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Dadwal P, Bonner B, Fraser D, Loveridge J, Withey G, Puri A, Smith S, Hanson J. Bone and joint infections due to melioidosis; diagnostic and management strategies to optimise outcomes. PLoS Negl Trop Dis 2024; 18:e0012317. [PMID: 39018296 PMCID: PMC11253972 DOI: 10.1371/journal.pntd.0012317] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/15/2024] [Accepted: 06/24/2024] [Indexed: 07/19/2024] Open
Abstract
BACKGROUND Melioidosis, a life-threatening infection caused by the gram negative bacterium Burkholderia pseudomallei, can involve almost any organ. Bone and joint infections (BJI) are a recognised, but incompletely defined, manifestation of melioidosis that are associated with significant morbidity and mortality in resource-limited settings. METHODOLOGY/PRINCIPAL FINDINGS We identified all individuals with BJI due to B. pseudomallei managed at Cairns Hospital in tropical Australia between January 1998 and June 2023. The patients' demographics, their clinical findings and their treatment were correlated with their subsequent course. Of 477 culture-confirmed cases of melioidosis managed at the hospital during the study period, 39 (8%) had confirmed BJI; predisposing risk factors for melioidosis were present in 37/39 (95%). However, in multivariable analysis only diabetes mellitus was independently associated with the presence of BJI (odds ratio (95% confidence interval): 4.04 (1.81-9.00), p = 0.001). BJI was frequently only one component of multi-organ involvement: 29/39 (74%) had infection involving other organs and bacteraemia was present in 31/39 (79%). Of the 39 individuals with BJI, 14 (36%) had osteomyelitis, 8 (20%) had septic arthritis and 17 (44%) had both osteomyelitis and septic arthritis; in 32/39 (83%) the lower limb was involved. Surgery was performed in 30/39 (77%). Readmission after the initial hospitalisation was necessary in 11/39 (28%), 5/39 (13%) had disease recrudescence and 3/39 (8%) had relapse; 4/39 (10%) developed pathological fractures. ICU admission was necessary in 11/39 (28%) but all 11 of these patients survived. Only 1/39 (3%) died, 138 days after admission, due to his significant underlying comorbidity. CONCLUSIONS The case-fatality rate from melioidosis BJI in Australia's well-resourced health system is very low. However, recrudescence, relapse and orthopaedic complications are relatively common and emphasise the importance of collaborative multidisciplinary care that includes early surgical review, aggressive source control, prolonged antibiotic therapy, and thorough, extended follow-up.
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Affiliation(s)
- Parvati Dadwal
- Department of Orthopaedic Surgery, Cairns Hospital, Cairns, Queensland, Australia
- James Cook University, Cairns, Queensland, Australia
| | - Brady Bonner
- Department of Orthopaedic Surgery, Logan Hospital, Brisbane, Queensland, Australia
| | - David Fraser
- Department of Orthopaedics, Prince Charles Hospital, Brisbane, Queensland, Australia
| | - Jeremy Loveridge
- James Cook University, Cairns, Queensland, Australia
- Far North Queensland Hand Surgery, Cairns, Queensland, Australia
| | - Grant Withey
- Department of Radiology, Cairns Hospital, Cairns, Queensland, Australia
| | - Arvind Puri
- Department of Orthopaedic Surgery, Cairns Hospital, Cairns, Queensland, Australia
| | - Simon Smith
- Department of Medicine, Cairns Hospital, Cairns, Queensland Australia
| | - Josh Hanson
- Department of Medicine, Cairns Hospital, Cairns, Queensland Australia
- The Kirby Institute, University of New South Wales, Sydney, New South Wales, Australia
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Baker K, Duncan T, Kung S, Smith S, Hanson J. Melioidosis masquerading as malignancy in tropical Australia; lessons for clinicians and implications for clinical management. Acta Trop 2024; 254:107209. [PMID: 38599443 DOI: 10.1016/j.actatropica.2024.107209] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/19/2024] [Revised: 03/19/2024] [Accepted: 04/07/2024] [Indexed: 04/12/2024]
Abstract
Melioidosis is a life-threatening, emerging infectious disease caused by the environmental bacterium Burkholderia pseudomallei. Melioidosis is hyperendemic in tropical Australia and southeast Asia, however the disease is increasingly encountered beyond these regions. Early diagnosis is essential as the infection has a case-fatality rate of up to 50 %. Melioidosis most commonly involves the lungs, although almost any organ can be affected. Most patients present acutely but an insidious presentation over weeks to months is also well described. We present a case series of 7 patients from tropical Australia whom local clinicians initially believed to have cancer ‒ most commonly lung cancer ‒ only for further investigation to establish a diagnosis of melioidosis. All 7 patients had comorbidities that predisposed them to developing melioidosis and all survived, but their delayed diagnosis resulted in 3 receiving anti-cancer therapies that resulted in significant morbidity. The study emphasises the importance of thorough diagnostic evaluation and repeated collection of microbiological samples. It is hoped that our experience will encourage other clinicians ‒ in the appropriate clinical context ‒ to consider melioidosis as a potential explanation for a patient's presentation, expediting its diagnosis and the initiation of potentially life-saving therapy.
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Affiliation(s)
- Kelly Baker
- Department of Medicine, Cairns Hospital, Cairns, Queensland, Australia
| | - Ty Duncan
- Department of Radiology, Cairns Hospital, Cairns, Queensland, Australia
| | - Samantha Kung
- Department of Medicine, Cairns Hospital, Cairns, Queensland, Australia
| | - Simon Smith
- Department of Medicine, Cairns Hospital, Cairns, Queensland, Australia
| | - Josh Hanson
- Department of Medicine, Cairns Hospital, Cairns, Queensland, Australia; Kirby Institute, University of New South Wales, Sydney, New South Wales, Australia.
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Jarrett O, Seng S, Fitzgerald DA. Paediatric melioidosis. Paediatr Respir Rev 2024; 50:31-37. [PMID: 38245464 DOI: 10.1016/j.prrv.2023.11.002] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 11/17/2023] [Accepted: 11/17/2023] [Indexed: 01/22/2024]
Abstract
Melioidosis is a tropical infectious disease caused by the saprophytic gram-negative bacterium Burkholderia pseudomallei. Despite the infection being endemic in southeast Asia and northern Australia, the broad clinical presentations and diagnostic difficulties limit its early detection, particularly in children. Melioidosis more commonly affects the immunocompromised and adults. Melioidosis is increasingly being diagnosed around the world and whole-genome sequencing indicates that these cases are not linked with travel to endemic areas. Research has concentrated on the adult population with limited experience reported in the care of this uncommon, but potentially fatal condition in children presenting with bacteraemia and pneumonia.
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Affiliation(s)
- Olivia Jarrett
- Department of Respiratory Medicine, The Children's Hospital at Westmead, Sydney, NSW 2145, Australia.
| | - Soputhirith Seng
- Department of Respiratory and Allergology, National Pediatric Hospital, Cambodia
| | - Dominic A Fitzgerald
- Department of Respiratory Medicine, The Children's Hospital at Westmead, Sydney, NSW 2145, Australia; Discipline of Child and Adolescent Health, Sydney Medical School, Faculty of Health Sciences, University of Sydney, NSW, Australia
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LeChevallier MW, Prosser T, Stevens M. Opportunistic Pathogens in Drinking Water Distribution Systems-A Review. Microorganisms 2024; 12:916. [PMID: 38792751 PMCID: PMC11124194 DOI: 10.3390/microorganisms12050916] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/01/2024] [Revised: 04/24/2024] [Accepted: 04/25/2024] [Indexed: 05/26/2024] Open
Abstract
In contrast to "frank" pathogens, like Salmonella entrocolitica, Shigella dysenteriae, and Vibrio cholerae, that always have a probability of disease, "opportunistic" pathogens are organisms that cause an infectious disease in a host with a weakened immune system and rarely in a healthy host. Historically, drinking water treatment has focused on control of frank pathogens, particularly those from human or animal sources (like Giardia lamblia, Cryptosporidium parvum, or Hepatitis A virus), but in recent years outbreaks from drinking water have increasingly been due to opportunistic pathogens. Characteristics of opportunistic pathogens that make them problematic for water treatment include: (1) they are normally present in aquatic environments, (2) they grow in biofilms that protect the bacteria from disinfectants, and (3) under appropriate conditions in drinking water systems (e.g., warm water, stagnation, low disinfectant levels, etc.), these bacteria can amplify to levels that can pose a public health risk. The three most common opportunistic pathogens in drinking water systems are Legionella pneumophila, Mycobacterium avium, and Pseudomonas aeruginosa. This report focuses on these organisms to provide information on their public health risk, occurrence in drinking water systems, susceptibility to various disinfectants, and other operational practices (like flushing and cleaning of pipes and storage tanks). In addition, information is provided on a group of nine other opportunistic pathogens that are less commonly found in drinking water systems, including Aeromonas hydrophila, Klebsiella pneumoniae, Serratia marcescens, Burkholderia pseudomallei, Acinetobacter baumannii, Stenotrophomonas maltophilia, Arcobacter butzleri, and several free-living amoebae including Naegleria fowleri and species of Acanthamoeba. The public health risk for these microbes in drinking water is still unclear, but in most cases, efforts to manage Legionella, mycobacteria, and Pseudomonas risks will also be effective for these other opportunistic pathogens. The approach to managing opportunistic pathogens in drinking water supplies focuses on controlling the growth of these organisms. Many of these microbes are normal inhabitants in biofilms in water, so the attention is less on eliminating these organisms from entering the system and more on managing their occurrence and concentrations in the pipe network. With anticipated warming trends associated with climate change, the factors that drive the growth of opportunistic pathogens in drinking water systems will likely increase. It is important, therefore, to evaluate treatment barriers and management activities for control of opportunistic pathogen risks. Controls for primary treatment, particularly for turbidity management and disinfection, should be reviewed to ensure adequacy for opportunistic pathogen control. However, the major focus for the utility's opportunistic pathogen risk reduction plan is the management of biological activity and biofilms in the distribution system. Factors that influence the growth of microbes (primarily in biofilms) in the distribution system include, temperature, disinfectant type and concentration, nutrient levels (measured as AOC or BDOC), stagnation, flushing of pipes and cleaning of storage tank sediments, and corrosion control. Pressure management and distribution system integrity are also important to the microbial quality of water but are related more to the intrusion of contaminants into the distribution system rather than directly related to microbial growth. Summarizing the identified risk from drinking water, the availability and quality of disinfection data for treatment, and guidelines or standards for control showed that adequate information is best available for management of L. pneumophila. For L. pneumophila, the risk for this organism has been clearly established from drinking water, cases have increased worldwide, and it is one of the most identified causes of drinking water outbreaks. Water management best practices (e.g., maintenance of a disinfectant residual throughout the distribution system, flushing and cleaning of sediments in pipelines and storage tanks, among others) have been shown to be effective for control of L. pneumophila in water supplies. In addition, there are well documented management guidelines available for the control of the organism in drinking water distribution systems. By comparison, management of risks for Mycobacteria from water are less clear than for L. pneumophila. Treatment of M. avium is difficult due to its resistance to disinfection, the tendency to form clumps, and attachment to surfaces in biofilms. Additionally, there are no guidelines for management of M. avium in drinking water, and one risk assessment study suggested a low risk of infection. The role of tap water in the transmission of the other opportunistic pathogens is less clear and, in many cases, actions to manage L. pneumophila (e.g., maintenance of a disinfectant residual, flushing, cleaning of storage tanks, etc.) will also be beneficial in helping to manage these organisms as well.
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Affiliation(s)
| | - Toby Prosser
- Melbourne Water, Melbourne, VIC 3001, Australia; (T.P.); (M.S.)
| | - Melita Stevens
- Melbourne Water, Melbourne, VIC 3001, Australia; (T.P.); (M.S.)
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Kain MJW, Reece NL, Parry CM, Rajahram GS, Paterson DL, Woolley SD. The Rapid Emergence of Hypervirulent Klebsiella Species and Burkholderia pseudomallei as Major Health Threats in Southeast Asia: The Urgent Need for Recognition as Neglected Tropical Diseases. Trop Med Infect Dis 2024; 9:80. [PMID: 38668541 PMCID: PMC11054678 DOI: 10.3390/tropicalmed9040080] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/27/2024] [Revised: 03/29/2024] [Accepted: 04/05/2024] [Indexed: 04/29/2024] Open
Abstract
The World Health Organization (WHO)'s list of neglected tropical diseases (NTDs) highlights conditions that are responsible for devastating health, social and economic consequences, and yet, they are overlooked and poorly resourced. The NTD list does not include conditions caused by Gram-negative bacilli (GNB). Infections due to GNB cause significant morbidity and mortality and are prevalent worldwide. Southeast Asia is a WHO region of low- and middle-income countries carrying the largest burden of NTDs. Two significant health threats in Southeast Asia are Burkholderia pseudomallei (causing melioidosis) and hypervirulent Klebsiella pneumoniae (HvKp). Both diseases have high mortality and increasing prevalence, yet both suffer from a lack of awareness, significant under-resourcing, incomplete epidemiological data, limited diagnostics, and a lack of evidence-based treatment. Emerging evidence shows that both melioidosis and HvKp are spreading globally, including in high-income countries, highlighting the potential future global threat they pose. In this article, we review both conditions, identifying current trends and challenges in Southeast Asia and areas for future research. We also argue that melioidosis and HvKp merit inclusion as NTDs, and that mandatory global surveillance and reporting systems should be established, and we make an urgent call for research to better understand, detect, and treat these neglected diseases.
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Affiliation(s)
| | | | - Christopher M. Parry
- Department of Clinical Sciences, Liverpool School of Tropical Medicine, Liverpool L3 5QA, UK;
- Centre for Tropical Medicine and Global Health, Nuffield Department of Clinical Medicine, University of Oxford, Oxford OX1 2JD, UK
| | - Giri Shan Rajahram
- Department of Medicine, Queen Elizabeth II Hospital, Kota Kinabalu 88300, Malaysia
- Infectious Diseases Society, Kota Kinabalu Sabah-Menzies School of Health Research, Clinical Research Unit, Kota Kinabalu 88994, Malaysia
| | - David L. Paterson
- ADVANCE-ID Network, Saw Swee Hock School of Public Health, National University of Singapore, Singapore 119077, Singapore
- Infectious Diseases Translational Research Programme, Yong Loo Lin School of Medicine, National University of Singapore, Singapore 119077, Singapore
| | - Stephen D. Woolley
- Institute of Naval Medicine, Alverstoke, Hampshire PO12 2DL, UK
- Department of Clinical Sciences, Liverpool School of Tropical Medicine, Liverpool L3 5QA, UK;
- Tropical and Infectious Diseases Unit, Liverpool University Hospitals Foundation NHS Trust, Liverpool L7 8YE, UK
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Weeratunga MP, Mayo M, Kaestli M, Currie BJ. Melioidosis Knowledge Awareness in Three Distinct Groups in the Tropical Northern Territory of Australia. Trop Med Infect Dis 2024; 9:71. [PMID: 38668532 PMCID: PMC11054246 DOI: 10.3390/tropicalmed9040071] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/05/2024] [Revised: 03/24/2024] [Accepted: 03/25/2024] [Indexed: 04/29/2024] Open
Abstract
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.
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Affiliation(s)
- Madusha P. Weeratunga
- Menzies School of Health Research, Charles Darwin University, Darwin, NT 0811, Australia; (M.P.W.); (M.M.); (M.K.)
- Infectious Diseases Department, Royal Darwin Hospital, Darwin, NT 0810, Australia
- Northern Territory Medical Program, Flinders and Charles Darwin University, Darwin, NT 0810, Australia
| | - Mark Mayo
- Menzies School of Health Research, Charles Darwin University, Darwin, NT 0811, Australia; (M.P.W.); (M.M.); (M.K.)
| | - Mirjam Kaestli
- Menzies School of Health Research, Charles Darwin University, Darwin, NT 0811, Australia; (M.P.W.); (M.M.); (M.K.)
| | - Bart J. Currie
- Menzies School of Health Research, Charles Darwin University, Darwin, NT 0811, Australia; (M.P.W.); (M.M.); (M.K.)
- Infectious Diseases Department, Royal Darwin Hospital, Darwin, NT 0810, Australia
- Northern Territory Medical Program, Flinders and Charles Darwin University, Darwin, NT 0810, Australia
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Baker K, Smith S, Stewart J, Withey G, Bain M, Pridgeon S, Hanson J. Melioidosis of the Female Genitourinary Tract. Am J Trop Med Hyg 2023; 109:1233-1237. [PMID: 37955316 DOI: 10.4269/ajtmh.23-0350] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/28/2023] [Accepted: 09/08/2023] [Indexed: 11/14/2023] Open
Abstract
Prostatic abscess is a common manifestation of melioidosis in men, but the characteristics of female genitourinary melioidosis are incompletely defined. There were 453 cases of melioidosis in Far North Queensland, tropical Australia, between January 1998 and April 2023; genitourinary involvement was less common in women than in men (13/140 [9%] versus 76/313 [24%], odds ratio [95% confidence interval]: 0.32 [0.17-0.60], P = 0.0004). In 11 of these 13 (85%) women, other organs were also affected. The two women with disease involving only the genitourinary tract had underlying anatomical abnormalities: one had an ovarian malignancy, the only case to involve the female reproductive system in the cohort, while the other had a urethral diverticulum. In 3 of 13 (23%) women, genitourinary involvement was identified only with computed tomography, emphasizing the importance of early imaging of patients with melioidosis to identify unexpected foci of disease and to inform the optimal duration of antibiotic therapy.
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Affiliation(s)
- Kelly Baker
- Department of Medicine, Cairns Hospital, Cairns, Australia
| | - Simon Smith
- Department of Medicine, Cairns Hospital, Cairns, Australia
| | - James Stewart
- Department of Medicine, Cairns Hospital, Cairns, Australia
| | - Grant Withey
- Department of Radiology, Cairns Hospital, Cairns, Australia
| | - Madeleine Bain
- Department of Surgery, Cairns Hospital, Cairns, Australia
| | - Simon Pridgeon
- Department of Surgery, Cairns Hospital, Cairns, Australia
| | - Josh Hanson
- Department of Medicine, Cairns Hospital, Cairns, Australia
- The Kirby Institute, University of New South Wales, Sydney, Australia
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Smith S, Marquardt T, Jennison AV, D'Addona A, Stewart J, Yarwood T, Ho J, Binotto E, Harris J, Fahmy M, Esmonde J, Richardson M, Graham RMA, Gair R, Ariotti L, Preston-Thomas A, Rubenach S, O'Sullivan S, Allen D, Ragh T, Grayson S, Manoy S, Warner JM, Meumann EM, Robson JM, Hanson J. Clinical Manifestations and Genomic Evaluation of Melioidosis Outbreak among Children after Sporting Event, Australia. Emerg Infect Dis 2023; 29:2218-2228. [PMID: 37877500 PMCID: PMC10617349 DOI: 10.3201/eid2911.230951] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/26/2023] Open
Abstract
Melioidosis, caused by the environmental gram-negative bacterium Burkholderia pseudomallei, usually develops in adults with predisposing conditions and in Australia more commonly occurs during the monsoonal wet season. We report an outbreak of 7 cases of melioidosis in immunocompetent children in Australia. All the children had participated in a single-day sporting event during the dry season in a tropical region of Australia, and all had limited cutaneous disease. All case-patients had an adverse reaction to oral trimethoprim/sulfamethoxazole treatment, necessitating its discontinuation. We describe the clinical features, environmental sampling, genomic epidemiologic investigation, and public health response to the outbreak. Management of this outbreak shows the potential benefits of making melioidosis a notifiable disease. The approach used could also be used as a framework for similar outbreaks in the future.
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Prinsloo C, Smith S, Law M, Hanson J. The Epidemiological, Clinical, and Microbiological Features of Patients with Burkholderia pseudomallei Bacteraemia-Implications for Clinical Management. Trop Med Infect Dis 2023; 8:481. [PMID: 37999600 PMCID: PMC10675116 DOI: 10.3390/tropicalmed8110481] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/20/2023] [Revised: 10/21/2023] [Accepted: 10/23/2023] [Indexed: 11/25/2023] Open
Abstract
Patients with melioidosis are commonly bacteraemic. However, the epidemiological characteristics, the microbiological findings, and the clinical associations of Burkholderia pseudomallei bacteraemia are incompletely defined. All cases of culture-confirmed melioidosis at Cairns Hospital in tropical Australia between January 1998 and June 2023 were reviewed. The presence of bacteraemia was determined and correlated with patient characteristics and outcomes; 332/477 (70%) individuals in the cohort were bacteraemic. In multivariable analysis, immunosuppression (odds ratio (OR) (95% confidence interval (CI)): (2.76 (1.21-6.27), p = 0.02), a wet season presentation (2.27 (1.44-3.59), p < 0.0001) and male sex (1.69 (1.08-2.63), p = 0.02), increased the likelihood of bacteraemia. Patients with a skin or soft tissue infection (0.32 (0.19-0.57), p < 0.0001) or without predisposing factors for melioidosis (0.53 (0.30-0.93), p = 0.03) were less likely to be bacteraemic. Bacteraemia was associated with intensive care unit admission (OR (95%CI): 4.27 (2.35-7.76), p < 0.0001), and death (2.12 (1.04-4.33), p = 0.04). The median (interquartile range) time to blood culture positivity was 31 (26-39) hours. Patients with positive blood cultures within 24 h were more likely to die than patients whose blood culture flagged positive after this time (OR (95%CI): 11.05 (3.96-30.83), p < 0.0001). Bacteraemia portends a worse outcome in patients with melioidosis. Its presence or absence might be used to help predict outcomes in cases of melioidosis and to inform optimal clinical management.
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Affiliation(s)
- Carmen Prinsloo
- College of Medicine and Dentistry, James Cook University, Cairns Hospital, Cairns, QLD 4870, Australia
| | - Simon Smith
- Department of Medicine, Cairns Hospital, Cairns, QLD 4870, Australia;
| | - Matthew Law
- The Kirby Institute, University of New South Wales, Sydney, NSW 2042, Australia;
| | - Josh Hanson
- Department of Medicine, Cairns Hospital, Cairns, QLD 4870, Australia;
- The Kirby Institute, University of New South Wales, Sydney, NSW 2042, Australia;
- Global and Tropical Health Division, Menzies School of Health Research, Charles Darwin University, Darwin, NT 0811, Australia
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Jitprasutwit N, Rungruengkitkun A, Lohitthai S, Reamtong O, Indrawattana N, Sookrung N, Sricharunrat T, Sukphopetch P, Chatratita N, Pumirat P. In Vitro Roles of Burkholderia Intracellular Motility A (BimA) in Infection of Human Neuroblastoma Cell Line. Microbiol Spectr 2023; 11:e0132023. [PMID: 37409935 PMCID: PMC10434047 DOI: 10.1128/spectrum.01320-23] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/28/2023] [Accepted: 06/16/2023] [Indexed: 07/07/2023] Open
Abstract
The bacterial pathogen Burkholderia pseudomallei causes human melioidosis, which can infect the brain, leading to encephalitis and brain abscesses. Infection of the nervous system is a rare condition but is associated with an increased risk of mortality. Burkholderia intracellular motility A (BimA) was reported to play an important role in the invasion and infection of the central nervous system in a mouse model. Thus, to gain insight of the cellular mechanisms underlying the pathogenesis of neurological melioidosis, we explored the human neuronal proteomics to identify the host factors that are up- and downregulated during Burkholderia infection. When infected the SH-SY5Y cells with B. pseudomallei K96243 wild-type (WT), 194 host proteins showed a fold change of >2 compared with uninfected cells. Moreover, 123 proteins showed a fold change of >2 when infected with a knockout bimA mutant (ΔbimA) mutant compared with WT. The differentially expressed proteins were mainly associated with metabolic pathways and pathways linked to human diseases. Importantly, we observed the downregulation of proteins in the apoptosis and cytotoxicity pathway, and in vitro investigation with the ΔbimA mutant revealed the association of BimA with the induction of these pathways. Additionally, we disclosed that BimA was not required for invasion into the neuron cell line but was necessary for effective intracellular replication and multinucleated giant cell (MNGC) formation. These findings show the extraordinary capacity of B. pseudomallei in subverting and interfering with host cellular systems to establish infection and extend our understanding of B. pseudomallei BimA involvement in the pathogenesis of neurological melioidosis. IMPORTANCE Neurological melioidosis, caused by Burkholderia pseudomallei, can result in severe neurological damage and enhance the mortality rate of melioidosis patients. We investigate the involvement of the virulent factor BimA, which mediates actin-based motility, in the intracellular infection of neuroblastoma SH-SY5Y cells. Using proteomics-based analysis, we provide a list of host factors exploited by B. pseudomallei. The expression level of selected downregulated proteins in neuron cells infected with the ΔbimA mutant was determined by quantitative reverse transcription-PCR and was consistent with our proteomic data. The role of BimA in the apoptosis and cytotoxicity of SH-SY5Y cells infected by B. pseudomallei was uncovered in this study. Additionally, our research demonstrates that BimA is required for successful intracellular survival and cell fusion upon infection of neuron cells. Our findings have significant implications for understanding the pathogenesis of B. pseudomallei infections and developing novel therapeutic strategies to combat this deadly disease.
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Affiliation(s)
- Niramol Jitprasutwit
- Center for Vaccine Development, Institute of Molecular Biosciences, Mahidol University, Nakhon Pathom, Thailand
| | - Amporn Rungruengkitkun
- Department of Microbiology and Immunology, Faculty of Tropical Medicine, Mahidol University, Bangkok, Thailand
| | - Sanisa Lohitthai
- Department of Microbiology and Immunology, Faculty of Tropical Medicine, Mahidol University, Bangkok, Thailand
| | - Onrapak Reamtong
- Department of Molecular Tropical Medicine and Genetics, Faculty of Tropical Medicine, Mahidol University, Bangkok, Thailand
| | - Nitaya Indrawattana
- Department of Microbiology and Immunology, Faculty of Tropical Medicine, Mahidol University, Bangkok, Thailand
| | - Nitat Sookrung
- Center of Research Excellence on Therapeutic Proteins and Antibody Engineering, Department of Parasitology, Faculty of Medicine Siriraj Hospital, Mahidol University, Bangkok, Thailand
- Biomedical Research Incubator Unit, Department of Research, Faculty of Medicine Siriraj Hospital, Mahidol University, Bangkok, Thailand
| | - Thaniya Sricharunrat
- Pathology and Forensic Science Department, Chulabhorn Hospital, Chulabhorn Royal Academy, Bangkok, Thailand
| | - Passanesh Sukphopetch
- Department of Microbiology and Immunology, Faculty of Tropical Medicine, Mahidol University, Bangkok, Thailand
| | - Narisara Chatratita
- Department of Microbiology and Immunology, Faculty of Tropical Medicine, Mahidol University, Bangkok, Thailand
- Mahidol-Oxford Tropical Medicine Research Unit, Faculty of Tropical Medicine, Mahidol University, Bangkok, Thailand
| | - Pornpan Pumirat
- Department of Microbiology and Immunology, Faculty of Tropical Medicine, Mahidol University, Bangkok, Thailand
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Gassiep I, Grey V, Thean LJ, Farquhar D, Clark JE, Ariotti L, Graham R, Jennison AV, Bergh H, Anuradha S, Dyer W, James C, Huang A, Putt E, Pakeerathan V, Griffin PM, Harris PNA. Expanding the Geographic Boundaries of Melioidosis in Queensland, Australia. Am J Trop Med Hyg 2023; 108:1215-1219. [PMID: 37160276 PMCID: PMC10540097 DOI: 10.4269/ajtmh.23-0002] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/01/2023] [Accepted: 03/23/2023] [Indexed: 05/11/2023] Open
Abstract
Melioidosis is an infectious disease caused by the bacterium Burkholderia pseudomallei. Although this environmental organism is endemic in certain regions of Australia, it is not considered endemic in Southern Queensland, where the last case was reported 21 years ago. We report a climate change-associated outbreak of melioidosis occurring during two La Niña events in a region previously considered nonendemic for B. pseudomallei. During a 15-month period, 14 cases of locally acquired melioidosis were identified. Twelve patients were adults (> 50 years), with diabetes mellitus the most common risk factor in 6 of 12 patients (50%). Eleven patients (79%) had direct exposure to floodwaters or the flooded environment. This study suggests an association between climate change and an increased incidence of melioidosis. In addition, this is the first report of environmental sampling and whole-genome analysis to prove endemicity and local acquisition in this region.
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Affiliation(s)
- Ian Gassiep
- University of Queensland Centre for Clinical Research, Royal Brisbane and Woman’s Hospital, Herston, Queensland, Australia
- Mater Hospital Brisbane, South Brisbane, Queensland, Australia
- Pathology Queensland, Royal Brisbane and Women’s Hospital, Brisbane, Queensland, Australia
| | - Victoria Grey
- Mater Hospital Brisbane, South Brisbane, Queensland, Australia
| | - Li Jun Thean
- Queensland Children’s Hospital, South Brisbane, Queensland, Australia
| | - Drew Farquhar
- Sunshine Coast University Hospital, Birtinya, Queensland, Australia
| | - Julia E. Clark
- Queensland Children’s Hospital, South Brisbane, Queensland, Australia
| | - Lawrence Ariotti
- Public Health Microbiology, Forensic and Scientific Services, Queensland Health, Brisbane, Queensland, Australia
| | - Rikki Graham
- Public Health Microbiology, Forensic and Scientific Services, Queensland Health, Brisbane, Queensland, Australia
| | - Amy V. Jennison
- Public Health Microbiology, Forensic and Scientific Services, Queensland Health, Brisbane, Queensland, Australia
| | - Haakon Bergh
- Pathology Queensland, Royal Brisbane and Women’s Hospital, Brisbane, Queensland, Australia
| | | | - Wendy Dyer
- Metro South Public Health Unit, Brisbane, Queensland, Australia
| | - Christian James
- Metro South Public Health Unit, Brisbane, Queensland, Australia
| | - Andrea Huang
- Bundaberg Hospital, Bundaberg, Queensland, Australia
| | - Elise Putt
- Bundaberg Hospital, Bundaberg, Queensland, Australia
| | | | - Paul M. Griffin
- Mater Hospital Brisbane, South Brisbane, Queensland, Australia
- Faculty of Medicine, University of Queensland, Brisbane, Queensland, Australia
| | - Patrick N. A. Harris
- University of Queensland Centre for Clinical Research, Royal Brisbane and Woman’s Hospital, Herston, Queensland, Australia
- Pathology Queensland, Royal Brisbane and Women’s Hospital, Brisbane, Queensland, Australia
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12
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Matthews RJ, Smith S, Wilson I, Tjahjono R, Young S, Hanson J. Case Report: Vagal Nerve Neuritis Associated with Pulmonary Melioidosis Provides Potential Insights into the Pathophysiology of Neuromelioidosis. Am J Trop Med Hyg 2023; 108:1212-1214. [PMID: 37188337 PMCID: PMC10540098 DOI: 10.4269/ajtmh.22-0694] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/05/2022] [Accepted: 03/07/2023] [Indexed: 05/17/2023] Open
Abstract
Encephalomyelitis is the most frequent manifestation of neuromelioidosis in Australia. It is hypothesized that Burkholderia pseudomallei causes encephalomyelitis after entering the brain directly, if complicating a scalp infection, or after traveling to the brain within peripheral or cranial nerves. A 76-year-old man presented with fever, dysphonia, and hiccups. Chest imaging demonstrated extensive bilateral pneumonia with mediastinal lymphadenopathy, blood cultures isolated B. pseudomallei, and nasendoscopy confirmed a left vocal cord palsy. Magnetic resonance imaging identified no intracranial abnormality but demonstrated an enlarged, enhancing left vagus nerve, consistent with neuritis. We hypothesize that B. pseudomallei invaded the vagus nerve in the thorax, was traveling proximally-involving the left recurrent laryngeal nerve and causing the left vocal cord palsy, but had not yet reached the brainstem. Given the frequency of pneumonia in cases of melioidosis, the vagus nerve may represent an alternative, and indeed common, route for B. pseudomallei to enter the brainstem in cases of melioidosis-related encephalomyelitis.
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Affiliation(s)
| | - Simon Smith
- Department of Medicine, Cairns Hospital, Cairns, Australia
| | - Ian Wilson
- Department of Medicine, Cairns Hospital, Cairns, Australia
| | - Richard Tjahjono
- Department of Surgery, Cairns Hospital, Cairns, Australia
- Sydney Medical School, University of Sydney, Sydney, Australia
| | - Soon Young
- Department of Radiology, Cairns Hospital, Cairns, Australia
| | - Josh Hanson
- Department of Medicine, Cairns Hospital, Cairns, Australia
- The Kirby Institute, University of New South Wales, Sydney, Australia
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13
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Smith S, Buikstra E, Rubenach S, Preston-Thomas A, Hanson J. Limited Awareness of Melioidosis in High-risk Populations Despite an Increasing Incidence of the Disease in Far North Queensland, Australia. Am J Trop Med Hyg 2022; 107:1278-1280. [PMID: 35895342 PMCID: PMC9768265 DOI: 10.4269/ajtmh.22-0160] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/27/2022] [Accepted: 05/17/2022] [Indexed: 12/30/2022] Open
Abstract
The incidence of melioidosis, an opportunistic infection caused by Burkholderia pseudomallei, has recently doubled in Far North Queensland (FNQ), Australia. This contrasts with the local burden of dengue, which is nearing elimination, and the stable incidence of leptospirosis. This questionnaire-based study assessed the awareness of melioidosis among people in FNQ with risk factors for the disease, using awareness of leptospirosis and dengue as comparators. There were 427 respondents; 361 (85%) reported one or more risk factors for melioidosis. Only 69 of 361 (19%) had heard of melioidosis compared with 301 of 361 (83%) who had heard of dengue (P < 0.001) and 137 of 361 (38%) who had heard of leptospirosis (P < 0.001). In FNQ, Australia, there is an increasing local incidence of melioidosis, but there is limited awareness of the disease among high-risk individuals. Greater community awareness of melioidosis is necessary to implement strategies to prevent disease and expedite the presentation of patients with this life-threatening infection.
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Affiliation(s)
- Simon Smith
- Department of Medicine, Cairns Hospital, Cairns, Queensland, Australia
| | | | - Sally Rubenach
- Tropical Public Health Services, Cairns, Queensland, Australia
| | | | - Josh Hanson
- Department of Medicine, Cairns Hospital, Cairns, Queensland, Australia
- The Kirby Institute, New South Wales, Australia
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14
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Harris J, Smith S, Ng SZ, Sinha A, Hanson J. Case Report: Disseminated Burkholderia pseudomallei with Acute Suppurative Thyroiditis and Abscess Formation. Am J Trop Med Hyg 2022; 107:tpmd220277. [PMID: 35914690 PMCID: PMC9490665 DOI: 10.4269/ajtmh.22-0277] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/22/2022] [Accepted: 05/20/2022] [Indexed: 11/07/2022] Open
Abstract
Melioidosis has a highly variable presentation. Almost any organ can be involved, although an antemortem diagnosis of acute suppurative thyroiditis (AST) has not, to our knowledge, been previously described. A 68-year-old Australian male with poorly controlled type 2 diabetes mellitus presented with fever, odynophagia, and thyroid function tests consistent with hyperthyroidism. Imaging demonstrated a lung abscess and an enlarged thyroid gland with three nodules. Blood cultures and fine-needle aspiration of the thyroid nodules grew Burkholderia pseudomallei. He received intravenous ceftazidime and concurrent oral trimethoprim/sulfamethoxazole (TMP/SMX) for 4 weeks followed by high-dose oral TMP/SMX for a further 3 months and made a complete recovery. Acute suppurative thyroiditis is an uncommon cause of hyperthyroidism and thyroid aspirates are not commonly sent for bacterial culture. The case highlights the need to consider AST in patients presenting with a hyperthyroid state and disseminated infection. It also demonstrates that in a case of disseminated melioidosis any symptom may be a clue to underlying metastatic infection.
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Affiliation(s)
| | - Simon Smith
- Cairns Hospital, Cairns, Queensland, Australia
| | | | - Ashim Sinha
- Cairns Hospital, Cairns, Queensland, Australia
- James Cook University, Cairns, Queensland, Australia
| | - Josh Hanson
- Cairns Hospital, Cairns, Queensland, Australia
- The Kirby Institute, University of New South Wales, Sydney, New South Wales, Australia
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15
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Shaw T, Assig K, Tellapragada C, Wagner GE, Choudhary M, Göhler A, Eshwara VK, Steinmetz I, Mukhopadhyay C. Environmental Factors Associated With Soil Prevalence of the Melioidosis Pathogen Burkholderia pseudomallei: A Longitudinal Seasonal Study From South West India. Front Microbiol 2022; 13:902996. [PMID: 35847064 PMCID: PMC9283100 DOI: 10.3389/fmicb.2022.902996] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/23/2022] [Accepted: 06/07/2022] [Indexed: 11/13/2022] Open
Abstract
Melioidosis is a seasonal infectious disease in tropical and subtropical areas caused by the soil bacterium Burkholderia pseudomallei. In many parts of the world, including South West India, most cases of human infections are reported during times of heavy rainfall, but the underlying causes of this phenomenon are not fully understood. India is among the countries with the highest predicted melioidosis burden globally, but there is very little information on the environmental distribution of B. pseudomallei and its determining factors. The present study aimed (i) to investigate the prevalence of B. pseudomallei in soil in South West India, (ii) determine geochemical factors associated with B. pseudomallei presence and (iii) look for potential seasonal patterns of B. pseudomallei soil abundance. Environmental samplings were performed in two regions during the monsoon and post-monsoon season and summer from July 2016 to November 2018. We applied direct quantitative real time PCR (qPCR) together with culture protocols to overcome the insufficient sensitivity of solely culture-based B. pseudomallei detection from soil. A total of 1,704 soil samples from 20 different agricultural sites were screened for the presence of B. pseudomallei. Direct qPCR detected B. pseudomallei in all 20 sites and in 30.2% (517/1,704) of all soil samples, whereas only two samples from two sites were culture-positive. B. pseudomallei DNA-positive samples were negatively associated with the concentration of iron, manganese and nitrogen in a binomial logistic regression model. The highest number of B. pseudomallei-positive samples (42.6%, p < 0.0001) and the highest B. pseudomallei loads in positive samples [median 4.45 × 103 genome equivalents (GE)/g, p < 0.0001] were observed during the monsoon season and eventually declined to 18.9% and a median of 1.47 × 103 GE/g in summer. In conclusion, our study from South West India shows a wide environmental distribution of B. pseudomallei, but also considerable differences in the abundance between sites and within single sites. Our results support the hypothesis that nutrient-depleted habitats promote the presence of B. pseudomallei. Most importantly, the highest B. pseudomallei abundance in soil is seen during the rainy season, when melioidosis cases occur.
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Affiliation(s)
- Tushar Shaw
- Department of Microbiology, Kasturba Medical College, Manipal Academy of Higher Education, Manipal, India
- Faculty of Life and Allied Health Sciences, Ramaiah University of Applied Sciences, Bengaluru, India
| | - Karoline Assig
- Diagnostic and Research Institute of Hygiene, Microbiology and Environmental Medicine, Medical University of Graz, Graz, Austria
- Friedrich Loeffler Institute of Medical Microbiology, University Medicine Greifswald, Greifswald, Germany
| | - Chaitanya Tellapragada
- Department of Microbiology, Kasturba Medical College, Manipal Academy of Higher Education, Manipal, India
- Division of Clinical Microbiology, Department of Laboratory Medicine, Karolinska Institutet, Stockholm, Sweden
| | - Gabriel E. Wagner
- Diagnostic and Research Institute of Hygiene, Microbiology and Environmental Medicine, Medical University of Graz, Graz, Austria
| | - Madhu Choudhary
- ICAR-Central Soil Salinity Research Institute (CSSRI), Karnal, India
| | - André Göhler
- German Federal Institute for Risk Assessment, Berlin, Germany
| | - Vandana Kalwaje Eshwara
- Department of Microbiology, Kasturba Medical College, Manipal Academy of Higher Education, Manipal, India
- Centre for Antimicrobial Resistance and Education, Manipal Academy of Higher Education, Manipal, India
| | - Ivo Steinmetz
- Diagnostic and Research Institute of Hygiene, Microbiology and Environmental Medicine, Medical University of Graz, Graz, Austria
- Friedrich Loeffler Institute of Medical Microbiology, University Medicine Greifswald, Greifswald, Germany
- *Correspondence: Ivo Steinmetz,
| | - Chiranjay Mukhopadhyay
- Department of Microbiology, Kasturba Medical College, Manipal Academy of Higher Education, Manipal, India
- Centre for Emerging and Tropical Diseases, Manipal Academy of Higher Education, Manipal, India
- Chiranjay Mukhopadhyay,
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16
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Clinical Burkholderia pseudomallei isolates from north Queensland carry diverse bimABm genes that are associated with central nervous system disease and are phylogenomically distinct from other Australian strains. PLoS Negl Trop Dis 2022; 16:e0009482. [PMID: 35700198 PMCID: PMC9236262 DOI: 10.1371/journal.pntd.0009482] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/25/2021] [Revised: 06/27/2022] [Accepted: 05/24/2022] [Indexed: 11/19/2022] Open
Abstract
Background Burkholderia pseudomallei is an environmental gram-negative bacterium that causes the disease melioidosis and is endemic in many countries of the Asia-Pacific region. In Australia, the mortality rate remains high at approximately 10%, despite curative antibiotic treatment being available. The bacterium is almost exclusively found in the endemic region, which spans the tropical Northern Territory and North Queensland, with clusters occasionally present in more temperate climates. Despite being endemic to North Queensland, these infections remain understudied compared to those of the Northern Territory. Methodology/Principal findings This study aimed to assess the prevalence of central nervous system (CNS) disease associated variant bimABm, identify circulating antimicrobial resistance mutations and genetically distinct strains from Queensland, via comparative genomics. From 76 clinical isolates, we identified the bimABm variant in 20 (26.3%) isolates and in 9 (45%) of the isolates with documented CNS infection (n = 18). Explorative analysis suggests a significant association between isolates carrying the bimABm variant and CNS disease (OR 2.8, 95% CI 1.3–6.0, P = 0.009) compared with isolates carrying the wildtype bimABp. Furthermore, 50% of isolates were identified as novel multi-locus sequence types, while the bimABm variant was more commonly identified in isolates with novel sequence types, compared to those with previously described. Additionally, mutations associated with acquired antimicrobial resistance were only identified in 14.5% of all genomes. Conclusions/Significance The findings of this research have provided clinically relevant genomic data of B. pseudomallei in Queensland and suggest that the bimABm variant may enable risk stratification for the development CNS complications and be a potential therapeutic target. Melioidosis is a life-threatening infection, caused by the Gram-negative bacterium Burkholderia pseudomallei, which is endemic to tropical regions in Australia. Variants of the bimA gene have been proposed as a virulence factor associated with more severe disease. In a genomic analysis of 76 clinical B. pseudomallei isolates from Queensland, Australia, we identified that the bimABm variant was associated with infection involving the central nervous system (odds ratio 2.8, 95% Confidence Interval: 1.3–6.0, P = 0.009), compared to isolates with the wild-type allele bimABp. Half of the isolates from this region were novel multi-locus sequence types, and bimABm was more commonly seen in these novel sequence types. Early genomic characterisation to identify virulence factors such as bimABm, may be useful as an early marker of more complex disease that could guide further investigation and help determine optimal treatment. Further investigation of a “genomics-guided” approach to the clinical management of this complex infectious disease are warranted.
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Sanchez-Villamil JI, Tapia D, Khakhum N, Widen SG, Torres AG. Dual RNA-seq reveals a type 6 secretion system-dependent blockage of TNF-α signaling and BicA as a Burkholderia pseudomallei virulence factor important during gastrointestinal infection. Gut Microbes 2022; 14:2111950. [PMID: 35984745 PMCID: PMC9397134 DOI: 10.1080/19490976.2022.2111950] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 05/18/2022] [Accepted: 08/03/2022] [Indexed: 02/04/2023] Open
Abstract
Melioidosis is a disease caused by the Gram-negative bacillus Burkholderia pseudomallei (Bpm), commonly found in soil and water of endemic areas. Naturally acquired human melioidosis infections can result from either exposure through percutaneous inoculation, inhalation, or ingestion of soil-contaminated food or water. Our prior studies recognized Bpm as an effective enteric pathogen, capable of establishing acute or chronic gastrointestinal infections following oral inoculation. However, the specific mechanisms and virulence factors involved in the pathogenesis of Bpm during intestinal infection are unknown. In our current study, we standardized an in vitro intestinal infection model using primary intestinal epithelial cells (IECs) and demonstrated that Bpm requires a functional T6SS for full virulence. Further, we performed dual RNA-seq analysis on Bpm-infected IECs to evaluate differentially expressed host and bacterial genes in the presence or absence of a T6SS. Our results showed a dysregulation in the TNF-α signaling via NF-κB pathway in the absence of the T6SS, with some of the genes involved in inflammatory processes and cell death also affected. Analysis of the bacterial transcriptome identified virulence factors and regulatory proteins playing a role during infection, with association to the T6SS. By using a Bpm transposon mutant library and isogenic mutants, we showed that deletion of the bicA gene, encoding a putative T3SS/T6SS regulator, ablated intracellular survival and plaque formation by Bpm and impacted survival and virulence when using murine models of acute and chronic gastrointestinal infection. Overall, these results highlight the importance of the type 6 secretion system in the gastrointestinal pathogenesis of Bpm.
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Affiliation(s)
| | - Daniel Tapia
- Department of Microbiology and Immunology, University of Texas Medical Branch, Galveston, Texas, USA
| | - Nittaya Khakhum
- Department of Microbiology and Immunology, University of Texas Medical Branch, Galveston, Texas, USA
| | - Steven G. Widen
- Department of Biochemistry and Molecular Biology, University of Texas Medical Branch, Galveston, Texas, USA
| | - Alfredo G. Torres
- Department of Microbiology and Immunology, University of Texas Medical Branch, Galveston, Texas, USA
- Department of Pathology, University of Texas Medical Branch, Galveston, Texas, USA
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18
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Chieng R. Melioidosis. WIKIJOURNAL OF MEDICINE 2022. [DOI: 10.15347/wjm/2022.004] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
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19
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Salaveria K, Smith S, Liu YH, Bagshaw R, Ott M, Stewart A, Law M, Carter A, Hanson J. The Applicability of Commonly Used Severity of Illness Scores to Tropical Infections in Australia. Am J Trop Med Hyg 2021; 106:257-267. [PMID: 34662860 PMCID: PMC8733535 DOI: 10.4269/ajtmh.21-0615] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/02/2021] [Accepted: 08/31/2021] [Indexed: 01/03/2023] Open
Abstract
Many patients with leptospirosis, melioidosis, and rickettsial infection require intensive care unit (ICU) admission in tropical Australia every year. The multi-organ dysfunction associated with these infections results in significantly elevated severity of illness (SOI) scores. However, the accuracy of these SOI scores in predicting death from these tropical infections is incompletely defined. This retrospective study was performed at Cairns Hospital, a tertiary-referral hospital in tropical Australia. All patients admitted to ICU with laboratory-confirmed leptospirosis, melioidosis, and rickettsial disease between January 1, 1999 and June 30, 2020, were eligible for the study. The ability of Acute Physiology and Chronic Health Evaluation (APACHE) II, APACHE III, Simplified Acute Physiology Scores (SAPS) II, and Sequential Organ Failure Assessment (SOFA) scores to predict death before ICU discharge was evaluated. Overall, 18 (12.1%) of the 149 included patients died: 15/74 (20.3%) with melioidosis, 2/54 (3.7%) with leptospirosis and 1/21 (4.8%) with rickettsial disease. However, the APACHE II, APACHE III, SAPS II, and SOFA scores significantly overestimated the case-fatality rate of all the infections; the disparity between the predicted and observed mortality was most marked in the cases of leptospirosis and rickettsial disease. Commonly used SOI scores significantly overestimate the case-fatality rate of melioidosis, leptospirosis, and rickettsial infections in Australian ICU patients. This may be at least partly explained by the unique pathophysiology of these infections, particularly leptospirosis and rickettsial disease. However, SOI scores may still be useful in facilitating the comparison of disease severity in clinical trials that examine patients with these pathogens.
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Affiliation(s)
- Kris Salaveria
- Department of Intensive Care, Cairns Hospital, Cairns, Queensland, Australia
| | - Simon Smith
- Department of Medicine, Cairns Hospital, Cairns, Queensland, Australia
| | - Yu-Hsuan Liu
- Department of Intensive Care, Cairns Hospital, Cairns, Queensland, Australia
| | - Richard Bagshaw
- Department of Medicine, Cairns Hospital, Cairns, Queensland, Australia
| | - Markus Ott
- Department of Intensive Care, Cairns Hospital, Cairns, Queensland, Australia
| | | | - Matthew Law
- Kirby Institute, University of New South Wales, Sydney, Australia
| | - Angus Carter
- Department of Intensive Care, Cairns Hospital, Cairns, Queensland, Australia
- James Cook University, Cairns Campus, Cairns, Queensland, Australia
| | - Josh Hanson
- Department of Medicine, Cairns Hospital, Cairns, Queensland, Australia
- Kirby Institute, University of New South Wales, Sydney, Australia
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20
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Hanson J, Smith S, Stewart J, Horne P, Ramsamy N. Melioidosis-a disease of socioeconomic disadvantage. PLoS Negl Trop Dis 2021; 15:e0009544. [PMID: 34153059 PMCID: PMC8248627 DOI: 10.1371/journal.pntd.0009544] [Citation(s) in RCA: 23] [Impact Index Per Article: 7.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/07/2021] [Revised: 07/01/2021] [Accepted: 06/07/2021] [Indexed: 12/30/2022] Open
Abstract
BACKGROUND There is growing recognition of the contribution of the social determinants of health to the burden of many infectious diseases. However, the relationship between socioeconomic status and the incidence and outcome of melioidosis is incompletely defined. METHODS All residents of Far North Queensland, tropical Australia with culture-proven melioidosis between January 1998 and December 2020 were eligible for the study. Their demographics, comorbidities and socioeconomic status were correlated with their clinical course. Socioeconomic status was determined using the Socio-Economic Indexes for Areas (SEIFA) Index of Relative Socio-economic Disadvantage score, a measure of socioeconomic disadvantage developed by the Australian Bureau of Statistics. Socioeconomic disadvantage was defined as residence in a region with a SEIFA score in the lowest decile in Australia. RESULTS 321 eligible individuals were diagnosed with melioidosis during the study period, 174 (54.2%) identified as Indigenous Australians; 223/321 (69.5%) were bacteraemic, 85/321 (26.5%) required Intensive Care Unit (ICU) admission and 37/321 (11.5%) died. 156/321 (48.6%) were socioeconomically disadvantaged, compared with 56603/269002 (21.0%) of the local general population (p<0.001). Socioeconomically disadvantaged patients were younger, more likely to be female, Indigenous, diabetic or have renal disease. They were also more likely to die prior to hospital discharge (26/156 (16.7%) versus 11/165 (6.7%), p = 0.002) and to die at a younger age (median (IQR) age: 50 (38-68) versus 65 (59-81) years, p = 0.02). In multivariate analysis that included age, Indigenous status, the presence of bacteraemia, ICU admission and the year of hospitalisation, only socioeconomic disadvantage (odds ratio (OR) (95% confidence interval (CI)): 2.49 (1.16-5.35), p = 0.02) and ICU admission (OR (95% CI): 4.79 (2.33-9.86), p<0.001) were independently associated with death. CONCLUSION Melioidosis is disease of socioeconomic disadvantage. A more holistic approach to the delivery of healthcare which addresses the social determinants of health is necessary to reduce the burden of this life-threatening disease.
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Affiliation(s)
- Josh Hanson
- Kirby Institute, University of New South Wales, Sydney, Australia
- Department of Medicine, Cairns Hospital, Cairns, Queensland, Australia
- * E-mail:
| | - Simon Smith
- Department of Medicine, Cairns Hospital, Cairns, Queensland, Australia
| | - James Stewart
- Department of Medicine, Cairns Hospital, Cairns, Queensland, Australia
| | - Peter Horne
- Tropical Public Health Service, Cairns, Queensland, Australia
| | - Nicole Ramsamy
- Torres and Cape Hospital and Health Service, Cairns, Queensland, Australia
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21
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Burnard D, Robertson G, Henderson A, Falconer C, Bauer MJ, Cottrell K, Gassiep I, Norton R, Paterson DL, Harris PNA. Burkholderia pseudomallei Clinical Isolates Are Highly Susceptible In Vitro to Cefiderocol, a Siderophore Cephalosporin. Antimicrob Agents Chemother 2021; 65:e00685-20. [PMID: 33168603 PMCID: PMC7848980 DOI: 10.1128/aac.00685-20] [Citation(s) in RCA: 9] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/09/2020] [Accepted: 10/22/2020] [Indexed: 12/11/2022] Open
Abstract
Cefiderocol is a cephalosporin designed to treat multidrug-resistant Gram-negative infections. By forming a chelated complex with ferric iron, cefiderocol is transported into the periplasmic space via bacterial iron transport systems and primarily binds to penicillin-binding protein 3 (PBP3) to inhibit peptidoglycan synthesis. This mode of action results in cefiderocol having greater in vitro activity against many Gram-negative bacilli than currently used carbapenems, β-lactam/β-lactamase inhibitor combinations, and cephalosporins. Thus, we investigated the in vitro activity of cefiderocol against a total of 246 clinical isolates of Burkholderia pseudomallei from Queensland, Australia. The collection was composed primarily of bloodstream (56.1%), skin and soft tissue (16.3%), and respiratory (15.9%) isolates. MICs of cefiderocol ranged from ≤0.03 to 16 mg/liter, whereas the MIC90 was 0.125 mg/liter. Based upon CLSI clinical breakpoints for cefiderocol against Pseudomonas aeruginosa, Acinetobacter baumannii, and Stenotrophomonas maltophilia, three isolates (1.2%) would be classified as nonsusceptible (MIC > 4 mg/liter). Using EUCAST non-species-specific (pharmacokinetic/pharmacodynamic [PK/PD]) clinical breakpoints or those set for Pseudomonas aeruginosa, four isolates (1.6%) would be resistant (MIC > 2 mg/liter). Further testing for coresistance to meropenem, ceftazidime, trimethoprim-sulfamethoxazole, amoxicillin-clavulanate, and doxycycline was performed on the four isolates with elevated cefiderocol MICs (>2 mg/liter); all isolates exhibited resistance to amoxicillin-clavulanic acid, while three isolates also displayed resistance to at least one other antimicrobial. Cefiderocol was found to be highly active in vitro against B. pseudomallei primary clinical isolates. This compound shows great potential for the treatment of melioidosis in countries of endemicity and should be explored further.
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Affiliation(s)
- Delaney Burnard
- University of Queensland Centre for Clinical Research, Herston, Queensland, Australia
| | - Gemma Robertson
- University of Queensland Centre for Clinical Research, Herston, Queensland, Australia
- Pathology Queensland, Queensland Health, Herston, Queensland, Australia
- Forensic and Scientific Services, Queensland Health, Coopers Plains, Queensland, Australia
| | - Andrew Henderson
- University of Queensland Centre for Clinical Research, Herston, Queensland, Australia
- Princess Alexandra Hospital, Queensland Health, Woolloongabba, Queensland, Australia
| | - Caitlin Falconer
- University of Queensland Centre for Clinical Research, Herston, Queensland, Australia
| | - Michelle J Bauer
- University of Queensland Centre for Clinical Research, Herston, Queensland, Australia
| | - Kyra Cottrell
- University of Queensland Centre for Clinical Research, Herston, Queensland, Australia
| | - Ian Gassiep
- University of Queensland Centre for Clinical Research, Herston, Queensland, Australia
- Department of Infectious Diseases, Mater Hospital, Brisbane, Queensland, Australia
| | - Robert Norton
- Townsville Hospital and Health Service, Townsville, Queensland, Australia
- Faculty of Medicine, University of Queensland, Herston, Queensland, Australia
| | - David L Paterson
- University of Queensland Centre for Clinical Research, Herston, Queensland, Australia
- Royal Brisbane and Women's Hospital, Queensland Health, Herston, Queensland, Australia
| | - Patrick N A Harris
- University of Queensland Centre for Clinical Research, Herston, Queensland, Australia
- Pathology Queensland, Queensland Health, Herston, Queensland, Australia
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22
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Boyer PN, Woods ML. Burkholderia pseudomallei sepsis with osteoarticular melioidosis of the hip in a patient with diabetes mellitus. BMJ Case Rep 2020; 13:13/12/e238200. [PMID: 33370949 DOI: 10.1136/bcr-2020-238200] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/03/2022] Open
Abstract
Melioidosis is caused by the tropical soil pathogen Burkholderia pseudomallei Infection, usually in the form of pneumonia, disproportionately affects people with a risk factor for immune dysregulation and mortality remains high even with treatment. Climate change and increasing rates of diabetes render the populations of endemic areas increasingly vulnerable to the disease, which is emerging as a serious global health threat. We present here a case of a 68-year-old man from northern Australia with sepsis and osteoarticular melioidosis of the hip, and explore the links between diabetes mellitus and melioidosis, particularly with respect to musculoskeletal infection.
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Affiliation(s)
- Pierre-Nicolas Boyer
- Internal Medicine, Townsville University Hospital, Townsville, Queensland, Australia
| | - Marion L Woods
- Infectious Diseases, Townsville University Hospital, Townsville, Queensland, Australia.,Faculty of Medicine, University of Queensland, Brisbane, Queensland, Australia
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23
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Owen W, Smith S, Kuruvath S, Anderson D, Hanson J. Melioidosis of the central nervous system; A potentially lethal impersonator. IDCases 2020; 23:e01015. [PMID: 33304815 PMCID: PMC7708931 DOI: 10.1016/j.idcr.2020.e01015] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/21/2020] [Revised: 11/13/2020] [Accepted: 11/14/2020] [Indexed: 11/17/2022] Open
Abstract
A 57-year-old Australian woman, with a history of hazardous alcohol consumption, presented with a seizure following 2 days of fever and headache. Initial imaging suggested the presence of an isolated brain abscess, however, a thorough physical examination, identified no additional septic focus. Five sets of blood cultures were sterile and serology for Burkholderia pseudomallei was negative. Other investigations including computed tomography of her chest, abdomen and pelvis and a trans-esophageal echocardiogram were normal. Despite the administration of intravenous vancomycin, ceftriaxone, and metronidazole, her condition deteriorated. At emergency craniotomy, the abscess was drained and B. pseudomallei was cultured, confirming a diagnosis of melioidosis. She received 8 weeks of intravenous meropenem, combined with oral trimethoprim/sulfamethoxazole; the trimethoprim/sulfamethoxazole was continued for a total of 12 months. She recovered completely and was able to return to full-time work. Melioidosis, is endemic to Australia and South East Asia and, globally, is estimated to kill 89,000 every year. It can affect almost any organ, but up to 5% have central nervous system (CNS) involvement, where it may present as an encephalomyelitis, brain abscess or meningitis. B. pseudomallei is resistant to many commonly used antibiotics and even in well-resourced settings the case-fatality rate of CNS infection may rise to 50 %. This patient lived in a melioid-endemic region, and, with hazardous alcohol consumption, had a classical risk factor for the disease, but the sterile blood cultures and negative B. pseudomallei serology delayed definitive therapy. Despite the delayed diagnosis, definitive drainage and prolonged anti-bacterial therapy ensured a complete recovery.
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Affiliation(s)
- William Owen
- Department of Surgery, Cairns Hospital, Cairns, Queensland, Australia
| | - Simon Smith
- Department of Medicine, Cairns Hospital, Cairns, Queensland, Australia
| | - Sarin Kuruvath
- Department of Neurosurgery, Townsville University Hospital, Townsville, Queensland, Australia
| | - David Anderson
- Department of Neurosurgery, Townsville University Hospital, Townsville, Queensland, Australia
| | - Josh Hanson
- Department of Medicine, Cairns Hospital, Cairns, Queensland, Australia
- The Kirby Institute, University of New South Wales, Sydney, Australia
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24
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Hamdoon S, Wilson I, Smith S, Gericke C. Melioidosis of the nervous system: atypical presentation of a rare disease in a 48-year-old man. BMJ Case Rep 2020; 13:e233498. [PMID: 33148566 PMCID: PMC7640452 DOI: 10.1136/bcr-2019-233498] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 04/29/2020] [Indexed: 11/04/2022] Open
Abstract
A 48-year-old man who worked in mining in remote, northern Australia was transferred from a rural hospital 5 days after the onset of headaches, subjective fevers and flaccid paralysis of the left upper limb. Initial investigations demonstrated inflammatory cerebrospinal fluid (CSF) changes and a longitudinally extensive cervical cord lesion. Given two serial negative blood and CSF cultures, he was treated as inflammatory myelitis with intravenous methylprednisolone. Despite the initial improvement in pain and left arm power, the patient's neurological deficit plateaued and then deteriorated with worsening neck pain, diaphragmatic dysfunction and dysphagia requiring intubation and respiratory support. A third CSF culture isolated Burkholderia pseudomallei confirming a diagnosis of neuro-melioidosis. Repeat imaging revealed the rostral extension of the original spinal cord lesion into the medulla and pons. Over the next 4 weeks, the patient's neurological deficits slowly improved with continued intravenous antibiotic therapy with meropenem and oral trimethoprim/sulfamethoxazole.
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Affiliation(s)
- Saif Hamdoon
- Department of Medicine, Cairns and Hinterland Hospital and Health Service, Cairns, Queensland, Australia
| | - Ian Wilson
- Department of Neurology, Queensland Health, Cairns, Queensland, Australia
| | - Simon Smith
- Department of Infectious Diseases, Cairns and Hinterland Hospital and Health Service, Cairns, Queensland, Australia
| | - Christian Gericke
- Department of Neurology, The Prince Charles Hospital, Chermside, Queensland, Australia
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25
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Polymicrobial community-acquired Acinetobacter baumannii and Burkholderia pseudomallei bacteremia: opportunistic infections with similar risk factors in northern Australia. IDCases 2020; 21:e00833. [PMID: 32509526 PMCID: PMC7264049 DOI: 10.1016/j.idcr.2020.e00833] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/19/2020] [Revised: 05/19/2020] [Accepted: 05/19/2020] [Indexed: 11/25/2022] Open
Abstract
We report the case of a 61-year-old man from northern Australia with concurrent community-onset Acinetobacter baumannii complex and Burkholderia pseudomallei bacteremia presenting as severe tropical pneumonia requiring intensive care unit support. The pneumonia was complicated by L3/4 discitis and vertebral osteomyelitis presumed to be due to melioidosis. His risk factors included chronic lung disease and immunosuppression with etanercept. This case of concurrent infection highlights the similar risk factors, presentation and epidemiology of both infections, emphasises the importance of accurate microbiologic identification and reinforces the current Australian empiric antimicrobial treatment recommendations for severe tropical pneumonia.
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26
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Whole-genome sequencing of Burkholderia pseudomallei from an urban melioidosis hot spot reveals a fine-scale population structure and localised spatial clustering in the environment. Sci Rep 2020; 10:5443. [PMID: 32214186 PMCID: PMC7096523 DOI: 10.1038/s41598-020-62300-8] [Citation(s) in RCA: 16] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/23/2019] [Accepted: 12/17/2019] [Indexed: 11/12/2022] Open
Abstract
Melioidosis is a severe disease caused by the environmental bacterium Burkholderia pseudomallei that affects both humans and animals throughout northern Australia, Southeast Asia and increasingly globally. While there is a considerable degree of genetic diversity amongst isolates, B. pseudomallei has a robust global biogeographic structure and genetic populations are spatially clustered in the environment. We examined the distribution and local spread of B. pseudomallei in Darwin, Northern Territory, Australia, which has the highest recorded urban incidence of melioidosis globally. We sampled soil and land runoff throughout the city centre and performed whole-genome sequencing (WGS) on B. pseudomallei isolates. By combining phylogenetic analyses, Bayesian clustering and spatial hot spot analysis our results demonstrate that some sequence types (STs) are widespread in the urban Darwin environment, while others are highly spatially clustered over a small geographic scale. This clustering matches the spatial distribution of clinical cases for one ST. Results also demonstrate a greater overall isolate diversity recovered from drains compared to park soils, further supporting the role drains may play in dispersal of B. pseudomallei STs in the environment. Collectively, knowledge gained from this study will allow for better understanding of B. pseudomallei phylogeography and melioidosis source attribution, particularly on a local level.
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27
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Abstract
The causative agent of melioidosis, Burkholderia pseudomallei, a tier 1 select agent, is endemic in Southeast Asia and northern Australia, with increased incidence associated with high levels of rainfall. Increasing reports of this condition have occurred worldwide, with estimates of up to 165,000 cases and 89,000 deaths per year. The ecological niche of the organism has yet to be clearly defined, although the organism is associated with soil and water. The culture of appropriate clinical material remains the mainstay of laboratory diagnosis. Identification is best done by phenotypic methods, although mass spectrometric methods have been described. Serology has a limited diagnostic role. Direct molecular and antigen detection methods have limited availability and sensitivity. Clinical presentations of melioidosis range from acute bacteremic pneumonia to disseminated visceral abscesses and localized infections. Transmission is by direct inoculation, inhalation, or ingestion. Risk factors for melioidosis include male sex, diabetes mellitus, alcohol abuse, and immunosuppression. The organism is well adapted to intracellular survival, with numerous virulence mechanisms. Immunity likely requires innate and adaptive responses. The principles of management of this condition are drainage and debridement of infected material and appropriate antimicrobial therapy. Global mortality rates vary between 9% and 70%. Research into vaccine development is ongoing.
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Affiliation(s)
- I Gassiep
- Pathology Queensland, Townsville Hospital, Townsville, Queensland, Australia
- Faculty of Medicine, University of Queensland, Brisbane, Queensland, Australia
| | - M Armstrong
- Pathology Queensland, Townsville Hospital, Townsville, Queensland, Australia
| | - R Norton
- Pathology Queensland, Townsville Hospital, Townsville, Queensland, Australia
- Faculty of Medicine, University of Queensland, Brisbane, Queensland, Australia
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28
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Hanson J, Smith S. High Rates of Premature and Potentially Preventable Death among Patients Surviving Melioidosis in Tropical Australia. Am J Trop Med Hyg 2020; 101:328-331. [PMID: 31264566 DOI: 10.4269/ajtmh.19-0375] [Citation(s) in RCA: 11] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/14/2023] Open
Abstract
Although the in-hospital mortality of Australian patients with melioidosis continues to decline, the ensuing clinical course of survivors is poorly described. Between January 1, 1998, and January 31, 2019, 228 patients in Cairns, tropical Australia, survived their hospitalization with melioidosis; however, 52 (23%) subsequently died. Death occurred at a median of 3.8 years after discharge, with patients dying at a mean age of 59 years. Only 1/27 (4%) without predisposing conditions for melioidosis died during follow-up, versus 51/201 (25%) with these comorbidities (P = 0.01). Death during follow-up was more likely in patients with chronic lung disease (OR [95% CI]: 4.05 (1.84-8.93, P = 0.001) and chronic kidney disease (OR [95% CI]: 2.87 [1.33-6.20], P = 0.007), and was most commonly due to infection and macrovascular disease. A significant proportion of Australians surviving hospitalization with melioidosis will die soon after discharge, usually prematurely and frequently from preventable conditions. A more holistic approach is required to their care.
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Affiliation(s)
- Josh Hanson
- The Kirby Institute, University of New South Wales, Sydney, Australia.,Department of Medicine, Cairns Hospital, Cairns, Australia
| | - Simon Smith
- Department of Medicine, Cairns Hospital, Cairns, Australia
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29
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Hempenstall AJ, Smith S, Stanton D, Hanson J. Melioidosis in the Torres Strait Islands, Australia: Exquisite Interplay between Pathogen, Host, and Environment. Am J Trop Med Hyg 2020; 100:517-521. [PMID: 30675834 DOI: 10.4269/ajtmh.18-0806] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/07/2022] Open
Abstract
Burkholderia pseudomallei, a bacterium that lives in the soil of the tropics, causes the disease melioidosis. This retrospective study investigated the temporospatial epidemiology of the 49 laboratory-confirmed melioidosis cases in the Torres Straits Islands of tropical Australia between 1997 and 2017. An identifiable risk factor for the disease was present in 43/49 (88%) cases and in 35/36 (97%) cases with complete clinical data. The mean incidence of melioidosis varied across the region, from 0/100,000 persons/year in the Eastern Island Cluster to 116.1/100,000 persons/year in the Near Western Island Cluster. An environmental suitability score for the growth of B. pseudomallei-constructed using the rainfall, vegetation, and soil type on each island-correlated with disease incidence (Spearman's rho 0.51; P = 0.035). Melioidosis is an opportunistic disease that occurs in patients with specific risk factors, but its incidence is also strongly influenced by environmental factors that favor the growth of the causative organism.
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Affiliation(s)
| | - Simon Smith
- James Cook University, Cairns, Australia.,Department of Medicine, Cairns Hospital, Cairns, Australia
| | | | - Josh Hanson
- Department of Medicine, Cairns Hospital, Cairns, Australia.,The Kirby Institute, Sydney, Australia
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30
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Hantrakun V, Kongyu S, Klaytong P, Rongsumlee S, Day NPJ, Peacock SJ, Hinjoy S, Limmathurotsakul D. Clinical Epidemiology of 7126 Melioidosis Patients in Thailand and the Implications for a National Notifiable Diseases Surveillance System. Open Forum Infect Dis 2019; 6:ofz498. [PMID: 32083145 PMCID: PMC7020769 DOI: 10.1093/ofid/ofz498] [Citation(s) in RCA: 35] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/10/2019] [Accepted: 11/17/2019] [Indexed: 12/14/2022] Open
Abstract
Background National notifiable diseases surveillance system (NNDSS) data in developing countries are usually incomplete, yet the total number of fatal cases reported is commonly used in national priority-setting. Melioidosis, an infectious disease caused by Burkholderia pseudomallei, is largely underrecognized by policy-makers due to the underreporting of fatal cases via the NNDSS. Methods Collaborating with the Epidemiology Division (ED), Ministry of Public Health (MoPH), we conducted a retrospective study to determine the incidence and mortality of melioidosis cases already identified by clinical microbiology laboratories nationwide. A case of melioidosis was defined as a patient with any clinical specimen culture positive for B. pseudomallei. Routinely available microbiology and hospital databases of secondary care and tertiary care hospitals, the national death registry, and NNDSS data were obtained for analysis. Results A total of 7126 culture-confirmed melioidosis patients were identified from 2012 to 2015 in 60 hospitals countrywide. The total number of cases diagnosed in Northeast, Central, South, East, North, and West Thailand were 5475, 536, 374, 364, 358, and 19 cases, respectively. The overall 30-day mortality was 39% (2805/7126). Only 126 (4%) deaths were reported to the NNDSS. Age, presentation with bacteremia and pneumonia, prevalence of diabetes, and 30-day mortality differed by geographical region (all P < .001). The ED at MoPH has agreed to include the findings of our study in the next annual report of the NNDSS. Conclusions Melioidosis is an important cause of death in Thailand nationwide, and its clinical epidemiology may be different by region. In developing countries, NNDSS data can be supplemented by integrating information from readily available routine data sets.
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Affiliation(s)
- Viriya Hantrakun
- Mahidol-Oxford Tropical Medicine Research Unit (MORU), Faculty of Tropical Medicine, Mahidol University, Bangkok, Thailand
| | - Somkid Kongyu
- Epidemiology Division, Department of Disease Control, Ministry of Public Health, Nonthaburi, Thailand
| | - Preeyarach Klaytong
- Mahidol-Oxford Tropical Medicine Research Unit (MORU), Faculty of Tropical Medicine, Mahidol University, Bangkok, Thailand
| | - Sittikorn Rongsumlee
- Mahidol-Oxford Tropical Medicine Research Unit (MORU), Faculty of Tropical Medicine, Mahidol University, Bangkok, Thailand
| | - Nicholas P J Day
- Mahidol-Oxford Tropical Medicine Research Unit (MORU), Faculty of Tropical Medicine, Mahidol University, Bangkok, Thailand.,Centre for Tropical Medicine and Global Health, Nuffield Department of Clinical Medicine, Old Road Campus, University of Oxford, Oxford, United Kingdom
| | - Sharon J Peacock
- Department of Medicine, University of Cambridge, Cambridge, United Kingdom
| | - Soawapak Hinjoy
- Epidemiology Division, Department of Disease Control, Ministry of Public Health, Nonthaburi, Thailand.,Office of International Cooperation, Department of Disease Control, Ministry of Public Health, Nonthaburi, Thailand
| | - Direk Limmathurotsakul
- Mahidol-Oxford Tropical Medicine Research Unit (MORU), Faculty of Tropical Medicine, Mahidol University, Bangkok, Thailand.,Centre for Tropical Medicine and Global Health, Nuffield Department of Clinical Medicine, Old Road Campus, University of Oxford, Oxford, United Kingdom.,Department of Tropical Hygiene, Faculty of Tropical Medicine, Mahidol University, Bangkok, Thailand
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