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Long COVID occurs in a small but important minority of patients following COVID-19, reducing quality of life and contributing to healthcare burden. Although research into underlying mechanisms is evolving, immunity is understudied. SARS-CoV-2-specific T cell responses are of key importance for viral clearance and COVID-19 recovery. However, in long COVID, the establishment and persistence of SARS-CoV-2-specific T cells are far from clear, especially beyond 12 mo postinfection and postvaccination. We defined ex vivo antigen-specific B cell and T cell responses and their T cell receptors (TCR) repertoires across 2 y postinfection in people with long COVID. Using 13 SARS-CoV-2 peptide-HLA tetramers, spanning 11 HLA allotypes, as well as spike and nucleocapsid probes, we tracked SARS-CoV-2-specific CD8 + and CD4 + T cells and B-cells in individuals from their first SARS-CoV-2 infection through primary vaccination over 24 mo. The frequencies of ORF1a- and nucleocapsid-specific T cells and B cells remained stable over 24 mo. Spike-specific CD8 + and CD4 + T cells and B cells were boosted by SARS-CoV-2 vaccination, indicating immunization, in fully recovered and people with long COVID, altered the immunodominance hierarchy of SARS-CoV-2 T cell epitopes. Meanwhile, influenza-specific CD8 + T cells were stable across 24 mo, suggesting no bystander-activation. Compared to total T cell populations, SARS-CoV-2-specific T cells were enriched for central memory phenotype, although the proportion of central memory T cells decreased following acute illness. Importantly, TCR repertoire composition was maintained throughout long COVID, including postvaccination, to 2 y postinfection. Overall, we defined ex vivo SARS-CoV-2-specific B cells and T cells to understand primary and recall responses, providing key insights into antigen-specific responses in people with long COVID., Competing Interests: Competing interests statement:Hayley McQuilten consults for Ena Respiratory.

Cellular locomotion is required for survival, fertility, proper embryonic development, regeneration, and wound healing. Cell migration is a major component of metastasis, which accounts for two-thirds of all solid tumor deaths. While many studies have demonstrated increased energy requirements, metabolic rates, and migration of cancer cells compared with normal cells, few have systematically compared normal and cancer cell migration as well as energy requirements side by side. Thus, we investigated how non-malignant and malignant cells migrate, utilizing several cell lines from the breast and lung. Initial screening was performed in an unbiased high-throughput manner for the ability to migrate/invade on collagen and/or Matrigel. We unexpectedly observed that all the non-malignant lung cells moved significantly faster than cells derived from lung tumors regardless of the growth media used. Given the paradigm-shifting nature of our discovery, we pursued the mechanisms that could be responsible. Neither mass, cell doubling, nor volume accounted for the individual speed and track length of the normal cells. Non-malignant cells had higher levels of intracellular ATP at premigratory-wound induction stages. Meanwhile, cancer cells also increased intracellular ATP at premigratory-wound induction, but not to the levels of the normal cells, indicating the possibility for further therapeutic investigation.

The Australian Partnership for Preparedness Research on InfectiouS disease Emergencies (APPRISE) has developed a virtual biobank to support infectious disease research in Australia. The virtual biobank (https://apprise.biogrid.org.au) integrates access to existing distributed infectious disease biospecimen collections comprising multiple specimen types, including plasma, serum, and peripheral blood mononuclear cells. Through the development of a common data model, multiple collections can be searched simultaneously via a secure web portal. The portal enhances the visibility and searchability of existing collections within their current governance and custodianship arrangements. The portal is easily scalable for integration of additional collections.

High-risk groups, including Indigenous people, are at risk of severe COVID-19. Here we found that Australian First Nations peoples elicit effective immune responses to COVID-19 BNT162b2 vaccination, including neutralizing antibodies, receptor-binding domain (RBD) antibodies, SARS-CoV-2 spike-specific B cells, and CD4 + and CD8 + T cells. In First Nations participants, RBD IgG antibody titers were correlated with body mass index and negatively correlated with age. Reduced RBD antibodies, spike-specific B cells and follicular helper T cells were found in vaccinated participants with chronic conditions (diabetes, renal disease) and were strongly associated with altered glycosylation of IgG and increased interleukin-18 levels in the plasma. These immune perturbations were also found in non-Indigenous people with comorbidities, indicating that they were related to comorbidities rather than ethnicity. However, our study is of a great importance to First Nations peoples who have disproportionate rates of chronic comorbidities and provides evidence of robust immune responses after COVID-19 vaccination in Indigenous people., (© 2023. The Author(s).)

Pregnancy poses a greater risk for severe COVID-19; however, underlying immunological changes associated with SARS-CoV-2 during pregnancy are poorly understood. We defined immune responses to SARS-CoV-2 in unvaccinated pregnant and nonpregnant women with acute and convalescent COVID-19, quantifying 217 immunological parameters. Humoral responses to SARS-CoV-2 were similar in pregnant and nonpregnant women, although our systems serology approach revealed distinct antibody and FcγR profiles between pregnant and nonpregnant women. Cellular analyses demonstrated marked differences in NK cell and unconventional T cell activation dynamics in pregnant women. Healthy pregnant women displayed preactivated NK cells and γδ T cells when compared with healthy nonpregnant women, which remained unchanged during acute and convalescent COVID-19. Conversely, nonpregnant women had prototypical activation of NK and γδ T cells. Activation of CD4+ and CD8+ T cells and T follicular helper cells was similar in SARS-CoV-2-infected pregnant and nonpregnant women, while antibody-secreting B cells were increased in pregnant women during acute COVID-19. Elevated levels of IL-8, IL-10, and IL-18 were found in pregnant women in their healthy state, and these cytokine levels remained elevated during acute and convalescent COVID-19. Collectively, we demonstrate perturbations in NK cell and γδ T cell activation in unvaccinated pregnant women with COVID-19, which may impact disease progression and severity during pregnancy.

Patients with preexisting metabolic disorders such as diabetes are at a higher risk of developing severe coronavirus disease 2019 (COVID-19). Mitochondrion, the very organelle that controls cellular metabolism, holds the key to understanding disease progression at the cellular level. Our current study aimed to understand how cellular metabolism contributes to COVID-19 outcomes. Metacore pathway enrichment analyses on differentially expressed genes (encoded by both mitochondrial and nuclear deoxyribonucleic acid (DNA)) involved in cellular metabolism, regulation of mitochondrial respiration and organization, and apoptosis, was performed on RNA sequencing (RNASeq) data from blood samples collected from healthy controls and patients with mild/moderate or severe COVID-19. Genes from the enriched pathways were analyzed by network analysis to uncover interactions among them and up- or downstream genes within each pathway. Compared to the mild/moderate COVID-19, the upregulation of a myriad of growth factor and cell cycle signaling pathways, with concomitant downregulation of interferon signaling pathways, were observed in the severe group. Matrix metallopeptidase 9 ( MMP9) was found in five of the top 10 upregulated pathways, indicating its potential as therapeutic target against COVID-19. In summary, our data demonstrates aberrant activation of endocrine signaling in severe COVID-19, and its implication in immune and metabolic dysfunction.

Background: Coronavirus disease 2019 (COVID-19) is an infectious disease caused by severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2). Infected individuals display a wide spectrum of disease severity, as defined by the World Health Organization (WHO). One of the main factors underlying this heterogeneity is the host immune response, with severe COVID-19 often associated with a hyperinflammatory state., Aim: Our current study aimed to pinpoint the specific genes and pathways underlying differences in the disease spectrum and outcomes observed, through in-depth analyses of whole blood transcriptomics in a large cohort of COVID-19 participants., Results: All WHO severity levels were well represented and mild and severe disease displaying distinct gene expression profiles. WHO severity levels 1-4 were grouped as mild disease, and signatures from these participants were different from those with WHO severity levels 6-9 classified as severe disease. Severity level 5 (moderate cases) presented a unique transitional gene signature between severity levels 2-4 (mild/moderate) and 6-9 (severe) and hence might represent the turning point for better or worse disease outcome. Gene expression changes are very distinct when comparing mild/moderate or severe cases to healthy controls. In particular, we demonstrated the hallmark down-regulation of adaptive immune response pathways and activation of neutrophil pathways in severe compared to mild/moderate cases, as well as activation of blood coagulation pathways., Conclusions: Our data revealed discrete gene signatures associated with mild, moderate, and severe COVID-19 identifying valuable candidates for future biomarker discovery., Competing Interests: The authors declare that the research was conducted in the absence of any commercial or financial relationships that could be construed as a potential conflict of interest., (Copyright © 2023 Wang, Schughart, Pelaia, Chew, Kim, Karvunidis, Knippenberg, Teoh, Phu, Short, Iredell, Thevarajan, Audsley, Macdonald, Burcham, McLean, PREDICT-19 consortium, Tang and Shojaei.)

Immunosuppressive tumor microenvironment (TME) impedes anti-tumor immune responses and contributes to immunotherapy resistance in triple-negative breast cancer (TNBC). ADAM12, a member of cell surface metalloproteases, is selectively upregulated in mesenchymal/claudin-low TNBCs, where its expression is largely restricted to tumor cells. The role of cancer cell-expressed ADAM12 in modulating the immune TME is not known. We show that Adam12 knockout in the T11 mouse syngeneic transplantation model of claudin-low TNBC leads to decreased numbers of tumor-infiltrating neutrophils (TINs)/polymorphonuclear myeloid-derived suppressor cells (PMN-MDSCs) and increased numbers of tumor-infiltrating B cells and T cells. ADAM12 loss in cancer cells increases chemotaxis of B cells in vitro and this effect is eliminated by inhibition of CXCR4, a receptor for CXCL12, or anti-CXCL12 blocking antibody. Importantly, ADAM12 loss in T11 cancer cells sensitizes tumors to anti-PD1/anti-CTLA4 combination therapy, although the initial responsiveness is followed by acquired therapy resistance. Depletion of B cells in mice eliminates the improved response to immune checkpoint blockade of Adam12 knockout T11 tumors. Analysis of gene expression data for claudin-low TNBCs from the METABRIC patient cohort shows significant inverse correlations between ADAM12 and gene expression signatures of several anti-tumor immune cell populations, as well as a significant positive correlation between ADAM12 and gene expression signature of TINs/PMN-MDSCs. Collectively, these results implicate ADAM12 in immunosuppression within the TME in TNBC., Competing Interests: The authors declare no conflicts of interest., (© 2022 The Author(s). Published with license by Taylor & Francis Group, LLC.)

Background: Based primarily on in vitro and animal models, with little data directly addressing patient outcomes, current guidelines recommend treating staphylococcal prosthetic valve endocarditis (PVE) with antibiotic combinations including gentamicin and rifampin. Here, we synthesize the clinical data on adjunctive rifampin and gentamicin in staphylococcal PVE., Methods: We conducted a systematic review and meta-analysis of PubMed- and Cochrane-indexed studies reporting outcomes of staphylococcal PVE treated with adjunctive rifampin, gentamicin, both agents, or neither (ie, glycopeptide or β-lactam monotherapy). We recorded outcomes including mortality, relapsed infection, length of stay, nephrotoxicity, hepatotoxicity, and important drug-drug interactions (DDIs)., Results: Four relevant studies were identified. Two studies (n = 117) suggested that adding gentamicin to rifampin-containing regimens did not reduce clinical failure (odds ratio [OR], 0.98 [95% confidence interval {CI}, .39-2.46]), and 2 studies (n = 201) suggested that adding rifampin to gentamicin-containing regimens did not reduce clinical failure (OR, 1.29 [95% CI, .71-2.33]). Neither gentamicin nor rifampin was associated with reduced infection relapse; 1 study found that rifampin treatment was associated with longer hospitalizations (mean, 31.3 vs 42.3 days; P < .001). Comparative safety outcomes were rarely reported, but 1 study found rifampin to be associated with hepatoxicity, nephrotoxicity, and DDIs, leading to treatment discontinuation in 31% of patients., Conclusions: The existing clinical data do not suggest a benefit of either adjunctive gentamicin or rifampin in staphylococcal PVE. Given that other studies also suggest these agents add nephrotoxicity, hepatoxicity, and risk of DDIs without benefit in staphylococcal endovascular infections, we suggest that recommendations for gentamicin and rifampin in PVE be downgraded and primarily be used within the context of clinical trials., Competing Interests: Potential conflicts of interest. The authors: No reported conflicts of interest., (© The Author(s) 2022. Published by Oxford University Press on behalf of Infectious Diseases Society of America.)

Background: Regular repeat surveillance testing is a strategy to identify asymptomatic individuals with SARS-CoV-2 infections in high-risk work settings to prevent onward community transmission. Saliva sampling is less invasive compared to nasal/oropharyngeal sampling, thus making it suitable for regular testing. In this multi-centre evaluation, we aimed to validate RT-PCR using salivary swab testing of SARS-CoV-2 for large-scale surveillance testing and assess implementation amongst staff working in the hotel quarantine system in Victoria, Australia., Methods: A multi-centre laboratory evaluation study was conducted to systematically validate the in vitro and clinical performance of salivary swab RT-PCR for implementation of SARS-CoV-2 surveillance testing. Analytical sensitivity for multiple RT-PCR platforms was assessed using a dilution series of known SARS-CoV-2 viral loads, and assay specificity was examined using a panel of viral pathogens other than SARS-CoV-2. In addition, we tested capacity for large-scale saliva testing using a four-sample pooling approach, where positive pools were subsequently decoupled and retested. Regular, frequent self-collected saliva swab RT-PCR testing was implemented for staff across fourteen quarantine hotels. Samples were tested at three diagnostic laboratories validated in this study, and results were provided back to staff in real-time., Findings: The agreement of self-collected saliva swabs for RT-PCR was 84.5% (95% CI 68.6 to 93.8) compared to RT-PCR using nasal/oropharyngeal swab samples collected by a healthcare practitioner, when saliva samples were collected within seven days of symptom onset. Between 7th December 2020 and 17th December 2021, almost 500,000 RT-PCR tests were performed on saliva swabs self-collected by 102 staff working in quarantine hotels in Melbourne. Of these, 20 positive saliva swabs were produced by 13 staff (0.004%). The majority of staff that tested positive occurred during periods of community transmission of the SARS-CoV-2 Delta variant., Interpretation: Salivary RT-PCR had an acceptable level of agreement compared to standard nasal/oropharyngeal swab RT-PCR within early symptom onset. The scalability, tolerability and ease of self-collection highlights utility for frequent or repeated testing in high-risk settings, such as quarantine or healthcare environments where regular monitoring of staff is critical for public health, and protection of vulnerable populations., Funding: This work was funded by the Victorian Department of Health., Competing Interests: All authors declare no competing interests., (© 2022 The Author(s).)

Respiratory tract infection with SARS-CoV-2 results in varying immunopathology underlying COVID-19. We examine cellular, humoral and cytokine responses covering 382 immune components in longitudinal blood and respiratory samples from hospitalized COVID-19 patients. SARS-CoV-2-specific IgM, IgG, IgA are detected in respiratory tract and blood, however, receptor-binding domain (RBD)-specific IgM and IgG seroconversion is enhanced in respiratory specimens. SARS-CoV-2 neutralization activity in respiratory samples correlates with RBD-specific IgM and IgG levels. Cytokines/chemokines vary between respiratory samples and plasma, indicating that inflammation should be assessed in respiratory specimens to understand immunopathology. IFN-α2 and IL-12p70 in endotracheal aspirate and neutralization in sputum negatively correlate with duration of hospital stay. Diverse immune subsets are detected in respiratory samples, dominated by neutrophils. Importantly, dexamethasone treatment does not affect humoral responses in blood of COVID-19 patients. Our study unveils differential immune responses between respiratory samples and blood, and shows how drug therapy affects immune responses during COVID-19., (© 2022. The Author(s).)

SKD3, also known as human CLPB, belongs to the AAA+ family of ATPases associated with various activities. Mutations in the SKD3/CLPB gene cause 3-methylglutaconic aciduria type VII and congenital neutropenia. SKD3 is upregulated in acute myeloid leukemia, where it contributes to anti-cancer drug resistance. SKD3 resides in the mitochondrial intermembrane space, where it forms ATP-dependent high-molecular weight complexes, but its biological function and mechanistic links to the clinical phenotypes are currently unknown. Using sedimentation equilibrium and dynamic light scattering, we show that SKD3 is monomeric at low protein concentration in the absence of nucleotides, but it forms oligomers at higher protein concentration or in the presence of adenine nucleotides. The apparent molecular weight of the nucleotide-bound SKD3 is consistent with self-association of 12 monomers. Image-class analysis and averaging from negative-stain electron microscopy (EM) of SKD3 in the ATP-bound state visualized cylinder-shaped particles with an open central channel along the cylinder axis. The dimensions of the EM-visualized particle suggest that the SKD3 dodecamer is formed by association of two hexameric rings. While hexameric structure has been often observed among AAA+ ATPases, a double-hexamer sandwich found for SKD3 appears uncommon within this protein family. A functional significance of the non-canonical structure of SKD3 remains to be determined., Competing Interests: Declaration of competing interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2022 Elsevier Inc. All rights reserved.)

Background: The coronavirus disease 2019 (COVID-19) pandemic has had a profound and prolonged impact on healthcare services and healthcare workers., Aims: The Australian COVID-19 Frontline Healthcare Workers Study aimed to investigate the severity and prevalence of mental health issues, as well as the social, workplace and financial disruptions experienced by Australian healthcare workers during the COVID-19 pandemic., Methods: A nationwide, voluntary, anonymous, single timepoint, online survey was conducted between 27 August and 23 October 2020. Individuals self-identifying as frontline healthcare workers in secondary or primary care were invited to participate. Participants were recruited through health organisations, professional associations or colleges, universities, government contacts and national media. Demographics, home and work situation, health and psychological well-being data were collected., Results: A total of 9518 survey responses were received; of the 9518 participants, 7846 (82.4%) participants reported complete data. With regard to age, 4110 (52.4%) participants were younger than 40 years; 6344 (80.9%) participants were women. Participants were nurses (n=3088, 39.4%), doctors (n=2436, 31.1%), allied health staff (n=1314, 16.7%) or in other roles (n=523, 6.7%). In addition, 1250 (15.9%) participants worked in primary care. Objectively measured mental health symptoms were common: mild to severe anxiety (n=4694, 59.8%), moderate to severe burnout (n=5458, 70.9%) and mild to severe depression (n=4495, 57.3%). Participants were highly resilient (mean (SD)=3.2 (0.66)). Predictors for worse outcomes on all scales included female gender; younger age; pre-existing psychiatric condition; experiencing relationship problems; nursing, allied health or other roles; frontline area; being worried about being blamed by colleagues and working with patients with COVID-19., Conclusions: The COVID-19 pandemic is associated with significant mental health symptoms in frontline healthcare workers. Crisis preparedness together with policies and practices addressing psychological well-being are needed., Competing Interests: Competing interests: None declared., (© Author(s) (or their employer(s)) 2021. Re-use permitted under CC BY-NC. No commercial re-use. See rights and permissions. Published by BMJ.)

Objectives: The Australian COVID-19 Frontline Healthcare Workers Study investigated coping strategies and help-seeking behaviours, and their relationship to mental health symptoms experienced by Australian healthcare workers (HCWs) during the COVID-19 pandemic., Methods: Australian HCWs were invited to participate a nationwide, voluntary, anonymous, single time-point, online survey between 27th August and 23rd October 2020. Complete responses on demographics, home and work situation, and measures of health and psychological wellbeing were received from 7846 participants., Results: The most commonly reported adaptive coping strategies were maintaining exercise (44.9%) and social connections (31.7%). Over a quarter of HCWs (26.3%) reported increased alcohol use which was associated with a history of poor mental health and worse personal relationships. Few used psychological wellbeing apps or sought professional help; those who did were more likely to be suffering from moderate to severe symptoms of mental illness. People living in Victoria, in regional areas, and those with children at home were significantly less likely to report adaptive coping strategies., Conclusions: Personal, social, and workplace predictors of coping strategies and help-seeking behaviour during the pandemic were identified. Use of maladaptive coping strategies and low rates of professional help-seeking indicate an urgent need to understand the effectiveness of, and the barriers and enablers of accessing, different coping strategies., (Copyright © 2021 Elsevier Inc. All rights reserved.)

Intrinsically disordered proteins (IDPs) are key components of regulatory networks that control crucial aspects of cell decision making. The intrinsically disordered transactivation domain (TAD) of tumor suppressor p53 mediates its interactions with multiple regulatory pathways to control the p53 homeostasis during the cellular response to genotoxic stress. Many cancer-associated mutations have been discovered in p53-TAD, but their structural and functional consequences are poorly understood. Here, by combining atomistic simulations, NMR spectroscopy, and binding assays, we demonstrate that cancer-associated mutations can significantly perturb the balance of p53 interactions with key activation and degradation regulators. Importantly, the four mutations studied in this work do not all directly disrupt the known interaction interfaces. Instead, at least three of these mutations likely modulate the disordered state of p53-TAD to perturb its interactions with regulators. Specifically, NMR and simulation analysis together suggest that these mutations can modulate the level of conformational expansion as well as rigidity of the disordered state. Our work suggests that the disordered conformational ensemble of p53-TAD can serve as a central conduit in regulating the response to various cellular stimuli at the protein-protein interaction level. Understanding how the disordered state of IDPs may be modulated by regulatory signals and/or disease associated perturbations will be essential in the studies on the role of IDPs in biology and diseases., Competing Interests: Declaration of Competing Interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2021 Elsevier Ltd. All rights reserved.)

Background: Adequate preparation and support for healthcare workers (HCWs) managing high-consequence infectious diseases (HCIDs) is critical to the overall clinical management of HCIDs. Qualitative studies examining how well prepared and supported HCWs feel are lacking despite their key role. This study investigated how prepared and supported front-line HCWs at an Australian tertiary hospital felt about managing HCIDs such as viral haemorrhagic fever (VHF)., Methods: A qualitative research approach was used to undertake interviews with 45 Royal Melbourne Hospital medical and nursing staff from emergency, intensive care and infectious diseases. Interview questions captured data on HCWs' role, familiarity with using protocols, psychological attributes and training for scenarios related to VHF patient management. Interviews were recorded and transcribed. Categorical responses were analysed quantitatively and open-ended responses were analysed thematically., Results: Ninety-eight percent of participants indicated feeling capable of undertaking their role in managing VHF patients; 77% felt supported through personnel/resources. However, 69% indicated barriers to managing these patients effectively; and 68% felt anxious at the prospect of managing VHF patients. Themes emerging from participants' observations included concerns about training frequency, miscommunication, difficulty with uncertainty, feeling underprepared, and fear of transmitting infection to others., Conclusion: Although the majority of HCWs feel confident about their ability to care for VHF patients, they also have a moderately-high degree of anxiety. Perceptions of interviewed staff have fed into recommendations to increase HCW preparedness and reduce anxiety, which include investigating support services, and exploring training options that create multi-departmental groups of highly specialised medical officers and nurses., (Crown Copyright © 2020. Published by Elsevier B.V. All rights reserved.)

SARS-CoV-2 causes a spectrum of COVID-19 disease, the immunological basis of which remains ill defined. We analyzed 85 SARS-CoV-2-infected individuals at acute and/or convalescent time points, up to 102 days after symptom onset, quantifying 184 immunological parameters. Acute COVID-19 presented with high levels of IL-6, IL-18, and IL-10 and broad activation marked by the upregulation of CD38 on innate and adaptive lymphocytes and myeloid cells. Importantly, activated CXCR3 + cT FH 1 cells in acute COVID-19 significantly correlate with and predict antibody levels and their avidity at convalescence as well as acute neutralization activity. Strikingly, intensive care unit (ICU) patients with severe COVID-19 display higher levels of soluble IL-6, IL-6R, and IL-18, and hyperactivation of innate, adaptive, and myeloid compartments than patients with moderate disease. Our analyses provide a comprehensive map of longitudinal immunological responses in COVID-19 patients and integrate key cellular pathways of complex immune networks underpinning severe COVID-19, providing important insights into potential biomarkers and immunotherapies., Competing Interests: The authors declare no competing interests., (© 2021 The Author(s).)

Human caseinolytic peptidase B protein homolog (CLPB), also known as suppressor of potassium transport defect 3 (SKD3), is a broadly-expressed member of the family of ATPases associated with diverse cellular activities (AAA+). Mutations in the human CLPB gene cause 3-methylglutaconic aciduria type VII. CLPB is upregulated in acute myeloid leukemia (AML), where it contributes to anti-cancer drug resistance. The biological function of CLPB in human cells and mechanistic links to the clinical phenotypes are currently unknown. Herein, subcellular fractionation of human HEK-293 and BT-549 cells showed that a single 57-kDa form of CLPB was present in the mitochondria and not in the cytosolic fraction. Immunofluorescence staining of HEK-293 and BT-549 cells with anti-CLPB antibody co-localized with the mitochondrial staining using a MitoTracker dye. In purified intact mitochondria, CLPB was protected against externally added proteinase K, but it was susceptible to degradation after disruption of the outer membrane, indicating that CLPB resides in the mitochondrial intermembrane space. Overexpressed CLPB, while properly trafficked to the mitochondria, appeared to form large clusters/aggregates that were resistant to extraction with non-ionic detergents and were readily visualized by immunofluorescence microscopy. Importantly, endogenous CLPB formed high molecular weight protein complexes in an ATP-dependent manner that were detected by blue native polyacrylamide gel electrophoresis. These results demonstrate that ATP induces a structural change in CLPB and controls its ability to self-associate or form complexes with other proteins in the intermembrane space of mitochondria., (Copyright © 2020 Elsevier Ltd. All rights reserved.)

The rapid spread of severe acute respiratory syndrome coronavirus 2 led to the declaration of a global pandemic within 3 months of its emergence. The majority of patients presenting with coronavirus disease 2019 (COVID-19) experience a mild illness that can usually be managed in the community. Patients require careful monitoring and early referral to hospital if any signs of clinical deterioration occur. Increased age and the presence of comorbidities are associated with more severe disease and poorer outcomes. Treatment for COVID-19 is currently predominantly supportive care, focused on appropriate management of respiratory dysfunction. Clinical evidence is emerging for some specific therapies (including antiviral and immune-modulating agents). Investigational therapies for COVID-19 should be used in the context of approved randomised controlled trials. Australian clinicians need to be able to recognise, diagnose, manage and appropriately refer patients affected by COVID-19, with thousands of cases likely to present over the coming years., (© 2020 The Authors. Medical Journal of Australia published by John Wiley & Sons Australia, Ltd on behalf of AMPCo Pty Ltd.)

The objective of this investigation was to assess whether between-hospital variation in echocardiography usage for patients with Staphylococcus aureus bacteraemia (SAB) is explained by differences in patients' pre-test probability of endocarditis. This was a retrospective cohort study at three neighbouring hospitals in Australia. Consecutive episodes of SAB were reviewed for the presence of three endocarditis risk factors (community onset, prolonged bacteraemia and the presence of an intracardiac prosthetic device) and the performance and results of all echocardiography studies within 30 days. Multivariate logistic regression was used to examine the effect of hospital site on the performance of (i) transoesophageal and (ii) transthoracic echocardiography controlling for major endocarditis risk factors. Significant variation in echocardiography usage was demonstrated between sites in a total cohort of 1167 episodes of SAB. None of the three sites were found to exhibit echocardiography usage that could be considered consistent with current guidelines, and each differed from the guidelines in different ways. Hospital site, rather than endocarditis risk factors, was the strongest predictor of transthoracic echocardiography use; however, the use of transoesophageal echocardiography was strongly predicted by endocarditis risk factors. Variation in echocardiography use between these hospitals is not adequately explained by differences in the risk factor profile of their SAB cohorts.

Dengue notifications have increased dramatically over the past seven years in Victoria, Australia-a trend which has been seen nationally and reflects increased cases internationally. We reviewed the epidemiology of dengue among Victorian travellers, changes in diagnostic methods and describe the burden placed on local health systems resulting from this disease of public health importance. Cases of dengue notified to the Department of Health and Human Services in Victoria, Australia, between 1 January 2010 and 31 December 2016 were included in this review. Demographic, clinical, diagnostic methods, and risk factor data were examined using descriptive epidemiological analyses. Cases of dengue increased on average by 22% per year, with a total of 2187 cases (5.5 cases/100,000 population) notified over the 7-year reporting period. The most frequently reported country of acquisition was Indonesia (45%) followed by Thailand (14%). The use of multiple diagnostic methods, including the non-structural protein 1 antigen (NS1Ag) detection test, increased over time. The median time between onset of illness and diagnosis diminished from 9 days (IQR: 2⁻15) in 2010 to 4 days (IQR: 2⁻7) in 2016. Proportionally more cases were discharged directly from emergency departments in recent years (10% in 2010 to 28% in 2016, p < 0.001).The increasing incidence of dengue in Australia is reflective of its growing prominence as a travel medicine problem in western countries. For travellers with non-severe dengue, the improved timeliness of dengue diagnostics allows for consideration of best practice ambulatory management approaches as used in endemic areas., Competing Interests: The authors declare no conflict of interest.

We describe a fatal case of Japanese encephalitis virus infection following short-term travel to Thailand. Viral RNA was detected in urine and whole blood out to 26 and 28 days, respectively, after the onset of symptoms. Live virus was isolated from a urine specimen from day 14.

Background: Routine deflation of the endotracheal tube (ETT) cuff of critically ill patients receiving MV is common in Australia and New Zealand. Literature about ventilatorassociated pneumonia (VAP) and antibiotic use rates with different ETT cuff maintenance practices is lacking., Objective: To determine the impact of a change in ETT cuff maintenance from a minimal leak technique to pressure manometry on the administration of antibiotics for VAP., Design, Setting and Participants: A prospective, pre- post observational study conducted in a metropolitan tertiary referral intensive care unit. We analysed data from 178 patients receiving MV for > 48 hours during 13 weeks of minimal leak test ETT cuff technique (pre-intervention, n = 92) or 13 weeks of cuff pressure manometry (postintervention, n = 86), separated by 3 weeks' "wash-out"., Main Outcome Measures: Primary outcome was the number of patients receiving antibiotics for the indication of VAP. Secondary outcomes were incidence of ventilatorassociated surveillance events, lengths of stay (LOSs) and mortality., Results: Antibiotics were administered for VAP in 24 patients (26.1%) in the pre-intervention period compared with 11 post-intervention patients (12.8%). The univariate antibiotic administraion rate per 100 ventilation days was 15.3% (95% CI, 12.6%-18.4%) v 6.8% (95% CI, 4.9%- 9.3%), and the incident rate ratio (IRR) was 0.45 (95% CI, 0.31-0.64); P < 0.001). After adjustment for ventilation duration, IRR was 0.55 (95% CI, 0.24-1.27); P = 0.160. The ventilator-associated complication incidence rate was lower in the post-intervention group (11.4% v 16.3%; IRR, 0.70 [95% CI, 0.51-0.95]; P = 0.018). After adjustment for duration of MV, IRR was 0.66 (95% CI, 0.25-1.70); P = 0.387. Antibiotic administration for VAP was associated with increased ICU and hospital LOSs, but not with mortality., Conclusions: ETT cuff pressure manometry is associated with a reduced rate of antibiotic administration for a diagnosis of VAP compared with a minimal leak test technique.

Objectives: To describe the epidemiology, clinical and laboratory features and outcomes of dengue in returned Australian travellers, applying the revised WHO dengue classification (2009) to this population., Design, Setting and Participants: Retrospective case series analysis of confirmed dengue cases hospitalised at one of four Australian tertiary hospitals, January 2012 - May 2015., Main Outcome Measures: Clinical features, laboratory findings and outcomes of patients with dengue; dengue classification according to 2009 WHO guidelines., Results: 208 hospitalised patients (median age, 32 years; range, 4-76 years) were included in the study. Dengue was most frequently acquired in Indonesia (94 patients, 45%) and Thailand (40, 19%). The most common clinical features were fever (98% of patients) and headache (76%). 84 patients (40%) met the WHO criteria for dengue with warning signs, and one the criteria for severe dengue; the most common warning signs were mucosal bleeding (44 patients, 21%) and abdominal pain (43, 21%). Leukopenia (176 patients, 85%), thrombocytopenia (133, 64%), and elevated liver enzyme levels (154, 76%) were the most common laboratory findings. 46 patients (22%) had serological evidence of previous exposure to dengue virus. WHO guidelines were documented as a management benchmark in ten cases (5%); 46 patients (22%) received non-steroidal anti-inflammatory drugs (NSAIDs)., Conclusions: A significant proportion of returning Australian travellers hospitalised for dengue have unrecognised warning signs of severe disease. Many received NSAIDs, which can increase the risk of haemorrhage in dengue. As travel to Asia from Australia continues to increase, it is vital for averting serious outcomes that clinicians can recognise and manage dengue.

Background: Although the last 10 years have seen a slow decline in global tuberculosis (TB) incidence, it remains one of the most significant infectious diseases worldwide, with an estimated 9.6 million new cases and 1.5 million deaths in 2014. The consequences of contracting TB can be significant for the individual, with extended treatment requirements, risk of long-term health consequences and the possibility of transmitting infection to others among the complications of disease., Methods: This review article discusses the risk of TB infection as a result of international travel including evaluation of risk, risk reduction and a proposed testing strategy for travel-related TB infection. A review of the relevant literature combined with expert opinion was used to formulate this article., Results: The global TB epidemic is varied and dynamic, including changing patterns of both drug sensitive and drug resistant disease. The annual incidence of TB in individual countries such as South Africa may be greater than 800/100,000, while multidrug resistance is found in up to 19% of new cases in the Russian Federation. Recent surveys of traveller risk are presented for short and long-term travellers to various countries and settings. Overall, risk to travelers is low, with rates of acquiring latent TB less than 1% per travel year for most settings. However, detailed travel evaluation is necessary to evaluate individual risk. Travellers with immunosuppressive conditions are at high risk for progression to active disease if infected, and should have special consideration in travel consultation., Discussion: It is important for practitioners giving advice regarding tuberculosis risk and travel to access up-to-date information regarding local conditions. This article provides an approach to assessment and management of TB in travellers, including a guide to pre- and post-travel evaluation, testing and vaccination., (© International Society of Travel Medicine, 2016. All rights reserved. Published by Oxford University Press. For permissions, please e-mail: journals.permissions@oup.com.)