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Stockton JL, Khakhum N, Stevenson HL, Torres AG. Burkholderia pseudomallei BicA protein promotes pathogenicity in macrophages by regulating invasion, intracellular survival, and virulence. mSphere 2023; 8:e0037823. [PMID: 37768049 PMCID: PMC10597401 DOI: 10.1128/msphere.00378-23] [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: 07/10/2023] [Accepted: 08/08/2023] [Indexed: 09/29/2023] Open
Abstract
Burkholderia pseudomallei (Bpm) is the causative agent of melioidosis disease. Bpm is a facultative intracellular pathogen with a complex life cycle inside host cells. Pathogenic success depends on a variety of virulence factors with one of the most critical being the type 6 secretion system (T6SS). Bpm uses the T6SS to move into neighboring cells, resulting in multinucleated giant cell (MNGC) formation, a strategy used to disseminate from cell to cell. Our prior study using a dual RNA-seq analysis to dissect T6SS-mediated virulence on intestinal epithelial cells identified BicA as a factor upregulated in a T6SS mutant. BicA regulates both type 3 secretion system (T3SS) and T6SSs; however, the extent of its involvement during disease progression is unclear. To fully dissect the role of BicA during systemic infection, we used two macrophage cell lines paired with a pulmonary in vivo challenge murine model. We found that ΔbicA has a distinct intracellular replication defect in both immortalized and primary macrophages, which begins as early as 1 h post-infection. This intracellular defect is linked with the lack of cell-to-cell dissemination and MNGC formation as well as a defect in T3SS expression. The in vitro phenotype translated in vivo as ΔbicA was attenuated in a pulmonary model of infection, demonstrating a distinct macrophage activation profile and a lack of pathological features present in the wild type. Overall, these results highlight the role of BicA in regulating intracellular virulence and demonstrate that specific regulation of secretion systems has a significant effect on host response and Bpm pathogenesis. IMPORTANCE Melioidosis is an understudied tropical disease that still results in ~50% fatalities in infected patients. It is caused by the Gram-negative bacillus Burkholderia pseudomallei (Bpm). Bpm is an intracellular pathogen that disseminates from the infected cell to target organs, causing disseminated disease. The regulation of secretion systems involved in entry and cell-to-cell spread is poorly understood. In this work, we characterize the role of BicA as a regulator of secretion systems during infection of macrophages in vitro and in vivo. Understanding how these virulence factors are controlled will help us determine their influence on the host cells and define the macrophage responses associated with bacterial clearance.
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Affiliation(s)
- Jacob L. Stockton
- Department of Microbiology & Immunology, University of Texas Medical Branch, Galveston, Texas, USA
| | - Nittaya Khakhum
- Department of Microbiology & Immunology, University of Texas Medical Branch, Galveston, Texas, USA
| | - Heather L. Stevenson
- Department of Pathology, University of Texas Medical Branch, Galveston, Texas, USA
| | - Alfredo G. Torres
- Department of Microbiology & Immunology, University of Texas Medical Branch, Galveston, Texas, USA
- Department of Pathology, University of Texas Medical Branch, Galveston, Texas, USA
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Savelkoel J, Tiemensma M, Birnie E, Wiersinga WJ, Currie BJ, Roelofs JJTH. A Graphical Overview of the Histopathology of Human Melioidosis: A Case Series. Open Forum Infect Dis 2023; 10:ofad367. [PMID: 37547853 PMCID: PMC10400137 DOI: 10.1093/ofid/ofad367] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/15/2023] [Accepted: 07/11/2023] [Indexed: 08/08/2023] Open
Abstract
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.
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Affiliation(s)
- Jelmer Savelkoel
- Center for Experimental and Molecular Medicine, Amsterdam UMC location University of Amsterdam, Amsterdam, the Netherlands
| | - Marianne Tiemensma
- Territory Pathology, Royal Darwin Hospital, Darwin, Northern Territory, Australia
| | - Emma Birnie
- Center for Experimental and Molecular Medicine, Amsterdam UMC location University of Amsterdam, Amsterdam, the Netherlands
| | - W Joost Wiersinga
- Center for Experimental and Molecular Medicine, Amsterdam UMC location University of Amsterdam, Amsterdam, the Netherlands
- Division of Infectious Diseases, Amsterdam UMC location University of Amsterdam, Amsterdam, the Netherlands
| | - Bart J Currie
- Global and Tropical Health Division, Menzies School of Health Research, Charles Darwin University, Darwin, Northern Territory, Australia
- Infectious Diseases Department, Royal Darwin Hospital, Darwin, Northern Territory, Australia
| | - Joris J T H Roelofs
- Department of Pathology, Amsterdam UMC location University of Amsterdam, Amsterdam, the Netherlands
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Abstract
The soil saprophyte, Burkholderia pseudomallei, is the causative agent of melioidosis, a disease endemic in South East Asia and northern Australia. Exposure to B. pseudomallei by either inhalation or inoculation can lead to severe disease. B. pseudomallei rapidly shifts from an environmental organism to an aggressive intracellular pathogen capable of rapidly spreading around the body. The expression of multiple virulence factors at every stage of intracellular infection allows for rapid progression of infection. Following invasion or phagocytosis, B. pseudomallei resists host-cell killing mechanisms in the phagosome, followed by escape using the type III secretion system. Several secreted virulence factors manipulate the host cell, while bacterial cells undergo a shift in energy metabolism allowing for overwhelming intracellular replication. Polymerisation of host cell actin into “actin tails” propels B. pseudomallei to the membranes of host cells where the type VI secretion system fuses host cells into multinucleated giant cells (MNGCs) to facilitate cell-to-cell dissemination. This review describes the various mechanisms used by B. pseudomallei to survive within cells.
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Affiliation(s)
- Nicole M Bzdyl
- The Marshall Centre for Infectious Diseases Research and Training, School of Biomedical Sciences, University of Western Australia, Perth, Western Australia, 6009, Australia
| | - Clare L Moran
- The Marshall Centre for Infectious Diseases Research and Training, School of Biomedical Sciences, University of Western Australia, Perth, Western Australia, 6009, Australia
| | - Justine Bendo
- The Marshall Centre for Infectious Diseases Research and Training, School of Biomedical Sciences, University of Western Australia, Perth, Western Australia, 6009, Australia
| | - Mitali Sarkar-Tyson
- The Marshall Centre for Infectious Diseases Research and Training, School of Biomedical Sciences, University of Western Australia, Perth, Western Australia, 6009, Australia
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Wu H, Wang X, Zhou X, Chen S, Mai W, Huang H, You Z, Zhang S, Zhang X, Lu B. Osteomyelitis and Septic Arthritis Due to Burkholderia pseudomallei: A 10-Year Retrospective Melioidosis Study From South China. Front Cell Infect Microbiol 2021; 11:654745. [PMID: 34123870 PMCID: PMC8194086 DOI: 10.3389/fcimb.2021.654745] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/25/2021] [Accepted: 05/04/2021] [Indexed: 01/07/2023] Open
Abstract
Burkholderia pseudomallei is the causative agent of melioidosis, endemic mainly in tropical and subtropical areas. Its clinical manifestation is broad ranging from a localized skin lesion to a life-threatening systemic disease. Osteomyelitis and septic arthritis caused by B. pseudomallei are a rare, fatal illness, whose clinical features have not been illustrated in mainland China. Over 10 years (2010 to 2019), of 334 culture-confirmed melioidosis in Hainan province, China, 44 patients (13.2%) were confirmed to have osteomyelitis and septic arthritis through the combination of clinical features, imaging examination and microbiological culture. Herein, we summarized these 44 patients' clinical manifestations, demographical features, antibiotic treatment, and outcomes. Of them, osteomyelitis and septic arthritis accounted for 25 (56.8%) and 15 (34.1%), respectively, and 4 patients (9.1%) had both. The gender ratio of male/female was approximately 13.7:1; diabetes mellitus was the most common risk factor (38/44, 86.4%); imipenem and trimethoprim/sulfamethoxazole were the most frequently used antibiotics. Most B. pseudomallei strains were isolated from blood samples (41/44, 93.2%). After surgical handling, antibiotic treatment, or both, 9 patients died, with a mortality rate of 20.5%. In summary, in melioidosis endemic areas, for patients with both localized manifestations of joint and bone and a positive B. pseudomallei blood culture, increased awareness is required for melioidotic osteomyelitis and septic arthritis.
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Affiliation(s)
- Hua Wu
- Department of Laboratory Medicine, Affiliated Hainan Hospital of Hainan Medical College, Haikou, China
| | - Xuming Wang
- Department of Laboratory Medicine, Affiliated Hainan Hospital of Hainan Medical College, Haikou, China
| | - Xiaojun Zhou
- Department of Laboratory Medicine, Affiliated Hainan Hospital of Hainan Medical College, Haikou, China
| | - Shaowen Chen
- Department of Laboratory Medicine, Second Affiliated Hospital of Hainan Medical College, Haikou, China
| | - Wenhui Mai
- Department of Laboratory Medicine, Haikou Third People’s Hospital, Haikou, China
| | - Hui Huang
- Department of Laboratory Medicine, Affiliated Haikou Hospital of Xiangya Medical College, Central South University, Haikou, China
| | - Zelin You
- Department of Laboratory Medicine, Ling Shui Li Autonomous County People’s Hospital, Lingshui, China
| | - Suling Zhang
- Department of Laboratory Medicine, Danzhou People’s Hospital, Danzhou, China
| | - Xiuxia Zhang
- Department of Laboratory Medicine, The Second People’s Hospital of Ledong County, Ledong, China
| | - Binghuai Lu
- Laboratory of Clinical Microbiology and Infectious Diseases, Department of Pulmonary and Critical Care Medicine, China-Japan Friendship Hospital, National Clinical Research Center of Respiratory Diseases, Beijing, China
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Abstract
Melioidosis is a potentially fatal bacterial infection caused by the Gram-negative bacillus, Burkholderia pseudomallei following contact with a contaminated environmental source, normally soil or water in tropical and subtropical locations. The disease spectrum varies from rapidly progressive bacteraemic infection with or without pneumonia, to focal lesions in deep soft tissues and internal organs to superficial soft tissue infection and asymptomatic seroconversion with possible long-term dormancy. Most infections occur with a background of chronic illness such as diabetes, chronic kidney disease and alcoholic liver disease. Improvements in diagnosis, targeted antimicrobial treatment and long term follow up have improved clinical outcomes. Environmental controls following rare point source case clusters and heightened awareness of melioidosis appear to have reduced the disease burden in some parts of northern Australia. However, the impact of climate change on dispersal of environmental B. pseudomallei, and changing land use in tropical Australia is expected to change the epidemiology of melioidosis in future.
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Baikunje N, Gangaramajalu S, Hosmane GB. Melioidosis: A Fulminant Infection in a Patient with Uncontrolled Diabetes. JOURNAL OF HEALTH AND ALLIED SCIENCES NU 2020. [DOI: 10.1055/s-0040-1721232] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/22/2022]
Abstract
AbstractMelioidosis is an endemic infection in Southeast Asia and Northern Australia commonly manifesting with pneumonia and localized skin infection. Though most exposures do not lead to severe illness, a fulminant infection can occur among patients with risk factors. A 59-year-old male presented with cough with expectoration and fever for 1 week. He had diabetes for 10 years with poorly controlled blood sugars. Contrast-enhanced computerized tomography (CECT) of thorax showed right upper lobe consolidation with diffuse ground-glass opacities in right upper lobe along with microabscesses in liver and spleen. Sputum culture and Xpert mycobacterium tuberculosis complex and resistance to rifampin (MTB/RIF) for tuberculosis were negative. Bronchoalveolar lavage culture grew Burkholderia pseudomallei. He was treated with initial intensive therapy with injection amoxicillin-clavulanic acid for 2 weeks and subsequently started on eradication therapy with tablet trimethoprim-sulfamethoxazole. Diagnosis of melioidosis should be considered in a patient of pneumonia with multiorgan involvement in an endemic area, especially with underlying risk factors.
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Affiliation(s)
- Nandakishore Baikunje
- Department of Pulmonary Medicine, K.S. Hegde Medical Academy, NITTE (Deemed to be University), Mangaluru, Karnataka, India
| | - Suresh Gangaramajalu
- Department of General Medicine, K.S. Hegde Medical Academy, NITTE (Deemed to be University), Mangaluru, Karnataka, India
| | - Giridhar Belur Hosmane
- Department of Pulmonary Medicine, K.S. Hegde Medical Academy, NITTE (Deemed to be University), Mangaluru, Karnataka, India
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Multinucleated Giant Cell Formation as a Portal to Chronic Bacterial Infections. Microorganisms 2020; 8:microorganisms8111637. [PMID: 33113944 PMCID: PMC7690659 DOI: 10.3390/microorganisms8111637] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/18/2020] [Revised: 10/16/2020] [Accepted: 10/21/2020] [Indexed: 12/20/2022] Open
Abstract
This review provides a snapshot of chronic bacterial infections through the lens of Burkholderia pseudomallei and detailing its ability to establish multi-nucleated giant cells (MNGC) within the host, potentially leading to the formation of pyogranulomatous lesions. We explore the role of MNGC in melioidosis disease progression and pathology by comparing the similarities and differences of melioidosis to tuberculosis, outline the concerted events in pathogenesis that lead to MNGC formation, discuss the factors that influence MNGC formation, and consider how they fit into clinical findings reported in chronic cases. Finally, we speculate about future models and techniques that can be used to delineate the mechanisms of MNGC formation and function.
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