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Pedraza-Reyes M, Abundiz-Yañez K, Rangel-Mendoza A, Martínez LE, Barajas-Ornelas RC, Cuéllar-Cruz M, Leyva-Sánchez HC, Ayala-García VM, Valenzuela-García LI, Robleto EA. Bacillus subtilis stress-associated mutagenesis and developmental DNA repair. Microbiol Mol Biol Rev 2024; 88:e0015823. [PMID: 38551349 DOI: 10.1128/mmbr.00158-23] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 04/04/2024] Open
Abstract
SUMMARYThe metabolic conditions that prevail during bacterial growth have evolved with the faithful operation of repair systems that recognize and eliminate DNA lesions caused by intracellular and exogenous agents. This idea is supported by the low rate of spontaneous mutations (10-9) that occur in replicating cells, maintaining genome integrity. In contrast, when growth and/or replication cease, bacteria frequently process DNA lesions in an error-prone manner. DNA repairs provide cells with the tools needed for maintaining homeostasis during stressful conditions and depend on the developmental context in which repair events occur. Thus, different physiological scenarios can be anticipated. In nutritionally stressed bacteria, different components of the base excision repair pathway may process damaged DNA in an error-prone approach, promoting genetic variability. Interestingly, suppressing the mismatch repair machinery and activating specific DNA glycosylases promote stationary-phase mutations. Current evidence also suggests that in resting cells, coupling repair processes to actively transcribed genes may promote multiple genetic transactions that are advantageous for stressed cells. DNA repair during sporulation is of interest as a model to understand how transcriptional processes influence the formation of mutations in conditions where replication is halted. Current reports indicate that transcriptional coupling repair-dependent and -independent processes operate in differentiating cells to process spontaneous and induced DNA damage and that error-prone synthesis of DNA is involved in these events. These and other noncanonical ways of DNA repair that contribute to mutagenesis, survival, and evolution are reviewed in this manuscript.
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Affiliation(s)
- Mario Pedraza-Reyes
- Department of Biology, Division of Natural and Exact Sciences, University of Guanajuato, Guanajuato, Mexico
| | - Karen Abundiz-Yañez
- Department of Biology, Division of Natural and Exact Sciences, University of Guanajuato, Guanajuato, Mexico
| | - Alejandra Rangel-Mendoza
- Department of Biology, Division of Natural and Exact Sciences, University of Guanajuato, Guanajuato, Mexico
| | - Lissett E Martínez
- Department of Biology, Division of Natural and Exact Sciences, University of Guanajuato, Guanajuato, Mexico
| | - Rocío C Barajas-Ornelas
- Department of Biology, Division of Natural and Exact Sciences, University of Guanajuato, Guanajuato, Mexico
| | - Mayra Cuéllar-Cruz
- Department of Biology, Division of Natural and Exact Sciences, University of Guanajuato, Guanajuato, Mexico
| | | | | | - Luz I Valenzuela-García
- Department of Sustainable Engineering, Advanced Materials Research Center (CIMAV), Arroyo Seco, Durango, Mexico
| | - Eduardo A Robleto
- School of Life Sciences, University of Nevada, Las Vegas, Nevada, USA
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2
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Rs N, Sinha SK, Batra S, Regatti PR, Syal K. Promoter characterization of relZ-bifunctional (pp)pGpp synthetase in mycobacteria. Genes Cells 2024. [PMID: 38923083 DOI: 10.1111/gtc.13135] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/19/2024] [Revised: 05/30/2024] [Accepted: 06/03/2024] [Indexed: 06/28/2024]
Abstract
The second messenger guanosine 3',5'-bis(diphosphate)/guanosine tetraphosphate (ppGpp) and guanosine 3'-diphosphate 5'-triphosphate/guanosine pentaphosphate (pppGpp) ((p)ppGpp) has been shown to be crucial for the survival of mycobacteria under hostile conditions. Unexpectedly, deletion of primary (p)ppGpp synthetase-Rel did not completely diminish (p)ppGpp levels leading to the discovery of novel bifunctional enzyme-RelZ, which displayed guanosine 5'-monophosphate,3'-diphosphate (pGpp), ppGpp, and pppGpp ((pp)pGpp) synthesis and RNAseHII activity. What conditions does it express itself under, and does it work in concert with Rel? The regulation of its transcription and whether the Rel enzyme plays a role in such regulation remain unclear. In this article, we have studied relZ promoter and compared its activity with rel promoter in different growth conditions. We observed that the promoter activity of relZ was constitutive; it is weaker than rel promoter, lies within 200 bp upstream of translation-start site, and it increased under carbon starvation. Furthermore, the promoter activity of relZ was compromised in the rel-knockout strain in the stationary phase. Our study unveils the dynamic regulation of relZ promoter activity by SigA and SigB sigma factors in different growth phases in mycobacteria. Importantly, elucidating the regulatory network of RelZ would enable the development of the targeted interventions for treating mycobacterial infections.
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Affiliation(s)
- Neethu Rs
- Genetics and Molecular Microbiology Laboratory, Department of Biological Sciences, Institute of Eminence, Birla Institute of Technology and Sciences-Pilani, Hyderabad, Telangana, India
| | - Shubham Kumar Sinha
- Genetics and Molecular Microbiology Laboratory, Department of Biological Sciences, Institute of Eminence, Birla Institute of Technology and Sciences-Pilani, Hyderabad, Telangana, India
| | - Sakshi Batra
- Genetics and Molecular Microbiology Laboratory, Department of Biological Sciences, Institute of Eminence, Birla Institute of Technology and Sciences-Pilani, Hyderabad, Telangana, India
- Department of Pulmonary Medicine, Malla Reddy Institute of Medical Sciences, Hyderabad, Telangana, India
| | - Pavan Reddy Regatti
- Genetics and Molecular Microbiology Laboratory, Department of Biological Sciences, Institute of Eminence, Birla Institute of Technology and Sciences-Pilani, Hyderabad, Telangana, India
| | - Kirtimaan Syal
- Genetics and Molecular Microbiology Laboratory, Department of Biological Sciences, Institute of Eminence, Birla Institute of Technology and Sciences-Pilani, Hyderabad, Telangana, India
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3
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Liu X, Wang P, Yuan N, Zhai Y, Yang Y, Hao M, Zhang M, Zhou D, Liu W, Jin Y, Wang A. The (p)ppGpp synthetase Rsh promotes rifampicin tolerant persister cell formation in Brucella abortus by regulating the type II toxin-antitoxin module mbcTA. Front Microbiol 2024; 15:1395504. [PMID: 38841069 PMCID: PMC11150624 DOI: 10.3389/fmicb.2024.1395504] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/04/2024] [Accepted: 05/01/2024] [Indexed: 06/07/2024] Open
Abstract
Persister cells are transiently tolerant to antibiotics and are associated with recalcitrant chronic infections due to recolonization of host cells after antibiotic removal. Brucella spp. are facultative pathogens that establish intracellular infection cycles in host cells which results in chronic persistent infections. Brucella abortus forms multi-drug persister cells which are promoted by the (p)ppGpp synthetase Rsh during rifampicin exposure. Here, we confirmed that Rsh promoted persister cells formation in B. abortus stationary phase treated with rifampicin and enrofloxacin. Deletion of the gene for Rsh decreased persister cells level in the presence of these drugs in different growth phases. However, persister cells formation by deletion strain varied in different growth phases in the presence of other antibiotics. Rsh also was involved in persister cells formation during rifampicin treatment under certain stress conditions, including acidic conditions, exposure to PBS, and heat stress. Moreover, Rsh impacted persister cell levels during rifampicin or enrofloxacin treatment in RAW264.7 macrophages. Certain typeIItoxin-antitoxin modules were upregulated under various stress conditions in B. abortus. We established that Rsh positively regulated the type II toxin-antitoxin mbcTA. Moreover, rifampicin-tolerant persister cells formation was elevated and ATP levels were decreased when mbcTA promoter was overexpressed in Rsh deletion background in stationary phase. Our results establish that (p)ppGpp synthetase Rsh plays a key role in B. abortus persistence and may serve as a potent novel target in combination with rifampicin in the development of new therapeutic approaches and prevention strategies to treat chronic infections of Brucella.
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Affiliation(s)
- Xiaofang Liu
- College of Veterinary Medicine, Northwest A&F University, Xianyang, China
- Key Laboratory of Animal Biotechnology of the Ministry of Agriculture, Northwest A&F University, Xianyang, China
| | - Pingping Wang
- College of Veterinary Medicine, Northwest A&F University, Xianyang, China
- Key Laboratory of Animal Biotechnology of the Ministry of Agriculture, Northwest A&F University, Xianyang, China
| | - Ningqiu Yuan
- College of Veterinary Medicine, Northwest A&F University, Xianyang, China
- Key Laboratory of Animal Biotechnology of the Ministry of Agriculture, Northwest A&F University, Xianyang, China
| | - Yunyi Zhai
- College of Veterinary Medicine, Northwest A&F University, Xianyang, China
- Key Laboratory of Animal Biotechnology of the Ministry of Agriculture, Northwest A&F University, Xianyang, China
| | - Yuanhao Yang
- College of Veterinary Medicine, Northwest A&F University, Xianyang, China
- Key Laboratory of Animal Biotechnology of the Ministry of Agriculture, Northwest A&F University, Xianyang, China
| | - Mingyue Hao
- College of Veterinary Medicine, Northwest A&F University, Xianyang, China
- Key Laboratory of Animal Biotechnology of the Ministry of Agriculture, Northwest A&F University, Xianyang, China
| | - Mingxing Zhang
- College of Veterinary Medicine, Northwest A&F University, Xianyang, China
- College of Animal Science and Technology, Northwest A&F University, Xianyang, China
| | - Dong Zhou
- College of Veterinary Medicine, Northwest A&F University, Xianyang, China
- Key Laboratory of Animal Biotechnology of the Ministry of Agriculture, Northwest A&F University, Xianyang, China
| | - Wei Liu
- College of Veterinary Medicine, Northwest A&F University, Xianyang, China
- Key Laboratory of Animal Biotechnology of the Ministry of Agriculture, Northwest A&F University, Xianyang, China
| | - Yaping Jin
- College of Veterinary Medicine, Northwest A&F University, Xianyang, China
- Key Laboratory of Animal Biotechnology of the Ministry of Agriculture, Northwest A&F University, Xianyang, China
| | - Aihua Wang
- College of Veterinary Medicine, Northwest A&F University, Xianyang, China
- Key Laboratory of Animal Biotechnology of the Ministry of Agriculture, Northwest A&F University, Xianyang, China
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4
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Decourcey MA, Davis WC, de Souza C. Use of RNA-seq to identify genes encoding cytokines and chemokines activated following uptake and processing a candidate peptide vaccine developed against Mycobacterium avium subsp. paratuberculosis. BRAZILIAN JOURNAL OF VETERINARY MEDICINE 2024; 46:e002723. [PMID: 38282832 PMCID: PMC10811724 DOI: 10.29374/2527-2179.bjvm002723] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/10/2023] [Accepted: 12/20/2023] [Indexed: 01/30/2024] Open
Abstract
Analysis of the primary and recall responses to a membrane molecule (MMP), encoded by MAP2121c demonstrated that tri-directional signaling between the antigen-presenting cell (APC), CD4 and CD8 is essential for eliciting a CD8 cytotoxic T cell (CTL) response against Mycobacterium avium subsp. paratuberculosis. As reported here, RNA-sequencing was used to initiate the characterization of the signaling pathways involved in eliciting the development of CD8 CTL, starting with the characterization of the activation status of genes in monocyte-derived macrophages (MoMΦ) following uptake and processing MMP for the presentation of antigenic epitopes to CD4 and CD8 T cells. Activation status was compared with the uptake and processing of LPS, a nonspecific stimulator of macrophages. 1609 genes were identified that were upregulated, and 1277 were downregulated three hours after uptake and processing MMP. No significant difference was observed in the cytokine genes selected for analysis of the signaling that must occur between APC, CD4, and CD8 for the development of CTL. The initial observations indicate screening of the transcriptome should include genes involved in signaling between APC and CD4, and CD8 regardless of their activation status. Four genes of interest in this study, IL12A, IL12B, IL15, and IL23A, were not significantly different from control values. The initial studies also indicate MoMΦ can be included with dendritic cells and monocyte-derived dendritic cells for further analysis of the tri-directional signaling required for the development of CTL.
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Affiliation(s)
- Michelle Athena Decourcey
- Veterinarian, Veterinary Medical Diagnostic Laboratory, University of Missouri College of Veterinary Medicine, Columbia, CO, USA
| | - William Charles Davis
- Veterinarian, PhD, Department of Veterinary Microbiology and Pathology, Washington State University, Pullman, WA, USA
| | - Cleverson de Souza
- Veterinarian Department of Comparative, Diagnostic & Population Medicine, University of Florida, Gainesville, FL, USA
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5
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Kago G, Turnbough CL, Salazar JC, Payne SM. (p)ppGpp is required for virulence of Shigella flexneri. Infect Immun 2024; 92:e0033423. [PMID: 38099658 PMCID: PMC10790822 DOI: 10.1128/iai.00334-23] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/22/2023] [Accepted: 11/16/2023] [Indexed: 01/17/2024] Open
Abstract
Infection by the enteric pathogen Shigella flexneri requires transit through the gastrointestinal tract and invasion of and replication within the cells of the host colonic epithelium. This process exposes the pathogen to a range of diverse microenvironments. Furthermore, the unique composition and physical environment of the eukaryotic cell cytosol represents a stressful environment for S. flexneri, and extensive physiological adaptations are needed for the bacterium to thrive. In this work, we show that disrupting synthesis of the stringent response alarmone (p)ppGpp in S. flexneri diminished expression of key virulence genes, including ipaA, ipaB, ipaC, and icsA, and it reduced bacterial invasion and intercellular spread. Deletion of the (p)ppGpp synthase gene relA alone had no effect on S. flexneri virulence, but disruption of both relA and the (p)ppGpp synthase/hydrolase gene spoT resulted in loss of (p)ppGpp synthesis and virulence. While the relA spoT deletion mutant was able to invade a cultured human epithelial cell monolayer, albeit at reduced levels, it was unable to maintain the infection and spread to adjacent cells, as indicated by loss of plaque formation. Complementation with spoT on a plasmid vector restored plaque formation. Thus, SpoT alone is sufficient to provide the necessary level of (p)ppGpp for virulence. These results indicate that (p)ppGpp is required for S. flexneri virulence and adaptation to the intracellular environment, adding to the repertoire of signaling pathways that affect Shigella pathogenesis.
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Affiliation(s)
- Grace Kago
- Department of Molecular Biosciences, University of Texas at Austin, Austin, Texas, USA
| | - Charles L. Turnbough
- Department of Microbiology, University of Alabama at Birmingham, Birmingham, Alabama, USA
| | - Juan Carlos Salazar
- Programa de Microbiología y Micología, ICBM, Facultad de Medicina, Universidad de Chile, Santiago, Chile
| | - Shelley M. Payne
- Department of Molecular Biosciences, University of Texas at Austin, Austin, Texas, USA
- John Ring LaMontagne Center for Infectious Disease, The University of Texas at Austin, Austin, Texas, USA
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6
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Alves da Silva A, Silva IJ, Arraiano CM. A paradox of bacterial persistence and antibiotic resistance: chloramphenicol acetyl transferase as a double barrel shot gun. MICROLIFE 2023; 4:uqad034. [PMID: 37781689 PMCID: PMC10540939 DOI: 10.1093/femsml/uqad034] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 06/15/2023] [Revised: 07/04/2023] [Accepted: 09/19/2023] [Indexed: 10/03/2023]
Abstract
The problematic microbial resistance to antibiotics has led to an increasing interest in bacterial persistence and its impact on infection. Nonetheless, these two mechanisms are often assessed in independent studies, and there is a lack of knowledge about their relation or possible interactions, both at cellular and population levels. This work shows evidence that the insertion of the resistance gene Chloramphenicol Acetyl Transferase (cat) together with its cognate antibiotic chloramphenicol (CAM), is capable to modulate Salmonella Typhimurium persistence to several antibiotics and decrease its survival. This effect is independent of the antibiotics' mechanisms of action or the locus of cat. RelA [p(ppGpp) syntetase] has been shown to be involved in persistence. It was recently proposed that RelA [(p)ppGpp synthetase], binds to uncharged tRNAs, forming RelA.tRNA complexes. These complexes bind to vacant A-sites in the ribosome, and this mechanism is essential for the activation of RelA. In this study, we propose that the antibiotic chloramphenicol blocks the A-site of the ribosome, hindering the binding of RelA.tRNA complexes to the ribosome thus preventing the activation of RelA and (p)ppGpp synthesis, with a consequent decrease in the level of persistence of the population. Our discovery that the concomitant use of chloramphenicol and other antibiotics in chloramphenicol resistant bacteria can decrease the persister levels can be the basis of novel therapeutics aiming to decrease the persisters and recalcitrant infections.
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Affiliation(s)
- Ana Alves da Silva
- Instituto de Tecnologia Química e Biológica António Xavier, Universidade Nova de Lisboa, Av. da República, 2780-157 Oeiras, Portugal
| | - Inês Jesus Silva
- Instituto de Tecnologia Química e Biológica António Xavier, Universidade Nova de Lisboa, Av. da República, 2780-157 Oeiras, Portugal
| | - Cecília Maria Arraiano
- Instituto de Tecnologia Química e Biológica António Xavier, Universidade Nova de Lisboa, Av. da República, 2780-157 Oeiras, Portugal
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7
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Hogins J, Xuan Z, Zimmern PE, Reitzer L. The distinct transcriptome of virulence-associated phylogenetic group B2 Escherichia coli. Microbiol Spectr 2023; 11:e0208523. [PMID: 37724859 PMCID: PMC10580932 DOI: 10.1128/spectrum.02085-23] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/18/2023] [Accepted: 07/28/2023] [Indexed: 09/21/2023] Open
Abstract
Escherichia coli strains of phylogenetic group B2 are often associated with urinary tract infections (UTIs) and several other diseases. Recent genomic and transcriptomic analyses have not suggested or identified specific genes required for virulence, but have instead suggested multiple virulence strategies and complex host-pathogen interactions. Previous analyses have not compared core gene expression between phylogenetic groups or between pathogens and nonpathogens within phylogenetic groups. We compared the core gene expression of 35 strains from three phylogenetic groups that included both pathogens and nonpathogens after growth in a medium that allowed comparable growth of both types of strains. K-means clustering suggested a B2 cluster with 17 group B2 strains and two group A strains; an AD cluster with six group A strains, five group D strains and one B2 strain; and four outliers which included the highly studied model uropathogenic E. coli strains UTI89 and CFT073. Half of the core genes were differentially expressed between B2 and AD cluster strains, including transcripts of genes for all aspects of macromolecular synthesis-replication, transcription, translation, and peptidoglycan synthesis-energy metabolism, and environmental-sensing transcriptional regulators. Notably, core gene expression between nonpathogenic and uropathogenic transcriptomes within phylogenetic groups did not differ. If differences between pathogens and nonpathogens exist, then the differences do not require transcriptional reprogramming. In summary, B2 cluster strains have a distinct transcription pattern that involves hundreds of genes. We propose that this transcription pattern is one factor that contributes to virulence. IMPORTANCE Escherichia coli is a diverse species and an opportunistic pathogen that is associated with various diseases, such as urinary tract infections. When examined, phylogenetic group B2 strains are more often associated with these diseases, but the specific properties that contribute to their virulence are not known. From a comparative transcriptomic analysis, we found that group B2 strains grown in a nutrient-rich medium had a distinct transcription pattern, which is the first evidence that core gene expression differs between phylogenetic groups. Understanding the consequences of group B2 transcription pattern will provide important information on basic E. coli biology, the basis for E. coli virulence, and possibly for developing therapies for a majority of urinary tract infections and other group B2-associated diseases.
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Affiliation(s)
- Jacob Hogins
- Department of Biological Sciences, The University of Texas at Dallas, Richardson, Texas, USA
| | - Zhenyu Xuan
- Department of Biological Sciences, The University of Texas at Dallas, Richardson, Texas, USA
| | - Philippe E. Zimmern
- Department of Urology, The University of Texas Southwestern, Dallas, Texas, USA
| | - Larry Reitzer
- Department of Biological Sciences, The University of Texas at Dallas, Richardson, Texas, USA
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Wan X, Chou WK, Brynildsen MP. Amino acids can deplete ATP and impair nitric oxide detoxification by Escherichia coli. Free Radic Biol Med 2023; 205:90-99. [PMID: 37253411 DOI: 10.1016/j.freeradbiomed.2023.05.016] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 03/09/2023] [Revised: 04/18/2023] [Accepted: 05/15/2023] [Indexed: 06/01/2023]
Abstract
Nitric oxide (·NO) is a prevalent antimicrobial that is known to damage iron-containing enzymes in amino acid (AA) biosynthesis pathways. With Escherichia coli, ·NO is detoxified in aerobic environments by Hmp, which is an enzyme that is synthesized de novo in response to ·NO. With this knowledgebase, it is expected that the availability of AAs in the extracellular environment would enhance ·NO detoxification, because AAs would foster translation of Hmp. However, we observed that ·NO detoxification by E. coli was far slower in populations grown and treated in the presence of AAs (AA+) in comparison to those grown and stressed in the absence of AAs (AA-). Further experiments revealed that AA+ populations had difficulty translating proteins under ·NO stress, and that ·NO activated the stringent response in AA+ populations. Additional work revealed significant ATP depletion in ·NO-stressed AA+ cultures that far exceeded that of ·NO-stressed AA- populations. Transcription, translation, and RelA were not found to be significant contributors to the ATP depletion observed, whereas AA import was implicated as a significant ATP consumption pathway. Alleviating ATP depletion while maintaining access to AAs partially restored ·NO detoxification, which suggested that ATP depletion contributed to the translational difficulties observed in ·NO-stressed AA+ populations. These data reveal an unexpected interaction within the ·NO response network of E. coli that stimulates a stringent response by RelA in conditions where AAs are plentiful.
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Affiliation(s)
- Xuanqing Wan
- Department of Chemical and Biological Engineering, Princeton University, Princeton, NJ, 08544, USA
| | - Wen Kang Chou
- Department of Chemical and Biological Engineering, Princeton University, Princeton, NJ, 08544, USA
| | - Mark P Brynildsen
- Department of Chemical and Biological Engineering, Princeton University, Princeton, NJ, 08544, USA.
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Wang M, Tang NY, Xie S, Watt RM. Functional Characterization of Small Alarmone Synthetase and Small Alarmone Hydrolase Proteins from Treponema denticola. Microbiol Spectr 2023; 11:e0510022. [PMID: 37289081 PMCID: PMC10434055 DOI: 10.1128/spectrum.05100-22] [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: 12/11/2022] [Accepted: 05/18/2023] [Indexed: 06/09/2023] Open
Abstract
The stringent response enables bacteria to survive nutrient starvation, antibiotic challenge, and other threats to cellular survival. Two alarmone (magic spot) second messengers, guanosine pentaphosphate (pppGpp) and guanosine tetraphosphate (ppGpp), which are synthesized by RelA/SpoT homologue (RSH) proteins, play central roles in the stringent response. The pathogenic oral spirochete bacterium Treponema denticola lacks a long-RSH homologue but encodes putative small alarmone synthetase (Tde-SAS, TDE1711) and small alarmone hydrolase (Tde-SAH, TDE1690) proteins. Here, we characterize the respective in vitro and in vivo activities of Tde-SAS and Tde-SAH, which respectively belong to the previously uncharacterized RSH families DsRel and ActSpo2. The tetrameric 410-amino acid (aa) Tde-SAS protein preferentially synthesizes ppGpp over pppGpp and a third alarmone, pGpp. Unlike RelQ homologues, alarmones do not allosterically stimulate the synthetic activities of Tde-SAS. The ~180 aa C-terminal tetratricopeptide repeat (TPR) domain of Tde-SAS acts as a brake on the alarmone synthesis activities of the ~220-aa N-terminal catalytic domain. Tde-SAS also synthesizes "alarmone-like" nucleotides such as adenosine tetraphosphate (ppApp), albeit at considerably lower rates. The 210-aa Tde-SAH protein efficiently hydrolyzes all guanosine and adenosine-based alarmones in a Mn(II) ion-dependent manner. Using a growth assays with a ΔrelAΔspoT strain of Escherichia coli that is deficient in pppGpp/ppGpp synthesis, we demonstrate that Tde-SAS can synthesize alarmones in vivo to restore growth in minimal media. Taken together, our results add to our holistic understanding of alarmone metabolism across diverse bacterial species. IMPORTANCE The spirochete bacterium Treponema denticola is a common component of the oral microbiota. However, it may play important pathological roles in multispecies oral infectious diseases such as periodontitis: a severe and destructive form of gum disease, which is a major cause of tooth loss in adults. The operation of the stringent response, a highly conserved survival mechanism, is known to help many bacterial species cause persistent or virulent infections. By characterizing the biochemical functions of the proteins putatively responsible for the stringent response in T. denticola, we may gain molecular insight into how this bacterium can survive within harsh oral environments and promote infection. Our results also expand our general understanding of proteins that synthesize nucleotide-based intracellular signaling molecules in bacteria.
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Affiliation(s)
- Miao Wang
- Faculty of Dentistry, The University of Hong Kong, Pok Fu Lam, Hong Kong SAR, China
| | - Nga-Yeung Tang
- Department of Pathology and Laboratory Medicine, Beaumont Health, Royal Oak, Michigan, USA
- Department of Pathology and Laboratory Medicine, Oakland University William Beaumont School of Medicine, Auburn Hills, Michigan, USA
| | - Shujie Xie
- Faculty of Dentistry, The University of Hong Kong, Pok Fu Lam, Hong Kong SAR, China
| | - Rory M. Watt
- Faculty of Dentistry, The University of Hong Kong, Pok Fu Lam, Hong Kong SAR, China
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10
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Sound the (Smaller) Alarm: The Triphosphate Magic Spot Nucleotide pGpp. Infect Immun 2023; 91:e0043222. [PMID: 36920208 PMCID: PMC10112252 DOI: 10.1128/iai.00432-22] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 03/16/2023] Open
Abstract
It has recently become evident that the bacterial stringent response is regulated by a triphosphate alarmone (pGpp) as well as the canonical tetra- and pentaphosphate alarmones ppGpp and pppGpp [together, (p)ppGpp]. Often dismissed in the past as an artifact or degradation product, pGpp has been confirmed as a deliberate endpoint of multiple synthetic pathways utilizing GMP, (p)ppGpp, or GDP/GTP as precursors. Some early studies concluded that pGpp functionally mimics (p)ppGpp and that its biological role is to make alarmone metabolism less dependent on the guanine energy charge of the cell by allowing GMP-dependent synthesis to continue when GDP/GTP has been depleted. However, recent reports that pGpp binds unique potential protein receptors and is the only alarmone synthesized by the intestinal pathogen Clostridioides difficile indicate that pGpp is more than a stand-in for the longer alarmones and plays a distinct biological role beyond its functional overlap (p)ppGpp.
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11
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Tamman H, Ernits K, Roghanian M, Ainelo A, Julius C, Perrier A, Talavera A, Ainelo H, Dugauquier R, Zedek S, Thureau A, Pérez J, Lima-Mendez G, Hallez R, Atkinson GC, Hauryliuk V, Garcia-Pino A. Structure of SpoT reveals evolutionary tuning of catalysis via conformational constraint. Nat Chem Biol 2023; 19:334-345. [PMID: 36470996 PMCID: PMC9974481 DOI: 10.1038/s41589-022-01198-x] [Citation(s) in RCA: 6] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/24/2022] [Accepted: 10/05/2022] [Indexed: 12/12/2022]
Abstract
Stringent factors orchestrate bacterial cell reprogramming through increasing the level of the alarmones (p)ppGpp. In Beta- and Gammaproteobacteria, SpoT hydrolyzes (p)ppGpp to counteract the synthetase activity of RelA. However, structural information about how SpoT controls the levels of (p)ppGpp is missing. Here we present the crystal structure of the hydrolase-only SpoT from Acinetobacter baumannii and uncover the mechanism of intramolecular regulation of 'long'-stringent factors. In contrast to ribosome-associated Rel/RelA that adopt an elongated structure, SpoT assumes a compact τ-shaped structure in which the regulatory domains wrap around a Core subdomain that controls the conformational state of the enzyme. The Core is key to the specialization of long RelA-SpoT homologs toward either synthesis or hydrolysis: the short and structured Core of SpoT stabilizes the τ-state priming the hydrolase domain for (p)ppGpp hydrolysis, whereas the longer, more dynamic Core domain of RelA destabilizes the τ-state priming the monofunctional RelA for efficient (p)ppGpp synthesis.
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Affiliation(s)
- Hedvig Tamman
- Cellular and Molecular Microbiology, Faculté des Sciences, Université libre de Bruxelles (ULB), Boulevard du Triomphe, Brussels, Belgium.
| | - Karin Ernits
- Department of Experimental Medicine, University of Lund, Lund, Sweden
- Department of Chemistry, Umeå University, Umeå, Sweden
- Department of Molecular Biology, Umeå University, Umeå, Sweden
| | - Mohammad Roghanian
- Department of Experimental Medicine, University of Lund, Lund, Sweden
- Department of Molecular Biology, Umeå University, Umeå, Sweden
- Departement of Clinical Microbiology, Rigshospitalet, Copenhagen, Denmark
| | - Andres Ainelo
- Cellular and Molecular Microbiology, Faculté des Sciences, Université libre de Bruxelles (ULB), Boulevard du Triomphe, Brussels, Belgium
| | | | - Anthony Perrier
- Biology of Microorganisms Research Unit, Namur Research Institute for Life Science, University of Namur, Namur, Belgium
- Bacterial Cell Cycle and Development, Biology of Microorganisms Research Unit, Namur Research Institute for Life Science, University of Namur, Namur, Belgium
| | - Ariel Talavera
- Cellular and Molecular Microbiology, Faculté des Sciences, Université libre de Bruxelles (ULB), Boulevard du Triomphe, Brussels, Belgium
| | - Hanna Ainelo
- Cellular and Molecular Microbiology, Faculté des Sciences, Université libre de Bruxelles (ULB), Boulevard du Triomphe, Brussels, Belgium
| | - Rémy Dugauquier
- Cellular and Molecular Microbiology, Faculté des Sciences, Université libre de Bruxelles (ULB), Boulevard du Triomphe, Brussels, Belgium
- Biology of Microorganisms Research Unit, Namur Research Institute for Life Science, University of Namur, Namur, Belgium
| | - Safia Zedek
- Cellular and Molecular Microbiology, Faculté des Sciences, Université libre de Bruxelles (ULB), Boulevard du Triomphe, Brussels, Belgium
| | | | - Javier Pérez
- Synchrotron SOLEIL, Saint-Aubin - BP 48, Gif sur Yvette, France
| | - Gipsi Lima-Mendez
- Biology of Microorganisms Research Unit, Namur Research Institute for Life Science, University of Namur, Namur, Belgium
| | - Régis Hallez
- Biology of Microorganisms Research Unit, Namur Research Institute for Life Science, University of Namur, Namur, Belgium
- Bacterial Cell Cycle and Development, Biology of Microorganisms Research Unit, Namur Research Institute for Life Science, University of Namur, Namur, Belgium
- WELBIO, Brussels, Belgium
| | - Gemma C Atkinson
- Department of Experimental Medicine, University of Lund, Lund, Sweden
- Department of Molecular Biology, Umeå University, Umeå, Sweden
| | - Vasili Hauryliuk
- Department of Experimental Medicine, University of Lund, Lund, Sweden.
- Department of Molecular Biology, Umeå University, Umeå, Sweden.
- University of Tartu, Institute of Technology, Tartu, Estonia.
| | - Abel Garcia-Pino
- Cellular and Molecular Microbiology, Faculté des Sciences, Université libre de Bruxelles (ULB), Boulevard du Triomphe, Brussels, Belgium.
- WELBIO, Brussels, Belgium.
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12
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Increased Levels of (p)ppGpp Correlate with Virulence and Biofilm Formation, but Not with Growth, in Strains of Uropathogenic Escherichia coli. Int J Mol Sci 2023; 24:ijms24043315. [PMID: 36834725 PMCID: PMC9962837 DOI: 10.3390/ijms24043315] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/21/2022] [Revised: 01/26/2023] [Accepted: 02/06/2023] [Indexed: 02/10/2023] Open
Abstract
Urinary tract infections are one of the most frequent bacterial diseases worldwide. UPECs are the most prominent group of bacterial strains among pathogens responsible for prompting such infections. As a group, these extra-intestinal infection-causing bacteria have developed specific features that allow them to sustain and develop in their inhabited niche of the urinary tract. In this study, we examined 118 UPEC isolates to determine their genetic background and antibiotic resistance. Moreover, we investigated correlations of these characteristics with the ability to form biofilm and to induce a general stress response. We showed that this strain collection expressed unique UPEC attributes, with the highest representation of FimH, SitA, Aer, and Sfa factors (100%, 92.5%, 75%, and 70%, respectively). According to CRA (Congo red agar) analysis, the strains particularly predisposed to biofilm formation represented 32.5% of the isolates. Those biofilm forming strains presented a significant ability to accumulate multi-resistance traits. Most notably, these strains presented a puzzling metabolic phenotype-they showed elevated basal levels of (p)ppGpp in the planktonic phase and simultaneously exhibited a shorter generation time when compared to non-biofilm-forming strains. Moreover, our virulence analysis showed these phenotypes to be crucial for the development of severe infections in the Galleria mellonella model.
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13
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DEAD Box Protein DhR1 Is a Global Regulator Involved in the Bacterial Fitness and Virulence of Riemerella anatipestifer. J Bacteriol 2023; 205:e0034122. [PMID: 36598230 PMCID: PMC9879107 DOI: 10.1128/jb.00341-22] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/05/2023] Open
Abstract
DEAD box proteins perform diverse cellular functions in bacteria. Our group previously reported that the transposon Tn4531 insertion in Riean_0395 (designated dhR1), which encodes a putative DEAD box helicase, attenuated the virulence of R. anatipestifer strain YZb1. Here, we show that, compared to the wild-type (WT) R. anatipestifer strain Yb2, the growth or survival of the ΔdhR1 mutant in tryptic soy broth (TSB) was significantly decreased in response to cold, pH, osmotic stress, ethanol, Triton X-100, and oxidative stress, and the dhR1 deletion significantly reduced biofilm formation and the adhesion capacity to Vero cells, whereas the growth of ΔdhR1 was less impaired in iron-limited TSB. Moreover, the virulence of ΔdhR1 in ducklings was attenuated by about 80-fold, compared to the WT. In addition, a transcriptome analysis showed that the dhR1 deletion in the strain Yb2 affected the expression of 58 upregulated genes and 98 downregulated genes that are responsible for various functions. Overall, our work reveals that the deletion of DhR1 results in a broad effect on the bacterial fitness, biofilm formation, iron utilization, and virulence of R. anatipestifer, which makes it a global regulator. IMPORTANCE R. anatipestifer infection has been a continued and serious problem in many duck farms, but little is known about the mechanism underlying the pathogenesis of R. anatipestifer and how R. anatipestifer adapts to the external environment and thereby persists in duck farms. The results of this study demonstrate that the DEAD box protein DhR1 is required for the tolerance of R. anatipestifer to cold, pH, and other stresses, and it is also necessary for biofilm formation, iron utilization, and virulence in ducklings, demonstrating multiple functions of DhR1.
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14
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Molecular Characterization of Clinical Rel Mutations and Consequences for Resistance Expression and Fitness in Staphylococcus aureus. Antimicrob Agents Chemother 2022; 66:e0093822. [PMID: 36346240 PMCID: PMC9764984 DOI: 10.1128/aac.00938-22] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022] Open
Abstract
The stringent response (SR) is a universal stress response that acts as a global regulator of bacterial physiology and virulence, and is a contributor to antibiotic tolerance and resistance. In most bacteria, the SR is controlled by a bifunctional enzyme, Rel, which both synthesizes and hydrolyzes the alarmone (p)ppGpp via two distinct catalytic domains. The balance between these antagonistic activities is fine-tuned to the needs of the cell and, in a "relaxed" state, the hydrolase activity of Rel dominates. We have previously shown that two single amino acid substitutions in Rel (that were identified in clinical isolates from persistent infections) confer elevated basal concentrations of (p)ppGpp and consequent multidrug tolerance in Staphylococcus aureus. Here, we explore the molecular details of how these mutations bring about this increase in cellular (p)ppGpp and investigate the wider cellular consequences in terms of resistance expression, resistance development, and bacterial fitness. Using enzyme assays, we show that both these mutations drastically reduce the hydrolase activity of Rel, thereby shifting the balance of Rel activity in favor of (p)ppGpp synthesis. We also demonstrate that these mutations induce high-level, homogeneous expression of β-lactam resistance and confer a significant fitness advantage in the presence of bactericidal antibiotics (but a fitness cost in the absence of antibiotic). In contrast, these mutations do not appear to accelerate the emergence of endogenous resistance mutations in vitro. Overall, our findings reveal the complex nature of Rel regulation and the multifaceted implications of clinical Rel mutations in terms of antibiotic efficacy and bacteria survival.
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15
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Fernández-Vázquez J, Cabrer-Panes JD, Åberg A, Juárez A, Madrid C, Gaviria-Cantin T, Fernández-Coll L, Vargas-Sinisterra AF, Jiménez CJ, Balsalobre C. ppGpp, the General Stress Response Alarmone, Is Required for the Expression of the α-Hemolysin Toxin in the Uropathogenic Escherichia coli Isolate, J96. Int J Mol Sci 2022; 23:ijms232012256. [PMID: 36293122 PMCID: PMC9602796 DOI: 10.3390/ijms232012256] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/03/2022] [Revised: 10/11/2022] [Accepted: 10/12/2022] [Indexed: 11/08/2022] Open
Abstract
ppGpp is an intracellular sensor that, in response to different types of stress, coordinates the rearrangement of the gene expression pattern of bacteria to promote adaptation and survival to new environmental conditions. First described to modulate metabolic adaptive responses, ppGpp modulates the expression of genes belonging to very diverse functional categories. In Escherichia coli, ppGpp regulates the expression of cellular factors that are important during urinary tract infections. Here, we characterize the role of this alarmone in the regulation of the hlyCABDII operon of the UPEC isolate J96, encoding the toxin α-hemolysin that induces cytotoxicity during infection of bladder epithelial cells. ppGpp is required for the expression of the α-hemolysin encoded in hlyCABDII by stimulating its transcriptional expression. Prototrophy suppressor mutations in a ppGpp-deficient strain restore the α-hemolysin expression from this operon to wild-type levels, confirming the requirement of ppGpp for its expression. ppGpp stimulates hlyCABDII expression independently of RpoS, RfaH, Zur, and H-NS. The expression of hlyCABDII is promoted at 37 °C and at low osmolarity. ppGpp is required for the thermoregulation but not for the osmoregulation of the hlyCABDII operon. Studies in both commensal and UPEC isolates demonstrate that no UPEC specific factor is strictly required for the ppGpp-mediated regulation described. Our data further support the role of ppGpp participating in the coordinated regulation of the expression of bacterial factors required during infection.
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Affiliation(s)
- Jorge Fernández-Vázquez
- Department of Genetics, Microbiology and Statistics, School of Biology, University of Barcelona, 08028 Barcelona, Spain
| | - Juan David Cabrer-Panes
- Department of Genetics, Microbiology and Statistics, School of Biology, University of Barcelona, 08028 Barcelona, Spain
| | - Anna Åberg
- Department of Medical Biochemistry and Biophysics, Umeå University, SE-90187 Umeå, Sweden
| | - Antonio Juárez
- Department of Genetics, Microbiology and Statistics, School of Biology, University of Barcelona, 08028 Barcelona, Spain
- Institute for Bioengineering of Catalonia, The Barcelona Institute of Science and Technology, 08028 Barcelona, Spain
| | - Cristina Madrid
- Department of Genetics, Microbiology and Statistics, School of Biology, University of Barcelona, 08028 Barcelona, Spain
| | - Tania Gaviria-Cantin
- Department of Genetics, Microbiology and Statistics, School of Biology, University of Barcelona, 08028 Barcelona, Spain
| | - Llorenç Fernández-Coll
- Department of Genetics, Microbiology and Statistics, School of Biology, University of Barcelona, 08028 Barcelona, Spain
| | | | - Carlos Jonay Jiménez
- Department of Genetics, Microbiology and Statistics, School of Biology, University of Barcelona, 08028 Barcelona, Spain
| | - Carlos Balsalobre
- Department of Genetics, Microbiology and Statistics, School of Biology, University of Barcelona, 08028 Barcelona, Spain
- Correspondence: ; Tel.: +34-934-034-622
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16
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Ali IAA, Cheung GS, Neelakantan P. Transition Metals and
Enterococcus faecalis
: Homeostasis, Virulence and Perspectives. Mol Oral Microbiol 2022; 37:276-291. [DOI: 10.1111/omi.12391] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/06/2022] [Accepted: 09/07/2022] [Indexed: 11/29/2022]
Affiliation(s)
- Islam A. A. Ali
- Department of Endodontics Faculty of Dentistry Mansoura University Mansoura Egypt
| | - Gary S.P. Cheung
- Discipline of Endodontology Division of Restorative Dental Sciences Faculty of Dentistry The University of Hong Kong Hong Kong SAR
| | - Prasanna Neelakantan
- Discipline of Endodontology Division of Restorative Dental Sciences Faculty of Dentistry The University of Hong Kong Hong Kong SAR
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17
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Martínez OF, Duque HM, Franco OL. Peptidomimetics as Potential Anti-Virulence Drugs Against Resistant Bacterial Pathogens. Front Microbiol 2022; 13:831037. [PMID: 35516442 PMCID: PMC9062693 DOI: 10.3389/fmicb.2022.831037] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/07/2021] [Accepted: 02/28/2022] [Indexed: 12/11/2022] Open
Abstract
The uncontrollable spread of superbugs calls for new approaches in dealing with microbial-antibiotic resistance. Accordingly, the anti-virulence approach has arisen as an attractive unconventional strategy to face multidrug-resistant pathogens. As an emergent strategy, there is an imperative demand for discovery, design, and development of anti-virulence drugs. In this regard, peptidomimetic compounds could be a valuable source of anti-virulence drugs, since these molecules circumvent several shortcomings of natural peptide-based drugs like proteolytic instability, immunogenicity, toxicity, and low bioavailability. Some emerging evidence points to the feasibility of peptidomimetics to impair pathogen virulence. Consequently, in this review, we shed some light on the potential of peptidomimetics as anti-virulence drugs to overcome antibiotic resistance. Specifically, we address the anti-virulence activity of peptidomimetics against pathogens' secretion systems, biofilms, and quorum-sensing systems.
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Affiliation(s)
- Osmel Fleitas Martínez
- Programa de Pós-Graduação em Ciências Genômicas e Biotecnologia, Centro de Análises Proteômicas e Bioquímicas, Universidade Católica de Brasília, Brasília, Brazil.,Programa de Pós-Graduação em Biotecnologia, S-Inova Biotech, Universidade Católica Dom Bosco, Campo Grande, Brazil
| | - Harry Morales Duque
- Programa de Pós-Graduação em Ciências Genômicas e Biotecnologia, Centro de Análises Proteômicas e Bioquímicas, Universidade Católica de Brasília, Brasília, Brazil
| | - Octávio Luiz Franco
- Programa de Pós-Graduação em Ciências Genômicas e Biotecnologia, Centro de Análises Proteômicas e Bioquímicas, Universidade Católica de Brasília, Brasília, Brazil.,Programa de Pós-Graduação em Biotecnologia, S-Inova Biotech, Universidade Católica Dom Bosco, Campo Grande, Brazil
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18
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Davis WC, Mahmoud AH, Abdellrazeq GS, Elnaggar MM, Dahl JL, Hulubei V, Fry LM. Ex vivo Platforms to Study the Primary and Recall Immune Responses to Intracellular Mycobacterial Pathogens and Peptide-Based Vaccines. Front Vet Sci 2022; 9:878347. [PMID: 35591875 PMCID: PMC9111181 DOI: 10.3389/fvets.2022.878347] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/17/2022] [Accepted: 04/01/2022] [Indexed: 11/29/2022] Open
Abstract
Progress in the study of the immune response to pathogens and candidate vaccines has been impeded by limitations in the methods to study the functional activity of T-cell subsets proliferating in response to antigens processed and presented by antigen presenting cells (APC). As described in this review, during our studies of the bovine immune response to a candidate peptide-based vaccine and candidate rel deletion mutants in Mycobacterium avium paratuberculosis (Map) and Mycbacterium bovis (BCG), we developed methods to study the primary and recall CD4 and CD8 T-cell responses using an ex vivo platform. An assay was developed to study intracellular killing of bacteria mediated by CD8 T cells using quantitative PCR to distinguish live bacteria from dead bacteria in a mixed population of live and dead bacteria. Through use of these assays, we were able to demonstrate vaccination with live rel Map and BCG deletion mutants and a Map peptide-based vaccine elicit development of CD8 cytotoxic T cells with the ability to kill intracellular bacteria using the perforin-granzyme B pathway. We also demonstrated tri-directional signaling between CD4 and CD8 T cells and antigen-primed APC is essential for eliciting CD8 cytotoxic T cells. Herein, we describe development of the assays and review progress made through their use in the study of the immune response to mycobacterial pathogens and candidate vaccines. The methods obviate some of the major difficulties encountered in characterizing the cell-mediated immune response to pathogens and development of attenuated and peptide-based vaccines.
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Affiliation(s)
- William C. Davis
- Department of Veterinary Microbiology and Pathology, Washington State University, Pullman, WA, United States
- *Correspondence: William C. Davis
| | - Asmaa H. Mahmoud
- Department of Veterinary Microbiology and Pathology, Washington State University, Pullman, WA, United States
- Veterinary Quarantine of Alexandria, General Organization for Veterinary Services, Ministry of Agriculture and Land Reclamation, Cairo, Egypt
| | - Gaber S. Abdellrazeq
- Department of Veterinary Microbiology and Pathology, Washington State University, Pullman, WA, United States
- Department of Microbiology, Faculty of Veterinary Medicine, Alexandria University, Alexandria, Egypt
| | - Mahmoud M. Elnaggar
- Department of Microbiology, Faculty of Veterinary Medicine, Alexandria University, Alexandria, Egypt
| | - John L. Dahl
- Department of Biology, University of Minnesota Duluth, Duluth, MN, United States
| | - Victoria Hulubei
- Department of Veterinary Microbiology and Pathology, Washington State University, Pullman, WA, United States
| | - Lindsay M. Fry
- Department of Veterinary Microbiology and Pathology, Washington State University, Pullman, WA, United States
- Animal Disease Research Unit, USDA-ARS, Pullman, WA, United States
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19
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Zhao H, Wang M, Cui Y, Zhang C. Can We Arrest the Evolution of Antibiotic Resistance? The Differences between the Effects of Silver Nanoparticles and Silver Ions. ENVIRONMENTAL SCIENCE & TECHNOLOGY 2022; 56:5090-5101. [PMID: 35344362 DOI: 10.1021/acs.est.2c00116] [Citation(s) in RCA: 5] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/14/2023]
Abstract
Silver nanoparticles (AgNPs) are effective antimicrobial substances that show promise in combatting multidrug resistance. The potential application and release of AgNPs into the environment may neutralize the selective advantage of antibiotic resistance. Systemic knowledge regarding the effect of NPs on the evolution of antibiotic resistance is lacking. Our results showed that bacteria slowly developed adaptive tolerance to ciprofloxacin (CIP) under cyclic CIP and silver ion (Ag+) cotreatment, and no resistance/tolerance was discernible when CIP and AgNP exposure was alternated. In contrast, rapid CIP resistance was induced under continuous selection by treatment with only CIP. To combat the effects of CIP and Ag+, bacteria developed convergent evolutionary strategies with similar adaptive mechanisms, including anaerobic respiration transitioning (to reduce oxidative stress) and stringent response (to survive harsh environments). Alternating AgNP exposure impeded evolutionary resistance by accelerating B12-dependent folate and methionine cycles, which reestablished DNA synthesis and partially offset high oxidative stress levels, in contrast with the effect of CIP-directed evolutionary pressure. Nevertheless, CIP/AgNP treatment was ineffective in attenuating virulence, and CIP/Ag+ exposure even induced the virulence-critical type III secretion system. Our results increase the basic understanding of the impacts of NPs on evolutionary biology and suggest prospective nanotechnology applications for arresting evolutionary antibiotic resistance.
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Affiliation(s)
- Huiru Zhao
- School of Environment, Beijing Normal University, Beijing 100875, China
- College of Environmental Science and Engineering, Nankai University, Tianjin 300350, China
| | - Meiling Wang
- College of Environmental Science and Engineering, Nankai University, Tianjin 300350, China
| | - Yueting Cui
- School of Environment, Beijing Normal University, Beijing 100875, China
| | - Chengdong Zhang
- School of Environment, Beijing Normal University, Beijing 100875, China
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20
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Joshi C, Kothari V. Bacterial Stress-response Machinery as a Target for Next-generation Antimicrobials. Infect Disord Drug Targets 2022; 22:e210322202493. [PMID: 35319398 DOI: 10.2174/1871526522666220321153332] [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: 10/16/2021] [Revised: 10/30/2021] [Accepted: 12/29/2021] [Indexed: 06/14/2023]
Affiliation(s)
- Chinmayi Joshi
- Smt. S.S.Patel Nootan Science and Commerce College, Sankalchand Patel University, Visnagar 384315, India
| | - Vijay Kothari
- Institute of Science, Nirma University, Ahmedabad 382481, India
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21
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Purcell EB. Second messenger signaling in Clostridioides difficile. Curr Opin Microbiol 2021; 65:138-144. [PMID: 34864551 DOI: 10.1016/j.mib.2021.11.006] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/04/2021] [Revised: 11/09/2021] [Accepted: 11/10/2021] [Indexed: 12/18/2022]
Abstract
Small, diffusible second messenger molecules transmit information about extracellular conditions to intracellular machinery in order to influence transcription, translation, and metabolism. The enteropathogenic bacterium Clostridioides difficile coordinates its response to a dynamic and hostile environment via nucleotide second messengers. While riboswitch-mediated cyclic diguanylate regulation has been extensively characterized in C. difficile, signaling by cyclic diadenylate and by guanosine alarmones has only recently been confirmed in this organism. This review summarizes the current knowledge of how nucleotide second messenger signaling regulates physiological processes in C. difficile.
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Affiliation(s)
- Erin B Purcell
- Old Dominion University, Department of Chemistry and Biochemistry, 4501 Elkhorn Ave, Norfolk, VA 23529, United States.
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22
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Anderson BW, Fung DK, Wang JD. Regulatory Themes and Variations by the Stress-Signaling Nucleotide Alarmones (p)ppGpp in Bacteria. Annu Rev Genet 2021; 55:115-133. [PMID: 34416118 DOI: 10.1146/annurev-genet-021821-025827] [Citation(s) in RCA: 38] [Impact Index Per Article: 12.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
Abstract
Bacterial stress-signaling alarmones are important components of a protective network against diverse stresses such as nutrient starvation and antibiotic assault. pppGpp and ppGpp, collectively (p)ppGpp, have well-documented regulatory roles in gene expression and protein translation. Recent work has highlighted another key function of (p)ppGpp: inducing rapid and coordinated changes in cellular metabolism by regulating enzymatic activities, especially those involved in purine nucleotide synthesis. Failure of metabolic regulation by (p)ppGpp results in the loss of coordination between metabolic and macromolecular processes, leading to cellular toxicity. In this review, we document how (p)ppGpp and newly characterized nucleotides pGpp and (p)ppApp directly regulate these enzymatic targets for metabolic remodeling. We examine targets' common determinants for alarmone interaction as well as their evolutionary diversification. We highlight classical and emerging themes in nucleotide signaling, including oligomerization and allostery along with metabolic interconversion and crosstalk, illustrating how they allow optimized bacterial adaptation to their environmental niches.
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Affiliation(s)
- Brent W Anderson
- Department of Bacteriology, University of Wisconsin-Madison, Madison, Wisconsin 53706, USA; , ,
| | - Danny K Fung
- Department of Bacteriology, University of Wisconsin-Madison, Madison, Wisconsin 53706, USA; , ,
| | - Jue D Wang
- Department of Bacteriology, University of Wisconsin-Madison, Madison, Wisconsin 53706, USA; , ,
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23
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Pulschen AA, Fernandes AZN, Cunha AF, Sastre DE, Matsuguma BE, Gueiros-Filho FJ. Many birds with one stone: targeting the (p)ppGpp signaling pathway of bacteria to improve antimicrobial therapy. Biophys Rev 2021; 13:1039-1051. [DOI: 10.1007/s12551-021-00895-6] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/25/2021] [Accepted: 10/25/2021] [Indexed: 12/19/2022] Open
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24
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Davis WC, Abdellrazeq GS, Mahmoud AH, Park KT, Elnaggar MM, Donofrio G, Hulubei V, Fry LM. Advances in Understanding of the Immune Response to Mycobacterial Pathogens and Vaccines through Use of Cattle and Mycobacterium avium subsp. paratuberculosis as a Prototypic Mycobacterial Pathogen. Vaccines (Basel) 2021; 9:vaccines9101085. [PMID: 34696193 PMCID: PMC8541111 DOI: 10.3390/vaccines9101085] [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: 08/15/2021] [Revised: 09/19/2021] [Accepted: 09/23/2021] [Indexed: 01/29/2023] Open
Abstract
Lack of understanding of the immune response to mycobacterial pathogens has impeded progress in development of vaccines. Infection leads to development of an immune response that controls infection but is unable to eliminate the pathogen, resulting in a persistent infection. Although this puzzle remains to be solved, progress has been made using cattle as a model species to study the immune response to a prototypic mycobacterium, Mycobacterium a. paratuberculosis (Map). As chronicled in the review, incremental advances in characterizing the immune response to mycobacteria during the last 30 years with increases in information on the evolution of mycobacteria and relA, a gene regulating the stringent response, have brought us closer to an answer. We provide a brief overview of how mycobacterial pathogens were introduced into cattle during the transition of humankind to nomadic pastoralists who domesticated animals for food and farming. We summarize what is known about speciation of mycobacteria since the discovery of Mybacterium tuberculsis Mtb, M. bovis Mbv, and Map as zoonotic pathogens and discuss the challenges inherent in the development of vaccines to mycobacteria. We then describe how cattle were used to characterize the immune response to a prototypic mycobacterial pathogen and development of novel candidate vaccines.
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Affiliation(s)
- William C. Davis
- Department of Veterinary Microbiology and Pathology, Washington State University, Pullman, WA 99164, USA; (G.S.A.); (A.H.M.); (M.M.E.); (V.H.); (L.M.F.)
- Correspondence:
| | - Gaber S. Abdellrazeq
- Department of Veterinary Microbiology and Pathology, Washington State University, Pullman, WA 99164, USA; (G.S.A.); (A.H.M.); (M.M.E.); (V.H.); (L.M.F.)
- Department of Microbiology, Faculty of Veterinary Medicine, Alexandria University, Alexandria 22758, Egypt
| | - Asmaa H. Mahmoud
- Department of Veterinary Microbiology and Pathology, Washington State University, Pullman, WA 99164, USA; (G.S.A.); (A.H.M.); (M.M.E.); (V.H.); (L.M.F.)
- Veterinary Quarantine of Alexandria, General Organization for Veterinary Services, Ministry of Agriculture and Land Reclamation, Dokki, Giza 12611, Egypt
| | - Kun-Taek Park
- Department of Biotechnology, Inje University, Injero 197, Kimhae-si 50834, Korea;
| | - Mahmoud M. Elnaggar
- Department of Veterinary Microbiology and Pathology, Washington State University, Pullman, WA 99164, USA; (G.S.A.); (A.H.M.); (M.M.E.); (V.H.); (L.M.F.)
- Department of Microbiology, Faculty of Veterinary Medicine, Alexandria University, Alexandria 22758, Egypt
| | - Gaetano Donofrio
- Department of Medical-Veterinary Science, University of Parma, 43126 Parma, Italy;
| | - Victoria Hulubei
- Department of Veterinary Microbiology and Pathology, Washington State University, Pullman, WA 99164, USA; (G.S.A.); (A.H.M.); (M.M.E.); (V.H.); (L.M.F.)
| | - Lindsay M. Fry
- Department of Veterinary Microbiology and Pathology, Washington State University, Pullman, WA 99164, USA; (G.S.A.); (A.H.M.); (M.M.E.); (V.H.); (L.M.F.)
- Animal Disease Research Unit, USDA-ARS, Pullman, WA 99164, USA
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