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Uthaya Kumar A, Ahmad Zan M, Ng CL, Chieng S, Nathan S. Diabetes and Infectious Diseases with a Focus on Melioidosis. Curr Microbiol 2024; 81:208. [PMID: 38833191 DOI: 10.1007/s00284-024-03748-z] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/12/2024] [Accepted: 05/19/2024] [Indexed: 06/06/2024]
Abstract
Diabetes mellitus (DM) leads to impaired innate and adaptive immune responses. This renders individuals with DM highly susceptible to microbial infections such as COVID-19, tuberculosis and melioidosis. Melioidosis is a tropical disease caused by the bacterial pathogen Burkholderia pseudomallei, where diabetes is consistently reported as the most significant risk factor associated with the disease. Type-2 diabetes is observed in 39% of melioidosis patients where the risk of infection is 13-fold higher than non-diabetic individuals. B. pseudomallei is found in the environment and is an opportunistic pathogen in humans, often exhibiting severe clinical manifestations in immunocompromised patients. The pathophysiology of diabetes significantly affects the host immune responses that play a critical role in fighting the infection, such as leukocyte and neutrophil impairment, macrophage and monocyte inhibition and natural killer cell dysfunction. These defects result in delayed recruitment as well as activation of immune cells to target the invading B. pseudomallei. This provides an advantage for the pathogen to survive and adapt within the immunocompromised diabetic patients. Nevertheless, knowledge gaps on diabetes-infectious disease comorbidity, in particular, melioidosis-diabetes comorbidity, need to be filled to fully understand the dysfunctional host immune responses and adaptation of the pathogen under diabetic conditions to guide therapeutic options.
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Affiliation(s)
- Asqwin Uthaya Kumar
- Department of Biological Sciences and Biotechnology, Faculty of Science and Technology, Universiti Kebangsaan Malaysia, Bangi, Malaysia
| | - Muhammad Ahmad Zan
- Department of Biological Sciences and Biotechnology, Faculty of Science and Technology, Universiti Kebangsaan Malaysia, Bangi, Malaysia
| | - Chyan-Leong Ng
- Institute of Systems Biology, Universiti Kebangsaan Malaysia, Bangi, Malaysia
| | - Sylvia Chieng
- Department of Biological Sciences and Biotechnology, Faculty of Science and Technology, Universiti Kebangsaan Malaysia, Bangi, Malaysia
| | - Sheila Nathan
- Department of Biological Sciences and Biotechnology, Faculty of Science and Technology, Universiti Kebangsaan Malaysia, Bangi, Malaysia.
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Li X, Wang S, Wu P, Nan D, Chen D, Suo L, Lu X, Rao C, Li Q, Yue J, Xiang Y, Mao X, Yan J. Effect of O antigen glycosyl isomerase gene mutation on biological property and pathogenicity of Burkholderia pseudomallei strain BPC006. Int J Biol Macromol 2024; 258:128922. [PMID: 38141699 DOI: 10.1016/j.ijbiomac.2023.128922] [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: 09/21/2023] [Revised: 12/13/2023] [Accepted: 12/18/2023] [Indexed: 12/25/2023]
Abstract
Burkholderia pseudomallei, an intracellular pathogen, is responsible for melioidosis, a zoonotic disease. Its pathogenesis involves several virulence factors, among which lipopolysaccharide (LPS) plays a crucial role. Our research reveals that the O antigen present within the LPS significantly regulates the host immune response. In a previous study, we obtained a B. pseudomallei mutant strain ΔwbiI. Here, the purification of LPS from ΔwbiI and a gas chromatography-mass spectrometry (GC-MS) analysis were conducted. The results confirmed the absence of specific sugar 6-deoxy-Talp, which is a typical component of the O antigen in the wild type B. pseudomallei. Our findings underscore the potent impact the O antigen exerts on the virulence of B. pseudomallei. The ΔwbiI strain displayed significantly increased invasiveness and cytotoxicity in vitro. This enhanced cytotoxicity seems to be related to the exposure of lipid A and an increased cell membrane hydrophobicity resulting from the deletion of the O antigen. Additionally, in mouse models, the ΔwbiI strain resulted in a heightened host lethality and an excessive inflammatory response in mice. These findings indicate that the O-antigenic polysaccharide moiety of B. pseudomallei plays a role in its pathogenicity in vitro and in vivo.
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Affiliation(s)
- Xiao Li
- Department of Clinical Microbiology and Immunology, College of Pharmacy and Medical Laboratory, Army Medical University (Third Military Medical University), Chongqing 400038, China
| | - Shiwei Wang
- Department of Clinical Microbiology and Immunology, College of Pharmacy and Medical Laboratory, Army Medical University (Third Military Medical University), Chongqing 400038, China
| | - Pan Wu
- Department of Clinical Microbiology and Immunology, College of Pharmacy and Medical Laboratory, Army Medical University (Third Military Medical University), Chongqing 400038, China
| | - Dongqi Nan
- Department of Clinical Microbiology and Immunology, College of Pharmacy and Medical Laboratory, Army Medical University (Third Military Medical University), Chongqing 400038, China
| | - Dan Chen
- Department of Clinical Microbiology and Immunology, College of Pharmacy and Medical Laboratory, Army Medical University (Third Military Medical University), Chongqing 400038, China
| | - Liangpeng Suo
- Department of Clinical Microbiology and Immunology, College of Pharmacy and Medical Laboratory, Army Medical University (Third Military Medical University), Chongqing 400038, China
| | - Xiaoxue Lu
- Department of Clinical Microbiology and Immunology, College of Pharmacy and Medical Laboratory, Army Medical University (Third Military Medical University), Chongqing 400038, China
| | - Chenglong Rao
- Department of Clinical Microbiology and Immunology, College of Pharmacy and Medical Laboratory, Army Medical University (Third Military Medical University), Chongqing 400038, China
| | - Qian Li
- Department of Clinical Microbiology and Immunology, College of Pharmacy and Medical Laboratory, Army Medical University (Third Military Medical University), Chongqing 400038, China
| | - Juanjuan Yue
- Department of Clinical Microbiology and Immunology, College of Pharmacy and Medical Laboratory, Army Medical University (Third Military Medical University), Chongqing 400038, China
| | - Yang Xiang
- Department of Clinical Microbiology and Immunology, College of Pharmacy and Medical Laboratory, Army Medical University (Third Military Medical University), Chongqing 400038, China
| | - Xuhu Mao
- Department of Clinical Microbiology and Immunology, College of Pharmacy and Medical Laboratory, Army Medical University (Third Military Medical University), Chongqing 400038, China.
| | - Jingmin Yan
- Department of Clinical Microbiology and Immunology, College of Pharmacy and Medical Laboratory, Army Medical University (Third Military Medical University), Chongqing 400038, China.
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Phillips ED, Garcia EC. Burkholderia pseudomallei. Trends Microbiol 2024; 32:105-106. [PMID: 37634974 PMCID: PMC10803057 DOI: 10.1016/j.tim.2023.07.008] [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: 05/08/2023] [Revised: 07/13/2023] [Accepted: 07/14/2023] [Indexed: 08/29/2023]
Abstract
Burkholderia pseudomallei is a Gram negative, facultative intracellular bacterium that resides in the rhizosphere of tropical soils. B. pseudomallei causes melioidosis, which is transmitted by cutaneous entry, ingestion, or inhalation of contaminated soil or water. Infection with B. pseudomallei can cause a wide array of clinical symptoms such as pneumonia, bone, joint, skin, genitourinary, and central nervous system infections, as well as parotid abscesses in children. Mammalian virulence is linked to the B. pseudomallei intracellular life cycle, which begins with attachment and internalization by host cells. B. pseudomallei can infect a wide range of eukaryotic cells, including macrophages, monocytes, and neutrophils, as well as nonphagocytic cells. Once internalized, a type 3 secretion system (T3SSBsa) facilitates B. pseudomallei escape from the phagosome, and the bacteria replicate in the cytoplasm. Autotransporter protein BimA mediates actin polymerization, enabling B. pseudomallei to spread, cell to cell, using actin-based motility. This process, coupled with the activity of a type 6 secretion system (T6SS-5), results in host membrane fusion and the formation of multinucleated giant cells. Capsule polysaccharides also contribute to virulence and evasion of host innate immunity. Treatment of B. pseudomallei infections is complicated by the organism’s intrinsic resistance to multiple classes of antimicrobials, largely due to an abundance of efflux pumps and reduced outer membrane permeability. While B. pseudomallei is commonly associated with endemic ‘hotspots’ in southeast Asia and northern Australia, there is increasing evidence that it is likely endemic in a large range of tropical and subtropical areas, including regions in Africa, South America, the Middle East, Central America, and the Caribbean. Soil and climate conditions favorable for B. pseudomallei survival are also found in additional areas worldwide. Consequently, it is important for clinical and public health laboratories located outside of high-endemicity areas to be aware of B. pseudomallei , as well as for improved diagnostic and reporting methods.
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Affiliation(s)
- Erica D Phillips
- University of Kentucky College of Medicine, Lexington, KY 40536, USA
| | - Erin C Garcia
- University of Kentucky College of Medicine, Lexington, KY 40536, USA.
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Wu P, Rao C, Liu W, Zhang Z, Nan D, Chen J, Wang M, Wen Y, Yan J, Yue J, Mao X, Li Q. Anti-Hcp1 Monoclonal Antibody Is Protective against Burkholderia pseudomallei Infection via Recognizing Amino Acids at Asp95-Leu114. Pathogens 2023; 13:43. [PMID: 38251350 PMCID: PMC10818278 DOI: 10.3390/pathogens13010043] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/13/2023] [Revised: 12/21/2023] [Accepted: 12/27/2023] [Indexed: 01/23/2024] Open
Abstract
Melioidosis, a severe tropical illness caused by Burkholderia pseudomallei, poses significant treatment challenges due to limited therapeutic options and the absence of effective vaccines. The pathogen's intrinsic resistance to numerous antibiotics and propensity to induce sepsis during acute infections further complicate management strategies. Thus, exploring alternative methods for prevention and treatment is crucial. Monoclonal antibodies (mAbs) have emerged as a promising strategy for the prevention and treatment of infectious diseases. This study focused on generating three mAbs (13F1, 14G11, and 15D9) targeting hemolysin-coregulated protein 1 (Hcp1), a protein involved in the type VI secretion system cluster 1 (T6SS1) of B. pseudomallei. Notably, pretreatment with 13F1 mAb significantly reduced the intracellular survival of B. pseudomallei and inhibited the formation of macrophage-derived multinucleated giant cells (MNGCs). This protective effect was also observed in vivo. We identified a sequence of amino acids (Asp95-Leu114) within Hcp1 as the likely binding site for 13F1 mAb. In summary, our findings reveal that 13F1 mAb counteracts infection by targeting Hcp1, offering potential new targets and insights for melioidosis prevention.
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Affiliation(s)
- Pan Wu
- Department of Clinical Microbiology and Immunology, College of Pharmacy and Laboratory Medicine, Army Medical University (Third Military Medical University), Chongqing 400000, China; (P.W.); (W.L.); (J.C.); (M.W.); (Y.W.); (J.Y.)
| | - Chenglong Rao
- Department of Clinical Microbiology and Immunology, College of Pharmacy and Laboratory Medicine, Army Medical University (Third Military Medical University), Chongqing 400000, China; (P.W.); (W.L.); (J.C.); (M.W.); (Y.W.); (J.Y.)
| | - Wenzheng Liu
- Department of Clinical Microbiology and Immunology, College of Pharmacy and Laboratory Medicine, Army Medical University (Third Military Medical University), Chongqing 400000, China; (P.W.); (W.L.); (J.C.); (M.W.); (Y.W.); (J.Y.)
| | - Ziyuan Zhang
- Department of Clinical Microbiology and Immunology, College of Pharmacy and Laboratory Medicine, Army Medical University (Third Military Medical University), Chongqing 400000, China; (P.W.); (W.L.); (J.C.); (M.W.); (Y.W.); (J.Y.)
| | - Dongqi Nan
- Department of Clinical Microbiology and Immunology, College of Pharmacy and Laboratory Medicine, Army Medical University (Third Military Medical University), Chongqing 400000, China; (P.W.); (W.L.); (J.C.); (M.W.); (Y.W.); (J.Y.)
| | - Jiangao Chen
- Department of Clinical Microbiology and Immunology, College of Pharmacy and Laboratory Medicine, Army Medical University (Third Military Medical University), Chongqing 400000, China; (P.W.); (W.L.); (J.C.); (M.W.); (Y.W.); (J.Y.)
| | - Minyang Wang
- Department of Clinical Microbiology and Immunology, College of Pharmacy and Laboratory Medicine, Army Medical University (Third Military Medical University), Chongqing 400000, China; (P.W.); (W.L.); (J.C.); (M.W.); (Y.W.); (J.Y.)
| | - Yuan Wen
- Department of Clinical Microbiology and Immunology, College of Pharmacy and Laboratory Medicine, Army Medical University (Third Military Medical University), Chongqing 400000, China; (P.W.); (W.L.); (J.C.); (M.W.); (Y.W.); (J.Y.)
| | - Jingmin Yan
- Department of Clinical Microbiology and Immunology, College of Pharmacy and Laboratory Medicine, Army Medical University (Third Military Medical University), Chongqing 400000, China; (P.W.); (W.L.); (J.C.); (M.W.); (Y.W.); (J.Y.)
| | - Juanjuan Yue
- Department of Clinical Microbiology and Immunology, College of Pharmacy and Laboratory Medicine, Army Medical University (Third Military Medical University), Chongqing 400000, China; (P.W.); (W.L.); (J.C.); (M.W.); (Y.W.); (J.Y.)
| | - Xuhu Mao
- Department of Clinical Microbiology and Immunology, College of Pharmacy and Laboratory Medicine, Army Medical University (Third Military Medical University), Chongqing 400000, China; (P.W.); (W.L.); (J.C.); (M.W.); (Y.W.); (J.Y.)
- State Key Laboratory of Trauma and Chemical Poisoning, Army Medical University (Third Military Medical University), Chongqing 400000, China
| | - Qian Li
- Department of Clinical Microbiology and Immunology, College of Pharmacy and Laboratory Medicine, Army Medical University (Third Military Medical University), Chongqing 400000, China; (P.W.); (W.L.); (J.C.); (M.W.); (Y.W.); (J.Y.)
- State Key Laboratory of Trauma and Chemical Poisoning, Army Medical University (Third Military Medical University), Chongqing 400000, China
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Jenkins CH, Scott AE, O’Neill PA, Norville IH, Prior JL, Ireland PM. The Arabinose 5-Phosphate Isomerase KdsD Is Required for Virulence in Burkholderia pseudomallei. J Bacteriol 2023; 205:e0003423. [PMID: 37458584 PMCID: PMC10448790 DOI: 10.1128/jb.00034-23] [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: 01/27/2023] [Accepted: 06/06/2023] [Indexed: 08/25/2023] Open
Abstract
Burkholderia pseudomallei is the causative agent of melioidosis, which is endemic primarily in Southeast Asia and northern Australia but is increasingly being seen in other tropical and subtropical regions of the world. Melioidosis is associated with high morbidity and mortality rates, which is mediated by the wide range of virulence factors encoded by B. pseudomallei. These virulence determinants include surface polysaccharides such as lipopolysaccharide (LPS) and capsular polysaccharides (CPS). Here, we investigated a predicted arabinose-5-phosphate isomerase (API) similar to KdsD in B. pseudomallei strain K96243. KdsD is required for the production of the highly conserved 3-deoxy-d-manno-octulosonic acid (Kdo), a key sugar in the core region of LPS. Recombinant KdsD was expressed and purified, and API activity was determined. Although a putative API paralogue (KpsF) is also predicted to be encoded, the deletion of kdsD resulted in growth defects, loss of motility, reduced survival in RAW 264.7 murine macrophages, and attenuation in a BALB/c mouse model of melioidosis. Suppressor mutations were observed during a phenotypic screen for motility, revealing single nucleotide polymorphisms or indels located in the poorly understood CPS type IV cluster. Crucially, suppressor mutations did not result in reversion of attenuation in vivo. This study demonstrates the importance of KdsD for B. pseudomallei virulence and highlights further the complex nature of the polysaccharides it produces. IMPORTANCE The intrinsic resistance of B. pseudomallei to many antibiotics complicates treatment. This opportunistic pathogen possesses a wide range of virulence factors, resulting in severe and potentially fatal disease. Virulence factors as targets for drug development offer an alternative approach to combat pathogenic bacteria. Prior to initiating early drug discovery approaches, it is important to demonstrate that disruption of the target gene will prevent the development of disease. This study highlights the fact that KdsD is crucial for virulence of B. pseudomallei in an animal model of infection and provides supportive phenotypic characterization that builds a foundation for future therapeutic development.
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Affiliation(s)
- Christopher H. Jenkins
- Chemical, Biological and Radiological Division, Defence Science and Technology Laboratory, Salisbury, Wiltshire, United Kingdom
| | - Andrew E. Scott
- Chemical, Biological and Radiological Division, Defence Science and Technology Laboratory, Salisbury, Wiltshire, United Kingdom
| | - Paul A. O’Neill
- University of Exeter Sequencing Service, Exeter, United Kingdom
| | - Isobel H. Norville
- Chemical, Biological and Radiological Division, Defence Science and Technology Laboratory, Salisbury, Wiltshire, United Kingdom
- Biosciences Department, University of Exeter, Exeter, United Kingdom
| | - Joann L. Prior
- Chemical, Biological and Radiological Division, Defence Science and Technology Laboratory, Salisbury, Wiltshire, United Kingdom
- Biosciences Department, University of Exeter, Exeter, United Kingdom
- Southampton General Hospital, Southampton, United Kingdom
| | - Philip M. Ireland
- Chemical, Biological and Radiological Division, Defence Science and Technology Laboratory, Salisbury, Wiltshire, United Kingdom
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Trottmann F, Fiedler J, Ishida K, Ishida-Ito M, Little RF, Hertweck C. Bacterial Pathogen Channels Medium-Sized Fatty Acids into Malleicyprol Biosynthesis. ACS Chem Biol 2023; 18:1557-1563. [PMID: 37319349 DOI: 10.1021/acschembio.3c00188] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 06/17/2023]
Abstract
Bacterial pathogens of the Burkholderia pseudomallei (BP) group cause life-threatening infections in both humans and animals. Critical for the virulence of these often antibiotic-resistant pathogens is the polyketide hybrid metabolite malleicyprol, which features two chains, a short cyclopropanol-substituted chain and a long hydrophobic alkyl chain. The biosynthetic origin of the latter has remained unknown. Here, we report the discovery of novel overlooked malleicyprol congeners with varied chain lengths and identify medium-sized fatty acids as polyketide synthase (PKS) starter units that constitute the hydrophobic carbon tails. Mutational and biochemical analyses show that a designated coenzyme A-independent fatty acyl-adenylate ligase (FAAL, BurM) is essential for recruiting and activating fatty acids in malleicyprol biosynthesis. In vitro reconstitution of the BurM-catalyzed PKS priming reaction and analysis of ACP-bound building blocks reveal a key role of BurM in the toxin assembly. Insights into the function and role of BurM hold promise for the development of enzyme inhibitors as novel antivirulence therapeutics to combat infections with BP pathogens.
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Affiliation(s)
- Felix Trottmann
- Department of Biomolecular Chemistry, Leibniz Institute for Natural Product Research and Infection Biology (HKI), Beutenbergstraße 11a, 07745 Jena, Germany
| | - Jonas Fiedler
- Department of Biomolecular Chemistry, Leibniz Institute for Natural Product Research and Infection Biology (HKI), Beutenbergstraße 11a, 07745 Jena, Germany
| | - Keishi Ishida
- Department of Biomolecular Chemistry, Leibniz Institute for Natural Product Research and Infection Biology (HKI), Beutenbergstraße 11a, 07745 Jena, Germany
| | - Mie Ishida-Ito
- Department of Biomolecular Chemistry, Leibniz Institute for Natural Product Research and Infection Biology (HKI), Beutenbergstraße 11a, 07745 Jena, Germany
| | - Rory F Little
- Department of Biomolecular Chemistry, Leibniz Institute for Natural Product Research and Infection Biology (HKI), Beutenbergstraße 11a, 07745 Jena, Germany
| | - Christian Hertweck
- Department of Biomolecular Chemistry, Leibniz Institute for Natural Product Research and Infection Biology (HKI), Beutenbergstraße 11a, 07745 Jena, Germany
- Natural Product Chemistry, Faculty of Biological Sciences, Friedrich Schiller University Jena, 07743 Jena, Germany
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Ali A, Waris A, Khan MA, Asim M, Khan AU, Khan S, Zeb J. Recent advancement, immune responses, and mechanism of action of various vaccines against intracellular bacterial infections. Life Sci 2023; 314:121332. [PMID: 36584914 DOI: 10.1016/j.lfs.2022.121332] [Citation(s) in RCA: 9] [Impact Index Per Article: 9.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/18/2022] [Revised: 12/20/2022] [Accepted: 12/23/2022] [Indexed: 12/29/2022]
Abstract
Emerging and re-emerging bacterial infections are a serious threat to human and animal health. Extracellular bacteria are free-living, while facultative intracellular bacteria replicate inside eukaryotic host cells. Many serious human illnesses are now known to be caused by intracellular bacteria such as Salmonella enterica, Escherichia coli, Staphylococcus aureus, Rickettsia massiliae, Chlamydia species, Brucella abortus, Mycobacterium tuberculosis and Listeria monocytogenes, which result in substantial morbidity and mortality. Pathogens like Mycobacterium, Brucella, MRSA, Shigella, Listeria, and Salmonella can infiltrate and persist in mammalian host cells, particularly macrophages, where they proliferate and establish a repository, resulting in chronic and recurrent infections. The current treatment for these bacteria involves the application of narrow-spectrum antibiotics. FDA-approved vaccines against obligate intracellular bacterial infections are lacking. The development of vaccines against intracellular pathogenic bacteria are more difficult because host defense against these bacteria requires the activation of the cell-mediated pathway of the immune system, such as CD8+ T and CD4+ T. However, different types of vaccines, including live, attenuated, subunit, killed whole cell, nano-based and DNA vaccines are currently in clinical trials. Substantial development has been made in various vaccine strategies against intracellular pathogenic bacteria. This review focuses on the mechanism of intracellular bacterial infection, host immune response, and recent advancements in vaccine development strategies against various obligate intracellular bacterial infections.
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Affiliation(s)
- Asmat Ali
- Department of Biotechnology and Genetic Engineering, Hazara University Mansehra, Pakistan
| | - Abdul Waris
- Department of Biomedical Sciences, City University of Hong Kong, Hong Kong.
| | - Muhammad Ajmal Khan
- Division of Life Sciences, Center for Cancer Research and State Key Laboratory of Molecular Neurosciences, The Hong Kong University of Science and Technology, Hong Kong
| | - Muhammad Asim
- Department of Biomedical Sciences, City University of Hong Kong, Hong Kong
| | - Atta Ullah Khan
- CAS Key Laboratory of Standardization and Measurement for Nanotechnology, CAS Center for Excellence in Nanoscience, National Center for Nanoscience and Technology, China
| | - Sahrish Khan
- Department of Biotechnology, Quaid-i-Azam University, Islamabad, Pakistan
| | - Jehan Zeb
- Department of Infectious Diseases and Public Health, City University of Hong Kong, Hong Kong
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Paauw A, Scholz HC, Mars-Groenendijk RH, Dekker LJM, Luider TM, van Leeuwen HC. Expression of virulence and antimicrobial related proteins in Burkholderia mallei and Burkholderia pseudomallei. PLoS Negl Trop Dis 2023; 17:e0011006. [PMID: 36607891 PMCID: PMC9821509 DOI: 10.1371/journal.pntd.0011006] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/05/2021] [Accepted: 12/06/2022] [Indexed: 01/07/2023] Open
Abstract
BACKGROUND Burkholderia mallei and Burkholderia pseudomallei are both potential biological threat agents. Melioidosis caused by B. pseudomallei is endemic in Southeast Asia and Northern Australia, while glanders caused by B. mallei infections are rare. Here we studied the proteomes of different B. mallei and B. pseudomallei isolates to determine species specific characteristics. METHODS The expressed proteins of 5 B. mallei and 6 B. pseudomallei strains were characterized using liquid chromatography high-resolution tandem mass spectrometry (LC-HRMS/MS). Subsequently, expression of potential resistance and virulence related characteristics were analyzed and compared. RESULTS Proteome analysis can be used for the identification of B. mallei and B. pseudomallei. Both species were identified based on >60 discriminative peptides. Expression of proteins potentially involved in antimicrobial resistance, AmrAB-OprA, BpeAB-OprB, BpeEF-OprC, PenA as well as several other efflux pump related proteins and putative β-lactamases was demonstrated. Despite, the fact that efflux pump BpeAB-OprB was expressed in all isolates, no clear correlation with an antimicrobial phenotype and the efflux-pump could be established. Also consistent with the phenotypes, no amino acid mutations in PenA known to result in β-lactam resistance could be identified. In all studied isolates, the expression of virulence (related) factors Capsule-1 and T2SS was demonstrated. The expression of T6SS-1 was demonstrated in all 6 B. pseudomallei isolates and in 2 of the 5 B. mallei isolates. In all, except one B. pseudomallei isolate, poly-beta-1,6 N-acetyl-D-glucosamine export porin (Pga), important for biofilm formation, was detected, which were absent in the proteomes of B. mallei. Siderophores, iron binding proteins, malleobactin and malleilactone are possibly expressed in both species under standard laboratory growth conditions. Expression of multiple proteins from both the malleobactin and malleilactone polyketide synthase (PKS) and non-ribosomal peptide synthetase (NRPS) clusters was demonstrated in both species. All B. pseudomallei expressed at least seven of the nine proteins of the bactobolin synthase cluster (bactobolin, is a ribosome targeting antibiotic), while only in one B. mallei isolate expression of two proteins of this synthase cluster was identified. CONCLUSIONS Analyzing the expressed proteomes revealed differences between B. mallei and B. pseudomallei but also between isolates from the same species. Proteome analysis can be used not only to identify B. mallei and B. pseudomallei but also to characterize the presence of important factors that putatively contribute to the pathogenesis of B. mallei and B. pseudomallei.
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Affiliation(s)
- Armand Paauw
- Netherlands Organization for Applied Scientific Research TNO, Department of CBRN Protection, Rijswijk, The Netherlands
- * E-mail:
| | - Holger C. Scholz
- Centre for Biological Threats and Special Pathogens, Highly Pathogenic Microorganisms (ZBS 2), Robert Koch Institute, Berlin, Germany
| | - Roos H. Mars-Groenendijk
- Netherlands Organization for Applied Scientific Research TNO, Department of CBRN Protection, Rijswijk, The Netherlands
| | | | - Theo M. Luider
- Department of Neurology, Erasmus MC, Rotterdam, The Netherlands
| | - Hans C. van Leeuwen
- Netherlands Organization for Applied Scientific Research TNO, Department of CBRN Protection, Rijswijk, The Netherlands
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Wong YC, Naeem R, Abd El Ghany M, Hoh CC, Pain A, Nathan S. Genome-wide transposon mutagenesis analysis of Burkholderia pseudomallei reveals essential genes for in vitro and in vivo survival. Front Cell Infect Microbiol 2022; 12:1062682. [PMID: 36619746 PMCID: PMC9816413 DOI: 10.3389/fcimb.2022.1062682] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/06/2022] [Accepted: 12/05/2022] [Indexed: 12/24/2022] Open
Abstract
Introduction Burkholderia pseudomallei, a soil-dwelling microbe that infects humans and animals is the cause of the fatal disease melioidosis. The molecular mechanisms that underlie B. pseudomallei's versatility to survive within a broad range of environments are still not well defined. Methods We used the genome-wide screening tool TraDIS (Transposon Directed Insertion-site Sequencing) to identify B. pseudomallei essential genes. Transposon-flanking regions were sequenced and gene essentiality was assessed based on the frequency of transposon insertions within each gene. Transposon mutants were grown in LB and M9 minimal medium to determine conditionally essential genes required for growth under laboratory conditions. The Caenorhabditis elegans infection model was used to assess genes associated with in vivo B. pseudomallei survival. Transposon mutants were fed to the worms, recovered from worm intestines, and sequenced. Two selected mutants were constructed and evaluated for the bacteria's ability to survive and proliferate in the nematode intestinal lumen. Results Approximately 500,000 transposon-insertion mutants of B. pseudomallei strain R15 were generated. A total of 848,811 unique transposon insertion sites were identified in the B. pseudomallei R15 genome and 492 genes carrying low insertion frequencies were predicted to be essential. A total of 96 genes specifically required to support growth under nutrient-depleted conditions were identified. Genes most likely to be involved in B. pseudomallei survival and adaptation in the C. elegans intestinal lumen, were identified. When compared to wild type B. pseudomallei, a Tn5 mutant of bpsl2988 exhibited reduced survival in the worm intestine, was attenuated in C. elegans killing and showed decreased colonization in the organs of infected mice. Discussion The B. pseudomallei conditional essential proteins should provide further insights into the bacteria's niche adaptation, pathogenesis, and virulence.
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Affiliation(s)
- Yee-Chin Wong
- Department of Biological Sciences and Biotechnology, Faculty of Science and Technology, Universiti Kebangsaan Malaysia, Bangi, Malaysia
| | - Raeece Naeem
- Bioscience program, Biological and Environmental Sciences and Engineering Division, King Abdullah University of Science and Technology, Jeddah, Saudi Arabia
| | - Moataz Abd El Ghany
- Bioscience program, Biological and Environmental Sciences and Engineering Division, King Abdullah University of Science and Technology, Jeddah, Saudi Arabia,School of Public Health, The University of Sydney, Sydney, NSW, Australia,Centre for Infectious Disease and Microbiology, The Westmead Institute for Medical Research, Sydney, NSW, Australia,Sydney Institute for Infectious Diseases, The University of Sydney, Sydney, NSW, Australia
| | | | - Arnab Pain
- Bioscience program, Biological and Environmental Sciences and Engineering Division, King Abdullah University of Science and Technology, Jeddah, Saudi Arabia
| | - Sheila Nathan
- Department of Biological Sciences and Biotechnology, Faculty of Science and Technology, Universiti Kebangsaan Malaysia, Bangi, Malaysia,*Correspondence: Sheila Nathan,
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10
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Ghimire J, Guha S, Nelson BJ, Morici LA, Wimley WC. The Remarkable Innate Resistance of Burkholderia bacteria to Cationic Antimicrobial Peptides: Insights into the Mechanism of AMP Resistance. J Membr Biol 2022; 255:503-511. [PMID: 35435452 PMCID: PMC9576820 DOI: 10.1007/s00232-022-00232-2] [Citation(s) in RCA: 4] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/16/2022] [Accepted: 03/24/2022] [Indexed: 12/29/2022]
Abstract
Gram-negative bacteria belonging to the genus Burkholderia are remarkably resistant to broad-spectrum, cationic, antimicrobial peptides (AMPs). It has been proposed that this innate resistance is related to changes in the outer membrane lipopolysaccharide (OM LPS), including the constitutive, essential modification of outer membrane Lipid A phosphate groups with cationic 4-amino-4-deoxy-arabinose. This modification reduces the overall negative charge on the OM LPS which may change the OM structure and reduce the binding, accumulation, and permeation of cationic AMPs. Similarly, the Gram-negative pathogen Pseudomonas aeruginosa can quickly become resistant to many AMPs by multiple mechanisms, frequently, including activation of the arn operon, which leads, transiently, to the same modification of Lipid A. We recently discovered a set of synthetically evolved AMPs that do not invoke any resistance in P. aeruginosa over multiple passages and thus are apparently not inhibited by aminorabinosylation of Lipid A in P. aeruginosa. Here we test these resistance-avoiding peptides, within a set of 18 potent AMPs, against Burkholderia thailandensis. We find that none of the AMPs tested have measurable activity against B. thailandensis. Some were inactive at concentrations as high as 150 μM, despite all having sterilizing activity at ≤ 10 μM against a panel of common, human bacterial pathogens, including P. aeruginosa. We speculate that the constitutive modification of Lipid A in members of the Burkholderia genus is only part of a broader set of modifications that change the architecture of the OM to provide such remarkable levels of resistance to cationic AMPs.
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Affiliation(s)
- Jenisha Ghimire
- Department of Biochemistry and Molecular Biology, Tulane University School of Medicine, New Orleans, LA, 70112
| | - Shantanu Guha
- Department of Biochemistry and Molecular Biology, Tulane University School of Medicine, New Orleans, LA, 70112
| | - Benjamin J. Nelson
- Department of Biochemistry and Molecular Biology, Tulane University School of Medicine, New Orleans, LA, 70112
| | - Lisa A. Morici
- Department of Microbiology and Immunology, Tulane University School of Medicine, New Orleans, LA, 70112
| | - William C. Wimley
- Department of Biochemistry and Molecular Biology, Tulane University School of Medicine, New Orleans, LA, 70112,To whom correspondence should be addressed at
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11
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Development of Melioidosis Subunit Vaccines Using an Enzymatically Inactive Burkholderia pseudomallei AhpC. Infect Immun 2022; 90:e0022222. [PMID: 35862715 PMCID: PMC9387246 DOI: 10.1128/iai.00222-22] [Citation(s) in RCA: 8] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/21/2023] Open
Abstract
Burkholderia pseudomallei, the causative agent of melioidosis, is a facultative intracellular, Gram-negative pathogen that is highly infectious via the respiratory route and can cause severe, debilitating, and often fatal diseases in humans and animals. At present, no licensed vaccines for immunization against this CDC Tier 1 select agent exist. Studies in our lab have previously demonstrated that subunit vaccine formulations consisting of a B. pseudomallei capsular polysaccharide (CPS)-based glycoconjugate (CPS-CRM197) combined with hemolysin-coregulated protein (Hcp1) provided C57BL/6 mice with high-level protection against an acute inhalational challenge of B. pseudomallei. In this study, we evaluated the immunogenicity and protective capacity of B. pseudomallei alkyl hydroperoxide reductase subunit C (AhpC) in combination with CPS-CRM197. AhpC is a peroxiredoxin involved in oxidative stress reduction and is a potential protective antigen. To facilitate our studies and maximize safety in animals, recombinant B. pseudomallei AhpC harboring an active site mutation (AhpCC57G) was expressed in Escherichia coli and purified using tandem nickel-cobalt affinity chromatography. Immunization of C57BL/6 mice with CPS-CRM197 combined with AhpCC57G stimulated high-titer IgG responses against the CPS component of the glycoconjugate as well as stimulated high-titer IgG and robust interferon gamma (IFN-γ)-, interleukin-5 (IL-5)-, and IL-17-secreting T cell responses against AhpCC57G. When challenged via an inhalational route with a high dose (~27 50% lethal doses [LD50s]) of B. pseudomallei, 70% of the immunized mice survived 35 days postchallenge. Collectively, our findings demonstrate that AhpCC57G is a potent activator of cellular and humoral immune responses and may be a promising candidate to include in future melioidosis subunit vaccines.
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12
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A c-di-GMP Signaling Cascade Controls Motility, Biofilm Formation, and Virulence in Burkholderia thailandensis. Appl Environ Microbiol 2022; 88:e0252921. [PMID: 35323023 DOI: 10.1128/aem.02529-21] [Citation(s) in RCA: 4] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
As a key bacterial second messenger, cyclic di-GMP (c-di-GMP) regulates various physiological processes, such as motility, biofilm formation, and virulence. Cellular c-di-GMP levels are regulated by the opposing activities of diguanylate cyclases (DGCs) and phosphodiesterases (PDEs). Beyond that, the enzymatic activities of c-di-GMP metabolizing proteins are controlled by a variety of extracellular signals and intracellular physiological conditions. Here, we report that pdcA (BTH_II2363), pdcB (BTH_II2364), and pdcC (BTH_II2365) are cotranscribed in the same operon and are involved in a regulatory cascade controlling the cellular level of c-di-GMP in Burkholderia thailandensis. The GGDEF domain-containing protein PdcA was found to be a DGC that modulates biofilm formation, motility, and virulence in B. thailandensis. Moreover, the DGC activity of PdcA was inhibited by phosphorylated PdcC, a single-domain response regulator composed of only the phosphoryl-accepting REC domain. The phosphatase PdcB affects the function of PdcA by dephosphorylating PdcC. The observation that homologous operons of pdcABC are widespread among betaproteobacteria and gammaproteobacteria suggests a general mechanism by which the intracellular concentration of c-di-GMP is modulated to coordinate bacterial behavior and virulence. IMPORTANCE The transition from planktonic cells to biofilm cells is a successful strategy adopted by bacteria to survive in diverse environments, while the second messenger c-di-GMP plays an important role in this process. Cellular c-di-GMP levels are mainly controlled by modulating the activity of c-di-GMP-metabolizing proteins via the sensory domains adjacent to their enzymatic domains. However, in most cases how c-di-GMP-metabolizing enzymes are modulated by their sensory domains remains unclear. Here, we reveal a new c-di-GMP signaling cascade that regulates motility, biofilm formation, and virulence in B. thailandensis. While pdcA, pdcB, and pdcC constitute an operon, the phosphorylated PdcC binds the PAS sensory domain of PdcA to inhibit its DGC activity, with PdcB dephosphorylating PdcC to derepress the activity of PdcA. We also show this c-di-GMP regulatory model is widespread in the phylum Proteobacteria. Our study expands the current knowledge of how bacteria regulate intracellular c-di-GMP levels.
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13
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Kaewpan A, Duangurai T, Rungruengkitkun A, Muangkaew W, Kanjanapruthipong T, Jitprasutwit N, Ampawong S, Sukphopetch P, Chantratita N, Pumirat P. Burkholderia pseudomallei pathogenesis in human skin fibroblasts: A Bsa type III secretion system is involved in the invasion, multinucleated giant cell formation, and cellular damage. PLoS One 2022; 17:e0261961. [PMID: 35113856 PMCID: PMC8812868 DOI: 10.1371/journal.pone.0261961] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/07/2021] [Accepted: 12/14/2021] [Indexed: 11/19/2022] Open
Abstract
Burkholderia pseudomallei-a causative agent of melioidosis that is endemic in Southeast Asia and Northern Australia-is a Gram-negative bacterium transmitted to humans via inhalation, inoculation through skin abrasions, and ingestion. Melioidosis causes a range of clinical presentations including skin infection, pneumonia, and septicemia. Despite skin infection being one of the clinical symptoms of melioidosis, the pathogenesis of B. pseudomallei in skin fibroblasts has not yet been elucidated. In this study, we investigated B. pseudomallei pathogenesis in the HFF-1 human skin fibroblasts. On the basis of co-culture assays between different B. pseudomallei clinical strains and the HFF-1 human skin fibroblasts, we found that all B. pseudomallei strains have the ability to mediate invasion, intracellular replication, and multinucleated giant cell (MNGC) formation. Furthermore, all strains showed a significant increase in cytotoxicity in human fibroblasts, which coincides with the augmented expression of matrix metalloproteinase-2. Using B. pseudomallei mutants, we showed that the B. pseudomallei Bsa type III secretion system (T3SS) contributes to skin fibroblast pathogenesis, but O-polysaccharide, capsular polysaccharide, and short-chain dehydrogenase metabolism do not play a role in this process. Taken together, our findings reveal a probable connection for the Bsa T3SS in B. pseudomallei infection of skin fibroblasts, and this may be linked to the pathogenesis of cutaneous melioidosis.
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Affiliation(s)
- Anek Kaewpan
- Department of Microbiology and Immunology, Faculty of Tropical Medicine, Mahidol University, Bangkok, Thailand
| | - Taksaon Duangurai
- Department of Companion Animal Clinical Sciences, Faculty of Veterinary Medicine, Kasetsart University, Bangkok, Thailand
| | - Amporn Rungruengkitkun
- Department of Microbiology and Immunology, Faculty of Tropical Medicine, Mahidol University, Bangkok, Thailand
| | - Watcharamat Muangkaew
- Department of Microbiology and Immunology, Faculty of Tropical Medicine, Mahidol University, Bangkok, Thailand
| | - Tapanee Kanjanapruthipong
- Department of Tropical Pathology, Faculty of Tropical Medicine, Mahidol University, Bangkok, Thailand
| | - Niramol Jitprasutwit
- Department of Immunology, Faculty of Medicine Siriraj Hospital, Mahidol University, Bangkok, Thailand
| | - Sumate Ampawong
- Department of Tropical Pathology, Faculty of Tropical Medicine, Mahidol University, Bangkok, Thailand
| | - Passanesh Sukphopetch
- Department of Microbiology and Immunology, Faculty of Tropical Medicine, Mahidol University, Bangkok, Thailand
| | - Narisara Chantratita
- 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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14
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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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15
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Prabhu RA, Shaw T, Rao IR, Kalwaje Eshwara V, Nagaraju SP, Shenoy SV, Mukhopadhyay C. Acute kidney injury and its outcomes in melioidosis. J Nephrol 2021; 34:1941-1948. [PMID: 33515381 PMCID: PMC8610944 DOI: 10.1007/s40620-021-00970-x] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/23/2020] [Accepted: 01/04/2021] [Indexed: 10/25/2022]
Abstract
BACKGROUND Melioidosis is a potentially fatal tropical infection caused by Burkholderia pseudomallei. Kidney involvement is possible, but has not been well described. AIM This study aimed to assess the risk of acute kidney injury (AKI) and its outcomes in melioidosis. METHODS A retrospective observational cohort study was performed. Case records of consecutive patients with culture-confirmed melioidosis, observed from January 1st, 2012 through December 31st, 2019 were analysed for demographics, presence of comorbidities, including chronic kidney disease (CKD), diabetes mellitus (DM), and presence of bacteraemia, sepsis, shock, AKI, and urinary abnormalities. The outcomes we studied were: mortality, need for hospitalisation in an intensive care unit (ICU), duration of hospitalization. We then compared the outcomes between patients with and without AKI. RESULTS Of 164 patients, AKI was observed in 59 (35.98%), and haemodialysis was required in eight (13.56%). In the univariate analysis, AKI was associated with CKD (OR 5.83; CI 1.140-29.90, P = 0.03), bacteraemia (OR 8.82; CI 3.67-21.22, P < 0.001) and shock (OR 3.75; CI 1.63-8.65, P = 0.04). In the multivariate analysis, CKD (adjusted OR 10.68; 95% CI 1.66-68.77; P = 0.013) and bacteraemia (adjusted OR 8.22; 95% CI 3.15-21.47, P < 0.001) predicted AKI. AKI was associated with a greater need for ICU care (37.3% vs. 13.3%, P = 0.001), and mortality (32.2% vs. 5.7%, P < 0.001). Mortality increased with increasing AKI stage, i.e. stage 1 (OR 3.52, CI 0.9-13.7, P = 0.07), stage 2 (OR 6.79, CI 1.92-24, P = 0.002) and stage 3 (OR 17.8, CI 5.05-62.8, P < 0.001), however kidney function recovered in survivors. Hyponatremia was observed in 138 patients (84.15%) and isolated urinary abnormalities were seen in 31(18.9%). CONCLUSIONS AKI is frequent in melioidosis and occurred in 35.9% of our cases. Hyponatremia is likewise common. AKI was predicted by bacteraemia and CKD, and was associated with higher mortality and need for ICU care; however kidney function recovery was observed in survivors.
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Affiliation(s)
- Ravindra Attur Prabhu
- Department of Nephrology, Kasturba Medical College, Manipal, Manipal Academy of Higher Education, Manipal, Udupi, 576104, Karnataka, India.
| | - Tushar Shaw
- Department of Microbiology, Kasturba Medical College, Manipal, Manipal Academy of Higher Education, Manipal, Karnataka, India
| | - Indu Ramachandra Rao
- Department of Nephrology, Kasturba Medical College, Manipal, Manipal Academy of Higher Education, Manipal, Udupi, 576104, Karnataka, India
| | - Vandana Kalwaje Eshwara
- Department of Microbiology, Kasturba Medical College, Manipal, Manipal Academy of Higher Education, Manipal, Karnataka, India
| | - Shankar Prasad Nagaraju
- Department of Nephrology, Kasturba Medical College, Manipal, Manipal Academy of Higher Education, Manipal, Udupi, 576104, Karnataka, India
| | - Srinivas Vinayak Shenoy
- Department of Nephrology, Kasturba Medical College, Manipal, Manipal Academy of Higher Education, Manipal, Udupi, 576104, Karnataka, India
| | - Chiranjay Mukhopadhyay
- Department of Microbiology, Kasturba Medical College, Manipal, Manipal Academy of Higher Education, Manipal, Karnataka, India
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16
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Recent Progress in Shigella and Burkholderia pseudomallei Vaccines. Pathogens 2021; 10:pathogens10111353. [PMID: 34832508 PMCID: PMC8621228 DOI: 10.3390/pathogens10111353] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/15/2021] [Revised: 10/15/2021] [Accepted: 10/18/2021] [Indexed: 12/28/2022] Open
Abstract
Significant advancement has been made in the development of vaccines against bacterial pathogens. However, several roadblocks have been found during the evaluation of vaccines against intracellular bacterial pathogens. Therefore, new lessons could be learned from different vaccines developed against unrelated intracellular pathogens. Bacillary dysentery and melioidosis are important causes of morbidity and mortality in developing nations, which are caused by the intracellular bacteria Shigella and Burkholderia pseudomallei, respectively. Although the mechanisms of bacterial infection, dissemination, and route of infection do not provide clues about the commonalities of the pathogenic infectious processes of these bacteria, a wide variety of vaccine platforms recently evaluated suggest that in addition to the stimulation of antibodies, identifying protective antigens and inducing T cell responses are some additional required elements to induce effective protection. In this review, we perform a comparative evaluation of recent candidate vaccines used to combat these two infectious agents, emphasizing the common strategies that can help investigators advance effective and protective vaccines to clinical trials.
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17
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Monoclonal Antibodies Opsonize Burkholderia spp. and Reduce Intracellular Actin Tail Formation in a Macrophage Infection Assay. J Bacteriol 2021; 203:e0024421. [PMID: 34460311 PMCID: PMC8508110 DOI: 10.1128/jb.00244-21] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
Melioidosis is a neglected tropical disease caused by the bacterium Burkholderia pseudomallei. The bacterium is intrinsically resistant to various antibiotics, and melioidosis is therefore difficult to treat successfully without a relapse in infection. B. pseudomallei is an intracellular pathogen and therefore, to eradicate the infection, antimicrobials must be able to access bacteria in an intracellular niche. This study assessed the ability of a panel of monoclonal antibodies (MAbs) to opsonize Burkholderia species and determine the effect that each antibody has on bacterial virulence in vitro. Murine macrophage infection assays demonstrated that monoclonal antibodies against the capsule of B. pseudomallei are opsonizing. Furthermore, one of these monoclonal antibodies reduced bacterial actin tail formation in our in vitro assays, indicating that antibodies could reduce the intracellular spread of Burkholderia thailandensis. The data presented in this paper demonstrate that monoclonal antibodies are opsonizing and can decrease bacterial actin tail formation, thus decreasing their intracellular spread. These data have informed selection of an antibody for development of an antibody-antibiotic conjugate (AAC) for melioidosis. IMPORTANCE Melioidosis is difficult to treat successfully due to the causal bacterium being resistant to many classes of antibiotics, therefore limiting available therapeutic options. New and improved therapies are urgently required to treat this disease. Here, we have investigated the potential of monoclonal antibodies to target this intracellular pathogen. We have demonstrated that monoclonal antibodies can target the bacterium, increase uptake into macrophages, and reduce actin tail formation required by the bacterium for spread between cells. Through targeting the bacterium with antibodies, we hope to disarm the pathogen, reducing the spread of infection. Ultimately, we aim to use an opsonizing antibody to deliver antibiotics intracellularly by developing an antibody-antibiotic conjugate therapeutic for melioidosis.
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18
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Mariappan V, Vellasamy KM, Barathan M, Girija ASS, Shankar EM, Vadivelu J. Hijacking of the Host's Immune Surveillance Radars by Burkholderia pseudomallei. Front Immunol 2021; 12:718719. [PMID: 34456925 PMCID: PMC8384953 DOI: 10.3389/fimmu.2021.718719] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/01/2021] [Accepted: 07/12/2021] [Indexed: 11/20/2022] Open
Abstract
Burkholderia pseudomallei (B. pseudomallei) causes melioidosis, a potentially fatal disease for which no licensed vaccine is available thus far. The host-pathogen interactions in B. pseudomallei infection largely remain the tip of the iceberg. The pathological manifestations are protean ranging from acute to chronic involving one or more visceral organs leading to septic shock, especially in individuals with underlying conditions similar to COVID-19. Pathogenesis is attributed to the intracellular ability of the bacterium to ‘step into’ the host cell’s cytoplasm from the endocytotic vacuole, where it appears to polymerize actin filaments to spread across cells in the closer vicinity. B. pseudomallei effectively evades the host’s surveillance armory to remain latent for prolonged duration also causing relapses despite antimicrobial therapy. Therefore, eradication of intracellular B. pseudomallei is highly dependent on robust cellular immune responses. However, it remains ambiguous why certain individuals in endemic areas experience asymptomatic seroconversion, whereas others succumb to sepsis-associated sequelae. Here, we propose key insights on how the host’s surveillance radars get commandeered by B. pseudomallei.
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Affiliation(s)
- Vanitha Mariappan
- Center for Toxicology and Health Risk Studies, Faculty of Health Sciences, Universiti Kebangsaan Malaysia, Kuala Lumpur, Malaysia
| | - Kumutha Malar Vellasamy
- Department of Medical Microbiology, Faculty of Medicine, Universiti Malaya, Kuala Lumpur, Malaysia
| | - Muttiah Barathan
- Department of Medical Microbiology, Faculty of Medicine, Universiti Malaya, Kuala Lumpur, Malaysia
| | - A S Smiline Girija
- Department of Microbiology, Saveetha Dental College and Hospitals, Saveetha Institute of Medical and Technical Sciences (SIMATS), Chennai, India
| | - Esaki M Shankar
- Infection Biology, Department of Life Sciences, Central University of Tamil Nadu, Thiruvarur, India
| | - Jamuna Vadivelu
- Department of Medical Microbiology, Faculty of Medicine, Universiti Malaya, Kuala Lumpur, Malaysia
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19
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Shropshire H, Jones RA, Aguilo-Ferretjans MM, Scanlan DJ, Chen Y. Proteomics insights into the Burkholderia cenocepacia phosphorus stress response. Environ Microbiol 2021; 23:5069-5086. [PMID: 33684254 DOI: 10.1111/1462-2920.15451] [Citation(s) in RCA: 12] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/21/2020] [Accepted: 03/02/2021] [Indexed: 11/26/2022]
Abstract
The Burkholderia cepacia complex is a group of Burkholderia species that are opportunistic pathogens causing high mortality rates in patients with cystic fibrosis. An environmental stress often encountered by these soil-dwelling and pathogenic bacteria is phosphorus limitation, an essential element for cellular processes. Here, we describe cellular and extracellular proteins differentially regulated between phosphate-deplete (0 mM, no added phosphate) and phosphate-replete (1 mM) growth conditions using a comparative proteomics (LC-MS/MS) approach. We observed a total of 128 and 65 unique proteins were downregulated and upregulated respectively, in the B. cenocepacia proteome. Of those downregulated proteins, many have functions in amino acid transport/metabolism. We have identified 24 upregulated proteins that are directly/indirectly involved in inorganic phosphate or organic phosphorus acquisition. Also, proteins involved in virulence and antimicrobial resistance were differentially regulated, suggesting B. cenocepacia experiences a dramatic shift in metabolism under these stress conditions. Overall, this study provides a baseline for further research into the biology of Burkholderia in response to phosphorus stress.
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Affiliation(s)
- Holly Shropshire
- BBSRC Midlands Integrative Biosciences Training Partnership, University of Warwick, Coventry, CV4 7AL, UK.,School of Life Sciences, University of Warwick, Coventry, CV4 7AL, UK
| | - Rebekah A Jones
- School of Life Sciences, University of Warwick, Coventry, CV4 7AL, UK
| | | | - David J Scanlan
- School of Life Sciences, University of Warwick, Coventry, CV4 7AL, UK
| | - Yin Chen
- School of Life Sciences, University of Warwick, Coventry, CV4 7AL, UK
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20
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Burkholderia pseudomallei OMVs derived from infection mimicking conditions elicit similar protection to a live-attenuated vaccine. NPJ Vaccines 2021; 6:18. [PMID: 33514749 PMCID: PMC7846723 DOI: 10.1038/s41541-021-00281-z] [Citation(s) in RCA: 23] [Impact Index Per Article: 7.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/30/2020] [Accepted: 01/07/2021] [Indexed: 02/07/2023] Open
Abstract
Burkholderia pseudomallei is a Gram-negative, facultative intracellular bacillus that causes the disease melioidosis. B. pseudomallei expresses a number of proteins that contribute to its intracellular survival in the mammalian host. We previously demonstrated that immunization with OMVs derived from B. pseudomallei grown in nutrient-rich media protects mice against lethal disease. Here, we evaluated if OMVs derived from B. pseudomallei grown under macrophage-mimicking growth conditions could be enriched with intracellular-stage proteins in order to improve the vaccine. We show that OMVs produced in this manner (M9 OMVs) contain proteins associated with intracellular survival yet are non-toxic to living cells. Immunization of mice provides significant protection against pulmonary infection similar to that achieved with a live attenuated vaccine and is associated with increased IgG, CD4+, and CD8+ T cells. OMVs possess inherent adjuvanticity and drive DC activation and maturation. These results indicate that M9 OMVs constitute a new promising vaccine against melioidosis.
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21
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Dyke JS, Huertas-Diaz MC, Michel F, Holladay NE, Hogan RJ, He B, Lafontaine ER. The Peptidoglycan-associated lipoprotein Pal contributes to the virulence of Burkholderia mallei and provides protection against lethal aerosol challenge. Virulence 2020; 11:1024-1040. [PMID: 32799724 PMCID: PMC7567441 DOI: 10.1080/21505594.2020.1804275] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/14/2020] [Revised: 07/09/2020] [Accepted: 07/19/2020] [Indexed: 11/07/2022] Open
Abstract
BURKHOLDERIA MALLEI is a highly pathogenic bacterium that causes the fatal zoonosis glanders. The organism specifies multiple membrane proteins, which represent prime targets for the development of countermeasures given their location at the host-pathogen interface. We investigated one of these proteins, Pal, and discovered that it is involved in the ability of B. mallei to resist complement-mediated killing and replicate inside host cells in vitro, is expressed in vivo and induces antibodies during the course of infection, and contributes to virulence in a mouse model of aerosol infection. A mutant in the pal gene of the B. mallei wild-type strain ATCC 23344 was found to be especially attenuated, as BALB/c mice challenged with the equivalent of 5,350 LD50 completely cleared infection. Based on these findings, we tested the hypothesis that a vaccine containing the Pal protein elicits protective immunity against aerosol challenge. To achieve this, the pal gene was cloned in the vaccine vector Parainfluenza Virus 5 (PIV5) and mice immunized with the virus were infected with a lethal dose of B. mallei. These experiments revealed that a single dose of PIV5 expressing Pal provided 80% survival over a period of 40 days post-challenge. In contrast, only 10% of mice vaccinated with a PIV5 control virus construct survived infection. Taken together, our data establish that the Peptidoglycan-associated lipoprotein Pal is a critical virulence determinant of B. mallei and effective target for developing a glanders vaccine.
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Affiliation(s)
- Jeremy S. Dyke
- Department of Infectious Diseases, University of Georgia College of Veterinary Medicine, Athens, GA, USA
| | | | - Frank Michel
- Department of Veterinary Biosciences and Diagnostic Imaging, University of Georgia College of Veterinary Medicine, Athens, GA, USA
| | - Nathan E. Holladay
- Department of Veterinary Biosciences and Diagnostic Imaging, University of Georgia College of Veterinary Medicine, Athens, GA, USA
| | - Robert J. Hogan
- Department of Infectious Diseases, University of Georgia College of Veterinary Medicine, Athens, GA, USA
- Department of Veterinary Biosciences and Diagnostic Imaging, University of Georgia College of Veterinary Medicine, Athens, GA, USA
| | - Biao He
- Department of Infectious Diseases, University of Georgia College of Veterinary Medicine, Athens, GA, USA
| | - Eric R. Lafontaine
- Department of Infectious Diseases, University of Georgia College of Veterinary Medicine, Athens, GA, USA
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Testamenti VA, Noviana R, Iskandriati D, Norris MH, Jiranantasak T, Tuanyok A, Wahyudi AT, Sajuthi D, Pamungkas J. Humoral Immune Responses to Burkholderia pseudomallei Antigens in Captive and Wild Macaques in the Western Part of Java, Indonesia. Vet Sci 2020; 7:E153. [PMID: 33050516 PMCID: PMC7712568 DOI: 10.3390/vetsci7040153] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/23/2020] [Revised: 10/05/2020] [Accepted: 10/06/2020] [Indexed: 02/07/2023] Open
Abstract
Burkholderia pseudomallei, the Gram-negative bacterium which causes melioidosis, is a threat to human and a wide range of animal species. There is an increased concern of melioidosis in Indonesian primate facilities, especially following case reports of fatal melioidosis in captive macaques and orangutans. Our preliminary serosurveillance of immunoglobulin G (IgG) to B. pseudomallei lipopolysaccharide showed that a significant number of captive and wild macaques in the western part of Java, Indonesia, have been exposed to B. pseudomallei. To better characterize the humoral immune response in those animals, a panel of assays were conducted on the same blood plasma specimens that were taken from 182 cynomolgus macaques (M. fascicularis) and 88 pig-tailed macaques (M. nemestrina) reared in captive enclosures and wild habitats in the western part of Java, Indonesia. The enzyme-linked immunosorbent assays (ELISAs) in this study were conducted to detect IgG against B. pseudomallei proteins; alkyl hydroperoxide reductase subunit C (AhpC), hemolysin-coregulated protein (Hcp1), and putative outer membrane porin protein (OmpH). The performances of those immunoassays were compared to ELISA against B. pseudomallei LPS, which has been conducted previously. Seropositivity to at least one assay was 76.4% (139/182) and 13.6% (12/88) in cynomolgus macaques and pig-tailed macaques, respectively. Analysis of demographic factors showed that species and primate facility were significant factors. Cynomolgus macaques had higher probability of exposure to B. pseudomallei. Moreover, macaques in Jonggol facility also had higher probability, compared to macaques in other facilities. There were no statistical associations between seropositivity with other demographic factors such as sex, age group, and habitat type. There were strong positive correlations between the absorbance results of AhpC, HcpI, and OmpH assays, but not with LPS assay. Our analysis suggested that Hcp1 assay would complement LPS assay in melioidosis serosurveillance in macaques.
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Affiliation(s)
- Vincentius Arca Testamenti
- Primatology Study Program, Graduate School of IPB University, Bogor, Jawa Barat 16128, Indonesia; (D.I.); (D.S.)
| | | | - Diah Iskandriati
- Primatology Study Program, Graduate School of IPB University, Bogor, Jawa Barat 16128, Indonesia; (D.I.); (D.S.)
- Primate Research Center, IPB University, Bogor, Jawa Barat 16128, Indonesia;
| | - Michael H. Norris
- Spatial Epidemiology & Ecology Research Laboratory, Department of Geography, University of Florida, Gainesville, FL 32611, USA;
- Emerging Pathogens Institute, University of Florida, Gainesville, FL 32610, USA; (T.J.); (A.T.)
| | - Treenate Jiranantasak
- Emerging Pathogens Institute, University of Florida, Gainesville, FL 32610, USA; (T.J.); (A.T.)
- Department of Infectious Diseases and Immunology, University of Florida, Gainesville, FL 32610, USA
| | - Apichai Tuanyok
- Emerging Pathogens Institute, University of Florida, Gainesville, FL 32610, USA; (T.J.); (A.T.)
- Department of Infectious Diseases and Immunology, University of Florida, Gainesville, FL 32610, USA
| | - Aris Tri Wahyudi
- Department of Biology, Faculty of Mathematics and Natural Sciences, IPB University, Bogor, Jawa Barat 16680, Indonesia;
| | - Dondin Sajuthi
- Primatology Study Program, Graduate School of IPB University, Bogor, Jawa Barat 16128, Indonesia; (D.I.); (D.S.)
- Primate Research Center, IPB University, Bogor, Jawa Barat 16128, Indonesia;
- Department of Clinics, Reproduction, and Pathology, Faculty of Veterinary Medicine, IPB University, Bogor, Jawa Barat 16680, Indonesia
| | - Joko Pamungkas
- Primatology Study Program, Graduate School of IPB University, Bogor, Jawa Barat 16128, Indonesia; (D.I.); (D.S.)
- Primate Research Center, IPB University, Bogor, Jawa Barat 16128, Indonesia;
- Department of Animal Infectious Diseases and Veterinary Public Health, Faculty of Veterinary Medicine, IPB University, Bogor, Jawa Barat 16680, Indonesia
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Saikh KU, Ranji CM, Ulrich RG, Corea E, De Silva AD, Natesan M. An increase in p62/NBR1 levels in melioidosis patients of Sri Lanka exhibit a characteristic of potential host biomarker. J Med Microbiol 2020; 69:1240-1248. [PMID: 32815800 PMCID: PMC7660894 DOI: 10.1099/jmm.0.001242] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/02/2020] [Accepted: 07/23/2020] [Indexed: 12/18/2022] Open
Abstract
Introduction. Melioidosis, caused by Burkholderia pseudomallei, in endemic areas, poses a challenge for treating the diseased populations without accurate diagnosis, and the disease-specific biomarkers linked with the infection have yet to be reported. Due to the invasive nature of the causative agent, Burkholderia pseudomallei, host innate effector mechanisms, including autophagy are known to be activated, resulting in differential expression of cellular proteins and immune markers. Identification of a disease-specific biomarker associated with B. pseudomallei infection will be helpful to facilitate rapid confirmation of melioidosis, which would enable early treatment and therapeutic success.Aim. We aimed to assess the levels of a host autophagy component, p62/NBR1, which function as a cargo-receptor in the process of autophagy activation leading to the degradation of ubiquitin-coated intracellular bacteria in which p62/NBR1 itself is degraded in the clearance of the pathogen. We further probed the extent of intracellular p62/NBR1 degradation and assessed its potential as a melioidosis biomarker.Methodology. We analysed peripheral blood mononuclear cell (PBMC) lysates using an ELISA-based assay for detecting cytosolic autophagy-related proteins p62/NBR1. We measured p62/NBR1 levels in diseased (confirmed B. pseudomallei infection) and non -diseased populations and utilized receiver operating characteristic (ROC) curve and max Youden index analysis for evaluating potential disease biomarker characteristics.Results. Our results revealed a three to fivefold increase in p62/NBR1 levels confirmed melioidosis cases compared to uninfected healthy donors. Comparable to p62/NBR1, levels of cytosolic LC3-I levels also increased, whereas the levels of degraded membrane bound form LC3-II was low, suggesting autophagy deficiency. Proinflammatory serum cytokine response, particularly IL-6, was consistently higher alongside B. pseudomallei infection in comparison to healthy controls.Conclusions. ROC curve and max Youden index analysis suggest that increased p62/NBR1 levels in diseased populations display characteristics of a potential disease biomarker in melioidosis and illustrates that an elevated p62/NBR1 level, in conjunction with B. pseudomallei infection associated with autophagy deficiency.
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Affiliation(s)
- Kamal U. Saikh
- Department of Immunology, United States Army Medical Research Institute of Infectious Diseases, Frederick, MD, USA
| | - Cyra M. Ranji
- Department of Immunology, United States Army Medical Research Institute of Infectious Diseases, Frederick, MD, USA
| | - Robert G. Ulrich
- Department of Immunology, United States Army Medical Research Institute of Infectious Diseases, Frederick, MD, USA
| | - Enoka Corea
- Department of Microbiology, University of Colombo, Colombo, Sri Lanka
| | - Aruna Dharshan De Silva
- Division of Vaccine Discovery, La Jolla Institute of Allergy and Immunology, La Jolla, CA, USA
- Department of Paraclinical Sciences, Faculty of Medicine, Kotelawala Defence University, Ratmalana, Sri Lanka
| | - Mohan Natesan
- Department of Immunology, United States Army Medical Research Institute of Infectious Diseases, Frederick, MD, USA
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Burkholderia pseudomallei pathogenesis and survival in different niches. Biochem Soc Trans 2020; 48:569-579. [PMID: 32167134 DOI: 10.1042/bst20190836] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/28/2019] [Revised: 02/24/2020] [Accepted: 02/25/2020] [Indexed: 01/16/2023]
Abstract
Burkholderia pseudomallei (Bp) is the causative agent of melioidosis, a disease of the tropics with high clinical mortality rates. To date, no vaccines are approved for melioidosis and current treatment relies on antibiotics. Conversely, common misdiagnosis and high pathogenicity of Bp hamper efforts to fight melioidosis. This bacterium can be isolated from a wide range of niches such as waterlogged fields, stagnant water bodies, salt water bodies and from human and animal clinical specimens. Although extensive studies have been undertaken to elucidate pathogenesis mechanisms of Bp, little is known about how a harmless soil bacterium adapts to different environmental conditions, in particular, the shift to a human host to become a highly virulent pathogen. The bacterium has a large genome encoding an armory of factors that assist the pathogen in surviving under stressful conditions and assuming its role as a deadly intracellular pathogen. This review presents an overview of what is currently known about how the pathogen adapts to different environments. With in-depth understanding of Bp adaptation and survival, more effective therapies for melioidosis can be developed by targeting related genes or proteins that play a major role in the bacteria's survival.
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25
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Chen YL, Hsu DW, Hsueh PT, Chen JA, Shih PJ, Lee S, Lin HH, Chen YS. Distinct Pathogenic Patterns of Burkholderia pseudomallei Isolates Selected from Caenorhabditis elegans and Dictyostelium discoideum Models. Am J Trop Med Hyg 2020; 101:736-745. [PMID: 31392941 DOI: 10.4269/ajtmh.19-0052] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/23/2023] Open
Abstract
Burkholderia pseudomallei is a selective agent that causes septic melioidosis and exhibits a broad range of lethal doses in animals. Host cellular virulence and phagocytic resistance are pathologic keys of B. pseudomallei. We first proposed Caenorhabditis elegans as the host cellular virulence model to mimic bacterial virulence against mammals and second established the resistance of B. pseudomallei to predation by Dictyostelium discoideum as the phagocytosis model. The saprophytic sepsis-causing Burkholderia sp. (B. pseudomallei, Burkholderia thailandensis, Burkholderia cenocepacia, and Burkholderia multivorans) exhibited different virulence patterns in both simple models, but B. pseudomallei was the most toxic. Using both models, attenuated isolates of B. pseudomallei were selected from a transposon-mutant library and a panel of environmental isolates and reconfirmed by in vitro mouse peritoneal exudate cell association and invasion assays. The distinct pathological patterns of melioidosis were inducted by different selected B. pseudomallei isolates. Fatal melioidosis was induced by the isolates with high virulence in both simple models within 4-5 day, whereas the low-virulence isolates resulted in prolonged survival greater than 30 day. Infection with the isolates having high resistance to D. discoideum predation but a low C. elegans killing effect led to 83% of mice with neurologic melioidosis. By contrast, infection with the isolates having low resistance to D. discoideum predation but high C. elegans killing effect led to 20% cases with inflammation in the salivary glands. Our results indicated that individual B. pseudomallei isolates selected from simple biological models contribute differently to disease progression and/or tissue tropism.
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Affiliation(s)
- Ya-Lei Chen
- Department of Biotechnology, National Kaohsiung Normal University, Kaohsiung, Taiwan
| | - Duen-Wei Hsu
- Department of Biotechnology, National Kaohsiung Normal University, Kaohsiung, Taiwan
| | - Pei-Tan Hsueh
- Department of Internal Medicine, Kaohsiung Veterans General Hospital, Kaohsiung, Taiwan
| | - Jou-An Chen
- Department of Biotechnology, National Kaohsiung Normal University, Kaohsiung, Taiwan
| | - Pei-Jyun Shih
- Department of Biotechnology, National Kaohsiung Normal University, Kaohsiung, Taiwan
| | - Susan Lee
- Department of Internal Medicine, Kaohsiung Veterans General Hospital, Kaohsiung, Taiwan
| | - Hsi-Hsun Lin
- School of Medicine, Institute of Public Health, National Yang-Ming University, Taipei, Taiwan.,Medical Research Department, General Clinical Research Center, Taipei Veterans General Hospital, Taipei, Taiwan
| | - Yao-Shen Chen
- Department of Internal Medicine, Kaohsiung Veterans General Hospital, Kaohsiung, Taiwan.,Department of Internal Medicine, National Yang-Ming University, Taipei, Taiwan
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26
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Pearson T, Sahl JW, Hepp CM, Handady K, Hornstra H, Vazquez AJ, Settles E, Mayo M, Kaestli M, Williamson CHD, Price EP, Sarovich DS, Cook JM, Wolken SR, Bowen RA, Tuanyok A, Foster JT, Drees KP, Kidd TJ, Bell SC, Currie BJ, Keim P. Pathogen to commensal? Longitudinal within-host population dynamics, evolution, and adaptation during a chronic >16-year Burkholderia pseudomallei infection. PLoS Pathog 2020; 16:e1008298. [PMID: 32134991 PMCID: PMC7077878 DOI: 10.1371/journal.ppat.1008298] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/17/2019] [Revised: 03/17/2020] [Accepted: 01/02/2020] [Indexed: 12/14/2022] Open
Abstract
Although acute melioidosis is the most common outcome of Burkholderia pseudomallei infection, we have documented a case, P314, where disease severity lessened with time, and the pathogen evolved towards a commensal relationship with the host. In the current study, we used whole-genome sequencing to monitor this long-term symbiotic relationship to better understand B. pseudomallei persistence in P314's sputum despite intensive initial therapeutic regimens. We collected and sequenced 118 B. pseudomallei isolates from P314's airways over a >16-year period, and also sampled the patient's home environment, recovering six closely related B. pseudomallei isolates from the household water system. Using comparative genomics, we identified 126 SNPs in the core genome of the 124 isolates or 162 SNPs/indels when the accessory genome was included. The core SNPs were used to construct a phylogenetic tree, which demonstrated a close relationship between environmental and clinical isolates and detailed within-host evolutionary patterns. The phylogeny had little homoplasy, consistent with a strictly clonal mode of genetic inheritance. Repeated sampling revealed evidence of genetic diversification, but frequent extinctions left only one successful lineage through the first four years and two lineages after that. Overall, the evolution of this population is nonadaptive and best explained by genetic drift. However, some genetic and phenotypic changes are consistent with in situ adaptation. Using a mouse model, P314 isolates caused greatly reduced morbidity and mortality compared to the environmental isolates. Additionally, potentially adaptive phenotypes emerged and included differences in the O-antigen, capsular polysaccharide, motility, and colony morphology. The >13-year co-existence of two long-lived lineages presents interesting hypotheses that can be tested in future studies to provide additional insights into selective pressures, niche differentiation, and microbial adaptation. This unusual melioidosis case presents a rare example of the evolutionary progression towards commensalism by a highly virulent pathogen within a single human host.
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Affiliation(s)
- Talima Pearson
- Pathogen & Microbiome Institute, Northern Arizona University, Flagstaff, Arizona, United States of America
| | - Jason W. Sahl
- Pathogen & Microbiome Institute, Northern Arizona University, Flagstaff, Arizona, United States of America
| | - Crystal M. Hepp
- Pathogen & Microbiome Institute, Northern Arizona University, Flagstaff, Arizona, United States of America
- School of Informatics, Computing, and Cyber Systems, Northern Arizona University, Flagstaff, Arizona, United States of America
| | - Karthik Handady
- Pathogen & Microbiome Institute, Northern Arizona University, Flagstaff, Arizona, United States of America
| | - Heidie Hornstra
- Pathogen & Microbiome Institute, Northern Arizona University, Flagstaff, Arizona, United States of America
| | - Adam J. Vazquez
- Pathogen & Microbiome Institute, Northern Arizona University, Flagstaff, Arizona, United States of America
| | - Erik Settles
- Pathogen & Microbiome Institute, Northern Arizona University, Flagstaff, Arizona, United States of America
| | - Mark Mayo
- Global and Tropical Health Division, Menzies School of Health Research, Darwin, Northern Territory, Australia
| | - Mirjam Kaestli
- Global and Tropical Health Division, Menzies School of Health Research, Darwin, Northern Territory, Australia
| | - Charles H. D. Williamson
- Pathogen & Microbiome Institute, Northern Arizona University, Flagstaff, Arizona, United States of America
| | - Erin P. Price
- Pathogen & Microbiome Institute, Northern Arizona University, Flagstaff, Arizona, United States of America
| | - Derek S. Sarovich
- Pathogen & Microbiome Institute, Northern Arizona University, Flagstaff, Arizona, United States of America
| | - James M. Cook
- Pathogen & Microbiome Institute, Northern Arizona University, Flagstaff, Arizona, United States of America
| | - Spenser R. Wolken
- Pathogen & Microbiome Institute, Northern Arizona University, Flagstaff, Arizona, United States of America
| | - Richard A. Bowen
- Department of Biomedical Sciences, Colorado State University, Colorado, United States of America
| | - Apichai Tuanyok
- Pathogen & Microbiome Institute, Northern Arizona University, Flagstaff, Arizona, United States of America
| | - Jeffrey T. Foster
- Pathogen & Microbiome Institute, Northern Arizona University, Flagstaff, Arizona, United States of America
| | - Kevin P. Drees
- Pathogen & Microbiome Institute, Northern Arizona University, Flagstaff, Arizona, United States of America
| | - Timothy J. Kidd
- School of Chemistry and Molecular Biosciences, University of Queensland, Brisbane, Queensland, Australia
| | - Scott C. Bell
- Department of Thoracic Medicine, The Prince Charles Hospital, Chermside, and QIMR Berghofer Medical Research Institute, Queensland, Australia
| | - Bart J. Currie
- Global and Tropical Health Division, Menzies School of Health Research, Darwin, Northern Territory, Australia
- Infectious Diseases Department and Northern Territory Medical Program, Royal Darwin Hospital, Darwin, Northern Territory, Australia
| | - Paul Keim
- Pathogen & Microbiome Institute, Northern Arizona University, Flagstaff, Arizona, United States of America
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Ferro P, Vaz-Moreira I, Manaia CM. Betaproteobacteria are predominant in drinking water: are there reasons for concern? Crit Rev Microbiol 2019; 45:649-667. [PMID: 31686572 DOI: 10.1080/1040841x.2019.1680602] [Citation(s) in RCA: 13] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/01/2023]
Abstract
Betaproteobacteria include some of the most abundant and ubiquitous bacterial genera that can be found in drinking water, including mineral water. The combination of physiology and ecology traits place some Betaproteobacteria in the list of potential, yet sometimes neglected, opportunistic pathogens that can be transmitted by water or aqueous solutions. Indeed, some drinking water Betaproteobacteria with intrinsic and sometimes acquired antibiotic resistance, harbouring virulence factors and often found in biofilm structures, can persist after water disinfection and reach the consumer. This literature review summarises and discusses the current knowledge about the occurrence and implications of Betaproteobacteria in drinking water. Although the sparse knowledge on the ecology and physiology of Betaproteobacteria thriving in tap or bottled natural mineral/spring drinking water (DW) is an evidence of this review, it is demonstrated that DW holds a high diversity of Betaproteobacteria, whose presence may not be innocuous. Frequently belonging to genera also found in humans, DW Betaproteobacteria are ubiquitous in different habitats, have the potential to resist antibiotics either due to intrinsic or acquired mechanisms, and hold different virulence factors. The combination of these factors places DW Betaproteobacteria in the list of candidates of emerging opportunistic pathogens. Improved bacterial identification of clinical isolates associated with opportunistic infections and additional genomic and physiological studies may contribute to elucidate the potential impact of these bacteria.
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Affiliation(s)
- Pompeyo Ferro
- Universidade Católica Portuguesa, CBQF - Centro de Biotecnologia e Química Fina - Laboratório Associado, Escola Superior de Biotecnologia, Porto, Portugal
| | - Ivone Vaz-Moreira
- Universidade Católica Portuguesa, CBQF - Centro de Biotecnologia e Química Fina - Laboratório Associado, Escola Superior de Biotecnologia, Porto, Portugal
| | - Célia M Manaia
- Universidade Católica Portuguesa, CBQF - Centro de Biotecnologia e Química Fina - Laboratório Associado, Escola Superior de Biotecnologia, Porto, Portugal
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28
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Immunogenicity and protective efficacy of Burkholderia pseudomallei BLF1-N and BLF1-C terminal domains against BLF1 toxin. Int Immunopharmacol 2019; 77:105917. [PMID: 31675617 DOI: 10.1016/j.intimp.2019.105917] [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: 05/24/2019] [Revised: 08/24/2019] [Accepted: 09/13/2019] [Indexed: 11/24/2022]
Abstract
Burkholderia lethal factor 1 (BLF1), a glutamine deamidase, is a key virulence factor that plays significant role in B. pseudomallei pathogenesis. To elucidate the BLF1 immunological responses, two truncated BLF1 structural units, BLF1-C (90-211 amino acids) with structural similarity to T. maritima Chemoreceptor glutamine deamidase (CheD) protein, and BLF1-N (1-89 amino acids) disparate to CheD were identified from the 23 kDa BLF1 protein. Both the components were devoid of toxicity in mice and elicited an antibody titer of 1:16,000 that reacted with the respective truncated proteins and BLF1. A549 cell lines supplemented with anti BLF1-N and BLF1-C antibodies exhibited 73.47% and 83.24% survival when treated with BLF1 toxin. Passive i.p. transfer with antibodies elicited by BLF1-C that contained LSGC active site resulted in 80% protection while anti BLF1-N (devoid of LSGC) antibodies provided 51.4% protection, establishing the role of BLF1-N terminal also in deamidase action. The truncated proteins also elicited cell mediated immune responses through proliferation of CD4+ T cells, IFN-γ and IL-4 cytokines but with bias towards Th2 subsets. BLF1-C and BLF1-N immunization resulted in 80% and 60% active protection when challenged with BLF1 toxin while the sham immunized mice exhibited severe histopathological changes like necrosis in liver, lung, spleen and kidney similar to that observed in melioidosis and were killed within 7 days post challenge. The higher level of active and passive protection by BLF1-C protein could be attributed to the comparatively higher level of immune responses and inclusion of LSGC residues.
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29
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Khojandi N, Haselkorn TS, Eschbach MN, Naser RA, DiSalvo S. Intracellular Burkholderia Symbionts induce extracellular secondary infections; driving diverse host outcomes that vary by genotype and environment. THE ISME JOURNAL 2019; 13:2068-2081. [PMID: 31019270 PMCID: PMC6776111 DOI: 10.1038/s41396-019-0419-7] [Citation(s) in RCA: 13] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 10/19/2018] [Revised: 01/06/2019] [Accepted: 04/10/2019] [Indexed: 02/07/2023]
Abstract
Symbiotic associations impact and are impacted by their surrounding ecosystem. The association between Burkholderia bacteria and the soil amoeba Dictyostelium discoideum is a tractable model to unravel the biology underlying symbiont-endowed phenotypes and their impacts. Several Burkholderia species stably associate with D. discoideum and typically reduce host fitness in food-rich environments while increasing fitness in food-scarce environments. Burkholderia symbionts are themselves inedible to their hosts but induce co-infections with secondary bacteria that can serve as a food source. Thus, Burkholderia hosts are "farmers" that carry food bacteria to new environments, providing a benefit when food is scarce. We examined the ability of specific Burkholderia genotypes to induce secondary co-infections and assessed host fitness under a range of co-infection conditions and environmental contexts. Although all Burkholderia symbionts intracellularly infected Dictyostelium, we found that co-infections are predominantly extracellular, suggesting that farming benefits are derived from extracellular infection of host structures. Furthermore, levels of secondary infection are linked to conditional host fitness; B. agricolaris infected hosts have the highest level of co-infection and have the highest fitness in food-scarce environments. This study illuminates the phenomenon of co-infection induction across Dictyostelium associated Burkholderia species and exemplifies the contextual complexity of these associations.
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Affiliation(s)
- Niloufar Khojandi
- Department of Biological Sciences, Southern Illinois University Edwardsville, Edwardsville, IL, 62026, USA
- Department of Molecular Microbiology and Immunology, St. Louis University, St. Louis, MO, 63104, USA
| | - Tamara S Haselkorn
- Department of Biology, University of Central Arkansas, 201 Donaghey Avenue, Conway, AR, 72035, USA
| | - Madison N Eschbach
- Department of Biological Sciences, Southern Illinois University Edwardsville, Edwardsville, IL, 62026, USA
| | - Rana A Naser
- Department of Biological Sciences, Southern Illinois University Edwardsville, Edwardsville, IL, 62026, USA
| | - Susanne DiSalvo
- Department of Biological Sciences, Southern Illinois University Edwardsville, Edwardsville, IL, 62026, USA.
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Kovacs-Simon A, Hemsley CM, Scott AE, Prior JL, Titball RW. Burkholderia thailandensis strain E555 is a surrogate for the investigation of Burkholderia pseudomallei replication and survival in macrophages. BMC Microbiol 2019; 19:97. [PMID: 31092204 PMCID: PMC6521459 DOI: 10.1186/s12866-019-1469-8] [Citation(s) in RCA: 16] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/06/2018] [Accepted: 04/30/2019] [Indexed: 02/02/2023] Open
Abstract
Background Burkholderia pseudomallei is a human pathogen causing severe infections in tropical and subtropical regions and is classified as a bio-threat agent. B. thailandensis strain E264 has been proposed as less pathogenic surrogate for understanding the interactions of B. pseudomallei with host cells. Results We show that, unlike B. thailandensis strain E264, the pattern of growth of B. thailandensis strain E555 in macrophages is similar to that of B. pseudomallei. We have genome sequenced B. thailandensis strain E555 and using the annotated sequence identified genes and proteins up-regulated during infection. Changes in gene expression identified more of the known B. pseudomallei virulence factors than changes in protein levels and used together we identified 16% of the currently known B. pseudomallei virulence factors. These findings demonstrate the utility of B. thailandensis strain E555 to study virulence of B. pseudomallei. Conclusions A weakness of studies using B. thailandensis as a surrogate for B. pseudomallei is that the strains used replicate at a slower rate in infected cells. We show that the pattern of growth of B. thailandensis strain E555 in macrophages closely mirrors that of B. pseudomallei. Using this infection model we have shown that virulence factors of B. pseudomallei can be identified as genes or proteins whose expression is elevated on the infection of macrophages. This finding confirms the utility of B. thailandensis strain E555 as a surrogate for B. pseudomallei and this strain should be used for future studies on virulence mechanisms. Electronic supplementary material The online version of this article (10.1186/s12866-019-1469-8) contains supplementary material, which is available to authorized users.
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Affiliation(s)
- A Kovacs-Simon
- College of Life and Environmental Sciences, University of Exeter, Geoffrey Pope Building, Stocker Road, Exeter, EX4 4QD, UK.
| | - C M Hemsley
- College of Life and Environmental Sciences, University of Exeter, Geoffrey Pope Building, Stocker Road, Exeter, EX4 4QD, UK
| | - A E Scott
- CBR Division, Defence Science and Technology Laboratory, Porton Down, Salisbury, SP4 0JQ, UK
| | - J L Prior
- College of Life and Environmental Sciences, University of Exeter, Geoffrey Pope Building, Stocker Road, Exeter, EX4 4QD, UK.,CBR Division, Defence Science and Technology Laboratory, Porton Down, Salisbury, SP4 0JQ, UK
| | - R W Titball
- College of Life and Environmental Sciences, University of Exeter, Geoffrey Pope Building, Stocker Road, Exeter, EX4 4QD, UK
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Lafontaine ER, Chen Z, Huertas-Diaz MC, Dyke JS, Jelesijevic TP, Michel F, Hogan RJ, He B. The autotransporter protein BatA is a protective antigen against lethal aerosol infection with Burkholderia mallei and Burkholderia pseudomallei. Vaccine X 2019; 1:100002. [PMID: 33826684 PMCID: PMC6668238 DOI: 10.1016/j.jvacx.2018.100002] [Citation(s) in RCA: 12] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/09/2018] [Revised: 08/06/2018] [Accepted: 12/07/2018] [Indexed: 02/06/2023] Open
Abstract
BACKGROUND Burkholderia mallei and Burkholderia pseudomallei are the causative agents of glanders and melioidosis, respectively. There is no vaccine to protect against these highly-pathogenic and intrinsically antibiotic-resistant bacteria, and there is concern regarding their use as biological warfare agents. For these reasons, B. mallei and B. pseudomallei are classified as Tier 1 organisms by the U.S. Federal Select Agent Program and the availability of effective countermeasures represents a critical unmet need. METHODS Vaccines (subunit and vectored) containing the surface-exposed passenger domain of the conserved Burkholderia autotransporter protein BatA were administered to BALB/c mice and the vaccinated animals were challenged with lethal doses of wild-type B. mallei and B. pseudomallei strains via the aerosol route. Mice were monitored for signs of illness for a period of up to 40 days post-challenge and tissues from surviving animals were analyzed for bacterial burden at study end-points. RESULTS A single dose of recombinant Parainfluenza Virus 5 (PIV5) expressing BatA provided 74% and 60% survival in mice infected with B. mallei and B. pseudomallei, respectively. Vaccination with PIV5-BatA also resulted in complete bacterial clearance from the lungs and spleen of 78% and 44% of animals surviving lethal challenge with B. pseudomallei, respectively. In contrast, all control animals vaccinated with a PIV5 construct expressing an irrelevant antigen and infected with B. pseudomallei were colonized in those tissues. CONCLUSION Our study indicates that the autotransporter BatA is a valuable target for developing countermeasures against B. mallei and B. pseudomallei and demonstrates the utility of the PIV5 viral vaccine delivery platform to elicit cross-protective immunity against the organisms.
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Affiliation(s)
- Eric R. Lafontaine
- Department of Infectious Diseases, University of Georgia College of Veterinary Medicine, Athens, GA 30602, USA
| | - Zhenhai Chen
- Department of Infectious Diseases, University of Georgia College of Veterinary Medicine, Athens, GA 30602, USA
| | - Maria Cristina Huertas-Diaz
- Department of Infectious Diseases, University of Georgia College of Veterinary Medicine, Athens, GA 30602, USA
| | - Jeremy S. Dyke
- Department of Infectious Diseases, University of Georgia College of Veterinary Medicine, Athens, GA 30602, USA
| | - Tomislav P. Jelesijevic
- Department of Infectious Diseases, University of Georgia College of Veterinary Medicine, Athens, GA 30602, USA
| | - Frank Michel
- Department of Veterinary Biosciences and Diagnostic Imaging, University of Georgia College of Veterinary Medicine, Athens, GA 30602, USA
| | - Robert J. Hogan
- Department of Infectious Diseases, University of Georgia College of Veterinary Medicine, Athens, GA 30602, USA
- Department of Veterinary Biosciences and Diagnostic Imaging, University of Georgia College of Veterinary Medicine, Athens, GA 30602, USA
| | - Biao He
- Department of Infectious Diseases, University of Georgia College of Veterinary Medicine, Athens, GA 30602, USA
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32
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Morici L, Torres AG, Titball RW. Novel multi-component vaccine approaches for Burkholderia pseudomallei. Clin Exp Immunol 2019; 196:178-188. [PMID: 30963550 DOI: 10.1111/cei.13286] [Citation(s) in RCA: 17] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 12/20/2018] [Indexed: 12/16/2022] Open
Abstract
Burkholderia pseudomallei is the causative agent of melioidosis. Historically believed to be a relatively rare human disease in tropical countries, a recent study estimated that, worldwide, there are approximately 165 000 human melioidosis cases per year, more than half of whom die. The bacterium is inherently resistant to many antibiotics and treatment of the disease is often protracted and ineffective. There is no licensed vaccine against melioidosis, but a vaccine is predicted to be of value if used in high-risk populations. There has been progress over the last decade in the pursuit of an effective vaccine against melioidosis. Animal models of disease including mouse and non-human primates have been developed, and these models show that antibody responses play a key role in protection against melioidosis. Surprisingly, although B. pseudomallei is an intracellular pathogen there is limited evidence that CD8+ T cells play a role in protection. It is evident that a multi-component vaccine, incorporating one or more protective antigens, will probably be essential for protection because of the pathogen's sophisticated virulence mechanisms as well as strain heterogeneity. Multi-component vaccines in development include glycoconjugates, multivalent subunit preparations, outer membrane vesicles and other nano/microparticle platforms and live-attenuated or inactivated bacteria. A consistent finding with vaccine candidates tested in mice is the ability to induce sterilizing immunity at low challenge doses and extended time to death at higher challenge doses. Further research to identify ways of eliciting more potent immune responses might provide a path for licensing an effective vaccine.
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Affiliation(s)
- L Morici
- Department of Microbiology and Immunology, Tulane University School of Medicine, New Orleans, LA, USA
| | - A G Torres
- Department of Microbiology and Immunology, University of Texas Medical Branch, Galveston, Texas, USA
| | - R W Titball
- College of Life and Environmental Science, University of Exeter, Exeter, UK
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Limmathurotsakul D, Daily F, Bory S, Khim G, Wiersinga WJ, Torres AG, Dance DAB, Currie BJ. Melioidosis: The hazards of incomplete peer-review. PLoS Negl Trop Dis 2019; 13:e0007123. [PMID: 30870410 PMCID: PMC6417648 DOI: 10.1371/journal.pntd.0007123] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/17/2018] [Accepted: 01/03/2019] [Indexed: 12/30/2022] Open
Affiliation(s)
- Direk Limmathurotsakul
- Mahidol Oxford Tropical Medicine Research Unit and Department of Tropical Hygiene, Faculty of Tropical Medicine, Mahidol University, Bangkok, Thailand.,Centre for Tropical Medicine and Global Health, Nuffield Department of Medicine, University of Oxford, Oxford, United Kingdom
| | - Frances Daily
- Diagnostic Microbiology Development Program, Phnom Penh, Cambodia
| | - Sotharith Bory
- Infectious Diseases Unit, Calmette Hospital, Phnom Penh, Cambodia
| | - Gaetan Khim
- Diagnostic Microbiology Development Program, Phnom Penh, Cambodia
| | - W Joost Wiersinga
- Department of Medicine, Division of Infectious Diseases, Academic Medical Center, Amsterdam, The Netherlands.,Centre for Experimental and Molecular Medicine, Academic Medical Center, Amsterdam, The Netherlands
| | - Alfredo G Torres
- The Herman Barnett Distinguished Professor in Microbiology and Immunology, Assistant Dean of Faculty Affairs and Professional Development, OFAPD, University of Texas Medical Branch, Galveston, Texas, United States of America
| | - David A B Dance
- Centre for Tropical Medicine and Global Health, Nuffield Department of Medicine, University of Oxford, Oxford, United Kingdom.,Lao-Oxford-Mahosot Hospital Wellcome Trust Research Unit, Vientiane, Lao People's Democratic Republic
| | - Bart J Currie
- Menzies School of Health Research, Charles Darwin University and Infectious Diseases Department, Royal Darwin Hospital and Northern Territory Medical Program, Darwin NT, Australia
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Lennings J, West TE, Schwarz S. The Burkholderia Type VI Secretion System 5: Composition, Regulation and Role in Virulence. Front Microbiol 2019; 9:3339. [PMID: 30687298 PMCID: PMC6335564 DOI: 10.3389/fmicb.2018.03339] [Citation(s) in RCA: 34] [Impact Index Per Article: 6.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/14/2018] [Accepted: 12/24/2018] [Indexed: 12/19/2022] Open
Abstract
The soil saprophyte and Tier I select agent Burkholderia pseudomallei can cause rapidly fatal infections in humans and animals. The capability of switching to an intracellular life cycle during infection appears to be a decisive trait of B. pseudomallei for causing disease. B. pseudomallei harbors multiple type VI secretion systems (T6SSs) orthologs of which are present in the surrogate organism Burkholderia thailandensis. Upon host cell entry and vacuolar escape into the cytoplasm, B. pseudomallei and B. thailandensis manipulate host cells by utilizing the T6SS-5 (also termed T6SS1) to form multinucleated giant cells for intercellular spread. Disruption of the T6SS-5 in B. thailandensis causes a drastic attenuation of virulence in wildtype but not in mice lacking the central innate immune adapter protein MyD88. This result suggests that the T6SS-5 is deployed by the bacteria to overcome innate immune responses. However, important questions in this field remain unsolved including the mechanism underlying T6SS-5 activity and its physiological role during infection. In this review, we summarize the current knowledge on the components and regulation of the T6SS-5 as well as its role in virulence in mammalian hosts.
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Affiliation(s)
- Jan Lennings
- Interfaculty Institute of Microbiology and Infection Medicine, University of Tübingen, Tübingen, Germany
| | - T Eoin West
- Division of Pulmonary, Critical Care and Sleep Medicine, Department of Medicine, University of Washington, Seattle, WA, United States
| | - Sandra Schwarz
- Interfaculty Institute of Microbiology and Infection Medicine, University of Tübingen, Tübingen, Germany
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35
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Laws TR, Taylor AW, Russell P, Williamson D. The treatment of melioidosis: is there a role for repurposed drugs? A proposal and review. Expert Rev Anti Infect Ther 2019; 17:957-967. [PMID: 30626237 DOI: 10.1080/14787210.2018.1496330] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/07/2023]
Abstract
Introduction: Melioidosis is a significant health problem within endemic areas such as Southeast Asia and Northern Australia. The varied presentation of melioidosis and the intrinsic antibiotic resistance of Burkholderia pseudomallei, the causative organism, make melioidosis a difficult infection to manage. Often prolonged courses of antibiotic treatments are required with no guarantee of clinical success.Areas covered: B. pseudomallei is able to enter phagocytic cells, affect immune function, and replicate, via manipulation of the caspase system. An examination of this mechanism, and a look at other factors in the pathogenesis of melioidosis, shows that there are multiple potential points of therapeutic intervention, some of which may be complementary. These include the directed use of antimicrobial compounds, blocking virulence mechanisms, balancing or modulating cytokine responses, and ameliorating sepsis.Expert commentary: There may be therapeutic options derived from drugs in clinical use for unrelated conditions that may have benefit in melioidosis. Key compounds of interest primarily affect the disequilibrium of the cytokine response, and further preclinical work is needed to explore the utility of this approach and encourage the clinical research needed to bring these into beneficial use.
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Affiliation(s)
- Thomas R Laws
- CBR Division, DSTL Porton Down, Salisbury, Wiltshire, UK
| | - Adam W Taylor
- CBR Division, DSTL Porton Down, Salisbury, Wiltshire, UK
| | - Paul Russell
- CBR Division, DSTL Porton Down, Salisbury, Wiltshire, UK
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Inflammasomes, Autophagy, and Cell Death: The Trinity of Innate Host Defense against Intracellular Bacteria. Mediators Inflamm 2019; 2019:2471215. [PMID: 30728749 PMCID: PMC6341260 DOI: 10.1155/2019/2471215] [Citation(s) in RCA: 71] [Impact Index Per Article: 14.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/16/2018] [Accepted: 12/19/2018] [Indexed: 01/17/2023] Open
Abstract
Inflammasome activation is an innate host defense mechanism initiated upon sensing pathogens or danger in the cytosol. Both autophagy and cell death are cell autonomous processes important in development, as well as in host defense against intracellular bacteria. Inflammasome, autophagy, and cell death pathways can be activated by pathogens, pathogen-associated molecular patterns (PAMPs), cell stress, and host-derived damage-associated molecular patterns (DAMPs). Phagocytosis and toll-like receptor (TLR) signaling induce reactive oxygen species (ROS), type I IFN, NFκB activation of proinflammatory cytokines, and the mitogen-activated protein kinase cascade. ROS and IFNγ are also prominent inducers of autophagy. Pathogens, PAMPs, and DAMPs activate TLRs and intracellular inflammasomes, inducing apoptotic and inflammatory caspases in a context-dependent manner to promote various forms of cell death to eliminate pathogens. Common downstream signaling molecules of inflammasomes, autophagy, and cell death pathways interact to initiate appropriate measures against pathogens and determine host survival as well as pathological consequences of infection. The integration of inflammasome activation, autophagy, and cell death is central to pathogen clearance. Various pathogens produce virulence factors to control inflammasomes, subvert autophagy, and modulate host cell death in order to evade host defense. This review highlights the interaction of inflammasomes, autophagy, and host cell death pathways in counteracting Burkholderia pseudomallei, the causative agent of melioidosis. Contrasting evasion strategies used by B. pseudomallei, Mycobacterium tuberculosis, and Legionella pneumophila to avoid and dampen these innate immune responses will be discussed.
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37
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Hogan RJ, Lafontaine ER. Antibodies Are Major Drivers of Protection against Lethal Aerosol Infection with Highly Pathogenic Burkholderia spp. mSphere 2019; 4:e00674-18. [PMID: 30602525 PMCID: PMC6315082 DOI: 10.1128/msphere.00674-18] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/06/2023] Open
Abstract
Burkholderia pseudomallei and Burkholderia mallei are the causative agents of melioidosis and glanders, respectively. There is no vaccine to protect against these highly pathogenic bacteria, and there is concern regarding their emergence as global public health (B. pseudomallei) and biosecurity (B. mallei) threats. In this issue of mSphere, an article by Khakhum and colleagues (N. Khakhum, P. Bharaj, J. N. Myers, D. Tapia, et al., mSphere 4:e00570-18, 2019, https://doi.org/10.1128/mSphere.00570-18) describes a novel vaccination platform with excellent potential for cross-protection against both Burkholderia species. The report also highlights the importance of antibodies in immunity against these facultative intracellular organisms.
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Affiliation(s)
- Robert J Hogan
- Department of Infectious Diseases, College of Veterinary Medicine, University of Georgia, Athens, Georgia, USA
- Department of Veterinary Biosciences and Diagnostic Imaging, College of Veterinary Medicine, University of Georgia, Athens, Georgia, USA
| | - Eric R Lafontaine
- Department of Infectious Diseases, College of Veterinary Medicine, University of Georgia, Athens, Georgia, USA
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38
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Burkholderia pseudomallei-loaded cells act as a Trojan horse to invade the brain during endotoxemia. Sci Rep 2018; 8:13632. [PMID: 30206252 PMCID: PMC6134107 DOI: 10.1038/s41598-018-31778-8] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/26/2018] [Accepted: 08/22/2018] [Indexed: 01/22/2023] Open
Abstract
Neurologic melioidosis occurs in both human and animals; however, the mechanism by which the pathogen Burkholderia pseudomallei invades the central nervous system (CNS) remains unclear. B. pseudomallei-loaded Ly6C cells have been suggested as a putative portal; however, during melioidosis, lipopolysaccharide (LPS) can drive disruption of the blood-brain barrier (BBB). This study aims to test whether the Trojan horse-like mechanism occurs during endotoxemia. The expression levels of cerebral cytokines, chemokines and cell adhesion molecules; the activation of astrocytes, microglia and endothelial cells; and the increased vascular permeability and brain-infiltrating leukocytes were evaluated using B. pseudomallei, B. thailandensis, B. cenocepacia and B. multivorans LPS-induced brains. Accordingly, different degrees of BBB damage in those brains with endotoxemia were established. The B. multivorans LPS-induced brain exhibited the highest levels of disruptive BBB according to the above mediators/indicators. Into these distinct groups of endotoxemic mice, B. pseudomallei-loaded Ly6C cells or free B. pseudomallei were adoptively transferred at equal bacterial concentrations (103 CFU). The bacterial load and number of cases of meningeal neutrophil infiltration in the brains of animals treated with B. pseudomallei-loaded Ly6C cells were higher than those in brains induced by free B. pseudomallei in any of the endotoxemic groups. In particular, these results were reproducible in B. multivorans LPS-induced brains. We suggest that B. pseudomallei-loaded cells can act as a Trojan horse and are more effective than free B. pseudomallei in invading the CNS under septic or endotoxemic conditions even when there is a high degree of BBB disruption.
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Price EP, Viberg LT, Kidd TJ, Bell SC, Currie BJ, Sarovich DS. Transcriptomic analysis of longitudinal Burkholderia pseudomallei infecting the cystic fibrosis lung. Microb Genom 2018; 4. [PMID: 29989529 PMCID: PMC6159556 DOI: 10.1099/mgen.0.000194] [Citation(s) in RCA: 26] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/18/2022] Open
Abstract
The melioidosis bacterium, Burkholderia pseudomallei, is increasingly being recognised as a pathogen in patients with cystic fibrosis (CF). We have recently catalogued genome-wide variation of paired, isogenic B. pseudomallei isolates from seven Australasian CF cases, which were collected between 4 and 55 months apart. Here, we extend this investigation by documenting the transcriptomic changes in B. pseudomallei in five cases. Following growth in an artificial CF sputum medium, four of the five paired isolates exhibited significant differential gene expression (DE) that affected between 32 and 792 genes. The greatest number of DE events was observed between the strains from patient CF9, consistent with the hypermutator status of the latter strain, which is deficient in the DNA mismatch repair protein MutS. Two patient isolates harboured duplications that concomitantly increased expression of the β-lactamase-encoding gene penA, and a 35 kb deletion in another abolished expression of 29 genes. Convergent expression profiles in the chronically-adapted isolates identified two significantly downregulated and 17 significantly upregulated loci, including the resistance-nodulation-division (RND) efflux pump BpeEF-OprC, the quorum-sensing hhqABCDE operon, and a cyanide- and pyocyanin-insensitive cytochrome bd quinol oxidase. These convergent pathoadaptations lead to increased expression of pathways that may suppress competing bacterial and fungal pathogens, and that enhance survival in oxygen-restricted environments, the latter of which may render conventional antibiotics less effective in vivo. Treating chronically adapted B. pseudomallei infections with antibiotics designed to target anaerobic infections, such as the nitroimidazole class of antibiotics, may significantly improve pathogen eradication attempts by exploiting this Achilles heel.
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Affiliation(s)
- Erin P Price
- 1Faculty of Science, Health, Education and Engineering, University of the Sunshine Coast, Sippy Downs, QLD, Australia.,2Global and Tropical Health Division, Menzies School of Health Research, Charles Darwin University, Darwin, Northern Territory, Australia
| | - Linda T Viberg
- 2Global and Tropical Health Division, Menzies School of Health Research, Charles Darwin University, Darwin, Northern Territory, Australia
| | - Timothy J Kidd
- 3Faculty of Medicine, The University of Queensland, Brisbane, QLD, Australia.,4School of Chemistry and Molecular Biosciences, The University of Queensland, St Lucia, QLD, Australia
| | - Scott C Bell
- 3Faculty of Medicine, The University of Queensland, Brisbane, QLD, Australia.,5QIMR Berghofer Medical Research Institute, Herston, QLD, Australia.,6Department of Thoracic Medicine, The Prince Charles Hospital, Chermside, QLD, Australia
| | - Bart J Currie
- 2Global and Tropical Health Division, Menzies School of Health Research, Charles Darwin University, Darwin, Northern Territory, Australia.,7Department of Infectious Diseases and Northern Territory Medical Program, Royal Darwin Hospital, Darwin, Northern Territory, Australia
| | - Derek S Sarovich
- 1Faculty of Science, Health, Education and Engineering, University of the Sunshine Coast, Sippy Downs, QLD, Australia.,2Global and Tropical Health Division, Menzies School of Health Research, Charles Darwin University, Darwin, Northern Territory, Australia
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Abstract
Burkholderia pseudomallei is a Gram-negative environmental bacterium and the aetiological agent of melioidosis, a life-threatening infection that is estimated to account for ∼89,000 deaths per year worldwide. Diabetes mellitus is a major risk factor for melioidosis, and the global diabetes pandemic could increase the number of fatalities caused by melioidosis. Melioidosis is endemic across tropical areas, especially in southeast Asia and northern Australia. Disease manifestations can range from acute septicaemia to chronic infection, as the facultative intracellular lifestyle and virulence factors of B. pseudomallei promote survival and persistence of the pathogen within a broad range of cells, and the bacteria can manipulate the host's immune responses and signalling pathways to escape surveillance. The majority of patients present with sepsis, but specific clinical presentations and their severity vary depending on the route of bacterial entry (skin penetration, inhalation or ingestion), host immune function and bacterial strain and load. Diagnosis is based on clinical and epidemiological features as well as bacterial culture. Treatment requires long-term intravenous and oral antibiotic courses. Delays in treatment due to difficulties in clinical recognition and laboratory diagnosis often lead to poor outcomes and mortality can exceed 40% in some regions. Research into B. pseudomallei is increasing, owing to the biothreat potential of this pathogen and increasing awareness of the disease and its burden; however, better diagnostic tests are needed to improve early confirmation of diagnosis, which would enable better therapeutic efficacy and survival.
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Affiliation(s)
- W Joost Wiersinga
- Department of Medicine, Division of Infectious Diseases, Academic Medical Center, Meibergdreef 9, Rm. G2-132, 1105 AZ Amsterdam, The Netherlands
- Centre for Experimental and Molecular Medicine, Academic Medical Center, Amsterdam, The Netherlands
| | - Harjeet S Virk
- Centre for Experimental and Molecular Medicine, Academic Medical Center, Amsterdam, The Netherlands
| | - Alfredo G Torres
- Department of Microbiology and Immunology, University of Texas Medical Branch, Galveston, Texas, USA
| | - Bart J Currie
- Menzies School of Health Research, Charles Darwin University and Royal Darwin Hospital, Darwin, Australia
| | - Sharon J Peacock
- Faculty of Infectious and Tropical Diseases, London School of Hygiene and Tropical Medicine, London, UK
- Department of Medicine, University of Cambridge, Cambridge, UK
| | - David A B Dance
- Faculty of Infectious and Tropical Diseases, London School of Hygiene and Tropical Medicine, London, UK
- Lao-Oxford-Mahosot Hospital Wellcome Trust Research Unit, Vientiane, Lao People's Democratic Republic
- Centre for Tropical Medicine and Global Health, University of Oxford, Oxford, UK
| | - Direk Limmathurotsakul
- Centre for Tropical Medicine and Global Health, University of Oxford, Oxford, UK
- Department of Tropical Hygiene and Mahidol-Oxford Tropical Medicine Research Unit, Faculty of Tropical Medicine, Mahidol University, Bangkok 10400, Thailand
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41
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Relationships Between Resistance and Virulence in Burkholderia pseudomallei. CURRENT TROPICAL MEDICINE REPORTS 2017. [DOI: 10.1007/s40475-017-0119-1] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/26/2022]
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Antibodies against In Vivo-Expressed Antigens Are Sufficient To Protect against Lethal Aerosol Infection with Burkholderia mallei and Burkholderia pseudomallei. Infect Immun 2017; 85:IAI.00102-17. [PMID: 28507073 DOI: 10.1128/iai.00102-17] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/12/2017] [Accepted: 05/08/2017] [Indexed: 12/22/2022] Open
Abstract
Burkholderia mallei, a facultative intracellular bacterium and tier 1 biothreat, causes the fatal zoonotic disease glanders. The organism possesses multiple genes encoding autotransporter proteins, which represent important virulence factors and targets for developing countermeasures in pathogenic Gram-negative bacteria. In the present study, we investigated one of these autotransporters, BatA, and demonstrate that it displays lipolytic activity, aids in intracellular survival, is expressed in vivo, elicits production of antibodies during infection, and contributes to pathogenicity in a mouse aerosol challenge model. A mutation in the batA gene of wild-type strain ATCC 23344 was found to be particularly attenuating, as BALB/c mice infected with the equivalent of 80 median lethal doses cleared the organism. This finding prompted us to test the hypothesis that vaccination with the batA mutant strain elicits protective immunity against subsequent infection with wild-type bacteria. We discovered that not only does vaccination provide high levels of protection against lethal aerosol challenge with B. mallei ATCC 23344, it also protects against infection with multiple isolates of the closely related organism and causative agent of melioidosis, Burkholderia pseudomallei Passive-transfer experiments also revealed that the protective immunity afforded by vaccination with the batA mutant strain is predominantly mediated by IgG antibodies binding to antigens expressed exclusively in vivo Collectively, our data demonstrate that BatA is a target for developing medical countermeasures and that vaccination with a mutant lacking expression of the protein provides a platform to gain insights regarding mechanisms of protective immunity against B. mallei and B. pseudomallei, including antigen discovery.
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Perumal Samy R, Stiles BG, Sethi G, Lim LHK. Melioidosis: Clinical impact and public health threat in the tropics. PLoS Negl Trop Dis 2017; 11:e0004738. [PMID: 28493905 PMCID: PMC5426594 DOI: 10.1371/journal.pntd.0004738] [Citation(s) in RCA: 53] [Impact Index Per Article: 7.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/19/2023] Open
Abstract
This review briefly summarizes the geographical distribution and clinical impact of melioidosis, especially in the tropics. Burkholderia pseudomallei (a gram-negative bacterium) is the major causative agent for melioidosis, which is prevalent in Singapore, Malaysia, Thailand, Vietnam, and Northern Australia. Melioidosis patients are increasingly being recognized in other parts of the world. The bacteria are intrinsically resistant to many antimicrobial agents, but prolonged treatment, especially with combinations of antibiotics, may be effective. Despite therapy, the overall case fatality rate of septicemia in melioidosis remains significantly high. Intracellular survival of the bacteria within macrophages may progress to chronic infections, and about 10% of patients suffer relapses. In the coming decades, melioidosis will increasingly afflict travelers throughout many global regions. Clinicians managing travelers returning from the subtropics or tropics with severe pneumonia or septicemia should consider acute melioidosis as a differential diagnosis. Patients with open skin wounds, diabetes, or chronic renal disease are at higher risk for melioidosis and should avoid direct contact with soil and standing water in endemic regions. Furthermore, there are fears that B. pseudomallei may be used as a biological weapon. Technological advancements in molecular diagnostics and antibiotic therapy are improving the disease outcomes in endemic areas throughout Asia. Research and development efforts on vaccine candidates against melioidosis are ongoing.
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Affiliation(s)
- Ramar Perumal Samy
- Department of Physiology, NUS Immunology Programme, Centre for Life Sciences, Yong Loo Lin School of Medicine, National University Health System (NUHS), National University of Singapore, Singapore
| | - Bradley G. Stiles
- Integrated Toxicology Division, US Army Medical Research Institute of Infectious Diseases, Fort Detrick, Maryland, United States of America
| | - Gautam Sethi
- Department of Pharmacology, Yong Loo Lin School of Medicine, NUHS, National University of Singapore, Singapore
| | - Lina H. K. Lim
- Department of Physiology, NUS Immunology Programme, Centre for Life Sciences, Yong Loo Lin School of Medicine, National University Health System (NUHS), National University of Singapore, Singapore
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Nualnoi T, Norris MH, Tuanyok A, Brett PJ, Burtnick MN, Keim PS, Settles EW, Allender CJ, AuCoin DP. Development of Immunoassays for Burkholderia pseudomallei Typical and Atypical Lipopolysaccharide Strain Typing. Am J Trop Med Hyg 2016; 96:358-367. [PMID: 27994103 PMCID: PMC5303037 DOI: 10.4269/ajtmh.16-0308] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/18/2016] [Accepted: 10/27/2016] [Indexed: 01/31/2023] Open
Abstract
Burkholderia pseudomallei is the causative agent of melioidosis, a severe infection endemic to many tropical regions. Lipopolysaccharide (LPS) is recognized as an important virulence factor used by B. pseudomallei. Isolates of B. pseudomallei have been shown to express one of four different types of LPS (typical LPS, atypical LPS types B and B2, and rough LPS) and in vitro studies have demonstrated that LPS types may impact disease severity. The association between LPS types and clinical manifestations, however, is still unknown, in part because an effective method for LPS type identification is not available. Thus, we developed antigen capture immunoassays capable of distinguishing between the LPS types. Mice were injected with B or B2 LPS for atypical LPS–specific monoclonal antibody (mAb) isolation; only two mAbs (3A2 and 5B4) were isolated from mice immunized with B2 LPS. Immunoblot analysis and surface plasmon resonance demonstrated that 3A2 and 5B4 are reactive with both B2 and B LPS where 3A2 was shown to possess higher affinity. Assays were then developed using capsular polysaccharide–specific mAb 4C4 for bacterial capture and 4C7 (previously shown to bind typical LPS) or 3A2 mAbs for typical or atypical LPS strain detection, respectively. The evaluations performed with 197 strains of Burkholderia and non-Burkholderia species showed that the assays are reactive to B. pseudomallei and Burkholderia mallei strains and have an accuracy of 98.8% (zero false positives and two false negatives) for LPS typing. The results suggest that the assays are effective and applicable for B. pseudomallei LPS typing.
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Affiliation(s)
- Teerapat Nualnoi
- Department of Microbiology and Immunology, University of Nevada School of Medicine, Reno, Nevada
| | - Michael H Norris
- Department of Infectious Diseases and Pathology, University of Florida, Gainesville, Florida
| | - Apichai Tuanyok
- Department of Infectious Diseases and Pathology, University of Florida, Gainesville, Florida
| | - Paul J Brett
- Department of Microbiology and Immunology, University of South Alabama, Mobile, Alabama
| | - Mary N Burtnick
- Department of Microbiology and Immunology, University of South Alabama, Mobile, Alabama
| | - Paul S Keim
- Department of Biological Sciences, Northern Arizona University, Flagstaff, Arizona
| | - Erik W Settles
- Department of Biological Sciences, Northern Arizona University, Flagstaff, Arizona
| | | | - David P AuCoin
- Department of Microbiology and Immunology, University of Nevada School of Medicine, Reno, Nevada
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Memišević V, Kumar K, Zavaljevski N, DeShazer D, Wallqvist A, Reifman J. DBSecSys 2.0: a database of Burkholderia mallei and Burkholderia pseudomallei secretion systems. BMC Bioinformatics 2016; 17:387. [PMID: 27650316 PMCID: PMC5029111 DOI: 10.1186/s12859-016-1242-z] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/20/2016] [Accepted: 09/08/2016] [Indexed: 01/08/2023] Open
Abstract
Background Burkholderia mallei and B. pseudomallei are the causative agents of glanders and melioidosis, respectively, diseases with high morbidity and mortality rates. B. mallei and B. pseudomallei are closely related genetically; B. mallei evolved from an ancestral strain of B. pseudomallei by genome reduction and adaptation to an obligate intracellular lifestyle. Although these two bacteria cause different diseases, they share multiple virulence factors, including bacterial secretion systems, which represent key components of bacterial pathogenicity. Despite recent progress, the secretion system proteins for B. mallei and B. pseudomallei, their pathogenic mechanisms of action, and host factors are not well characterized. Results We previously developed a manually curated database, DBSecSys, of bacterial secretion system proteins for B. mallei. Here, we report an expansion of the database with corresponding information about B. pseudomallei. DBSecSys 2.0 contains comprehensive literature-based and computationally derived information about B. mallei ATCC 23344 and literature-based and computationally derived information about B. pseudomallei K96243. The database contains updated information for 163 B. mallei proteins from the previous database and 61 additional B. mallei proteins, and new information for 281 B. pseudomallei proteins associated with 5 secretion systems, their 1,633 human- and murine-interacting targets, and 2,400 host-B. mallei interactions and 2,286 host-B. pseudomallei interactions. The database also includes information about 13 pathogenic mechanisms of action for B. mallei and B. pseudomallei secretion system proteins inferred from the available literature or computationally. Additionally, DBSecSys 2.0 provides details about 82 virulence attenuation experiments for 52 B. mallei secretion system proteins and 98 virulence attenuation experiments for 61 B. pseudomallei secretion system proteins. We updated the Web interface and data access layer to speed-up users’ search of detailed information for orthologous proteins related to secretion systems of the two pathogens. Conclusions The updates of DBSecSys 2.0 provide unique capabilities to access comprehensive information about secretion systems of B. mallei and B. pseudomallei. They enable studies and comparisons of corresponding proteins of these two closely related pathogens and their host-interacting partners. The database is available at http://dbsecsys.bhsai.org.
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Affiliation(s)
- Vesna Memišević
- Department of Defense Biotechnology High Performance Computing Software Applications Institute, Telemedicine and Advanced Technology Research Center, U.S. Army Medical Research and Materiel Command, Fort Detrick, MD 21702, USA
| | - Kamal Kumar
- Department of Defense Biotechnology High Performance Computing Software Applications Institute, Telemedicine and Advanced Technology Research Center, U.S. Army Medical Research and Materiel Command, Fort Detrick, MD 21702, USA
| | - Nela Zavaljevski
- Department of Defense Biotechnology High Performance Computing Software Applications Institute, Telemedicine and Advanced Technology Research Center, U.S. Army Medical Research and Materiel Command, Fort Detrick, MD 21702, USA
| | - David DeShazer
- Bacteriology Division, U.S. Army Medical Research Institute of Infectious Diseases, Fort Detrick, MD 21702, USA
| | - Anders Wallqvist
- Department of Defense Biotechnology High Performance Computing Software Applications Institute, Telemedicine and Advanced Technology Research Center, U.S. Army Medical Research and Materiel Command, Fort Detrick, MD 21702, USA
| | - Jaques Reifman
- Department of Defense Biotechnology High Performance Computing Software Applications Institute, Telemedicine and Advanced Technology Research Center, U.S. Army Medical Research and Materiel Command, Fort Detrick, MD 21702, USA.
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Sarovich DS, Garin B, De Smet B, Kaestli M, Mayo M, Vandamme P, Jacobs J, Lompo P, Tahita MC, Tinto H, Djaomalaza I, Currie BJ, Price EP. Phylogenomic Analysis Reveals an Asian Origin for African Burkholderia pseudomallei and Further Supports Melioidosis Endemicity in Africa. mSphere 2016; 1:e00089-15. [PMID: 27303718 PMCID: PMC4863585 DOI: 10.1128/msphere.00089-15] [Citation(s) in RCA: 50] [Impact Index Per Article: 6.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/08/2015] [Accepted: 02/05/2016] [Indexed: 12/22/2022] Open
Abstract
Burkholderia pseudomallei, an environmental bacterium that causes the deadly disease melioidosis, is endemic in northern Australia and Southeast Asia. An increasing number of melioidosis cases are being reported in other tropical regions, including Africa and the Indian Ocean islands. B. pseudomallei first emerged in Australia, with subsequent rare dissemination event(s) to Southeast Asia; however, its dispersal to other regions is not yet well understood. We used large-scale comparative genomics to investigate the origins of three B. pseudomallei isolates from Madagascar and two from Burkina Faso. Phylogenomic reconstruction demonstrates that these African B. pseudomallei isolates group into a single novel clade that resides within the more ancestral Asian clade. Intriguingly, South American strains reside within the African clade, suggesting more recent dissemination from West Africa to the Americas. Anthropogenic factors likely assisted in B. pseudomallei dissemination to Africa, possibly during migration of the Austronesian peoples from Indonesian Borneo to Madagascar ~2,000 years ago, with subsequent genetic diversity driven by mutation and recombination. Our study provides new insights into global patterns of B. pseudomallei dissemination and adds to the growing body of evidence of melioidosis endemicity in Africa. Our findings have important implications for melioidosis diagnosis and management in Africa. IMPORTANCE Sporadic melioidosis cases have been reported in the African mainland and Indian Ocean islands, but until recently, these regions were not considered areas where B. pseudomallei is endemic. Given the high mortality rate of melioidosis, it is crucial that this disease be recognized and suspected in all regions of endemicity. Previous work has shown that B. pseudomallei originated in Australia, with subsequent introduction into Asia; however, the precise origin of B. pseudomallei in other tropical regions remains poorly understood. Using whole-genome sequencing, we characterized B. pseudomallei isolates from Madagascar and Burkina Faso. Next, we compared these strains to a global collection of B. pseudomallei isolates to identify their evolutionary origins. We found that African B. pseudomallei strains likely originated from Asia and were closely related to South American strains, reflecting a relatively recent shared evolutionary history. We also identified substantial genetic diversity among African strains, suggesting long-term B. pseudomallei endemicity in this region.
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Affiliation(s)
- Derek S. Sarovich
- Global and Tropical Health Division, Menzies School of Health Research, Darwin, Australia
| | - Benoit Garin
- Bacteriological Unit, Institut Pasteur de Madagascar, Antananarivo, Madagascar
| | - Birgit De Smet
- Department of Clinical Sciences, Institute of Tropical Medicine, Antwerp, Belgium
- Faculty of Sciences, Laboratory of Microbiology, Ghent University, Ghent, Belgium
| | - Mirjam Kaestli
- Global and Tropical Health Division, Menzies School of Health Research, Darwin, Australia
| | - Mark Mayo
- Global and Tropical Health Division, Menzies School of Health Research, Darwin, Australia
| | - Peter Vandamme
- Faculty of Sciences, Laboratory of Microbiology, Ghent University, Ghent, Belgium
| | - Jan Jacobs
- Department of Clinical Sciences, Institute of Tropical Medicine, Antwerp, Belgium
- Department of Microbiology and Immunology, University of Leuven, Leuven, Belgium
| | | | - Marc C. Tahita
- Clinical Research Unit of Nanoro (IRSS-CRUN), Nanoro, Burkina Faso
| | - Halidou Tinto
- Clinical Research Unit of Nanoro (IRSS-CRUN), Nanoro, Burkina Faso
| | | | - Bart J. Currie
- Global and Tropical Health Division, Menzies School of Health Research, Darwin, Australia
| | - Erin P. Price
- Global and Tropical Health Division, Menzies School of Health Research, Darwin, Australia
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Characteristics, clinical outcomes and factors influencing mortality of patients with melioidosis in southern Thailand: A 10-year retrospective study. ASIAN PAC J TROP MED 2016; 9:256-60. [DOI: 10.1016/j.apjtm.2016.01.034] [Citation(s) in RCA: 24] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/15/2015] [Revised: 12/20/2015] [Accepted: 12/30/2015] [Indexed: 11/21/2022] Open
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Bozue JA, Chaudhury S, Amemiya K, Chua J, Cote CK, Toothman RG, Dankmeyer JL, Klimko CP, Wilhelmsen CL, Raymond JW, Zavaljevski N, Reifman J, Wallqvist A. Phenotypic Characterization of a Novel Virulence-Factor Deletion Strain of Burkholderia mallei That Provides Partial Protection against Inhalational Glanders in Mice. Front Cell Infect Microbiol 2016; 6:21. [PMID: 26955620 PMCID: PMC4767903 DOI: 10.3389/fcimb.2016.00021] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/12/2015] [Accepted: 02/01/2016] [Indexed: 01/29/2023] Open
Abstract
Burkholderia mallei (Bm) is a highly infectious intracellular pathogen classified as a category B biological agent by the Centers for Disease Control and Prevention. After respiratory exposure, Bm establishes itself within host macrophages before spreading into major organ systems, which can lead to chronic infection, sepsis, and death. Previously, we combined computational prediction of host-pathogen interactions with yeast two-hybrid experiments and identified novel virulence factor genes in Bm, including BMAA0553, BMAA0728 (tssN), and BMAA1865. In the present study, we used recombinant allelic exchange to construct deletion mutants of BMAA0553 and tssN (ΔBMAA0553 and ΔTssN, respectively) and showed that both deletions completely abrogated virulence at doses of >100 times the LD50 of the wild-type Bm strain. Analysis of ΔBMAA0553- and ΔTssN-infected mice showed starkly reduced bacterial dissemination relative to wild-type Bm, and subsequent in vitro experiments characterized pathogenic phenotypes with respect to intracellular growth, macrophage uptake and phagosomal escape, actin-based motility, and multinucleated giant cell formation. Based on observed in vitro and in vivo phenotypes, we explored the use of ΔTssN as a candidate live-attenuated vaccine. Mice immunized with aerosolized ΔTssN showed a 21-day survival rate of 67% after a high-dose aerosol challenge with the wild-type Bm ATCC 23344 strain, compared to a 0% survival rate for unvaccinated mice. However, analysis of histopathology and bacterial burden showed that while the surviving vaccinated mice were protected from acute infection, Bm was still able to establish a chronic infection. Vaccinated mice showed a modest IgG response, suggesting a limited potential of ΔTssN as a vaccine candidate, but also showed prolonged elevation of pro-inflammatory cytokines, underscoring the role of cellular and innate immunity in mitigating acute infection in inhalational glanders.
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Affiliation(s)
- Joel A Bozue
- Bacteriology Division, United States Army Medical Research Institute of Infectious Diseases Fort Detrick, MD, USA
| | - Sidhartha Chaudhury
- Telemedicine and Advanced Technology Research Center, Biotechnology HPC Software Applications Institute, United States Army Medical Research and Materiel Command Fort Detrick, MD, USA
| | - Kei Amemiya
- Bacteriology Division, United States Army Medical Research Institute of Infectious Diseases Fort Detrick, MD, USA
| | - Jennifer Chua
- Bacteriology Division, United States Army Medical Research Institute of Infectious Diseases Fort Detrick, MD, USA
| | - Christopher K Cote
- Bacteriology Division, United States Army Medical Research Institute of Infectious Diseases Fort Detrick, MD, USA
| | - Ronald G Toothman
- Bacteriology Division, United States Army Medical Research Institute of Infectious Diseases Fort Detrick, MD, USA
| | - Jennifer L Dankmeyer
- Bacteriology Division, United States Army Medical Research Institute of Infectious Diseases Fort Detrick, MD, USA
| | - Christopher P Klimko
- Bacteriology Division, United States Army Medical Research Institute of Infectious Diseases Fort Detrick, MD, USA
| | - Catherine L Wilhelmsen
- Pathology Division, United States Army of Medical Research Institute of Infectious Diseases Fort Detrick, MD, USA
| | - Jolynn W Raymond
- Pathology Division, United States Army of Medical Research Institute of Infectious Diseases Fort Detrick, MD, USA
| | - Nela Zavaljevski
- Telemedicine and Advanced Technology Research Center, Biotechnology HPC Software Applications Institute, United States Army Medical Research and Materiel Command Fort Detrick, MD, USA
| | - Jaques Reifman
- Telemedicine and Advanced Technology Research Center, Biotechnology HPC Software Applications Institute, United States Army Medical Research and Materiel Command Fort Detrick, MD, USA
| | - Anders Wallqvist
- Telemedicine and Advanced Technology Research Center, Biotechnology HPC Software Applications Institute, United States Army Medical Research and Materiel Command Fort Detrick, MD, USA
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Chiang CY, Ulrich RL, Ulrich MP, Eaton B, Ojeda JF, Lane DJ, Kota KP, Kenny TA, Ladner JT, Dickson SP, Kuehl K, Raychaudhuri R, Sun M, Bavari S, Wolcott MJ, Covell D, Panchal RG. Characterization of the murine macrophage response to infection with virulent and avirulent Burkholderia species. BMC Microbiol 2015; 15:259. [PMID: 26545875 PMCID: PMC4636792 DOI: 10.1186/s12866-015-0593-3] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/26/2015] [Accepted: 10/28/2015] [Indexed: 11/10/2022] Open
Abstract
BACKGROUND Burkholderia pseudomallei (Bp) and Burkholderia mallei (Bm) are Gram-negative facultative intracellular pathogens, which are the causative agents of melioidosis and glanders, respectively. Depending on the route of exposure, aerosol or transcutaneous, infection by Bp or Bm can result in an extensive range of disease - from acute to chronic, relapsing illness to fatal septicemia. Both diseases are associated with difficult diagnosis and high fatality rates. About ninety five percent of patients succumb to untreated septicemic infections and the fatality rate is 50 % even when standard antibiotic treatments are administered. RESULTS The goal of this study is to profile murine macrophage-mediated phenotypic and molecular responses that are characteristic to a collection of Bp, Bm, Burkholderia thailandensis (Bt) and Burkholderia oklahomensis (Bo) strains obtained from humans, animals, environment and geographically diverse locations. Burkholderia spp. (N = 21) were able to invade and replicate in macrophages, albeit to varying degrees. All Bp (N = 9) and four Bm strains were able to induce actin polymerization on the bacterial surface following infection. Several Bp and Bm strains showed reduced ability to induce multinucleated giant cell (MNGC) formation, while Bo and Bp 776 were unable to induce this phenotype. Measurement of host cytokine responses revealed a statistically significant Bm mediated IL-6 and IL-10 production compared to Bp strains. Hierarchical clustering of transcriptional data from 84 mouse cytokines, chemokines and their corresponding receptors identified 29 host genes as indicators of differential responses between the Burkholderia spp. Further validation confirmed Bm mediated Il-1b, Il-10, Tnfrsf1b and Il-36a mRNA expressions were significantly higher when compared to Bp and Bt. CONCLUSIONS These results characterize the phenotypic and immunological differences in the host innate response to pathogenic and avirulent Burkholderia strains and provide insight into the phenotypic alterations and molecular targets underlying host-Burkholderia interactions.
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Affiliation(s)
- Chih-Yuan Chiang
- Molecular and Translational Sciences Division, United States Army Medical Research Institute of Infectious Diseases (USAMRIID), Fort Detrick, MD, USA.
| | - Ricky L Ulrich
- Institute for Therapeutic Innovation, Department of Medicine, University of Florida, Orlando, FL, USA.
| | | | - Brett Eaton
- Molecular and Translational Sciences Division, United States Army Medical Research Institute of Infectious Diseases (USAMRIID), Fort Detrick, MD, USA.
| | - Jenifer F Ojeda
- Molecular and Translational Sciences Division, United States Army Medical Research Institute of Infectious Diseases (USAMRIID), Fort Detrick, MD, USA.
| | - Douglas J Lane
- Molecular and Translational Sciences Division, United States Army Medical Research Institute of Infectious Diseases (USAMRIID), Fort Detrick, MD, USA.
| | | | - Tara A Kenny
- Molecular and Translational Sciences Division, United States Army Medical Research Institute of Infectious Diseases (USAMRIID), Fort Detrick, MD, USA.
| | - Jason T Ladner
- Center for Genome Sciences, USAMRIID, Fort Detrick, MD, USA.
| | | | | | | | - Mei Sun
- Pathology Division, USAMRIID, Fort Detrick, MD, USA.
| | - Sina Bavari
- Molecular and Translational Sciences Division, United States Army Medical Research Institute of Infectious Diseases (USAMRIID), Fort Detrick, MD, USA.
| | - Mark J Wolcott
- Diagnostic Systems Division, USAMRIID, Fort Detrick, MD, USA.
| | - David Covell
- Screening Technologies Branch, Developmental Therapeutics Program, National Cancer Institute, Frederick, MD, USA.
| | - Rekha G Panchal
- Molecular and Translational Sciences Division, United States Army Medical Research Institute of Infectious Diseases (USAMRIID), Fort Detrick, MD, USA.
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Gong L, Lai SC, Treerat P, Prescott M, Adler B, Boyce JD, Devenish RJ. Burkholderia pseudomallei type III secretion system cluster 3 ATPase BsaS, a chemotherapeutic target for small-molecule ATPase inhibitors. Infect Immun 2015; 83:1276-85. [PMID: 25605762 PMCID: PMC4363454 DOI: 10.1128/iai.03070-14] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/10/2014] [Accepted: 01/05/2015] [Indexed: 12/18/2022] Open
Abstract
Melioidosis is an infectious disease of high mortality for humans and other animal species; it is prevalent in tropical regions worldwide. The pathogenesis of melioidosis depends on the ability of its causative agent, the Gram-negative bacterium Burkholderia pseudomallei, to enter and survive in host cells. B. pseudomallei can escape from the phagosome into the cytosol of phagocytic cells where it replicates and acquires actin-mediated motility, avoiding killing by the autophagy-dependent process, LC3 (microtubule-associated protein light chain 3)-associated phagocytosis (LAP). The type III secretion system cluster 3 (TTSS3) facilitates bacterial escape from phagosomes, although the mechanism has not been fully elucidated. Given the recent identification of small-molecule inhibitors of the TTSS ATPase, we sought to determine the potential of the predicted TTSS3 ATPase, encoded by bsaS, as a target for chemotherapeutic treatment of infection. A B. pseudomallei bsaS deletion mutant was generated and used as a control against which to assess the effect of inhibitor treatment. Infection of RAW 264.7 cells with wild-type bacteria and subsequent treatment with the ATPase inhibitor compound 939 resulted in reduced intracellular bacterial survival, reduced escape from phagosomes, and increased colocalization with both LC3 and the lysosomal marker LAMP1 (lysosome-associated membrane protein 1). These changes were similar to those observed for infection of RAW 264.7 cells with the bsaS deletion mutant. We propose that treatment with the ATPase inhibitor compound 939 decreased intracellular bacterial survival through a reduced ability of bacteria to escape from phagosomes and increased killing via LAP. Therefore, small-molecule inhibitors of the TTSS3 ATPase have potential as therapeutic treatments against melioidosis.
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Affiliation(s)
- Lan Gong
- Department of Biochemistry and Molecular Biology, Monash University, Victoria, Clayton, Australia Australian Research Council Centre of Excellence in Structural and Functional Microbial Genomics, Monash University, Victoria, Clayton, Australia
| | - Shu-Chin Lai
- Department of Biochemistry and Molecular Biology, Monash University, Victoria, Clayton, Australia
| | - Puthayalai Treerat
- Department of Microbiology, Monash University, Victoria, Clayton, Australia Australian Research Council Centre of Excellence in Structural and Functional Microbial Genomics, Monash University, Victoria, Clayton, Australia
| | - Mark Prescott
- Department of Biochemistry and Molecular Biology, Monash University, Victoria, Clayton, Australia
| | - Ben Adler
- Department of Microbiology, Monash University, Victoria, Clayton, Australia Australian Research Council Centre of Excellence in Structural and Functional Microbial Genomics, Monash University, Victoria, Clayton, Australia
| | - John D Boyce
- Department of Microbiology, Monash University, Victoria, Clayton, Australia Australian Research Council Centre of Excellence in Structural and Functional Microbial Genomics, Monash University, Victoria, Clayton, Australia
| | - Rodney J Devenish
- Department of Biochemistry and Molecular Biology, Monash University, Victoria, Clayton, Australia Australian Research Council Centre of Excellence in Structural and Functional Microbial Genomics, Monash University, Victoria, Clayton, Australia
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