNA vaccine in PWH compared with controls (risk ratio 0.86, 95% CI 0.77-0.96) were associated with reduced seroconversion. Two studies reported worse clinical outcomes in PWH. CONCLUSION: Although vaccines appear well tolerated in PWH, this group experience poorer immunological responses following vaccination than controls, particularly with non-mRNA vaccines and low CD4 + T-cell counts. PWH should be prioritized for mRNA COVID-19 vaccines, especially PWH with more advanced immunodeficiency.

Human immunodeficiency virus and solid organ transplantation: a 15-year retrospective audit at a tertiary Australian transplant centre.

BACKGROUND: The incidence of end-stage organ disease in people living with human immunodeficiency virus (HIV) (PLWH) is increasing, as people live longer due to potent, tolerable antiretroviral therapy (ART). Consequently, the number of PLWH who would benefit from solid organ transplant (SOT) is rising. The SOT experience in PLWH in Australia remains limited. Aim To retrospectively review the outcomes for SOT in PLWH at our service, in Victoria, Australia. METHODS: A retrospective cohort study of PLWH undergoing SOT over a 15-year period was performed. Adult PLWH age >18 years were eligible and identified from the Victorian HIV Service database. Descriptive statistics were used to summarise baseline demographics and clinical data, and outcomes following SOT. RESULTS: Nine virologically suppressed PLWH underwent SOT from HIV-negative donors (five kidneys, two livers and two bilateral sequential lung transplants). All patients were male, with a median age of 57.3 years (interquartile range (IQR) = 54.3-60.1) and CD4 count of 485 (IQR = 342-835) at transplantation, and comorbidities were common at baseline. After a median follow up of 3.9 years (IQR = 2.7-7.6), 8 (89%) patents were alive, 7 (78%) had functioning grafts, although 5 (56%) experienced organ rejection. Infections were common. Two patients required modification to their ART due to significant drug-drug interactions prior to transplant, while 5 (56%) had modifications post-SOT. No patients experienced HIV virologic failure. CONCLUSION: PLWH with end-stage organ disease experience good clinical and functional outcomes and should be considered for SOT where indicated. However, multidisciplinary planning and care is essential to optimise care in this patient group.

Skin cancer knowledge, attitudes, and practices among non-medical skin care professionals: A narrative review of cross-sectional and interventional studies.

BACKGROUND: Skin cancers are the most common malignancies in the United States. Total body skin examination by a physician, especially a dermatologist, is the gold standard for detecting suspicious lesions that may require further evaluation. Non-medical professionals (NMPs) including massage therapists, estheticians, hairdressers, and cosmetologists have the unique opportunity to frequently examine their client's skin outside of a clinical setting. By evaluating their knowledge of and comfort with evaluation of suspicious lesions, multiple studies have gauged the utility of patient encounters with NMPs for skin cancer detection. Several studies have also focused on assessment of intervention strategies for assessing and improving NMPs ability to detect suspicious lesions and to refer for physician evaluation when necessary. AIMS: To conduct a narrative review of skin cancer knowledge, attitudes, and practices among NMPs. PATIENTS/METHODS: A systematic search of the databases yielded 16 studies for review. A total of 8 cross-sectional studies examined the knowledge and attitudes of NMPs toward skin evaluation, and 8 studies assessed interventional strategies for improving NMPs' ability to assess skin lesions for consideration of physician referral. RESULTS: This review finds that NMPs are open to the idea of examining the exposed body surfaces relevant to their work with clients and are willing to refer for physician evaluation when needed. Multiple interventional strategies have demonstrated success with educating NMPs on the importance of skin surveillance and the characteristic physical examination findings associated with skin cancers. CONCLUSION: Strengthening the readiness of NMPs to examine their client's skin offers an opportunity to reduce time to skin cancer diagnosis, improve patient outcomes, and lower healthcare-associated costs of skin cancer treatment.

Treatment of invasive IMP-4 Enterobacter cloacae infection in transplant recipients using ceftazidime/avibactam with aztreonam: A case series and literature review.

Infections caused by carbapenemase-producing Enterobacteriaceae (CPE) are an emerging threat in both solid organ and stem cell transplant recipients. Invasive CPE infections in transplant recipients are associated with a high mortality, often due to limited therapeutic options and antibacterial toxicities. One of the most therapeutically challenging group of CPE are the metallo-ß-lactamase (MBL)-producing Gram-negative bacteria, which are now found worldwide, and often need treatment with older, highly toxic antimicrobial regimens. Newer ß-lactamase inhibitors such as avibactam have well-established activity against certain carbapenemases such as Klebsiella pneumoniae carbapenemases (KPC), but have no activity against MBL-producing organisms. Conversely, aztreonam has activity against MBL-producing organisms but is often inactivated by other co-existing ß-lactamases. Here, we report four cases of invasive MBL-CPE infections in transplant recipients caused by IMP-4-producing Enterobacter cloacae who were successfully treated with a new, mechanism-driven antimicrobial combination of ceftazidime/avibactam with aztreonam. This novel antimicrobial combination offers a useful treatment option for high-risk patients with CPE infection, with reduced drug interactions and toxicity.

Improved soybean transformation for efficient and high throughput transgenic production.

Although genetic transformation of soybean dates back to over two decades, the process remains inefficient. Here, we report the development of an organogenesis-based transformation method of soybean that resulted in an average transformation frequency of 18.7%. This improved method resorts to Agrobacterium-mediated transformation of the split-seed explant with an attached partial embryonic axis obtained from an imbibed seed. In addition to the split-seed explant, Agrobacterium strain and preparation were shown to be important for improved transformation. Transformation with Agrobacterium tumefaciens EHA105 generated higher transformation frequencies and number of low copy events compared to the strain EHA101. In this system, phosphinothricin acetyl transferase conferring tolerance to glufosinate was successfully employed for efficiently producing transgenic events. Around 48% of the T1 progeny was demonstrated to be heritable based on molecular analysis and screening with the herbicide Liberty®. This method was shown to be applicable to different genotypes and a few elite lines showed high transformation frequencies. This split-seed system with an attached partial embryonic axis serves not only as an efficient means for high throughput transgenic production for basic research studies but also for the commercial development of transgenic soybean products.