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Li R, Liu J, Liu M, Liang M, Wang Z, Sha Y, Ma H, Lin Y, Li B, You J, Zhang L, Qin M. Effects of selenium-enriched yeast dietary supplementation on egg quality, gut morphology and caecal microflora of laying hens. Anim Biotechnol 2024; 35:2258188. [PMID: 38193802 DOI: 10.1080/10495398.2023.2258188] [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] [Indexed: 01/10/2024]
Abstract
Selenium (Se) is an essential micronutrient for humans and animals and is a powerful antioxidant that can promote reproductive and immune functions. The purpose of this study was to evaluate the effects of supplemental dietary selenium-enriched yeast (SeY) on egg quality, gut morphology and microflora in laying hens. In total, 100 HY-Line Brown laying hens (45-week old) were randomly allocated to two groups with 10 replicates and fed either a basal diet (without Se supplementation) or a basal diet containing 0.2 mg/kg Se in the form of SeY for 8 weeks. The Se supplementation did not have a significant effect on egg quality and intestinal morphology of laying hens. Based on the 16S rRNA sequencing, SeY dietary supplementation effectively modulated the cecal microbiota structure. An alpha diversity analysis demonstrated that birds fed 100 mg/kg SeY had a higher cecal bacterial diversity. SeY dietary addition elevated Erysipelotrichia (class), Lachnospiraceae (family), Erysipelotrichaceae (family) and Ruminococcus_torques_group (genus; p < .05). Analysis of microbial community-level phenotypes revealed that SeY supplementation decreased the microorganism abundance of facultatively anaerobic and potentially pathogenic phenotypes. Overall, SeY supplementation cannot significantly improve intestinal morphology; however, it modulated the composition of cecal microbiota toward a healthier gut.
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Affiliation(s)
- Ruili Li
- Institute of Animal Science and Veterinary Medicine, Yantai Academy of Agricultural Sciences, Yantai, China
| | - Jiewei Liu
- College of Animal Science and Technology, Jiangxi Agriculture University, Nanchang, China
| | - Minxiao Liu
- Institute of Animal Science and Veterinary Medicine, Yantai Academy of Agricultural Sciences, Yantai, China
| | - Mingzhi Liang
- Institute of Animal Science and Veterinary Medicine, Yantai Academy of Agricultural Sciences, Yantai, China
| | - Zengguang Wang
- Institute of Animal Science and Veterinary Medicine, Yantai Academy of Agricultural Sciences, Yantai, China
| | - Yufen Sha
- Institute of Animal Science and Veterinary Medicine, Yantai Academy of Agricultural Sciences, Yantai, China
| | - Huiwen Ma
- Yantai Animal Disease Prevention and Control Center, Yantai, China
| | - Yafeng Lin
- Yantai Agricultural Technology Extension Center, Yantai, China
| | - Baohua Li
- Haiyang Animal Disease Prevention and Control Center, Yantai, China
| | - Jinming You
- College of Animal Science and Technology, Jiangxi Agriculture University, Nanchang, China
| | - Lei Zhang
- Institute of Animal Science and Veterinary Medicine, Yantai Academy of Agricultural Sciences, Yantai, China
| | - Ming Qin
- Institute of Animal Science and Veterinary Medicine, Yantai Academy of Agricultural Sciences, Yantai, China
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Hallenbeck M, Chua M, Collins J. The role of the universal sugar transport system components PtsI (EI) and PtsH (HPr) in Enterococcus faecium. FEMS MICROBES 2024; 5:xtae018. [PMID: 38988831 PMCID: PMC11234649 DOI: 10.1093/femsmc/xtae018] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/13/2024] [Revised: 05/08/2024] [Accepted: 05/31/2024] [Indexed: 07/12/2024] Open
Abstract
Vancomycin-resistant enterococci (VRE) pose a serious threat to public health because of their limited treatment options. Therefore, there is an increasing need to identify novel targets to develop new drugs. Here, we examined the roles of the universal PTS components, PtsI and PtsH, in Enterococcus faecium to determine their roles in carbon metabolism, biofilm formation, stress response, and the ability to compete in the gastrointestinal tract. Clean deletion of ptsHI resulted in a significant reduction in the ability to import and metabolize simple sugars, attenuated growth rate, reduced biofilm formation, and decreased competitive fitness both in vitro and in vivo. However, no significant difference in stress survival was observed when compared with the wild type. These results suggest that targeting universal or specific PTS may provide a novel treatment strategy by reducing the fitness of E. faecium.
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Affiliation(s)
- Michelle Hallenbeck
- Department of Microbiology & Immunology, University of Louisville, Louisville, KY 40202, United States
- Center for Predictive Medicine, University of Louisville, Louisville, KY 40202, United States
| | - Michelle Chua
- Department of Microbiology & Immunology, University of Louisville, Louisville, KY 40202, United States
- Center for Predictive Medicine, University of Louisville, Louisville, KY 40202, United States
| | - James Collins
- Department of Microbiology & Immunology, University of Louisville, Louisville, KY 40202, United States
- Center for Predictive Medicine, University of Louisville, Louisville, KY 40202, United States
- Center for Microbiomics, Inflammation and Pathogenicity, University of Louisville, Louisville, KY 40202, United States
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3
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Sedinkin SL, Roche J, Venditti V. Elucidation of the Mechanisms of Inter-domain Coupling in the Monomeric State of Enzyme I by High-pressure NMR. J Mol Biol 2024; 436:168553. [PMID: 38548260 PMCID: PMC11042970 DOI: 10.1016/j.jmb.2024.168553] [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: 02/14/2024] [Revised: 03/20/2024] [Accepted: 03/22/2024] [Indexed: 04/09/2024]
Abstract
The catalytic cycle of Enzyme I (EI), a phosphotransferase enzyme responsible for converting phosphoenolpyruvate (PEP) into pyruvate, is characterized by a series of local and global conformational rearrangements. This multistep process includes a monomer-to-dimer transition, followed by an open-to-closed rearrangement of the dimeric complex upon PEP binding. In the present study, we investigate the thermodynamics of EI dimerization using a range of high-pressure solution NMR techniques complemented by SAXS experiments. 1H-15N TROSY and 1H-13C methyl TROSY NMR spectra combined with 15N relaxation measurements revealed that a native-like engineered variant of full-length EI fully dissociates into stable monomeric state above 1.5 kbar. Conformational ensembles of EI monomeric state were generated via a recently developed protocol combining coarse-grained molecular simulations with experimental backbone residual dipolar coupling measurements. Analysis of the structural ensembles provided detailed insights into the molecular mechanisms driving formation of the catalytically competent dimeric state, and reveals that each step of EI catalytical cycle is associated with a significant reduction in either inter- or intra-domain conformational entropy. Altogether, this study completes a large body work conducted by our group on EI and establishes a comprehensive structural and dynamical description of the catalytic cycle of this prototypical multidomain, oligomeric enzyme.
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Affiliation(s)
- Sergey L Sedinkin
- Department of Chemistry, Iowa State University, Ames, IA 50011, United States
| | - Julien Roche
- Roy J. Carver Department of Biochemistry, Biophysics and Molecular Biology, Iowa State University, Ames, IA 50011, United States.
| | - Vincenzo Venditti
- Department of Chemistry, Iowa State University, Ames, IA 50011, United States; Roy J. Carver Department of Biochemistry, Biophysics and Molecular Biology, Iowa State University, Ames, IA 50011, United States.
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Wimmi S, Fleck M, Helbig C, Brianceau C, Langenfeld K, Szymanski WG, Angelidou G, Glatter T, Diepold A. Pilotins are mobile T3SS components involved in assembly and substrate specificity of the bacterial type III secretion system. Mol Microbiol 2024; 121:304-323. [PMID: 38178634 DOI: 10.1111/mmi.15223] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/23/2023] [Revised: 12/17/2023] [Accepted: 12/20/2023] [Indexed: 01/06/2024]
Abstract
In animal pathogens, assembly of the type III secretion system injectisome requires the presence of so-called pilotins, small lipoproteins that assist the formation of the secretin ring in the outer membrane. Using a combination of functional assays, interaction studies, proteomics, and live-cell microscopy, we determined the contribution of the pilotin to the assembly, function, and substrate selectivity of the T3SS and identified potential new downstream roles of pilotin proteins. In absence of its pilotin SctG, Yersinia enterocolitica forms few, largely polar injectisome sorting platforms and needles. Accordingly, most export apparatus subcomplexes are mobile in these strains, suggesting the absence of fully assembled injectisomes. Remarkably, while absence of the pilotin all but prevents export of early T3SS substrates, such as the needle subunits, it has little effect on secretion of late T3SS substrates, including the virulence effectors. We found that although pilotins interact with other injectisome components such as the secretin in the outer membrane, they mostly localize in transient mobile clusters in the bacterial membrane. Together, these findings provide a new view on the role of pilotins in the assembly and function of type III secretion injectisomes.
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Affiliation(s)
- Stephan Wimmi
- Department of Ecophysiology, Max Planck Institute for Terrestrial Microbiology, Marburg, Germany
| | - Moritz Fleck
- Department of Ecophysiology, Max Planck Institute for Terrestrial Microbiology, Marburg, Germany
| | - Carlos Helbig
- Department of Ecophysiology, Max Planck Institute for Terrestrial Microbiology, Marburg, Germany
| | - Corentin Brianceau
- Department of Ecophysiology, Max Planck Institute for Terrestrial Microbiology, Marburg, Germany
| | - Katja Langenfeld
- Department of Ecophysiology, Max Planck Institute for Terrestrial Microbiology, Marburg, Germany
| | - Witold G Szymanski
- Mass Spectrometry and Proteomics Facility, Max Planck Institute for Terrestrial Microbiology, Marburg, Germany
| | - Georgia Angelidou
- Mass Spectrometry and Proteomics Facility, Max Planck Institute for Terrestrial Microbiology, Marburg, Germany
| | - Timo Glatter
- Mass Spectrometry and Proteomics Facility, Max Planck Institute for Terrestrial Microbiology, Marburg, Germany
| | - Andreas Diepold
- Department of Ecophysiology, Max Planck Institute for Terrestrial Microbiology, Marburg, Germany
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Huang G, Zhou Y, Cheng H, Lv T, Zheng L, Li C, Chen Y. Genome and transcriptome analysis of Enterococcus faecium from intestinal colonization and Enterococcus faecium from urinary tract infection. Front Microbiol 2023; 14:1273949. [PMID: 38029192 PMCID: PMC10644037 DOI: 10.3389/fmicb.2023.1273949] [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: 08/07/2023] [Accepted: 10/12/2023] [Indexed: 12/01/2023] Open
Abstract
Introduction Enterococcus faecium is a common pathogen responsible for urinary tract infections (UTIs) and often establishes extensive colonization within the intestinal tract. Our aim was to assess the genomic and transcriptomic differences between colonized E. faecium without UTI (only-colonization) and colonized E. faecium causing UTI (endogenous infections). Method We investigated the correlation between fecal isolates from the same patient and UTI-causing isolates using PFGE and WGS, and classified fecal isolates into two groups: those that solely colonized and those associated with endogenous urinary tract infections. We characterized the genomes of colonization-only and endogenously infected isolates by Scoary GWAS, and the transcriptomes of the isolates at 3 h urine exposure to assess pathogen-related changes. Result Based on PFGE and WGS, eight isolates of endogenously infected E. faecium and nine isolates of only-colonized E. faecium were characterized and carbon and nitrogen regulated metabolisms such as genes encoding the phosphotransferase (PTS) system were enriched in endogenously infected E. faecium. Transcriptome analysis revealed significant differences in gene expression in the PTS system, lysine synthesis, galactose metabolism and citrate import between endogenously infected and only-colonized E. faecium isolates, highlighting the important role of certain carbon regulatory genes in the colonization and survival of endogenously infected E. faecium. Conclusion In only-colonized and endogenously infected isolates, we observed differential expression patterns of genes related to carbon metabolism and amino acids, suggesting that metabolic diversity is a strategy for isolates leading to endogenous infection.
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Affiliation(s)
- Ge Huang
- Department of Clinical Laboratory Center, Central Hospital of Enshi Tujia and Miao Autonomous Prefecture, Enshi, China
- Jingzhou Hospital Affiliated to Yangtze University, Jingzhou, China
| | - Yizheng Zhou
- Jingzhou Hospital Affiliated to Yangtze University, Jingzhou, China
| | - Hai Cheng
- Jingzhou Hospital Affiliated to Yangtze University, Jingzhou, China
| | - Tao Lv
- State Key Laboratory for Diagnosis and Treatment of Infectious Diseases, Collaborative Innovation Center for Diagnosis and Treatment of Infectious Diseases, The First Affiliated Hospital, School of Medicine, Zhejiang University, Hangzhou, China
| | - Lisi Zheng
- State Key Laboratory for Diagnosis and Treatment of Infectious Diseases, Collaborative Innovation Center for Diagnosis and Treatment of Infectious Diseases, The First Affiliated Hospital, School of Medicine, Zhejiang University, Hangzhou, China
| | - Chengbin Li
- Jingzhou Hospital Affiliated to Yangtze University, Jingzhou, China
| | - Yunbo Chen
- State Key Laboratory for Diagnosis and Treatment of Infectious Diseases, Collaborative Innovation Center for Diagnosis and Treatment of Infectious Diseases, The First Affiliated Hospital, School of Medicine, Zhejiang University, Hangzhou, China
- Jinan Microecological Biomedicine Shandong Laboratory, Jinan, China
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Shearer HL, Pace PE, Smith LM, Fineran PC, Matthews AJ, Camilli A, Dickerhof N, Hampton MB. Identification of Streptococcus pneumoniae genes associated with hypothiocyanous acid tolerance through genome-wide screening. J Bacteriol 2023; 205:e0020823. [PMID: 37791755 PMCID: PMC10601753 DOI: 10.1128/jb.00208-23] [Citation(s) in RCA: 5] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/05/2023] [Accepted: 09/01/2023] [Indexed: 10/05/2023] Open
Abstract
Streptococcus pneumoniae is a commensal bacterium and invasive pathogen that causes millions of deaths worldwide. The pneumococcal vaccine offers limited protection, and the rise of antimicrobial resistance will make treatment increasingly challenging, emphasizing the need for new antipneumococcal strategies. One possibility is to target antioxidant defenses to render S. pneumoniae more susceptible to oxidants produced by the immune system. Human peroxidase enzymes will convert bacterial-derived hydrogen peroxide to hypothiocyanous acid (HOSCN) at sites of colonization and infection. Here, we used saturation transposon mutagenesis and deep sequencing to identify genes that enable S. pneumoniae to tolerate HOSCN. We identified 37 genes associated with S. pneumoniae HOSCN tolerance, including genes involved in metabolism, membrane transport, DNA repair, and oxidant detoxification. Single-gene deletion mutants of the identified antioxidant defense genes sodA, spxB, trxA, and ahpD were generated and their ability to survive HOSCN was assessed. With the exception of ΔahpD, all deletion mutants showed significantly greater sensitivity to HOSCN, validating the result of the genome-wide screen. The activity of hypothiocyanous acid reductase or glutathione reductase, known to be important for S. pneumoniae tolerance of HOSCN, was increased in three of the mutants, highlighting the compensatory potential of antioxidant systems. Double deletion of the gene encoding glutathione reductase and sodA sensitized the bacteria significantly more than single deletion. The HOSCN defense systems identified in this study may be viable targets for novel therapeutics against this deadly pathogen. IMPORTANCE Streptococcus pneumoniae is a human pathogen that causes pneumonia, bacteremia, and meningitis. Vaccination provides protection only against a quarter of the known S. pneumoniae serotypes, and the bacterium is rapidly becoming resistant to antibiotics. As such, new treatments are required. One strategy is to sensitize the bacteria to killing by the immune system. In this study, we performed a genome-wide screen to identify genes that help this bacterium resist oxidative stress exerted by the host at sites of colonization and infection. By identifying a number of critical pneumococcal defense mechanisms, our work provides novel targets for antimicrobial therapy.
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Affiliation(s)
- Heather L. Shearer
- Department of Pathology and Biomedical Science, Mātai Hāora - Centre for Redox Biology and Medicine, University of Otago Christchurch, Christchurch, New Zealand
- Maurice Wilkins Centre for Molecular Biodiscovery, University of Otago, Otago, New Zealand
| | - Paul E. Pace
- Department of Pathology and Biomedical Science, Mātai Hāora - Centre for Redox Biology and Medicine, University of Otago Christchurch, Christchurch, New Zealand
| | - Leah M. Smith
- Department of Microbiology and Immunology, University of Otago, Dunedin, New Zealand
- Genetics Otago, University of Otago, Dunedin, New Zealand
| | - Peter C. Fineran
- Maurice Wilkins Centre for Molecular Biodiscovery, University of Otago, Otago, New Zealand
- Department of Microbiology and Immunology, University of Otago, Dunedin, New Zealand
- Genetics Otago, University of Otago, Dunedin, New Zealand
- Bioprotection Aotearoa, University of Otago, Dunedin, New Zealand
| | - Allison J. Matthews
- Department of Molecular Biology and Microbiology, Tufts University School of Medicine, Boston, Massachusetts, USA
| | - Andrew Camilli
- Department of Molecular Biology and Microbiology, Tufts University School of Medicine, Boston, Massachusetts, USA
| | - Nina Dickerhof
- Department of Pathology and Biomedical Science, Mātai Hāora - Centre for Redox Biology and Medicine, University of Otago Christchurch, Christchurch, New Zealand
- Maurice Wilkins Centre for Molecular Biodiscovery, University of Otago, Otago, New Zealand
| | - Mark B. Hampton
- Department of Pathology and Biomedical Science, Mātai Hāora - Centre for Redox Biology and Medicine, University of Otago Christchurch, Christchurch, New Zealand
- Maurice Wilkins Centre for Molecular Biodiscovery, University of Otago, Otago, New Zealand
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Xu T, Tao X, He H, Kempher ML, Zhang S, Liu X, Wang J, Wang D, Ning D, Pan C, Ge H, Zhang N, He YX, Zhou J. Functional and structural diversification of incomplete phosphotransferase system in cellulose-degrading clostridia. THE ISME JOURNAL 2023; 17:823-835. [PMID: 36899058 PMCID: PMC10203250 DOI: 10.1038/s41396-023-01392-2] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/22/2022] [Revised: 02/21/2023] [Accepted: 02/23/2023] [Indexed: 05/24/2023]
Abstract
Carbohydrate utilization is critical to microbial survival. The phosphotransferase system (PTS) is a well-documented microbial system with a prominent role in carbohydrate metabolism, which can transport carbohydrates through forming a phosphorylation cascade and regulate metabolism by protein phosphorylation or interactions in model strains. However, those PTS-mediated regulated mechanisms have been underexplored in non-model prokaryotes. Here, we performed massive genome mining for PTS components in nearly 15,000 prokaryotic genomes from 4,293 species and revealed a high prevalence of incomplete PTSs in prokaryotes with no association to microbial phylogeny. Among these incomplete PTS carriers, a group of lignocellulose degrading clostridia was identified to have lost PTS sugar transporters and carry a substitution of the conserved histidine residue in the core PTS component, HPr (histidine-phosphorylatable phosphocarrier). Ruminiclostridium cellulolyticum was then selected as a representative to interrogate the function of incomplete PTS components in carbohydrate metabolism. Inactivation of the HPr homolog reduced rather than increased carbohydrate utilization as previously indicated. In addition to regulating distinct transcriptional profiles, PTS associated CcpA (Catabolite Control Protein A) homologs diverged from previously described CcpA with varied metabolic relevance and distinct DNA binding motifs. Furthermore, the DNA binding of CcpA homologs is independent of HPr homolog, which is determined by structural changes at the interface of CcpA homologs, rather than in HPr homolog. These data concordantly support functional and structural diversification of PTS components in metabolic regulation and bring novel understanding of regulatory mechanisms of incomplete PTSs in cellulose-degrading clostridia.
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Affiliation(s)
- Tao Xu
- Section on Pathophysiology and Molecular Pharmacology, Joslin Diabetes Center, Boston, MA, USA
- Department of Microbiology and Immunobiology, Harvard Medical School, Boston, MA, USA
- Institute for Environmental Genomics, and Department of Microbiology and Plant Biology, University of Oklahoma, Norman, OK, USA
| | - Xuanyu Tao
- Institute for Environmental Genomics, and Department of Microbiology and Plant Biology, University of Oklahoma, Norman, OK, USA
| | - Hongxi He
- School of Life Sciences, Anhui University, Hefei, 230601, PR China
- Institutes of Material Science and Information Technology, Anhui University, Hefei, 230601, PR China
| | - Megan L Kempher
- Institute for Environmental Genomics, and Department of Microbiology and Plant Biology, University of Oklahoma, Norman, OK, USA
| | - Siping Zhang
- Ministry of Education Key Laboratory of Cell Activities and Stress Adaptations, School of Life Sciences, Lanzhou University, Lanzhou, 730000, PR China
| | - Xiaochun Liu
- School of Life Sciences, Anhui University, Hefei, 230601, PR China
- Institutes of Material Science and Information Technology, Anhui University, Hefei, 230601, PR China
| | - Jun Wang
- School of Life Sciences, Anhui University, Hefei, 230601, PR China
- Institutes of Material Science and Information Technology, Anhui University, Hefei, 230601, PR China
| | - Dongyu Wang
- Department of Microbiology and Plant Biology, University of Oklahoma, Norman, OK, USA
| | - Daliang Ning
- Institute for Environmental Genomics, and Department of Microbiology and Plant Biology, University of Oklahoma, Norman, OK, USA
| | - Chongle Pan
- Department of Microbiology and Plant Biology, University of Oklahoma, Norman, OK, USA
- School of computer science, University of Oklahoma, Norman, OK, USA
| | - Honghua Ge
- School of Life Sciences, Anhui University, Hefei, 230601, PR China
- Institutes of Material Science and Information Technology, Anhui University, Hefei, 230601, PR China
| | - Nannan Zhang
- School of Life Sciences, Anhui University, Hefei, 230601, PR China.
- Institutes of Material Science and Information Technology, Anhui University, Hefei, 230601, PR China.
| | - Yong-Xing He
- Ministry of Education Key Laboratory of Cell Activities and Stress Adaptations, School of Life Sciences, Lanzhou University, Lanzhou, 730000, PR China.
| | - Jizhong Zhou
- Institute for Environmental Genomics, and Department of Microbiology and Plant Biology, University of Oklahoma, Norman, OK, USA.
- School of Civil Engineering and Environmental Sciences, University of Oklahoma, Norman, OK, USA.
- Earth and Environmental Sciences, Lawrence Berkeley National Laboratory, Berkeley, CA, USA.
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Transcriptome Analyses of Prophage in Mediating Persistent Methicillin-Resistant Staphylococcus aureus Endovascular Infection. Genes (Basel) 2022; 13:genes13091527. [PMID: 36140695 PMCID: PMC9498598 DOI: 10.3390/genes13091527] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/30/2022] [Revised: 08/23/2022] [Accepted: 08/23/2022] [Indexed: 12/24/2022] Open
Abstract
Persistent methicillin-resistant Staphylococcus aureus (MRSA) endovascular infections represent a significant subset of S. aureus infections and correlate with exceptionally high mortality. We have recently demonstrated that the lysogenization of prophage ϕSA169 from a clinical persistent MRSA bacteremia isolate (300-169) into a clinical resolving bacteremia MRSA isolate (301-188) resulted in the acquisition of well-defined in vitro and in vivo phenotypic and genotypic profiles related to persistent outcome. However, the underlying mechanism(s) of this impact is unknown. In the current study, we explored the genetic mechanism that may contribute to the ϕSA169-correlated persistence using RNA sequencing. Transcriptomic analyses revealed that the most significant impacts of ϕSA169 were: (i) the enhancement of fatty acid biosynthesis and purine and pyrimidine metabolic pathways; (ii) the repression of galactose metabolism and phosphotransferase system (PTS); and (iii) the down-regulation of the mutual prophage genes in both 300-169 and 301-188 strains. In addition, the influence of different genetic backgrounds between 300-169 and 301-188 might also be involved in the persistent outcome. These findings may provide targets for future studies on the persistence of MRSA.
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Rahman MA, Amirkhani A, Chowdhury D, Mempin M, Molloy MP, Deva AK, Vickery K, Hu H. Proteome of Staphylococcus aureus Biofilm Changes Significantly with Aging. Int J Mol Sci 2022; 23:6415. [PMID: 35742863 PMCID: PMC9223533 DOI: 10.3390/ijms23126415] [Citation(s) in RCA: 15] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/17/2022] [Revised: 05/30/2022] [Accepted: 06/06/2022] [Indexed: 01/15/2023] Open
Abstract
Staphylococcus aureus is a notorious biofilm-producing pathogen that is frequently isolated from implantable medical device infections. As biofilm ages, it becomes more tolerant to antimicrobial treatment leading to treatment failure and necessitating the costly removal of infected devices. In this study, we performed in-solution digestion followed by TMT-based high-throughput mass spectrometry and investigated what changes occur in the proteome of S. aureus biofilm grown for 3-days and 12-days in comparison with 24 h planktonic. It showed that proteins associated with biosynthetic processes, ABC transporter pathway, virulence proteins, and shikimate kinase pathway were significantly upregulated in a 3-day biofilm, while proteins associated with sugar transporter, degradation, and stress response were downregulated. Interestingly, in a 3-day biofilm, we observed numerous proteins involved in the central metabolism pathways which could lead to biofilm growth under diverse environments by providing an alternative metabolic route to utilize energy. In 12-day biofilms, proteins associated with peptidoglycan biosynthesis, sugar transporters, and stress responses were upregulated, whereas proteins associated with ABC transporters, DNA replication, and adhesion proteins were downregulated. Gene Ontology analysis revealed that more proteins are involved in metabolic processes in 3dwb compared with 12dwb. Furthermore, we observed significant variations in the formation of biofilms resulting from changes in the level of metabolic activity in the different growth modes of biofilms that could be a significant factor in S. aureus biofilm maturation and persistence. Collectively, potential marker proteins were identified and further characterized to understand their exact role in S. aureus biofilm development, which may shed light on possible new therapeutic regimes in the treatment of biofilm-related implant-associated infections.
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Affiliation(s)
- Md. Arifur Rahman
- Surgical Infection Research Group, Faculty of Medicine, Health and Human Sciences, Macquarie University, Sydney 2109, Australia; (D.C.); (M.M.); (A.K.D.); (K.V.)
| | - Ardeshir Amirkhani
- Australian Proteome Analysis Facility, Macquarie University, Sydney 2109, Australia; (A.A.); (M.P.M.)
| | - Durdana Chowdhury
- Surgical Infection Research Group, Faculty of Medicine, Health and Human Sciences, Macquarie University, Sydney 2109, Australia; (D.C.); (M.M.); (A.K.D.); (K.V.)
| | - Maria Mempin
- Surgical Infection Research Group, Faculty of Medicine, Health and Human Sciences, Macquarie University, Sydney 2109, Australia; (D.C.); (M.M.); (A.K.D.); (K.V.)
| | - Mark P. Molloy
- Australian Proteome Analysis Facility, Macquarie University, Sydney 2109, Australia; (A.A.); (M.P.M.)
| | - Anand Kumar Deva
- Surgical Infection Research Group, Faculty of Medicine, Health and Human Sciences, Macquarie University, Sydney 2109, Australia; (D.C.); (M.M.); (A.K.D.); (K.V.)
| | - Karen Vickery
- Surgical Infection Research Group, Faculty of Medicine, Health and Human Sciences, Macquarie University, Sydney 2109, Australia; (D.C.); (M.M.); (A.K.D.); (K.V.)
| | - Honghua Hu
- Surgical Infection Research Group, Faculty of Medicine, Health and Human Sciences, Macquarie University, Sydney 2109, Australia; (D.C.); (M.M.); (A.K.D.); (K.V.)
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Ude Z, Flothkötter N, Sheehan G, Brennan M, Kavanagh K, Marmion CJ. Multi-targeted metallo-ciprofloxacin derivatives rationally designed and developed to overcome antimicrobial resistance. Int J Antimicrob Agents 2021; 58:106449. [PMID: 34644603 DOI: 10.1016/j.ijantimicag.2021.106449] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/23/2021] [Revised: 09/28/2021] [Accepted: 10/02/2021] [Indexed: 10/20/2022]
Abstract
Antimicrobial resistance is a major global threat to human health due to the rise, spread and persistence of multi-drug-resistant bacteria or 'superbugs'. There is an urgent need to develop novel chemotherapeutics to overcome this overarching challenge. The authors derivatized a clinically used fluoroquinolone antibiotic ciprofloxacin (Cip), and complexed it to a copper phenanthrene framework. This resulted in the development of two novel metallo-antibiotics of general formula [Cu(N,N)(CipHA)]NO3 where N,N represents a phenanthrene ligand and CipHA represents a hydroxamic acid of Cip derivative. Comprehensive studies, including a detailed proteomic study in which Staphylococcus aureus cells were exposed to the complexes, were undertaken to gain an insight into their mode of action. These new complexes possess potent antibacterial activity against S. aureus and methicillin-resistant S. aureus. In addition, they were found to be well tolerated in vivo in Galleria mellonella larvae, which has both functional and structural similarities to the innate immune system of mammals. These findings suggest that proteins involved in virulence, pathogenesis, and the synthesis of nucleotides and DNA repair mechanisms are most affected. In addition, both complexes affected similar cell pathways when compared with clinically used Cip, including cationic antimicrobial peptide resistance. The Cu-DPPZ-CipHA (DPPZ = dipyrido[3,2-a:2',3'-c]phenazine) analogue also induces cell leakage, which leads to an altered proteome indicative of reduced virulence and increased stress.
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Affiliation(s)
- Ziga Ude
- Centre for Synthesis and Chemical Biology, Department of Chemistry, RCSI, University of Medicine and Health Sciences, Dublin, Ireland
| | - Nils Flothkötter
- Centre for Synthesis and Chemical Biology, Department of Chemistry, RCSI, University of Medicine and Health Sciences, Dublin, Ireland
| | - Gerard Sheehan
- SSPC Pharma Research Centre, Department of Biology, Maynooth University, Maynooth, Co. Kildare, Ireland
| | - Marian Brennan
- School of Pharmacy and Biomolecular Sciences, RCSI, University of Medicine and Health Sciences, Dublin, Ireland
| | - Kevin Kavanagh
- SSPC Pharma Research Centre, Department of Biology, Maynooth University, Maynooth, Co. Kildare, Ireland.
| | - Celine J Marmion
- Centre for Synthesis and Chemical Biology, Department of Chemistry, RCSI, University of Medicine and Health Sciences, Dublin, Ireland.
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11
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Purslow JA, Thimmesch JN, Sivo V, Nguyen TT, Khatiwada B, Dotas RR, Venditti V. A Single Point Mutation Controls the Rate of Interconversion Between the g + and g - Rotamers of the Histidine 189 χ2 Angle That Activates Bacterial Enzyme I for Catalysis. Front Mol Biosci 2021; 8:699203. [PMID: 34307459 PMCID: PMC8295985 DOI: 10.3389/fmolb.2021.699203] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/23/2021] [Accepted: 06/29/2021] [Indexed: 11/13/2022] Open
Abstract
Enzyme I (EI) of the bacterial phosphotransferase system (PTS) is a master regulator of bacterial metabolism and a promising target for development of a new class of broad-spectrum antibiotics. The catalytic activity of EI is mediated by several intradomain, interdomain, and intersubunit conformational equilibria. Therefore, in addition to its relevance as a drug target, EI is also a good model for investigating the dynamics/function relationship in multidomain, oligomeric proteins. Here, we use solution NMR and protein design to investigate how the conformational dynamics occurring within the N-terminal domain (EIN) affect the activity of EI. We show that the rotameric g+-to-g− transition of the active site residue His189 χ2 angle is decoupled from the state A-to-state B transition that describes a ∼90° rigid-body rearrangement of the EIN subdomains upon transition of the full-length enzyme to its catalytically competent closed form. In addition, we engineered EIN constructs with modulated conformational dynamics by hybridizing EIN from mesophilic and thermophilic species, and used these chimeras to assess the effect of increased or decreased active site flexibility on the enzymatic activity of EI. Our results indicate that the rate of the autophosphorylation reaction catalyzed by EI is independent from the kinetics of the g+-to-g− rotameric transition that exposes the phosphorylation site on EIN to the incoming phosphoryl group. In addition, our work provides an example of how engineering of hybrid mesophilic/thermophilic chimeras can assist investigations of the dynamics/function relationship in proteins, therefore opening new possibilities in biophysics.
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Affiliation(s)
- Jeffrey A Purslow
- Department of Chemistry, Iowa State University, Ames, IA, United States
| | | | - Valeria Sivo
- Department of Environmental, Biological and Pharmaceutical Sciences and Technologies, Università Degli Studi Della Campania, Caserta, Italy
| | - Trang T Nguyen
- Department of Chemistry, Iowa State University, Ames, IA, United States
| | | | - Rochelle R Dotas
- Department of Chemistry, Iowa State University, Ames, IA, United States
| | - Vincenzo Venditti
- Department of Chemistry, Iowa State University, Ames, IA, United States.,Roy J. Carver Department of Biochemistry, Biophysics and Molecular Biology, Iowa State University, Ames, IA, United States
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12
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Structure elucidation of the elusive Enzyme I monomer reveals the molecular mechanisms linking oligomerization and enzymatic activity. Proc Natl Acad Sci U S A 2021; 118:2100298118. [PMID: 33975952 DOI: 10.1073/pnas.2100298118] [Citation(s) in RCA: 11] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/12/2022] Open
Abstract
Enzyme I (EI) is a phosphotransferase enzyme responsible for converting phosphoenolpyruvate (PEP) into pyruvate. This reaction initiates a five-step phosphorylation cascade in the bacterial phosphotransferase (PTS) transduction pathway. Under physiological conditions, EI exists in an equilibrium between a functional dimer and an inactive monomer. The monomer-dimer equilibrium is a crucial factor regulating EI activity and the phosphorylation state of the overall PTS. Experimental studies of EI's monomeric state have yet been hampered by the dimer's high thermodynamic stability, which prevents its characterization by standard structural techniques. In this study, we modified the dimerization domain of EI (EIC) by mutating three amino acids involved in the formation of intersubunit salt bridges. The engineered variant forms an active dimer in solution that can bind and hydrolyze PEP. Using hydrostatic pressure as an additional perturbation, we were then able to study the complete dissociation of the variant from 1 bar to 2.5 kbar in the absence and the presence of EI natural ligands. Backbone residual dipolar couplings collected under high-pressure conditions allowed us to determine the conformational ensemble of the isolated EIC monomeric state in solution. Our calculations reveal that three catalytic loops near the dimerization interface become unstructured upon monomerization, preventing the monomeric enzyme from binding its natural substrate. This study provides an atomic-level characterization of EI's monomeric state and highlights the role of the catalytic loops as allosteric connectors controlling both the activity and oligomerization of the enzyme.
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13
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Guo L, Wang J, Gou Y, Tan L, Liu H, Pan Y, Zhao Y. Comparative proteomics reveals stress responses of Vibrio parahaemolyticus biofilm on different surfaces: Internal adaptation and external adjustment. THE SCIENCE OF THE TOTAL ENVIRONMENT 2020; 731:138386. [PMID: 32417469 DOI: 10.1016/j.scitotenv.2020.138386] [Citation(s) in RCA: 18] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/07/2020] [Revised: 03/27/2020] [Accepted: 03/31/2020] [Indexed: 06/11/2023]
Abstract
Vibrio parahaemolyticus is a kind of gram-negative marine pathogen, which usually adheres to stainless steel (SS), glass (GS) and other abiotic surfaces in aquaculture and food processing in the form of biofilm and causes the spread of gastrointestinal illness. However, the deeply survival adaptation mechanism of V. parahaemolyticus biofilm cells on these contact surface remained unclear. Here, proteomics was used to investigated the physiological response of the V. parahaemolyticus biofilms cells to different abiotic surfaces (SS, GS and polystyrene (PS)). In addition, the effect of contact materials on the physical-chemical properties of biofilms are also characterized. Results showed that the expression of proteins of biofilm cells established on the SS surface were mainly related to the alleviation of metal ion stress and toxicity. The up-regulated proteins in the biofilm cells formed on the GS surface were mainly involved in the biological processes of sugar uptake, protein synthesis and bacterial chemotaxis. Meanwhile, the significantly expressed proteins in the biofilm cells formed on the PS surface were mainly involved in the cellular physiological activity of aromatic compound metabolism, osmotic stress and nutrient transport. All functional proteins mentioned above were closely related to the interaction characteristics of the contact surface and biofilm. This study provided an in-depth comparison of V. parahaemolyticus biofilm formation on these three abiotic surfaces, and presented a model in first time for the adaptation behavior of biofilm cells on different surfaces as affected by metal ion stress, nutrition, osmotic stress, and sugar utilization, which could facilitate an efficient control strategy for biofilm formation in industrial field.
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Affiliation(s)
- Linxia Guo
- College of Food Science & Technology, Shanghai Ocean University, Shanghai, China
| | - Jingjing Wang
- College of Food Science & Technology, Shanghai Ocean University, Shanghai, China; Laboratory of Quality and Safety Risk Assessment for Aquatic Products on Storage and Preservation (Shanghai), Ministry of Agriculture, Shanghai, China; Shanghai Engineering Research Center of Aquatic-Product Processing & Preservation, Shanghai, China; Department of Food Science, Foshan University, Foshan, 528000, China
| | - Yi Gou
- College of Food Science & Technology, Shanghai Ocean University, Shanghai, China
| | - Ling Tan
- College of Food Science & Technology, Shanghai Ocean University, Shanghai, China
| | - Haiquan Liu
- College of Food Science & Technology, Shanghai Ocean University, Shanghai, China; Laboratory of Quality and Safety Risk Assessment for Aquatic Products on Storage and Preservation (Shanghai), Ministry of Agriculture, Shanghai, China; Shanghai Engineering Research Center of Aquatic-Product Processing & Preservation, Shanghai, China; Engineering Research Center of Food Thermal-processing Technology, Shanghai Ocean University, Shanghai 201306, China
| | - Yingjie Pan
- College of Food Science & Technology, Shanghai Ocean University, Shanghai, China; Laboratory of Quality and Safety Risk Assessment for Aquatic Products on Storage and Preservation (Shanghai), Ministry of Agriculture, Shanghai, China; Shanghai Engineering Research Center of Aquatic-Product Processing & Preservation, Shanghai, China
| | - Yong Zhao
- College of Food Science & Technology, Shanghai Ocean University, Shanghai, China; Laboratory of Quality and Safety Risk Assessment for Aquatic Products on Storage and Preservation (Shanghai), Ministry of Agriculture, Shanghai, China; Shanghai Engineering Research Center of Aquatic-Product Processing & Preservation, Shanghai, China.
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14
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An allosteric pocket for inhibition of bacterial Enzyme I identified by NMR-based fragment screening. JOURNAL OF STRUCTURAL BIOLOGY-X 2020; 4:100034. [PMID: 32743545 PMCID: PMC7385036 DOI: 10.1016/j.yjsbx.2020.100034] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 06/04/2020] [Revised: 07/16/2020] [Accepted: 07/17/2020] [Indexed: 12/18/2022]
Abstract
Enzyme I (EI), which is the key enzyme to activate the bacterial phosphotransferase system, plays an important role in the regulation of several metabolic pathways and controls the biology of bacterial cells at multiple levels. The conservation and ubiquity of EI among different types of bacteria makes the enzyme a potential target for antimicrobial research. Here, we use NMR-based fragment screening to identify novel inhibitors of EI. We identify three molecular fragments that allosterically inhibit the phosphoryl transfer reaction catalyzed by EI by interacting with the enzyme at a surface pocket located more than 10 Å away from the substrate binding site. Interestingly, although the three molecules share the same binding pocket, we observe that two of the discovered EI ligands act as competitive inhibitors while the third ligand acts as a mixed inhibitor. Characterization of the EI-inhibitor complexes by NMR and Molecular Dynamics simulations reveals key interactions that perturb the fold of the active site and provides structural foundation for the different inhibitory activity of the identified molecular fragments. In particular, we show that contacts between the inhibitor and the side-chain of V292 are crucial to destabilize binding of the substrate to EI. In contrast, mixed inhibition is caused by additional contacts between the inhibitor and ⍺-helix 2 that perturb the active site structure and turnover in an allosteric manner. We expect our results to provide the basis for the development of second generation allosteric inhibitors of increased potency and to suggest novel molecular strategies to combat drug-resistant infections.
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15
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Dotas RR, Nguyen TT, Stewart CE, Ghirlando R, Potoyan DA, Venditti V. Hybrid Thermophilic/Mesophilic Enzymes Reveal a Role for Conformational Disorder in Regulation of Bacterial Enzyme I. J Mol Biol 2020; 432:4481-4498. [PMID: 32504625 DOI: 10.1016/j.jmb.2020.05.024] [Citation(s) in RCA: 19] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/16/2020] [Revised: 05/23/2020] [Accepted: 05/29/2020] [Indexed: 02/08/2023]
Abstract
Conformational disorder is emerging as an important feature of biopolymers, regulating a vast array of cellular functions, including signaling, phase separation, and enzyme catalysis. Here we combine NMR, crystallography, computer simulations, protein engineering, and functional assays to investigate the role played by conformational heterogeneity in determining the activity of the C-terminal domain of bacterial Enzyme I (EIC). In particular, we design chimeric proteins by hybridizing EIC from thermophilic and mesophilic organisms, and we characterize the resulting constructs for structure, dynamics, and biological function. We show that EIC exists as a mixture of active and inactive conformations and that functional regulation is achieved by tuning the thermodynamic balance between active and inactive states. Interestingly, we also present a hybrid thermophilic/mesophilic enzyme that is thermostable and more active than the wild-type thermophilic enzyme, suggesting that hybridizing thermophilic and mesophilic proteins is a valid strategy to engineer thermostable enzymes with significant low-temperature activity.
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Affiliation(s)
- Rochelle R Dotas
- Department of Chemistry, Iowa State University, Ames, IA 50011, USA
| | - Trang T Nguyen
- Department of Chemistry, Iowa State University, Ames, IA 50011, USA
| | - Charles E Stewart
- Macromolecular X-ray Crystallography Facility, Office of Biotechnology, Iowa State University, Ames, IA 50011, USA
| | - Rodolfo Ghirlando
- Laboratory of Molecular Biology, NIDDK, National Institutes of Health, Bethesda, MD 20892, USA
| | - Davit A Potoyan
- Department of Chemistry, Iowa State University, Ames, IA 50011, USA; Roy J. Carver Department of Biochemistry, Biophysics and Molecular Biology, Iowa State University, Ames, IA 50011, USA.
| | - Vincenzo Venditti
- Department of Chemistry, Iowa State University, Ames, IA 50011, USA; Roy J. Carver Department of Biochemistry, Biophysics and Molecular Biology, Iowa State University, Ames, IA 50011, USA.
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16
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Transporters of glucose and other carbohydrates in bacteria. Pflugers Arch 2020; 472:1129-1153. [PMID: 32372286 DOI: 10.1007/s00424-020-02379-0] [Citation(s) in RCA: 80] [Impact Index Per Article: 16.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/10/2019] [Revised: 04/01/2020] [Accepted: 04/02/2020] [Indexed: 12/18/2022]
Abstract
Glucose arguably is the most important energy carrier, carbon source for metabolites and building block for biopolymers in all kingdoms of life. The proper function of animal organs and tissues depends on the continuous supply of glucose from the bloodstream. Most animals can resorb only a small number of monosaccharides, mostly glucose, galactose and fructose, while all other sugars oligosaccharides and dietary fibers are degraded and metabolized by the microbiota of the lower intestine. Bacteria, in contrast, are omnivorous. They can import and metabolize structurally different sugars and, as a consortium of different species, utilize almost any sugar, sugar derivative and oligosaccharide occurring in nature. Bacteria have membrane transport systems for the uptake of sugars against steep concentration gradients energized by ATP, the proton motive force and the high energy glycolytic intermediate phosphoenolpyruvate (PEP). Different uptake mechanisms and the broad range of overlapping substrate specificities allow bacteria to quickly adapt to and colonize changing environments. Here, we review the structures and mechanisms of bacterial representatives of (i) ATP-dependent cassette (ABC) transporters, (ii) major facilitator (MFS) superfamily proton symporters, (iii) sodium solute symporters (SSS) and (iv) enzyme II integral membrane subunits of the bacterial PEP-dependent phosphotransferase system (PTS). We give a short overview on the distribution of transporter genes and their phylogenetic relationship in different bacterial species. Some sugar transporters are hijacked for import of bacteriophage DNA and antibacterial toxins (bacteriocins) and they facilitate the penetration of polar antibiotics. Finally, we describe how the expression and activity of certain sugar transporters are controlled in response to the availability of sugars and how the presence and uptake of sugars may affect pathogenicity and host-microbiota interactions.
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17
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Chiok KLR, Shah DH. Identification of common highly expressed genes of Salmonella Enteritidis by in silico prediction of gene expression and in vitro transcriptomic analysis. Poult Sci 2019; 98:2948-2963. [PMID: 30953073 DOI: 10.3382/ps/pez119] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/14/2018] [Accepted: 02/27/2019] [Indexed: 01/02/2023] Open
Abstract
Chickens are the reservoir host of Salmonella Enteritidis. Salmonella Enteritidis colonizes the gastro-intestinal tract of chickens and replicates within macrophages without causing clinically discernable illness. Persistence of S. Enteritidis in the hostile environments of intestinal tract and macrophages allows it to disseminate extra-intestinally to liver, spleen, and reproductive tract. Extra-intestinal dissemination into reproductive tract leads to contamination of internal contents of eggs, which is a major risk factor for human infection. Understanding the genes that contribute to S. Enteritidis persistence in the chicken host is central to elucidate the genetic basis of the unique pathobiology of this public health pathogen. The aim of this study was to identify a succinct set of genes associated with infection-relevant in vitro environments to provide a rational foundation for subsequent biologically-relevant research. We used in silico prediction of gene expression and RNA-seq technology to identify a core set of 73 S. Enteritidis genes that are consistently highly expressed in multiple S. Enteritidis strains cultured at avian physiologic temperature under conditions that represent intestinal and intracellular environments. These common highly expressed (CHX) genes encode proteins involved in bacterial metabolism, protein synthesis, cell-envelope biogenesis, stress response, and a few proteins with uncharacterized functions. Further studies are needed to dissect the contribution of these CHX genes to the pathobiology of S. Enteritidis in the avian host. Several of the CHX genes could serve as promising targets for studies towards the development of immunoprophylactic and novel therapeutic strategies to prevent colonization of chickens and their environment with S. Enteritidis.
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Affiliation(s)
- Kim Lam R Chiok
- Department of Veterinary Microbiology and Pathology, Washington State University, Pullman, WA 99164-7040
| | - Devendra H Shah
- Department of Veterinary Microbiology and Pathology, Washington State University, Pullman, WA 99164-7040
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18
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Understanding the multifaceted roles of the phosphoenolpyruvate: Phosphotransferase system in regulation of Salmonella virulence using a mutant defective in ptsI and crr expression. Microbiol Res 2019; 223-225:63-71. [PMID: 31178053 DOI: 10.1016/j.micres.2019.04.002] [Citation(s) in RCA: 15] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/08/2018] [Revised: 03/23/2019] [Accepted: 04/11/2019] [Indexed: 11/22/2022]
Abstract
The phosphoenolpyruvate (PEP):carbohydrate phosphotransferase system (PTS) catalyzes the translocation of sugar substrates with their concomitant phosphorylation in bacteria. In addition to its intrinsic role in sugar transport and metabolism, numerous recent studies report the versatility of the PTS to interconnect energy and signal transduction in response to sugar availability. In this study, the role of PTS in Salmonella virulence regulation was explored. To decipher the regulatory network coordinated by the PTS during Salmonella infection, a transcriptomic approach was applied to a transposon insertion mutant with defective expression of ptsI and crr, which encode enzyme I and enzyme IIAGlc of the PTS, respectively. There were 114 differentially expressed genes (DEGs) exhibiting two-fold or higher expression changes in the transposon mutant strain, with 13 up-regulated genes versus 101 down-regulated genes. One-third of the DEGs were associated with energy production and carbohydrate/amino acid metabolism pathways, implicating the prominent role of the PTS in carbohydrate transport. With regard to regulation of virulence, the tested mutant decreased the expression of genes associated with quorum sensing, Salmonella pathogenicity islands, flagella, and the PhoPQ regulon. We investigated the possibility of PTS-mediated regulation of virulence determinants identified in the transcriptomic analysis and proposed a regulatory circuit orchestrated by the PTS in Salmonella infection of host cells. These results suggest that Salmonella divergently controls virulence attributes in accordance with the availability of carbohydrates in the environment.
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19
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Jeckelmann JM, Erni B. Carbohydrate Transport by Group Translocation: The Bacterial Phosphoenolpyruvate: Sugar Phosphotransferase System. Subcell Biochem 2019; 92:223-274. [PMID: 31214989 DOI: 10.1007/978-3-030-18768-2_8] [Citation(s) in RCA: 27] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 06/09/2023]
Abstract
The Bacterial Phosphoenolpyruvate (PEP) : Sugar Phosphotransferase System (PTS) mediates the uptake and phosphorylation of carbohydrates, and controls the carbon- and nitrogen metabolism in response to the availability of sugars. PTS occur in eubacteria and in a few archaebacteria but not in animals and plants. All PTS comprise two cytoplasmic phosphotransferase proteins (EI and HPr) and a species-dependent, variable number of sugar-specific enzyme II complexes (IIA, IIB, IIC, IID). EI and HPr transfer phosphorylgroups from PEP to the IIA units. Cytoplasmic IIA and IIB units sequentially transfer phosphates to the sugar, which is transported by the IIC and IICIID integral membrane protein complexes. Phosphorylation by IIB and translocation by IIC(IID) are tightly coupled. The IIC(IID) sugar transporters of the PTS are in the focus of this review. There are four structurally different PTS transporter superfamilies (glucose, glucitol, ascorbate, mannose) . Crystal structures are available for transporters of two superfamilies: bcIICmal (MalT, 5IWS, 6BVG) and bcIICchb (ChbC, 3QNQ) of B. subtilis from the glucose family, and IICasc (UlaA, 4RP9, 5ZOV) of E. coli from the ascorbate superfamily . They are homodimers and each protomer has an independent transport pathway which functions by an elevator-type alternating-access mechanism. bcIICmal and bcIICchb have the same fold, IICasc has a completely different fold. Biochemical and biophysical data accumulated in the past with the transporters for mannitol (IICBAmtl) and glucose (IICBglc) are reviewed and discussed in the context of the bcIICmal crystal structures. The transporters of the mannose superfamily are dimers of protomers consisting of a IIC and a IID protein chain. The crystal structure is not known and the topology difficult to predict. Biochemical data indicate that the IICIID complex employs a different transport mechanism . Species specific IICIID serve as a gateway for the penetration of bacteriophage lambda DNA across, and insertion of class IIa bacteriocins into the inner membrane. PTS transporters are inserted into the membrane by SecYEG translocon and have specific lipid requirements. Immunoelectron- and fluorescence microscopy indicate a non-random distribution and supramolecular complexes of PTS proteins.
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Affiliation(s)
- Jean-Marc Jeckelmann
- Institute of Biochemistry and Molecular Medicine, University of Bern, Bühlstrasse 28, 3012, Bern, Switzerland.
| | - Bernhard Erni
- Institute of Biochemistry and Molecular Medicine, University of Bern, Bühlstrasse 28, 3012, Bern, Switzerland
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20
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Jiang B, You B, Tan L, Yu S, Li H, Bai G, Li S, Rao X, Xie Z, Shi X, Peng Y, Hu X. Clinical Staphylococcus argenteus Develops to Small Colony Variants to Promote Persistent Infection. Front Microbiol 2018; 9:1347. [PMID: 30013523 PMCID: PMC6036243 DOI: 10.3389/fmicb.2018.01347] [Citation(s) in RCA: 16] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/14/2018] [Accepted: 06/01/2018] [Indexed: 11/25/2022] Open
Abstract
Staphylococcus argenteus is a novel staphylococcal species (also considered as a part of Staphylococcus aureus complex) that is infrequently reported on, and clinical S. argenteus infections are largely unstudied. Here, we report a persistent and recurrent hip joint infection case in which a S. argenteus strain and its small colony variants (SCVs) strain were successively isolated. We present features of the two S. argenteus strains and case details of their pathogenicity, explore factors that induce S. argenteus SCVs formation in the course of anti-infection therapy, and reveal potential genetic mechanisms for S. argenteus SCVs formation. S. argenteus strains were identified using phenotypic and genotypic methods. The S. argenteus strain XNO62 and SCV strain XNO106 were characterized using different models. S. argenteus SCVs were induced by the administration of amikacin and by chronic infection course based on the clinical case details. The genomes of both strains were sequenced and aligned in a pair-wise fashion using Mauve. The case details gave us important insights on the characteristics and therapeutic strategies for infections caused by S. argenteus and its SCVs. We found that strain XNO62 and SCV strain XNO106 are genetically-related sequential clones, the SCV strain exhibits reduced virulence but enhanced intracellular persistence compared to strain XNO62, thus promoting persistent infection. The induction experiments for S. argenteus SCVs demonstrated that high concentrations of amikacin greatly induce S. argenteus XNO62 to form SCVs, while a chronic infection of S. argenteus XNO62 slightly induces SCVs formation. Potential genetic mechanisms for S. argenteus SCVs formation were revealed and discussed based on genomic alignments. In conclusion, we report the first case of infection caused by S. argenteus and its SCVs strain. More attention should be paid to infections caused by S. argenteus and its SCVs, as they constitute a challenge to current therapeutic strategies. The problem of S. argenteus SCVs should be noticed, in particular when amikacin is used or in the case of a chronic S. argenteus infection.
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Affiliation(s)
- Bei Jiang
- Institute of Burn Research, State Key Laboratory of Trauma, Burns and Combined Injury, Southwest Hospital, Third Military Medical University (Army Medical University), Chongqing, China
| | - Bo You
- Department of Cardiothoracic Surgery, No. 324 Hospital of People's Liberation Army, Chongqing, China
| | - Li Tan
- Department of Microbiology, College of Basic Medical Sciences, Third Military Medical University (Army Medical University), Chongqing, China
| | - Shengpeng Yu
- Department of Orthopedics, Southwest Hospital, Third Military Medical University (Army Medical University), Chongqing, China
| | - Han Li
- Cadet Brigade, Third Military Medical University (Army Medical University), Chongqing, China
| | - Guoqing Bai
- Cadet Brigade, Third Military Medical University (Army Medical University), Chongqing, China
| | - Shu Li
- Department of Microbiology, College of Basic Medical Sciences, Third Military Medical University (Army Medical University), Chongqing, China
| | - Xiancai Rao
- Department of Microbiology, College of Basic Medical Sciences, Third Military Medical University (Army Medical University), Chongqing, China
| | - Zhao Xie
- Department of Orthopedics, Southwest Hospital, Third Military Medical University (Army Medical University), Chongqing, China
| | - Xianming Shi
- MOST-USDA Joint Research Center for Food Safety, School of Agriculture and Biology, and State Key Laboratory of Microbial Metabolism, Shanghai Jiao Tong University, Shanghai, China
| | - Yizhi Peng
- Institute of Burn Research, State Key Laboratory of Trauma, Burns and Combined Injury, Southwest Hospital, Third Military Medical University (Army Medical University), Chongqing, China
| | - Xiaomei Hu
- Department of Microbiology, College of Basic Medical Sciences, Third Military Medical University (Army Medical University), Chongqing, China
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21
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Biological and regulatory roles of acid-induced small RNA RyeC in Salmonella Typhimurium. Biochimie 2018; 150:48-56. [PMID: 29730297 DOI: 10.1016/j.biochi.2018.05.001] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/05/2018] [Accepted: 05/01/2018] [Indexed: 12/23/2022]
Abstract
Salmonella Typhimurium is an enteric pathogen that has evolved masterful strategies to enable survival under stress conditions both within and outside a host. The acid tolerance response (ATR) is one such mechanism that enhances the viability of acid adapted bacteria to lethal pH levels. While numerous studies exist on the protein coding components of this response, there is very little data on the roles of small RNAs (sRNAs). These non-coding RNA molecules have recently been shown to play roles as regulators of bacterial stress response and virulence pathways. They function through complementary base pairing interactions with target mRNAs and affect their translation and/or stability. There are also a few that directly bind to proteins by mimicking their respective targets. Here, we identify several sRNAs expressed during the ATR of S. Typhimurium and characterize one highly induced candidate, RyeC. Further, we identify ptsI as a trans-encoded target that is directly regulated by this sRNA. From a functional perspective, over-expression of RyeC in Salmonella produced a general attenuation of several in vitro phenotypes including acid survival, motility, adhesion and invasion of epithelial cell lines as well as replication within macrophages. Together, this study highlights the diverse roles played by sRNAs in acid tolerance and virulence of S. Typhimurium.
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Phosphotransferase systems in Enterococcus faecalis OG1RF enhance anti-stress capacity in vitro and in vivo. Res Microbiol 2017; 168:558-566. [DOI: 10.1016/j.resmic.2017.03.003] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/16/2017] [Revised: 03/10/2017] [Accepted: 03/13/2017] [Indexed: 12/26/2022]
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Choo JM, Cheung JK, Wisniewski JA, Steer DL, Bulach DM, Hiscox TJ, Chakravorty A, Smith AI, Gell DA, Rood JI, Awad MM. The NEAT Domain-Containing Proteins of Clostridium perfringens Bind Heme. PLoS One 2016; 11:e0162981. [PMID: 27637108 PMCID: PMC5026354 DOI: 10.1371/journal.pone.0162981] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/23/2015] [Accepted: 08/31/2016] [Indexed: 12/27/2022] Open
Abstract
The ability of a pathogenic bacterium to scavenge iron from its host is important for its growth and survival during an infection. Our studies on C. perfringens gas gangrene strain JIR325, a derivative of strain 13, showed that it is capable of utilizing both human hemoglobin and ferric chloride, but not human holo-transferrin, as an iron source for in vitro growth. Analysis of the C. perfringens strain 13 genome sequence identified a putative heme acquisition system encoded by an iron-regulated surface gene region that we have named the Cht (Clostridium perfringensheme transport) locus. This locus comprises eight genes that are co-transcribed and includes genes that encode NEAT domain-containing proteins (ChtD and ChtE) and a putative sortase (Srt). The ChtD, ChtE and Srt proteins were shown to be expressed in JIR325 cells grown under iron-limited conditions and were localized to the cell envelope. Moreover, the NEAT proteins, ChtD and ChtE, were found to bind heme. Both chtDE and srt mutants were constructed, but these mutants were not defective in hemoglobin or ferric chloride utilization. They were, however, attenuated for virulence when tested in a mouse myonecrosis model, although the virulence phenotype could not be restored via complementation and, as is common with such systems, secondary mutations were identified in these strains. In summary, this study provides evidence for the functional redundancies that occur in the heme transport pathways of this life threatening pathogen.
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Affiliation(s)
- Jocelyn M. Choo
- Infection and Immunity Program, Biomedicine Discovery Institute and Department of Microbiology, Monash University, Clayton, VIC 3800, Australia
| | - Jackie K. Cheung
- Infection and Immunity Program, Biomedicine Discovery Institute and Department of Microbiology, Monash University, Clayton, VIC 3800, Australia
| | - Jessica A. Wisniewski
- Infection and Immunity Program, Biomedicine Discovery Institute and Department of Microbiology, Monash University, Clayton, VIC 3800, Australia
| | - David L. Steer
- Department of Biochemistry and Molecular Biology, Monash University, Clayton, Victoria, Australia
| | - Dieter M. Bulach
- Victorian Bioinformatics Consortium, Monash University, Clayton, Victoria, Australia
| | - Thomas J. Hiscox
- Infection and Immunity Program, Biomedicine Discovery Institute and Department of Microbiology, Monash University, Clayton, VIC 3800, Australia
| | - Anjana Chakravorty
- Infection and Immunity Program, Biomedicine Discovery Institute and Department of Microbiology, Monash University, Clayton, VIC 3800, Australia
| | - A. Ian Smith
- Victorian Bioinformatics Consortium, Monash University, Clayton, Victoria, Australia
| | - David A. Gell
- School of Medicine, University of Tasmania, Hobart, Tasmania 7000, Australia
| | - Julian I. Rood
- Infection and Immunity Program, Biomedicine Discovery Institute and Department of Microbiology, Monash University, Clayton, VIC 3800, Australia
| | - Milena M. Awad
- Infection and Immunity Program, Biomedicine Discovery Institute and Department of Microbiology, Monash University, Clayton, VIC 3800, Australia
- * E-mail:
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Lim S, Han A, Kim D, Seo HS. Transcriptional Profiling of an AttenuatedSalmonellaTyphimuriumptsIMutant Strain Under Low-oxygen Conditions using Microarray Analysis. ACTA ACUST UNITED AC 2015. [DOI: 10.4167/jbv.2015.45.3.200] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/17/2022]
Affiliation(s)
- Sangyong Lim
- Research Division for Biotechnology, Korea Atomic Energy Research Institute, Jeongeup, Korea
| | - Ahreum Han
- Research Division for Biotechnology, Korea Atomic Energy Research Institute, Jeongeup, Korea
| | - Dongho Kim
- Research Division for Biotechnology, Korea Atomic Energy Research Institute, Jeongeup, Korea
| | - Ho Seong Seo
- Research Division for Biotechnology, Korea Atomic Energy Research Institute, Jeongeup, Korea
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Allan RN, Skipp P, Jefferies J, Clarke SC, Faust SN, Hall-Stoodley L, Webb J. Pronounced metabolic changes in adaptation to biofilm growth by Streptococcus pneumoniae. PLoS One 2014; 9:e107015. [PMID: 25188255 PMCID: PMC4154835 DOI: 10.1371/journal.pone.0107015] [Citation(s) in RCA: 37] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/02/2014] [Accepted: 08/05/2014] [Indexed: 11/19/2022] Open
Abstract
Streptococcus pneumoniae accounts for a significant global burden of morbidity and mortality and biofilm development is increasingly recognised as important for colonization and infection. Analysis of protein expression patterns during biofilm development may therefore provide valuable insights to the understanding of pneumococcal persistence strategies and to improve vaccines. iTRAQ (isobaric tagging for relative and absolute quantification), a high-throughput gel-free proteomic approach which allows high resolution quantitative comparisons of protein profiles between multiple phenotypes, was used to interrogate planktonic and biofilm growth in a clinical serotype 14 strain. Comparative analyses of protein expression between log-phase planktonic and 1-day and 7-day biofilm cultures representing nascent and late phase biofilm growth were carried out. Overall, 244 proteins were identified, of which >80% were differentially expressed during biofilm development. Quantitatively and qualitatively, metabolic regulation appeared to play a central role in the adaptation from the planktonic to biofilm phenotype. Pneumococci adapted to biofilm growth by decreasing enzymes involved in the glycolytic pathway, as well as proteins involved in translation, transcription, and virulence. In contrast, proteins with a role in pyruvate, carbohydrate, and arginine metabolism were significantly increased during biofilm development. Downregulation of glycolytic and translational proteins suggests that pneumococcus adopts a covert phenotype whilst adapting to an adherent lifestyle, while utilization of alternative metabolic pathways highlights the resourcefulness of pneumococcus to facilitate survival in diverse environmental conditions. These metabolic proteins, conserved across both the planktonic and biofilm phenotypes, may also represent target candidates for future vaccine development and treatment strategies. Data are available via ProteomeXchange with identifier PXD001182.
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Affiliation(s)
- Raymond N. Allan
- Academic Unit of Clinical and Experimental Sciences, Faculty of Medicine and Institute for Life Sciences, University of Southampton, Southampton, United Kingdom
- Southampton NIHR Wellcome Trust Clinical Research Facility, University Hospital Southampton NHS Foundation Trust, Southampton, United Kingdom
- * E-mail:
| | - Paul Skipp
- Centre for Biological Sciences, University of Southampton, Southampton, United Kingdom
- Centre for Proteomic Research, Institute for Life Sciences, University of Southampton, Southampton, United Kingdom
| | - Johanna Jefferies
- Academic Unit of Clinical and Experimental Sciences, Faculty of Medicine and Institute for Life Sciences, University of Southampton, Southampton, United Kingdom
- Public Health England, Southampton, United Kingdom
| | - Stuart C. Clarke
- Academic Unit of Clinical and Experimental Sciences, Faculty of Medicine and Institute for Life Sciences, University of Southampton, Southampton, United Kingdom
- Public Health England, Southampton, United Kingdom
- Southampton NIHR Respiratory Biomedical Research Unit, University Hospital Southampton NHS Foundation Trust, Southampton, United Kingdom
| | - Saul N. Faust
- Academic Unit of Clinical and Experimental Sciences, Faculty of Medicine and Institute for Life Sciences, University of Southampton, Southampton, United Kingdom
- Southampton NIHR Wellcome Trust Clinical Research Facility, University Hospital Southampton NHS Foundation Trust, Southampton, United Kingdom
- Southampton NIHR Respiratory Biomedical Research Unit, University Hospital Southampton NHS Foundation Trust, Southampton, United Kingdom
| | - Luanne Hall-Stoodley
- Academic Unit of Clinical and Experimental Sciences, Faculty of Medicine and Institute for Life Sciences, University of Southampton, Southampton, United Kingdom
- Southampton NIHR Wellcome Trust Clinical Research Facility, University Hospital Southampton NHS Foundation Trust, Southampton, United Kingdom
- Microbial Infection and Immunity, Centre for Microbial Interface Biology, The Ohio State University, Columbus, Ohio, United States of America
| | - Jeremy Webb
- Centre for Biological Sciences, University of Southampton, Southampton, United Kingdom
- Southampton NIHR Respiratory Biomedical Research Unit, University Hospital Southampton NHS Foundation Trust, Southampton, United Kingdom
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26
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Gera K, Le T, Jamin R, Eichenbaum Z, McIver KS. The phosphoenolpyruvate phosphotransferase system in group A Streptococcus acts to reduce streptolysin S activity and lesion severity during soft tissue infection. Infect Immun 2014; 82:1192-204. [PMID: 24379283 PMCID: PMC3957985 DOI: 10.1128/iai.01271-13] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/07/2013] [Accepted: 12/19/2013] [Indexed: 11/20/2022] Open
Abstract
Obtaining essential nutrients, such as carbohydrates, is an important process for bacterial pathogens to successfully colonize host tissues. The phosphoenolpyruvate phosphotransferase system (PTS) is the primary mechanism by which bacteria transport sugars and sense the carbon state of the cell. The group A streptococcus (GAS) is a fastidious microorganism that has adapted to a variety of niches in the human body to elicit a wide array of diseases. A ΔptsI mutant (enzyme I [EI] deficient) generated in three different strains of M1T1 GAS was unable to grow on multiple carbon sources (PTS and non-PTS). Complementation with ptsI expressed under its native promoter in single copy was able to rescue the growth defect of the mutant. In a mouse model of GAS soft tissue infection, all ΔptsI mutants exhibited a significantly larger and more severe ulcerative lesion than mice infected with the wild type. Increased transcript levels of sagA and streptolysin S (SLS) activity during exponential-phase growth was observed. We hypothesized that early onset of SLS activity would correlate with the severity of the lesions induced by the ΔptsI mutant. In fact, infection of mice with a ΔptsI sagB double mutant resulted in a lesion comparable to that of either the wild type or a sagB mutant alone. Therefore, a functional PTS is not required for subcutaneous skin infection in mice; however, it does play a role in coordinating virulence factor expression and disease progression.
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Affiliation(s)
- Kanika Gera
- Department of Cell Biology & Molecular Genetics and Maryland Pathogen Research Institute, University of Maryland, College Park, Maryland, USA
| | - Tuquynh Le
- Department of Cell Biology & Molecular Genetics and Maryland Pathogen Research Institute, University of Maryland, College Park, Maryland, USA
| | - Rebecca Jamin
- Biology Department, Georgia State University, Atlanta, Georgia, USA
| | | | - Kevin S. McIver
- Department of Cell Biology & Molecular Genetics and Maryland Pathogen Research Institute, University of Maryland, College Park, Maryland, USA
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Xanthone derivatives could be potential antibiotics: virtual screening for the inhibitors of enzyme I of bacterial phosphoenolpyruvate-dependent phosphotransferase system. J Antibiot (Tokyo) 2013; 66:453-8. [PMID: 23632921 DOI: 10.1038/ja.2013.30] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/05/2012] [Revised: 03/14/2013] [Accepted: 03/21/2013] [Indexed: 12/19/2022]
Abstract
The phosphoenolpyruvate phosphotransferase system (PTS) is ubiquitous in eubacteria and absent from eukaryotes. The system consists of two phosphoryl carriers, enzyme I (EI) and the histidine-containing phosphoryl carrier protein (HPr), and several PTS transporters, catalyzing the concomitant uptake and phosphorylation of several carbohydrates. Since a deficiency of EI in bacterial mutants lead to severe growth defects, EI could be a drug target to develop antimicrobial agents. We used the 3D structure PDB 1ZYM of Escherichia coli EI as the target to virtually screen the potential tight binders from NPPEDIA (Natural Product Encyclopedia), ZINC and Super Natural databases. These databases were screened using the docking tools of Discovery Studio 2.0 and the Integrated Drug Design System IDDS. Among the many interesting hits, xanthone derivatives with reasonably high Dock scores received more attentions. Two of the xanthone derivatives were obtained to examine their capabilities to inhibit cell growth of both Gram-positive and Gram-negative bacterial strains. The results indicate that they may exert the inhibition effects by blocking the EI activities. We have demonstrated for the first time that the xanthone derivatives have high potential to be developed as future antibiotics.
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Erni B. The bacterial phosphoenolpyruvate: sugar phosphotransferase system (PTS): an interface between energy and signal transduction. JOURNAL OF THE IRANIAN CHEMICAL SOCIETY 2012. [DOI: 10.1007/s13738-012-0185-1] [Citation(s) in RCA: 24] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/24/2022]
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29
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Jang SJ, Lee YJ, Lim S, Kim KI, Lee KC, An GI, Lee TS, Cheon GJ, Lim SM, Kang JH. Imaging of a localized bacterial infection with endogenous thymidine kinase using radioisotope-labeled nucleosides. Int J Med Microbiol 2012; 302:101-7. [PMID: 22264560 DOI: 10.1016/j.ijmm.2011.11.002] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/17/2011] [Revised: 09/29/2011] [Accepted: 11/06/2011] [Indexed: 02/05/2023] Open
Abstract
The importance of noninvasive imaging methods to bacterial infections is widely recognized. To obtain bacterial infection imaging with radioisotope-labeled nucleosides, bacterial thymidine kinase (tk) activities of Salmonella typhimurium with [(125)I]5-iodo-1-(2'-fluoro-2'-deoxy-β-d-arabinofuranosyl)uracil ([(125)I]FIAU) or 3'-deoxy-3'-[(18)F]fluorothymidine ([(18)F]FLT) were measured. The infection model in BALB/c mice was imaged with [(125)I]FIAU or [(18)F]FLT using small-animal Single Photon Emission Computed Tomography (SPECT) or Positron Emission Tomography (PET), respectively. The accumulated radioactivity of [(125)I]FIAU or [(18)F]FLT in the two strains showed a linearly increased pattern with increasing incubation time or bacterial numbers. The image clearly demonstrated a high uptake of [(125)I]FIAU and [(18)F]FLT in the bacterial infection site. [(18)F]FLT uptake in the infection site of was 7.286±2.405, whereas that in the uninfected site was 0.519±0.561. The relative activity ratio of the infected region in relation to the uninfected region was 2.98 at 4h after an injection with [(125)I]FIAU determined by biodistribution data. In conclusion, the bacterial tk activity was confirmed by the cellular uptake and imaging with [(125)I]FIAU or [(18)F]FLT. Therefore, a localized bacterial infection in living mice can be monitored using radioisotope-labeled nucleosides with a nuclear medicine imaging modality.
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Affiliation(s)
- Su Jin Jang
- Molecular Imaging Research Center, Seoul, Republic of Korea
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30
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Karageorgopoulos DE, Wang R, Yu XH, Falagas ME. Fosfomycin: evaluation of the published evidence on the emergence of antimicrobial resistance in Gram-negative pathogens. J Antimicrob Chemother 2011; 67:255-68. [PMID: 22096042 DOI: 10.1093/jac/dkr466] [Citation(s) in RCA: 161] [Impact Index Per Article: 11.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/17/2023] Open
Abstract
Fosfomycin has attracted renewed interest for the treatment of lower urinary tract and even systemic infections caused by Gram-negative pathogens with resistance to traditionally used agents. The main concern regarding the clinical utility of fosfomycin refers to the potential for the emergence of resistance during therapy. In this review, we evaluate the available published evidence regarding the mechanisms and the frequency of in vitro mutational resistance to fosfomycin in Gram-negative pathogens. We also review data regarding the emergence of resistance in clinical studies of fosfomycin therapy in various infectious syndromes and data from studies that evaluate the evolution of fosfomycin resistance over time. There appears to be discordance between the high frequency of mutational resistance to fosfomycin in vitro and the lower extent of this phenomenon in clinical studies. This discordance could at least partly be attributed to a biological cost associated with common mutations that confer resistance to fosfomycin, including decreased growth rate and low adherence to epithelial cells for the resistant mutants. The development of resistance appears to be more frequent both in vitro and in clinical studies for Pseudomonas aeruginosa in comparison with Escherichia coli, whereas relevant data for other Enterobacteriaceae are relatively scarce. The urinary tract seems to provide a favourable environment for the use of fosfomycin with a low associated likelihood for the emergence of resistance, owing to high drug concentrations and acidic pH. Additional data are needed to further clarify the optimal use of fosfomycin for different infectious syndromes caused by contemporary multidrug-resistant pathogens.
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Insight into bacterial phosphotransferase system-mediated signaling by interspecies transplantation of a transcriptional regulator. J Bacteriol 2011; 193:2013-26. [PMID: 21335451 DOI: 10.1128/jb.01459-10] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
The bacterial sugar:phosphotransferase system (PTS) delivers phosphoryl groups via proteins EI and HPr to the EII sugar transporters. The antitermination protein LicT controls β-glucoside utilization in Bacillus subtilis and belongs to a family of bacterial transcriptional regulators that are antagonistically controlled by PTS-catalyzed phosphorylations at two homologous PTS regulation domains (PRDs). LicT is inhibited by phosphorylation of PRD1, which is mediated by the β-glucoside transporter EII(Bgl). Phosphorylation of PRD2 is catalyzed by HPr and stimulates LicT activity. Here, we report that LicT, when artificially expressed in the nonrelated bacterium Escherichia coli, is likewise phosphorylated at both PRDs, but the phosphoryl group donors differ. Surprisingly, E. coli HPr phosphorylates PRD1 rather than PRD2, while the stimulatory phosphorylation of PRD2 is carried out by the HPr homolog NPr. This demonstrates that subtle differences in the interaction surface of HPr can switch its affinities toward the PRDs. NPr transfers phosphoryl groups from EI(Ntr) to EIIA(Ntr). Together these proteins form the paralogous PTS(Ntr), which controls the activity of K(+) transporters in response to unknown signals. This is achieved by binding of dephosphorylated EIIA(Ntr) to other proteins. We generated LicT mutants that were controlled either negatively by HPr or positively by NPr and were suitable bio-bricks, in order to monitor or to couple gene expression to the phosphorylation states of these two proteins. With the aid of these tools, we identified the stringent starvation protein SspA as a regulator of EIIA(Ntr) phosphorylation, indicating that PTS(Ntr) represents a stress-related system in E. coli.
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Navdaeva V, Zurbriggen A, Waltersperger S, Schneider P, Oberholzer AE, Bähler P, Bächler C, Grieder A, Baumann U, Erni B. Phosphoenolpyruvate: Sugar Phosphotransferase System from the Hyperthermophilic Thermoanaerobacter tengcongensis. Biochemistry 2011; 50:1184-93. [DOI: 10.1021/bi101721f] [Citation(s) in RCA: 20] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Affiliation(s)
- Vera Navdaeva
- Departement für Chemie und Biochemie (or Department for Chemistry and Biochemistry), Universität Bern, Freiestrasse 3, CH-3012 Bern, Switzerland
| | - Andreas Zurbriggen
- Departement für Chemie und Biochemie (or Department for Chemistry and Biochemistry), Universität Bern, Freiestrasse 3, CH-3012 Bern, Switzerland
| | - Sandro Waltersperger
- Departement für Chemie und Biochemie (or Department for Chemistry and Biochemistry), Universität Bern, Freiestrasse 3, CH-3012 Bern, Switzerland
| | - Philipp Schneider
- Departement für Chemie und Biochemie (or Department for Chemistry and Biochemistry), Universität Bern, Freiestrasse 3, CH-3012 Bern, Switzerland
| | - Anselm E. Oberholzer
- Departement für Chemie und Biochemie (or Department for Chemistry and Biochemistry), Universität Bern, Freiestrasse 3, CH-3012 Bern, Switzerland
| | - Priska Bähler
- Departement für Chemie und Biochemie (or Department for Chemistry and Biochemistry), Universität Bern, Freiestrasse 3, CH-3012 Bern, Switzerland
| | - Christoph Bächler
- Departement für Chemie und Biochemie (or Department for Chemistry and Biochemistry), Universität Bern, Freiestrasse 3, CH-3012 Bern, Switzerland
| | - Andreas Grieder
- Departement für Chemie und Biochemie (or Department for Chemistry and Biochemistry), Universität Bern, Freiestrasse 3, CH-3012 Bern, Switzerland
| | - Ulrich Baumann
- Departement für Chemie und Biochemie (or Department for Chemistry and Biochemistry), Universität Bern, Freiestrasse 3, CH-3012 Bern, Switzerland
| | - Bernhard Erni
- Departement für Chemie und Biochemie (or Department for Chemistry and Biochemistry), Universität Bern, Freiestrasse 3, CH-3012 Bern, Switzerland
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Betancor L, Pereira M, Martinez A, Giossa G, Fookes M, Flores K, Barrios P, Repiso V, Vignoli R, Cordeiro N, Algorta G, Thomson N, Maskell D, Schelotto F, Chabalgoity JA. Prevalence of Salmonella enterica in poultry and eggs in Uruguay during an epidemic due to Salmonella enterica serovar Enteritidis. J Clin Microbiol 2010; 48:2413-23. [PMID: 20484605 PMCID: PMC2897505 DOI: 10.1128/jcm.02137-09] [Citation(s) in RCA: 61] [Impact Index Per Article: 4.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/02/2009] [Revised: 01/02/2010] [Accepted: 05/10/2010] [Indexed: 12/30/2022] Open
Abstract
Salmonella enterica serovar Enteritidis (S. Enteritidis) is frequently associated with food-borne disease worldwide. Poultry-derived products are a major source. An epidemic of human infection with S. Enteritidis occurred in Uruguay, and to evaluate the extent of poultry contamination, we conducted a nationwide survey over 2 years that included the analysis of sera from 5,751 birds and 12,400 eggs. Serological evidence of infection with Salmonella group O:9 was found in 24.4% of the birds. All positive sera were retested with a gm flagellum-based enzyme-linked immunosorbent assay, and based on these results, the national prevalence of S. Enteritidis infection was estimated to be 6.3%. Salmonellae were recovered from 58 of 620 pools made up of 20 eggs each, demonstrating a prevalence of at least 1 in every 214 eggs. Surprisingly, the majority of the isolates were not S. Enteritidis. Thirty-nine isolates were typed as S. Derby, 9 as S. Gallinarum, 8 as S. Enteritidis, and 2 as S. Panama. Despite the highest prevalence in eggs, S. Derby was not isolated from humans in the period of analysis, suggesting a low capacity to infect humans. Microarray-based comparative genomic hybridization analysis of S. Derby and S. Enteritidis revealed more than 350 genetic differences. S. Derby lacked pathogenicity islands 13 and 14, the fimbrial lpf operon, and other regions encoding metabolic functions. Several of these regions are present not only in serovar Enteritidis but also in all sequenced strains of S. Typhimurium, suggesting that these regions might be related to the capacity of Salmonella to cause food-borne disease.
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Affiliation(s)
- L. Betancor
- Bacteriology and Virology Department, Biotechnology Department, Instituto de Higiene, Facultad de Medicina, Universidad de la República, Montevideo, Uruguay, Department of Avian Pathology, Veterinary Faculty, Universidad de la República, Montevideo, Uruguay, DILAVE, Central Veterinary Laboratories, Ministry of Agriculture, Montevideo, Uruguay, The Wellcome Trust Sanger Institute, Wellcome Trust Genome Campus, Hinxton, Cambridge CB10 1SA, United Kingdom, Department of Veterinary Medicine, University of Cambridge, Madingley Road, Cambridge CB3 0ES, United Kingdom
| | - M. Pereira
- Bacteriology and Virology Department, Biotechnology Department, Instituto de Higiene, Facultad de Medicina, Universidad de la República, Montevideo, Uruguay, Department of Avian Pathology, Veterinary Faculty, Universidad de la República, Montevideo, Uruguay, DILAVE, Central Veterinary Laboratories, Ministry of Agriculture, Montevideo, Uruguay, The Wellcome Trust Sanger Institute, Wellcome Trust Genome Campus, Hinxton, Cambridge CB10 1SA, United Kingdom, Department of Veterinary Medicine, University of Cambridge, Madingley Road, Cambridge CB3 0ES, United Kingdom
| | - A. Martinez
- Bacteriology and Virology Department, Biotechnology Department, Instituto de Higiene, Facultad de Medicina, Universidad de la República, Montevideo, Uruguay, Department of Avian Pathology, Veterinary Faculty, Universidad de la República, Montevideo, Uruguay, DILAVE, Central Veterinary Laboratories, Ministry of Agriculture, Montevideo, Uruguay, The Wellcome Trust Sanger Institute, Wellcome Trust Genome Campus, Hinxton, Cambridge CB10 1SA, United Kingdom, Department of Veterinary Medicine, University of Cambridge, Madingley Road, Cambridge CB3 0ES, United Kingdom
| | - G. Giossa
- Bacteriology and Virology Department, Biotechnology Department, Instituto de Higiene, Facultad de Medicina, Universidad de la República, Montevideo, Uruguay, Department of Avian Pathology, Veterinary Faculty, Universidad de la República, Montevideo, Uruguay, DILAVE, Central Veterinary Laboratories, Ministry of Agriculture, Montevideo, Uruguay, The Wellcome Trust Sanger Institute, Wellcome Trust Genome Campus, Hinxton, Cambridge CB10 1SA, United Kingdom, Department of Veterinary Medicine, University of Cambridge, Madingley Road, Cambridge CB3 0ES, United Kingdom
| | - M. Fookes
- Bacteriology and Virology Department, Biotechnology Department, Instituto de Higiene, Facultad de Medicina, Universidad de la República, Montevideo, Uruguay, Department of Avian Pathology, Veterinary Faculty, Universidad de la República, Montevideo, Uruguay, DILAVE, Central Veterinary Laboratories, Ministry of Agriculture, Montevideo, Uruguay, The Wellcome Trust Sanger Institute, Wellcome Trust Genome Campus, Hinxton, Cambridge CB10 1SA, United Kingdom, Department of Veterinary Medicine, University of Cambridge, Madingley Road, Cambridge CB3 0ES, United Kingdom
| | - K. Flores
- Bacteriology and Virology Department, Biotechnology Department, Instituto de Higiene, Facultad de Medicina, Universidad de la República, Montevideo, Uruguay, Department of Avian Pathology, Veterinary Faculty, Universidad de la República, Montevideo, Uruguay, DILAVE, Central Veterinary Laboratories, Ministry of Agriculture, Montevideo, Uruguay, The Wellcome Trust Sanger Institute, Wellcome Trust Genome Campus, Hinxton, Cambridge CB10 1SA, United Kingdom, Department of Veterinary Medicine, University of Cambridge, Madingley Road, Cambridge CB3 0ES, United Kingdom
| | - P. Barrios
- Bacteriology and Virology Department, Biotechnology Department, Instituto de Higiene, Facultad de Medicina, Universidad de la República, Montevideo, Uruguay, Department of Avian Pathology, Veterinary Faculty, Universidad de la República, Montevideo, Uruguay, DILAVE, Central Veterinary Laboratories, Ministry of Agriculture, Montevideo, Uruguay, The Wellcome Trust Sanger Institute, Wellcome Trust Genome Campus, Hinxton, Cambridge CB10 1SA, United Kingdom, Department of Veterinary Medicine, University of Cambridge, Madingley Road, Cambridge CB3 0ES, United Kingdom
| | - V. Repiso
- Bacteriology and Virology Department, Biotechnology Department, Instituto de Higiene, Facultad de Medicina, Universidad de la República, Montevideo, Uruguay, Department of Avian Pathology, Veterinary Faculty, Universidad de la República, Montevideo, Uruguay, DILAVE, Central Veterinary Laboratories, Ministry of Agriculture, Montevideo, Uruguay, The Wellcome Trust Sanger Institute, Wellcome Trust Genome Campus, Hinxton, Cambridge CB10 1SA, United Kingdom, Department of Veterinary Medicine, University of Cambridge, Madingley Road, Cambridge CB3 0ES, United Kingdom
| | - R. Vignoli
- Bacteriology and Virology Department, Biotechnology Department, Instituto de Higiene, Facultad de Medicina, Universidad de la República, Montevideo, Uruguay, Department of Avian Pathology, Veterinary Faculty, Universidad de la República, Montevideo, Uruguay, DILAVE, Central Veterinary Laboratories, Ministry of Agriculture, Montevideo, Uruguay, The Wellcome Trust Sanger Institute, Wellcome Trust Genome Campus, Hinxton, Cambridge CB10 1SA, United Kingdom, Department of Veterinary Medicine, University of Cambridge, Madingley Road, Cambridge CB3 0ES, United Kingdom
| | - N. Cordeiro
- Bacteriology and Virology Department, Biotechnology Department, Instituto de Higiene, Facultad de Medicina, Universidad de la República, Montevideo, Uruguay, Department of Avian Pathology, Veterinary Faculty, Universidad de la República, Montevideo, Uruguay, DILAVE, Central Veterinary Laboratories, Ministry of Agriculture, Montevideo, Uruguay, The Wellcome Trust Sanger Institute, Wellcome Trust Genome Campus, Hinxton, Cambridge CB10 1SA, United Kingdom, Department of Veterinary Medicine, University of Cambridge, Madingley Road, Cambridge CB3 0ES, United Kingdom
| | - G. Algorta
- Bacteriology and Virology Department, Biotechnology Department, Instituto de Higiene, Facultad de Medicina, Universidad de la República, Montevideo, Uruguay, Department of Avian Pathology, Veterinary Faculty, Universidad de la República, Montevideo, Uruguay, DILAVE, Central Veterinary Laboratories, Ministry of Agriculture, Montevideo, Uruguay, The Wellcome Trust Sanger Institute, Wellcome Trust Genome Campus, Hinxton, Cambridge CB10 1SA, United Kingdom, Department of Veterinary Medicine, University of Cambridge, Madingley Road, Cambridge CB3 0ES, United Kingdom
| | - N. Thomson
- Bacteriology and Virology Department, Biotechnology Department, Instituto de Higiene, Facultad de Medicina, Universidad de la República, Montevideo, Uruguay, Department of Avian Pathology, Veterinary Faculty, Universidad de la República, Montevideo, Uruguay, DILAVE, Central Veterinary Laboratories, Ministry of Agriculture, Montevideo, Uruguay, The Wellcome Trust Sanger Institute, Wellcome Trust Genome Campus, Hinxton, Cambridge CB10 1SA, United Kingdom, Department of Veterinary Medicine, University of Cambridge, Madingley Road, Cambridge CB3 0ES, United Kingdom
| | - D. Maskell
- Bacteriology and Virology Department, Biotechnology Department, Instituto de Higiene, Facultad de Medicina, Universidad de la República, Montevideo, Uruguay, Department of Avian Pathology, Veterinary Faculty, Universidad de la República, Montevideo, Uruguay, DILAVE, Central Veterinary Laboratories, Ministry of Agriculture, Montevideo, Uruguay, The Wellcome Trust Sanger Institute, Wellcome Trust Genome Campus, Hinxton, Cambridge CB10 1SA, United Kingdom, Department of Veterinary Medicine, University of Cambridge, Madingley Road, Cambridge CB3 0ES, United Kingdom
| | - F. Schelotto
- Bacteriology and Virology Department, Biotechnology Department, Instituto de Higiene, Facultad de Medicina, Universidad de la República, Montevideo, Uruguay, Department of Avian Pathology, Veterinary Faculty, Universidad de la República, Montevideo, Uruguay, DILAVE, Central Veterinary Laboratories, Ministry of Agriculture, Montevideo, Uruguay, The Wellcome Trust Sanger Institute, Wellcome Trust Genome Campus, Hinxton, Cambridge CB10 1SA, United Kingdom, Department of Veterinary Medicine, University of Cambridge, Madingley Road, Cambridge CB3 0ES, United Kingdom
| | - J. A. Chabalgoity
- Bacteriology and Virology Department, Biotechnology Department, Instituto de Higiene, Facultad de Medicina, Universidad de la República, Montevideo, Uruguay, Department of Avian Pathology, Veterinary Faculty, Universidad de la República, Montevideo, Uruguay, DILAVE, Central Veterinary Laboratories, Ministry of Agriculture, Montevideo, Uruguay, The Wellcome Trust Sanger Institute, Wellcome Trust Genome Campus, Hinxton, Cambridge CB10 1SA, United Kingdom, Department of Veterinary Medicine, University of Cambridge, Madingley Road, Cambridge CB3 0ES, United Kingdom
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Böttcher T, Sieber SA. Showdomycin as a Versatile Chemical Tool for the Detection of Pathogenesis-Associated Enzymes in Bacteria. J Am Chem Soc 2010; 132:6964-72. [DOI: 10.1021/ja909150y] [Citation(s) in RCA: 67] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Affiliation(s)
- Thomas Böttcher
- Center for Integrated Protein Science Munich (CIPSM), Department of Chemistry and Biochemistry, Ludwig-Maximilians-Universität München, Butenandtstrasse 5-13, 81377 Munich, Germany
| | - Stephan A. Sieber
- Center for Integrated Protein Science Munich (CIPSM), Department of Chemistry and Biochemistry, Ludwig-Maximilians-Universität München, Butenandtstrasse 5-13, 81377 Munich, Germany
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Vibrio cholerae phosphoenolpyruvate phosphotransferase system control of carbohydrate transport, biofilm formation, and colonization of the germfree mouse intestine. Infect Immun 2010; 78:1482-94. [PMID: 20123708 DOI: 10.1128/iai.01356-09] [Citation(s) in RCA: 69] [Impact Index Per Article: 4.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/31/2022] Open
Abstract
The bacterial phosphoenolpyruvate phosphotransferase system (PTS) is a highly conserved phosphotransfer cascade whose components modulate many cellular functions in response to carbohydrate availability. Here, we further elucidate PTS control of Vibrio cholerae carbohydrate transport and activation of biofilm formation on abiotic surfaces. We then define the role of the PTS in V. cholerae colonization of the adult germfree mouse intestine. We report that V. cholerae colonizes both the small and large intestines of the mouse in a distribution that does not change over the course of a month-long experiment. Because V. cholerae possesses many PTS-independent carbohydrate transporters, the PTS is not essential for bacterial growth in vitro. However, we find that the PTS is essential for colonization of the germfree adult mouse intestine and that this requirement is independent of PTS regulation of biofilm formation. Therefore, competition for PTS substrates may be a dominant force in the success of V. cholerae as an intestinal pathogen. Because the PTS plays a role in colonization of environmental surfaces and the mammalian intestine, we propose that it may be essential to successful transit of V. cholerae through its life cycle of pathogenesis and environmental persistence.
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Bottlenecks and Hubs in Inferred Networks Are Important for Virulence in Salmonella typhimurium. J Comput Biol 2009; 16:169-80. [DOI: 10.1089/cmb.2008.04tt] [Citation(s) in RCA: 50] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/13/2022] Open
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Poultry-associated Salmonella enterica subsp. enterica serovar 4,12:d:- reveals high clonality and a distinct pathogenicity gene repertoire. Appl Environ Microbiol 2008; 75:1011-20. [PMID: 19114530 DOI: 10.1128/aem.02187-08] [Citation(s) in RCA: 36] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/30/2022] Open
Abstract
A European baseline survey during the years 2005 and 2006 has revealed that the monophasic Salmonella enterica subsp. enterica serovar 4,12:d:- was, with a prevalence of 23.6%, the most frequently isolated serovar in German broiler flocks. In Denmark and the United Kingdom, its serovar prevalences were 15.15% and 2.8%, respectively. Although poultry is a major source of human salmonellosis, serovar 4,12:d:- is rarely isolated in humans (approximately 0.09% per year). Molecular typing studies using pulsed-field gel electrophoresis and DNA microarray analysis show that the serovar is highly clonal and lacks genes with known contributions to pathogenicity. In contrast to other poultry-associated serovars, all strains were susceptible to 17 antimicrobial agents tested and did not encode any resistance determinant. Furthermore, serovar 4,12:d:- lacked the genes involved in galactonate metabolism and in the glycolysis and glyconeogenesis important for energy production in the cells. The conclusion of the study is that serovar 4,12:d:- seems to be primarily adapted to broilers and therefore causes only rare infections in humans.
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Seggewiss J, Becker K, Kotte O, Eisenacher M, Yazdi MRK, Fischer A, McNamara P, Al Laham N, Proctor R, Peters G, Heinemann M, von Eiff C. Reporter metabolite analysis of transcriptional profiles of a Staphylococcus aureus strain with normal phenotype and its isogenic hemB mutant displaying the small-colony-variant phenotype. J Bacteriol 2006; 188:7765-77. [PMID: 16980462 PMCID: PMC1636313 DOI: 10.1128/jb.00774-06] [Citation(s) in RCA: 74] [Impact Index Per Article: 3.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/06/2023] Open
Abstract
In this study, full-genome DNA microarrays based on the sequence of Staphylococcus aureus N315 were used to compare the transcriptome of a clinical S. aureus strain with a normal phenotype to that of its isogenic mutant with a stable small-colony-variant (SCV) phenotype (hemB::ermB). In addition to standard statistical analyses, systems biology advances were applied to identify reporter metabolites and to achieve a more detailed survey of genome-wide expression differences between the hemB mutant and its parental strain. Genes of enzymes involved in glycolytic and fermentative pathways were found to be up-regulated in the hemB mutant. Furthermore, our analyses allowed identification of additional differences between the normal-phenotype S. aureus and the SCV, most of which were related to metabolism. Profound differences were identified especially in purine biosynthesis as well as in arginine and proline metabolism. Of particular interest, a hypothetical gene of the Crp/Fnr family (SA2424) that is part of the arginine-deiminase (AD) pathway, whose homologue in Streptococcus suis is assumed to be involved in intracellular persistence, showed significantly increased transcription in the hemB mutant. The hemB mutant potentially uses the up-regulated AD pathway to produce ATP or (through ammonia production) to counteract the acidic environment that prevails intracellularly. Moreover, genes involved in capsular polysaccharide and cell wall synthesis were found to be significantly up-regulated in the hemB mutant and therefore potentially responsible for the changed cell morphology of SCVs. In conclusion, the identified differences may be responsible for the SCV phenotype and its association with chronic and persistent infections.
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Affiliation(s)
- Jochen Seggewiss
- Institute of Medical Microbiology, University Hospital of Münster, Domagkstrasse 10, 48149 Münster, Germany
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Tchawa Yimga M, Leatham MP, Allen JH, Laux DC, Conway T, Cohen PS. Role of gluconeogenesis and the tricarboxylic acid cycle in the virulence of Salmonella enterica serovar Typhimurium in BALB/c mice. Infect Immun 2006; 74:1130-40. [PMID: 16428761 PMCID: PMC1360343 DOI: 10.1128/iai.74.2.1130-1140.2006] [Citation(s) in RCA: 104] [Impact Index Per Article: 5.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
In Salmonella enterica serovar Typhimurium, the Cra protein (catabolite repressor/activator) regulates utilization of gluconeogenic carbon sources by activating transcription of genes in the gluconeogenic pathway, the glyoxylate bypass, the tricarboxylic acid (TCA) cycle, and electron transport and repressing genes encoding glycolytic enzymes. A serovar Typhimurium SR-11 Deltacra mutant was recently reported to be avirulent in BALB/c mice via the peroral route, suggesting that gluconeogenesis may be required for virulence. In the present study, specific SR-11 genes in the gluconeogenic pathway were deleted (fbp, glpX, ppsA, and pckA), and the mutants were tested for virulence in BALB/c mice. The data show that SR-11 does not require gluconeogenesis to retain full virulence and suggest that as yet unidentified sugars are utilized by SR-11 for growth during infection of BALB/c mice. The data also suggest that the TCA cycle operates as a full cycle, i.e., a sucCD mutant, which prevents the conversion of succinyl coenzyme A to succinate, and an DeltasdhCDA mutant, which blocks the conversion of succinate to fumarate, were both attenuated, whereas both an SR-11 DeltaaspA mutant and an SR-11 DeltafrdABC mutant, deficient in the ability to run the reductive branch of the TCA cycle, were fully virulent. Moreover, although it appears that SR-11 replenishes TCA cycle intermediates from substrates present in mouse tissues, fatty acid degradation and the glyoxylate bypass are not required, since an SR-11 DeltafadD mutant and an SR-11 DeltaaceA mutant were both fully virulent.
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Affiliation(s)
- Merlin Tchawa Yimga
- Department of Cell and Molecular Biology, University of Rhode Island, Kingston, RI 02881.
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Baltes N, Gerlach GF. Identification of genes transcribed by Actinobacillus pleuropneumoniae in necrotic porcine lung tissue by using selective capture of transcribed sequences. Infect Immun 2004; 72:6711-6. [PMID: 15501809 PMCID: PMC523062 DOI: 10.1128/iai.72.11.6711-6716.2004] [Citation(s) in RCA: 36] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/18/2022] Open
Abstract
Genes expressed by Actinobacillus pleuropneumoniae in necrotic porcine lung tissue were identified by selective capture of transcribed sequences analysis. In total, 46 genes were identified, 20 of which have been previously reported to be associated with in vivo expression or virulence in A. pleuropneumoniae or in other organisms.
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Affiliation(s)
- Nina Baltes
- Department of Infectious Diseases, Institute for Microbiology, University of Veterinary Medicine Hannover, Germany.
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