Protocol to study ex vivo T cell priming by conventional dendritic cells from the mouse spleen.

Conventional dendritic cells (cDC) are professional antigen-presenting cells able to prime naive T cells. Here, we present a protocol for ex vivo T cell priming by murine splenic cDC. We describe the steps of injecting fluorescently labeled antigens to mice, purifying antigen-bearing cDC, and priming antigen-specific T cells ex vivo.

Uptake of guideline-based testing for chronic viral hepatitis in Australian primary care: retrospective analysis of electronic medical record data.

Background Diagnosis is essential for engagement in care for chronic hepatitis B (CHB) and chronic hepatitis C (CHC), however, many Australians remain undiagnosed, especially for CHB. Primary care represents an important setting for testing, and this study sought to examine coverage in a large representative cohort of patients. Methods We analysed retrospective data from the electronic medical records of active patients visiting 566 primary care clinics in Victoria, Australia.

Is Respiratory Viral Infection an Inciting Event in the Development of Melioidosis? A Systematic Evaluation of Co-infection With and SARS-CoV-2 or Influenza.

Respiratory viral infection may increase infection with progressing to clinical disease (melioidosis). This data linkage study evaluated associations between melioidosis and SARS-CoV-2 or influenza. Among 160 melioidosis cases, there was no difference in risk factors, vaccine status, or disease severity between 17 with viral co-infection and 143 without.

pseudo-outbreak due to laboratory cross-contamination: A molecular epidemiology outbreak investigation.

Background: Mycobacterial culture is routinely performed to diagnose tuberculosis (TB) in Canada. Globally, meta-analyses suggest that up to 2% of positive cultures are falsely positive for due to laboratory cross-contamination. Five patients from distinct clinical institutions in Montréal were diagnosed with culture-positive TB as their clinical samples were processed in a centralized mycobacteria laboratory.

Polyfunctionality and breadth of HIV-1 antibodies are associated with delayed disease progression.

HIV-1 infection leads to chronic disease requiring life-long treatment and therefore alternative therapeutics, a cure and/or a protective vaccine are needed. Antibody-mediated effector functions could have a role in the fight against HIV-1. However, the properties underlying the potential beneficial effects of antibodies during HIV-1 infection are poorly understood.

A longitudinal study of alcohol consumption among adults in Victoria, Australia during the COVID-19 pandemic.

Objectives: Whilst public health measures were effective in reducing COVID-19 transmission, unintended negative consequences may have occurred. This study aims to assess changes alcohol consumption and the heavy episodic drinking (HED) during the pandemic.

Methods: Data were from the Optimise Study, a longitudinal cohort of Australian adults September 2020-August 2022 that over-sampled priority populations at higher risk of contracting COVID-19, developing severe COVID-19 or experiencing adverse consequences of lockdowns.

Multi-methods process evaluation of the SToP (See, Treat, Prevent) trial: a cluster randomised, stepped wedge trial to support healthy skin.

Background: Healthy skin is important for maintaining overall physical and cultural health and wellbeing. However, remote-living Australian Aboriginal children contend with disproportionally high rates of (Strep A) infected impetigo. The SToP Trial was a large stepped-wedge cluster randomised trial of See, Treat, and Prevent (SToP) skin health activities implemented between 2019 and 2022 in the Kimberley region of Western Australia, during which a decrease in impetigo was observed.

MAIT cell plasticity enables functional adaptation that drives antibacterial immune protection.

Mucosal-associated invariant T (MAIT) cells are known for their rapid effector functions and antibacterial immune protection. Here, we define the plasticity of interferon-γ (IFN-γ)-producing MAIT1 and interleukin-17A (IL-17A)-producing MAIT17 cell subsets in vivo. Whereas T-bet MAIT1 cells remained stable in all experimental settings, after adoptive transfer or acute or infection, RORγt MAIT17 cells could undergo phenotypic and functional conversion into both RORγtT-bet MAIT1/17 and RORγtT-bet MAIT1 cells.

Successful management of a multi-species outbreak of carbapenem-resistant organisms in Fiji: a prospective genomics-enhanced investigation and response.

Background: Fiji is a Pacific Island nation grappling with the increasing threat of antimicrobial resistance (AMR). While genomic technologies are increasingly utilised to understand the emergence and spread of AMR globally, its application to inform outbreak responses in low- and middle-income settings has not been reported.

Methods: Through an established capacity building program, suspected carbapenem-resistant organisms (CRO) identified at Colonial War Memorial Hospital in Fiji (Jan 2022-Oct 2023) underwent whole genome sequencing and analysis.

Global differences and risk factors influencing drug hypersensitivity quality of life: A multicenter, multiethnic study of drug allergy across 3 continents.

Background: Penicillin allergy labels are associated with many adverse outcomes. Fear and restriction of future medication use also have an impact on health-related quality of life (HR-QoL). However, the impact of a drug allergy on HR-QoL and its associated factors remains unknown.

A call to innovate Antarctic avian influenza surveillance.

Highly pathogenic avian influenza (HPAI) viruses are increasingly spreading between birds and mammals globally, with sporadic transmission to humans. With recent emergence in Antarctica, traditional animal capture and influenza testing approaches have proven challenging and logistically impractical. Without reference laboratories in the region, responses are slow and few samples will ever be collected or tested from local outbreaks due to lack of infrastructure.

Identifying gaps in infection prevention and control practice in Australian residential aged care using scenarios.

Background: Older people living in residential aged care are vulnerable to infections. High quality infection prevention and control (IPC) practice is therefore vital in this setting. It is important to assess current IPC practice to identify areas where best practice is lacking, and where improvement efforts could most effectively be targeted.

Characterizing the pharmacological interaction of the antimalarial combination artefenomel-piperaquine in healthy volunteers with induced blood-stage Plasmodium falciparum to predict efficacy in patients with malaria.

Background: The combination antimalarial artefenomel-piperaquine failed to achieve target efficacy in a phase 2b study in Africa and Vietnam. We retrospectively evaluated whether characterizing the pharmacological interaction of this antimalarial combination in a volunteer infection study (VIS) would have enabled prediction of the phase 2b study results.

Methods: Twenty-four healthy adults enrolled over three consecutive cohorts were inoculated with Plasmodium falciparum-infected erythrocytes on day 0.

Effect of a Reduced PCV10 Dose Schedule on Pneumococcal Carriage in Vietnam.

Background: After pneumococcal disease and colonization have been controlled through vaccination campaigns, a reduced pneumococcal conjugate vaccine (PCV) schedule may be sufficient to sustain that control at reduced costs.

Methods: We investigated whether a single primary dose and booster dose (1p+1) of the 10-valent PCV (PCV10) would be noninferior to alternative dose schedules in sustaining control of carriage of pneumococcal serotypes included in the vaccine. In Nha Trang, Vietnam, an area in which PCV had not been used previously, a PCV10 catch-up campaign was conducted in which the vaccine was offered to children younger than 3 years of age, after which a cluster-randomized trial was conducted in which children received PCV10 at 2, 3, and 4 months of age (3p+0 group); at 2, 4, and 12 months of age (2p+1 group); at 2 and 12 months of age (1p+1 group); or at 12 months of age (0p+1 group).

Clinical Snapshot of Group A Streptococcal Isolates from an Australian Tertiary Hospital.

(Group A , GAS) is a human-restricted pathogen that causes a wide range of diseases from pharyngitis and scarlet fever to more severe, invasive infections such as necrotising fasciitis and streptococcal toxic shock syndrome. There has been a global increase in both scarlet fever and invasive infections during the COVID-19 post-pandemic period. The aim of this study was the molecular characterisation of 17 invasive and non-invasive clinical non-1 GAS isolates from an Australian tertiary hospital collected between 2021 and 2022.

Nosocomial Transmission of Necrotizing Fasciitis: A Molecular Characterization of Group A Streptococcal DNases in Clinical Virulence.

, or Group A (GAS), is responsible for over 500,000 deaths per year. Approximately 15% of these deaths are caused by necrotizing soft-tissue infections. In 2008, we isolated an M5 GAS, named the LO1 strain, responsible for the nosocomial transmission of necrotizing fasciitis between a baby and a nurse in Belgium.

MR1 presents vitamin B6-related compounds for recognition by MR1-reactive T cells.

The major histocompatibility complex class I related protein (MR1) presents microbially derived vitamin B2 precursors to mucosal-associated invariant T (MAIT) cells. MR1 can also present other metabolites to activate MR1-restricted T cells expressing more diverse T cell receptors (TCRs), some with anti-tumor reactivity. However, knowledge of the range of the antigen(s) that can activate diverse MR1-reactive T cells remains incomplete.

Changes in isolation guidelines for CPE patients results in only mild reduction in required hospital beds.

Background: Carbapenemase-producing Enterobacterales (CPE) are an emerging public health concern globally as they are resistant to a broad spectrum of antibiotics. Colonisation with CPE typically requires patients to be managed under 'contact precautions', which creates additional physical bed demands in healthcare facilities.

Methods: This study examined the potential impact of revised isolation guidelines introduced in late 2023 in Victoria, Australia, that relaxed the requirement for indefinite isolation of CPE-colonised patients in contact precautions, based on admission of CPE-diagnosed cases prior to the guideline change.

Dual CD47 and PD-L1 blockade elicits anti-tumor immunity by intratumoral CD8 T cells.

Objectives: Bispecific antibodies targeting CD47 and PD-L1 (CD47 × PD-L1 BisAb) demonstrate efficacy against a range of solid cancers. While dual blockade negates anti-CD47-mediated toxicity, the effect of combined innate and adaptive immune activation on protective tumor-resident CD8 T cells has yet to be fully elucidated.

Methods: CD8 T cell populations were tracked upon CD47 × PD-L1 BisAb treatment in an orthotopic model of murine breast cancer where anti-tumor immunity is mediated by CD8 T cells.