1
|
Abdul Rahman NA, Mohd Desa MN, Masri SN, Taib NM, Sulaiman N, Hazman H, John J. The Molecular Approaches and Challenges of Streptococcus pneumoniae Serotyping for Epidemiological Surveillance in the Vaccine Era. Pol J Microbiol 2023; 72:103-115. [PMID: 37314355 DOI: 10.33073/pjm-2023-023] [Citation(s) in RCA: 3] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/27/2023] [Accepted: 05/09/2023] [Indexed: 06/15/2023] Open
Abstract
Streptococcus pneumoniae (pneumococcus) belongs to the Gram-positive cocci. This bacterium typically colonizes the nasopharyngeal region of healthy individuals. It has a distinct polysaccharide capsule - a virulence factor allowing the bacteria to elude the immune defense mechanisms. Consequently, it might trigger aggressive conditions like septicemia and meningitis in immunocompromised or older individuals. Moreover, children below five years of age are at risk of morbidity and mortality. Studies have found 101 S. pneumoniae capsular serotypes, of which several correlate with clinical and carriage isolates with distinct disease aggressiveness. Introducing pneumococcal conjugate vaccines (PCV) targets the most common disease-associated serotypes. Nevertheless, vaccine selection pressure leads to replacing the formerly dominant vaccine serotypes (VTs) by non-vaccine types (NVTs). Therefore, serotyping must be conducted for epidemiological surveillance and vaccine assessment. Serotyping can be performed using numerous techniques, either by the conventional antisera-based (Quellung and latex agglutination) or molecular-based approaches (sequetyping, multiplex PCR, real-time PCR, and PCR-RFLP). A cost-effective and practical approach must be used to enhance serotyping accuracy to monitor the prevalence of VTs and NVTs. Therefore, dependable pneumococcal serotyping techniques are essential to precisely monitor virulent lineages, NVT emergence, and genetic associations of isolates. This review discusses the principles, associated benefits, and drawbacks of the respective available conventional and molecular approaches, and potentially the whole genome sequencing (WGS) to be directed for future exploration.
Collapse
Affiliation(s)
- Nurul Asyikin Abdul Rahman
- 1Department of Biomedical Sciences, Faculty of Medicine and Health Sciences, Universiti Putra Malaysia, Serdang, Malaysia
- 2School of Biology, Faculty of Applied Sciences, Universiti Teknologi MARA, Kuala Pilah, Malaysia
| | - Mohd Nasir Mohd Desa
- 1Department of Biomedical Sciences, Faculty of Medicine and Health Sciences, Universiti Putra Malaysia, Serdang, Malaysia
| | - Siti Norbaya Masri
- 3Department of Medical Microbiology, Faculty of Medicine and Health Sciences, Universiti Putra Malaysia, Serdang, Malaysia
| | - Niazlin Mohd Taib
- 3Department of Medical Microbiology, Faculty of Medicine and Health Sciences, Universiti Putra Malaysia, Serdang, Malaysia
| | - Nurshahira Sulaiman
- 1Department of Biomedical Sciences, Faculty of Medicine and Health Sciences, Universiti Putra Malaysia, Serdang, Malaysia
| | - Hazmin Hazman
- 1Department of Biomedical Sciences, Faculty of Medicine and Health Sciences, Universiti Putra Malaysia, Serdang, Malaysia
| | - James John
- 4Department of Medical Laboratory Technology, School of Allied Health Science, Sathyabama Institute of Science and Technology, Chennai, India
| |
Collapse
|
2
|
Hill AB, Beitelshees M, Nayerhoda R, Pfeifer BA, Jones CH. Engineering a Next-Generation Glycoconjugate-Like Streptococcus pneumoniae Vaccine. ACS Infect Dis 2018; 4:1553-1563. [PMID: 30180541 PMCID: PMC9930592 DOI: 10.1021/acsinfecdis.8b00100] [Citation(s) in RCA: 15] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/19/2023]
Abstract
We detail the development of a next-generation Streptococcus pneumoniae liposomal encapsulation of polysaccharides (LEPS) vaccine, with design characteristics geared toward best-in-class efficacy. The first generation LEPS vaccine, which contained 20 encapsulated pneumococcal capsular polysaccharides (CPSs) and two surface-displayed virulence-associated proteins (GlpO and PncO), enabling prophylactic potency against 70+ serotypes of Streptococcus pneumoniae (the causative agent of pneumococcal disease), was rationally redesigned for advanced clinical readiness and best-in-class coverage. In doing so, the virulent-specific GlpO protein antigen was removed from the final formulation due to off-target immunogenicity toward bacterial species within the human microbiome, while directed protection was maintained by increasing the dose of PncO from 17 to 68 μg. LEPS formulation parameters also readily facilitated an increase in CPS valency (to a total of 24) and systematic variation in protein-liposome attachment mechanisms in anticipation of clinical translation. An additional safety assessment study demonstrated that LEPS does not exhibit appreciable toxicological effects even when administered at ten times the effective dose. In summary, this new design offers the broadest, safest, and most-complete protection while maintaining desirable glycoconjugate-like features, positioning the LEPS vaccine platform for clinical success and a global health impact.
Collapse
Affiliation(s)
- Andrew B. Hill
- Abcombi Biosciences Inc., 1576 Sweet Home Road, Amherst, New York 14228, United States,Department of Chemical and Biological Engineering, University at Buffalo, The State University of New York, Buffalo, New York 14260, United States
| | - Marie Beitelshees
- Abcombi Biosciences Inc., 1576 Sweet Home Road, Amherst, New York 14228, United States,Department of Chemical and Biological Engineering, University at Buffalo, The State University of New York, Buffalo, New York 14260, United States
| | - Roozbeh Nayerhoda
- Department of Biomedical Engineering, University at Buffalo, The State University of New York, Buffalo, New York 14260, United States
| | - Blaine A. Pfeifer
- Department of Chemical and Biological Engineering, University at Buffalo, The State University of New York, Buffalo, New York 14260, United States,Department of Biomedical Engineering, University at Buffalo, The State University of New York, Buffalo, New York 14260, United States,Corresponding Authors: .,
| | - Charles H. Jones
- Abcombi Biosciences Inc., 1576 Sweet Home Road, Amherst, New York 14228, United States,Corresponding Authors: .,
| |
Collapse
|
3
|
Bittaye M, Cash P, Forbes K. Proteomic variation and diversity in clinical Streptococcus pneumoniae isolates from invasive and non-invasive sites. PLoS One 2017; 12:e0179075. [PMID: 28575057 PMCID: PMC5456405 DOI: 10.1371/journal.pone.0179075] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/02/2017] [Accepted: 05/23/2017] [Indexed: 11/26/2022] Open
Abstract
Streptococcus pneumoniae is responsible for a variety of invasive and non-invasive human infections. There are over 90 serotypes of S. pneumoniae differing in their ability to adapt to the different niches within the host. Two-dimensional gel electrophoresis was used to discriminate clinical S. pneumoniae isolates recovered from either blood cultures (invasive site isolates) or other sites, including sputum, tracheal aspirate, ear, eye and skin swabs (non-invasive site isolates). Global protein expression profiles for five invasive site and six non-invasive site isolates representing five different serotypes (serotypes 4, 6, 9, 14 and 23) were obtained for each isolate and combined into a single data set using Progenesis SameSpots™ software. One-hundred and eighty six protein spots (39% of the protein spots in the dataset) differed significantly (ANOVA, p<0.05) in abundance between the invasive site (101 upregulated protein spots) and non-invasive site (85 upregulated protein spots) isolates. Correlations between the bacterial proteomes and their sites of isolation were determined by Principal Component Analysis (PCA) using the significantly different protein spots. Out of the 186 variable protein spots, 105 exhibited a serotype-associated pattern of variability. The expression of the remaining 81 protein spots was concluded to be uniquely linked to the site of bacterial isolation. Mass spectrometry was used to identify selected protein spots that showed either constant or differential abundance levels. The identified proteins had a diverse range of functions including, capsule biogenesis, DNA repair, protein deglycation, translation, stress response and virulence as well as amino acid, carbohydrate, lipid and nucleotide metabolism. These findings provide insight on the proteins that contribute towards the adaptation of the bacteria to different sites within the host.
Collapse
Affiliation(s)
- Mustapha Bittaye
- School of Medicine, Medical Sciences & Nutrition, University of Aberdeen, Aberdeen, United Kingdom
- * E-mail: ,
| | - Phil Cash
- School of Medicine, Medical Sciences & Nutrition, University of Aberdeen, Aberdeen, United Kingdom
| | - Ken Forbes
- School of Medicine, Medical Sciences & Nutrition, University of Aberdeen, Aberdeen, United Kingdom
| |
Collapse
|
4
|
Salieb-Beugelaar GB, Hunziker PR. Towards nano-diagnostics for bacterial infections. EUROPEAN JOURNAL OF NANOMEDICINE 2015. [DOI: 10.1515/ejnm-2015-0010] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/15/2022]
Abstract
AbstractSensitive, specific and rapid diagnosis of infectious diseases is essential for effective and economic medical care. Focused medical treatment of the patient enabled by pathogen-specific diagnosis may benefit the patient, may reduce cost, and may minimize the risk of drug resistance development. The rapid progress in micro and nanotechnologies contributes to the development of novel diagnostic methods. This critical review assesses emerging nanotechnologies for diagnosis of bacterial infection in developed and developing countries on the background of the current state of the art and includes particular challenges and pitfalls posed by a number of specific pathogens.
Collapse
|
5
|
Wyres KL, Lambertsen LM, Croucher NJ, McGee L, von Gottberg A, Liñares J, Jacobs MR, Kristinsson KG, Beall BW, Klugman KP, Parkhill J, Hakenbeck R, Bentley SD, Brueggemann AB. Pneumococcal capsular switching: a historical perspective. J Infect Dis 2013; 207:439-49. [PMID: 23175765 PMCID: PMC3537446 DOI: 10.1093/infdis/jis703] [Citation(s) in RCA: 134] [Impact Index Per Article: 12.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/18/2012] [Accepted: 09/18/2012] [Indexed: 11/15/2022] Open
Abstract
BACKGROUND Changes in serotype prevalence among pneumococcal populations result from both serotype replacement and serotype (capsular) switching. Temporal changes in serotype distributions are well documented, but the contribution of capsular switching to such changes is unknown. Furthermore, it is unclear to what extent vaccine-induced selective pressures drive capsular switching. METHODS Serotype and multilocus sequence typing data for 426 pneumococci dated from 1937 through 2007 were analyzed. Whole-genome sequence data for a subset of isolates were used to investigate capsular switching events. RESULTS We identified 36 independent capsular switch events, 18 of which were explored in detail with whole-genome sequence data. Recombination fragment lengths were estimated for 11 events and ranged from approximately 19.0 kb to ≥ 58.2 kb. Two events took place no later than 1960, and the imported DNA included the capsular locus and the nearby penicillin-binding protein genes pbp2x and pbp1a. CONCLUSIONS Capsular switching has been a regular occurrence among pneumococcal populations throughout the past 7 decades. Recombination of large DNA fragments (>30 kb), sometimes including the capsular locus and penicillin-binding protein genes, predated both vaccine introduction and widespread antibiotic use. This type of recombination has likely been an intrinsic feature throughout the history of pneumococcal evolution.
Collapse
Affiliation(s)
| | - Lotte M. Lambertsen
- Department of Microbiology Surveillance and Research, Statens Serum Institut, Copenhagen, Denmark
| | - Nicholas J. Croucher
- Pathogen Genomics Team, Wellcome Trust Sanger Institute, Hinxton, United Kingdom
| | - Lesley McGee
- Streptococcus Laboratory, Centers for Disease Control and Prevention, and
| | - Anne von Gottberg
- Centre for Respiratory Diseases and Meningitis, National Institute for Communicable Diseases, Gauteng, South Africa
| | - Josefina Liñares
- Department of Microbiology, Bellvitge Hospital-CIBERes-IDIBELL-UB, Barcelona, Spain
| | - Michael R. Jacobs
- Department of Pathology, Case Western Reserve University, Cleveland, Ohio
| | - Karl G. Kristinsson
- Clinical Microbiology Department, Landspitali University Hospital and University of Iceland, Reykjavik;
| | - Bernard W. Beall
- Streptococcus Laboratory, Centers for Disease Control and Prevention, and
| | - Keith P. Klugman
- Hubert Department of Global Health, Emory University, Atlanta, Georgia
- Centre for Respiratory Diseases and Meningitis, National Institute for Communicable Diseases, Gauteng, South Africa
| | - Julian Parkhill
- Pathogen Genomics Team, Wellcome Trust Sanger Institute, Hinxton, United Kingdom
| | | | - Stephen D. Bentley
- Pathogen Genomics Team, Wellcome Trust Sanger Institute, Hinxton, United Kingdom
| | | |
Collapse
|
6
|
Sequetyping: serotyping Streptococcus pneumoniae by a single PCR sequencing strategy. J Clin Microbiol 2012; 50:2419-27. [PMID: 22553238 DOI: 10.1128/jcm.06384-11] [Citation(s) in RCA: 50] [Impact Index Per Article: 4.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
The introduction of pneumococcal conjugate vaccines necessitates continued monitoring of circulating strains to assess vaccine efficacy and replacement serotypes. Conventional serological methods are costly, labor-intensive, and prone to misidentification, while current DNA-based methods have limited serotype coverage requiring multiple PCR primers. In this study, a computer algorithm was developed to interrogate the capsulation locus (cps) of vaccine serotypes to locate primer pairs in conserved regions that border variable regions and could differentiate between serotypes. In silico analysis of cps from 92 serotypes indicated that a primer pair spanning the regulatory gene cpsB could putatively amplify 84 serotypes and differentiate 46. This primer set was specific to Streptococcus pneumoniae, with no amplification observed for other species, including S. mitis, S. oralis, and S. pseudopneumoniae. One hundred thirty-eight pneumococcal strains covering 48 serotypes were tested. Of 23 vaccine serotypes included in the study, most (19/22, 86%) were identified correctly at least to the serogroup level, including all of the 13-valent conjugate vaccine and other replacement serotypes. Reproducibility was demonstrated by the correct sequetyping of different strains of a serotype. This novel sequence-based method employing a single PCR primer pair is cost-effective and simple. Furthermore, it has the potential to identify new serotypes that may evolve in the future.
Collapse
|
7
|
Albarracín Orio AG, Cortes PR, Tregnaghi M, Piñas GE, Argentinean Network Pneumococcus Study Group, Echenique JR. A new serotype 14 variant of the pneumococcal Spain9V-3 international clone detected in the central region of Argentina. J Med Microbiol 2008; 57:992-999. [PMID: 18628501 DOI: 10.1099/jmm.0.2008/000505-0] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022] Open
Abstract
The penicillin-resistant Spain(9V)-3 clone of Streptococcus pneumoniae is widespread and presents different serotype variants originating from recombination of the capsular genes. In this work, the genetic relatedness of 29 invasive pneumococci isolated from the central region of Argentina (Cordoba, Buenos Aires, Santa Fe and La Pampa provinces) was assessed by multilocus sequence typing (MLST). All of the penicillin-non-susceptible isolates studied (21/29) belonged to a serotype 14 variant of the Spain(9V)-3 clone. This clone was predominant, suggesting that it was responsible for the penicillin resistance spread in this region. Interestingly, this serotype 14 variant (named Cordoba S14V) could be differentiated from the European one by its pbp1a gene, suggesting a different recombinational replacement of the capsular genes. The putative recombination sites were analysed, resulting in the proximal crossover point being clearly localized in the spr0309 gene, with the distal site restricted to the recU gene, confirming a different recombination event. Analysis of the dexB, cpsB, aliA and pbp1a genes from these strains showed a high similarity with the corresponding genes of the Spain(14)-5 clone, suggesting that the capsular genes were provided by this international clone. Analysis of the genetic polymorphisms of the pbp1a (nt 1473-1922) and spr0309 (nt 1-790) genes is proposed as an epidemiological tool to help recognize the Cordoba S14V of the Spain(9V)-3 clone. On the other hand, BOX-repeat-based PCR and MLST analyses of serotype 14 strains revealed a divergent epidemiology of the Cordoba S14V, suggesting a non-recent dissemination in the paediatric population. It is suggested that this molecular epidemiology work will be a reference for monitoring the evolution of S14Vs of Spain(9V)-3, the emergence of new clones and the impact of pneumococcal vaccination programmes in Argentina.
Collapse
Affiliation(s)
- Andrea G Albarracín Orio
- Departamento de Bioquimica Clinica-CIBICI (CONICET), Facultad de Ciencias Quimicas, Universidad Nacional de Cordoba, Cordoba, Argentina
| | - Paulo R Cortes
- Hospital Pediatrico del Niño Jesus, Cordoba, Argentina.,Centro de Desarrollo de Proyectos Avanzados en Pediatria (CEDEPAP), Cordoba, Argentina.,Departamento de Bioquimica Clinica-CIBICI (CONICET), Facultad de Ciencias Quimicas, Universidad Nacional de Cordoba, Cordoba, Argentina
| | - Miguel Tregnaghi
- Centro de Desarrollo de Proyectos Avanzados en Pediatria (CEDEPAP), Cordoba, Argentina
| | - German E Piñas
- Departamento de Bioquimica Clinica-CIBICI (CONICET), Facultad de Ciencias Quimicas, Universidad Nacional de Cordoba, Cordoba, Argentina
| | | | - José R Echenique
- Departamento de Bioquimica Clinica-CIBICI (CONICET), Facultad de Ciencias Quimicas, Universidad Nacional de Cordoba, Cordoba, Argentina
| |
Collapse
|
8
|
Koeck JL, Njanpop-Lafourcade BM, Cade S, Varon E, Sangare L, Valjevac S, Vergnaud G, Pourcel C. Evaluation and selection of tandem repeat loci for Streptococcus pneumoniae MLVA strain typing. BMC Microbiol 2005; 5:66. [PMID: 16287512 PMCID: PMC1315331 DOI: 10.1186/1471-2180-5-66] [Citation(s) in RCA: 35] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/20/2005] [Accepted: 11/16/2005] [Indexed: 11/16/2022] Open
Abstract
Background Precise identification of bacterial pathogens at the strain level is essential for epidemiological purposes. In Streptococcus pneumoniae, the existence of 90 different serotypes makes the typing particularly difficult and requires the use of highly informative tools. Available methods are relatively expensive and cannot be used for large-scale or routine typing of any new isolate. We explore here the potential of MLVA (Multiple Loci VNTR Analysis; VNTR, Variable Number of Tandem Repeats), a method of growing importance in the field of molecular epidemiology, for genotyping of Streptococcus pneumoniae. Results Available genome sequences were searched for polymorphic tandem repeats. The loci identified were typed across a collection of 56 diverse isolates and including a group of serotype 1 isolates from Africa. Eventually a set of 16 VNTRs was proposed for MLVA-typing of S. pneumoniae. These robust markers were sufficient to discriminate 49 genotypes and to aggregate strains on the basis of the serotype and geographical origin, although some exceptions were found. Such exceptions may reflect serotype switching or horizontal transfer of genetic material. Conclusion We describe a simple PCR-based MLVA genotyping scheme for S. pneumoniae which may prove to be a powerful complement to existing tools for epidemiological studies. Using this technique we uncovered a clonal population of strains, responsible for infections in Burkina Faso. We believe that the proposed MLVA typing scheme can become a standard for epidemiological studies of S. pneumoniae.
Collapse
Affiliation(s)
- Jean-Louis Koeck
- Laboratoire de biologie clinique, HIA Robert Picqué, 351, route de Toulouse, 33 140 Villenave d'Ornon, France
| | | | - Sonia Cade
- Laboratoire de biologie clinique, HIA Robert Picqué, 351, route de Toulouse, 33 140 Villenave d'Ornon, France
| | - Emmanuelle Varon
- Centre National de Référence des Pneumocoques, Laboratoire de Microbiologie, Hôpital Européen Georges Pompidou, 20-40 rue Leblanc, 75908 Paris cedex 15, France
| | - Lassana Sangare
- Laboratoire de Virologie-Bactériologie; Centre Hospitalier Universitaire Yalgado Ouédraogo Ouagadougou, Burkina Faso
| | - Samina Valjevac
- Génome, Polymorphisme et Minisatellites (GPMS), Institut de Génétique et Microbiologie, Bat. 400, Université Paris XI, 91405 Orsay cedex, France
- Division of Analytical Microbiology, Centre d'Etude du Bouchet, BP3, 91710 Vert le Petit, France
| | - Gilles Vergnaud
- Génome, Polymorphisme et Minisatellites (GPMS), Institut de Génétique et Microbiologie, Bat. 400, Université Paris XI, 91405 Orsay cedex, France
- Division of Analytical Microbiology, Centre d'Etude du Bouchet, BP3, 91710 Vert le Petit, France
| | - Christine Pourcel
- Génome, Polymorphisme et Minisatellites (GPMS), Institut de Génétique et Microbiologie, Bat. 400, Université Paris XI, 91405 Orsay cedex, France
| |
Collapse
|
9
|
McEllistrem MC, Adams JM, Visweswaran S, Khan SA. Detection of Very High–Level Penicillin-Resistant Variants of the Tennessee23F-4 Clone Via Single and Serial Transformations with Four Serotype 19A International Pneumococcal Clones. Microb Drug Resist 2005; 11:271-8. [PMID: 16201931 DOI: 10.1089/mdr.2005.11.271] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/13/2022] Open
Abstract
In the United States, penicillin-resistant variants of the Tennessee (Tenn) (23 F)-4 clone account for a substantial proportion of the very-high-level penicillin-resistant (MIC 8 microg/ml) infections in the 7-valent pneumococcal protein conjugate vaccine (PCV 7) era. Serotype 19 A strains account for an increasing proportion of penicillin-nonsusceptible Streptococcus pneumoniae infections. Sequential transformations of the Tenn (23 F)-4 clone (penicillin MIC 0.1 microg/ml) were performed with four penicillin-nonsusceptible serotype 19 A international clones (penicillin MIC): S. Africa (19 A)-7 (0.5 microg/ml), Hungary (19 A)-6 (2 microg/ml), Slovakia (19 A)-11 (8 microg/ml), and South Africa (19 A)-13 (8 microg/ml). Fifty-two transformants were characterized by MICs, serogroup-specific PCR, pbp PCR restriction profile and sequence, psp A PCR restriction profile, and erm/mef PCR. A subset was analyzed with multilocus sequence typing (MLST) and pulsed-field gel electrophoresis. Serotype 23 F transformants with penicillin MIC >or= 8 microg/ml were detected through a single transformation with the Hungary (19 A)-6 clone or serial transformations using two to three different clones. Forty-four percent (14/32) of the transformants incorporated >or=1 new MLST allele. Using encapsulated donors, very-high-level penicillin resistant variants of the Tenn (23 F)-4 clone were detected. In addition to detecting stepwise increases in penicillin MIC, a 12-fold increase in penicillin MIC was achieved through a single transformation. This large increase in MIC may explain why this clone is commonly associated with very-high-level resistance in natural populations. Recombination within the MLST housekeeping genes was commonly detected in the transformants that had acquired penicillin resistance.
Collapse
|
10
|
López R, García E. Recent trends on the molecular biology of pneumococcal capsules, lytic enzymes, and bacteriophage. FEMS Microbiol Rev 2005; 28:553-80. [PMID: 15539074 DOI: 10.1016/j.femsre.2004.05.002] [Citation(s) in RCA: 139] [Impact Index Per Article: 7.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/11/2004] [Revised: 05/19/2004] [Accepted: 05/25/2004] [Indexed: 11/23/2022] Open
Abstract
Streptococcus pneumoniae has re-emerged as a major cause of morbidity and mortality throughout the world and its continuous increase in antimicrobial resistance is rapidly becoming a leading cause of concern for public health. This review is focussed on the analysis of recent insights on the study of capsular polysaccharide biosynthesis, and cell wall (murein) hydrolases, two fundamental pneumococcal virulence factors. Besides, we have also re-evaluated the molecular biology of the pneumococcal phage, their possible role in pathogenicity and in the shaping of natural populations of S. pneumoniae. Precise knowledge of the topics reviewed here should facilitate the rationale to move towards the design of alternative ways to combat pneumococcal disease.
Collapse
Affiliation(s)
- Rubens López
- Departamento de Microbiología Molecular, Centro de Investigaciones Biológicas, CSIC, Ramiro de Maeztu, 9, 28040 Madrid, Spain.
| | | |
Collapse
|
11
|
Abstract
Nucleotide sequence-based methods for bacterial typing (multilocus sequence typing; MLST) allow rapid and global comparisons between results from different laboratories. Combining this advantage with the reduced cost of high throughput sequencing, increasing automation and the amenability of sequence data for evolutionary analysis, it seems inevitable that sequence-based typing will eventually predominate over gel-based methods such as pulsed-field gel electrophoresis (PFGE) for most bacterial species. The increasing availability of multiple genome sequences for single pathogenic species, and the recent development of many new MLST schemes, means that a re-examination of the utility of multilocus sequencing, and in particular the choice of gene loci, is now appropriate.
Collapse
Affiliation(s)
- Jessica E Cooper
- Department of Biology and Biochemistry, University of Bath, Claverton Down, Bath, UK
| | | |
Collapse
|