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Zilch TJ, Lee JJ, Bressan GC, McDonough SP, Mohammed HO, Divers TJ, Chang YF. Evaluation of new leptospiral antigens for the diagnosis of equine leptospirosis: An approach using pan-genomic analysis, reverse vaccinology and antigenic selection. Equine Vet J 2020; 53:1025-1035. [PMID: 33135163 DOI: 10.1111/evj.13380] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/27/2020] [Revised: 08/10/2020] [Accepted: 10/23/2020] [Indexed: 11/28/2022]
Abstract
BACKGROUND The current gold standard diagnostic test for leptospirosis is the microscopic agglutination test (MAT), which has many drawbacks; therefore, the development of a better and easier serological test for leptospirosis is needed. OBJECTIVES To apply reverse vaccinology (RV) and antigenic selection on the assortment of leptospiral targets and evaluate their potential for use as reagents for the diagnosis of equine leptospirosis. STUDY DESIGN Cross-sectional study. METHODS The antigenic selection parameters were: proteins with antigenicity score ≥0.5 (VaxiJen), at least one B cell epitope and size between 10 and 275 KDa. New leptospiral proteins were cloned, expressed and serologically screened against equine sera (n = 128) on a single analysis and comparative combinations. Sensitivity (Se) and specificity (Sp), accuracy, positive predictive value (PPV) and negative predictive value (NPV) were calculated. A BLAST with nucleotide and protein sequences was used to identify the serovar or species specificity. MAIN LIMITATIONS This cross-sectional analysis had three main limitations: (a) The equine sera used in these tests were limited to sera submitted to the Animal Health Diagnosis Center and were only tested against seven serovars; (b) MAT results were considered being 'perfect', and the highest titre presented was considered being the infecting serovar, which may not hold true; (c) The strains used to represent the serovars and the limited number of different serovars and species included in the genetic analysis, which leads to the possibility that these proteins might be present in different species or serovars that perhaps would be seroprevalent in another geographic region. CONCLUSIONS The new leptospiral antigens described in this research could increase the sensitivity and specificity of ELISA for detection of Leptospira exposure and the detection of leptospirosis in horses along with support from other clinical signs. Some of these new antigens might be used to improve the detection of infecting serovar.
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Affiliation(s)
- Tiago J Zilch
- Department of Population Medicine and Diagnostic Sciences, College of Veterinary Medicine, Cornell University, Ithaca, New York, USA
| | - Jen-Jie Lee
- Department of Population Medicine and Diagnostic Sciences, College of Veterinary Medicine, Cornell University, Ithaca, New York, USA
| | - Gustavo C Bressan
- Department of Biochemistry and Molecular Biology, Federal University of Viçosa, Viçosa, MG, Brazil
| | - Sean P McDonough
- Department of Biomedical Sciences, College of Veterinary Medicine, Cornell University, Ithaca, New York, USA
| | - Hussni O Mohammed
- Department of Population Medicine and Diagnostic Sciences, College of Veterinary Medicine, Cornell University, Ithaca, New York, USA
| | - Thomas J Divers
- Department of Clinical Sciences, College of Veterinary Medicine, Cornell University, Ithaca, New York, USA
| | - Yung-Fu Chang
- Department of Population Medicine and Diagnostic Sciences, College of Veterinary Medicine, Cornell University, Ithaca, New York, USA
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Briles DE, Paton JC, Mukerji R, Swiatlo E, Crain MJ. Pneumococcal Vaccines. Microbiol Spectr 2019; 7:10.1128/microbiolspec.gpp3-0028-2018. [PMID: 31858954 PMCID: PMC10921951 DOI: 10.1128/microbiolspec.gpp3-0028-2018] [Citation(s) in RCA: 42] [Impact Index Per Article: 8.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/03/2018] [Indexed: 01/14/2023] Open
Abstract
Streptococcus pneumoniae is a Gram-Positive pathogen that is a major causative agent of pneumonia, otitis media, sepsis and meningitis across the world. The World Health Organization estimates that globally over 500,000 children are killed each year by this pathogen. Vaccines offer the best protection against S. pneumoniae infections. The current polysaccharide conjugate vaccines have been very effective in reducing rates of invasive pneumococcal disease caused by vaccine type strains. However, the effectiveness of these vaccines have been somewhat diminished by the increasing numbers of cases of invasive disease caused by non-vaccine type strains, a phenomenon known as serotype replacement. Since, there are currently at least 98 known serotypes of S. pneumoniae, it may become cumbersome and expensive to add many additional serotypes to the current 13-valent vaccine, to circumvent the effect of serotype replacement. Hence, alternative serotype independent strategies, such as vaccination with highly cross-reactive pneumococcal protein antigens, should continue to be investigated to address this problem. This chapter provides a comprehensive discussion of pneumococcal vaccines past and present, protein antigens that are currently under investigation as vaccine candidates, and other alternatives, such as the pneumococcal whole cell vaccine, that may be successful in reducing current rates of disease caused by S. pneumoniae.
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Affiliation(s)
- D E Briles
- Department of Microbiology, University of Alabama at Birmingham, Birmingham, Alabama
| | - J C Paton
- Research Centre for Infectious Diseases, Department of Molecular and Biomedical Science, University of Adelaide, Adelaide, 5005, Australia
| | - R Mukerji
- Department of Microbiology, University of Alabama at Birmingham, Birmingham, Alabama
| | - E Swiatlo
- Section of Infectious Diseases, Southeast Louisiana Veterans Health Care System, New Orleans, LA
| | - M J Crain
- Department of Pediatrics and Microbiology, University of Alabama at Birmingham
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Zeng L, Wang D, Hu N, Zhu Q, Chen K, Dong K, Zhang Y, Yao Y, Guo X, Chang YF, Zhu Y. A Novel Pan-Genome Reverse Vaccinology Approach Employing a Negative-Selection Strategy for Screening Surface-Exposed Antigens against leptospirosis. Front Microbiol 2017; 8:396. [PMID: 28352257 PMCID: PMC5348505 DOI: 10.3389/fmicb.2017.00396] [Citation(s) in RCA: 26] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/25/2016] [Accepted: 02/27/2017] [Indexed: 01/18/2023] Open
Abstract
Reverse vaccinology (RV) has been widely used for screening of surface-exposed proteins (PSEs) of important pathogens, including outer membrane proteins (OMPs), and extracellular proteins (ECPs) as potential vaccine candidates. In this study, we applied a novel RV negative strategy and a pan-genome analysis for screening of PSEs from 17 L. interrogans strains covering 11 predominately epidemic serovars and 17 multilocus typing (MLST) sequence types (STs) worldwide. Our results showed, for instance, out of a total of 633 predicted PSEs in strain 56601, 92.8% were OMPs or ECPs (588/633). Among the 17 strains, 190 core PSEs, 913 dispensable PSEs and 861 unique PSEs were identified. Of the 190 PSEs, 121 were further predicted to be highly antigenic and thus may serve as potential vaccine candidates against leptospirosis. With the exception of LipL45, OmpL1, and LigB, the majority of the 121 PSEs were newly identified antigens. For example, hypothetical proteins BatC, LipL71, and the OmpA family proteins sharing many common features, such as surface-exposed localization, universal conservation, and eliciting strong antibody responses in patients, are regarded as the most promising vaccine antigens. Additionally, a wide array of potential virulence factors among the predicted PSEs including TonB-dependent receptor, sphingomyelinase 2, leucine-rich repeat protein, and 4 neighboring hypothetical proteins were identified as potential antigenicity, and deserve further investigation. Our results can contribute to the prediction of suitable antigens as potential vaccine candidates against leptospirosis and also provide further insights into mechanisms of leptospiral pathogenicity. In addition, our novel negative-screening strategy combined with pan-genome analysis can be a routine RV method applied to numerous other pathogens.
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Affiliation(s)
- LingBing Zeng
- Department of Laboratory Medicine, the First Affiliated Hospital of NanChang UniversityNanchang, China; Department of Medical Microbiology and Immunology, Shanghai Jiao Tong University School of MedicineShanghai, China
| | - Dongliang Wang
- CAS Key Laboratory for Biological Effects of Nanomaterials and Nanosafety, National Center for Nanoscience and Technology Beijing, China
| | - NiYa Hu
- Department of Laboratory Medicine, the First Affiliated Hospital of NanChang University Nanchang, China
| | - Qing Zhu
- Department of Laboratory Medicine, the First Affiliated Hospital of NanChang University Nanchang, China
| | - Kaishen Chen
- Department of Laboratory Medicine, the First Affiliated Hospital of NanChang University Nanchang, China
| | - Ke Dong
- Department of Medical Microbiology and Immunology, Shanghai Jiao Tong University School of Medicine Shanghai, China
| | - Yan Zhang
- Department of Medical Microbiology and Immunology, Shanghai Jiao Tong University School of Medicine Shanghai, China
| | - YuFeng Yao
- Deparment of Molecular Immunology, Institute of Medical Biology, Chinese Academy of Medical Sciences, Peking Union Medical College Kunming, China
| | - XiaoKui Guo
- Department of Medical Microbiology and Immunology, Shanghai Jiao Tong University School of Medicine Shanghai, China
| | - Yung-Fu Chang
- Department of Population Medicine and Diagnostic Sciences, College of Veterinary Medicine, Cornell University Ithaca, NY, USA
| | - YongZhang Zhu
- Department of Medical Microbiology and Immunology, Shanghai Jiao Tong University School of Medicine Shanghai, China
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Ryan AF, Juhn SK, Andalibi A, Bakaletz LO, Ehrlich GD, Jung TTK, Li JD, Lin J, Post CJ. 4A. Molecular Biology. Ann Otol Rhinol Laryngol 2016. [DOI: 10.1177/00034894051140s106] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
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Escolano-Martínez MS, Domenech A, Yuste J, Cercenado MI, Ardanuy C, Liñares J, de la Campa AG, Martin-Galiano AJ. DiiA is a novel dimorphic cell wall protein of Streptococcus pneumoniae involved in invasive disease. J Infect 2016; 73:71-81. [PMID: 27105656 DOI: 10.1016/j.jinf.2016.04.010] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/03/2015] [Revised: 04/06/2016] [Accepted: 04/11/2016] [Indexed: 12/16/2022]
Abstract
OBJECTIVES Many outer multidomain proteins play fundamental virulent roles in an allele-dependent manner. We aimed to investigate the influence of the outer SP1992 protein, here renamed DiiA (Dimorphic invasion-involved A), in pneumococcal disease. METHODS The presence and type of diiA allele was screened by PCR in 560 clinical isolates. Isogenic mutants carrying progressive diiA deletions were constructed and checked in mouse models of infection. DiiA binding to human molecules was carried out by surface plasmon resonance. RESULTS The diiA gene is exclusive of Streptococcus pneumoniae and included in the core genome. DiiA variants contain one or two imperfect repeats (R1 and R2), an unstructured region and a cell-wall anchor domain. Clonal complexes carrying both repeats were associated with invasive disease, while those carrying R2 preferentially caused non-invasive syndromes in patients with underlying risk factors. Mutants lacking both repeats were less efficient in nasopharyngeal colonization and dissemination from lungs. Moreover, the ΔdiiA defective strain suffered a severe impairment in bacterial proliferation in blood. Purified DiiA bound to collagen and lactoferrin with high affinity. CONCLUSIONS DiiA is a distinctive pneumococcal virulence factor contributing to colonization and long-term invasion in this pathogen.
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Affiliation(s)
- María S Escolano-Martínez
- Instituto de Salud Carlos III, Centro Nacional de Microbiología, Carretera a Pozuelo, km 2.2, Majadahonda, 28220 Madrid, Spain
| | - Arnau Domenech
- CIBER de Enfermedades Respiratorias (CIBERES), Spain; Servicio de Microbiología, Hospital Universitari de Bellvitge, Universitat de Barcelona, IDIBELL, Feixa Llarga, sn. L'Hospitalet de Llobregat, 08907 Barcelona, Spain
| | - José Yuste
- Instituto de Salud Carlos III, Centro Nacional de Microbiología, Carretera a Pozuelo, km 2.2, Majadahonda, 28220 Madrid, Spain; CIBER de Enfermedades Respiratorias (CIBERES), Spain
| | - María I Cercenado
- Instituto de Salud Carlos III, Centro Nacional de Microbiología, Carretera a Pozuelo, km 2.2, Majadahonda, 28220 Madrid, Spain
| | - Carmen Ardanuy
- CIBER de Enfermedades Respiratorias (CIBERES), Spain; Servicio de Microbiología, Hospital Universitari de Bellvitge, Universitat de Barcelona, IDIBELL, Feixa Llarga, sn. L'Hospitalet de Llobregat, 08907 Barcelona, Spain
| | - Josefina Liñares
- CIBER de Enfermedades Respiratorias (CIBERES), Spain; Servicio de Microbiología, Hospital Universitari de Bellvitge, Universitat de Barcelona, IDIBELL, Feixa Llarga, sn. L'Hospitalet de Llobregat, 08907 Barcelona, Spain
| | - Adela G de la Campa
- Instituto de Salud Carlos III, Centro Nacional de Microbiología, Carretera a Pozuelo, km 2.2, Majadahonda, 28220 Madrid, Spain; Presidencia, Consejo Superior de Investigaciones Científicas, Madrid, Spain
| | - Antonio J Martin-Galiano
- Instituto de Salud Carlos III, Centro Nacional de Microbiología, Carretera a Pozuelo, km 2.2, Majadahonda, 28220 Madrid, Spain.
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Seib KL, Zhao X, Rappuoli R. Developing vaccines in the era of genomics: a decade of reverse vaccinology. Clin Microbiol Infect 2012; 18 Suppl 5:109-16. [PMID: 22882709 DOI: 10.1111/j.1469-0691.2012.03939.x] [Citation(s) in RCA: 123] [Impact Index Per Article: 10.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/08/2023]
Abstract
Vaccines have a significant impact on public health, and vaccinology in the era of genomics is taking advantage of new technologies to tackle diseases for which vaccine development has so far been unsuccessful. Almost all existing vaccines were developed based on traditional vaccinology methods, which relied on empirical screening of a few candidates at a time, based on known features of the pathogen. However, the ability to sequence a pathogen's genome provides access to its entire antigenic repertoire. As such, genomics has catalysed a shift in vaccine development towards sequence-based 'Reverse Vaccinology' approaches, which use high-throughput in silico screening of the entire genome of a pathogen to identify genes that encode proteins with the attributes of good vaccine targets. Furthermore, the increasing availability of genome sequences has led to the development and application of additional technologies to vaccine discovery, including comparative genomics, transcriptomics, proteomics, immunomics and structural genomics. Vaccine candidates identified from a pathogen's genome or proteome can then be expressed as recombinant proteins and tested in appropriate in vitro or in vivo models to assess immunogenicity and protection. The process of reverse vaccinology has been applied to several pathogens, including serogroup B Neisseria meningitidis, Streptococcus agalactiae, Streptococcus pyogenes, Streptococcus pneumoniae and pathogenic Escherichia coli, and has provided scores of new candidate antigens for preclinical and clinical investigation. As novel genome-based technologies continue to emerge, it is expected that new vaccines for unmet diseases will be within reach.
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Affiliation(s)
- K L Seib
- Novartis Vaccines and Diagnostics, Siena, Italy
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Larentis AL, Argondizzo APC, Esteves GDS, Jessouron E, Galler R, Medeiros MA. Cloning and optimization of induction conditions for mature PsaA (pneumococcal surface adhesin A) expression in Escherichia coli and recombinant protein stability during long-term storage. Protein Expr Purif 2011; 78:38-47. [PMID: 21362478 DOI: 10.1016/j.pep.2011.02.013] [Citation(s) in RCA: 37] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/03/2010] [Revised: 02/22/2011] [Accepted: 02/22/2011] [Indexed: 11/27/2022]
Abstract
The gene corresponding to mature PsaA from Streptococcus pneumoniae serotype 14 was cloned into a plasmid with kanamycin resistance and without a purification tag in Escherichia coli to express high levels of the recombinant protein for large-scale production as a potential vaccine candidate or as a carrier for polysaccharide conjugation at Bio-Manguinhos/Fiocruz. The evaluation of induction conditions (IPTG concentration, temperature and time) in E. coli was accomplished by experimental design techniques to enhance the expression level of mature recombinant PsaA (rPsaA). The optimization of induction process conditions led us to perform the recombinant protein induction at 25°C for 16 h, with 0.1mM IPTG in Terrific Broth medium. At these conditions, the level of mature rPsaA expression obtained in E. coli BL21 (DE3) Star by pET28a induction with IPTG was in the range of 0.8 g/L of culture medium, with a 10-fold lower concentration of inducer than usually employed, which contributes to a less expensive process. Mature rPsaA expressed in E. coli BL21 (DE3) Star accounted for approximately 30-35% of the total protein. rPsaA purification by ion exchange allowed the production of high-purity recombinant protein without fusion tags. The results presented in this work confirm that the purified recombinant protein maintains its stability and integrity for long periods of time in various storage conditions (temperatures of 4 or -70°C using different cryoprotectors) and for at least 3 years at 4 or -70°C in PBS. The conformation of the stored protein was confirmed using circular dichroism. Mature rPsaA antigenicity was proven by anti-rPsaA mouse serum recognition through western blot analysis, and no protein degradation was detected after long periods of storage.
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Affiliation(s)
- Ariane Leites Larentis
- Fundação Oswaldo Cruz (Fiocruz), Bio-Manguinhos/VDTEC (Vice-Diretoria de Desenvolvimento Tecnológico), Laboratório de Tecnologia Recombinante (LATER), Av. Brasil 4365, 21.040-360, Rio de Janeiro - RJ, Brazil.
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Virulence attenuation of Streptococcus pneumoniae clpP mutant by sensitivity to oxidative stress in macrophages via an NO-mediated pathway. J Microbiol 2010; 48:229-35. [PMID: 20437156 DOI: 10.1007/s12275-010-9300-0] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/26/2009] [Accepted: 10/27/2009] [Indexed: 12/22/2022]
Abstract
ClpP protease is essential for virulence and survival under stress conditions in several pathogenic bacteria. The clpP mutation in a murine infection model has demonstrated both attenuation of virulence and a sensitivity to hydrogen peroxide. However, the underlying mechanisms for these changes have not been resolved. Because macrophages play a major role in immune response and activated macrophages can kill microbes via oxygen-dependant mechanisms, we investigated the effect of the clpP mutation on its sensitivity to macrophage-mediated oxygen-dependant mechanisms. The clpP mutant derived from D39 (serotype 2) exhibited a higher sensitivity to oxidative stresses such as reactive oxygen intermediates, reactive nitrogen intermediates, and H(2)O(2), but no sensitivity to osmotic stress (NaCl) and pH. Moreover, viability of the clpP mutant was significantly increased in murine macrophage cells by treatment with S-methylisothiourea sulfate, which inhibits inducible nitric oxide synthase (iNOS) activity and subsequently elicits lower level secretions of nitric oxide (NO). However, viability of wild type was unchanged. Taken together, these results indicate that ClpP is involved in the resistance to oxidative stresses after entrapment by macrophages and subsequently contributes to virulence via NO mediated pathway.
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Abstract
We characterized two sucrose-metabolizing systems -sus and scr- and describe their roles in the physiology and virulence of Streptococcus pneumoniae in murine models of carriage and pneumonia. The sus and scr systems are regulated by LacI family repressors SusR and ScrR respectively. SusR regulates an adjacent ABC transporter (susT1/susT2/susX) and sucrose-6-phosphate (S-6-P) hydrolase (susH). ScrR controls an adjacent PTS transporter (scrT), fructokinase (scrK) and second S-6-P hydrolase (scrH). sus and scr play niche-specific roles in virulence. The susH and sus locus mutants are attenuated in the lung, but dispensable in nasopharyngeal carriage. Conversely, the scrH and scr locus mutants, while dispensable in the lung, are attenuated for nasopharyngeal colonization. The scrH/susH double mutant is more attenuated than scrH in the nasopharynx, indicating SusH can substitute in this niche. Both systems are sucrose-inducible, with ScrH being the major in vitro hydrolase. The scrH/susH mutant does not grow on sucrose indicating that sus and scr are the only sucrose-metabolizing systems in S. pneumoniae. We propose a model describing hierarchical regulation of the scr and sus systems by the putative inducer, S-6-P. The transport and metabolism of sucrose or a related disaccharide thus contributes to S. pneumoniae colonization and disease.
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Affiliation(s)
- Ramkumar Iyer
- Howard Hughes Medical Institute, 136 Harrison Avenue, Tufts University, Boston, MA 02110, USA
| | - Andrew Camilli
- Department of Molecular Biology and Microbiology, 136 Harrison Avenue, Tufts University, Boston, MA 02110, USA
- For correspondence. ; Tel. (+1) 617 636 6933; Fax (+1) 617 636 2175
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Desa MN, Sekaran SD, Vadivelu J, Parasakthi N. Distribution of CBP genes in Streptococcus pneumoniae isolates in relation to vaccine types, penicillin susceptibility and clinical site. Epidemiol Infect 2007; 136:940-2. [PMID: 17678563 PMCID: PMC2870887 DOI: 10.1017/s0950268807009363] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/07/2022] Open
Abstract
Choline-binding proteins (CBP) have been associated with the pathogenesis of Streptococcus pneumoniae. We screened, using PCR, for the presence of genes (cbpA, D, E, G) encoding these proteins in 34 isolates of pneumococci of known serotypes and penicillin susceptibility from invasive and non-invasive disease. All isolates harboured cbpD and cbpE whereas cbpA and cbpG were found in 47% and 59% respectively; the latter were more frequent in vaccine-associated types and together accounted for 77% of these isolates. No association was observed with penicillin susceptibility but 85% of non-invasive isolates were positive for these genes.
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Affiliation(s)
- M N Desa
- Department of Biomedical Sciences, Faculty of Medicine & Health Sciences, Universiti Putra Malaysia, Serdang, Selangor, Malaysia.
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Iyer R, Baliga NS, Camilli A. Catabolite control protein A (CcpA) contributes to virulence and regulation of sugar metabolism in Streptococcus pneumoniae. J Bacteriol 2006; 187:8340-9. [PMID: 16321938 PMCID: PMC1317011 DOI: 10.1128/jb.187.24.8340-8349.2005] [Citation(s) in RCA: 151] [Impact Index Per Article: 8.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
We characterized the role of catabolite control protein A (ccpA) in the physiology and virulence of Streptococcus pneumoniae. S. pneumoniae has a large percentage of its genome devoted to sugar uptake and metabolism, and therefore, regulation of these processes is likely to be crucial for fitness in the nasopharynx and may play a role during invasive disease. In many bacteria, carbon catabolite repression (CCR) is central to such regulation, influencing hierarchical sugar utilization and growth rates. CcpA is the major transcriptional regulator in CCR in several gram-positive bacteria. We show that CcpA functions in CCR of lactose-inducible beta-galactosidase activity in S. pneumoniae. CCR of maltose-inducible alpha-glucosidase, raffinose-inducible alpha-galactosidase, and cellobiose-inducible beta-glucosidase is unaffected in the ccpA strain, suggesting that other regulators, possibly redundant with CcpA, control these systems. The ccpA strain is severely attenuated for nasopharyngeal colonization and lung infection in the mouse, establishing its role in fitness on these mucosal surfaces. Comparison of the cell wall fraction of the ccpA and wild-type strains shows that CcpA regulates many proteins in this compartment that are involved in central and intermediary metabolism, a subset of which are required for survival and multiplication in vivo. Both in vitro and in vivo defects were complemented by providing ccpA in trans. Our results demonstrate that CcpA, though not a global regulator of CCR in S. pneumoniae, is required for colonization of the nasopharynx and survival and multiplication in the lung.
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Affiliation(s)
- Ramkumar Iyer
- Department of Molecular Biology and Microbiology, Tufts University, 136 Harrison Avenue, Boston, MA 02111, USA
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Hava DL, Camilli A. Large-scale identification of serotype 4 Streptococcus pneumoniae virulence factors. Mol Microbiol 2002. [DOI: 10.1046/j.1365-2958.2002.03106.x] [Citation(s) in RCA: 65] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022]
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Hava DL, Camilli A. Large-scale identification of serotype 4 Streptococcus pneumoniae virulence factors. Mol Microbiol 2002. [DOI: 10.1046/j.1365-2958.2002.t01-1-03106.x] [Citation(s) in RCA: 25] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022]
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