1
|
Brumwell A, Sutton G, Lantos PM, Hoffman K, Ruffin F, Brinkac L, Clarke TH, Adams MD, Fowler VG, Fouts DE, Thaden JT. Escherichia coli ST131 Associated with Increased Mortality in Bloodstream Infections from Urinary Tract Source. J Clin Microbiol 2023; 61:e0019923. [PMID: 37338371 PMCID: PMC10358158 DOI: 10.1128/jcm.00199-23] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/11/2023] [Accepted: 05/18/2023] [Indexed: 06/21/2023] Open
Abstract
Escherichia coli sequence type 131 (ST131) is a globally dominant multidrug-resistant clone, although its clinical impact on patients with bloodstream infection (BSI) is incompletely understood. This study aims to further define the risk factors, clinical outcomes, and bacterial genetics associated with ST131 BSI. A prospectively enrolled cohort study of adult inpatients with E. coli BSI was conducted from 2002 to 2015. Whole-genome sequencing was performed with the E. coli isolates. Of the 227 patients with E. coli BSI in this study, 88 (39%) were infected with ST131. Patients with E. coli ST131 BSI and those with non-ST131 BSI did not differ with respect to in-hospital mortality (17/82 [20%] versus 26/145 [18%]; P = 0.73). However, in patients with BSI from a urinary tract source, ST131 was associated with a numerically higher in-hospital mortality than patients with non-ST131 BSI (8/42 [19%] versus 4/63 [6%]; P = 0.06) and increased mortality in an adjusted analysis (odds ratio of 5.85; 95% confidence interval of 1.44 to 29.49; P = 0.02). Genomic analyses showed that ST131 isolates primarily had an H4:O25 serotype, had a higher number of prophages, and were associated with 11 flexible genomic islands as well as virulence genes involved in adhesion (papA, kpsM, yfcV, and iha), iron acquisition (iucC and iutA), and toxin production (usp and sat). In patients with E. coli BSI from a urinary tract source, ST131 was associated with increased mortality in an adjusted analysis and contained a distinct repertoire of genes influencing pathogenesis. These genes could contribute to the higher mortality observed in patients with ST131 BSI.
Collapse
Affiliation(s)
- Amanda Brumwell
- Division of Infectious Diseases, Department of Medicine, Duke University School of Medicine, Durham, North Carolina, USA
| | - Granger Sutton
- J. Craig Venter Institute, Rockville, Maryland, USA
- Noblis, Inc., Washington, DC, USA
| | - Paul M. Lantos
- Division of Infectious Diseases, Department of Medicine, Duke University School of Medicine, Durham, North Carolina, USA
- Department of Pediatrics, Duke University School of Medicine, Durham, North Carolina, USA
| | - Kate Hoffman
- Nicholas School of the Environment, Duke University, Durham, North Carolina, USA
| | - Felicia Ruffin
- Division of Infectious Diseases, Department of Medicine, Duke University School of Medicine, Durham, North Carolina, USA
| | | | | | - Mark D. Adams
- J. Craig Venter Institute, Rockville, Maryland, USA
- The Jackson Laboratory for Genomic Medicine, Farmington, Connecticut, USA
| | - Vance G. Fowler
- Division of Infectious Diseases, Department of Medicine, Duke University School of Medicine, Durham, North Carolina, USA
- Clinical Research Institute, Durham, North Carolina, USA
| | | | - Joshua T. Thaden
- Division of Infectious Diseases, Department of Medicine, Duke University School of Medicine, Durham, North Carolina, USA
| |
Collapse
|
2
|
Ferreira JL, Coleman I, Addison ML, Zachs T, Quigley BL, Wuichet K, Beeby M. The "Jack-of-all-Trades" Flagellum From Salmonella and E. coli Was Horizontally Acquired From an Ancestral β-Proteobacterium. Front Microbiol 2021; 12:643180. [PMID: 33859630 PMCID: PMC8042155 DOI: 10.3389/fmicb.2021.643180] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/17/2020] [Accepted: 03/05/2021] [Indexed: 11/24/2022] Open
Abstract
The γ-proteobacteria are a group of diverse bacteria including pathogenic Escherichia, Salmonella, Vibrio, and Pseudomonas species. The majority swim in liquids with polar, sodium-driven flagella and swarm on surfaces with lateral, non-chemotactic flagella. Notable exceptions are the enteric Enterobacteriaceae such as Salmonella and E. coli. Many of the well-studied Enterobacteriaceae are gut bacteria that both swim and swarm with the same proton-driven peritrichous flagella. How different flagella evolved in closely related lineages, however, has remained unclear. Here, we describe our phylogenetic finding that Enterobacteriaceae flagella are not native polar or lateral γ-proteobacterial flagella but were horizontally acquired from an ancestral β-proteobacterium. Using electron cryo-tomography and subtomogram averaging, we confirmed that Enterobacteriaceae flagellar motors resemble contemporary β-proteobacterial motors and are distinct to the polar and lateral motors of other γ-proteobacteria. Structural comparisons support a model in which γ-proteobacterial motors have specialized, suggesting that acquisition of a β-proteobacterial flagellum may have been beneficial as a general-purpose motor suitable for adjusting to diverse conditions. This acquisition may have played a role in the development of the enteric lifestyle.
Collapse
Affiliation(s)
- Josie L Ferreira
- Department of Life Sciences, Imperial College London, London, United Kingdom
| | - Izaak Coleman
- Department of Life Sciences, Imperial College London, London, United Kingdom
| | - Max L Addison
- Department of Life Sciences, Imperial College London, London, United Kingdom
| | - Tobias Zachs
- Department of Life Sciences, Imperial College London, London, United Kingdom
| | - Bonnie L Quigley
- Department of Life Sciences, Imperial College London, London, United Kingdom
| | - Kristin Wuichet
- Department of Biomedical Informatics, Vanderbilt University Medical Center, Nashville, TN, United States
| | - Morgan Beeby
- Department of Life Sciences, Imperial College London, London, United Kingdom
| |
Collapse
|
3
|
Ageorges V, Monteiro R, Leroy S, Burgess CM, Pizza M, Chaucheyras-Durand F, Desvaux M. Molecular determinants of surface colonisation in diarrhoeagenic Escherichia coli (DEC): from bacterial adhesion to biofilm formation. FEMS Microbiol Rev 2021; 44:314-350. [PMID: 32239203 DOI: 10.1093/femsre/fuaa008] [Citation(s) in RCA: 27] [Impact Index Per Article: 9.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/15/2019] [Accepted: 03/31/2020] [Indexed: 12/11/2022] Open
Abstract
Escherichia coli is primarily known as a commensal colonising the gastrointestinal tract of infants very early in life but some strains being responsible for diarrhoea, which can be especially severe in young children. Intestinal pathogenic E. coli include six pathotypes of diarrhoeagenic E. coli (DEC), namely, the (i) enterotoxigenic E. coli, (ii) enteroaggregative E. coli, (iii) enteropathogenic E. coli, (iv) enterohemorragic E. coli, (v) enteroinvasive E. coli and (vi) diffusely adherent E. coli. Prior to human infection, DEC can be found in natural environments, animal reservoirs, food processing environments and contaminated food matrices. From an ecophysiological point of view, DEC thus deal with very different biotopes and biocoenoses all along the food chain. In this context, this review focuses on the wide range of surface molecular determinants acting as surface colonisation factors (SCFs) in DEC. In the first instance, SCFs can be broadly discriminated into (i) extracellular polysaccharides, (ii) extracellular DNA and (iii) surface proteins. Surface proteins constitute the most diverse group of SCFs broadly discriminated into (i) monomeric SCFs, such as autotransporter (AT) adhesins, inverted ATs, heat-resistant agglutinins or some moonlighting proteins, (ii) oligomeric SCFs, namely, the trimeric ATs and (iii) supramolecular SCFs, including flagella and numerous pili, e.g. the injectisome, type 4 pili, curli chaperone-usher pili or conjugative pili. This review also details the gene regulatory network of these numerous SCFs at the various stages as it occurs from pre-transcriptional to post-translocational levels, which remains to be fully elucidated in many cases.
Collapse
Affiliation(s)
- Valentin Ageorges
- Université Clermont Auvergne, INRAE, MEDiS, F-63000 Clermont-Ferrand, France
| | - Ricardo Monteiro
- Université Clermont Auvergne, INRAE, MEDiS, F-63000 Clermont-Ferrand, France.,GSK, Via Fiorentina 1, 53100 Siena, Italy
| | - Sabine Leroy
- Université Clermont Auvergne, INRAE, MEDiS, F-63000 Clermont-Ferrand, France
| | - Catherine M Burgess
- Food Safety Department, Teagasc Food Research Centre, Ashtown, Dublin 15, Ireland
| | | | - Frédérique Chaucheyras-Durand
- Université Clermont Auvergne, INRAE, MEDiS, F-63000 Clermont-Ferrand, France.,Lallemand Animal Nutrition SAS, F-31702 Blagnac Cedex, France
| | - Mickaël Desvaux
- Université Clermont Auvergne, INRAE, MEDiS, F-63000 Clermont-Ferrand, France
| |
Collapse
|
4
|
Ranjith K, Sharma S, Shivaji S. Microbes of the human eye: Microbiome, antimicrobial resistance and biofilm formation. Exp Eye Res 2021; 205:108476. [PMID: 33549582 DOI: 10.1016/j.exer.2021.108476] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/12/2020] [Revised: 01/19/2021] [Accepted: 01/22/2021] [Indexed: 01/21/2023]
Abstract
BACKGROUND The review focuses on the bacteria associated with the human eye using the dual approach of detecting cultivable bacteria and the total microbiome using next generation sequencing. The purpose of this review was to highlight the connection between antimicrobial resistance and biofilm formation in ocular bacteria. METHODS Pubmed was used as the source to catalogue culturable bacteria and ocular microbiomes associated with the normal eyes and those with ocular diseases, to ascertain the emergence of anti-microbial resistance with special reference to biofilm formation. RESULTS This review highlights the genetic strategies used by microorganisms to evade the lethal effects of anti-microbial agents by tracing the connections between candidate genes and biofilm formation. CONCLUSION The eye has its own microbiome which needs to be extensively studied under different physiological conditions; data on eye microbiomes of people from different ethnicities, geographical regions etc. are also needed to understand how these microbiomes affect ocular health.
Collapse
Affiliation(s)
- Konduri Ranjith
- Jhaveri Microbiology Centre, Brien Holden Eye Research Centre, L. V. Prasad Eye Institute, Kallam Anji Reddy Campus, Hyderabad, Telangana, India.
| | - Savitri Sharma
- Jhaveri Microbiology Centre, Brien Holden Eye Research Centre, L. V. Prasad Eye Institute, Kallam Anji Reddy Campus, Hyderabad, Telangana, India.
| | - Sisinthy Shivaji
- Jhaveri Microbiology Centre, Brien Holden Eye Research Centre, L. V. Prasad Eye Institute, Kallam Anji Reddy Campus, Hyderabad, Telangana, India.
| |
Collapse
|
5
|
De Maayer P, Pillay T, Coutinho TA. Flagella by numbers: comparative genomic analysis of the supernumerary flagellar systems among the Enterobacterales. BMC Genomics 2020; 21:670. [PMID: 32993503 PMCID: PMC7526173 DOI: 10.1186/s12864-020-07085-w] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/24/2020] [Accepted: 09/21/2020] [Indexed: 01/17/2023] Open
Abstract
Background Flagellar motility is an efficient means of movement that allows bacteria to successfully colonize and compete with other microorganisms within their respective environments. The production and functioning of flagella is highly energy intensive and therefore flagellar motility is a tightly regulated process. Despite this, some bacteria have been observed to possess multiple flagellar systems which allow distinct forms of motility. Results Comparative genomic analyses showed that, in addition to the previously identified primary peritrichous (flag-1) and secondary, lateral (flag-2) flagellar loci, three novel types of flagellar loci, varying in both gene content and gene order, are encoded on the genomes of members of the order Enterobacterales. The flag-3 and flag-4 loci encode predicted peritrichous flagellar systems while the flag-5 locus encodes a polar flagellum. In total, 798/4028 (~ 20%) of the studied taxa incorporate dual flagellar systems, while nineteen taxa incorporate three distinct flagellar loci. Phylogenetic analyses indicate the complex evolutionary histories of the flagellar systems among the Enterobacterales. Conclusions Supernumerary flagellar loci are relatively common features across a broad taxonomic spectrum in the order Enterobacterales. Here, we report the occurrence of five (flag-1 to flag-5) flagellar loci on the genomes of enterobacterial taxa, as well as the occurrence of three flagellar systems in select members of the Enterobacterales. Considering the energetic burden of maintaining and operating multiple flagellar systems, they are likely to play a role in the ecological success of members of this family and we postulate on their potential biological functions.
Collapse
Affiliation(s)
- Pieter De Maayer
- School of Molecular & Cell Biology, University of the Witwatersrand, Wits, 2050, South Africa.
| | - Talia Pillay
- School of Molecular & Cell Biology, University of the Witwatersrand, Wits, 2050, South Africa
| | - Teresa A Coutinho
- Centre for Microbial Ecology and Genomics, University of Pretoria, Pretoria, 0002, South Africa
| |
Collapse
|
6
|
The evolutionary puzzle of Escherichia coli ST131. INFECTION GENETICS AND EVOLUTION 2020; 81:104265. [PMID: 32112974 DOI: 10.1016/j.meegid.2020.104265] [Citation(s) in RCA: 46] [Impact Index Per Article: 11.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/09/2019] [Revised: 02/22/2020] [Accepted: 02/26/2020] [Indexed: 01/02/2023]
Abstract
The abrupt expansion of Escherichia coli sequence type (ST) 131 is unmatched among Gram negative bacteria. In many ways, ST131 can be considered a real-world model for the complexities involved in the evolution of a multidrug resistant pathogen. While much progress has been made on our insights into the organism's population structure, pathogenicity and drug resistance profile, significant gaps in our knowledge remain. Whole genome studies have shed light on key mutations and genes that have been selected against the background of antibiotics, but in most cases such events are inferred and not supported by experimental data. Notable examples include the unknown fitness contribution made by specific plasmids, genomic islands and compensatory mutations. Furthermore, questions remain like why this organism in particular achieved such considerable success in such a short time span, compared to other more pathogenic and resistant clones. Herein, we document what is known regarding the genetics of this organism since its first description in 2008, but also highlight where work remains to be done for a truly comprehensive understanding of the biology of ST131, in order to account for its dramatic rise to prominence.
Collapse
|
7
|
Abstract
Bacterial and archaeal flagellins are remarkable in having a shared region with variation in housekeeping proteins and a region with extreme diversity, perhaps greater than for any other protein. Analysis of the 113,285 available full-gene sequences of flagellin genes from published bacterial and archaeal sequences revealed the nature and enormous extent of flagellin diversity. There were 35,898 unique amino acid sequences that were resolved into 187 clusters. Analysis of the Escherichia coli and Salmonella enterica flagellins revealed that the variation occurs at two levels. The first is the division of the variable regions into sequence forms that are so divergent that there is no meaningful alignment even within species, and these corresponded to the E. coli or S. enterica H-antigen groups. The second level is variation within these groups, which is extensive in both species. Shared sequence would allow PCR of the variable regions and thus strain-level analysis of microbiome DNA. Flagellin, the agent of prokaryotic flagellar motion, is very widely distributed and is the H antigen of serology. Flagellin molecules have a variable region that confers serotype specificity, encoded by the middle of the gene, and also conserved regions encoded by the two ends of the gene. We collected all available prokaryotic flagellin protein sequences and found the variable region diversity to be at two levels. In each species investigated, there are hypervariable region (HVR) forms without detectable homology in protein sequences between them. There is also considerable variation within HVR forms, indicating that some have been diverging for thousands of years and that interphylum horizontal gene transfers make a major contribution to the evolution of such atypical diversity. IMPORTANCE Bacterial and archaeal flagellins are remarkable in having a shared region with variation in housekeeping proteins and a region with extreme diversity, perhaps greater than for any other protein. Analysis of the 113,285 available full-gene sequences of flagellin genes from published bacterial and archaeal sequences revealed the nature and enormous extent of flagellin diversity. There were 35,898 unique amino acid sequences that were resolved into 187 clusters. Analysis of the Escherichia coli and Salmonella enterica flagellins revealed that the variation occurs at two levels. The first is the division of the variable regions into sequence forms that are so divergent that there is no meaningful alignment even within species, and these corresponded to the E. coli or S. enterica H-antigen groups. The second level is variation within these groups, which is extensive in both species. Shared sequence would allow PCR of the variable regions and thus strain-level analysis of microbiome DNA.
Collapse
|
8
|
De Maayer P, Pillay T, Coutinho TA. Comparative genomic analysis of the secondary flagellar (flag-2) system in the order Enterobacterales. BMC Genomics 2020; 21:100. [PMID: 32000682 PMCID: PMC6993521 DOI: 10.1186/s12864-020-6529-9] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/23/2019] [Accepted: 01/22/2020] [Indexed: 01/24/2023] Open
Abstract
Background The order Enterobacterales encompasses a broad range of metabolically and ecologically versatile bacterial taxa, most of which are motile by means of peritrichous flagella. Flagellar biosynthesis has been linked to a primary flagella locus, flag-1, encompassing ~ 50 genes. A discrete locus, flag-2, encoding a distinct flagellar system, has been observed in a limited number of enterobacterial taxa, but its function remains largely uncharacterized. Results Comparative genomic analyses showed that orthologous flag-2 loci are present in 592/4028 taxa belonging to 5/8 and 31/76 families and genera, respectively, in the order Enterobacterales. Furthermore, the presence of only the outermost flag-2 genes in many taxa suggests that this locus was far more prevalent and has subsequently been lost through gene deletion events. The flag-2 loci range in size from ~ 3.4 to 81.1 kilobases and code for between five and 102 distinct proteins. The discrepancy in size and protein number can be attributed to the presence of cargo gene islands within the loci. Evolutionary analyses revealed a complex evolutionary history for the flag-2 loci, representing ancestral elements in some taxa, while showing evidence of recent horizontal acquisition in other enterobacteria. Conclusions The flag-2 flagellar system is a fairly common, but highly variable feature among members of the Enterobacterales. Given the energetic burden of flagellar biosynthesis and functioning, the prevalence of a second flagellar system suggests it plays important biological roles in the enterobacteria and we postulate on its potential role as locomotory organ or as secretion system.
Collapse
Affiliation(s)
- Pieter De Maayer
- School of Molecular & Cell Biology, University of the Witwatersrand, 2050 Wits, Johannesburg, South Africa.
| | - Talia Pillay
- School of Molecular & Cell Biology, University of the Witwatersrand, 2050 Wits, Johannesburg, South Africa
| | - Teresa A Coutinho
- Centre for Microbial Ecology and Genomics, University of Pretoria 0002, Pretoria, South Africa
| |
Collapse
|
9
|
Protein interactome analysis of iduronic acid-containing glycosaminoglycans reveals a novel flagellar invasion factor MbhA. J Proteomics 2019; 208:103485. [PMID: 31421271 DOI: 10.1016/j.jprot.2019.103485] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/15/2019] [Revised: 08/02/2019] [Accepted: 08/12/2019] [Indexed: 12/27/2022]
Abstract
Pathogens are able to exploit specific glycosaminoglycans (GAGs), especially iduronic acid (IdoA)-containing GAGs, to invade the host. By analyzing Escherichia coli proteome chip data, we identified the interactomes of three IdoA-containing GAGs: heparin, heparin sulfate (HS), and chondroitin sulfate B (CSB). Using non-IdoA-containing GAG, chondroitin sulfate C, as a negative control, 157 proteins specifically binding with IdoA-containing GAGs were revealed in the present study. These proteins showed functional enrichment in protein synthesis and metabolism. Fifteen proteins which commonly interacts with three IdoA-containing GAGs were further examined. The regular expression for motif showed these common IdoA interactome shared a conserved sequence. Among them, we identified a second flagellar system outer membrane protein, MbhA. The MbhA has Kd values of 8.9 × 10-8 M, 5.3 × 10-7 M, and 1.79 × 10-7 M to interact with heparin, HS, and CSB, respectively. Using flow cytometry, we confirmed that the MbhA protein can bind to human epithelial cells HCT-8. Overexpression of mbhA increased the percentage of invasion in E. coli which lacks a second flagellar system. Moreover, pre-blocking of HCT-8 cells with MbhA inhibited the bacterial invasion, implying the importance of the direct interaction of MbhA and the host cell surface on bacterial invasion. SIGNIFICANCE: We analyzed the Escherichia coli proteomic data to elucidate the interactomes of three different IdoA-containing GAGs (heparin, HS, and CSB) because these IdoA-containing GAGs can mediate bacterial invasion to the host. Through proteomic and systematic analysis, a second flagellar system outer membrane protein, MbhA, was also identified in the present study. Affinity assay confirmed that MbhA can bind to three IdoA-containing GAGs heparin, HS, and CSB. The result of flow cytometry also showed MbhA can interact with human epithelial cells HCT-8. Results of bacteria invasion assay showed overexpression of mbhA promoted the bacterial invasion. Moreover, pre-blocking of HCT-8 cells with MbhA also reduced the percentage of bacterial invasion. These findings correspond well that MbhA is one of invasion factors.
Collapse
|
10
|
Ranjith K, Ramchiary J, Prakash JSS, Arunasri K, Sharma S, Shivaji S. Gene Targets in Ocular Pathogenic Escherichia coli for Mitigation of Biofilm Formation to Overcome Antibiotic Resistance. Front Microbiol 2019; 10:1308. [PMID: 31293528 PMCID: PMC6598151 DOI: 10.3389/fmicb.2019.01308] [Citation(s) in RCA: 13] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/24/2018] [Accepted: 05/27/2019] [Indexed: 11/13/2022] Open
Abstract
The present work is an attempt to establish the functionality of genes involved in biofilm formation and antibiotic resistance in an ocular strain of Escherichia coli (L-1216/2010) which was isolated and characterized from the Vitreous fluid of a patient with Endophthalmitis. For this purpose, seven separate gene-specific knockout mutants were generated by homologous recombination in ocular E. coli. The genes that were mutated included three transmembrane genes ytfR (ABC transporter ATP-binding protein), mdtO (multidrug efflux system) and tolA (inner membrane protein), ryfA coding for non-coding RNA and three metabolic genes mhpA (3-3-hydroxyphenylpropionate 1,2-dioxygenase), mhpB (2,3-di hydroxyphenylpropionate 1,2-dioxygenase), and bdcR (regulatory gene of bdcA). Mutants were validated by sequencing and Reverse transcription-PCR and monitored for biofilm formation by XTT method and confocal microscopy. The antibiotic susceptibility of the mutants was also ascertained. The results indicated that biofilm formation was inhibited in five mutants (ΔbdcR, ΔmhpA, ΔmhpB, ΔryfA, and ΔtolA) and the thickness of biofilm reduced from 17.2 μm in the wildtype to 1.5 to 4.8 μm in the mutants. Mutants ΔytfR and ΔmdtO retained the potential to form biofilm. Complementation of the mutants with the wild type gene restored biofilm formation potential in all mutants except in ΔmhpB. The 5 mutants which lost their ability to form biofilm (ΔbdcR, ΔmhpA, ΔmhpB, ΔtolA, and ΔryfA) did not exhibit any change in their susceptibility to Ceftazidime, Cefuroxime, Ciprofloxacin, Gentamicin, Cefotaxime, Sulfamethoxazole, Imipenem, Erythromycin, and Streptomycin in the planktonic phase compared to wild type ocular E. coli. But ΔmdtO was the only mutant with altered MIC to Sulfamethoxazole, Imipenem, Erythromycin, and Streptomycin both in the planktonic and biofilm phase. This is the first report demonstrating the involvement of the metabolic genes mhpA and mhpB and bdcR (regulatory gene of bdcA) in biofilm formation in ocular E. coli. In addition we provide evidence that tolA and ryfA are required for biofilm formation while ytfR and mdtO are not required. Mitigation of biofilm formation to overcome antibiotic resistance could be achieved by targeting the genes bdcR, mhpA, mhpB, ryfA, and tolA.
Collapse
Affiliation(s)
- Konduri Ranjith
- Jhaveri Microbiology Centre - Prof. Brien Holden Eye Research Centre, LV Prasad Eye Institute, Hyderabad, India.,Research Scholar, Manipal Academy of Higher Education, Manipal, India
| | - Jahnabi Ramchiary
- Department of Biotechnology and Bioinformatics, School of Life Sciences, University of Hyderabad, Hyderabad, India
| | - Jogadhenu S S Prakash
- Department of Biotechnology and Bioinformatics, School of Life Sciences, University of Hyderabad, Hyderabad, India
| | - Kotakonda Arunasri
- Jhaveri Microbiology Centre - Prof. Brien Holden Eye Research Centre, LV Prasad Eye Institute, Hyderabad, India
| | - Savitri Sharma
- Jhaveri Microbiology Centre - Prof. Brien Holden Eye Research Centre, LV Prasad Eye Institute, Hyderabad, India
| | - Sisinthy Shivaji
- Jhaveri Microbiology Centre - Prof. Brien Holden Eye Research Centre, LV Prasad Eye Institute, Hyderabad, India
| |
Collapse
|
11
|
McNally A, Kallonen T, Connor C, Abudahab K, Aanensen DM, Horner C, Peacock SJ, Parkhill J, Croucher NJ, Corander J. Diversification of Colonization Factors in a Multidrug-Resistant Escherichia coli Lineage Evolving under Negative Frequency-Dependent Selection. mBio 2019; 10:e00644-19. [PMID: 31015329 PMCID: PMC6479005 DOI: 10.1128/mbio.00644-19] [Citation(s) in RCA: 71] [Impact Index Per Article: 14.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/20/2019] [Accepted: 03/21/2019] [Indexed: 12/18/2022] Open
Abstract
Escherichia coli is a major cause of bloodstream and urinary tract infections globally. The wide dissemination of multidrug-resistant (MDR) strains of extraintestinal pathogenic E. coli (ExPEC) poses a rapidly increasing public health burden due to narrowed treatment options and increased risk of failure to clear an infection. Here, we present a detailed population genomic analysis of the ExPEC ST131 clone, in which we seek explanations for its success as an emerging pathogenic strain beyond the acquisition of antimicrobial resistance (AMR) genes. We show evidence for evolution toward separate ecological niches for the main clades of ST131 and differential evolution of anaerobic metabolism, key colonization, and virulence factors. We further demonstrate that negative frequency-dependent selection acting across accessory loci is a major mechanism that has shaped the population evolution of this pathogen.IMPORTANCE Infections with multidrug-resistant (MDR) strains of Escherichia coli are a significant global public health concern. To combat these pathogens, we need a deeper understanding of how they evolved from their background populations. By understanding the processes that underpin their emergence, we can design new strategies to limit evolution of new clones and combat existing clones. By combining population genomics with modelling approaches, we show that dominant MDR clones of E. coli are under the influence of negative frequency-dependent selection, preventing them from rising to fixation in a population. Furthermore, we show that this selection acts on genes involved in anaerobic metabolism, suggesting that this key trait, and the ability to colonize human intestinal tracts, is a key step in the evolution of MDR clones of E. coli.
Collapse
Affiliation(s)
- Alan McNally
- Institute of Microbiology and Infection, University of Birmingham, Birmingham, United Kingdom
| | - Teemu Kallonen
- Infection Genomics, Wellcome Sanger Institute, Cambridge, United Kingdom
- Department of Biostatistics, University of Oslo, Oslo, Norway
| | - Christopher Connor
- Institute of Microbiology and Infection, University of Birmingham, Birmingham, United Kingdom
| | - Khalil Abudahab
- Infection Genomics, Wellcome Sanger Institute, Cambridge, United Kingdom
| | - David M Aanensen
- Infection Genomics, Wellcome Sanger Institute, Cambridge, United Kingdom
| | - Carolyne Horner
- British Society of Antimicrobial Chemotherapy, Birmingham, United Kingdom
| | - Sharon J Peacock
- Infection Genomics, Wellcome Sanger Institute, Cambridge, United Kingdom
- Department of Medicine, University of Cambridge, Cambridge, United Kingdom
- London School of Hygiene and Tropical Medicine, London, United Kingdom
| | - Julian Parkhill
- Infection Genomics, Wellcome Sanger Institute, Cambridge, United Kingdom
| | - Nicholas J Croucher
- Faculty of Medicine, School of Public Health, Imperial College, London, United Kingdom
| | - Jukka Corander
- Infection Genomics, Wellcome Sanger Institute, Cambridge, United Kingdom
- Department of Biostatistics, University of Oslo, Oslo, Norway
- Department of Mathematics and Statistics, University of Helsinki, Helsinki, Finland
| |
Collapse
|
12
|
The Prophages of Citrobacter rodentium Represent a Conserved Family of Horizontally Acquired Mobile Genetic Elements Associated with Enteric Evolution towards Pathogenicity. J Bacteriol 2019; 201:JB.00638-18. [PMID: 30782635 PMCID: PMC6456863 DOI: 10.1128/jb.00638-18] [Citation(s) in RCA: 11] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/25/2018] [Accepted: 01/23/2019] [Indexed: 01/08/2023] Open
Abstract
Bacteriophages are obligate intracellular parasites of bacteria. Some bacteriophages can confer novel bacterial phenotypes, including pathogenicity, through horizontal gene transfer (HGT). The pathogenic bacterium Citrobacter rodentium infects mice using mechanisms similar to those employed by human gastrointestinal pathogens, making it an important model organism. Here, we examined the 10 prophages of C. rodentium, investigating their roles in its evolution toward virulence. We characterized ΦNP and ΦSM, two endogenous active temperate bacteriophages likely important for HGT. We showed that the 10 prophages encode predicted virulence factors and are conserved within other intestinal pathogens. Phylogenetic analysis suggested that they represent a conserved family of horizontally acquired enteric-bacterium-associated pathogenic determinants. Consequently, similar analysis of prophage elements in other pathogens might further understanding of their evolution and pathology. Prophage-mediated horizontal gene transfer (HGT) plays a key role in the evolution of bacteria, enabling access to new environmental niches, including pathogenicity. Citrobacter rodentium is a host-adapted intestinal mouse pathogen and important model organism for attaching and effacing (A/E) pathogens, including the clinically significant enterohaemorrhagic and enteropathogenic Escherichia coli (EHEC and EPEC, respectively). Even though C. rodentium contains 10 prophage genomic regions, including an active temperate phage, ΦNP, little was known regarding the nature of C. rodentium prophages in the bacterium’s evolution toward pathogenicity. In this study, our characterization of ΦNP led to the discovery of a second, fully functional temperate phage, named ΦSM. We identify the bacterial host receptor for both phages as lipopolysaccharide (LPS). ΦNP and ΦSM are likely important mediators of HGT in C. rodentium. Bioinformatic analysis of the 10 prophage regions reveals cargo genes encoding known virulence factors, including several type III secretion system (T3SS) effectors. C. rodentium prophages are conserved across a wide range of pathogenic enteric bacteria, including EPEC and EHEC as well as pathogenic strains of Salmonella enterica, Shigella boydii, and Klebsiella pneumoniae. Phylogenetic analysis of core enteric backbone genes compared against prophage evolutionary models suggests that these prophages represent an important, conserved family of horizontally acquired enteric-bacterium-associated pathogenicity determinants. In addition to highlighting the transformative role of bacteriophage-mediated HGT in C. rodentium’s evolution toward pathogenicity, these data suggest that the examination of conserved families of prophages in other pathogenic bacteria and disease outbreaks might provide deeper evolutionary and pathological insights otherwise obscured by more classical analysis. IMPORTANCE Bacteriophages are obligate intracellular parasites of bacteria. Some bacteriophages can confer novel bacterial phenotypes, including pathogenicity, through horizontal gene transfer (HGT). The pathogenic bacterium Citrobacter rodentium infects mice using mechanisms similar to those employed by human gastrointestinal pathogens, making it an important model organism. Here, we examined the 10 prophages of C. rodentium, investigating their roles in its evolution toward virulence. We characterized ΦNP and ΦSM, two endogenous active temperate bacteriophages likely important for HGT. We showed that the 10 prophages encode predicted virulence factors and are conserved within other intestinal pathogens. Phylogenetic analysis suggested that they represent a conserved family of horizontally acquired enteric-bacterium-associated pathogenic determinants. Consequently, similar analysis of prophage elements in other pathogens might further understanding of their evolution and pathology.
Collapse
|
13
|
Bhattacharya S, Baidya AK, Pal RR, Mamou G, Gatt YE, Margalit H, Rosenshine I, Ben-Yehuda S. A Ubiquitous Platform for Bacterial Nanotube Biogenesis. Cell Rep 2019; 27:334-342.e10. [PMID: 30929979 PMCID: PMC6456723 DOI: 10.1016/j.celrep.2019.02.055] [Citation(s) in RCA: 30] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/08/2018] [Revised: 02/05/2019] [Accepted: 02/13/2019] [Indexed: 01/01/2023] Open
Abstract
We have previously described the existence of membranous nanotubes, bridging adjacent bacteria, facilitating intercellular trafficking of nutrients, cytoplasmic proteins, and even plasmids, yet components enabling their biogenesis remain elusive. Here we reveal the identity of a molecular apparatus providing a platform for nanotube biogenesis. Using Bacillus subtilis (Bs), we demonstrate that conserved components of the flagellar export apparatus (FliO, FliP, FliQ, FliR, FlhB, and FlhA), designated CORE, dually serve for flagellum and nanotube assembly. Mutants lacking CORE genes, but not other flagellar components, are deficient in both nanotube production and the associated intercellular molecular trafficking. In accord, CORE components are located at sites of nanotube emergence. Deleting COREs of distinct species established that CORE-mediated nanotube formation is widespread. Furthermore, exogenous COREs from diverse species could restore nanotube generation and functionality in Bs lacking endogenous CORE. Our results demonstrate that the CORE-derived nanotube is a ubiquitous organelle that facilitates intercellular molecular trade across the bacterial kingdom. Conserved flagellar CORE components dually serve for flagella and nanotube assembly CORE mutants are deficient in nanotube formation and intercellular molecular trade CORE-dependent nanotube production is conserved among distinct bacterial species The CORE-nanotube organelle can provide a common path for bacterial molecular trade
Collapse
Affiliation(s)
- Saurabh Bhattacharya
- Department of Microbiology and Molecular Genetics, Institute for Medical Research Israel-Canada, The Hebrew University-Hadassah Medical School, POB 12272, The Hebrew University of Jerusalem, 91120 Jerusalem, Israel
| | - Amit K Baidya
- Department of Microbiology and Molecular Genetics, Institute for Medical Research Israel-Canada, The Hebrew University-Hadassah Medical School, POB 12272, The Hebrew University of Jerusalem, 91120 Jerusalem, Israel
| | - Ritesh Ranjan Pal
- Department of Microbiology and Molecular Genetics, Institute for Medical Research Israel-Canada, The Hebrew University-Hadassah Medical School, POB 12272, The Hebrew University of Jerusalem, 91120 Jerusalem, Israel
| | - Gideon Mamou
- Department of Microbiology and Molecular Genetics, Institute for Medical Research Israel-Canada, The Hebrew University-Hadassah Medical School, POB 12272, The Hebrew University of Jerusalem, 91120 Jerusalem, Israel
| | - Yair E Gatt
- Department of Microbiology and Molecular Genetics, Institute for Medical Research Israel-Canada, The Hebrew University-Hadassah Medical School, POB 12272, The Hebrew University of Jerusalem, 91120 Jerusalem, Israel
| | - Hanah Margalit
- Department of Microbiology and Molecular Genetics, Institute for Medical Research Israel-Canada, The Hebrew University-Hadassah Medical School, POB 12272, The Hebrew University of Jerusalem, 91120 Jerusalem, Israel
| | - Ilan Rosenshine
- Department of Microbiology and Molecular Genetics, Institute for Medical Research Israel-Canada, The Hebrew University-Hadassah Medical School, POB 12272, The Hebrew University of Jerusalem, 91120 Jerusalem, Israel.
| | - Sigal Ben-Yehuda
- Department of Microbiology and Molecular Genetics, Institute for Medical Research Israel-Canada, The Hebrew University-Hadassah Medical School, POB 12272, The Hebrew University of Jerusalem, 91120 Jerusalem, Israel.
| |
Collapse
|
14
|
Garrido-Sanz D, Redondo-Nieto M, Mongiardini E, Blanco-Romero E, Durán D, Quelas JI, Martin M, Rivilla R, Lodeiro AR, Althabegoiti MJ. Phylogenomic Analyses of Bradyrhizobium Reveal Uneven Distribution of the Lateral and Subpolar Flagellar Systems, Which Extends to Rhizobiales. Microorganisms 2019; 7:microorganisms7020050. [PMID: 30781830 PMCID: PMC6406911 DOI: 10.3390/microorganisms7020050] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/19/2018] [Revised: 02/10/2019] [Accepted: 02/11/2019] [Indexed: 11/20/2022] Open
Abstract
Dual flagellar systems have been described in several bacterial genera, but the extent of their prevalence has not been fully explored. Bradyrhizobium diazoefficiens USDA 110T possesses two flagellar systems, the subpolar and the lateral flagella. The lateral flagellum of Bradyrhizobium displays no obvious role, since its performance is explained by cooperation with the subpolar flagellum. In contrast, the lateral flagellum is the only type of flagella present in the related Rhizobiaceae family. In this work, we have analyzed the phylogeny of the Bradyrhizobium genus by means of Genome-to-Genome Blast Distance Phylogeny (GBDP) and Average Nucleotide Identity (ANI) comparisons of 128 genomes and divided it into 13 phylogenomic groups. While all the Bradyrhizobium genomes encode the subpolar flagellum, none of them encodes only the lateral flagellum. The simultaneous presence of both flagella is exclusive of the B. japonicum phylogenomic group. Additionally, 292 Rhizobiales order genomes were analyzed and both flagellar systems are present together in only nine genera. Phylogenetic analysis of 150 representative Rhizobiales genomes revealed an uneven distribution of these flagellar systems. While genomes within and close to the Rhizobiaceae family only possess the lateral flagellum, the subpolar flagellum is exclusive of more early-diverging families, where certain genera also present both flagella.
Collapse
Affiliation(s)
- Daniel Garrido-Sanz
- Departamento de Biología, Facultad de Ciencias, Universidad Autónoma de Madrid, c/Darwin 2, 28049 Madrid, Spain.
| | - Miguel Redondo-Nieto
- Departamento de Biología, Facultad de Ciencias, Universidad Autónoma de Madrid, c/Darwin 2, 28049 Madrid, Spain.
| | - Elías Mongiardini
- Instituto de Biotecnología y Biología Molecular (IBBM), Facultad de Ciencias Exactas, UNLP y CCT-La Plata-CONICET, La Plata B1900, Argentina.
| | - Esther Blanco-Romero
- Departamento de Biología, Facultad de Ciencias, Universidad Autónoma de Madrid, c/Darwin 2, 28049 Madrid, Spain.
| | - David Durán
- Departamento de Biología, Facultad de Ciencias, Universidad Autónoma de Madrid, c/Darwin 2, 28049 Madrid, Spain.
| | - Juan I Quelas
- Instituto de Biotecnología y Biología Molecular (IBBM), Facultad de Ciencias Exactas, UNLP y CCT-La Plata-CONICET, La Plata B1900, Argentina.
| | - Marta Martin
- Departamento de Biología, Facultad de Ciencias, Universidad Autónoma de Madrid, c/Darwin 2, 28049 Madrid, Spain.
| | - Rafael Rivilla
- Departamento de Biología, Facultad de Ciencias, Universidad Autónoma de Madrid, c/Darwin 2, 28049 Madrid, Spain.
| | - Aníbal R Lodeiro
- Instituto de Biotecnología y Biología Molecular (IBBM), Facultad de Ciencias Exactas, UNLP y CCT-La Plata-CONICET, La Plata B1900, Argentina.
| | - M Julia Althabegoiti
- Instituto de Biotecnología y Biología Molecular (IBBM), Facultad de Ciencias Exactas, UNLP y CCT-La Plata-CONICET, La Plata B1900, Argentina.
| |
Collapse
|
15
|
Roux D, Schaefers M, Clark BS, Weatherholt M, Renaud D, Scott D, LiPuma JJ, Priebe G, Gerard C, Yoder-Himes DR. A putative lateral flagella of the cystic fibrosis pathogen Burkholderia dolosa regulates swimming motility and host cytokine production. PLoS One 2018; 13:e0189810. [PMID: 29346379 PMCID: PMC5773237 DOI: 10.1371/journal.pone.0189810] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/25/2017] [Accepted: 12/01/2017] [Indexed: 01/25/2023] Open
Abstract
Burkholderia dolosa caused an outbreak in the cystic fibrosis clinic at Boston Children's Hospital and was associated with high mortality in these patients. This species is part of a larger complex of opportunistic pathogens known as the Burkholderia cepacia complex (Bcc). Compared to other species in the Bcc, B. dolosa is highly transmissible; thus understanding its virulence mechanisms is important for preventing future outbreaks. The genome of one of the outbreak strains, AU0158, revealed a homolog of the lafA gene encoding a putative lateral flagellin, which, in other non-Bcc species, is used for movement on solid surfaces, attachment to host cells, or movement inside host cells. Here, we analyzed the conservation of the lafA gene and protein sequences, which are distinct from those of the polar flagella, and found lafA homologs to be present in numerous β-proteobacteria but notably absent from most other Bcc species. A lafA deletion mutant in B. dolosa showed a greater swimming motility than wild-type due to an increase in the number of polar flagella, but did not appear to contribute to biofilm formation, host cell invasion, or murine lung colonization or persistence over time. However, the lafA gene was important for cytokine production in human peripheral blood mononuclear cells, suggesting it may have a role in recognition by the human immune response.
Collapse
Affiliation(s)
- Damien Roux
- INSERM, IAME, UMR 1137, Paris, France
- Univ Paris Diderot, Sorbonne Paris Cité, Paris, France
- AP-HP, Louis Mourier Hospital, Intensive Care Unit, Colombes, France
| | - Matthew Schaefers
- Division of Critical Care Medicine, Department of Anesthesiology, Perioperative and Pain Medicine, Boston Children’s Hospital, Boston, Massachusetts, United States of America
- Department of Anesthesia, Harvard Medical School, Boston, Massachusetts, United States of America
| | - Bradley S. Clark
- Department of Biology, University of Louisville, Louisville, Kentucky, United States of America
| | - Molly Weatherholt
- Department of Biology, University of Louisville, Louisville, Kentucky, United States of America
| | - Diane Renaud
- Oral Immunology and Infectious Diseases, School of Dentistry, University of Louisville, Louisville, Kentucky, United States of America
| | - David Scott
- Oral Immunology and Infectious Diseases, School of Dentistry, University of Louisville, Louisville, Kentucky, United States of America
| | - John J. LiPuma
- Division of Pediatrics, University of Michigan, Ann Arbor, Michigan, United States of America
| | - Gregory Priebe
- Division of Critical Care Medicine, Department of Anesthesiology, Perioperative and Pain Medicine, Boston Children’s Hospital, Boston, Massachusetts, United States of America
- Department of Anesthesia, Harvard Medical School, Boston, Massachusetts, United States of America
| | - Craig Gerard
- Division of Respiratory Diseases, Boston Children’s Hospital, Boston, Massachusetts, United States of America
| | - Deborah R. Yoder-Himes
- Department of Biology, University of Louisville, Louisville, Kentucky, United States of America
- * E-mail:
| |
Collapse
|
16
|
Leimbach A, Poehlein A, Vollmers J, Görlich D, Daniel R, Dobrindt U. No evidence for a bovine mastitis Escherichia coli pathotype. BMC Genomics 2017; 18:359. [PMID: 28482799 PMCID: PMC5422975 DOI: 10.1186/s12864-017-3739-x] [Citation(s) in RCA: 38] [Impact Index Per Article: 5.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/27/2016] [Accepted: 04/27/2017] [Indexed: 11/30/2022] Open
Abstract
Background Escherichia coli bovine mastitis is a disease of significant economic importance in the dairy industry. Molecular characterization of mastitis-associated E. coli (MAEC) did not result in the identification of common traits. Nevertheless, a mammary pathogenic E. coli (MPEC) pathotype has been proposed suggesting virulence traits that differentiate MAEC from commensal E. coli. The present study was designed to investigate the MPEC pathotype hypothesis by comparing the genomes of MAEC and commensal bovine E. coli. Results We sequenced the genomes of eight E. coli isolated from bovine mastitis cases and six fecal commensal isolates from udder-healthy cows. We analyzed the phylogenetic history of bovine E. coli genomes by supplementing this strain panel with eleven bovine-associated E. coli from public databases. The majority of the isolates originate from phylogroups A and B1, but neither MAEC nor commensal strains could be unambiguously distinguished by phylogenetic lineage. The gene content of both MAEC and commensal strains is highly diverse and dominated by their phylogenetic background. Although individual strains carry some typical E. coli virulence-associated genes, no traits important for pathogenicity could be specifically attributed to MAEC. Instead, both commensal strains and MAEC have very few gene families enriched in either pathotype. Only the aerobactin siderophore gene cluster was enriched in commensal E. coli within our strain panel. Conclusions This is the first characterization of a phylogenetically diverse strain panel including several MAEC and commensal isolates. With our comparative genomics approach we could not confirm previous studies that argue for a positive selection of specific traits enabling MAEC to elicit bovine mastitis. Instead, MAEC are facultative and opportunistic pathogens recruited from the highly diverse bovine gastrointestinal microbiota. Virulence-associated genes implicated in mastitis are a by-product of commensalism with the primary function to enhance fitness in the bovine gastrointestinal tract. Therefore, we put the definition of the MPEC pathotype into question and suggest to designate corresponding isolates as MAEC. Electronic supplementary material The online version of this article (doi:10.1186/s12864-017-3739-x) contains supplementary material, which is available to authorized users.
Collapse
Affiliation(s)
- Andreas Leimbach
- Institute of Hygiene, University of Münster, Mendelstrasse 7, 48149, Münster, Germany. .,Department of Genomic and Applied Microbiology, Göttingen Genomics Laboratory, Institute of Microbiology and Genetics, Georg-August-University of Göttingen, Göttingen, Germany. .,Institute for Molecular Infection Biology, Julius-Maximilians-University of Würzburg, Würzburg, Germany.
| | - Anja Poehlein
- Department of Genomic and Applied Microbiology, Göttingen Genomics Laboratory, Institute of Microbiology and Genetics, Georg-August-University of Göttingen, Göttingen, Germany
| | - John Vollmers
- Leibniz Institute DSMZ, German Collection of Microorganisms and Cell Cultures, Braunschweig, Germany
| | - Dennis Görlich
- Institute of Biostatistics and Clinical Research, University of Münster, Münster, Germany
| | - Rolf Daniel
- Department of Genomic and Applied Microbiology, Göttingen Genomics Laboratory, Institute of Microbiology and Genetics, Georg-August-University of Göttingen, Göttingen, Germany
| | - Ulrich Dobrindt
- Institute of Hygiene, University of Münster, Mendelstrasse 7, 48149, Münster, Germany. .,Institute for Molecular Infection Biology, Julius-Maximilians-University of Würzburg, Würzburg, Germany.
| |
Collapse
|
17
|
Horstmann JA, Zschieschang E, Truschel T, de Diego J, Lunelli M, Rohde M, May T, Strowig T, Stradal T, Kolbe M, Erhardt M. Flagellin phase-dependent swimming on epithelial cell surfaces contributes to productive Salmonella gut colonisation. Cell Microbiol 2017; 19. [PMID: 28295924 DOI: 10.1111/cmi.12739] [Citation(s) in RCA: 37] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/03/2017] [Accepted: 03/08/2017] [Indexed: 12/11/2022]
Abstract
The flagellum is a sophisticated nanomachine and an important virulence factor of many pathogenic bacteria. Flagellar motility enables directed movements towards host cells in a chemotactic process, and near-surface swimming on cell surfaces is crucial for selection of permissive entry sites. The long external flagellar filament is made of tens of thousands subunits of a single protein, flagellin, and many Salmonella serovars alternate expression of antigenically distinct flagellin proteins, FliC and FljB. However, the role of the different flagellin variants during gut colonisation and host cell invasion remains elusive. Here, we demonstrate that flagella made of different flagellin variants display structural differences and affect Salmonella's swimming behaviour on host cell surfaces. We observed a distinct advantage of bacteria expressing FliC-flagella to identify target sites on host cell surfaces and to invade epithelial cells. FliC-expressing bacteria outcompeted FljB-expressing bacteria for intestinal tissue colonisation in the gastroenteritis and typhoid murine infection models. Intracellular survival and responses of the host immune system were not altered. We conclude that structural properties of flagella modulate the swimming behaviour on host cell surfaces, which facilitates the search for invasion sites and might constitute a general mechanism for productive host cell invasion of flagellated bacteria.
Collapse
Affiliation(s)
- Julia A Horstmann
- Junior Research Group Infection Biology of Salmonella, Helmholtz Centre for Infection Research, Braunschweig, Germany
| | - Erik Zschieschang
- Department for Structural Infection Biology, Center for Structural Systems Biology, Hamburg, Germany.,Department for Structural Infection Biology, Helmholtz Centre for Infection Research, Braunschweig, Germany
| | | | - Juana de Diego
- Department for Structural Infection Biology, Center for Structural Systems Biology, Hamburg, Germany.,Department for Structural Infection Biology, Helmholtz Centre for Infection Research, Braunschweig, Germany
| | - Michele Lunelli
- Department for Structural Infection Biology, Center for Structural Systems Biology, Hamburg, Germany.,Department for Structural Infection Biology, Helmholtz Centre for Infection Research, Braunschweig, Germany
| | - Manfred Rohde
- Central Facility for Microscopy, Helmholtz Centre for Infection Research, Braunschweig, Germany
| | | | - Till Strowig
- Junior Research Group Microbial Immune Regulation, Helmholtz Centre for Infection Research, Braunschweig, Germany
| | - Theresia Stradal
- Department of Cell Biology, Helmholtz Centre for Infection Research, Braunschweig, Germany
| | - Michael Kolbe
- Department for Structural Infection Biology, Center for Structural Systems Biology, Hamburg, Germany.,Department for Structural Infection Biology, Helmholtz Centre for Infection Research, Braunschweig, Germany.,MIN-Faculty University Hamburg, Hamburg, Germany
| | - Marc Erhardt
- Junior Research Group Infection Biology of Salmonella, Helmholtz Centre for Infection Research, Braunschweig, Germany
| |
Collapse
|
18
|
Ranjith K, Arunasri K, Reddy GS, Adicherla H, Sharma S, Shivaji S. Global gene expression in Escherichia coli, isolated from the diseased ocular surface of the human eye with a potential to form biofilm. Gut Pathog 2017; 9:15. [PMID: 28392838 PMCID: PMC5379667 DOI: 10.1186/s13099-017-0164-2] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 02/16/2017] [Accepted: 03/25/2017] [Indexed: 01/10/2023] Open
Abstract
Background Escherichia coli, the gastrointestinal commensal, is also known to cause ocular infections such as conjunctivitis, keratitis and endophthalmitis. These infections are normally resolved by topical application of an appropriate antibiotic. But, at times these E. coli are resistant to the antibiotic and this could be due to formation of a biofilm. In this study ocular E. coli from patients with conjunctivitis, keratitis or endophthalmitis were screened for their antibiotic susceptibility and biofilm formation potential. In addition DNA-microarray analysis was done to identify genes that are involved in biofilm formation and antibiotic resistance. Results Out of 12 ocular E. coli isolated from patients ten isolates were resistant to one or more of the nine antibiotics tested and majority of the isolates were positive for biofilm formation. In E. coli L-1216/2010, the best biofilm forming isolate, biofilm formation was confirmed by scanning electron microscopy. Confocal laser scanning microscopic studies indicated that the thickness of the biofilm increased up to 72 h of growth. Further, in the biofilm phase, E. coli L-1216/2010 was 100 times more resistant to the eight antibiotics tested compared to planktonic phase. DNA microarray analysis indicated that in biofilm forming E. coli L-1216/2010 genes encoding biofilm formation such as cell adhesion genes, LPS production genes, genes required for biofilm architecture and extracellular matrix remodeling and genes encoding for proteins that are integral to the cell membrane and those that influence antigen presentation are up regulated during biofilm formation. In addition genes that confer antimicrobial resistance such as genes encoding antimicrobial efflux (mdtM and cycA), virulence (insQ, yjgK), toxin production (sat, yjgK, chpS, chpB and ygjN), transport of amino-acids and other metabolites (cbrB, cbrC, hisI and mglB) are also up regulated. These genes could serve as potential targets for developing strategies for hacking biofilms and overcoming antibiotic resistance. Conclusions This is the first study on global gene expression in antibiotic resistant ocular E. coli with a potential to form biofilm. Using native ocular isolates for antibiotic susceptibility testing, for biofilm formation and global gene expression is relevant and more acceptable than using type strains or non clinical strains which do not necessarily mimic the native isolate. Electronic supplementary material The online version of this article (doi:10.1186/s13099-017-0164-2) contains supplementary material, which is available to authorized users.
Collapse
Affiliation(s)
- Konduri Ranjith
- Jhaveri Microbiology Centre, Brien Holden Eye Research Centre, L V Prasad Eye Institute, Kallam Anji Reddy campus, Hyderabad, 500007 India.,Research Scholar, Manipal University, Manipal, Karnataka 576104 India
| | - Kotakonda Arunasri
- Jhaveri Microbiology Centre, Brien Holden Eye Research Centre, L V Prasad Eye Institute, Kallam Anji Reddy campus, Hyderabad, 500007 India
| | | | | | - Savitri Sharma
- Jhaveri Microbiology Centre, Brien Holden Eye Research Centre, L V Prasad Eye Institute, Kallam Anji Reddy campus, Hyderabad, 500007 India
| | - Sisinthy Shivaji
- Jhaveri Microbiology Centre, Brien Holden Eye Research Centre, L V Prasad Eye Institute, Kallam Anji Reddy campus, Hyderabad, 500007 India
| |
Collapse
|
19
|
Liu F, Fu J, Liu C, Chen J, Sun M, Chen H, Tan C, Wang X. Characterization and distinction of two flagellar systems in extraintestinal pathogenic Escherichia coli PCN033. Microbiol Res 2016; 196:69-79. [PMID: 28164791 DOI: 10.1016/j.micres.2016.11.013] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/22/2016] [Revised: 10/30/2016] [Accepted: 11/26/2016] [Indexed: 01/09/2023]
Abstract
Extraintestinal pathogenic Escherichia coli (ExPEC) can invade and colonize multiple extraintestinal tissues and can cause a wide range of infections; however the mechanisms of its pathogenicity are not well understood. Flagella contribute to the infection of E. coli strains by mediating adhesion and invasion. Our previous bioinformatic analysis revealed two flagella gene clusters in the genome of an ExPEC isolate, PCN033. One encodes the conventional flagellum system (Flag-1) and the other encodes the Flag-2 system, whose function is uncharacterized. Here we aimed to characterize these two flagellum systems and determine their contributions to the flagellum formation and certain pathogenicity-associated phenotypes. Our observations support the involvement of Flag-1 system, but not Flag-2 system, in the synthesis and maturation of the flagellum structure, and in mediating bacterial swimming and swarming. Moreover, flgD, which encodes a flagellar-hook scaffolding protein in the Flag-1 system, is required for flagellum assembly by influencing the production of FliC (flagellin). Deletion of flgD attenuated ExPEC strain PCN033 invasion and colonization in vivo, probably by affecting bacterial adhesion and invasion, and by reducing resistance to phagocytosis by circulating monocytes. In contrast, these phenotypes were not observed in the strain with deletion of lfgD, encoding the FlgD-like protein in the Flag-2 system. Taken together, these findings indicate that Flag-1 flagellum system is the determinative component of bacterial flagella that contributes to the infection.
Collapse
Affiliation(s)
- Feng Liu
- State Key Laboratory of Agricultural Microbiology, College of Veterinary Medicine, Huazhong Agricultural University, Wuhan, Hubei, China; The Cooperative Innovation Center for Sustainable Pig Production, Huazhong Agricultural University, Wuhan, Hubei, China
| | - Jiyang Fu
- State Key Laboratory of Agricultural Microbiology, College of Veterinary Medicine, Huazhong Agricultural University, Wuhan, Hubei, China; The Cooperative Innovation Center for Sustainable Pig Production, Huazhong Agricultural University, Wuhan, Hubei, China
| | - Canying Liu
- Department of Veterinary Medicine, Foshan University, Foshan, Guangdong, China
| | - Jing Chen
- State Key Laboratory of Agricultural Microbiology, College of Veterinary Medicine, Huazhong Agricultural University, Wuhan, Hubei, China; The Cooperative Innovation Center for Sustainable Pig Production, Huazhong Agricultural University, Wuhan, Hubei, China
| | - Minhua Sun
- Guangdong Lab for Animal Diseases/Guangdong Open Laboratory of Public Health, Institute of Animal Health, Guangdong Academy of Agricultural Sciences, Guangzhou, China
| | - Huanchun Chen
- State Key Laboratory of Agricultural Microbiology, College of Veterinary Medicine, Huazhong Agricultural University, Wuhan, Hubei, China; The Cooperative Innovation Center for Sustainable Pig Production, Huazhong Agricultural University, Wuhan, Hubei, China; Key Laboratory of development of veterinary diagnostic products of Ministry of Agriculture, Huazhong Agricultural University, Wuhan, Hubei, China
| | - Chen Tan
- State Key Laboratory of Agricultural Microbiology, College of Veterinary Medicine, Huazhong Agricultural University, Wuhan, Hubei, China; The Cooperative Innovation Center for Sustainable Pig Production, Huazhong Agricultural University, Wuhan, Hubei, China; Key Laboratory of development of veterinary diagnostic products of Ministry of Agriculture, Huazhong Agricultural University, Wuhan, Hubei, China.
| | - Xiangru Wang
- State Key Laboratory of Agricultural Microbiology, College of Veterinary Medicine, Huazhong Agricultural University, Wuhan, Hubei, China; The Cooperative Innovation Center for Sustainable Pig Production, Huazhong Agricultural University, Wuhan, Hubei, China; Key Laboratory of development of veterinary diagnostic products of Ministry of Agriculture, Huazhong Agricultural University, Wuhan, Hubei, China.
| |
Collapse
|
20
|
The Histone-Like Nucleoid Structuring Protein (H-NS) Is a Negative Regulator of the Lateral Flagellar System in the Deep-Sea Bacterium Shewanella piezotolerans WP3. Appl Environ Microbiol 2016; 82:2388-2398. [PMID: 26873312 DOI: 10.1128/aem.00297-16] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/27/2016] [Accepted: 02/05/2016] [Indexed: 11/20/2022] Open
Abstract
Although the histone-like nucleoid structuring protein (H-NS) is well known for its involvement in the adaptation of mesophilic bacteria, such as Escherichia coli, to cold environments and high-pressure stress, an understanding of the role of H-NS in the cold-adapted benthic microorganisms that live in the deep-sea ecosystem, which covers approximately 60% of the earth's surface, is still lacking. In this study, we characterized the function of H-NS in Shewanella piezotolerans WP3, which was isolated from West Pacific sediment at a depth of 1,914 m. Anhns gene deletion mutant (WP3Δhns) was constructed, and comparative whole-genome microarray analysis was performed. H-NS had a significant influence (fold change, >2) on the expression of a variety of WP3 genes (274 and 280 genes were upregulated and downregulated, respectively), particularly genes related to energy production and conversion. Notably, WP3Δhnsexhibited higher expression levels of lateral flagellar genes than WP3 and showed enhanced swarming motility and lateral flagellar production compared to those of WP3. The DNA gel mobility shift experiment showed that H-NS bound specifically to the promoter of lateral flagellar genes. Moreover, the high-affinity binding sequences of H-NS were identified by DNase I protection footprinting, and the results support the "binding and spreading" model for H-NS functioning. To our knowledge, this is the first attempt to characterize the function of the universal regulator H-NS in a deep-sea bacterium. Our data revealed that H-NS has a novel function as a repressor of the expression of genes related to the energy-consuming secondary flagellar system and to swarming motility.
Collapse
|
21
|
Abstract
Twenty years ago, the publication of the first bacterial genome sequence, from Haemophilus influenzae, shook the world of bacteriology. In this Timeline, we review the first two decades of bacterial genome sequencing, which have been marked by three revolutions: whole-genome shotgun sequencing, high-throughput sequencing and single-molecule long-read sequencing. We summarize the social history of sequencing and its impact on our understanding of the biology, diversity and evolution of bacteria, while also highlighting spin-offs and translational impact in the clinic. We look forward to a 'sequencing singularity', where sequencing becomes the method of choice for as-yet unthinkable applications in bacteriology and beyond.
Collapse
Affiliation(s)
- Nicholas J Loman
- Institute of Microbiology and Infection, University of Birmingham, Birmingham B15 2TT, UK
| | - Mark J Pallen
- Microbiology and Infection Unit, Warwick Medical School, University of Warwick, Coventry, CV4 7AL, UK
| |
Collapse
|
22
|
Kakkanat A, Totsika M, Schaale K, Duell BL, Lo AW, Phan MD, Moriel DG, Beatson SA, Sweet MJ, Ulett GC, Schembri MA. The role of H4 flagella in Escherichia coli ST131 virulence. Sci Rep 2015; 5:16149. [PMID: 26548325 PMCID: PMC4637896 DOI: 10.1038/srep16149] [Citation(s) in RCA: 28] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/01/2015] [Accepted: 10/02/2015] [Indexed: 01/04/2023] Open
Abstract
Escherichia coli sequence type 131 (ST131) is a globally dominant multidrug resistant clone associated with urinary tract and bloodstream infections. Most ST131 strains exhibit resistance to multiple antibiotics and cause infections associated with limited treatment options. The largest sub-clonal ST131 lineage is resistant to fluoroquinolones, contains the type 1 fimbriae fimH30 allele and expresses an H4 flagella antigen. Flagella are motility organelles that contribute to UPEC colonisation of the upper urinary tract. In this study, we examined the specific role of H4 flagella in ST131 motility and interaction with host epithelial and immune cells. We show that the majority of H4-positive ST131 strains are motile and are enriched for flagella expression during static pellicle growth. We also tested the role of H4 flagella in ST131 through the construction of specific mutants, over-expression strains and isogenic mutants that expressed alternative H1 and H7 flagellar subtypes. Overall, our results revealed that H4, H1 and H7 flagella possess conserved phenotypes with regards to motility, epithelial cell adhesion, invasion and uptake by macrophages. In contrast, H4 flagella trigger enhanced induction of the anti-inflammatory cytokine IL-10 compared to H1 and H7 flagella, a property that may contribute to ST131 fitness in the urinary tract.
Collapse
Affiliation(s)
- Asha Kakkanat
- School of Chemistry and Molecular Biosciences, University of Queensland, Brisbane, Queensland, Australia.,Australian Infectious Diseases Research Centre, University of Queensland, Brisbane, Queensland, Australia
| | - Makrina Totsika
- Institute of Health and Biomedical Innovation, School of Biomedical Sciences, Queensland University of Technology, Brisbane, Queensland, Australia
| | - Kolja Schaale
- Institute for Molecular Bioscience, University of Queensland, Brisbane, Queensland, Australia
| | - Benjamin L Duell
- School of Medical Science, and Menzies Health Institute Queensland, Griffith University, Gold Coast, Australia
| | - Alvin W Lo
- School of Chemistry and Molecular Biosciences, University of Queensland, Brisbane, Queensland, Australia.,Australian Infectious Diseases Research Centre, University of Queensland, Brisbane, Queensland, Australia
| | - Minh-Duy Phan
- School of Chemistry and Molecular Biosciences, University of Queensland, Brisbane, Queensland, Australia.,Australian Infectious Diseases Research Centre, University of Queensland, Brisbane, Queensland, Australia
| | - Danilo G Moriel
- School of Chemistry and Molecular Biosciences, University of Queensland, Brisbane, Queensland, Australia.,Australian Infectious Diseases Research Centre, University of Queensland, Brisbane, Queensland, Australia
| | - Scott A Beatson
- School of Chemistry and Molecular Biosciences, University of Queensland, Brisbane, Queensland, Australia.,Australian Infectious Diseases Research Centre, University of Queensland, Brisbane, Queensland, Australia
| | - Matthew J Sweet
- Australian Infectious Diseases Research Centre, University of Queensland, Brisbane, Queensland, Australia.,Institute for Molecular Bioscience, University of Queensland, Brisbane, Queensland, Australia
| | - Glen C Ulett
- School of Medical Science, and Menzies Health Institute Queensland, Griffith University, Gold Coast, Australia
| | - Mark A Schembri
- School of Chemistry and Molecular Biosciences, University of Queensland, Brisbane, Queensland, Australia.,Australian Infectious Diseases Research Centre, University of Queensland, Brisbane, Queensland, Australia
| |
Collapse
|
23
|
Liu C, Zheng H, Yang M, Xu Z, Wang X, Wei L, Tang B, Liu F, Zhang Y, Ding Y, Tang X, Wu B, Johnson TJ, Chen H, Tan C. Genome analysis and in vivo virulence of porcine extraintestinal pathogenic Escherichia coli strain PCN033. BMC Genomics 2015; 16:717. [PMID: 26391348 PMCID: PMC4578781 DOI: 10.1186/s12864-015-1890-9] [Citation(s) in RCA: 53] [Impact Index Per Article: 5.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/07/2015] [Accepted: 09/01/2015] [Indexed: 11/17/2022] Open
Abstract
Background Strains of extraintestinal pathogenic Escherichia coli (ExPEC) can invade and colonize extraintestinal sites and cause a wide range of infections. Genomic analysis of ExPEC has mainly focused on isolates of human and avian origins, with porcine ExPEC isolates yet to be sequenced. To better understand the genomic attributes underlying the pathogenicity of porcine ExPEC, we isolated two E. coli strains PCN033 and PCN061 from pigs, assessed their in vivo virulence, and completed and compared their genomes. Results Animal experiments demonstrated that strain PCN033, but not PCN061, was pathogenic in a pig model. The chromosome of PCN033 was 384 kb larger than that of PCN061. Among the PCN033-specific sequences, genes encoding adhesins, unique lipopolysaccharide, unique capsular polysaccharide, iron acquisition and transport systems, and metabolism were identified. Additionally, a large plasmid PCN033p3 harboring many typical ExPEC virulence factors was identified in PCN033. Based on the genetic variation between PCN033 and PCN061, corresponding phenotypic differences in flagellum-dependent swarming motility and metabolism were verified. Furthermore, the comparative genomic analyses showed that the PCN033 genome shared many similarities with genomic sequences of human ExPEC strains. Additionally, comparison of PCN033 genome with other nine characteristic E. coli genomes revealed 425 PCN033-special coding sequences. Genes of this subset included those encoding type I restriction-modification (R-M) system, type VI secretion system (T6SS) and membrane-associated proteins. Conclusions The genetic and phenotypic differences between PCN033 and PCN061 could partially explain their differences in virulence, and also provide insight towards the molecular mechanisms of porcine ExPEC infections. Additionally, the similarities between the genomes of PCN033 and human ExPEC strains suggest that some connections between porcine and human ExPEC strains exist. The first completed genomic sequence for porcine ExPEC and the genomic differences identified by comparative analyses provide a baseline understanding of porcine ExPEC genetics and lay the foundation for their further study. Electronic supplementary material The online version of this article (doi:10.1186/s12864-015-1890-9) contains supplementary material, which is available to authorized users.
Collapse
Affiliation(s)
- Canying Liu
- State Key Laboratory of Agricultural Microbiology, College of Veterinary Medicine, Huazhong Agricultural University, Wuhan, China. .,Department of Veterinary Medicine, Foshan University, Foshan, Guangdong, China.
| | - Huajun Zheng
- Shanghai-Most Key Laboratory of Health and Disease Genomics, Chinese National Human Genome Center at Shanghai, Shanghai, China.
| | - Minjun Yang
- Shanghai-Most Key Laboratory of Health and Disease Genomics, Chinese National Human Genome Center at Shanghai, Shanghai, China.
| | - Zhuofei Xu
- State Key Laboratory of Agricultural Microbiology, College of Veterinary Medicine, Huazhong Agricultural University, Wuhan, China.
| | - Xiangru Wang
- State Key Laboratory of Agricultural Microbiology, College of Veterinary Medicine, Huazhong Agricultural University, Wuhan, China.
| | - Liuya Wei
- State Key Laboratory of Agricultural Microbiology, College of Veterinary Medicine, Huazhong Agricultural University, Wuhan, China.
| | - Biao Tang
- Shanghai-Most Key Laboratory of Health and Disease Genomics, Chinese National Human Genome Center at Shanghai, Shanghai, China. .,State Key Laboratory of Genetic Engineering, Department of Microbiology, School of Life Sciences, Fudan University, Shanghai, China.
| | - Feng Liu
- State Key Laboratory of Agricultural Microbiology, College of Veterinary Medicine, Huazhong Agricultural University, Wuhan, China.
| | - Yanyan Zhang
- State Key Laboratory of Agricultural Microbiology, College of Veterinary Medicine, Huazhong Agricultural University, Wuhan, China.
| | - Yi Ding
- State Key Laboratory of Agricultural Microbiology, College of Veterinary Medicine, Huazhong Agricultural University, Wuhan, China.
| | - Xibiao Tang
- State Key Laboratory of Agricultural Microbiology, College of Veterinary Medicine, Huazhong Agricultural University, Wuhan, China.
| | - Bin Wu
- State Key Laboratory of Agricultural Microbiology, College of Veterinary Medicine, Huazhong Agricultural University, Wuhan, China.
| | - Timothy J Johnson
- Department of Veterinary and Biomedical Sciences, University of Minnesota, Saint Paul, Minnesota, USA.
| | - Huanchun Chen
- State Key Laboratory of Agricultural Microbiology, College of Veterinary Medicine, Huazhong Agricultural University, Wuhan, China.
| | - Chen Tan
- State Key Laboratory of Agricultural Microbiology, College of Veterinary Medicine, Huazhong Agricultural University, Wuhan, China.
| |
Collapse
|
24
|
Merino S, Aquilini E, Fulton KM, Twine SM, Tomás JM. The polar and lateral flagella from Plesiomonas shigelloides are glycosylated with legionaminic acid. Front Microbiol 2015; 6:649. [PMID: 26167161 PMCID: PMC4481668 DOI: 10.3389/fmicb.2015.00649] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/30/2015] [Accepted: 06/15/2015] [Indexed: 12/30/2022] Open
Abstract
Plesiomonas shigelloides is the unique member of the Enterobacteriaceae family able to produce polar flagella when grow in liquid medium and lateral flagella when grown in solid or semisolid media. In this study on P. shigelloides 302-73 strain, we found two different gene clusters, one exclusively for the lateral flagella biosynthesis and the other one containing the biosynthetic polar flagella genes with additional putative glycosylation genes. P. shigelloides is the first Enterobacteriaceae were a complete lateral flagella cluster leading to a lateral flagella production is described. We also show that both flagella in P. shigelloides 302-73 strain are glycosylated by a derivative of legionaminic acid (Leg), which explains the presence of Leg pathway genes between the two polar flagella regions in their biosynthetic gene cluster. It is the first bacterium reported with O-glycosylated Leg in both polar and lateral flagella. The flagella O-glycosylation is essential for bacterial flagella formation, either polar or lateral, because gene mutants on the biosynthesis of Leg are non-flagellated. Furthermore, the presence of the lateral flagella cluster and Leg O-flagella glycosylation genes are widely spread features among the P. shigelloides strains tested.
Collapse
Affiliation(s)
- Susana Merino
- Departamento de Microbiología, Facultad de Biología, Universidad de Barcelona Barcelona, Spain
| | - Eleonora Aquilini
- Departamento de Microbiología, Facultad de Biología, Universidad de Barcelona Barcelona, Spain
| | | | | | - Juan M Tomás
- Departamento de Microbiología, Facultad de Biología, Universidad de Barcelona Barcelona, Spain
| |
Collapse
|
25
|
Maruyama Y, Kobayashi M, Murata K, Hashimoto W. Formation of a single polar flagellum by two distinct flagellar gene sets in Sphingomonas sp. strain A1. MICROBIOLOGY-SGM 2015; 161:1552-1560. [PMID: 26018545 DOI: 10.1099/mic.0.000119] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/02/2023]
Abstract
Gram-negative Sphingomonas sp. strain A1, originally identified as a non-motile and aflagellate bacterium, possesses two sets of genes required for flagellar formation. In this study, we characterized the flagellar genes and flagellum formation in strain A1. Flagellar gene cluster set I contained 35 flagellar genes, including one flagellin gene (p6), where the gene assembly structure resembled that required for the formation of lateral flagella in gammaproteobacteria. The set II flagellar genes were arranged in eight shorter clusters with 46 flagellar genes, including two flagellin genes (p5 and p5') and flhF, which is required for polar flagella. Our molecular phylogenetic analysis of the bacterial flagellins also demonstrated that, in contrast to p5 and p5', p6 was categorized as a lateral flagellin group. The motile phenotype appeared in strain A1 cells when they were subcultured on semisolid media. The motile strain A1 cells produced a single flagellum at the cell pole. DNA microarray analyses using non-motile and motile strain A1 cells indicated that flagellar formation was accompanied by increased transcription of both flagellar gene sets. The two flagellins p5 and p6 were major components of the flagellar filaments isolated from motile strain A1 cells, indicating that the polar flagellum is formed by lateral and non-lateral flagellins.
Collapse
Affiliation(s)
- Yukie Maruyama
- Division of Food Science and Biotechnology, Graduate School of Agriculture, Kyoto University, Uji, Kyoto 611-0011, Japan
| | - Masahiro Kobayashi
- Division of Food Science and Biotechnology, Graduate School of Agriculture, Kyoto University, Uji, Kyoto 611-0011, Japan
| | - Kousaku Murata
- Division of Food Science and Biotechnology, Graduate School of Agriculture, Kyoto University, Uji, Kyoto 611-0011, Japan
| | - Wataru Hashimoto
- Division of Food Science and Biotechnology, Graduate School of Agriculture, Kyoto University, Uji, Kyoto 611-0011, Japan
| |
Collapse
|
26
|
Abstract
Escherichia coli sequence type 131 (ST131) is a globally disseminated, multidrug resistant (MDR) clone responsible for a high proportion of urinary tract and bloodstream infections. The rapid emergence and successful spread of E. coli ST131 is strongly associated with several factors, including resistance to fluoroquinolones, high virulence gene content, the possession of the type 1 fimbriae FimH30 allele, and the production of the CTX-M-15 extended spectrum β-lactamase (ESBL). Here, we used genome sequencing to examine the molecular epidemiology of a collection of E. coli ST131 strains isolated from six distinct geographical locations across the world spanning 2000-2011. The global phylogeny of E. coli ST131, determined from whole-genome sequence data, revealed a single lineage of E. coli ST131 distinct from other extraintestinal E. coli strains within the B2 phylogroup. Three closely related E. coli ST131 sublineages were identified, with little association to geographic origin. The majority of single-nucleotide variants associated with each of the sublineages were due to recombination in regions adjacent to mobile genetic elements (MGEs). The most prevalent sublineage of ST131 strains was characterized by fluoroquinolone resistance, and a distinct virulence factor and MGE profile. Four different variants of the CTX-M ESBL-resistance gene were identified in our ST131 strains, with acquisition of CTX-M-15 representing a defining feature of a discrete but geographically dispersed ST131 sublineage. This study confirms the global dispersal of a single E. coli ST131 clone and demonstrates the role of MGEs and recombination in the evolution of this important MDR pathogen.
Collapse
|
27
|
Abstract
Aeromonas species are inhabitants of aquatic environments and are able to cause disease in humans and fish among other animals. In aquaculture, they are responsible for the economically important diseases of furunculosis and motile Aeromonas septicaemia (MAS). Whereas gastroenteritis and wound infections are the major human diseases associated with the genus. As they inhabit and survive in diverse environments, aeromonads possess a wide range of colonisation factors. The motile species are able to swim in liquid environments through the action of a single polar flagellum, the flagellin subunits of which are glycosylated; although essential for function the biological role of glycan addition is yet to be determined. Approximately 60% of aeromonads possess a second lateral flagella system that is expressed in viscous environments for swarming over surfaces; both flagellar systems have been shown to be important in the initial colonisation of surfaces. Subsequently, other non-flagellar colonisation factors are employed; these can be both filamentous and non-filamentous. The aeromonads possess a number of fimbrial systems with the bundle-forming MSHA type IV pilus system, having a major role in human cell adherence. Furthermore, a series of outer-membrane proteins have also been implicated in the aeromonad adhesion process. A number of strains are also capable of cell invasion and that maybe linked with the more invasive diseases of bacteraemia or wound infections. These strains employ cell surface factors that allow the colonisation of these niches that protect them from the host's immune system such as S-layers, capsules or particular lipopolysaccharides.
Collapse
Affiliation(s)
- Rebecca Lowry
- Department of Infection and Immunity, University of Sheffield, Sheffield, United Kingdom
| | - Sabela Balboa
- Department of Infection and Immunity, University of Sheffield, Sheffield, United Kingdom; Departamento de Microbiología y Parasitología, Universidad de Santiago de Compostela, Santiago de Compostela, Spain
| | - Jennifer L Parker
- Department of Infection and Immunity, University of Sheffield, Sheffield, United Kingdom
| | - Jonathan G Shaw
- Department of Infection and Immunity, University of Sheffield, Sheffield, United Kingdom.
| |
Collapse
|
28
|
Xu S, Peng Z, Cui B, Wang T, Song Y, Zhang L, Wei G, Wang Y, Shen X. FliS modulates FlgM activity by acting as a non-canonical chaperone to control late flagellar gene expression, motility and biofilm formation in Yersinia pseudotuberculosis. Environ Microbiol 2013; 16:1090-104. [PMID: 23957589 DOI: 10.1111/1462-2920.12222] [Citation(s) in RCA: 37] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/22/2013] [Accepted: 07/19/2013] [Indexed: 12/01/2022]
Abstract
The FlgM-FliA regulatory circuit plays a central role in coordinating bacterial flagellar assembly. In this study, we identified multiple novel binding partners of FlgM using bacterial two-hybrid screening. Among these binding partners, FliS, the secretion chaperone of the filament protein FliC, was identified to compete with FliA for the binding of FlgM. We further showed that by binding to FlgM, FliS protects it from secretion and degradation, thus maintaining an intracellular pool of FlgM reserved as the FliS-FlgM complex. Consequently, we found that the flagellar late-class promoter activities are significantly increased in the fliS deletion mutant. The fliS mutant is weakly motile and shows significantly increased biofilm formation on biotic surface. Based on the results obtained, we established for the first time the regulatory role of the flagellin chaperone FliS to fine-tune late flagellar assembly by modulating FlgM activity.
Collapse
Affiliation(s)
- Shengjuan Xu
- State Key Laboratory of Crop Stress Biology for Arid Areas and College of Life Sciences, Northwest A&F University, Yangling, Shaanxi, 712100, China; Wuhan Institute of Virology, Chinese Academy of Sciences, Wuhan, 430071, China
| | | | | | | | | | | | | | | | | |
Collapse
|
29
|
Evolution of pan-genomes of Escherichia coli, Shigella spp., and Salmonella enterica. J Bacteriol 2013; 195:2786-92. [PMID: 23585535 DOI: 10.1128/jb.02285-12] [Citation(s) in RCA: 79] [Impact Index Per Article: 7.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
Multiple sequencing of genomes belonging to a bacterial species allows one to analyze and compare statistics and dynamics of the gene complements of species, their pan-genomes. Here, we analyzed multiple genomes of Escherichia coli, Shigella spp., and Salmonella enterica. We demonstrate that the distribution of the number of genomes harboring a gene is well approximated by a sum of two power functions, describing frequent genes (present in many strains) and rare genes (present in few strains). The virtual absence of Shigella-specific genes not present in E. coli genomes confirms previous observations that Shigella is not an independent genus. While the pan-genome size is increasing with each new strain, the number of genes present in a fixed fraction of strains stabilizes quickly. For instance, slightly fewer than 4,000 genes are present in at least half of any group of E. coli genomes. Comparison of S. enterica and E. coli pan-genomes revealed the existence of a common periphery, that is, genes present in some but not all strains of both species. Analysis of phylogenetic trees demonstrates that rare genes from the periphery likely evolve under horizontal transfer, whereas frequent periphery genes may have been inherited from the periphery genome of the common ancestor.
Collapse
|
30
|
Abstract
Aeromonas hydrophila AH-3 lateral flagella are not assembled when bacteria grow in liquid media; however, lateral flagellar genes are transcribed. Our results indicate that A. hydrophila lateral flagellar genes are transcribed at three levels (class I to III genes) and share some similarities with, but have many important differences from, genes of Vibrio parahaemolyticus. A. hydrophila lateral flagellum class I gene transcription is σ(70) dependent, which is consistent with the fact that lateral flagellum is constitutively transcribed, in contrast to the characteristics of V. parahaemolyticus. The fact that multiple genes are included in class I highlights that lateral flagellar genes are less hierarchically transcribed than polar flagellum genes. The A. hydrophila lafK-fliEJL gene cluster (where the subscript L distinguishes genes for lateral flagella from those for polar flagella) is exclusively from class I and is in V. parahaemolyticus class I and II. Furthermore, the A. hydrophila flgAMNL cluster is not transcribed from the σ(54)/LafK-dependent promoter and does not contain class II genes. Here, we propose a gene transcriptional hierarchy for the A. hydrophila lateral flagella.
Collapse
|
31
|
Caffrey BE, Williams TA, Jiang X, Toft C, Hokamp K, Fares MA. Proteome-wide analysis of functional divergence in bacteria: exploring a host of ecological adaptations. PLoS One 2012; 7:e35659. [PMID: 22563391 PMCID: PMC3338524 DOI: 10.1371/journal.pone.0035659] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/10/2012] [Accepted: 03/21/2012] [Indexed: 12/31/2022] Open
Abstract
Functional divergence is the process by which new genes and functions originate through the modification of existing ones. Both genetic and environmental factors influence the evolution of new functions, including gene duplication or changes in the ecological requirements of an organism. Novel functions emerge at the expense of ancestral ones and are generally accompanied by changes in the selective forces at constrained protein regions. We present software capable of analyzing whole proteomes, identifying putative amino acid replacements leading to functional change in each protein and performing statistical tests on all tabulated data. We apply this method to 750 complete bacterial proteomes to identify high-level patterns of functional divergence and link these patterns to ecological adaptations. Proteome-wide analyses of functional divergence in bacteria with different ecologies reveal a separation between proteins involved in information processing (Ribosome biogenesis etc.) and those which are dependent on the environment (energy metabolism, defense etc.). We show that the evolution of pathogenic and symbiotic bacteria is constrained by their association with the host, and also identify unusual events of functional divergence even in well-studied bacteria such as Escherichia coli. We present a description of the roles of phylogeny and ecology in functional divergence at the level of entire proteomes in bacteria.
Collapse
Affiliation(s)
- Brian E. Caffrey
- Department of Genetics, University of Dublin, Trinity College, Dublin, Ireland
| | - Tom A. Williams
- Department of Genetics, University of Dublin, Trinity College, Dublin, Ireland
| | - Xiaowei Jiang
- Department of Genetics, University of Dublin, Trinity College, Dublin, Ireland
| | - Christina Toft
- Department of Molecular Evolution, Evolutionary Biology Centre, Uppsala University, Uppsala, Sweden
| | - Karsten Hokamp
- Department of Genetics, University of Dublin, Trinity College, Dublin, Ireland
| | - Mario A. Fares
- Department of Genetics, University of Dublin, Trinity College, Dublin, Ireland
- Integrative Systems Biology Group, Instituto de Biología Molecular y Celular de Plantas, CSIC-Universidad Politécnica de Valencia (UPV), Valencia, Spain
- * E-mail:
| |
Collapse
|
32
|
Bubendorfer S, Held S, Windel N, Paulick A, Klingl A, Thormann KM. Specificity of motor components in the dual flagellar system of Shewanella putrefaciens CN-32. Mol Microbiol 2011; 83:335-50. [PMID: 22151089 DOI: 10.1111/j.1365-2958.2011.07934.x] [Citation(s) in RCA: 42] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/14/2022]
Abstract
Bacterial flagellar motors are intricate nanomachines in which the stator units and rotor component FliM may be dynamically exchanged during function. Similar to other bacterial species, the gammaproteobacterium Shewanella putrefaciens CN-32 possesses a complete secondary flagellar system along with a corresponding stator unit. Expression of the secondary system occurs during planktonic growth in complex media and leads to the formation of a subpopulation with one or more additional flagella at random positions in addition to the primary polar system. We used physiological and phenotypic characterizations of defined mutants in concert with fluorescent microscopy on labelled components of the two different systems, the stator proteins PomB and MotB, the rotor components FliM(1) and FliM(2), and the auxiliary motor components MotX and MotY, to determine localization, function and dynamics of the proteins in the flagellar motors. The results demonstrate that the polar flagellum is driven by a Na(+)-dependent FliM(1)/PomAB/MotX/MotY flagellar motor while the secondary system is rotated by a H(+)-dependent FliM(2)/MotAB motor. The components were highly specific for their corresponding motor and are unlikely to be extensively swapped or shared between the two flagellar systems under planktonic conditions. The results have implications for both specificity and dynamics of flagellar motor components.
Collapse
Affiliation(s)
- Sebastian Bubendorfer
- Department of Ecophysiology, Max-Planck-Institut für terrestrische Mikrobiologie, Marburg, Germany
| | | | | | | | | | | |
Collapse
|
33
|
Escherichia Coli: From Genome Sequences to Consequences (or "Ceci n'est pas un éléphant..."). CANADIAN JOURNAL OF INFECTIOUS DISEASES & MEDICAL MICROBIOLOGY 2011; 17:114-6. [PMID: 18418485 DOI: 10.1155/2006/345319] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/28/2006] [Accepted: 02/28/2006] [Indexed: 01/18/2023]
Abstract
The present article summarizes a presentation given by Professor Mark Pallen of the School of Medicine at the University of Birmingham (Birmingham, United Kingdom) for the Fourth Stanier Lecture held in Regina, Saskatchewan, on November 9, 2004. Professor Pallen's lecture, entitled 'Escherichia coli: From genome sequences to consequences', provides a summary of the important discoveries of his team of research scientists in the area of genetic sequencing and variations in phenotypic expression.
Collapse
|
34
|
Petty NK, Feltwell T, Pickard D, Clare S, Toribio AL, Fookes M, Roberts K, Monson R, Nair S, Kingsley RA, Bulgin R, Wiles S, Goulding D, Keane T, Corton C, Lennard N, Harris D, Willey D, Rance R, Yu L, Choudhary JS, Churcher C, Quail MA, Parkhill J, Frankel G, Dougan G, Salmond GPC, Thomson NR. Citrobacter rodentium is an unstable pathogen showing evidence of significant genomic flux. PLoS Pathog 2011; 7:e1002018. [PMID: 21490962 PMCID: PMC3072379 DOI: 10.1371/journal.ppat.1002018] [Citation(s) in RCA: 30] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/11/2010] [Accepted: 02/18/2011] [Indexed: 11/18/2022] Open
Abstract
Citrobacter rodentium is a natural mouse pathogen that causes attaching and effacing (A/E) lesions. It shares a common virulence strategy with the clinically significant human A/E pathogens enteropathogenic E. coli (EPEC) and enterohaemorrhagic E. coli (EHEC) and is widely used to model this route of pathogenesis. We previously reported the complete genome sequence of C. rodentium ICC168, where we found that the genome displayed many characteristics of a newly evolved pathogen. In this study, through PFGE, sequencing of isolates showing variation, whole genome transcriptome analysis and examination of the mobile genetic elements, we found that, consistent with our previous hypothesis, the genome of C. rodentium is unstable as a result of repeat-mediated, large-scale genome recombination and because of active transposition of mobile genetic elements such as the prophages. We sequenced an additional C. rodentium strain, EX-33, to reveal that the reference strain ICC168 is representative of the species and that most of the inactivating mutations were common to both isolates and likely to have occurred early on in the evolution of this pathogen. We draw parallels with the evolution of other bacterial pathogens and conclude that C. rodentium is a recently evolved pathogen that may have emerged alongside the development of inbred mice as a model for human disease.
Collapse
Affiliation(s)
- Nicola K. Petty
- Wellcome Trust Sanger Institute, Wellcome
Trust Genome Campus, Hinxton, Cambridge, United Kingdom
- Department of Biochemistry, University of
Cambridge, Cambridge, United Kingdom
| | - Theresa Feltwell
- Wellcome Trust Sanger Institute, Wellcome
Trust Genome Campus, Hinxton, Cambridge, United Kingdom
| | - Derek Pickard
- Wellcome Trust Sanger Institute, Wellcome
Trust Genome Campus, Hinxton, Cambridge, United Kingdom
| | - Simon Clare
- Wellcome Trust Sanger Institute, Wellcome
Trust Genome Campus, Hinxton, Cambridge, United Kingdom
| | - Ana L. Toribio
- Wellcome Trust Sanger Institute, Wellcome
Trust Genome Campus, Hinxton, Cambridge, United Kingdom
| | - Maria Fookes
- Wellcome Trust Sanger Institute, Wellcome
Trust Genome Campus, Hinxton, Cambridge, United Kingdom
| | - Kevin Roberts
- Department of Biochemistry, University of
Cambridge, Cambridge, United Kingdom
| | - Rita Monson
- Department of Biochemistry, University of
Cambridge, Cambridge, United Kingdom
| | - Satheesh Nair
- Wellcome Trust Sanger Institute, Wellcome
Trust Genome Campus, Hinxton, Cambridge, United Kingdom
| | - Robert A. Kingsley
- Wellcome Trust Sanger Institute, Wellcome
Trust Genome Campus, Hinxton, Cambridge, United Kingdom
| | - Richard Bulgin
- Centre for Molecular Microbiology and
Infection, Division of Cell and Molecular Biology, Imperial College London,
London, United Kingdom
| | - Siouxsie Wiles
- Centre for Molecular Microbiology and
Infection, Division of Cell and Molecular Biology, Imperial College London,
London, United Kingdom
| | - David Goulding
- Wellcome Trust Sanger Institute, Wellcome
Trust Genome Campus, Hinxton, Cambridge, United Kingdom
| | - Thomas Keane
- Wellcome Trust Sanger Institute, Wellcome
Trust Genome Campus, Hinxton, Cambridge, United Kingdom
| | - Craig Corton
- Wellcome Trust Sanger Institute, Wellcome
Trust Genome Campus, Hinxton, Cambridge, United Kingdom
| | - Nicola Lennard
- Wellcome Trust Sanger Institute, Wellcome
Trust Genome Campus, Hinxton, Cambridge, United Kingdom
| | - David Harris
- Wellcome Trust Sanger Institute, Wellcome
Trust Genome Campus, Hinxton, Cambridge, United Kingdom
| | - David Willey
- Wellcome Trust Sanger Institute, Wellcome
Trust Genome Campus, Hinxton, Cambridge, United Kingdom
| | - Richard Rance
- Wellcome Trust Sanger Institute, Wellcome
Trust Genome Campus, Hinxton, Cambridge, United Kingdom
| | - Lu Yu
- Wellcome Trust Sanger Institute, Wellcome
Trust Genome Campus, Hinxton, Cambridge, United Kingdom
| | - Jyoti S. Choudhary
- Wellcome Trust Sanger Institute, Wellcome
Trust Genome Campus, Hinxton, Cambridge, United Kingdom
| | - Carol Churcher
- Wellcome Trust Sanger Institute, Wellcome
Trust Genome Campus, Hinxton, Cambridge, United Kingdom
| | - Michael A. Quail
- Wellcome Trust Sanger Institute, Wellcome
Trust Genome Campus, Hinxton, Cambridge, United Kingdom
| | - Julian Parkhill
- Wellcome Trust Sanger Institute, Wellcome
Trust Genome Campus, Hinxton, Cambridge, United Kingdom
| | - Gad Frankel
- Centre for Molecular Microbiology and
Infection, Division of Cell and Molecular Biology, Imperial College London,
London, United Kingdom
| | - Gordon Dougan
- Wellcome Trust Sanger Institute, Wellcome
Trust Genome Campus, Hinxton, Cambridge, United Kingdom
| | | | - Nicholas R. Thomson
- Wellcome Trust Sanger Institute, Wellcome
Trust Genome Campus, Hinxton, Cambridge, United Kingdom
| |
Collapse
|
35
|
Archer CT, Kim JF, Jeong H, Park JH, Vickers CE, Lee SY, Nielsen LK. The genome sequence of E. coli W (ATCC 9637): comparative genome analysis and an improved genome-scale reconstruction of E. coli. BMC Genomics 2011; 12:9. [PMID: 21208457 PMCID: PMC3032704 DOI: 10.1186/1471-2164-12-9] [Citation(s) in RCA: 126] [Impact Index Per Article: 9.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/26/2010] [Accepted: 01/06/2011] [Indexed: 01/21/2023] Open
Abstract
BACKGROUND Escherichia coli is a model prokaryote, an important pathogen, and a key organism for industrial biotechnology. E. coli W (ATCC 9637), one of four strains designated as safe for laboratory purposes, has not been sequenced. E. coli W is a fast-growing strain and is the only safe strain that can utilize sucrose as a carbon source. Lifecycle analysis has demonstrated that sucrose from sugarcane is a preferred carbon source for industrial bioprocesses. RESULTS We have sequenced and annotated the genome of E. coli W. The chromosome is 4,900,968 bp and encodes 4,764 ORFs. Two plasmids, pRK1 (102,536 bp) and pRK2 (5,360 bp), are also present. W has unique features relative to other sequenced laboratory strains (K-12, B and Crooks): it has a larger genome and belongs to phylogroup B1 rather than A. W also grows on a much broader range of carbon sources than does K-12. A genome-scale reconstruction was developed and validated in order to interrogate metabolic properties. CONCLUSIONS The genome of W is more similar to commensal and pathogenic B1 strains than phylogroup A strains, and therefore has greater utility for comparative analyses with these strains. W should therefore be the strain of choice, or 'type strain' for group B1 comparative analyses. The genome annotation and tools created here are expected to allow further utilization and development of E. coli W as an industrial organism for sucrose-based bioprocesses. Refinements in our E. coli metabolic reconstruction allow it to more accurately define E. coli metabolism relative to previous models.
Collapse
Affiliation(s)
- Colin T Archer
- Australian Institute for Bioengineering and Nanotechnology, Cnr Cooper and College Rds, The University of Queensland, St Lucia, Queensland 4072 Australia
| | - Jihyun F Kim
- Industrial Biotechnology and Bioenergy Research Center, Korea Research Institute of Bioscience and Biotechnology, 111 Gwahangno, Yuseong-gu, Daejeon, Korea
| | - Haeyoung Jeong
- Industrial Biotechnology and Bioenergy Research Center, Korea Research Institute of Bioscience and Biotechnology, 111 Gwahangno, Yuseong-gu, Daejeon, Korea
| | - Jin Hwan Park
- Department of Chemical and Biomolecular Engineering (BK21 program) and Center for Systems and Synthetic Biotechnology, Institute for the BioCentury, KAIST, 335 Gwahangno, Yuseong-gu, Daejeon 305-701, Republic of Korea
| | - Claudia E Vickers
- Australian Institute for Bioengineering and Nanotechnology, Cnr Cooper and College Rds, The University of Queensland, St Lucia, Queensland 4072 Australia
| | - Sang Yup Lee
- Department of Chemical and Biomolecular Engineering (BK21 program) and Center for Systems and Synthetic Biotechnology, Institute for the BioCentury, KAIST, 335 Gwahangno, Yuseong-gu, Daejeon 305-701, Republic of Korea
| | - Lars K Nielsen
- Australian Institute for Bioengineering and Nanotechnology, Cnr Cooper and College Rds, The University of Queensland, St Lucia, Queensland 4072 Australia
| |
Collapse
|
36
|
Anton L, Majander K, Savilahti H, Laakkonen L, Westerlund-Wikström B. Two distinct regions in the model protein Peb1 are critical for its heterologous transport out of Escherichia coli. Microb Cell Fact 2010; 9:97. [PMID: 21122159 PMCID: PMC3016274 DOI: 10.1186/1475-2859-9-97] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/01/2010] [Accepted: 12/02/2010] [Indexed: 12/20/2022] Open
Abstract
Background Escherichia coli is frequently the first-choice host organism in expression of heterologous recombinant proteins in basic research as well as in production of commercial, therapeutic polypeptides. Especially the secretion of proteins into the culture medium of E. coli is advantageous compared to intracellular production due to the ease in recovery of the recombinant protein. Since E. coli naturally is a poor secretor of proteins, a few strategies for optimization of extracellular secretion have been described. We have previously reported efficient secretion of the diagnostically interesting model protein Peb1 of Campylobacter jejuni into the growth medium of Escherichia coli strain MKS12 (ΔfliCfliD). To generate a more detailed understanding of the molecular mechanisms behind this interesting heterologous secretion system with biotechnological implications, we here analyzed further the transport of Peb1 in the E. coli host. Results When mature Peb1 was expressed without its SecA-YEG -dependent signal sequence and without the putative signal peptidase II recognition sequence in E. coli MKS111ΔHBB lacking the flagellar secretion complex, the protein was found in the periplasm and growth medium which indicated a flagellum-independent translocation. We assessed the Peb1 secretion proficiency by an exhaustive search for transport-affecting regions using a transposition-based scanning mutagenesis strategy. Strikingly, insertion mutagenesis of only two segments, called TAR1 (residues 42 and 43) and TAR2 (residues 173 to 180), prevented Peb1 secretion individually. We confirmed the importance of TAR regions by subsequent site-specific mutagenesis and verified that the secretion deficiency of Peb1 mutants was not due to insolubility or aggregation of the proteins in the cytoplasm. We found by cell fractionation that the mutant proteins were present in the periplasm as well as in the cytoplasm of MKS12. Hence, mutagenesis of TAR regions did not affect export of Peb1 across the cytoplasmic membrane, whereas its export over the outer membrane was markedly impaired. Conclusions We propose that the localization of the model protein Peb1 in the growth medium of E. coli is due to active secretion by a still unknown pathway of E. coli. The secretion apparently is a two-step process involving a periplasmic step and the TAR regions.
Collapse
Affiliation(s)
- Lena Anton
- Division of General Microbiology, Department of Biosciences, PO Box 56, FIN-00014 University of Helsinki, Helsinki, Finland
| | | | | | | | | |
Collapse
|
37
|
Ratiner YA, Sihvonen LM, Liu Y, Wang L, Siitonen A. Alteration of flagellar phenotype of Escherichia coli strain P12b, the standard type strain for flagellar antigen H17, possessing a new non-fliC flagellin gene flnA, and possible loss of original flagellar phenotype and genotype in the course of subculturing through semisolid media. Arch Microbiol 2010; 192:267-78. [PMID: 20174918 DOI: 10.1007/s00203-010-0556-x] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/03/2009] [Accepted: 02/03/2010] [Indexed: 11/30/2022]
Abstract
A practically important phenomenon, resulting in the loss of the original flagellar phenotype (genotype) of bacteria, is described in the Escherichia coli H17 type strain P12b possessing two distinct genes for H17 and H4 flagellins, respectively. By PCR, sequencing, and phylogenetic investigation, the H17 gene (originally expressed) was considered a new non-fliC flagellin gene and assigned flnA, while the H4 gene (originally cryptic) was reaffirmed as fliC. H17 and H4 flagella differed morphologically. The phenomenon consisted in the replacement of H17 cells by H4 cells during subculturing through certain semisolid media and resulted from the excision of flnA (H17) entirely or in part. The substitution rate depended on the density and nutrient composition of media and reached 100% even after a single passage through 0.3% LB agar. Such phenomenon can lead to an unexpected loss of original H17 phenotype. Our review of the literature showed that the loss of the original flagellar genotype (phenotype) of P12b has occurred in some laboratories while the authors continued to consider their cultures H17. We showed how to distinguish these alternative flagellin genotypes using popular fliC primers. Attention was also paid to possible discrepancies between serological and molecular results in flagellar typing of E. coli.
Collapse
Affiliation(s)
- Yuliy A Ratiner
- Department of Microbiology, Mechnikov Research Institute for Vaccines and Sera of The Russian Academy of Medical Sciences, Moscow, Russia.
| | | | | | | | | |
Collapse
|
38
|
Complete genome sequence and comparative metabolic profiling of the prototypical enteroaggregative Escherichia coli strain 042. PLoS One 2010; 5:e8801. [PMID: 20098708 PMCID: PMC2808357 DOI: 10.1371/journal.pone.0008801] [Citation(s) in RCA: 143] [Impact Index Per Article: 10.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/09/2009] [Accepted: 12/14/2009] [Indexed: 12/23/2022] Open
Abstract
BACKGROUND Escherichia coli can experience a multifaceted life, in some cases acting as a commensal while in other cases causing intestinal and/or extraintestinal disease. Several studies suggest enteroaggregative E. coli are the predominant cause of E. coli-mediated diarrhea in the developed world and are second only to Campylobacter sp. as a cause of bacterial-mediated diarrhea. Furthermore, enteroaggregative E. coli are a predominant cause of persistent diarrhea in the developing world where infection has been associated with malnourishment and growth retardation. METHODS In this study we determined the complete genomic sequence of E. coli 042, the prototypical member of the enteroaggregative E. coli, which has been shown to cause disease in volunteer studies. We performed genomic and phylogenetic comparisons with other E. coli strains revealing previously uncharacterised virulence factors including a variety of secreted proteins and a capsular polysaccharide biosynthetic locus. In addition, by using Biolog Phenotype Microarrays we have provided a full metabolic profiling of E. coli 042 and the non-pathogenic lab strain E. coli K-12. We have highlighted the genetic basis for many of the metabolic differences between E. coli 042 and E. coli K-12. CONCLUSION This study provides a genetic context for the vast amount of experimental and epidemiological data published thus far and provides a template for future diagnostic and intervention strategies.
Collapse
|
39
|
Farfán M, Miñana-Galbis D, Fusté MC, Lorén JG. Divergent evolution and purifying selection of the flaA gene sequences in Aeromonas. Biol Direct 2009; 4:23. [PMID: 19622168 PMCID: PMC2724415 DOI: 10.1186/1745-6150-4-23] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/15/2009] [Accepted: 07/21/2009] [Indexed: 11/10/2022] Open
Abstract
BACKGROUND The bacterial flagellum is the most important organelle of motility in bacteria and plays a key role in many bacterial lifestyles, including virulence. The flagellum also provides a paradigm of how hierarchical gene regulation, intricate protein-protein interactions and controlled protein secretion can result in the assembly of a complex multi-protein structure tightly orchestrated in time and space. As if to stress its importance, plants and animals produce receptors specifically dedicated to the recognition of flagella. Aside from motility, the flagellum also moonlights as an adhesion and has been adapted by humans as a tool for peptide display. Flagellar sequence variation constitutes a marker with widespread potential uses for studies of population genetics and phylogeny of bacterial species. RESULTS We sequenced the complete flagellin gene (flaA) in 18 different species and subspecies of Aeromonas. Sequences ranged in size from 870 (A. allosaccharophila) to 921 nucleotides (A. popoffii). The multiple alignment displayed 924 sites, 66 of which presented alignment gaps. The phylogenetic tree revealed the existence of two groups of species exhibiting different FlaA flagellins (FlaA1 and FlaA2). Maximum likelihood models of codon substitution were used to analyze flaA sequences. Likelihood ratio tests suggested a low variation in selective pressure among lineages, with an omega ratio of less than 1 indicating the presence of purifying selection in almost all cases. Only one site under potential diversifying selection was identified (isoleucine in position 179). However, 17 amino acid positions were inferred as sites that are likely to be under positive selection using the branch-site model. Ancestral reconstruction revealed that these 17 amino acids were among the amino acid changes detected in the ancestral sequence. CONCLUSION The models applied to our set of sequences allowed us to determine the possible evolutionary pathway followed by the flaA gene in Aeromonas, suggesting that this gene have probably been evolving independently in the two groups of Aeromonas species since the divergence of a distant common ancestor after one or several episodes of positive selection. REVIEWERS This article was reviewed by Alexey Kondrashov, John Logsdon and Olivier Tenaillon (nominated by Laurence D Hurst).
Collapse
Affiliation(s)
- Maribel Farfán
- Departament de Microbiologia i Parasitologia Sanitàries, Facultat de Farmàcia, Universitat de Barcelona, Av. Joan XXIII s/n, 08028 Barcelona, Spain.
| | | | | | | |
Collapse
|
40
|
Insights into the environmental resistance gene pool from the genome sequence of the multidrug-resistant environmental isolate Escherichia coli SMS-3-5. J Bacteriol 2008; 190:6779-94. [PMID: 18708504 DOI: 10.1128/jb.00661-08] [Citation(s) in RCA: 66] [Impact Index Per Article: 4.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
The increasing occurrence of multidrug-resistant pathogens of clinical and agricultural importance is a global public health concern. While antimicrobial use in human and veterinary medicine is known to contribute to the dissemination of antimicrobial resistance, the impact of microbial communities and mobile resistance genes from the environment in this process is not well understood. Isolated from an industrially polluted aquatic environment, Escherichia coli SMS-3-5 is resistant to a record number of antimicrobial compounds from all major classes, including two front-line fluoroquinolones (ciprofloxacin and moxifloxacin), and in many cases at record-high concentrations. To gain insights into antimicrobial resistance in environmental bacterial populations, the genome of E. coli SMS-3-5 was sequenced and compared to the genome sequences of other E. coli strains. In addition, selected genetic loci from E. coli SMS-3-5 predicted to be involved in antimicrobial resistance were phenotypically characterized. Using recombinant vector clones from shotgun sequencing libraries, resistance to tetracycline, streptomycin, and sulfonamide/trimethoprim was assigned to a single mosaic region on a 130-kb plasmid (pSMS35_130). The remaining plasmid backbone showed similarity to virulence plasmids from avian-pathogenic E. coli (APEC) strains. Individual resistance gene cassettes from pSMS35_130 are conserved among resistant bacterial isolates from multiple phylogenetic and geographic sources. Resistance to quinolones was assigned to several chromosomal loci, mostly encoding transport systems that are also present in susceptible E. coli isolates. Antimicrobial resistance in E. coli SMS-3-5 is therefore dependent both on determinants acquired from a mobile gene pool that is likely available to clinical and agricultural pathogens, as well, and on specifically adapted multidrug efflux systems. The association of antimicrobial resistance with APEC virulence genes on pSMS35_130 highlights the risk of promoting the spread of virulence through the extensive use of antibiotics.
Collapse
|
41
|
McQuiston JR, Fields PI, Tauxe RV, Logsdon JM. Do Salmonella carry spare tyres? Trends Microbiol 2008; 16:142-8. [PMID: 18375124 DOI: 10.1016/j.tim.2008.01.009] [Citation(s) in RCA: 32] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/18/2008] [Revised: 01/18/2008] [Accepted: 01/18/2008] [Indexed: 11/30/2022]
Abstract
Salmonellae are enterobacteria that have the unique ability to change their flagellar composition by switching expression among two loci that encode the major flagellin protein. This property is not available to all Salmonella, but is species, subspecies and serotype specific. Curiously, the subsequent loss of the second locus in some lineages of Salmonella has apparently been tolerated and, indeed, has led to considerable success for some lineages. We discuss here an evolutionary model for maintenance of this unique function and the possible evolutionary advantages of loss or preservation of this mechanism. We hypothesize that the second flagellin locus is a genetic 'spare tyre' used in particular environmental circumstances.
Collapse
Affiliation(s)
- John R McQuiston
- Graduate Program in Population Biology, Ecology and Evolution, Emory University, Atlanta, GA 30322, USA
| | | | | | | |
Collapse
|
42
|
Bresolin G, Trček J, Scherer S, Fuchs TM. Presence of a functional flagellar cluster Flag-2 and low-temperature expression of flagellar genes in Yersinia enterocolitica W22703. MICROBIOLOGY-SGM 2008; 154:196-206. [PMID: 18174138 DOI: 10.1099/mic.0.2007/008458-0] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/18/2022]
Abstract
Twelve Yersinia enterocolitica mutants carrying luxCDABE-transposon insertions in motility and chemotaxis genes were isolated on the basis of strong low-temperature induction. Two transposons were located within an 11.2 kb enteric flagellar cluster 2 (Flag-2) of Y. enterocolitica biotype 2, serotype O : 9 strain W22703. The Flag-2 gene cluster is absent from the corresponding genomic location of the sequenced strain Y. enterocolitica biotype 1B, serotype O : 8 strain 8081. Evidence for the functionality of the O : 9 Flag-2 genes, probably located within the plasticity zone of the genome, is provided by swarming assays. PCR analysis of 49 strains revealed the presence of Flag-2 genes in biotypes 2-5, but not in biotypes 1A or 1B. Bioluminescence, measured between 6 and 37 degrees C, showed that the expression of all genes located in Flag-2 and in the known flagellar cluster, Flag-1, was highest at approximately 20 degrees C, and that expression of two Flag-2 genes is FlhC-dependent. In a motility assay, a non-motile and a hyper-motile phenotype resulted from knockout mutations of the Flag-1 genes fliS1 and fliT, respectively. Complemented strains validated these results, confirming the regulatory role of FliT.
Collapse
Affiliation(s)
- Geraldine Bresolin
- Zentralinstitut für Ernährungs- und Lebensmittelforschung (ZIEL), Abteilung Mikrobiologie, Technische Universität München, Weihenstephaner Berg 3, 85354 Freising, Germany
| | - Janja Trček
- Zentralinstitut für Ernährungs- und Lebensmittelforschung (ZIEL), Abteilung Mikrobiologie, Technische Universität München, Weihenstephaner Berg 3, 85354 Freising, Germany
| | - Siegfried Scherer
- Zentralinstitut für Ernährungs- und Lebensmittelforschung (ZIEL), Abteilung Mikrobiologie, Technische Universität München, Weihenstephaner Berg 3, 85354 Freising, Germany
| | - Thilo M Fuchs
- Zentralinstitut für Ernährungs- und Lebensmittelforschung (ZIEL), Abteilung Mikrobiologie, Technische Universität München, Weihenstephaner Berg 3, 85354 Freising, Germany
| |
Collapse
|
43
|
Yen YT, Bhattacharya M, Stathopoulos C. Genome-widein silicomapping of the secretome in pathogenicYersinia pestisKIM. FEMS Microbiol Lett 2008; 279:56-63. [DOI: 10.1111/j.1574-6968.2007.01008.x] [Citation(s) in RCA: 15] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/22/2023] Open
|
44
|
Flagellin-dependent and -independent inflammatory responses following infection by enteropathogenic Escherichia coli and Citrobacter rodentium. Infect Immun 2008; 76:1410-22. [PMID: 18227166 DOI: 10.1128/iai.01141-07] [Citation(s) in RCA: 62] [Impact Index Per Article: 3.9] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/31/2022] Open
Abstract
Enteropathogenic Escherichia coli (EPEC) and the murine pathogen Citrobacter rodentium belong to the attaching and effacing (A/E) family of bacterial pathogens. These noninvasive bacteria infect intestinal enterocytes using a type 3 secretion system (T3SS), leading to diarrheal disease and intestinal inflammation. While flagellin, the secreted product of the EPEC fliC gene, causes the release of interleukin 8 (IL-8) from epithelial cells, it is unclear whether A/E bacteria also trigger epithelial inflammatory responses that are FliC independent. The aims of this study were to characterize the FliC dependence or independence of epithelial inflammatory responses to direct infection by EPEC or C. rodentium. Following infection of Caco-2 intestinal epithelial cells by wild-type and DeltafliC EPEC, a rapid activation of several proinflammatory genes, including those encoding IL-8, monocyte chemoattractant protein 1, macrophage inflammatory protein 3alpha (MIP3alpha), and beta-defensin 2, occurred in a FliC-dependent manner. These responses were accompanied by mitogen-activated protein kinase activation, as well as the Toll-like receptor 5 (TLR5)-dependent activation of NF-kappaB. At later infection time points, a subset of these proinflammatory genes (IL-8 and MIP3alpha) was also induced in cells infected with DeltafliC EPEC. The nonmotile A/E pathogen C. rodentium also triggered similar innate responses through a TLR5-independent but partially NF-kappaB-dependent mechanism. Moreover, the EPEC FliC-independent responses were increased in the absence of the locus of enterocyte effacement-encoded T3SS, suggesting that translocated bacterial effectors suppress rather than cause the FliC-independent inflammatory response. Thus, we demonstrate that infection of intestinal epithelial cells by A/E pathogens can trigger an array of proinflammatory responses from epithelial cells through both FliC-dependent and -independent pathways, expanding our understanding of the innate epithelial response to infection by these pathogens.
Collapse
|
45
|
Abstract
Genomes from all of the crucial bacterial pathogens of humans, plants and animals have now been sequenced, as have genomes from many of the important commensal, symbiotic and environmental microorganisms. Analysis of these sequences has revealed the forces that shape pathogen evolution and has brought to light unexpected aspects of pathogen biology. The finding that horizontal gene transfer and genome decay have key roles in the evolution of bacterial pathogens was particularly surprising. It has also become evident that even the definitions for 'pathogen' and 'virulence factor' need to be re-evaluated.
Collapse
|
46
|
Thomson NR, Howard S, Wren BW, Holden MTG, Crossman L, Challis GL, Churcher C, Mungall K, Brooks K, Chillingworth T, Feltwell T, Abdellah Z, Hauser H, Jagels K, Maddison M, Moule S, Sanders M, Whitehead S, Quail MA, Dougan G, Parkhill J, Prentice MB. The complete genome sequence and comparative genome analysis of the high pathogenicity Yersinia enterocolitica strain 8081. PLoS Genet 2007; 2:e206. [PMID: 17173484 PMCID: PMC1698947 DOI: 10.1371/journal.pgen.0020206] [Citation(s) in RCA: 168] [Impact Index Per Article: 9.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/14/2006] [Accepted: 10/20/2006] [Indexed: 11/19/2022] Open
Abstract
The human enteropathogen, Yersinia enterocolitica, is a significant link in the range of Yersinia pathologies extending from mild gastroenteritis to bubonic plague. Comparison at the genomic level is a key step in our understanding of the genetic basis for this pathogenicity spectrum. Here we report the genome of Y. enterocolitica strain 8081 (serotype 0:8; biotype 1B) and extensive microarray data relating to the genetic diversity of the Y. enterocolitica species. Our analysis reveals that the genome of Y. enterocolitica strain 8081 is a patchwork of horizontally acquired genetic loci, including a plasticity zone of 199 kb containing an extraordinarily high density of virulence genes. Microarray analysis has provided insights into species-specific Y. enterocolitica gene functions and the intraspecies differences between the high, low, and nonpathogenic Y. enterocolitica biotypes. Through comparative genome sequence analysis we provide new information on the evolution of the Yersinia. We identify numerous loci that represent ancestral clusters of genes potentially important in enteric survival and pathogenesis, which have been lost or are in the process of being lost, in the other sequenced Yersinia lineages. Our analysis also highlights large metabolic operons in Y. enterocolitica that are absent in the related enteropathogen, Yersinia pseudotuberculosis, indicating major differences in niche and nutrients used within the mammalian gut. These include clusters directing, the production of hydrogenases, tetrathionate respiration, cobalamin synthesis, and propanediol utilisation. Along with ancestral gene clusters, the genome of Y. enterocolitica has revealed species-specific and enteropathogen-specific loci. This has provided important insights into the pathology of this bacterium and, more broadly, into the evolution of the genus. Moreover, wider investigations looking at the patterns of gene loss and gain in the Yersinia have highlighted common themes in the genome evolution of other human enteropathogens. The goal of this study was to catalogue all the genes encoded within the Y. enterocolitica genome to help us better understand how this bacterium and related bacteria cause different diseases. There are currently genome sequences (complete gene catalogues) available for two other members of this bacterial lineage, which cause dramatically different diseases: Y. pseudotuberculosis, like Y. enterocolitica, is a gut pathogen (enteropathogen) causing gastroenteritis in humans and animals. Yersinia pestis mostly resides within blood (circulating or in fleas following blood meals) and lymph tissue. It causes bubonic plague in humans and animals, and is historically known as “The Black Death.” A three-way comparison of these genomes revealed a patchwork of genes we have defined as being species- or disease-specific and genes that are common to all three Yersinia species. This has provided us with important information on shared gene functions that define the two enteropathogenic yersinias and those that differentiate them. This will help us to connect what we know about the Y. enterocolitica lifestyle within the gut to the disease it causes and its genetic makeup. We have also provided further evidence of gene-loss by Y. pestis as it has evolved from Y. pseudotuberculosis into a more acute systemic pathogen. Similar patterns of gene loss are seen in other important pathogens such as Salmonella enterica serovar Typhi.
Collapse
Affiliation(s)
- Nicholas R Thomson
- The Pathogen Sequencing Unit, The Wellcome Trust Sanger Institute, Wellcome Trust Genome Campus, Hinxton, Cambridge, United Kingdom.
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | |
Collapse
|
47
|
Abstract
Forty-one flagellated species representing 11 bacterial phyla were used to investigate the origin of secondary flagellar systems and the structure and formation of flagellar gene operons over the course of bacterial evolution. Secondary (i.e., lateral) flagellar systems, which are harbored by five of the proteobacterial species considered, originated twice, once in the alphaproteobacterial lineage and again in the common ancestor of the Beta- and Gammaproteobacteria. The order and organization of flagellar genes have undergone extensive shuffling and rearrangement among lineages, and based on the phylogenetic distributions of flagellar gene complexes, the flagellar gene operons existed as small, usually two-gene units in the ancestor of Bacteria and have expanded through the recruitment of new genes and fusion of gene units. In contrast to the evolutionary trend towards larger flagellar gene complexes, operon structures have been highly disrupted through gene disassociation and rearrangements in the Epsilon- and Alphaproteobacteria. These results demonstrate that the genetic basis of this ancient and structurally conserved organelle has been subject to many lineage-specific modifications.
Collapse
Affiliation(s)
- Renyi Liu
- Department of Biochemistry & Molecular Biophysics, University of Arizona, Tucson, AZ 85721, USA
| | | |
Collapse
|
48
|
Dirk LMA, Trievel RC, Houtz RL. 7 Non-histone protein lysine methyltransferases: Structure and catalytic roles. Enzymes 2007; 24:179-228. [PMID: 26718041 DOI: 10.1016/s1874-6047(06)80009-0] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/23/2022]
Abstract
Non-histone protein lysine methyltransferases (PKMTs) represent an exceptionally diverse and large group of PKMTs. Even accepting the possibility of multiple protein substrates, if the number of different proteins with methylated lysyl residues and the number of residues modified is indicative of individual PKMTs there are well over a hundred uncharacterized PKMTs. Astoundingly, only a handful of PKMTs have been studied, and of these only a few with identifiable and well-characterized structure and biochemical properties. Four representative PKMTs responsible for trimethyllysyl residues in ribosomal protein LI 1, calmodulin, cytochrome c, and Rubisco are herein examined for enzymological properties, polypeptide substrate specificity, functional significance, and structural characteristics. Although representative of non-histone PKMTs, and enzymes for whichcollectively there is a large amount of information, individually each of the PKMTs discussed in this chapter suffers from a lack of at least some critical information. Other than the obvious commonality in the AdoMet substrate cofactor and methyl group transfer, these enzymes do not have common structural features, polypeptide substrate specificity, or protein sequence. However, there may be a commonality that supports the hypothesis that methylated lysyl residues act as global determinants regulating specific protein-protein interactions.
Collapse
Affiliation(s)
- Lynnette M A Dirk
- Department of Horticulture University of Kentucky 407 Plant Science Building Lexington, KY 40546, USA
| | - Raymond C Trievel
- Department of Biological Chemistry University of Michigan Medical School Medical Science Building 1 Ann Arbor, MI 48109, USA
| | - Robert L Houtz
- Department of Horticulture University of Kentucky 407 Plant Science Building Lexington, KY 40546, USA
| |
Collapse
|
49
|
Hobman JL, Penn CW, Pallen MJ. Laboratory strains of Escherichia coli: model citizens or deceitful delinquents growing old disgracefully? Mol Microbiol 2007; 64:881-5. [PMID: 17501914 DOI: 10.1111/j.1365-2958.2007.05710.x] [Citation(s) in RCA: 55] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/17/2023]
Abstract
Escherichia coli stands unchallenged as biology's premier model organism. However, we propose, equipped with insights from the post-genomic era, a contrary view: that microbiology's chief idol has feet of clay. E. coli laboratory strains, particularly E. coli K-12, are far from model citizens, but instead degenerate and deceitful delinquents growing old disgracefully in our scientific institutions. E. coli K-12 is neither archetype nor ancestor. In addition, it has a far from optimal provenance for a model organism, with strong grounds for believing that current versions of the strain are quite distinct from any original wild-type free-living ancestor. In addition, it is usually studied under conditions far removed from its natural habitats and in ignorance of the selective pressures that have shaped its evolution. Fortunately, a flood of information from high-throughput genome sequencing, together with a new 'eco-evo' view of this model organism, promises to help put K-12 better into context.
Collapse
Affiliation(s)
- Jon L Hobman
- School of Biosciences, The Medical School, The University of Birmingham, Edgbaston, Birmingham, UK
| | | | | |
Collapse
|
50
|
Canals R, Vilches S, Wilhelms M, Shaw JG, Merino S, Tomás JM. Non-structural flagella genes affecting both polar and lateral flagella-mediated motility in Aeromonas hydrophila. Microbiology (Reading) 2007; 153:1165-1175. [PMID: 17379726 DOI: 10.1099/mic.0.2006/000687-0] [Citation(s) in RCA: 31] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022] Open
Abstract
An Aeromonas hydrophila AH-3 miniTn5 mutant unable to produce polar and lateral flagella was isolated, in which the transposon was inserted into a gene whose encoded protein was an orthologue of the Campylobacter jejuni motility accessory factor (Maf) protein. In addition to this gene, several other related genes were found in this cluster that was adjacent to the region 2 genes of the polar flagellum. Mutation of the A. hydrophila AH-3 maf-2, neuB-like, flmD or neuA-like genes resulted in non-motile cells that were unable to swim or swarm due to the absence of both polar and lateral flagella. However, both polar and lateral flagellins were present but were unglycosylated. Although the A. hydrophila AH-3 or Aeromonas caviae Sch3N genes did not hybridize with each other at the nucleotide level, the gene products were able to fully complement the mutations in either bacterium. Furthermore, well-characterized C. jejuni genes involved in flagella glycosylation (Cj1293, -1294 and -1317) were fully able to complement A. hydrophila mutants in the corresponding genes (flmA, flmB and neuB-like). It was concluded that the maf-2, neuB-like, flmD and neuA-like genes are involved in the glycosylation of both the polar and the lateral flagella in Aeromonas strains.
Collapse
Affiliation(s)
- Rocío Canals
- Departamento de Microbiología, Facultad de Biología, Universidad de Barcelona, Diagonal 645, 08071 Barcelona, Spain
| | - Silvia Vilches
- Departamento de Microbiología, Facultad de Biología, Universidad de Barcelona, Diagonal 645, 08071 Barcelona, Spain
| | - Markus Wilhelms
- Departamento de Microbiología, Facultad de Biología, Universidad de Barcelona, Diagonal 645, 08071 Barcelona, Spain
| | - Jonathan G Shaw
- Division of Molecular and Genetic Medicine, University of Sheffield Medical School, Sheffield S10 2RX, UK
| | - Susana Merino
- Departamento de Microbiología, Facultad de Biología, Universidad de Barcelona, Diagonal 645, 08071 Barcelona, Spain
| | - Juan M Tomás
- Departamento de Microbiología, Facultad de Biología, Universidad de Barcelona, Diagonal 645, 08071 Barcelona, Spain
| |
Collapse
|