1
|
Cohen-Gihon I, Zaide G, Amit S, Zohar I, Schwartz O, Maor Y, Israeli O, Bilinsky G, Israeli M, Lazar S, Gur D, Aftalion M, Zvi A, Beth-Din A, Bar-Haim E, Elia U, Cohen O, Mamroud E, Chitlaru T. Genome sequence of two novel virulent clinical strains of Burkholderia pseudomallei isolated from acute melioidosis cases imported to Israel from India and Thailand. BMC Genom Data 2024; 25:47. [PMID: 38783201 PMCID: PMC11118722 DOI: 10.1186/s12863-024-01225-x] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/28/2024] [Accepted: 04/12/2024] [Indexed: 05/25/2024] Open
Abstract
OBJECTIVE Burkholderia pseudomallei, the etiological cause of melioidosis, is a soil saprophyte endemic in South-East Asia, where it constitutes a public health concern of high-priority. Melioidosis cases are sporadically identified in nonendemic areas, usually associated with travelers or import of goods from endemic regions. Due to extensive intercontinental traveling and the anticipated climate change-associated alterations of the soil bacterial flora, there is an increasing concern for inadvertent establishment of novel endemic areas, which may expand the global burden of melioidosis. Rapid diagnosis, isolation and characterization of B. pseudomallei isolates is therefore of utmost importance particularly in non-endemic locations. DATA DESCRIPTION We report the genome sequences of two novel clinical isolates (MWH2021 and MST2022) of B. pseudomallei identified in distinct acute cases of melioidosis diagnosed in two individuals arriving to Israel from India and Thailand, respectively. The data includes preliminary genetic analysis of the genomes determining their phylogenetic classification in rapport to the genomes of 131 B. pseudomallei strains documented in the NCBI database. Inspection of the genomic data revealed the presence or absence of loci encoding for several documented virulence determinants involved in the molecular pathogenesis of melioidosis. Virulence analysis in murine models of acute or chronic melioidosis established that both strains belong to the highly virulent class of B. pseudomalleii.
Collapse
Affiliation(s)
- Inbar Cohen-Gihon
- Department of Biochemistry and Molecular Genetics, Institute for Biological Research, Ness-Ziona, Israel
| | - Galia Zaide
- Department of Biochemistry and Molecular Genetics, Institute for Biological Research, Ness-Ziona, Israel
| | - Sharon Amit
- Clinical Microbiology, Sheba Medical Center, Tel Hashomer, Israel
- Faculty of Medicine, Tel-Aviv University, Tel-Aviv, Israel
| | - Iris Zohar
- Faculty of Medicine, Tel-Aviv University, Tel-Aviv, Israel
- Infectious Disease Unit, Wolfson Medical Center, Holon, Israel
| | - Orna Schwartz
- Microbiology and Immunology Laboratory Wolfson Medical Center, Holon, Israel
| | - Yasmin Maor
- Faculty of Medicine, Tel-Aviv University, Tel-Aviv, Israel
- Infectious Disease Unit, Wolfson Medical Center, Holon, Israel
| | - Ofir Israeli
- Department of Biochemistry and Molecular Genetics, Institute for Biological Research, Ness-Ziona, Israel
| | - Gal Bilinsky
- Department of Biochemistry and Molecular Genetics, Institute for Biological Research, Ness-Ziona, Israel
| | - Ma'ayan Israeli
- Department of Biochemistry and Molecular Genetics, Institute for Biological Research, Ness-Ziona, Israel
| | - Shirley Lazar
- Department of Biochemistry and Molecular Genetics, Institute for Biological Research, Ness-Ziona, Israel
| | - David Gur
- Department of Biochemistry and Molecular Genetics, Institute for Biological Research, Ness-Ziona, Israel
| | - Moshe Aftalion
- Department of Biochemistry and Molecular Genetics, Institute for Biological Research, Ness-Ziona, Israel
| | - Anat Zvi
- Department of Biochemistry and Molecular Genetics, Institute for Biological Research, Ness-Ziona, Israel
| | - Adi Beth-Din
- Department of Biochemistry and Molecular Genetics, Institute for Biological Research, Ness-Ziona, Israel
| | - Erez Bar-Haim
- Department of Biochemistry and Molecular Genetics, Institute for Biological Research, Ness-Ziona, Israel
| | - Uri Elia
- Department of Biochemistry and Molecular Genetics, Institute for Biological Research, Ness-Ziona, Israel
| | - Ofer Cohen
- Department of Biochemistry and Molecular Genetics, Institute for Biological Research, Ness-Ziona, Israel
| | - Emanuelle Mamroud
- Department of Biochemistry and Molecular Genetics, Institute for Biological Research, Ness-Ziona, Israel
| | - Theodor Chitlaru
- Department of Biochemistry and Molecular Genetics, Institute for Biological Research, Ness-Ziona, Israel.
- Faculty of Digital Technologies in Medicine, Holon Institute of Technology, Holon, Israel.
| |
Collapse
|
2
|
DÜLGER D, EKİCİ S, DEMİRCİ M, YİĞİN A, BABACAN O. Tracking the footsteps of Burkholderia mallei: determination of the molecular differences and potential resistance genes. Turk J Med Sci 2023; 54:16-25. [PMID: 38812620 PMCID: PMC11031151 DOI: 10.55730/1300-0144.5761] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/21/2023] [Revised: 02/15/2024] [Accepted: 12/21/2023] [Indexed: 05/31/2024] Open
Abstract
Background/aim Chemical biological radiological nuclear threats are at an important point in the agenda of world health today, as they can cause mass deaths. B. mallei attracts attention as a potential biological warfare agent due to its features such as multidrug resistance, a rapid transmission mechanism via aerosol, the absence of a complete treatment protocol for the infection it causes, and the absence of an approved vaccine for protection against the bacteria. B. mallei suspect samples must be studied by experienced personnel in biosafety level III laboratories. B mallei is a difficult and troublesome pathogen to diagnose and many unknowns about B. mallei today. Therefore, the aim of the study was to determine the molecular differences and potential resistance genes of B mallei strains. Materials and methods Determination of the molecular differences and potential resistance genes of B mallei strains with new bioinformatics approaches by comparatively examining the data of 29 B mallei strains, 10 of which were isolated from Türkiye, on the genome list of the National Biotechnology Information Center (NCBI). Results According to the genome annotations of the origins, the origin containing the highest number of CDS which is 5172 was found as the 11th strain obtained in Türkiye in 1949. The origin with the highest number of pseudogenes was determined as 23,344 (China 7) origin. Two hundred and eighty-five pseudogenes found in this strain were obtained from a knee effusion in Myanmar. According to chromosome 2 data, B. mallei strain was determined as the most similar strain to ATCC 23344, line 11 with NCTC 10229 strain, and SAVP1 strain was determined as the least similar strain. When the antimicrobial resistance gene markers of the isolates included in the study were examined, amrA and amrB, qacG ade, Burkholderia pseudomallei Omp38 were found to be carrying. Conclusion In terms of public health, it was thought that the data obtained as a result of our study about B mallei, which is defined as a biological weapon, is very valuable for creating treatment protocols to be applied to possible epidemics in the future. In addition, the available genetic epidemiological data of these strains belonging to a category that is dangerous to work with in a laboratory environment were reviewed.
Collapse
Affiliation(s)
- Dilek DÜLGER
- Department of Medical Microbiology, Faculty of Medicine, Karabük University, Karabük,
Turkiye
| | - Seda EKİCİ
- Republic of Türkiye, the Ministry of Agriculture and Forestry, Veterinary Control Central Research Institute, Ankara,
Turkiye
| | - Mehmet DEMİRCİ
- Department of Medical Microbiology, Faculty of Medicine, Kırklareli University, Kırklareli,
Turkiye
| | - Akın YİĞİN
- Department of Genetics, Faculty of Veterinary, Harran University, Şanlıurfa,
Turkiye
| | - Orkun BABACAN
- Department of Veterinary, Kepsut Vocational School, Balıkesir University, Balıkesir,
Turkiye
| |
Collapse
|
3
|
Kim E, Jung HI, Park SH, Kim HY, Kim SK. Comprehensive genome analysis of Burkholderia contaminans SK875, a quorum-sensing strain isolated from the swine. AMB Express 2023; 13:30. [PMID: 36899131 PMCID: PMC10006387 DOI: 10.1186/s13568-023-01537-8] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/13/2022] [Accepted: 03/04/2023] [Indexed: 03/12/2023] Open
Abstract
The Burkholderia cepacia complex (BCC) is a Gram-negative bacterial, including Burkholderia contaminans species. Although the plain Burkholderia is pervasive from taxonomic and genetic perspectives, a common characteristic is that they may use the quorum-sensing (QS) system. In our previous study, we generated the complete genome sequence of Burkholderia contaminans SK875 isolated from the respiratory tract. To our knowledge, this is the first study to report functional genomic features of B. contaminans SK875 for understanding the pathogenic characteristics. In addition, comparative genomic analysis for five B. contaminans genomes was performed to provide comprehensive information on the disease potential of B. contaminans species. Analysis of average nucleotide identity (ANI) showed that the genome has high similarity (> 96%) with other B. contaminans strains. Five B. contaminans genomes yielded a pangenome of 8832 coding genes, a core genome of 5452 genes, the accessory genome of 2128 genes, and a unique genome of 1252 genes. The 186 genes were specific to B. contaminans SK875, including toxin higB-2, oxygen-dependent choline dehydrogenase, and hypothetical proteins. Genotypic analysis of the antimicrobial resistance of B. contaminans SK875 verified resistance to tetracycline, fluoroquinolone, and aminoglycoside. Compared with the virulence factor database, we identified 79 promising virulence genes such as adhesion system, invasions, antiphagocytic, and secretion systems. Moreover, 45 genes of 57 QS-related genes that were identified in B. contaminans SK875 indicated high sequence homology with other B. contaminans strains. Our results will help to gain insight into virulence, antibiotic resistance, and quorum sensing for B. contaminans species.
Collapse
Affiliation(s)
- Eiseul Kim
- Institute of Life Sciences & Resources and Department of Food Science and Biotechnology, Kyung Hee University, Yongin, 17104, Korea
| | - Hae-In Jung
- Department of Animal Sciences and Technology, Konkuk University, Seoul, 05029, Korea
| | - Si Hong Park
- Department of Food Science and Technology, Oregon State University, Corvallis, OR, 97331, USA
| | - Hae-Yeong Kim
- Institute of Life Sciences & Resources and Department of Food Science and Biotechnology, Kyung Hee University, Yongin, 17104, Korea.
| | - Soo-Ki Kim
- Department of Animal Sciences and Technology, Konkuk University, Seoul, 05029, Korea.
| |
Collapse
|
4
|
Vitamin D (1α,25(OH)2D3) supplementation minimized multinucleated giant cells formation and inflammatory response during Burkholderia pseudomallei infection in human lung epithelial cells. PLoS One 2023; 18:e0280944. [PMID: 36758060 PMCID: PMC9910702 DOI: 10.1371/journal.pone.0280944] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/02/2022] [Accepted: 01/11/2023] [Indexed: 02/10/2023] Open
Abstract
Melioidosis is an infectious disease with high mortality rates in human, caused by the bacterium Burkholderia pseudomallei. As an intracellular pathogen, B. pseudomallei can escape from the phagosome and induce multinucleated giant cells (MNGCs) formation resulting in antibiotic resistance and immune evasion. A novel strategy to modulate host response against B. pseudomallei pathogenesis is required. In this study, an active metabolite of vitamin D3 (1α,25-dihydroxyvitamin D3 or 1α,25(OH)2D3) was selected to interrupt pathogenesis of B. pseudomallei in a human lung epithelium cell line, A549. The results demonstrated that pretreatment with 10-6 M 1α,25(OH)2D3 could reduce B. pseudomallei internalization to A549 cells at 4 h post infection (P < 0.05). Interestingly, the presence of 1α,25(OH)2D3 gradually reduced MNGC formation at 8, 10 and 12 h compared to that of the untreated cells (P < 0.05). Furthermore, pretreatment with 10-6 M 1α,25(OH)2D3 considerably increased hCAP-18/LL-37 mRNA expression (P < 0.001). Additionally, pro-inflammatory cytokines, including MIF, PAI-1, IL-18, CXCL1, CXCL12 and IL-8, were statistically decreased (P < 0.05) in 10-6 M 1α,25(OH)2D3-pretreated A549 cells by 12 h post-infection. Taken together, this study indicates that pretreatment with 10-6 M 1α,25(OH)2D3 has the potential to reduce the internalization of B. pseudomallei into host cells, decrease MNGC formation and modulate host response during B. pseudomallei infection by minimizing the excessive inflammatory response. Therefore, 1α,25(OH)2D3 supplement may provide an effective supportive treatment for melioidosis patients to combat B. pseudomallei infection and reduce inflammation in these patients.
Collapse
|
5
|
Sun Z, Heacock-Kang Y, McMillan IA, Cabanas D, Zarzycki-Siek J, Hoang TT. A virulence activator of a surface attachment protein in Burkholderia pseudomallei acts as a global regulator of other membrane-associated virulence factors. Front Microbiol 2023; 13:1063287. [PMID: 36726566 PMCID: PMC9884982 DOI: 10.3389/fmicb.2022.1063287] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/06/2022] [Accepted: 12/30/2022] [Indexed: 01/19/2023] Open
Abstract
Burkholderia pseudomallei (Bp), causing a highly fatal disease called melioidosis, is a facultative intracellular pathogen that attaches and invades a variety of cell types. We previously identified BP1026B_I0091 as a surface attachment protein (Sap1) and an essential virulence factor, contributing to Bp pathogenesis in vitro and in vivo. The expression of sap1 is regulated at different stages of Bp intracellular lifecycle by unidentified regulator(s). Here, we identified SapR (BP1026B_II1046) as a transcriptional regulator that activates sap1, using a high-throughput transposon mutagenesis screen in combination with Tn-Seq. Consistent with phenotypes of the Δsap1 mutant, the ΔsapR activator mutant exhibited a significant reduction in Bp attachment to the host cell, leading to subsequent decreased intracellular replication. RNA-Seq analysis further revealed that SapR regulates sap1. The regulation of sap1 by SapR was confirmed quantitatively by qRT-PCR, which also validated the RNA-Seq data. SapR globally regulates genes associated with the bacterial membrane in response to diverse environments, and some of the genes regulated by SapR are virulence factors that are required for Bp intracellular infection (e.g., type III and type VI secretion systems). This study has identified the complex SapR regulatory network and its importance as an activator of an essential Sap1 attachment factor.
Collapse
Affiliation(s)
- Zhenxin Sun
- School of Life Sciences, University of Hawai'i at Mānoa, Honolulu, HI, United States
| | - Yun Heacock-Kang
- School of Life Sciences, University of Hawai'i at Mānoa, Honolulu, HI, United States
| | - Ian A McMillan
- School of Life Sciences, University of Hawai'i at Mānoa, Honolulu, HI, United States
| | - Darlene Cabanas
- School of Life Sciences, University of Hawai'i at Mānoa, Honolulu, HI, United States
| | - Jan Zarzycki-Siek
- School of Life Sciences, University of Hawai'i at Mānoa, Honolulu, HI, United States
| | - Tung T Hoang
- School of Life Sciences, University of Hawai'i at Mānoa, Honolulu, HI, United States
| |
Collapse
|
6
|
Abstract
The soil saprophyte, Burkholderia pseudomallei, is the causative agent of melioidosis, a disease endemic in South East Asia and northern Australia. Exposure to B. pseudomallei by either inhalation or inoculation can lead to severe disease. B. pseudomallei rapidly shifts from an environmental organism to an aggressive intracellular pathogen capable of rapidly spreading around the body. The expression of multiple virulence factors at every stage of intracellular infection allows for rapid progression of infection. Following invasion or phagocytosis, B. pseudomallei resists host-cell killing mechanisms in the phagosome, followed by escape using the type III secretion system. Several secreted virulence factors manipulate the host cell, while bacterial cells undergo a shift in energy metabolism allowing for overwhelming intracellular replication. Polymerisation of host cell actin into “actin tails” propels B. pseudomallei to the membranes of host cells where the type VI secretion system fuses host cells into multinucleated giant cells (MNGCs) to facilitate cell-to-cell dissemination. This review describes the various mechanisms used by B. pseudomallei to survive within cells.
Collapse
Affiliation(s)
- Nicole M Bzdyl
- The Marshall Centre for Infectious Diseases Research and Training, School of Biomedical Sciences, University of Western Australia, Perth, Western Australia, 6009, Australia
| | - Clare L Moran
- The Marshall Centre for Infectious Diseases Research and Training, School of Biomedical Sciences, University of Western Australia, Perth, Western Australia, 6009, Australia
| | - Justine Bendo
- The Marshall Centre for Infectious Diseases Research and Training, School of Biomedical Sciences, University of Western Australia, Perth, Western Australia, 6009, Australia
| | - Mitali Sarkar-Tyson
- The Marshall Centre for Infectious Diseases Research and Training, School of Biomedical Sciences, University of Western Australia, Perth, Western Australia, 6009, Australia
| |
Collapse
|
7
|
Zhu R, Mathur V. Prophages Present in Acinetobacter pittii Influence Bacterial Virulence, Antibiotic Resistance, and Genomic Rearrangements. PHAGE (NEW ROCHELLE, N.Y.) 2022; 3:38-49. [PMID: 36161193 PMCID: PMC9041518 DOI: 10.1089/phage.2021.0014] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/12/2022]
Abstract
Introduction: Antibiotic resistance and virulence are common among bacterial populations, posing a global clinical challenge. The bacterial species Acinetobacter pittii, an infectious agent in clinical environments, has shown increasing rates of antibiotic resistance. Viruses that integrate as prophages into A. pittii could be a potential cause of this pathogenicity, as they often contain antibiotic resistance or virulence factor gene sequences. Methods: In this study, we analyzed 25 A. pittii strains for potential prophages. Using virulence factor databases, we identified many common and virulent prophages in A. pittii. Results: The analysis also included a specific catalogue of the virulence factors and antibiotic resistance genes contributed by A. pittii prophages. Finally, our results illustrate multiple similarities between A. pittii and its bacterial relatives with regard to prophage integration sites and prevalence. Discussion: These findings provide a broader insight into prophage behavior that can be applied to future studies on similar species in the Acinetobacter calcoaceticus-baumannii complex.
Collapse
Affiliation(s)
| | - Vinayak Mathur
- Department of Science, Cabrini University, Radnor, Pennsylvania, USA.,Address correspondence to: Vinayak Mathur, PhD, Department of Science, Cabrini University, 610 King of Prussia Road, IAD 224, Radnor, PA 19087-3698, USA
| |
Collapse
|
8
|
Shafiq M, Ke B, Li X, Zeng M, Yuan Y, He D, Deng X, Jiao X. Genomic diversity of resistant and virulent factors of Burkholderia pseudomallei clinical strains recovered from Guangdong using whole genome sequencing. Front Microbiol 2022; 13:980525. [PMID: 36386717 PMCID: PMC9649843 DOI: 10.3389/fmicb.2022.980525] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/28/2022] [Accepted: 10/04/2022] [Indexed: 02/05/2023] Open
Abstract
BACKGROUND Burkholderia pseudomallei (B. pseudomallei) is a highly infectious agent and causes melioidosis, in both humans and animals, which is endemic in Southeast Asia and Northern Australia. OBJECTIVES This study aims to determine the molecular epidemiology, resistant determinants, and genomic diversity of the clinical isolates of B. pseudomallei to further elucidate the phylogenetic and evolutionary relationship of the strains with those in other endemic regions. METHODS In this study, we obtained eight clinical B. pseudomallei isolates from Guangdong province from 2018 to 2019. All the isolates were sequenced using the Illumina NovaSeq platform. The draft genomes of B. pseudomallei were further used to find antibiotic-resistant genes (ARGs), virulence factors, and gene mutations. Multilocus sequence typing (MLST) and single nucleotide polymorphism (SNP) analysis were performed to characterize the diversity and epidemiology of the strains. RESULTS All isolates were susceptible to antibiotics commonly used for melioidosis treatment. Class D beta-lactamases genes OXA-57 and OXA-59, as well as various mutation factors such as amrA, amrB, omp38, gyrA, and ceoB were identified. MLST analysis of the B. pseudomallei strains identified eight different sequence types (STs): ST1774, ST1775, ST271, ST562, ST46, ST830, ST1325, and ST10. Phylogenetic analysis found that the strains used in this study showed high genetic diversity. We also report 165 virulence factors among B. pseudomallei strains responsible for different neurological disorders, pneumonia, skin lesions, and abscesses. All strains recovered in this study were susceptible to commonly used antibiotics. However, high genetic diversity exists among the isolates. The surveillance, diagnosis, and clinical features of melioidosis varied in different geographical locations. These regional differences in the clinical manifestations have implications for the practical management of the disease. CONCLUSION The present study reports the identification of different mutation and virulence factors among B. pseudomallei strains responsible for different neurological disorders, pneumonia, skin lesions, and abscesses.
Collapse
Affiliation(s)
- Muhammad Shafiq
- Department of Cell Biology and Genetics, Shantou University Medical College, Shantou, China
| | - Bixia Ke
- Center for Disease Control and Prevention of Guangdong Province, Chinese Academy of Sciences, Guangzhou, China
| | - Xin Li
- Department of Cell Biology and Genetics, Shantou University Medical College, Shantou, China
| | - Mi Zeng
- Department of Cell Biology and Genetics, Shantou University Medical College, Shantou, China
| | - Yumeng Yuan
- Department of Cell Biology and Genetics, Shantou University Medical College, Shantou, China
| | - Dongmei He
- Center for Disease Control and Prevention of Guangdong Province, Chinese Academy of Sciences, Guangzhou, China
| | - Xiaoling Deng
- Center for Disease Control and Prevention of Guangdong Province, Chinese Academy of Sciences, Guangzhou, China
- *Correspondence: Xiaoling Deng,
| | - Xiaoyang Jiao
- Department of Cell Biology and Genetics, Shantou University Medical College, Shantou, China
- Xiaoyang Jiao,
| |
Collapse
|
9
|
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 2021; 11:1024-1040. [PMID: 32799724 PMCID: PMC7567441 DOI: 10.1080/21505594.2020.1804275] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [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.
Collapse
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
| |
Collapse
|
10
|
Paulitsch F, Dos Reis FB, Hungria M. Twenty years of paradigm-breaking studies of taxonomy and symbiotic nitrogen fixation by beta-rhizobia, and indication of Brazil as a hotspot of Paraburkholderia diversity. Arch Microbiol 2021; 203:4785-4803. [PMID: 34245357 DOI: 10.1007/s00203-021-02466-5] [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: 04/22/2021] [Revised: 06/11/2021] [Accepted: 06/25/2021] [Indexed: 10/20/2022]
Abstract
Twenty years ago, the first members of the genus Burkholderia capable of nodulating and fixing N2 during symbiosis with leguminous plants were reported. The discovery that β-proteobacteria could nodulate legumes represented a breakthrough event because, for over 100 years, it was thought that all rhizobia belonged exclusively to the α-Proteobacteria class. Over the past 20 years, efforts toward robust characterization of these bacteria with large-scale phylogenomic and taxonomic studies have led to the separation of clinically important and phytopathogenic members of Burkholderia from environmental ones, and the symbiotic nodulating species are now included in the genera Paraburkholderia and Trinickia. Paraburkholderia encompasses the vast majority of β-rhizobia and has been mostly found in South America and South Africa, presenting greater symbiotic affinity with native members of the families Mimosoideae and Papilionoideae, respectively. Being the main center of Mimosa spp. diversity, Brazil is also known as the center of symbiotic Paraburkholderia diversity. Of the 21 symbiotic Paraburkholderia species described to date, 11 have been isolated in Brazil, and others first isolated in different countries have also been found in this country. Additionally, besides the symbiotic N2-fixation capacity of some of its members, Paraburkholderia is considered rich in other beneficial interactions with plants and can promote growth through several direct and indirect mechanisms. Therefore, these bacteria can be considered biological resources employed as environmentally friendly alternatives that could reduce the agricultural dependence on agrochemical inputs.
Collapse
Affiliation(s)
- Fabiane Paulitsch
- Embrapa Soja, C.P. 231, Londrina, Paraná, 86001-970, Brazil.,Departamento de Microbiologia, Universidade Estadual de Londrina, C.P. 10011, Londrina, Paraná, 86057-970, Brazil.,Coordenação de Aperfeiçoamento de Pessoal de Nível Superior, SBN, Quadra 2, Bloco L, Lote 06, Edifício Capes, Brasília, Distrito Federal, 70040-020, Brazil
| | | | - Mariangela Hungria
- Embrapa Soja, C.P. 231, Londrina, Paraná, 86001-970, Brazil. .,Departamento de Microbiologia, Universidade Estadual de Londrina, C.P. 10011, Londrina, Paraná, 86057-970, Brazil.
| |
Collapse
|
11
|
Chomkatekaew C, Boonklang P, Sangphukieo A, Chewapreecha C. An Evolutionary Arms Race Between Burkholderia pseudomallei and Host Immune System: What Do We Know? Front Microbiol 2021; 11:612568. [PMID: 33552023 PMCID: PMC7858667 DOI: 10.3389/fmicb.2020.612568] [Citation(s) in RCA: 7] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/30/2020] [Accepted: 12/21/2020] [Indexed: 12/18/2022] Open
Abstract
A better understanding of co-evolution between pathogens and hosts holds promise for better prevention and control strategies. This review will explore the interactions between Burkholderia pseudomallei, an environmental and opportunistic pathogen, and the human host immune system. B. pseudomallei causes "Melioidosis," a rapidly fatal tropical infectious disease predicted to affect 165,000 cases annually worldwide, of which 89,000 are fatal. Genetic heterogeneities were reported in both B. pseudomallei and human host population, some of which may, at least in part, contribute to inter-individual differences in disease susceptibility. Here, we review (i) a multi-host-pathogen characteristic of the interaction; (ii) selection pressures acting on B. pseudomallei and human genomes with the former being driven by bacterial adaptation across ranges of ecological niches while the latter are driven by human encounter of broad ranges of pathogens; (iii) the mechanisms that generate genetic diversity in bacterial and host population particularly in sequences encoding proteins functioning in host-pathogen interaction; (iv) reported genetic and structural variations of proteins or molecules observed in B. pseudomallei-human host interactions and their implications in infection outcomes. Together, these predict bacterial and host evolutionary trajectory which continues to generate genetic diversity in bacterium and operates host immune selection at the molecular level.
Collapse
Affiliation(s)
| | | | - Apiwat Sangphukieo
- Mahidol-Oxford Tropical Medicine Research Unit (MORU), Bangkok, Thailand
- Bioinformatics and Systems Biology Program, School of Bioresource and Technology, King Mongkut’s University of Technology Thonburi, Bangkok, Thailand
| | - Claire Chewapreecha
- Mahidol-Oxford Tropical Medicine Research Unit (MORU), Bangkok, Thailand
- Bioinformatics and Systems Biology Program, School of Bioresource and Technology, King Mongkut’s University of Technology Thonburi, Bangkok, Thailand
- Wellcome Sanger Institute, Hinxton, United Kingdom
| |
Collapse
|
12
|
Hansen EB, Marcatili P. Modeled Structure of the Cell Envelope Proteinase of Lactococcus lactis. Front Bioeng Biotechnol 2021; 8:613986. [PMID: 33415101 PMCID: PMC7783315 DOI: 10.3389/fbioe.2020.613986] [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: 10/04/2020] [Accepted: 12/02/2020] [Indexed: 11/23/2022] Open
Abstract
The cell envelope proteinase (CEP) of Lactococcus lactis is a large extracellular protease covalently linked to the peptidoglycan of the cell wall. Strains of L. lactis are typically auxotrophic for several amino acids and in order to grow to high cell densities in milk they need an extracellular protease. The structure of the entire CEP enzyme is difficult to determine experimentally due to the large size and due to the attachment to the cell surface. We here describe the use of a combination of structure prediction tools to create a structural model for the entire CEP enzyme of Lactococcus lactis. The model has implications for how the bacterium interacts with casein micelles during growth in milk, and it has implications regarding the energetics of the proteolytic system. Our model for the CEP indicates that the catalytic triad is activated through a structural change caused by interaction with the substrate. The CEP of L. lactis might become a useful model for the mode of action for enzymes belonging to the large class of S8 proteinases with a PA (protease associated) domain and a downstream fibronectin like domain.
Collapse
Affiliation(s)
- Egon Bech Hansen
- National Food Institute, Technical University of Denmark, Kongens Lyngby, Demark
| | - Paolo Marcatili
- Department of Health Technology, Technical University of Denmark, Kongens Lyngby, Demark
| |
Collapse
|
13
|
Sangsri T, Saiprom N, Tubsuwan A, Monk P, Partridge LJ, Chantratita N. Tetraspanins are involved in Burkholderia pseudomallei-induced cell-to-cell fusion of phagocytic and non-phagocytic cells. Sci Rep 2020; 10:17972. [PMID: 33087788 PMCID: PMC7577983 DOI: 10.1038/s41598-020-74737-y] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/27/2020] [Accepted: 09/29/2020] [Indexed: 11/09/2022] Open
Abstract
Tetraspanins are four-span transmembrane proteins of host cells that facilitate infections by many pathogens. Burkholderia pseudomallei is an intracellular bacterium and the causative agent of melioidosis, a severe disease in tropical regions. This study investigated the role of tetraspanins in B. pseudomallei infection. We used flow cytometry to determine tetraspanins CD9, CD63, and CD81 expression on A549 and J774A.1 cells. Their roles in B. pseudomallei infection were investigated in vitro using monoclonal antibodies (MAbs) and recombinant large extracellular loop (EC2) proteins to pretreat cells before infection. Knockout of CD9 and CD81 in cells was performed using CRISPR Cas9 to confirm the role of tetraspanins. Pretreatment of A549 cells with MAb against CD9 and CD9-EC2 significantly enhanced B. pseudomallei internalization, but MAb against CD81 and CD81-EC2 inhibited MNGC formation. Reduction of MNGC formation was consistently observed in J774.A1 cells pretreated with MAbs specific to CD9 and CD81 and with CD9-EC2 and CD81-EC2. Data from knockout experiments confirmed that CD9 enhanced bacterial internalization and that CD81 inhibited MNGC formation. Our data indicate that tetraspanins are host cellular factors that mediated internalization and membrane fusion during B. pseudomallei infection. Tetraspanins may be the potential therapeutic targets for melioidosis.
Collapse
Affiliation(s)
- Tanes Sangsri
- Department of Microbiology and Immunology, Faculty of Tropical Medicine, Mahidol University, 420/6 Rajvithi Road, Bangkok, 10400, Thailand
| | - Natnaree Saiprom
- Department of Microbiology and Immunology, Faculty of Tropical Medicine, Mahidol University, 420/6 Rajvithi Road, Bangkok, 10400, Thailand
| | - Alisa Tubsuwan
- Institute of Molecular Biosciences, Mahidol University, Nakhon Pathom, 73170, Thailand
| | - Peter Monk
- Department of Infection, Immunity and Cardiovascular Disease, School of Medicine, University of Sheffield, Beech Hill Road, Sheffield, S10 2RX, UK
| | - Lynda J Partridge
- Department of Molecular Biology and Biotechnology, University of Sheffield, Western Bank, Sheffield, S10 2TN, UK
| | - Narisara Chantratita
- Department of Microbiology and Immunology, Faculty of Tropical Medicine, Mahidol University, 420/6 Rajvithi Road, Bangkok, 10400, Thailand.
- Mahidol-Oxford Tropical Medicine Research Unit, Faculty of Tropical Medicine, Mahidol University, Bangkok, 10400, Thailand.
| |
Collapse
|
14
|
Berry SB, Haack AJ, Theberge AB, Brighenti S, Svensson M. Host and Pathogen Communication in the Respiratory Tract: Mechanisms and Models of a Complex Signaling Microenvironment. Front Med (Lausanne) 2020; 7:537. [PMID: 33015094 PMCID: PMC7511576 DOI: 10.3389/fmed.2020.00537] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/24/2020] [Accepted: 07/29/2020] [Indexed: 01/15/2023] Open
Abstract
Chronic lung diseases are a leading cause of morbidity and mortality across the globe, encompassing a diverse range of conditions from infections with pathogenic microorganisms to underlying genetic disorders. The respiratory tract represents an active interface with the external environment having the primary immune function of resisting pathogen intrusion and maintaining homeostasis in response to the myriad of stimuli encountered within its microenvironment. To perform these vital functions and prevent lung disorders, a chemical and biological cross-talk occurs in the complex milieu of the lung that mediates and regulates the numerous cellular processes contributing to lung health. In this review, we will focus on the role of cross-talk in chronic lung infections, and discuss how different cell types and signaling pathways contribute to the chronicity of infection(s) and prevent effective immune clearance of pathogens. In the lung microenvironment, pathogens have developed the capacity to evade mucosal immunity using different mechanisms or virulence factors, leading to colonization and infection of the host; such mechanisms include the release of soluble and volatile factors, as well as contact dependent (juxtracrine) interactions. We explore the diverse modes of communication between the host and pathogen in the lung tissue milieu in the context of chronic lung infections. Lastly, we review current methods and approaches used to model and study these host-pathogen interactions in vitro, and the role of these technological platforms in advancing our knowledge about chronic lung diseases.
Collapse
Affiliation(s)
- Samuel B Berry
- Department of Medicine, Center for Infectious Medicine, Karolinska Institutet, Karolinska University Hospital, Stockholm, Sweden.,Department of Chemistry, University of Washington, Seattle, WA, United States
| | - Amanda J Haack
- Department of Chemistry, University of Washington, Seattle, WA, United States
| | - Ashleigh B Theberge
- Department of Chemistry, University of Washington, Seattle, WA, United States
| | - Susanna Brighenti
- Department of Medicine, Center for Infectious Medicine, Karolinska Institutet, Karolinska University Hospital, Stockholm, Sweden
| | - Mattias Svensson
- Department of Medicine, Center for Infectious Medicine, Karolinska Institutet, Karolinska University Hospital, Stockholm, Sweden
| |
Collapse
|
15
|
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.
Collapse
|
16
|
Jitprasutwit S, Jitprasutwit N, Hemsley CM, Onlamoon N, Withatanung P, Muangsombut V, Vattanaviboon P, Stevens JM, Ong C, Stevens MP, Titball RW, Korbsrisate S. Identification of Burkholderia pseudomallei Genes Induced During Infection of Macrophages by Differential Fluorescence Induction. Front Microbiol 2020; 11:72. [PMID: 32153515 PMCID: PMC7047822 DOI: 10.3389/fmicb.2020.00072] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/30/2019] [Accepted: 01/14/2020] [Indexed: 12/05/2022] Open
Abstract
Burkholderia pseudomallei, the causative agent of melioidosis, can survive and replicate in macrophages. Little is known about B. pseudomallei genes that are induced during macrophage infection. We constructed a B. pseudomallei K96243 promoter trap library with genomic DNA fragments fused to the 5' end of a plasmid-borne gene encoding enhanced green fluorescent protein (eGFP). Microarray analysis showed that the library spanned 88% of the B. pseudomallei genome. The recombinant plasmids were introduced into Burkholderia thailandensis E264, and promoter fusions active during in vitro culture were removed. J774A.1 murine macrophages were infected with the promoter trap library, and J774A.1 cells containing fluorescent bacteria carrying plasmids with active promoters were isolated using flow cytometric-based cell sorting. Candidate macrophage-induced B. pseudomallei genes were identified from the location of the insertions containing an active promoter activity. A proportion of the 138 genes identified in this way have been previously reported to be involved in metabolism and transport, virulence, or adaptation. Novel macrophage-induced B. pseudomallei genes were also identified. Quantitative reverse-transcription PCR analysis of 13 selected genes confirmed gene induction during macrophage infection. Deletion mutants of two macrophage-induced genes from this study were attenuated in Galleria mellonella larvae, suggesting roles in virulence. B. pseudomallei genes activated during macrophage infection may contribute to intracellular life and pathogenesis and merit further investigation toward control strategies for melioidosis.
Collapse
Affiliation(s)
- Siroj Jitprasutwit
- Department of Immunology, Faculty of Medicine Siriraj Hospital, Mahidol University, Bangkok, Thailand
| | - Niramol Jitprasutwit
- Department of Immunology, Faculty of Medicine Siriraj Hospital, Mahidol University, Bangkok, Thailand
| | | | - Nattawat Onlamoon
- Siriraj Research Group in Immunobiology and Therapeutic Sciences, Faculty of Medicine Siriraj Hospital, Mahidol University, Bangkok, Thailand
| | - Patoo Withatanung
- Department of Immunology, Faculty of Medicine Siriraj Hospital, Mahidol University, Bangkok, Thailand
| | - Veerachat Muangsombut
- Department of Immunology, Faculty of Medicine Siriraj Hospital, Mahidol University, Bangkok, Thailand
| | | | - Joanne M. Stevens
- The Roslin Institute, The Royal (Dick) School of Veterinary Studies, University of Edinburgh, Edinburgh, United Kingdom
| | - Catherine Ong
- Defence Medical and Environmental Research Institute, DSO National Laboratories, Singapore, Singapore
| | - Mark P. Stevens
- The Roslin Institute, The Royal (Dick) School of Veterinary Studies, University of Edinburgh, Edinburgh, United Kingdom
| | | | - Sunee Korbsrisate
- Department of Immunology, Faculty of Medicine Siriraj Hospital, Mahidol University, Bangkok, Thailand
| |
Collapse
|
17
|
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.
Collapse
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
| |
Collapse
|
18
|
Aschenbroich SA, Lafontaine ER, Lopez MC, Baker HV, Hogan RJ. Transcriptome analysis of human monocytic cells infected with Burkholderia species and exploration of pentraxin-3 as part of the innate immune response against the organisms. BMC Med Genomics 2019; 12:127. [PMID: 31492148 PMCID: PMC6729079 DOI: 10.1186/s12920-019-0575-7] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/07/2019] [Accepted: 08/29/2019] [Indexed: 01/13/2023] Open
Abstract
Background Burkholderia mallei (Bm) is a facultative intracellular bacterial pathogen causing highly-fatal glanders in solipeds and humans. The ability of Bm to thrive intracellularly is thought to be related to exploitation of host immune response-related genes and pathways. Relatively little is known of the molecular strategies employed by this pathogen to modulate these pathways and evade intracellular killing. This manuscript seeks to fill gaps in the understanding of the interface between Bm and innate immunity by examining gene expression changes during infection of host monocytes. Methods The transcriptome of Bm-infected human Mono Mac-6 (MM6) monocytes was profiled on Affymetrix Human Transcriptome GeneChips 2.0. Gene expression changes in Bm-infected monocytes were compared to those of Burkholderia thailandensis (Bt)-infected monocytes and to uninfected monocytes. The resulting dataset was normalized using Robust Multichip Average and subjected to statistical analyses employing a univariate F test with a random variance model. Differentially expressed genes significant at p < 0.001 were subjected to leave-one-out cross-validation studies and 1st and 3rd nearest neighbor prediction model. Significant probe sets were used to populate human pathways in Ingenuity Pathway Analysis, with statistical significance determined by Fisher’s exact test or z-score. Results The Pattern Recognition Receptor (PRR) pathway was represented among significantly enriched immune response-related human canonical pathways, with evidence of upregulation across both infections. Among members of this pathway, pentraxin-3 was significantly upregulated by Bm- or Bt-infected monocytes. Pentraxin-3 (PTX3) was demonstrated to bind to both Bt and Burkholderia pseudomallei (Bp), but not Bm. Subsequent assays did not identify a role for PTX3 in potentiating complement-mediated lysis of Bt or in enhancing phagocytosis or replication of Bt in human monocytes. Conclusion We report on the novel binding of PTX3 to Bt and Bp, with lack of interaction with Bm, suggesting that a possible evasive mechanism by Bm warrants further exploration. We determined that (1) PTX3 may not play a role in activating the lytic pathway of complement in different bacterial species and that (2) the opsonophagocytic properties of PTX3 should be investigated in different primary or immortalized cell lines representing host phagocytes, given lack of binding of PTX3 to MM6 monocytes.
Collapse
Affiliation(s)
- Sophie A Aschenbroich
- Department of Pathobiological Sciences, School of Veterinary Medicine, University of Wisconsin-Madison, 2015 Linden Drive, Madison, WI, 53706, USA
| | - Eric R Lafontaine
- Department of Infectious Diseases, College of Veterinary Medicine, University of Georgia, 501 D.W. Brooks Drive, Athens, GA, 30602, USA
| | - Maria Cecilia Lopez
- Department of Molecular Genetics and Microbiology, College of Medicine, University of Florida, 2015 SW 16th Ave, Gainesville, FL, 32608, USA
| | - Henry V Baker
- Department of Molecular Genetics and Microbiology, College of Medicine, University of Florida, 2015 SW 16th Ave, Gainesville, FL, 32608, USA
| | - Robert J Hogan
- Department of Infectious Diseases, College of Veterinary Medicine, University of Georgia, 501 D.W. Brooks Drive, Athens, GA, 30602, USA. .,Department of Veterinary Biosciences and Diagnostic Imaging, College of Veterinary Medicine, University of Georgia, 501 D.W. Brooks Drive, Athens, GA, 30602, USA.
| |
Collapse
|
19
|
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.
Collapse
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
| |
Collapse
|
20
|
Zimmerman SM, Long ME, Dyke JS, Jelesijevic TP, Michel F, Lafontaine ER, Hogan RJ. Use of Immunohistochemistry to Demonstrate In Vivo Expression of the Burkholderia mallei Virulence Factor BpaB During Experimental Glanders. Vet Pathol 2017; 55:258-267. [PMID: 29145795 DOI: 10.1177/0300985817736113] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/31/2022]
Abstract
Burkholderia mallei causes the highly contagious and debilitating zoonosis glanders, which infects via inhalation or percutaneous inoculation and often culminates in life-threatening pneumonia and sepsis. In humans, glanders is difficult to diagnose and requires prolonged antibiotic therapy with low success rates. No vaccine exists to protect against B. mallei, and there is concern regarding its use as a bioweapon. The authors previously identified the protein BpaB as a potential target for devising therapies due to its role in adherence to host cells and the formation of biofilms in vitro and its contribution to pathogenicity in a mouse model of glanders. In the present study, the authors developed an immunostaining approach to probe tissues of experimentally infected animals and demonstrated that BpaB is produced exclusively in vivo by wild-type B. mallei in target organs from mice and marmosets. They detected the expression of BpaB by B. mallei both extracellularly and within macrophages, neutrophils, and epithelial cells in respiratory tissues (7/10 marmoset; 2/2 mouse). The authors also noted the intracellular expression of BpaB by B. mallei in macrophages in the regional lymph nodes of mice (2/2 tissues) and MALT of marmosets (4/5 tissues). It is interesting that B. mallei bacteria infecting distal organs did not express BpaB (2/2 mice; 3/3 marmosets), suggesting that the protein is not necessary for bacterial fitness in these anatomic locations. These findings underscore the value of BpaB as a target for developing medical countermeasures and provide insight into its role in pathogenesis.
Collapse
Affiliation(s)
- Shawn M Zimmerman
- 1 Department of Infectious Diseases, University of Georgia College of Veterinary Medicine, Athens, GA, USA
| | - Mackenzie E Long
- 2 Veterinary Teaching Hospital, University of Georgia College of Veterinary Medicine, Athens, GA, USA
| | - Jeremy S Dyke
- 1 Department of Infectious Diseases, University of Georgia College of Veterinary Medicine, Athens, GA, USA
| | - Tomislav P Jelesijevic
- 1 Department of Infectious Diseases, University of Georgia College of Veterinary Medicine, Athens, GA, USA
| | - Frank Michel
- 3 Department of Veterinary Biosciences and Diagnostic Imaging, University of Georgia College of Veterinary Medicine, Athens, GA, USA
| | - Eric R Lafontaine
- 1 Department of Infectious Diseases, University of Georgia College of Veterinary Medicine, Athens, GA, USA
| | - Robert J Hogan
- 1 Department of Infectious Diseases, University of Georgia College of Veterinary Medicine, Athens, GA, USA.,3 Department of Veterinary Biosciences and Diagnostic Imaging, University of Georgia College of Veterinary Medicine, Athens, GA, USA
| |
Collapse
|
21
|
Mangalea MR, Borlee GI, Borlee BR. The Current Status of Extracellular Polymeric Substances Produced by Burkholderia pseudomallei. CURRENT TROPICAL MEDICINE REPORTS 2017. [DOI: 10.1007/s40475-017-0118-2] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/19/2022]
|
22
|
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.
Collapse
|
23
|
Willcocks SJ, Denman CC, Atkins HS, Wren BW. Intracellular replication of the well-armed pathogen Burkholderia pseudomallei. Curr Opin Microbiol 2016; 29:94-103. [DOI: 10.1016/j.mib.2015.11.007] [Citation(s) in RCA: 40] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/10/2015] [Revised: 11/27/2015] [Accepted: 11/30/2015] [Indexed: 12/31/2022]
|
24
|
David J, Bell RE, Clark GC. Mechanisms of Disease: Host-Pathogen Interactions between Burkholderia Species and Lung Epithelial Cells. Front Cell Infect Microbiol 2015; 5:80. [PMID: 26636042 PMCID: PMC4649042 DOI: 10.3389/fcimb.2015.00080] [Citation(s) in RCA: 23] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/11/2015] [Accepted: 10/30/2015] [Indexed: 11/17/2022] Open
Abstract
Members of the Burkholderia species can cause a range of severe, often fatal, respiratory diseases. A variety of in vitro models of infection have been developed in an attempt to elucidate the mechanism by which Burkholderia spp. gain entry to and interact with the body. The majority of studies have tended to focus on the interaction of bacteria with phagocytic cells with a paucity of information available with regard to the lung epithelium. However, the lung epithelium is becoming more widely recognized as an important player in innate immunity and the early response to infections. Here we review the complex relationship between Burkholderia species and epithelial cells with an emphasis on the most pathogenic species, Burkholderia pseudomallei and Burkholderia mallei. The current gaps in knowledge in our understanding are highlighted along with the epithelial host-pathogen interactions that offer potential opportunities for therapeutic intervention.
Collapse
Affiliation(s)
- Jonathan David
- Microbiology, Biomedical Sciences, Defence Science and Technology Laboratory Salisbury, UK
| | - Rachel E Bell
- Microbiology, Biomedical Sciences, Defence Science and Technology Laboratory Salisbury, UK ; Division of Immunology, Infection and Inflammatory Disease, Centre for Molecular and Cellular Biology of Inflammation, King's College London London, UK
| | - Graeme C Clark
- Microbiology, Biomedical Sciences, Defence Science and Technology Laboratory Salisbury, UK
| |
Collapse
|
25
|
Zimmerman SM, Michel F, Hogan RJ, Lafontaine ER. The Autotransporter BpaB Contributes to the Virulence of Burkholderia mallei in an Aerosol Model of Infection. PLoS One 2015; 10:e0126437. [PMID: 25993100 PMCID: PMC4438868 DOI: 10.1371/journal.pone.0126437] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/03/2015] [Accepted: 04/02/2015] [Indexed: 02/06/2023] Open
Abstract
Burkholderia mallei is a highly pathogenic bacterium that causes the zoonosis glanders. Previous studies indicated that the genome of the organism contains eight genes specifying autotransporter proteins, which are important virulence factors of Gram-negative bacteria. In the present study, we report the characterization of one of these autotransporters, BpaB. Database searches identified the bpaB gene in ten B. mallei isolates and the predicted proteins were 99-100% identical. Comparative sequence analyses indicate that the gene product is a trimeric autotransporter of 1,090 amino acids with a predicted molecular weight of 105-kDa. Consistent with this finding, we discovered that recombinant bacteria expressing bpaB produce a protein of ≥300-kDa on their surface that is reactive with a BpaB-specific monoclonal antibody. Analysis of sera from mice infected with B. mallei indicated that animals produce antibodies against BpaB during the course of disease, thus establishing production of the autotransporter in vivo. To gain insight on its role in virulence, we inactivated the bpaB gene of B. mallei strain ATCC 23344 and determined the median lethal dose of the mutant in a mouse model of aerosol infection. These experiments revealed that the bpaB mutation attenuates virulence 8-14 fold. Using a crystal violet-based assay, we also discovered that constitutive production of BpaB on the surface of B. mallei promotes biofilm formation. To our knowledge, this is the first report of a biofilm factor for this organism.
Collapse
Affiliation(s)
- Shawn M. Zimmerman
- Department of Infectious Diseases, University of Georgia College of Veterinary Medicine, Athens, Georgia, United States of America
| | - Frank Michel
- Department of Veterinary Biosciences and Diagnostic Imaging, University of Georgia College of Veterinary Medicine, Athens, GA, United States of America
| | - Robert J. Hogan
- Department of Infectious Diseases, University of Georgia College of Veterinary Medicine, Athens, Georgia, United States of America
- Department of Veterinary Biosciences and Diagnostic Imaging, University of Georgia College of Veterinary Medicine, Athens, GA, United States of America
| | - Eric R. Lafontaine
- Department of Infectious Diseases, University of Georgia College of Veterinary Medicine, Athens, Georgia, United States of America
- * E-mail:
| |
Collapse
|
26
|
Adler NRL, Stevens MP, Dean RE, Saint RJ, Pankhania D, Prior JL, Atkins TP, Kessler B, Nithichanon A, Lertmemongkolchai G, Galyov EE. Systematic mutagenesis of genes encoding predicted autotransported proteins of Burkholderia pseudomallei identifies factors mediating virulence in mice, net intracellular replication and a novel protein conferring serum resistance. PLoS One 2015; 10:e0121271. [PMID: 25830295 PMCID: PMC4382181 DOI: 10.1371/journal.pone.0121271] [Citation(s) in RCA: 16] [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: 09/19/2014] [Accepted: 01/29/2015] [Indexed: 01/12/2023] Open
Abstract
Burkholderia pseudomallei is the causative agent of the severe tropical disease melioidosis, which commonly presents as sepsis. The B. pseudomallei K96243 genome encodes eleven predicted autotransporters, a diverse family of secreted and outer membrane proteins often associated with virulence. In a systematic study of these autotransporters, we constructed insertion mutants in each gene predicted to encode an autotransporter and assessed them for three pathogenesis-associated phenotypes: virulence in the BALB/c intra-peritoneal mouse melioidosis model, net intracellular replication in J774.2 murine macrophage-like cells and survival in 45% (v/v) normal human serum. From the complete repertoire of eleven autotransporter mutants, we identified eight mutants which exhibited an increase in median lethal dose of 1 to 2-log10 compared to the isogenic parent strain (bcaA, boaA, boaB, bpaA, bpaC, bpaE, bpaF and bimA). Four mutants, all demonstrating attenuation for virulence, exhibited reduced net intracellular replication in J774.2 macrophage-like cells (bimA, boaB, bpaC and bpaE). A single mutant (bpaC) was identified that exhibited significantly reduced serum survival compared to wild-type. The bpaC mutant, which demonstrated attenuation for virulence and net intracellular replication, was sensitive to complement-mediated killing via the classical and/or lectin pathway. Serum resistance was rescued by in trans complementation. Subsequently, we expressed recombinant proteins of the passenger domain of four predicted autotransporters representing each of the phenotypic groups identified: those attenuated for virulence (BcaA), those attenuated for virulence and net intracellular replication (BpaE), the BpaC mutant with defects in virulence, net intracellular replication and serum resistance and those displaying wild-type phenotypes (BatA). Only BcaA and BpaE elicited a strong IFN-γ response in a restimulation assay using whole blood from seropositive donors and were recognised by seropositive human sera from the endemic area. To conclude, several predicted autotransporters contribute to B. pseudomallei virulence and BpaC may do so by conferring resistance against complement-mediated killing.
Collapse
Affiliation(s)
- Natalie R. Lazar Adler
- Department of Infection, Immunity and Inflammation, University of Leicester, Leicester, United Kingdom
| | - Mark P. Stevens
- The Roslin Institute and Royal (Dick) School of Veterinary Studies, University of Edinburgh, Easter Bush, United Kingdom
| | - Rachel E. Dean
- Biomedical Sciences, Defence Science and Technology Laboratory, Porton Down, United Kingdom
| | - Richard J. Saint
- Biomedical Sciences, Defence Science and Technology Laboratory, Porton Down, United Kingdom
| | - Depesh Pankhania
- Department of Infection, Immunity and Inflammation, University of Leicester, Leicester, United Kingdom
| | - Joann L. Prior
- Biomedical Sciences, Defence Science and Technology Laboratory, Porton Down, United Kingdom
| | - Timothy P. Atkins
- Biomedical Sciences, Defence Science and Technology Laboratory, Porton Down, United Kingdom
- School of Biosciences, Geoffrey Pope Building, University of Exeter, Exeter, United Kingdom
| | - Bianca Kessler
- The Centre for Research and Development of Medical Diagnostic Laboratories (CMDL), Faculty of Associated Medical Sciences, Khon Kaen University, Khon Kaen, Thailand
| | - Arnone Nithichanon
- The Centre for Research and Development of Medical Diagnostic Laboratories (CMDL), Faculty of Associated Medical Sciences, Khon Kaen University, Khon Kaen, Thailand
| | - Ganjana Lertmemongkolchai
- The Centre for Research and Development of Medical Diagnostic Laboratories (CMDL), Faculty of Associated Medical Sciences, Khon Kaen University, Khon Kaen, Thailand
| | - Edouard E. Galyov
- Department of Infection, Immunity and Inflammation, University of Leicester, Leicester, United Kingdom
- * E-mail:
| |
Collapse
|
27
|
Stone JK, DeShazer D, Brett PJ, Burtnick MN. Melioidosis: molecular aspects of pathogenesis. Expert Rev Anti Infect Ther 2014; 12:1487-99. [PMID: 25312349 DOI: 10.1586/14787210.2014.970634] [Citation(s) in RCA: 49] [Impact Index Per Article: 4.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/18/2022]
Abstract
Burkholderia pseudomallei is a gram-negative bacterium that causes melioidosis, a multifaceted disease that is highly endemic in southeast Asia and northern Australia. This facultative intracellular pathogen possesses a large genome that encodes a wide array of virulence factors that promote survival in vivo by manipulating host cell processes and disarming elements of the host immune system. Antigens and systems that play key roles in B. pseudomallei virulence include capsular polysaccharide, lipopolysaccharide, adhesins, specialized secretion systems, actin-based motility and various secreted factors. This review provides an overview of the current and steadily expanding knowledge regarding the molecular mechanisms used by this organism to survive within a host and their contribution to the pathogenesis of melioidosis.
Collapse
Affiliation(s)
- Joshua K Stone
- Department of Microbiology and Immunology, University of South Alabama, 610 Clinic Drive, Mobile, AL 36688, USA
| | | | | | | |
Collapse
|
28
|
Molecular characterization of putative virulence determinants in Burkholderia pseudomallei. ScientificWorldJournal 2014; 2014:590803. [PMID: 25215325 PMCID: PMC4158159 DOI: 10.1155/2014/590803] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/24/2014] [Accepted: 07/09/2014] [Indexed: 11/17/2022] Open
Abstract
The Gram-negative saprophyte Burkholderia pseudomallei is the causative agent of melioidosis, an infectious disease which is endemic in Southeast Asia and northern Australia. This bacterium possesses many virulence factors which are thought to contribute to its survival and pathogenicity. Using a virulent clinical isolate of B. pseudomallei and an attenuated strain of the same B. pseudomallei isolate, 6 genes BPSL2033, BP1026B_I2784, BP1026B_I2780, BURPS1106A_A0094, BURPS1106A_1131, and BURPS1710A_1419 were identified earlier by PCR-based subtractive hybridization. These genes were extensively characterized at the molecular level, together with an additional gene BPSL3147 that had been identified by other investigators. Through a reverse genetic approach, single-gene knockout mutants were successfully constructed by using site-specific insertion mutagenesis and were confirmed by PCR. BPSL2033::Km and BURPS1710A_1419::Km mutants showed reduced rates of survival inside macrophage RAW 264.7 cells and also low levels of virulence in the nematode infection model. BPSL2033::Km demonstrated weak statistical significance (P = 0.049) at 8 hours after infection in macrophage infection study but this was not seen in BURPS1710A_1419::Km. Nevertheless, complemented strains of both genes were able to partially restore the gene defects in both in vitro and in vivo studies, thus suggesting that they individually play a minor role in the virulence of B. pseudomallei.
Collapse
|
29
|
Lafontaine ER, Balder R, Michel F, Hogan RJ. Characterization of an autotransporter adhesin protein shared by Burkholderia mallei and Burkholderia pseudomallei. BMC Microbiol 2014; 14:92. [PMID: 24731253 PMCID: PMC4021183 DOI: 10.1186/1471-2180-14-92] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/31/2013] [Accepted: 04/08/2014] [Indexed: 12/21/2022] Open
Abstract
Background Autotransporters form a large family of outer membrane proteins specifying diverse biological traits of Gram-negative bacteria. In this study, we report the identification and characterization of a novel autotransporter gene product of Burkholderia mallei (locus tag BMA1027 in strain ATCC 23344). Results Database searches identified the gene in at least seven B. mallei isolates and the encoded proteins were found to be 84% identical. Inactivation of the gene encoding the autotransporter in the genome of strain ATCC 23344 substantially reduces adherence to monolayers of HEp-2 laryngeal cells and A549 type II pneumocytes, as well as to cultures of normal human bronchial epithelium (NHBE). Consistent with these findings, expression of the autotransporter on the surface of recombinant E. coli bacteria increases adherence to these cell types by 5–7 fold. The gene specifying the autotransporter was identified in the genome of 29 B. pseudomallei isolates and disruption of the gene in strain DD503 reduced adherence to NHBE cultures by 61%. Unlike B. mallei, the mutation did not impair binding of B. pseudomallei to A549 or HEp-2 cells. Analysis of sera from mice infected via the aerosol route with B. mallei and B. pseudomallei revealed that animals inoculated with as few as 10 organisms produce antibodies against the autotransporter, therefore indicating expression in vivo. Conclusions Our data demonstrate that we have identified an autotransporter protein common to the pathogenic species B. mallei and B. pseudomallei which mediates adherence to respiratory epithelial cells and is expressed in vivo during the course of aerosol infection.
Collapse
Affiliation(s)
- Eric R Lafontaine
- Department of Infectious Diseases, University of Georgia College of Veterinary Medicine, 30602 Athens, GA, USA.
| | | | | | | |
Collapse
|
30
|
Stubben CJ, Challacombe JF. Mining locus tags in PubMed Central to improve microbial gene annotation. BMC Bioinformatics 2014; 15:43. [PMID: 24499370 PMCID: PMC3937057 DOI: 10.1186/1471-2105-15-43] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/06/2013] [Accepted: 01/18/2014] [Indexed: 11/10/2022] Open
Abstract
BACKGROUND The scientific literature contains millions of microbial gene identifiers within the full text and tables, but these annotations rarely get incorporated into public sequence databases. We propose to utilize the Open Access (OA) subset of PubMed Central (PMC) as a gene annotation database and have developed an R package called pmcXML to automatically mine and extract locus tags from full text, tables and supplements. RESULTS We mined locus tags from 1835 OA publications in ten microbial genomes and extracted tags mentioned in 30,891 sentences in main text and 20,489 rows in tables. We identified locus tag pairs marking the start and end of a region such as an operon or genomic island and expanded these ranges to add another 13,043 tags. We also searched for locus tags in supplementary tables and publications outside the OA subset in Burkholderia pseudomallei K96243 for comparison. There were 168 publications containing 48,470 locus tags and 83% of mentions were from supplementary materials and 9% from publications outside the OA subset. CONCLUSIONS B. pseudomallei locus tags within the full text and tables of OA publications represent only a small fraction of the total mentions in the literature. For microbial genomes with very few functionally characterized proteins, the locus tags mentioned in supplementary tables and within ranges like genomic islands contain the majority of locus tags. Significantly, the functions in the R package provide access to additional resources in the OA subset that are not currently indexed or returned by searching PMC.
Collapse
Affiliation(s)
- Chris J Stubben
- Bioscience Division, Los Alamos National Laboratory, Los Alamos, NM, USA
| | - Jean F Challacombe
- Bioscience Division, Los Alamos National Laboratory, Los Alamos, NM, USA
| |
Collapse
|
31
|
Lazar Adler NR, Dean RE, Saint RJ, Stevens MP, Prior JL, Atkins TP, Galyov EE. Identification of a predicted trimeric autotransporter adhesin required for biofilm formation of Burkholderia pseudomallei. PLoS One 2013; 8:e79461. [PMID: 24223950 PMCID: PMC3818227 DOI: 10.1371/journal.pone.0079461] [Citation(s) in RCA: 22] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/07/2013] [Accepted: 09/23/2013] [Indexed: 01/25/2023] Open
Abstract
The autotransporters are a large and diverse family of bacterial secreted and outer membrane proteins, which are present in many Gram-negative bacterial pathogens and play a role in numerous environmental and virulence-associated interactions. As part of a larger systematic study on the autotransporters of Burkholderia pseudomallei, the causative agent of the severe tropical disease melioidosis, we have constructed an insertion mutant in the bpss1439 gene encoding an unstudied predicted trimeric autotransporter adhesin. The bpss1439 mutant demonstrated a significant reduction in biofilm formation at 48 hours in comparison to its parent 10276 wild-type strain. This phenotype was complemented to wild-type levels by the introduction of a full-length copy of the bpss1439 gene in trans. Examination of the wild-type and bpss1439 mutant strains under biofilm-inducing conditions by microscopy after 48 hours confirmed that the bpss1439 mutant produced less biofilm compared to wild-type. Additionally, it was observed that this phenotype was due to low levels of bacterial adhesion to the abiotic surface as well as reduced microcolony formation. In a murine melioidosis model, the bpss1439 mutant strain demonstrated a moderate attenuation for virulence compared to the wild-type strain. This attenuation was abrogated by in trans complementation, suggesting that bpss1439 plays a subtle role in the pathogenesis of B. pseudomallei. Taken together, these studies indicate that BPSS1439 is a novel predicted autotransporter involved in biofilm formation of B. pseudomallei; hence, this factor was named BbfA, Burkholderia biofilm factor A.
Collapse
Affiliation(s)
- Natalie R. Lazar Adler
- Department of Infection, Immunity and Inflammation, University of Leicester, Leicester, United Kingdom
| | - Rachel E. Dean
- Biomedical Sciences, Defence Science and Technology Laboratory, Porton Down, United Kingdom
| | - Richard J. Saint
- Biomedical Sciences, Defence Science and Technology Laboratory, Porton Down, United Kingdom
| | - Mark P. Stevens
- The Roslin Institute and Royal (Dick) School of Veterinary Studies, University of Edinburgh, Easter Bush, United Kingdom
| | - Joann L. Prior
- Biomedical Sciences, Defence Science and Technology Laboratory, Porton Down, United Kingdom
| | - Timothy P. Atkins
- Biomedical Sciences, Defence Science and Technology Laboratory, Porton Down, United Kingdom
- School of Biosciences, Geoffrey Pope Building, University of Exeter, Exeter, United Kingdom
| | - Edouard E. Galyov
- Department of Infection, Immunity and Inflammation, University of Leicester, Leicester, United Kingdom
- * E-mail:
| |
Collapse
|
32
|
Lafontaine ER, Zimmerman SM, Shaffer TL, Michel F, Gao X, Hogan RJ. Use of a safe, reproducible, and rapid aerosol delivery method to study infection by Burkholderia pseudomallei and Burkholderia mallei in mice. PLoS One 2013; 8:e76804. [PMID: 24098563 PMCID: PMC3788738 DOI: 10.1371/journal.pone.0076804] [Citation(s) in RCA: 26] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/26/2013] [Accepted: 08/26/2013] [Indexed: 11/24/2022] Open
Abstract
Burkholderia pseudomallei, the etiologic agent of melioidosis, is a saprophytic bacterium readily isolated from wet soils of countries bordering the equator. Burkholderia mallei is a host-adapted clone of B. pseudomallei that does not persist outside of its equine reservoir and causes the zoonosis glanders, which is endemic in Asia, Africa, the Middle East and South America. Infection by these organisms typically occurs via percutaneous inoculation or inhalation of aerosols, and the most common manifestation is severe pneumonia leading to fatal bacteremia. Glanders and melioidosis are difficult to diagnose and require prolonged antibiotic therapy with low success rates. There are no vaccines available to protect against either Burkholderia species, and there is concern regarding their use as biological warfare agents given that B. mallei has previously been utilized in this manner. Hence, experiments were performed to establish a mouse model of aerosol infection to study the organisms and develop countermeasures. Using a hand-held aerosolizer, BALB/c mice were inoculated intratracheally with strains B. pseudomallei 1026b and B. mallei ATCC23344 and growth of the agents in the lungs, as well as dissemination to the spleen, were examined. Mice infected with 102, 103 and 104 organisms were unable to control growth of B. mallei in the lungs and bacteria rapidly disseminated to the spleen. Though similar results were observed in mice inoculated with 103 and 104B. pseudomallei cells, animals infected with 102 organisms controlled bacterial replication in the lungs, dissemination to the spleen, and the extent of bacteremia. Analysis of sera from mice surviving acute infection revealed that animals produced antibodies against antigens known to be targets of the immune response in humans. Taken together, these data show that small volume aerosol inoculation of mice results in acute disease, dose-dependent chronic infection, and immune responses that correlate with those seen in human infections.
Collapse
Affiliation(s)
- Eric R. Lafontaine
- Department of Infectious Diseases, University of Georgia, Athens, Georgia, United States of America
| | - Shawn M. Zimmerman
- Department of Infectious Diseases, University of Georgia, Athens, Georgia, United States of America
| | - Teresa L. Shaffer
- Department of Microbiology, University of Georgia, Athens, Georgia, United States of America
| | - Frank Michel
- Department of Veterinary Biosciences and Diagnostic Imaging, University of Georgia, Athens, Georgia, United States of America
| | - Xiudan Gao
- Department of Veterinary Biosciences and Diagnostic Imaging, University of Georgia, Athens, Georgia, United States of America
| | - Robert J. Hogan
- Department of Veterinary Biosciences and Diagnostic Imaging, University of Georgia, Athens, Georgia, United States of America
- * E-mail:
| |
Collapse
|
33
|
Functional characterization of Burkholderia pseudomallei trimeric autotransporters. Infect Immun 2013; 81:2788-99. [PMID: 23716608 DOI: 10.1128/iai.00526-13] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
Burkholderia pseudomallei is a tier 1 select agent and the causative agent of melioidosis, a severe and often fatal disease with symptoms ranging from acute pneumonia and septic shock to a chronic infection characterized by abscess formation in the lungs, liver, and spleen. Autotransporters (ATs) are exoproteins belonging to the type V secretion system family, with many playing roles in pathogenesis. The genome of B. pseudomallei strain 1026b encodes nine putative trimeric AT proteins, of which only four have been described. Using a bioinformatic approach, we annotated putative domains within each trimeric AT protein, excluding the well-studied BimA protein, and found short repeated sequences unique to Burkholderia species, as well as an unexpectedly large proportion of ATs with extended signal peptide regions (ESPRs). To characterize the role of trimeric ATs in pathogenesis, we constructed disruption or deletion mutations in each of eight AT-encoding genes and evaluated the resulting strains for adherence to, invasion of, and plaque formation in A549 cells. The majority of the ATs (and/or the proteins encoded downstream) contributed to adherence to and efficient invasion of A549 cells. Using a BALB/c mouse model of infection, we determined the contributions of each AT to bacterial burdens in the lungs, liver, and spleen. At 48 h postinoculation, only one strain, Bp340::pDbpaC, demonstrated a defect in dissemination and/or survival in the liver, indicating that BpaC is required for wild-type virulence in this model.
Collapse
|
34
|
Denman CC, Brown AR. Mannitol promotes adherence of an outbreak strain of Burkholderia multivorans via an exopolysaccharide-independent mechanism that is associated with upregulation of newly identified fimbrial and afimbrial adhesins. MICROBIOLOGY-SGM 2013; 159:771-781. [PMID: 23378576 DOI: 10.1099/mic.0.064832-0] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/18/2022]
Abstract
Burkholderia multivorans, a member of the Burkholderia cepacia complex (Bcc), is an important pathogen of the cystic fibrosis (CF) lung. Mannitol, approved as an inhaled osmolyte therapy for use in CF patients, promotes exopolysaccharide (EPS) production by the Bcc. In the present study, we investigated the role of mannitol-induced EPS in the adherence of B. multivorans. We report that mannitol promoted adherence of two representative B. multivorans strains. However, whilst this enhanced adherence was largely EPS-dependent in an environmental isolate, it was EPS-independent within a CF outbreak strain, suggesting strain-to-strain variation in adhesins. Genome sequencing of the outbreak strain enabled the identification of two distinct loci encoding putative fimbrial and afimbrial adhesins. The putative fimbriae-encoding locus was found to be widely distributed amongst clinical and environmental B. multivorans. In contrast, the locus encoding the putative afimbrial adhesin (of the filamentous haemagglutinin family, FHA) was restricted to clinical isolates. Both loci contributed to biofilm formation and mucin adherence. Furthermore, we report that mannitol promoted expression of both loci, and that the locus encoding the putative FHA-family adhesin is a key determinant of the enhanced adherence observed following growth in mannitol. Our studies provide the first characterization, to our knowledge, of B. multivorans adhesins, and in so doing highlight the strain-dependent role of EPS in the Bcc and the difficulties in assigning phenotypic traits to Bcc EPS due to the wider response to mannitol. Our observations also highlight the need to monitor the microbiological effects of inhaled mannitol therapy in Bcc-infected CF patients.
Collapse
Affiliation(s)
- Carmen C Denman
- Biosciences, College of Life and Environmental Sciences, University of Exeter, Exeter EX4 4QD, UK
| | - Alan R Brown
- Biosciences, College of Life and Environmental Sciences, University of Exeter, Exeter EX4 4QD, UK
| |
Collapse
|
35
|
Lu R, Popov V, Patel J, Eaves-Pyles T. Burkholderia mallei and Burkholderia pseudomallei stimulate differential inflammatory responses from human alveolar type II cells (ATII) and macrophages. Front Cell Infect Microbiol 2012; 2:165. [PMID: 23293773 PMCID: PMC3531596 DOI: 10.3389/fcimb.2012.00165] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/03/2012] [Accepted: 12/07/2012] [Indexed: 01/11/2023] Open
Abstract
Alveolar type II pneumocytes (ATII) and alveolar macrophages (AM) play a crucial role in the lung's innate immune response. Burkholderia pseudomallei (BP) and Burkholderia mallei (BM) are facultative Gram-negative bacilli that cause melioidosis and glanders, respectively. The inhalation of these pathogens can cause lethal disease and death in humans. We sought to compare the pathogenesis of and host responses to BP and BM through contact with human primary ATII cells and monocytes-derived macrophages (MDM). We hypothesized that because BP and BM induce different disease outcomes, each pathogen would induce distinct, unique host immune responses from resident pulmonary cells. Our findings showed that BP adhered readily to ATII cells compared to BM. BP, but not BM, was rapidly internalized by macrophages where it replicated to high numbers. Further, BP-induced significantly higher levels of pro-inflammatory cytokine secretion from ATII cells (IL-6, IL-8) and macrophages (IL-6, TNFα) at 6 h post-infection compared to BM (p < 0.05). Interestingly, BM-induced the anti-inflammatory cytokine, IL-10, in ATII cells and macrophages at 6 h post-infection, with delayed induction of inflammatory cytokines at 24 h post-infection. Because BP is flagellated and produces LPS, we confirmed that it stimulated both Toll-like receptor (TLR) 4 and TLR5 via NF-κb activation while the non-flagellated BM stimulated only TLR4. These data show the differences in BP and BM pathogenicity in the lung when infecting human ATII cells and macrophages and demonstrate the ability of these pathogens to elicit distinct immune responses from resident lung cells which may open new targets for therapeutic intervention to fight against these pathogens.
Collapse
Affiliation(s)
- Richard Lu
- Department of Microbiology and Immunology, University of Texas Medical Branch Galveston, TX, USA
| | | | | | | |
Collapse
|
36
|
Allwood EM, Devenish RJ, Prescott M, Adler B, Boyce JD. Strategies for Intracellular Survival of Burkholderia pseudomallei. Front Microbiol 2011; 2:170. [PMID: 22007185 PMCID: PMC3159172 DOI: 10.3389/fmicb.2011.00170] [Citation(s) in RCA: 85] [Impact Index Per Article: 6.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/18/2011] [Accepted: 07/26/2011] [Indexed: 11/13/2022] Open
Abstract
Burkholderia pseudomallei is the causative agent of melioidosis, a disease with high mortality that is prevalent in tropical regions of the world. A key component of the pathogenesis of melioidosis is the ability of B. pseudomallei to enter, survive, and replicate within mammalian host cells. For non-phagocytic cells, bacterial adhesins have been identified both on the bacterial surface and associated with Type 4 pili. Cell invasion involves components of one or more of the three Type 3 Secretion System clusters, which also mediate, at least in part, the escape of bacteria from the endosome into the cytoplasm, where bacteria move by actin-based motility. The mechanism of actin-based motility is not clearly understood, but appears to differ from characterized mechanisms in other bacterial species. A small proportion of intracellular bacteria is targeted by host cell autophagy, involving direct recruitment of LC3 to endosomes rather than through uptake by canonical autophagosomes. However, the majority of bacterial cells are able to circumvent autophagy and other intracellular defense mechanisms such as the induction of inducible nitric oxide synthase, and then replicate in the cytoplasm and spread to adjacent cells via membrane fusion, resulting in the formation of multi-nucleated giant cells. A potential role for host cell ubiquitin in the autophagic response to bacterial infection has recently been proposed.
Collapse
|
37
|
Lazar Adler NR, Stevens JM, Stevens MP, Galyov EE. Autotransporters and Their Role in the Virulence of Burkholderia pseudomallei and Burkholderia mallei. Front Microbiol 2011; 2:151. [PMID: 21811486 PMCID: PMC3139927 DOI: 10.3389/fmicb.2011.00151] [Citation(s) in RCA: 24] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/28/2011] [Accepted: 06/28/2011] [Indexed: 11/19/2022] Open
Abstract
Burkholderia pseudomallei and Burkholderia mallei are closely related Gram-negative bacteria responsible for the infectious diseases melioidosis and glanders, respectively. Autotransporters (ATs) comprise a large and diverse family of secreted and outer membrane proteins that includes virulence-associated invasins, adhesins, proteases, and actin-nucleating factors. The B. pseudomallei K96243 genome contains 11 predicted ATs, eight of which share homologs in the B. mallei ATCC 23344 genome. This review distils key findings from in silico, in vitro, and in vivo studies on the ATs of B. pseudomallei and B. mallei. To date, the best characterized of the predicted ATs of B. pseudomallei and B. mallei is BimA, a predicted trimeric AT mediating actin-based motility which varies in sequence and mode of action between Burkholderia species. Of the remaining eight predicted B. pseudomallei trimeric autotransporters, five of which are also present in B. mallei, two (BoaA and BoaB), have been implicated in bacterial adhesion to epithelial cells. Several predicted Burkholderia ATs are recognized by human humoral and cell-mediated immunity, indicating that they are expressed during infection and may be useful for diagnosis and vaccine-mediated protection. Further studies on the mode of secretion and functions of Burkholderia ATs will facilitate the rational design of control strategies.
Collapse
Affiliation(s)
- Natalie R Lazar Adler
- Department of Infection, Immunity and Inflammation, University of Leicester Leicester, UK
| | | | | | | |
Collapse
|