Advances in Bacterial Pathogen Biology

1. Auflage 2014
ISBN: 978-0-12-800305-3
Verlag: Elsevier Science & Techn.
Format: EPUB
Kopierschutz: 6 - ePub Watermark

E-Book, Englisch, Band Volume 65, 448 Seiten

Reihe: Advances in Microbial Physiology

This volume is an up-to-date overview of the physiology of selected pathogenic bacteria. Each chapter is written by experts in the field of that organism.The focus is on biochemistry and physiology but topics of clinical relevance are included. - Contributions from leading authorities - Informs and updates on all the latest developments in the field

Autoren/Hrsg.

Inhaltsverzeichnis

1;Front Cover;1
2;Advances in Bacterial Pathogen
Biology;4
3;Copyright;5
4;Contents;6
5;Contributors;10
6;Chapter One: Energetics of Pathogenic Bacteria and Opportunities for Drug Development;12
6.1;1. Introduction;13
6.2;2. Bacterial Energetics as a Target Space for Drug Development;13
6.2.1;2.1. Generation of the proton motive force: An essential property of all bacterial cells;14
6.2.2;2.2. Diversity and flexibility of electron transport chains in bacteria;16
6.2.3;2.3. Primary respiratory dehydrogenases;18
6.2.3.1;2.3.1. NADH dehydrogenases: The roles of bacterial NDH-1 and NDH-2;18
6.2.3.2;2.3.2. Succinate dehydrogenase: Enzyme variation and essentiality in bacterial pathogens;23
6.2.3.3;2.3.3. Formate dehydrogenase: A major electron donor for anaerobic respiratory chains;25
6.2.3.4;2.3.4. Hydrogenase: Consuming a dependable reduced gas;26
6.2.4;2.4. Terminal respiratory reductases;29
6.2.4.1;2.4.1. Haem-copper terminal oxidases: Proton translocation at a range of oxygen partial pressures;29
6.2.4.2;2.4.2. Cytochrome bd oxidase: A bacterial-specific next-generation drug target;32
6.2.4.3;2.4.3. Respiratory nitrate and nitrite reductases: Exploiting host immune defences;36
6.2.4.4;2.4.4. Fumarate reductase: Anaerobic respiration using an endogenous electron acceptor;40
6.2.4.5;2.4.5. Tetrathionate reductase and other alternative reductases: Emerging roles in host colonisation;42
6.2.5;2.5. Generators of sodium motive force in bacterial pathogens;43
6.2.6;2.6. ATP homeostasis and the F1Fo-ATP synthase: A clinically approved drug target;46
6.3;3. Conclusions and Future Perspectives;51
6.4;Acknowledgements;54
6.5;References;55
7;Chapter Two: The Impact of Horizontal Gene Transfer on the Biology of Clostridium difficile;74
7.1;1. Introduction to Clostridium difficile and CDI;75
7.2;2. Introns;76
7.3;3. IStrons;77
7.4;4. Mobilisable Transposons;78
7.5;5. Conjugative Transposons;80
7.5.1;5.1. Tn916-like elements;81
7.5.2;5.2. Tn1549-like elements;82
7.6;6. Other Integrative MGEs in C. difficile;84
7.7;7. The skinCd Element;84
7.8;8. Bacteriophages;85
7.9;9. Transfer of the PaLoc;86
7.10;10. Conclusions;89
7.11;References;90
8;Chapter Three: Metal Ion Homeostasis in Listeria monocytogenes and Importance in Host-Pathogen Interactions;94
8.1;1. Introduction;95
8.2;2. Overview of Listeria monocytogenes Disease Progression;97
8.2.1;2.1. The intracellular life cycle of L. monocytogenes;98
8.3;3. Control of Metal Levels in Bacteria;100
8.4;4. L. monocytogenes and Zinc;101
8.4.1;4.1. Zinc availability within the host;102
8.4.1.1;4.1.1. Extracellular zinc chelation;104
8.4.1.2;4.1.2. Control of intracellular zinc availability;105
8.4.2;4.2. Zinc sensing and homeostasis in L. monocytogenes;107
8.4.2.1;4.2.1. The Zur regulon;107
8.4.2.2;4.2.2. Zinc import by the ZurLAM and ZinABC systems;111
8.4.2.3;4.2.3. Other proteins with a role in zinc import;113
8.4.2.4;4.2.4. The response to elevated zinc and zinc export;114
8.5;5. L. monocytogenes and Copper;115
8.5.1;5.1. Exploiting the microbicidal activity of copper in host immune defences;116
8.5.2;5.2. Copper sensing and homeostasis in L. monocytogenes;118
8.5.2.1;5.2.1. Copper efflux mediated by the csoR-copA-copZ operon;120
8.6;6. Concluding Remarks;122
8.7;References;123
9;Chapter Four: The Role of Macrophages in the Innate Immune Response to Streptococcus pneumoniae and Staphylococcus aureus: M...;136
9.1;1. Introduction;137
9.2;2. S. pneumoniae Virulence Factors Impede Phagocytosis and Its Consequences;140
9.3;3. S. aureus Virulence Factors Subvert Multiple Innate Immune Responses Including Intracellular Killing;144
9.4;4. Origins of Macrophages;149
9.5;5. The Spectrum of Macrophage Activation;151
9.6;6. Epigenetic Regulation of Macrophage Function;155
9.7;7. Mechanisms of Macrophage Phagocytosis;164
9.8;8. Phagocytosis of S. pneumoniae and S. aureus;166
9.9;9. Intracellular Localisation of Bacteria;171
9.10;10. Microbial Killing by Macrophages;173
9.11;11. Apoptosis-Associated Killing Complements Clearance of S. pneumoniae;176
9.12;12. Macrophage Killing of S. aureus;180
9.13;13. Macrophage Orchestration of the Inflammatory Response;182
9.14;14. Pattern Recognition Receptors in the Recognition of S. pneumoniae and S. aureus;185
9.15;15. Conclusion;189
9.16;References;190
10;Chapter Five: Aeromonas Flagella and Colonisation Mechanisms;214
10.1;1. Introduction;215
10.2;2. Flagella;217
10.2.1;2.1. Polar flagella;217
10.2.2;2.2. Flagellin glycosylation;220
10.2.3;2.3. Lateral flagella;223
10.2.4;2.4. Genetic organisation and regulation of the Aeromonas flagella systems;225
10.2.4.1;2.4.1. Polar flagella regulation;225
10.2.4.2;2.4.2. Lateral flagella;226
10.2.4.3;2.4.3. Regulation of flagella expression;227
10.2.4.4;2.4.4. Regulation of the flagella systems by c-di-GMP;231
10.3;3. Lipopolysaccharide and Capsules;234
10.3.1;3.1. Lipopolysaccharide;234
10.3.2;3.2. Capsules;237
10.4;4. Pili;239
10.5;5. Outer-Membrane Proteins and S-Layer;242
10.5.1;5.1. Outer-membrane proteins;242
10.5.2;5.2. S-layer;245
10.6;6. Aeromonad Colonisation and Host Response;247
10.6.1;6.1. Adherence factors;247
10.6.2;6.2. Secreted factors;250
10.6.3;6.3. Host relationships;252
10.7;7. Conclusions and Outlook;253
10.8;References;257
11;Chapter Six: Physiological Adaptations of Key Oral Bacteria;268
11.1;1. Introduction;269
11.2;2. Key Oral Environmental Niches;269
11.2.1;2.1. External solid surfaces of the tooth;270
11.2.2;2.2. Internal tooth structures and niches;272
11.2.3;2.3. Life below the gum line;272
11.3;3. The Major Infections of the Oral Cavity;274
11.3.1;3.1. Caries: microbial involvement and aetiology;274
11.3.2;3.2. Pulp and periapical infection;279
11.3.2.1;3.2.1. Microbial aetiology of pulp infections;284
11.3.3;3.3. Gum disease: gingivitis and periodontitis;285
11.3.4;3.4. Microbial aetiology of gingivitis and periodontitis;287
11.4;4. Bacterial Adaptations in the Oral Cavity;289
11.4.1;4.1. Nutritional adaptations to life at the host-pathogen interface;289
11.4.1.1;4.1.1. Adaptation to a proteolytic lifestyle;289
11.4.1.2;4.1.2. Exploitation of the host glycome as a nutritional interface;291
11.4.1.2.1;4.1.2.1. Exploitation of host-derived sialic acid;292
11.4.1.2.2;4.1.2.2. The role of other glycosidases in oral bacteria;301
11.4.2;4.2. Protein secretion in the oral context;303
11.5;5. Surface Adhesins as Colonisation Factors of Oral Bacteria;310
11.5.1;5.1. Attachment to hard tissues;311
11.5.2;5.2. Interbacterial attachments;312
11.5.3;5.3. Attachment to host cell surfaces;316
11.6;6. Stress Responses of Import in Colonisation and Infection by Oral Bacteria;320
11.7;7. Summary and Future Perspectives;323
11.8;Acknowledgements;324
11.9;References;324
12;Chapter Seven: Virulence Factors of Uropathogenic E. coli and Their Interaction with the Host;348
12.1;1. Introduction;349
12.2;2. Pathogenesis of Urinary Tract Infection;350
12.3;3. Adhesins;353
12.3.1;3.1. Type 1 fimbriae;354
12.3.2;3.2. P fimbriae;355
12.3.3;3.3. Curli fimbriae;356
12.3.4;3.4. Afa/Dr adhesins;357
12.3.5;3.5. F1C/S fimbriae;359
12.3.6;3.6. F9 and type 3 fimbriae;359
12.3.7;3.7. Antigen 43;360
12.3.8;3.8. Uropathogenic E. coli autotransporter;361
12.4;4. Toxins;361
12.4.1;4.1. Endotoxin;361
12.4.2;4.2. a-Haemolysin;362
12.4.3;4.3. Cytotoxic necrotising factor 1;363
12.4.4;4.4. Serine protease autotransporters of the Enterobacteriaceae;364
12.5;5. Iron-Acquisition Systems;364
12.5.1;5.1. Haem receptors ChuA and Hma;365
12.5.2;5.2. Siderophores;365
12.6;6. Immune Evasion Mechanisms;366
12.6.1;6.1. Immune suppression;367
12.6.2;6.2. Serum resistance and protection against phagocytes;367
12.6.3;6.3. Biofilm formation and extracellular matrix components;368
12.7;7. Conclusion;369
12.8;References;370
13;Author Index;384
14;Subject Index;442

Leseproben

Chapter Two The Impact of Horizontal Gene Transfer on the Biology of Clostridium difficile
Adam P. Roberts1; Elaine Allan; Peter Mullany    Department of Microbial Diseases, UCL Eastman Dental Institute, University College London, London, United Kingdom
1 Corresponding author: email address: [e-mail] Abstract
Clostridium difficile infection (CDI) is now recognised as the main cause of healthcare associated diarrhoea. Over the recent years there has been a change in the epidemiology of CDI with certain related strains dominating infection. These strains have been termed hyper-virulent and have successfully spread across the globe. Many C. difficile strains have had their genomes completely sequenced allowing researchers to build up a very detailed picture of the contribution of horizontal gene transfer to the adaptive potential, through the acquisition of mobile DNA, of this organism. Here, we review and discuss the contribution of mobile genetic elements to the biology of this clinically important pathogen. Keywords Clostridium difficile Horizontal gene transfer Mobile genetic elements Transposon Conjugative transposon Mobilisable transposon Bacteriophage PaLoc 1 Introduction to Clostridium difficile and CDI
Clostridium difficile is an anaerobic, Gram-positive, endospore-forming, motile, rod-shaped bacterium which was originally isolated from the stool of a healthy infant (Hall & O’Toole, 1935). It is responsible for the disease in many different animals including economically important food animals, such as pigs (Songer, 2004), companion animals, such as dogs (Keel, Brazier, Post, Weese, & Songer, 2007), and humans (Arroyo et al., 2005). The past decade has seen the emergence of strains of the hyper-virulent PCR ribotype 027 complex, which is associated with increased incidence and severity of disease. CDI caused by other important ribotypes, including 017, 023, 078, has also increased (Barbut, Jones, & Eckert, 2011). C. difficile causes toxin-mediated gastrointestinal diseases ranging from mild, self-limiting diarrhoea to life threatening, and sometimes fatal, pseudomembranous colitis, and toxic megacolon (Norén, 2010; Rupnik, Wilcox, & Gerding, 2009). The main virulence factors of C. difficile are the toxins A and B, designated TcdA and TcdB, respectively, which glycosylate Rho family proteins within host cells and lead to depolymerisation of the actin cytoskeleton. The toxin genes, tcdA and tcdB, are both located on the 19-kb pathogenicity locus, PaLoc (Braun, Hundsberger, Leukel, Sauerborn, & von Eichel-Streiber, 1996) which encodes three other proteins; the sigma factor, TcdR, which positively regulates the expression of tcdA and tcdB, TcdE which is related to bacteriophage holin proteins, and TcdC which was thought to be a negative regulator (anti-sigma factor) of toxin production although more recent studies have cast doubt on this role (Bakker, Smits, Kuijper, & Corver, 2012). In addition to the PaLoc-encoded toxins, some C. difficile strains produce a third toxin called the binary toxin (designated cytolethal distending toxin, CDT), which also acts by actin modification (Gerding, Johnson, Rupnik, & Aktories, 2014). The exact role of each of the toxins in CDI remains the subject of debate as strains are isolated from CDI patients carrying different genetic variations and combinations of the three genes (Dingle et al., 2011). Furthermore, mutational analysis of the toxin genes has been carried out by different groups using different experimental strategies and different descendants of the same strain, potentially contributing to conflicting results about the exact role each toxin plays in pathogenesis (Kuehne et al., 2010; Lyras et al., 2009). CDI usually follows exposure of the patient to antimicrobial therapy which disrupts the intestinal microbiota sufficiently to destroy its protective colonisation resistance and allows environmentally acquired C. difficile spores to germinate and colonise the colon. There are multiple groups of related C. difficile strains, known as ribotypes, responsible for CDI which are grouped according to the sequence similarities between the 16S and 23S rDNA intergenic regions. Certain PCR ribotypes have emerged as hyper-virulent, e.g., 027 and 078. As well as hyper-virulence, another emerging property of C. difficile is resistance to antibiotics, many of which have been acquired on MGEs (Rupnik et al., 2009; Smits, 2013). Integrated mobile genetic elements, as opposed to self-replicating plasmids, can cause heritable changes to the host in multiple ways. They can cause mutations simply by disrupting the genes at their target site upon insertion and they can form gene fusions upon insertion as seen for the conjugative transposon CTn5 in strain 630 (Sebaihia et al., 2006). Introduction of foreign DNA, from the previous host, can occur upon transfer and removal of host DNA upon excision is also possible. Various mobile elements have been shown to undergo inversion reactions within their target site (e.g., O'Keeffe, Hill, & Ross, 1999) and this can cause both upstream and downstream polar effects resulting from interrupted transcription from the host across the insertion site and differing expression levels resulting from MGE originating transcripts reading out of the MGE into the host genome. Polar effects also occur following insertion into a new site. There are also instances of deletion events leaving part of an MGE isolated, and fixed, in the host's chromosome. Furthermore, there are examples where interactions between different MGEs result in trans-activation of elements due to the activity of another, e.g., high frequency recombination of the genome due to activation of an oriT located in a chromosomal copy of a conjugative element. Highly related MGEs are common within C. difficile genomes and exhibit variation in structure and properties, which allow them to be grouped into families (discussed below). Because of the variety of MGEs apparent in the hundreds of C. difficile genome sequences available, a detailed description of each element will not be provided but representatives from each different group will be discussed. The individual families of MGEs commonly found in C. difficile are ordered according to increasing genetic complexity with the “simplest” MGEs discussed first. 2 Introns
Introns were first discovered in eukaryotes and are ubiquitous in higher eukaryotes such as humans. In prokaryotes, some introns are capable of transposition and are often associated with other MGEs such as conjugative transposons and conjugative plasmids. Introns are classified into either group one (I) or two (II) according to their highly conserved secondary structure (Belfort & Perlman, 1995). Group II introns have six conserved helices which emanate from a central wheel. This secondary structure is required for splicing. In one of the conserved helix (number IV), there is often an ORF encoding a multifunctional protein which has a reverse transcriptase domain which, as part of a riboprotein complex, can catalyse transposition of the intron to an allelic site via retrohoming or transposition to a different site (Belfort & Perlman, 1995). In C. difficile, there is a group II intron inserted into the conjugative transposon, Tn5397 in strain 630 (Mullany, Pallen, Wilks, Stephen, & Tabaqchali, 1996). This group II intron is found within the gene within orf14, which is believed to be essential for conjugation of the element. Splicing of the group II intron has been demonstrated by PCR with primers reading across the predicted splice site (Roberts, Braun, von Eichel-Streiber, & Mullany, 2001; Roberts, Johanesen, Lyras, Mullany, & Rood, 2001) demonstrating that this group II intron is capable of splicing from the mRNA. However, when the reverse transcriptase encoding domain was disrupted by insertion of a kanamycin resistance gene, the ability of the intron to splice was abolished but Tn5397 was still capable of transfer. One explanation for this is that the intron has inserted very close to the 3' end of the gene and splicing is not required to obtain a functional Orf14. Another group II intron has been found associated with a Tn5397-like element in strain QCD-63Q42 (Brouwer, Warburton, Roberts, Mullany, & Allan, 2011), which inserted within a different gene compared to the strain 630 group II intron. It is not yet known if splicing is required for conjugation of this element. The contribution of group II introns to the overall biology of C. difficile is likely to be low due to the fact that they can perfectly splice out of the pre-mRNA transcript rather than creating a mutation. However, they do offer the possibility of a regulatory step, if they only splice under certain environmental conditions and/or differentially splice under certain conditions then different proteins...