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Selvam K, Najib MA, Khalid MF, Yunus MH, Wahab HA, Harun A, Zainulabid UA, Fadzli Mustaffa KM, Aziah I. Isolation and characterization of ssDNA aptamers against BipD antigen of Burkholderia pseudomallei. Anal Biochem 2024; 695:115655. [PMID: 39214325 DOI: 10.1016/j.ab.2024.115655] [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: 06/27/2024] [Revised: 08/19/2024] [Accepted: 08/27/2024] [Indexed: 09/04/2024]
Abstract
BACKGROUND Melioidosis is difficult to diagnose due to its wide range of clinical symptoms. The culture method is time-consuming and less sensitive, emphasizing the importance of rapid and accurate diagnostic tests for melioidosis. Burkholderia invasion protein D (BipD) of Burkholderia pseudomallei is a potential diagnostic biomarker. This study aimed to isolate and characterize single-stranded DNA aptamers that specifically target BipD. METHODS The recombinant BipD protein was produced, followed by isolation of BipD-specific aptamers using Systematic Evolution of Ligands by EXponential enrichment. The binding affinity and specificity of the selected aptamers were evaluated using Enzyme-Linked Oligonucleotide Assay. RESULTS The fifth SELEX cycle showed a notable enrichment of recombinant BipD protein-specific aptamers. Sequencing analysis identified two clusters with a total of seventeen distinct aptamers. AptBipD1, AptBipD13, and AptBipD50 were chosen based on their frequency. Among them, AptBipD1 exhibited the highest binding affinity with a Kd value of 1.0 μM for the recombinant BipD protein. Furthermore, AptBipD1 showed significant specificity for B. pseudomallei compared to other tested bacteria. CONCLUSION AptBipD1 is a promising candidate for further development of reliable, affordable, and efficient point-of-care diagnostic tests for melioidosis.
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Affiliation(s)
- Kasturi Selvam
- Institute for Research in Molecular Medicine (INFORMM), Universiti Sains Malaysia, Kubang Kerian, 16150, Kelantan, Malaysia
| | - Mohamad Ahmad Najib
- Institute for Research in Molecular Medicine (INFORMM), Universiti Sains Malaysia, Kubang Kerian, 16150, Kelantan, Malaysia
| | - Muhammad Fazli Khalid
- Institute for Research in Molecular Medicine (INFORMM), Universiti Sains Malaysia, Kubang Kerian, 16150, Kelantan, Malaysia
| | - Muhammad Hafiznur Yunus
- Institute for Research in Molecular Medicine (INFORMM), Universiti Sains Malaysia, Kubang Kerian, 16150, Kelantan, Malaysia
| | - Habibah A Wahab
- School of Pharmaceutical Sciences, Universiti Sains Malaysia, 11800, Pulau, Pinang, Malaysia
| | - Azian Harun
- Department of Medical Microbiology and Parasitology, School of Medical Sciences, Universiti Sains Malaysia, Kubang Kerian, 16150, Kelantan, Malaysia; Hospital Universiti Sains Malaysia, Kubang Kerian, 16150, Kelantan, Malaysia
| | - Ummu Afeera Zainulabid
- Department of Internal Medicine, Kulliyyah of Medicine, International Islamic University Malaysia, Kuantan, 25200, Pahang, Malaysia
| | - Khairul Mohd Fadzli Mustaffa
- Institute for Research in Molecular Medicine (INFORMM), Universiti Sains Malaysia, Kubang Kerian, 16150, Kelantan, Malaysia
| | - Ismail Aziah
- Institute for Research in Molecular Medicine (INFORMM), Universiti Sains Malaysia, Kubang Kerian, 16150, Kelantan, Malaysia.
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Lawal OU, Bryan N, Parreira VR, Anderson R, Chen Y, Precious M, Goodridge L. Phylogenomics of novel clones of Aeromonas veronii recovered from a freshwater lake reveals unique biosynthetic gene clusters. Microbiol Spectr 2024; 12:e0117124. [PMID: 39513706 PMCID: PMC11619367 DOI: 10.1128/spectrum.01171-24] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/11/2024] [Accepted: 09/23/2024] [Indexed: 11/15/2024] Open
Abstract
Aquatic ecosystems serve as crucial reservoirs for pathogens and antimicrobial resistance genes, thus presenting a significant global health risk. Here, we investigated the phylogenomics of Aeromonas veronii from Lake Wilcox in Ontario. Among the 11 bacterial isolates, nine were identified as A. veronii. Notably, 67% of A. veronii isolates were potential human pathogens. Considerable genetic diversity was noted among the A. veronii isolates, suggesting the lake as a reservoir for multiple human pathogenic strains. Comparison of the A. veronii sequenced with global A. veronii genomes highlighted significant genetic diversity and suggests widespread dissemination of strains. All the isolates carried chromosomal genes encoding resistance to β-lactams. Although virulence gene content differed between human and non-human pathogenic strains, type III secretion systems was associated with human pathogenic isolates. The assessment of AMR genes in global isolates showed that β-lactam and tetracycline resistance genes were predominant. Although the machine learning-based pangenome-wide association approach performed did not yield any source-based genes, some genes were enriched in a few isolates from different sources. The mrkABCDF operon that mediates biofilm formation and genes encoding resistance to colistin, chloramphenicol, trimethoprim, and tetracycline were enriched in animal products, whereas macrolide resistance genes and Inc plasmid-types were linked to the aquatic environment. Novel biosynthetic gene clusters were identified, suggesting that A. veronii with varying pathogenic potential could produce unique secondary metabolites. There is a need for continuous tracking of pathogens in aquatic ecosystems to contribute to our understanding of their evolutionary dynamics and the ecological roles of their genetic elements. IMPORTANCE Lakes and other aquatic ecosystems can harbor harmful bacteria that can make people sick and resist antibiotics, posing a significant global health risk. In this study, we investigated Aeromonas veronii, a Gram-negative bacteria found in Lake Wilcox in Ontario. We used various techniques, including whole-genome sequencing (WGS), to analyze the bacteria and found that many of the isolates had the potential to cause human disease. We also discovered significant genetic diversity among the isolates, indicating that the lake may be a reservoir for multiple human pathogenic strains. All isolates carried genes that confer resistance to antibiotics, and some virulence genes were associated with human pathogenic isolates. This study highlights the importance of monitoring aquatic ecosystems for harmful bacteria to better understand their evolution, potential for human pathogenicity, and the ecological roles of their genetic elements. This knowledge can inform strategies for preventing the spread of antibiotic-resistant bacteria and protecting public health.
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Affiliation(s)
- Opeyemi U. Lawal
- Canadian Research Institute for Food Safety (CRIFS), University of Guelph, Guelph, Ontario, Canada
| | - Noah Bryan
- Canadian Research Institute for Food Safety (CRIFS), University of Guelph, Guelph, Ontario, Canada
- Bayview Secondary School, Richmond Hill, Ontario, Canada
| | - Valeria R. Parreira
- Canadian Research Institute for Food Safety (CRIFS), University of Guelph, Guelph, Ontario, Canada
| | - Rebecca Anderson
- Canadian Research Institute for Food Safety (CRIFS), University of Guelph, Guelph, Ontario, Canada
| | - Yanhong Chen
- Canadian Research Institute for Food Safety (CRIFS), University of Guelph, Guelph, Ontario, Canada
| | - Melinda Precious
- Canadian Research Institute for Food Safety (CRIFS), University of Guelph, Guelph, Ontario, Canada
| | - Lawrence Goodridge
- Canadian Research Institute for Food Safety (CRIFS), University of Guelph, Guelph, Ontario, Canada
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Yan J, Yang B, Xue X, Li J, Li Y, Li A, Ding P, Cao B. Transcriptome Analysis Reveals the Effect of PdhR in Plesiomonas shigelloides. Int J Mol Sci 2023; 24:14473. [PMID: 37833920 PMCID: PMC10572922 DOI: 10.3390/ijms241914473] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/29/2023] [Revised: 09/19/2023] [Accepted: 09/21/2023] [Indexed: 10/15/2023] Open
Abstract
The pyruvate dehydrogenase complex regulator (PdhR) was originally identified as a repressor of the pdhR-aceEF-lpd operon, which encodes the pyruvate dehydrogenase complex (PDHc) and PdhR itself. According to previous reports, PdhR plays a regulatory role in the physiological and metabolic pathways of bacteria. At present, the function of PdhR in Plesiomonas shigelloides is still poorly understood. In this study, RNA sequencing (RNA-Seq) of the wild-type strain and the ΔpdhR mutant strains was performed for comparison to identify the PdhR-controlled pathways, revealing that PdhR regulates ~7.38% of the P. shigelloides transcriptome. We found that the deletion of pdhR resulted in the downregulation of practically all polar and lateral flagella genes in P. shigelloides; meanwhile, motility assay and transmission electron microscopy (TEM) confirmed that the ΔpdhR mutant was non-motile and lacked flagella. Moreover, the results of RNA-seq and quantitative Real-Time Polymerase Chain Reaction (qRT-PCR) showed that PdhR positively regulated the expression of the T3SS cluster, and the ΔpdhR mutant significantly reduced the ability of P. shigelloides to infect Caco-2 cells compared with the WT. Consistent with previous research, pyruvate-sensing PdhR directly binds to its promoter and inhibits pdhR-aceEF-lpd operon expression. In addition, we identified two additional downstream genes, metR and nuoA, that are directly negatively regulated by PdhR. Furthermore, we also demonstrated that ArcA was identified as being located upstream of pdhR and lpdA and directly negatively regulating their expression. Overall, we revealed the function and regulatory pathway of PdhR, which will allow for a more in-depth investigation into P. shigelloides pathogenicity as well as the complex regulatory network.
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Affiliation(s)
- Junxiang Yan
- TEDA Institute of Biological Sciences and Biotechnology, Nankai University, Tianjin 300457, China
- Key Laboratory of Molecular Microbiology and Technology of the Ministry of Education, Nankai University, Tianjin 300457, China
- Tianjin Key Laboratory of Microbial Functional Genomics, TEDA College, Nankai University, Tianjin 300457, China
| | - Bin Yang
- TEDA Institute of Biological Sciences and Biotechnology, Nankai University, Tianjin 300457, China
- Key Laboratory of Molecular Microbiology and Technology of the Ministry of Education, Nankai University, Tianjin 300457, China
- Tianjin Key Laboratory of Microbial Functional Genomics, TEDA College, Nankai University, Tianjin 300457, China
| | - Xinke Xue
- TEDA Institute of Biological Sciences and Biotechnology, Nankai University, Tianjin 300457, China
- Key Laboratory of Molecular Microbiology and Technology of the Ministry of Education, Nankai University, Tianjin 300457, China
- Tianjin Key Laboratory of Microbial Functional Genomics, TEDA College, Nankai University, Tianjin 300457, China
| | - Jinghao Li
- TEDA Institute of Biological Sciences and Biotechnology, Nankai University, Tianjin 300457, China
- Key Laboratory of Molecular Microbiology and Technology of the Ministry of Education, Nankai University, Tianjin 300457, China
- Tianjin Key Laboratory of Microbial Functional Genomics, TEDA College, Nankai University, Tianjin 300457, China
| | - Yuehua Li
- TEDA Institute of Biological Sciences and Biotechnology, Nankai University, Tianjin 300457, China
- Key Laboratory of Molecular Microbiology and Technology of the Ministry of Education, Nankai University, Tianjin 300457, China
- Tianjin Key Laboratory of Microbial Functional Genomics, TEDA College, Nankai University, Tianjin 300457, China
| | - Ang Li
- State Key Laboratory of Medicinal Chemical Biology, Nankai University, Tianjin 300353, China
- College of Pharmacy Laboratory of Molecular Drug Research, Nankai University, Tianjin 300353, China
| | - Peng Ding
- TEDA Institute of Biological Sciences and Biotechnology, Nankai University, Tianjin 300457, China
- Key Laboratory of Molecular Microbiology and Technology of the Ministry of Education, Nankai University, Tianjin 300457, China
- Tianjin Key Laboratory of Microbial Functional Genomics, TEDA College, Nankai University, Tianjin 300457, China
| | - Boyang Cao
- TEDA Institute of Biological Sciences and Biotechnology, Nankai University, Tianjin 300457, China
- Key Laboratory of Molecular Microbiology and Technology of the Ministry of Education, Nankai University, Tianjin 300457, China
- Tianjin Key Laboratory of Microbial Functional Genomics, TEDA College, Nankai University, Tianjin 300457, China
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Kaval KG, Chimalapati S, Siegel SD, Garcia N, Jaishankar J, Dalia AB, Orth K. Membrane-localized expression, production and assembly of Vibrio parahaemolyticus T3SS2 provides evidence for transertion. Nat Commun 2023; 14:1178. [PMID: 36859532 PMCID: PMC9977878 DOI: 10.1038/s41467-023-36762-z] [Citation(s) in RCA: 5] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/14/2022] [Accepted: 02/15/2023] [Indexed: 03/03/2023] Open
Abstract
It has been proposed that bacterial membrane proteins may be synthesized and inserted into the membrane by a process known as transertion, which involves membrane association of their encoding genes, followed by coupled transcription, translation and membrane insertion. Here, we provide evidence supporting that the pathogen Vibrio parahaemolyticus uses transertion to assemble its type III secretion system (T3SS2), to inject virulence factors into host cells. We propose a two-step transertion process where the membrane-bound co-component receptor (VtrA/VtrC) is first activated by bile acids, leading to membrane association and expression of its target gene, vtrB, located in the T3SS2 pathogenicity island. VtrB, the transmembrane transcriptional activator of T3SS2, then induces the localized expression and membrane assembly of the T3SS2 structural components and its effectors. We hypothesize that the proposed transertion process may be used by other enteric bacteria for efficient assembly of membrane-bound molecular complexes in response to extracellular signals.
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Affiliation(s)
- Karan Gautam Kaval
- Department of Molecular Biology, University of Texas Southwestern Medical Center, Dallas, TX, 75390, USA
- Howard Hughes Medical Institute, University of Texas Southwestern Medical Center, Dallas, TX, 75390, USA
| | | | - Sara D Siegel
- Biomanufacturing Training and Education Center, North Carolina State University, Raleigh, NC, 27606, USA
| | - Nalleli Garcia
- Department of Microbiology and Cell Science, University of Florida, Gainesville, FL, 32611, USA
| | - Jananee Jaishankar
- Department of Molecular Biology, University of Texas Southwestern Medical Center, Dallas, TX, 75390, USA
| | - Ankur B Dalia
- Department of Biology, Indiana University, Bloomington, IN, 47405, USA
| | - Kim Orth
- Department of Molecular Biology, University of Texas Southwestern Medical Center, Dallas, TX, 75390, USA.
- Howard Hughes Medical Institute, University of Texas Southwestern Medical Center, Dallas, TX, 75390, USA.
- Department of Biochemistry, University of Texas Southwestern Medical Center, Dallas, TX, 75390, USA.
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The Assembly of Flagella in Enteropathogenic Escherichia coli Requires the Presence of a Functional Type III Secretion System. Int J Mol Sci 2022; 23:ijms232213705. [PMID: 36430181 PMCID: PMC9694695 DOI: 10.3390/ijms232213705] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/21/2022] [Revised: 10/31/2022] [Accepted: 11/02/2022] [Indexed: 11/09/2022] Open
Abstract
In enteropathogenic Escherichia coli (EPEC), the production of flagella and the type III secretion system (T3SS) is activated in the presence of host cultured epithelial cells. The goal of this study was to investigate the relationship between expression of flagella and the T3SS. Mutants deficient in assembling T3SS basal and translocon components (ΔespA, ΔespB, ΔespD, ΔescC, ΔescN, and ΔescV), and in secreting effector molecules (ΔsepD and ΔsepL) were tested for flagella production under several growth conditions. The ΔespA mutant did not produce flagella in any condition tested, although fliC was transcribed. The remaining mutants produced different levels of flagella upon growth in LB or in the presence of cells but were significantly diminished in flagella production after growth in Dulbecco's minimal essential medium. We also investigated the role of virulence and global regulator genes in expression of flagella. The ΔqseB and ΔqseC mutants produced abundant flagella only when growing in LB and in the presence of HeLa cells, indicating that QseB and QseC act as negative regulators of fliC transcription. The ΔgrlR, ΔperA, Δler, Δhns, and Δfis mutants produced low levels of flagella, suggesting these regulators are activators of fliC expression. These data suggest that the presence of an intact T3SS is required for assembly of flagella highlighting the existence in EPEC of a cross-talk between these two virulence-associated T3SSs.
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A Highly Unstable and Elusive Plasmid That Encodes the Type III Secretion System Is Necessary for Full Virulence in the Marine Fish Pathogen Photobacterium damselae subsp. piscicida. Int J Mol Sci 2022; 23:ijms23094729. [PMID: 35563122 PMCID: PMC9105992 DOI: 10.3390/ijms23094729] [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] [Received: 04/08/2022] [Revised: 04/21/2022] [Accepted: 04/22/2022] [Indexed: 01/27/2023] Open
Abstract
The marine bacterium Photobacterium damselae subsp. piscicida (Pdp) causes photobacteriosis in fish and important financial losses in aquaculture, but knowledge of its virulence factors is still scarce. We here demonstrate that an unstable plasmid (pPHDPT3) that encodes a type III secretion system (T3SS) is highly prevalent in Pdp strains from different geographical origins and fish host species. We found that pPHDPT3 undergoes curing upon in vitro cultivation, and this instability constitutes a generalized feature of pPHDPT3-like plasmids in Pdp strains. pPHDPT3 markers were detected in tissues of naturally-infected moribund fish and in the Pdp colonies grown directly from the fish tissues but were undetectable in a fraction of the colonies produced upon the first passage of the primeval colonies on agar plates. Notably, cured strains exhibited a marked reduction in virulence for fish, demonstrating that pPHDPT3 is a major virulence factor of Pdp. The attempts to stabilize pPHDPT3 by insertion of antibiotic resistance markers by allelic exchange caused an even greater reduction in virulence. We hypothesize that the existence of a high pressure to shed pPHDPT3 plasmid in vitro caused the selection of clones with off-target mutations and gene rearrangements during the process of genetic modification. Collectively, these results show that pPHDPT3 constitutes a novel, hitherto unreported virulence factor of Pdp that shows a high instability in vitro and warn that the picture of Pdp virulence genes has been historically underestimated, since the loss of the T3SS and other plasmid-borne genes may have occurred systematically in laboratories for decades.
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