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Burkholderia pseudomallei is the causative agent of melioidosis, a disease highly endemic to Southeast Asia and northern Australia, though the area of endemicity is expanding. Cases may occur in returning travelers or, rarely, from imported contaminated products. Identification of B. pseudomallei is challenging for laboratories that do not see this organism frequently, and misidentifications by matrix-assisted laser desorption/ionization time of flight mass spectrometry (MALDI-TOF MS) and automated biochemical testing have been reported. The in vitro diagnostic database for use with the Vitek MS has recently been updated to include B. pseudomallei and we aimed to validate the performance for identification in comparison to automated biochemical testing with the Vitek 2 GN card, quantitative real-time polymerase chain reaction (qPCR) targeting the type III secretion system, and capsular polysaccharide antigen detection using a lateral flow immunoassay (LFA). We tested a "derivation" cohort including geographically diverse B. pseudomallei and a range of closely related Burkholderia species, and a prospective "validation" cohort of B. pseudomallei and B. cepacia complex clinical isolates. MALDI-TOF MS had a sensitivity of 1.0 and specificity of 1.0 for the identification and differentiation of B. pseudomallei from related Burkholderia species when a certainty cutoff of 99.9% was used. In contrast, automated biochemical testing for B. pseudomallei identification had a sensitivity of 0.83 and specificity of 0.88. Both qPCR and LFA correctly identified all B. pseudomallei isolates with no false positives. Due to the high level of accuracy, we have now incorporated MALDI-TOF MS into our laboratory's B. pseudomallei identification workflow.IMPORTANCE Burkholderia pseudomallei causes melioidosis, a disease associated with high morbidity and mortality that disproportionately affects rural areas in Southeast Asia and northern Australia. The known area of endemicity is expanding and now includes the continental United States. Laboratory identification can be challenging which may result in missed or delayed diagnoses and poor patient outcomes. In this study, we compared mass spectrometry using an updated spectral database with multiple other methods for B. pseudomallei identification and found mass spectrometry highly accurate. We have therefore incorporated this fast and cost-effective method into our laboratory's workflow for B. pseudomallei identification.

Melioidosis is an emerging tropical infectious disease with a rising global burden caused by the environmental bacterium Burkholderia pseudomallei. It is endemic in Southeast and South Asia, including Bangladesh. A rare aminoglycoside-susceptible B. pseudomallei isolate (Y2019) has recently been reported from a melioidosis patient in Dhaka, Bangladesh. To understand the geographical origins of Y2019, we subjected it and 10 other isolates from Bangladesh to whole-genome sequencing. In a phylogenetic tree with a global set of B. pseudomallei genomes, most Bangladeshi genomes clustered tightly within the Asian clade. In contrast, Y2019 was closely related to ST881 isolates from Sarawak, Malaysian Borneo, a gentamicin-sensitive sequence type, suggesting infection in Borneo. Y2019 also contained the same gentamicin sensitivity conferring nonsynonymous mutation in the drug efflux pump encoding the amrB gene. In the absence of a full travel history, whole-genome sequencing and bioinformatics tools have revealed the likely origin of this rare isolate.

Hemodialysis is a risk factor for Staphylococcus aureus bloodstream infection (SAB). In this single-center study, SAB rates were 56% lower during the monsoonal wet season when patients on hemodialysis receive supervised melioidosis prophylaxis with trimethoprim-sulfamethoxazole. This intervention may reduce SAB rates in high-risk patients; however, further targeted studies are required., Competing Interests: Potential conflicts of interest. All authors: No reported conflicts., (© The Author(s) 2024. Published by Oxford University Press on behalf of Infectious Diseases Society of America.)

Genomic diversity in a pathogen population is the foundation for evolution and adaptations in virulence, drug resistance, pathogenesis, and immune evasion. Characterizing, analyzing, and understanding population-level diversity is also essential for epidemiological and forensic tracking of sources and revealing detailed pathways of transmission and spread. For bacteria, culturing, isolating, and sequencing the large number of individual colonies required to adequately sample diversity can be prohibitively time-consuming and expensive. While sequencing directly from a mixed population will show variants among reads, they cannot be linked to reveal allele combinations associated with particular traits or phylogenetic inheritance patterns. Here, we describe the theory and method of how population sequencing directly from a mixed sample can be used in conjunction with sequencing a very small number of colonies to describe the phylogenetic diversity of a population without haplotype reconstruction. To demonstrate the utility of population sequencing in capturing phylogenetic diversity, we compared isogenic clones to population sequences of Burkholderia pseudomallei from the sputum of a single patient. We also analyzed population sequences of Staphylococcus aureus derived from different people and different body sites. Sequencing results confirm our ability to capture and characterize phylogenetic diversity in our samples. Our analyses of B. pseudomallei populations led to the surprising discovery that the pathogen population is highly structured in sputum, suggesting that for some pathogens, sputum sampling may preserve structuring in the lungs and thus present a non-invasive alternative to understanding colonization, movement, and pathogen/host interactions. Our analyses of S. aureus samples show how comparing phylogenetic diversity across populations can reveal directionality of transmission between hosts and across body sites, demonstrating the power and utility for characterizing the spread of disease and identification of reservoirs at the finest levels. We anticipate that population sequencing and analysis can be broadly applied to accelerate research in a broad range of fields reliant on a foundational understanding of population diversity.

Background: Water-associated bacterial infections cause a wide spectrum of disease. Although many of these infections are typically due to human host commensal Staphylococcal or Streptococcal spp, water exposure can result in infections with environmental gram negatives such as Vibrio spp, Aeromonas spp, Chromobacterium violaceum , and Shewanella spp (collectively VACS)., Methods: We performed a retrospective analysis of the epidemiology, clinical presentation, and outcomes of deep and superficial infections associated with VACS organisms in our health service between 1 January 2015 and 31 December 2023., Results: We identified 317 patient episodes of infection with VACS organisms over this period. Of these, Aeromonas spp (63%) was the most common, followed by Vibrio spp (19%), Shewanella spp (13%), and C violaceum (5%). The majority were isolated from males (74.4%) and involved the lower limb (67.5%). Mild infections were more common than severe presentations, with only 15 (4.7%) admissions to the intensive care unit and 8 (2.5%) deaths. Colonization occurred in 6.9% of patients, in contrast to the perceived severity of some of these bacteria. Copathogens were common and included Staphylococcus aureus (48%) and enteric bacteria (57%). The majority of patients (60%) had no documented water exposure. Initial empiric antimicrobial therapy presumptively covered the susceptibilities of the isolated organisms in 47.3% of patients; however, a lack of VACS-covering empirical therapy was not associated with readmission., Conclusions: The isolation of a VACS organism in our setting was often not associated with documented water exposure, which has implications for empiric antimicrobial therapy. Severe disease and death were uncommon., Competing Interests: Potential conflicts of interest. All authors: No reported conflicts., (© The Author(s) 2024. Published by Oxford University Press on behalf of Infectious Diseases Society of America.)

Objectives: Crusted scabies (CS, Norwegian scabies) is a severe form of scabies, characterized by hyper-infestation of Sarcoptes scabiei mites. CS is commonly associated with immunosuppression but is also reported in overtly immunocompetent individuals. We reviewed immunosuppressive risk factors and comorbidities associated with CS., Methods: The National Library of Medicine (PubMed) database was reviewed for patient case reports of CS from January 1998 to July 2023. Two authors screened records for eligibility, extracted data, and one critically appraised the quality of the studies., Systematic Review Registration: PROSPERO CRD42023466126., Results: A total of 436 records were identified, of which 204 were included for systematic review. From these, 683 CS patients were included. CS impacted both genders equally. Adults (21-59 years) were more commonly affected (45.5%) compared to children (0-20 years, 21%). Corticosteroid use was the most prevalent immunosuppressive risk factor identified (27.7% of all cases). About 10.2% of reports were associated with HIV/AIDS, and 8.5% with HTLV-1 infection. 10.5% of patients were overtly immunocompetent with no known risk factors. Overall, 41 (6.0%) died, many subsequent to secondary bacteremia., Conclusion: This study represents the first systematic review undertaken on immunosuppressive risk factors associated with CS. This provides insights into trends of immunosuppression and mechanisms of CS development., Competing Interests: Declarations of competing interests 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 © 2024 The Authors. Published by Elsevier Ltd.. All rights reserved.)

Burkholderia pseudomallei, the causative agent of melioidosis has long been considered able to exist in a latent form. Seropositivity among U.S. soldiers returning from the Vietnam conflict led to melioidosis being dubbed "the Vietnamese time bomb." Cases assigned to "(re)activation from latency" over 30 years of the Darwin Prospective Melioidosis Study (DPMS) were reviewed and reassessed and additional cases from DPMS years 31-34 were added. Historical reports of melioidosis attributed to activation from latency were reviewed. Some earlier DPMS cases and most historical cases described as activation from latency more accurately reflect undiagnosed chronic melioidosis, often with relapsing-remitting courses, rather than truly latent, asymptomatic infection. Such protracted disease should now be diagnosable much earlier, provided melioidosis is considered and laboratory facilities are available. The longest plausible duration of asymptomatic latency remains 29 years. In conclusion, activation from latency is a rare event in melioidosis, accounting in our analysis for under 3% of DPMS cases, consistent with why the Vietnamese time bomb never eventuated.

Melioidosis is a bacterial infection caused by Burkholderia pseudomallei, that is common in tropical and subtropical countries including Southeast Asia and Northern Australia. The magnitude of undiagnosed and untreated melioidosis across the country remains unclear. Given its proximity to regions with high infection rates, Riau Province on Sumatera Island is anticipated to have endemic melioidosis. This study reports retrospectively collected data on 68 culture-confirmed melioidosis cases from two hospitals in Riau Province between January 1, 2009, and December 31, 2021, with full clinical data available on 41 cases. We also describe whole genome sequencing and genotypic analysis of six isolates of B. pseudomallei. The mean age of the melioidosis patients was 49.1 (SD 11.5) years, 85% were male and the most common risk factor was diabetes mellitus (78%). Pulmonary infection was the most common presentation (39%), and overall mortality was 41%. Lung as a focal infection (aOR: 6.43; 95% CI: 1.13-36.59, p = 0.036) and bacteremia (aOR: 15.21; 95% CI: 2.59-89.31, p = 0.003) were significantly associated with death. Multilocus sequence typing analysis conducted on six B.pseudomallei genomes identified three sequence types (STs), namely novel ST1794 (n = 3), ST46 (n = 2), and ST289 (n = 1). A phylogenetic tree of Riau B. pseudomallei whole genome sequences with a global dataset of genomes clearly distinguished the genomes of B. pseudomallei in Indonesia from the ancestral Australian clade and classified them within the Asian clade. This study expands the known presence of B. pseudomallei within Indonesia and confirms that Indonesian B. pseudomallei are genetically linked to those in the rest of Southeast Asia. It is anticipated that melioidosis will be found in other locations across Indonesia as laboratory capacities improve and standardized protocols for detecting and confirming suspected cases of melioidosis are more widely implemented., Competing Interests: The authors have declared that no competing interests exist., (Copyright: © 2024 Anggraini et al. This is an open access article distributed under the terms of the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original author and source are credited.)

Streptococcus dysgalactiae subspecies equisimilis (SDSE) and Streptococcus pyogenes share skin and throat niches with extensive genomic homology and horizontal gene transfer (HGT) possibly underlying shared disease phenotypes. It is unknown if cross-species transmission interaction occurs. Here, we conduct a genomic analysis of a longitudinal household survey in remote Australian First Nations communities for patterns of cross-species transmission interaction and HGT. Collected from 4547 person-consultations, we analyse 294 SDSE and 315 S. pyogenes genomes. We find SDSE and S. pyogenes transmission intersects extensively among households and show that patterns of co-occurrence and transmission links are consistent with independent transmission without inter-species interference. We identify at least one of three near-identical cross-species mobile genetic elements (MGEs) carrying antimicrobial resistance or streptodornase virulence genes in 55 (19%) SDSE and 23 (7%) S. pyogenes isolates. These findings demonstrate co-circulation of both pathogens and HGT in communities with a high burden of streptococcal disease, supporting a need to integrate SDSE and S. pyogenes surveillance and control efforts., (© 2024. The Author(s).)

Melioidosis is a potentially life-threatening infection. This study aimed to assess the melioidosis knowledge among distinct participant groups in the tropical Top End of the Northern Territory (NT) of Australia. Participants were categorised into three groups: NT medical students and health research staff (Group 1: Hi-Ed), Aboriginal Rangers and Aboriginal Healthcare Workers (Group 2: Rangers/AHWs), and patients with a history of melioidosis infection (Group 3: Patients). A questionnaire was developed to collect data on demographics, risk and protective factor awareness, and knowledge acquisition sources. We used responses to calculate indices for risk knowledge (RKI), protective knowledge (PKI), overall melioidosis knowledge (MKI), and information sources (ISI). We found that 93.6% of participants in Group 1 (Hi-Ed) said that they had heard of melioidosis, followed by 81.5% in Group 3 (Patients), and 72.0% in Group 2 (Rangers/AHWs). Group 1 (Hi-Ed) participants demonstrated greater knowledge of risk-increasing behaviours but had gaps in knowledge of clinical risks like diabetes. Multiple regression revealed that the number of resources used was the only significant predictor of MKI. There are varying melioidosis knowledge levels across different NT participant groups. Targeted educational interventions are needed to enhance melioidosis awareness. A weblink with an interactive summary of our analysis can be found under Results part.

Streptococcus dysgalactiae subsp. equisimilis (SDSE) is an emerging cause of human infection with invasive disease incidence and clinical manifestations comparable to the closely related species, Streptococcus pyogenes. Through systematic genomic analyses of 501 disseminated SDSE strains, we demonstrate extensive overlap between the genomes of SDSE and S. pyogenes. More than 75% of core genes are shared between the two species with one third demonstrating evidence of cross-species recombination. Twenty-five percent of mobile genetic element (MGE) clusters and 16 of 55 SDSE MGE insertion regions were shared across species. Assessing potential cross-protection from leading S. pyogenes vaccine candidates on SDSE, 12/34 preclinical vaccine antigen genes were shown to be present in >99% of isolates of both species. Relevant to possible vaccine evasion, six vaccine candidate genes demonstrated evidence of inter-species recombination. These findings demonstrate previously unappreciated levels of genomic overlap between these closely related pathogens with implications for streptococcal pathobiology, disease surveillance and prevention., (© 2024. The Author(s).)

Burkholderia pseudomallei, the causative agent of melioidosis, is found in soil and water of tropical and subtropical regions globally. Modelled estimates of the global burden predict that melioidosis remains vastly under-reported, and a call has been made for it to be recognized as a neglected tropical disease by the World Health Organization. Severe weather events and environmental disturbance are associated with increased case numbers, and it is anticipated that, in some regions, cases will increase in association with climate change. Genomic epidemiological investigations have confirmed B. pseudomallei endemicity in newly recognized regions, including the southern United States. Melioidosis follows environmental exposure to B. pseudomallei and is associated with comorbidities that affect the immune response, such as diabetes, and with socioeconomic disadvantage. Several vaccine candidates are ready for phase I clinical trials. In this Review, we explore the global burden, epidemiology and pathophysiology of B. pseudomallei as well as current diagnostics, treatment recommendations and preventive measures, highlighting research needs and priorities., (© 2023. Crown.)

Melioidosis is an emerging infection with increasing endemic foci and global distribution. It is underrecognized and underdiagnosed because of factors including limited awareness of the disease, nonspecific clinical presentation, lack of diagnostic facilities in some locations, misidentification in laboratories inexperienced with culture, and identification of Burkholderia pseudomallei. Cutaneous findings are reported in approximately 10% to 20% of melioidosis cases and dermatologists may play a significant role in its recognition and management. The most dynamic situation of melioidosis recognition and/or expansion currently is in the United States. Global modeling had predicted that B. pseudomallei were potentially endemic in the southern United States and endemicity with local cases of melioidosis was confirmed in 2022. With the distribution and prevalence of melioidosis increasing globally and with this recent recognition that melioidosis is now endemic in the southern United States, it is important for dermatologists to maintain high clinical suspicion in appropriate patients and be familiar with its diagnosis and treatment. Here we review the available literature on cutaneous melioidosis to evaluate its epidemiology, etiology, pathophysiology and clinical presentation and provide guidance for diagnosis and management in dermatology practice., Competing Interests: Conflicts of interest None disclosed., (Copyright © 2023 American Academy of Dermatology, Inc. Published by Elsevier Inc. All rights reserved.)

Objectives: We describe the public health response to an outbreak of acute rheumatic fever (ARF) in a remote Aboriginal community., Methods: In August 2021, the Northern Territory Rheumatic Heart Disease Control Program identified an outbreak of acute rheumatic fever in a remote Aboriginal community. A public health response was developed using a modified acute poststreptococcal glomerulonephritis protocol and the National Acute Rheumatic Fever Guideline for Public Health Units., Results: 12 cases were diagnosed during the outbreak; six-times the average number of cases in the same period in the five years prior (n=1.8). Half (n=6) of the outbreak cases were classified as recurrent episodes with overdue secondary prophylaxis. Contact tracing and screening of 11 households identified 86 close contacts., Conclusions: This outbreak represented an increase in both first episodes and recurrences of acute rheumatic fever and highlights the critical need for strengthened delivery of acute rheumatic fever secondary prophylaxis, and for improvements to the social determinants of health in the region., Implications for Public Health: Outbreaks of acute rheumatic fever are rare despite continuing high rates of acute rheumatic fever experienced by remote Aboriginal communities. Nevertheless, there can be improvements in the current national public health guidance relating to acute rheumatic fever cluster and outbreak management., Competing Interests: Conflicts of 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 © 2023 The Authors. Published by Elsevier B.V. All rights reserved.)

Objective: To describe the socio-environmental profile and clinical features of invasive group A streptococcal (iGAS) infections in the Northern Territory (NT) of Australia over 10 years., Methods: Cases of iGAS disease diagnosed between 1 May 2011 and 30 April 2021 were retrospectively identified from the NT Notifiable Diseases System and electronic health records accessed. Remoteness of residence, socio-economic index, seasonality and clinical characteristics were recorded., Results: There were 692 cases of iGAS disease identified in the NT during the period 1 May 2011 - 30 April 2021. The age-standardised incidence of iGAS disease was significantly higher in people living in very remote (57.1 cases per 100,000 population, 95% confidence interval [95% CI]: 48.6-65.5) and remote areas (40.9 cases per 100,000 population, 95% CI: 34.7-47.2) than in outer regional areas of the NT (15.7 cases per 100,000 population, 95% CI: 13.4-17.9). People with socio-economic disadvantage were also disproportionately affected, with an incidence of 52.6 cases per 100,000 population (95% CI: 46.2-58.9) in decile 1-3 populations, compared to 8.9 cases per 100,000 population (95% CI: 6.9-10.9) for decile 7-10. For cases with recorded severity data, 135 of 378 (36%) met locally-defined criteria for severe iGAS disease. Recurrent iGAS disease was commonly observed in the dialysis cohort, affecting 17 of the 106 patients during the study period (16% recurrence rate) and causing two deaths. Five molecularly-confirmed clusters of iGAS disease were identified from the study period., Conclusions: iGAS disease is unevenly affecting people in the NT. Those living in areas of socio-economic disadvantage, those in remote and very remote communities, and those receiving dialysis were most affected. It is important that primordial, primary and secondary prevention measures be directed towards supporting these disadvantaged population groups., (© Commonwealth of Australia CC BY-NC-ND)

Burkholderia pseudomallei , the causative agent of melioidosis, has not yet been reported in Timor-Leste, a sovereign state northwest of Australia. In the context of improved access to diagnostic resources and expanding clinical networks in the Australasian region, we report the first 3 cases of culture-confirmed melioidosis in Timor-Leste. These cases describe a broad range of typical presentations, including sepsis, pneumonia, multifocal abscesses, and cutaneous infection. Phylogenetic analysis revealed that the Timor-Leste isolates belong to the Australasian clade of B. pseudomallei , rather than the Asian clade, consistent with the phylogeographic separation across the Wallace Line. This study underscores an urgent need to increase awareness of this pathogen in Timor-Leste and establish diagnostic laboratories with improved culture capacity in regional hospitals. Clinical suspicion should prompt appropriate sampling and communication with laboratory staff to target diagnostic testing. Local antimicrobial guidelines have recently been revised to include recommendations for empiric treatment of severe sepsis., Competing Interests: Potential conflicts of interest. All authors: no reported conflicts., (© The Author(s) 2023. Published by Oxford University Press on behalf of Infectious Diseases Society of America.)

Background: Melioidosis, caused by the Gram-negative bacterium Burkholderia pseudomallei , has a major global health impact and a wide range of different disease manifestations. Histopathological descriptions of melioidosis remain limited. Granulomatous inflammation with multinucleated giant cells are considered classic features. We aim to present a graphical overview of histopathological manifestations of melioidosis, serving as an aid in diagnosing this disease., Methods: We performed a retrospective international multicenter laboratory-based analysis of formalin-fixed paraffin-embedded (FFPE) tissue from culture-confirmed melioidosis autopsy and biopsy cases. Available FFPE tissue was stained with hematoxylin and eosin and immunostainings including a monoclonal antibody targeting the capsular polysaccharide (CPS) of B pseudomallei . Tissue with site-specific cultures and/or positive CPS staining were included in the graphical histopathological overview., Results: We identified tissue of 8 autopsy and 5 biopsy cases. Pneumonia and soft tissue abscesses were the leading foci of disease displaying mainly necrosis and suppuration. Infrequent disease manifestations included involvement of bone marrow and adrenal glands in an autopsy case and biopsied mediastinal tissue, the latter being the only case in which we identified multinucleated giant cells. Using the CPS staining, we demonstrated granulomata as part of rare gastric tissue involvement., Conclusions: We found fatal melioidosis to be a necrotizing and suppurative inflammation, usually without multinucleated giant cell formation. Gastric and mediastinal involvement points to ingestion and inhalation as possible routes of infection. The CPS staining proved beneficial as an aid to establish a histopathological diagnosis. Our graphical overview can be used by infectious diseases specialists, microbiologists, and pathologists., Competing Interests: Potential conflicts of interest. All authors: No reported conflicts of interest., (© The Author(s) 2023. Published by Oxford University Press on behalf of Infectious Diseases Society of America.)

Background: Streptococcus pyogenes, or group A Streptococcus (GAS), infections contribute to a high burden of disease in Aboriginal Australians, causing skin infections and immune sequelae such as rheumatic heart disease. Controlling skin infections in these populations has proven difficult, with transmission dynamics being poorly understood. We aimed to identify the relative contributions of impetigo and asymptomatic throat carriage to GAS transmission., Methods: In this genomic analysis, we retrospectively applied whole genome sequencing to GAS isolates that were collected as part of an impetigo surveillance longitudinal household survey conducted in three remote Aboriginal communities in the Northern Territory of Australia between Aug 6, 2003, and June 22, 2005. We included GAS isolates from all throats and impetigo lesions of people living in two of the previously studied communities. We classified isolates into genomic lineages based on pairwise shared core genomes of more than 99% with five or fewer single nucleotide polymorphisms. We used a household network analysis of epidemiologically and genomically linked lineages to quantify the transmission of GAS within and between households., Findings: We included 320 GAS isolates in our analysis: 203 (63%) from asymptomatic throat swabs and 117 (37%) from impetigo lesions. Among 64 genomic lineages (encompassing 39 emm types) we identified 264 transmission links (involving 93% of isolates), for which the probable source was asymptomatic throat carriage in 166 (63%) and impetigo lesions in 98 (37%). Links originating from impetigo cases were more frequent between households than within households. Households were infected with GAS for a mean of 57 days (SD 39 days), and once cleared, reinfected 62 days (SD 40 days) later. Increased household size and community presence of GAS and scabies were associated with slower clearance of GAS., Interpretation: In communities with high prevalence of endemic GAS-associated skin infection, asymptomatic throat carriage is a GAS reservoir. Public health interventions such as vaccination or community infection control programmes aimed at interrupting transmission of GAS might need to include consideration of asymptomatic throat carriage., Funding: Australian National Health and Medical Research Council., Competing Interests: Declaration of interests All authors declare no competing interests., (Copyright © 2023 The Author(s). Published by Elsevier Ltd. This is an Open Access article under the CC BY-NC-ND 4.0 license. Published by Elsevier Ltd.. All rights reserved.)

Cefiderocol is a siderophore cephalosporin designed mainly for treatment of infections caused by β-lactam and multidrug-resistant Gram-negative bacteria. Burkholderia pseudomallei clinical isolates are usually highly cefiderocol susceptible, with in vitro resistance found in a few isolates. Resistance in clinical B. pseudomallei isolates from Australia is caused by a hitherto uncharacterized mechanism. We show that, like in other Gram-negatives, the PiuA outer membrane receptor plays a major role in cefiderocol nonsusceptibility in isolates from Malaysia., Competing Interests: The authors declare no conflict of interest.

Background: Cryptococcus gattii is a globally endemic pathogen causing disease in apparently immune-competent hosts. We describe a 22-year cohort study from Australia's Northern Territory to evaluate trends in epidemiology and management, and outcome predictors., Methods: A retrospective cohort study of all C. gattii infections at the northern Australian referral hospital 1996-2018 was conducted. Cases were defined as confirmed (culture-positive) or probable. Demographic, clinical and outcome data were extracted from medical records., Results: 45 individuals with C. gattii infection were included: 44 Aboriginal Australians; 35 with confirmed infection; none HIV positive out of 38 tested. Multifocal disease (pulmonary and central nervous system) occurred in 20/45 (44%). Nine people (20%) died within 12 months of diagnosis, five attributed directly to C. gattii. Significant residual disability was evident in 4/36 (11%) survivors. Predictors of mortality included: treatment before the year 2002 (4/11 versus 1/34); interruption to induction therapy (2/8 versus 3/37) and end-stage kidney disease (2/5 versus 3/40). Prolonged antifungal therapy was the standard approach in this cohort, with median treatment duration being 425 days (IQR 166-715). Ten individuals had adjunctive lung resection surgery for large pulmonary cryptococcomas (median diameter 6cm [range 2.2-10cm], versus 2.8cm [1.2-9cm] in those managed non-operatively). One died post-operatively, and 7 had thoracic surgical complications, but ultimately 9/10 (90%) treated surgically were cured compared with 10/15 (67%) who did not have lung surgery. Four patients were diagnosed with immune reconstitution inflammatory syndrome which was associated with age <40 years, brain cryptococcomas, high cerebrospinal fluid pressure, and serum cryptococcal antigen titre >1:512., Conclusion: C. gattii infection remains a challenging condition but treatment outcomes have significantly improved over 2 decades, with eradication of infection the norm. Adjunctive surgery for the management of bulky pulmonary C. gattii infection appears to increase the likelihood of durable cure and likely reduces the required duration of antifungal therapy., Competing Interests: I have read the journal’s policy and the authors of this manuscript have the following competing interests:Dr. KH has received advisory board fees and grant support from Gilead Sciences. The authors have no other conflicts to declare., (Copyright: © 2023 O’Hern et al. This is an open access article distributed under the terms of the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original author and source are credited.)

Burkholderia pseudomallei is a soil- and water-dwelling Gram-negative bacterium that causes melioidosis in humans and animals. Amoxicillin-clavulanic acid (AMC) susceptibility has been hailed as an integral part of the screening algorithm for identification of B. pseudomallei, but the molecular basis for the inherent AMC susceptibility of this bacterium remains undefined. This study showed that B. pseudomallei (and the closely-related B. mallei) wild-type strains are the only Burkholderia spp. that contain a 70 STSK 73 PenA Ambler motif. This motif was present in >99.5% of 1820 analysed B. pseudomallei strains and 100% of 83 analysed B. mallei strains, and is proposed as the likely cause for their inherent AMC sensitivity. The authors developed a polymerase chain reaction (PCR) assay that specifically amplifies the penA 70 ST(S/F)K 73 -containing region from B. pseudomallei and B. mallei, but not from the remaining B. pseudomallei complex species or the 70 STFK 73 region from the closely-related penB of B. cepacia complex species. The abundance and purity of the 193-bp PCR fragment from putative B. pseudomallei isolates from clinical and environmental samples is likely sufficient for reliable confirmation of the presence of B. pseudomallei. The PCR assay is designed to be especially suited for use in resource-constrained areas. While not further explored in this study, the assay may allow diagnosis of putative B. mallei in culture isolates from animal and human samples., (Copyright © 2023 The Authors. Published by Elsevier Ltd.. All rights reserved.)

Burkholderia pseudomallei, the causative agent of melioidosis, is a gram-negative soil bacterium well recognized in Southeast Asia and northern Australia. However, wider and expanding global distribution of B. pseudomallei has been elucidated. Early diagnosis is critical for commencing the specific therapy required to optimize outcome. Serological testing using the indirect hemagglutination (IHA) antibody assay has long been used to augment diagnosis of melioidosis and to monitor progress. However, cross reactivity and prior exposure may complicate the diagnosis of current clinical disease (melioidosis). The goal of our study was to develop and initially evaluate a serology assay (BurkPx) that capitalized upon host response to multiple antigens. Antigens were selected from previous studies for expression/purification and conjugation to microspheres for multiantigen analysis. Selected serum samples from non-melioidosis controls and serial samples from culture-confirmed melioidosis patients were used to characterize the diagnostic power of individual and combined antigens at two times post admission. Multiple variable models were developed to evaluate multivariate antigen reactivity, identify important antigens, and determine sensitivity and specificity for the diagnosis of melioidosis. The final multiplex assay had a diagnostic sensitivity of 90% and specificity of 93%, which was superior to any single antigen in side-by-side comparisons. The sensitivity of the assay started at >85% for the initial serum sample after admission and increased to 94% 21 days later. Weighting antigen contribution to each model indicated that certain antigen contributed to diagnosis more than others, which suggests that the number of antigens in the assay can be decreased. In summation, the BurkPx assay can facilitate the diagnosis of melioidosis and potentially improve on currently available serology assays. Further evaluation is now required in both melioidosis-endemic and non-endemic settings., Competing Interests: The authors have no competing interests., (Copyright: © 2023 Settles et al. This is an open access article distributed under the terms of the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original author and source are credited.)

Melioidosis is a neglected tropical disease that causes high morbidity and mortality. Public health awareness is essential for both prevention and early detection of the infection. This project aimed to develop an internationally applicable educational tool to increase community awareness in regions with high prevalence of diabetes and melioidosis. The animation was created with international collaboration. Sixty-four delegates from different cultural backgrounds participated in the survey to evaluate the animation. Feedback was positive, with 85% agreeing that they would use this video for public education and 82% agreeing that the video was culturally appropriate to them in the context of their region. The animation was refined after feedback. To supplement the 3-minute animation, a 13-minute film footage of interviews with clinicians, researchers and patients was also created. These materials have been made available online through the International Melioidosis Network and can be readily downloaded or subtitled in any language using publicly available software, demonstrating the utility of developing low-cost adaptable health education material targeted for widespread use internationally.

Purpose of Review: Melioidosis and its causative bacterium Burkholderia pseudomallei are being found in unexpected locations and bacterial genotyping is providing new insights into global spread and where and how individuals are being infected. This review summarizes recent studies covering the epidemiology, diagnosis, treatment, and prevention of melioidosis., Recent Findings: Whole-genome sequencing of B. pseudomallei from patients and environmental sampling is informing the phylogeography of B. pseudomallei at regional, continental, and global levels, while also defining the epidemiology for individual cases. The situation in Africa remains the most unresolved, while the evolving story of B. pseudomallei in the Americas may establish that B. pseudomallei is endemic in parts of southern USA. Guidelines for diagnosis and treatment of melioidosis are well established, and published mortality has decreased from 50% or higher to 10% or lower in some countries but access to laboratory and therapeutic resources are not available or are extremely limited in many melioidosis-endemic regions., Summary: The enormous clinical diversity of melioidosis and the complexities of laboratory diagnosis and of treatment make it a sentinel disease for highlighting the continuing global disparities in access to and provision of healthcare., (Copyright © 2022 Wolters Kluwer Health, Inc. All rights reserved.)

Background: A fatal case of Japanese encephalitis (JE) occurred in a resident of the Tiwi Islands, in the Northern Territory of Australia in February 2021, preceding the large JE outbreak in south-eastern Australia in 2022. This study reports the detection, whole genome sequencing and analysis of the virus responsible (designated JEV/Australia/NT&#95;Tiwi Islands/2021)., Methods: Reverse transcription quantitative PCR (RT-qPCR) testing was performed on post-mortem brain specimens using a range of JE virus (JEV)-specific assays. Virus isolation from brain specimens was attempted by inoculation of mosquito and mammalian cells or embryonated chicken eggs. Whole genome sequencing was undertaken using a combination of Illumina next generation sequencing methodologies, including a tiling amplicon approach. Phylogenetic and selection analyses were performed using alignments of the Tiwi Islands JEV genome and envelope (E) protein gene sequences and publicly available JEV sequences., Results: Virus isolation was unsuccessful and JEV RNA was detected only by RT-qPCR assays capable of detecting all JEV genotypes. Phylogenetic analysis revealed that the Tiwi Islands strain is a divergent member of genotype IV (GIV) and is closely related to the 2022 Australian outbreak virus (99.8% nucleotide identity). The Australian strains share highest levels of nucleotide identity with Indonesian viruses from 2017 and 2019 (96.7-96.8%). The most recent common ancestor of this Australian-Indonesian clade was estimated to have emerged in 2007 (95% HPD range: 1998-2014). Positive selection was detected using two methods (MEME and FEL) at several sites in the E and non-structural protein genes, including a single site in the E protein (S194N) unique to the Australian GIV strains., Conclusion: This case represents the first detection of GIV JEV acquired in Australia, and only the second confirmed fatal human infection with a GIV JEV strain. The close phylogenetic relationship between the Tiwi Islands strain and recent Indonesian viruses is indicative of the origin of this novel GIV lineage, which we estimate has circulated in the region for several years prior to the Tiwi Islands case., Competing Interests: The authors have declared that no competing interests exist., (Copyright: © 2022 Sikazwe et al. This is an open access article distributed under the terms of the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original author and source are credited.)

A fatal case of Japanese encephalitis (JE) occurred in northern Australia in early 2021. Sequence studies showed that the virus belonged to genotype IV (GIV), a genotype previously believed to be restricted to the Indonesian archipelago. This was the first locally acquired case of Japanese encephalitis virus (JEV) GIV to occur outside Indonesia, and the second confirmed fatal human case caused by a GIV virus. A closely related GIV JEV strain subsequently caused a widespread outbreak in eastern Australia in 2022 that was first detected by fetal death and abnormalities in commercial piggeries. Forty-two human cases also occurred with seven fatalities. This has been the first major outbreak of JEV in mainland Australia, and geographically the largest virgin soil outbreak recorded for JEV. This outbreak provides an opportunity to discuss and document the factors involved in the virus' spread and its ecology in a novel ecological milieu in which other flaviviruses, including members of the JE serological complex, also occur. The probable vertebrate hosts and mosquito vectors are discussed with respect to virus spread and its possible endemicity in Australia, and the need to develop a One Health approach to develop improved surveillance methods to rapidly detect future outbreak activity across a large geographical area containing a sparse human population. Understanding the spread of JEV in a novel ecological environment is relevant to the possible threat that JEV may pose in the future to other receptive geographic areas, such as the west coast of the United States, southern Europe or Africa.

The Northern Territory (NT) is a geographically remote region of northern and central Australia. Approximately a third of the population are First Nations Australians, many of whom live in remote regions. Due to the physical environment and climate, and scale of social inequity, the rates of many infectious diseases are the highest nationally. Molecular typing and genomic sequencing in research and public health have provided considerable new knowledge on the epidemiology of infectious diseases in the NT. We review the applications of genomic sequencing technology for molecular typing, identification of transmission clusters, phylogenomics, antimicrobial resistance prediction, and pathogen detection. We provide examples where these methodologies have been applied to infectious diseases in the NT and discuss the next steps in public health implementation of this technology.

The goals of acute rheumatic fever therapy are to relieve symptoms, mitigate cardiac valve damage and eradicate streptococcal infection. Preventing future recurrences requires long-term secondary antibiotic prophylaxis and ongoing prevention of Streptococcus pyogenes (group A streptococcus) infections The recommended regimen for secondary prophylaxis comprises benzathine benzylpenicillin G intramuscular injections every four weeks. For patients with non-severe or immediate penicillin hypersensitivity, use erythromycin orally twice daily The goals of therapy for rheumatic heart disease are to prevent progression and optimise cardiac function. Secondary antibiotic prophylaxis can reduce the long-term severity of rheumatic heart disease Patients with rheumatic heart disease, including those receiving benzathine benzylpenicillin G prophylaxis, should receive amoxicillin prophylaxis before undergoing high-risk dental or surgical procedures. If they have recently been treated with a course of penicillin or amoxicillin, or have immediate penicillin hypersensitivity, clindamycin is recommended., ((c) NPS MedicineWise.)

Melioidosis is endemic in the remote Katherine region of northern Australia. In a population with high rates of chronic disease, social inequities, and extreme remoteness, the impact of melioidosis is exacerbated by severe weather events and disproportionately affects First Nations Australians. All culture-confirmed melioidosis cases in the Katherine region of the Australian Top End between 1989-2021 were included in the study, and the clinical features and epidemiology were described. The diversity of Burkholderia pseudomallei strains in the region was investigated using genomic sequencing. From 1989-2021 there were 128 patients with melioidosis in the Katherine region. 96/128 (75%) patients were First Nations Australians, 72/128 (56%) were from a very remote region, 68/128 (53%) had diabetes, 57/128 (44%) had a history of hazardous alcohol consumption, and 11/128 (9%) died from melioidosis. There were 9 melioidosis cases attributable to the flooding of the Katherine River in January 1998; 7/9 flood-associated cases had cutaneous melioidosis, five of whom recalled an inoculating event injury sustained wading through flood waters or cleaning up after the flood. The 126 first-episode clinical B. pseudomallei isolates that underwent genomic sequencing belonged to 107 different sequence types and were highly diverse, reflecting the vast geographic area of the study region. In conclusion, melioidosis in the Katherine region disproportionately affects First Nations Australians with risk factors and is exacerbated by severe weather events. Diabetes management, public health intervention for hazardous alcohol consumption, provision of housing to address homelessness, and patient education on melioidosis prevention in First Nations languages should be prioritised., Competing Interests: The authors have declared that no competing interests exist.

Melioidosis is a tropical infection caused by the soil bacterium Burkholderia pseudomallei. Despite the substantial impact of this often overlooked pathogen on both the health-care systems and economies of numerous low-income and middle-income countries around the world, melioidosis is not officially classified as a neglected tropical disease (NTD) by WHO. Melioidosis causes a higher estimated disease burden and mortality than many other recognised NTDs, with deaths primarily occurring among rural poor populations in low-income and middle-income countries. Fortunately, the impact of melioidosis in a region can be reduced once awareness is established of its known or suspected endemicity. In this Personal View, we provide evidence in support of official recognition of melioidosis as an NTD. We urge member states to request that WHO revisit their NTD list and appeal to government and philanthropic organisations to establish programmes in endemic countries to control melioidosis in order to reduce its global health burden., Competing Interests: Declaration of interests DABD acts as a consultant to InBios International in relation to the development of rapid diagnostics for melioidosis. The other authors declare no competing interests., (Copyright © 2022 Elsevier Ltd. All rights reserved.)

Background: Acute Rheumatic Fever (ARF) is a critically important condition for which there is no diagnostic test. Diagnosis requires the use of a set of criteria comprising clinical, laboratory, electrocardiographic and echocardiographic findings. The complexity of the algorithm and the fact that clinicians lack familiarity with ARF, make ARF diagnosis ideally suited to an electronic decision support tool. The ARF Diagnosis Calculator was developed to assist clinicians in diagnosing ARF and correctly assign categories of 'possible, 'probable' or 'definite' ARF. This research aimed to evaluate the acceptability, accuracy, and test performance of the ARF Diagnosis Calculator., Methods: Three strategies were used to provide triangulation of data. Users of the calculator employed at Top End Health Service, Northern Territory, Australia were invited to participate in an online survey, and clinicians with ARF expertise were invited to participate in semi-structured interviews. Qualitative data were analysed using inductive analysis. Performance of the calculator in correctly diagnosing ARF was assessed using clinical data from 35 patients presenting with suspected ARF. Diagnoses obtained from the calculator were compared using the Kappa statistic with those obtained from a panel of expert clinicians., Results: Survey responses were available from 23 Top End Health Service medical practitioners, and interview data were available from five expert clinicians. Using a 6-point Likert scale, participants highly recommended the ARF Diagnosis Calculator (median 6, IQR 1), found it easy to use (median 5, IQR 1) and believed the calculator helped them diagnose ARF (median 5, IQR 1). Clinicians with ARF expertise noted that electronic decision making is not a substitute for clinical experience. There was high agreement between the ARF Diagnosis Calculator and the 'gold standard' ARF diagnostic process (κ = 0.767, 95% CI: 0.568-0.967). Incorrect assignment of diagnosis occurred in 4/35 (11%) patients highlighting the greater accuracy of expert clinical input for ambiguous presentations. Sixteen changes were incorporated into a revised version of the calculator., Conclusions: The ARF Diagnosis Calculator is an easy-to-use, accessible tool, but it does not replace clinical expertise. The calculator performed well amongst clinicians and is an acceptable tool for use within the clinical setting with a high level of accuracy in comparison to the gold standard diagnostic process. Effective resources to support clinicians are critically important for improving the quality of care of ARF., (© 2022. The Author(s).)

Background: Culture of Burkholderia pseudomallei remains the gold standard for diagnosis of melioidosis but is not possible in many resource-limited settings where melioidosis is endemic. Direct identification of B. pseudomallei antigen in clinical samples has been developed using a lateral flow immunoassay (LFA) targeting B. pseudomallei capsular polysaccharide., Methods: We summarized the findings from the 8 studies to date of the Active Melioidosis Detect (AMD) LFA and compared these with our results from 232 patients with culture-confirmed melioidosis. We have also optimized the methodology for testing different clinical samples., Results: Sensitivity and specificity for different samples were broadly similar in our study to those published from Thailand, India, Laos, and Malaysia. One hundred thirty of 232 (56%) of our melioidosis patients were positive on 1 or more AMD tests: 27% for serum (rising to 39% in those with bacteremic melioidosis and 68% in those with septic shock), 63% for urine (72% in bacteremic melioidosis and 90% in septic shock), 85% in sputum that was culture positive, and 83% in pus that was culture positive. Heating sputum and pus samples increased sensitivity. Faint false-positive urine bands seen on earlier AMD versions were not seen when retested using the most recent version, AMD-Plus., Conclusions: While the sensitivity of melioidosis LFA is low overall for blood samples, there is potential for use as a rapid diagnostic: testing serum and urine from those with severe sepsis who may have melioidosis and testing sputum and pus samples from clinically relevant scenarios. Prospective studies of patients with sepsis and other clinical presentations resembling melioidosis are required to ascertain if the specificity of AMD-PLUS is adequate to enable diagnosis of melioidosis with a high positive predictive value., (© The Author(s) 2022. Published by Oxford University Press on behalf of Infectious Diseases Society of America.)

Each case of melioidosis results from a single event when a human is infected by the environmental bacterium Burkholderia pseudomallei. Darwin, in tropical northern Australia, has the highest incidences of melioidosis globally, and the Darwin Prospective Melioidosis Study (DPMS) commenced in 1989, documenting all culture-confirmed melioidosis cases. From 2000 to 2019, we sampled DPMS patients' environments for B. pseudomallei when a specific location was considered to be where infection occurred, with the aim of using genomic epidemiology to understand B. pseudomallei transmission and infecting scenarios. Environmental sampling was performed at 98 DPMS patient sites, where we collected 975 environmental samples (742 soil and 233 water). Genotyping matched the clinical and epidemiologically linked environmental B. pseudomallei for 19 patients (19%), with the environmental isolates cultured from soil ( n  = 11) and water ( n  = 8) sources. B. pseudomallei isolates from patients and their local environments that matched on genotyping were subjected to whole-genome sequencing (WGS). Of the 19 patients with a clinical-environmental genotype match, 17 pairs clustered on a Darwin core genome single-nucleotide polymorphism (SNP) phylogeny, later confirmed by single sequence typing (ST) phylogenies and pairwise comparative genomics. When related back to patient clinical scenarios, the matched clinical and environmental B. pseudomallei pairs informed likely modes of infection: percutaneous inoculation, inhalation, and ingestion. Targeted environmental sampling for B. pseudomallei can inform infecting scenarios for melioidosis and dangerous occupational and recreational activities and identify hot spots of B. pseudomallei presence. However, WGS and careful genomics are required to avoid overcalling the relatedness between clinical and environmental isolates of B. pseudomallei.

Melioidosis, caused by the bacterium Burkholderia pseudomallei, is an uncommon infection that is typically associated with exposure to soil and water in tropical and subtropical environments. It is rarely diagnosed in the continental United States. Patients with melioidosis in the United States commonly report travel to regions where melioidosis is endemic. We report a cluster of four non-travel-associated cases of melioidosis in Georgia, Kansas, Minnesota, and Texas. These cases were caused by the same strain of B. pseudomallei that was linked to an aromatherapy spray product imported from a melioidosis-endemic area., (Copyright © 2022 Massachusetts Medical Society.)

Background: The autotransporter protein Burkholderia intracellular motility A (BimA) facilitates the entry of Burkholderia pseudomallei into the central nervous system (CNS) in mouse models of melioidosis. Its role in the pathogenesis of human cases of CNS melioidosis is incompletely defined., Methods: Consecutive culture-confirmed cases of melioidosis at two sites in tropical Australia after 1989 were reviewed. Demographic, clinical and radiological data of the patients with CNS melioidosis were recorded. The bimA allele (bimABm or bimABp) of the B. pseudomallei isolated from each patient was determined., Results: Of the 1587 cases diagnosed at the two sites during the study period, 52 (3.3%) had confirmed CNS melioidosis; 20 (38.5%) had a brain abscess, 18 (34.6%) had encephalomyelitis, 4 (7.7%) had isolated meningitis and 10 (19.2%) had extra-meningeal disease. Among the 52 patients, there were 8 (15.4%) deaths; 17/44 (38.6%) survivors had residual disability. The bimA allele was characterized in 47/52; 17/47 (36.2%) had the bimABm allele and 30 (63.8%) had the bimABp allele. Patients with a bimABm variant were more likely to have a predominantly neurological presentation (odds ratio (OR) (95% confidence interval (CI)): 5.60 (1.52-20.61), p=0.01), to have brainstem involvement (OR (95%CI): 7.33 (1.92-27.95), p=0.004) and to have encephalomyelitis (OR (95%CI): 4.69 (1.30-16.95), p=0.02. Patients with a bimABm variant were more likely to die or have residual disability (odds ratio (95%CI): 4.88 (1.28-18.57), p=0.01)., Conclusions: The bimA allele of B. pseudomallei has a significant impact on the clinical presentation and outcome of patients with CNS melioidosis., (© The Author(s) 2022. Published by Oxford University Press for the Infectious Diseases Society of America. All rights reserved. For permissions, e-mail: journals.permissions@oup.com.)

Background: Snakebite-associated thrombotic microangiopathy (TMA) occurs in a subset of patients with venom-induced consumption coagulopathy (VICC) following snakebite. Acute kidney injury (AKI) is the commonest end-organ manifestation of TMA. The epidemiology, diagnostic features, outcomes, and effectiveness of interventions including therapeutic plasma-exchange (TPE), in snakebite-associated TMA are poorly understood., Methods: We reviewed all patients with suspected or confirmed snakebite recruited to the Australian Snakebite Project (2004-2018 inclusive), a prospective cohort study, from 202 participating Australian hospitals across the country. TMA was defined as anemia with schistocytosis., Results: 2069 patients with suspected snakebite were enrolled, with 1158 (56.0%) systemically envenomed, of which 842 (72.7%) developed VICC, from which 104 (12.4%) developed TMA. Of those systemically envenomed, TMA occurred in 26% (13/50) taipan, 17% (60/351) brown, and 8% (16/197) tiger snakebites. Thrombocytopenia was present in 90% (94/104) of TMA cases, and a further eight (8%) had a > 25% decrease in platelets from the presentation. Patients with TMA were significantly older than non-TMA patients with VICC (53 [35-61] versus 41 [24-55] years, median [IQR], p  < 0.0001). AKI developed in 94% (98/104) of TMA patients, with 34% (33/98) requiring dialysis (D-AKI). There were four deaths. In D-AKI TMA cases, eventual dialysis-free survival (DFS) was 97% (32/33). TPE was used in five D-AKI cases, with no significant difference in DFS or time to independence from dialysis. >90-day follow-up for 25 D-AKI cases (130 person-years) showed no end-stage kidney disease but 52% (13/25) had ≥ stage 3 chronic kidney disease (CKD)., Conclusion: Our findings support a definition of snakebite-associated TMA as anemia with schistocytosis and either thrombocytopenia or >25% drop in platelet count. AKI occurring with snakebite-associated TMA varied in severity, with most achieving DFS, but with a risk of long-term CKD in half. We found no evidence of benefit for TPE in D-AKI.

Snakebite is a significant and under-resourced global public health issue. Snake venoms cause a variety of potentially fatal clinical toxin syndromes, including venom-induced consumption coagulopathy (VICC) which is associated with major haemorrhage. A subset of patients with VICC develop a thrombotic microangiopathy (TMA). This article reviews recent evidence regarding snakebite-associated TMA and its epidemiology, diagnosis, outcomes, and effectiveness of interventions including antivenom and therapeutic plasma-exchange. Snakebite-associated TMA presents with microangiopathic haemolytic anaemia (evidenced by schistocytes on the blood film), thrombocytopenia in almost all cases, and a spectrum of acute kidney injury (AKI). A proportion of patients require dialysis, most survive and achieve dialysis free survival. There is no evidence that antivenom prevents TMA specifically, but early antivenom remains the mainstay of treatment for snake envenoming. There is no evidence for therapeutic plasma-exchange being effective. We propose diagnostic criteria for snakebite-associated TMA as anaemia with >1.0% schistocytes on blood film examination, together with absolute thrombocytopenia (<150 × 10 9 /L) or a relative decrease in platelet count of >25% from baseline. Patients are at risk of long-term chronic kidney disease and long term follow up is recommended.

Distinct Burkholderia strains were isolated from soil samples collected in tropical northern Australia (Northern Territory and the Torres Strait Islands, Queensland). Phylogenetic analysis of 16S rRNA and whole genome sequences revealed these strains were distinct from previously described Burkholderia species and assigned them to two novel clades within the B. pseudomallei complex (Bpc). Because average nucleotide identity and digital DNA-DNA hybridization calculations are consistent with these clades representing distinct species, we propose the names Burkholderia mayonis sp. nov. and Burkholderia savannae sp. nov. Strains assigned to B. mayonis sp. nov. include type strain BDU6 T (=TSD-80; LMG 29941; ASM152374v2) and BDU8. Strains assigned to B. savannae sp. nov. include type strain MSMB266 T (=TSD-82; LMG 29940; ASM152444v2), MSMB852, BDU18, and BDU19. Comparative genomics revealed unique coding regions for both putative species, including clusters of orthologous genes associated with phage. Type strains of both B. mayonis sp. nov. and B. savannae sp. nov. yielded biochemical profiles distinct from each other and from other species in the Bpc, and profiles also varied among strains within B. mayonis sp. nov. and B. savannae sp. nov. Matrix-assisted laser desorption ionization time-of-flight (MLST) analysis revealed a B. savannae sp. nov. cluster separate from other species, whereas B. mayonis sp. nov. strains did not form a distinct cluster. Neither B. mayonis sp. nov. nor B. savannae sp. nov. caused mortality in mice when delivered via the subcutaneous route. The addition of B. mayonis sp. nov. and B. savannae sp. nov. results in a total of eight species currently within the Bpc. IMPORTANCE Burkholderia species can be important sources of novel natural products, and new species are of interest to diverse scientific disciplines. Although many Burkholderia species are saprophytic, Burkholderia pseudomallei is the causative agent of the disease melioidosis. Understanding the genomics and virulence of the closest relatives to B. pseudomallei, i.e., the other species within the B. pseudomallei complex (Bpc), is important for identifying robust diagnostic targets specific to B. pseudomallei and for understanding the evolution of virulence in B. pseudomallei. Two proposed novel species, B. mayonis sp. nov. and B. savannae sp. nov., were isolated from soil samples collected from multiple locations in northern Australia. The two proposed species belong to the Bpc but are phylogenetically distinct from all other members of this complex. The addition of B. mayonis sp. nov. and B. savannae sp. nov. results in a total of eight species within this significant complex of bacteria that are available for future studies.

Bacteria that occupy an intracellular niche can evade extracellular host immune responses and antimicrobial molecules. In addition to classic intracellular pathogens, other bacteria including uropathogenic Escherichia coli (UPEC) can adopt both extracellular and intracellular lifestyles. UPEC intracellular survival and replication complicates treatment, as many therapeutic molecules do not effectively reach all components of the infection cycle. In this study, we explored cell-penetrating antimicrobial peptides from distinct structural classes as alternative molecules for targeting bacteria. We identified two β-hairpin peptides from the horseshoe crab, tachyplesin I and polyphemusin I, with broad antimicrobial activity toward a panel of pathogenic and non-pathogenic bacteria in planktonic form. Peptide analogs [I11A]tachyplesin I and [I11S]tachyplesin I maintained activity toward bacteria, but were less toxic to mammalian cells than native tachyplesin I. This important increase in therapeutic window allowed treatment with higher concentrations of [I11A]tachyplesin I and [I11S]tachyplesin I, to significantly reduce intramacrophage survival of UPEC in an in vitro infection model. Mechanistic studies using bacterial cells, model membranes and cell membrane extracts, suggest that tachyplesin I and polyphemusin I peptides kill UPEC by selectively binding and disrupting bacterial cell membranes. Moreover, treatment of UPEC with sublethal peptide concentrations increased zinc toxicity and enhanced innate macrophage antimicrobial pathways. In summary, our combined data show that cell-penetrating peptides are attractive alternatives to traditional small molecule antibiotics for treating UPEC infection, and that optimization of native peptide sequences can deliver effective antimicrobials for targeting bacteria in extracellular and intracellular environments., (© 2021. The Author(s), under exclusive licence to Springer Nature Switzerland AG.)

Background: The global distribution of melioidosis is under considerable scrutiny, with both unmasking of endemic disease in African and Pacific nations and evidence of more recent dispersal in the Americas. Because of the high incidence of disease in tropical northern Australia, The Darwin Prospective Melioidosis Study commenced in October, 1989. We present epidemiology, clinical features, outcomes, and bacterial genomics from this 30-year study, highlighting changes in the past decade., Methods: The present study was a prospective analysis of epidemiological, clinical, and laboratory data for all culture-confirmed melioidosis cases from the tropical Northern Territory of Australia from Oct 1, 1989, until Sept 30, 2019. Cases were identified on the basis of culture-confirmed melioidosis, a laboratory-notifiable disease in the Northern Territory of Australia. Patients who were culture-positive were included in the study. Multivariable analysis determined predictors of clinical presentations and outcome. Incidence, survival, and cluster analyses were facilitated by population and rainfall data and genotyping of Burkholderia pseudomallei, including multilocus sequence typing and whole-genome sequencing., Findings: There were 1148 individuals with culture-confirmed melioidosis, of whom 133 (12%) died. Median age was 50 years (IQR 38-60), 48 (4%) study participants were children younger than 15 years of age, 721 (63%) were male individuals, and 600 (52%) Indigenous Australians. All but 186 (16%) had clinical risk factors, 513 (45%) had diabetes, and 455 (40%) hazardous alcohol use. Only three (2%) of 133 fatalities had no identified risk. Pneumonia was the most common presentation occurring in 595 (52%) patients. Bacteraemia occurred in 633 (56%) of 1135 patients, septic shock in 240 (21%) patients, and 180 (16%) patients required mechanical ventilation. Cases correlated with rainfall, with 80% of infections occurring during the wet season (November to April). Median annual incidence was 20·5 cases per 100 000 people; the highest annual incidence in Indigenous Australians was 103·6 per 100 000 in 2011-12. Over the 30 years, annual incidences increased, as did the proportion of patients with diabetes, although mortality decreased to 17 (6%) of 278 patients over the past 5 years. Genotyping of B pseudomallei confirmed case clusters linked to environmental sources and defined evolving and new sequence types., Interpretation: Melioidosis is an opportunistic infection with a diverse spectrum of clinical presentations and severity. With early diagnosis, specific antimicrobial therapy, and state-of-the-art intensive care, mortality can be reduced to less than 10%. However, mortality remains much higher in the many endemic regions where health resources remain scarce. Genotyping of B pseudomallei informs evolving local and global epidemiology., Funding: The Australian National Health and Medical Research Council., Competing Interests: Declaration of interests We declare no competing interests., (Copyright © 2021 Elsevier Ltd. All rights reserved.)

Introduction: The major systemic manifestation of hemotoxicity in human snakebite envenoming is venom-induced consumption coagulopathy (VICC). A subset of patients with VICC develop thrombotic microangiopathy (TMA), in which acute kidney injury (AKI) occurs. We aimed to investigate the association between schistocytosis in snakebite patients with VICC and AKI, compared to non-envenomed patients., Methods: Serial blood films collected from a prospective cohort of snakebite patients (Australian Snakebite Project) were examined. Cases were classified a priori as non-envenomed snakebites (normal controls), envenomed without VICC, partial VICC without AKI, complete VICC without AKI, and VICC with AKI based on defined clinical and laboratory criteria. The percentage of schistocytes between groups was compared and correlated by Kendall's tau b test., Results: Seven hundred and eighty blood films from 234 snakebite cases were analyzed. There was a statistically significant correlation (τ = .69, SE .03, P < .001) for schistocytosis between the ordered groups of non-envenomed snakebites, envenomed without VICC, partial VICC without AKI, complete VICC without AKI, and VICC with AKI groups. Patients with VICC and AKI had a platelet nadir median of 42 × 10 9 /L (interquartile range [IQR] :25-130 × 10 9 /L), hemoglobin nadir of median 107 g/L (IQR 66-122 g/L), and maximum LDH median of 1128 U/L (IQR 474-3255 U/L). A 1.0% threshold for schistocytosis yielded 90% sensitivity (95% CI: 67%-98%) and 71% specificity (95% CI: 62%-79%) for predicting AKI in patients with VICC., Conclusion: Schistocyte quantitation has good diagnostic utility in snakebite patients with VICC. A definition of snakebite TMA as MAHA with ≥1.0% schistocytes and thrombocytopenia, would appear to be appropriate., (© 2021 The Authors. International Journal of Laboratory Hematology published by John Wiley & Sons Ltd.)