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Alnakip MEA, Rhouma NR, Abd-Elfatah EN, Quintela-Baluja M, Böhme K, Fernández-No I, Bayoumi MA, Abdelhafez MM, Taboada-Rodríguez A, Calo-Mata P, Barros-Velázquez J. Discrimination of major and minor streptococci incriminated in bovine mastitis by MALDI-TOF MS fingerprinting and 16S rRNA gene sequencing. Res Vet Sci 2020; 132:426-438. [PMID: 32777539 DOI: 10.1016/j.rvsc.2020.07.027] [Citation(s) in RCA: 15] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/18/2020] [Revised: 06/13/2020] [Accepted: 07/30/2020] [Indexed: 02/05/2023]
Abstract
The current work investigated the discriminatory potential of MALDI-TOF MS fingerprinting towards most-relevant major (Streptococcus agalactiae, S. dysgalactiae, S. uberis) and minor (S. canis, S. parauberis, S. salivarius, S. equinus and S. gallolyticus) streptococci involved in bovine mastitis (BM), in comparison to 16S rRNA gene sequencing (GS)-based identification. The MALDI-TOF MS-generated spectral fingerprints were recruited for eliciting a detailed proteomic map that demonstrated clear variability for inter- and intra-species-specific biomarkers. Besides, a phyloproteomic dendrogram was evolved and comparatively analyzed against the phylogenetic one obtained from 16S rRNA GS in order to assess the differentiation of streptococci of bovine origin based on variability of protein fingerprints versus the variation of 16S rRNA gene homology. Results showed that the discrimination of BM-implicated streptococci can be obtained by both approaches; however MALDI-TOF MS was superior, achieving more variability at both intra- and sub-species levels. MALDI-TOF MS spectral analytics revealed that Streptococcus spp. exhibited three genus-specific biomarkers (peaks with m/z values at 2112, 4452 and 5955) and all streptococci exhibited spectral variability at both species and subspecies levels. Remarkably, MALDI-TOF MS fingerprinting was found to be at least as robust as 16S rRNA GS-based identification, allowing much cheaper and faster analysis, and additionally exhibiting high reliability for characterization of BM-implicated streptococci, thus proving to be a powerful tool that can be used independently within dairy diagnostics.
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Affiliation(s)
- Mohamed E A Alnakip
- Department of Analytical Chemistry, Nutrition and Food Science, School of Veterinary Sciences/College of Biotechnology, University of Santiago de Compostela, Rúa Carballo Calero s/n, Campus Lugo, E-27002 Lugo, Spain; Department of Food Control, Faculty of Veterinary Medicine, Zagazig University, 44519, Egypt
| | - Nasreddin R Rhouma
- Department of Biology, Faculty of Science, Misurata University, Libya; Department of Food science and Technology, Faculty of Agriculture, Misurata University, Libya
| | - Eman N Abd-Elfatah
- Department of Food Control, Faculty of Veterinary Medicine, Zagazig University, 44519, Egypt
| | - Marcos Quintela-Baluja
- Department of Analytical Chemistry, Nutrition and Food Science, School of Veterinary Sciences/College of Biotechnology, University of Santiago de Compostela, Rúa Carballo Calero s/n, Campus Lugo, E-27002 Lugo, Spain
| | - Karola Böhme
- Department of Analytical Chemistry, Nutrition and Food Science, School of Veterinary Sciences/College of Biotechnology, University of Santiago de Compostela, Rúa Carballo Calero s/n, Campus Lugo, E-27002 Lugo, Spain
| | - Inmaculada Fernández-No
- Department of Analytical Chemistry, Nutrition and Food Science, School of Veterinary Sciences/College of Biotechnology, University of Santiago de Compostela, Rúa Carballo Calero s/n, Campus Lugo, E-27002 Lugo, Spain
| | - Mohmaed A Bayoumi
- Department of Food Control, Faculty of Veterinary Medicine, Zagazig University, 44519, Egypt
| | - Mostafa M Abdelhafez
- Department of Food science and Technology, Faculty of Agriculture, Misurata University, Libya
| | - Amaury Taboada-Rodríguez
- Food Biotechnology Group, Department of Nutrition and Food Science, Faculty of Veterinary Sciences, Murcia university, Campus Espinardo, 30100 Murcia, Spain
| | - Pillar Calo-Mata
- Department of Analytical Chemistry, Nutrition and Food Science, School of Veterinary Sciences/College of Biotechnology, University of Santiago de Compostela, Rúa Carballo Calero s/n, Campus Lugo, E-27002 Lugo, Spain
| | - J Barros-Velázquez
- Department of Analytical Chemistry, Nutrition and Food Science, School of Veterinary Sciences/College of Biotechnology, University of Santiago de Compostela, Rúa Carballo Calero s/n, Campus Lugo, E-27002 Lugo, Spain.
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Bacteria Modify Candida albicans Hypha Formation, Microcolony Properties, and Survival within Macrophages. mSphere 2020; 5:5/4/e00689-20. [PMID: 32759336 PMCID: PMC7407070 DOI: 10.1128/msphere.00689-20] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
Candida albicans is the predominant fungus colonizing the oral cavity that can have both synergistic and antagonistic interactions with other bacteria. Interkingdom polymicrobial associations modify fungal pathogenicity and are believed to increase microbial resistance to innate immunity. However, it is not known how these interactions alter fungal survival during phagocytic killing. We demonstrated that secreted molecules of S. gordonii and P. aeruginosa alter C. albicans survival within the phagosome of macrophages and alter fungal pathogenic phenotypes, including filamentation and microcolony formation. Moreover, we provide evidence for a dual interaction between S. gordonii and C. albicans such that S. gordonii signaling peptides can promote C. albicans commensalism by decreasing microcolony attachment while increasing invasion in epithelial cells. Our results identify bacterial diffusible factors as an attractive target to modify virulence of C. albicans in polymicrobial infections. Phagocytic cells are crucial components of the innate immune system preventing Candida albicans mucosal infections. Streptococcus gordonii and Pseudomonas aeruginosa often colonize mucosal sites, along with C. albicans, and yet interkingdom interactions that might alter the survival and escape of fungi from macrophages are not understood. Murine macrophages were coinfected with S. gordonii or P. aeruginosa, along with C. albicans to evaluate changes in fungal survival. S. gordonii increased C. albicans survival and filamentation within macrophage phagosomes, while P. aeruginosa reduced fungal survival and filamentation. Coinfection with S. gordonii resulted in greater escape of C. albicans from macrophages and increased size of fungal microcolonies formed on macrophage monolayers, while coinfection with P. aeruginosa reduced macrophage escape and produced smaller microcolonies. Microcolonies formed in the presence of P. aeruginosa cells outside macrophages also had significantly reduced size that was not found with P. aeruginosa phenazine deletion mutants. S. gordonii cells, as well as S. gordonii heat-fixed culture supernatants, increased C. albicans microcolony biomass but also resulted in microcolony detachment. A heat-resistant, trypsin-sensitive pheromone processed by S. gordonii Eep was needed for these effects. The majority of fungal microcolonies formed on human epithelial monolayers with S. gordonii supernatants developed as large floating structures with no detectable invasion of epithelium, along with reduced gene expression of C. albicansHYR1, EAP1, and HWP2 adhesins. However, a subset of C. albicans microcolonies was smaller and had greater epithelial invasiveness compared to microcolonies grown without S. gordonii. Thus, bacteria can alter the killing and escape of C. albicans from macrophages and contribute to changes in C. albicans pathogenicity. IMPORTANCECandida albicans is the predominant fungus colonizing the oral cavity that can have both synergistic and antagonistic interactions with other bacteria. Interkingdom polymicrobial associations modify fungal pathogenicity and are believed to increase microbial resistance to innate immunity. However, it is not known how these interactions alter fungal survival during phagocytic killing. We demonstrated that secreted molecules of S. gordonii and P. aeruginosa alter C. albicans survival within the phagosome of macrophages and alter fungal pathogenic phenotypes, including filamentation and microcolony formation. Moreover, we provide evidence for a dual interaction between S. gordonii and C. albicans such that S. gordonii signaling peptides can promote C. albicans commensalism by decreasing microcolony attachment while increasing invasion in epithelial cells. Our results identify bacterial diffusible factors as an attractive target to modify virulence of C. albicans in polymicrobial infections.
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An Overview on Streptococcus bovis/Streptococcus equinus Complex Isolates: Identification to the Species/Subspecies Level and Antibiotic Resistance. Int J Mol Sci 2019; 20:ijms20030480. [PMID: 30678042 PMCID: PMC6386949 DOI: 10.3390/ijms20030480] [Citation(s) in RCA: 32] [Impact Index Per Article: 6.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/20/2018] [Revised: 01/14/2019] [Accepted: 01/20/2019] [Indexed: 01/09/2023] Open
Abstract
Streptococcus bovis/Streptococcus equinus complex (SBSEC), a non-enterococcal group D Streptococcus spp. complex, has been described as commensal bacteria in humans and animals, with a fecal carriage rate in humans varying from 5% to over 60%. Among streptococci, SBSEC isolates represent the most antibiotic-resistant species—with variable resistance rates reported for clindamycin, erythromycin, tetracycline, and levofloxacin—and might act as a reservoir of multiple acquired genes. Moreover, reduced susceptibility to penicillin and vancomycin associated with mobile genetic elements have also been detected, although rarely. Since the association of SBSEC bacteremia and colon lesions, infective endocarditis and hepatobiliary diseases has been established, particularly in elderly individuals, an accurate identification of SBSEC isolates to the species and subspecies level, as well as the evaluation of antibiotic resistance, are needed. In this paper, we reviewed the major methods used to identify SBSEC isolates and the antimicrobial resistance rates reported in the scientific literature among SBSEC species.
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Millo G, Juntavee A, Ratanathongkam A, Nualkaew N, Peerapattana J, Chatchiwiwattana S. Antibacterial Inhibitory Effects of Punica Granatum Gel on Cariogenic Bacteria: An in vitro Study. Int J Clin Pediatr Dent 2017; 10:152-157. [PMID: 28890615 PMCID: PMC5571384 DOI: 10.5005/jp-journals-10005-1426] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/26/2016] [Accepted: 09/29/2016] [Indexed: 11/23/2022] Open
Abstract
AIM This study evaluated the in vitro antibacterial effects of the formulated Punica granatum (PG) gel against Streptococcus mutans, Streptococcus sanguinis, and Lactobacillus casei. MATERIALS AND METHODS The PG extract was dissolved in water at 500 mg/mL. High performance liquid chromatography (HPLC) was used for identification and quantification of chemical marker punicalagin. Minimum bactericidal concentration (MBC) and time-kill assay (TKA) were investigated. Antibacterial activities of the formulated PG gel, 2% chlorhexidine (CHX) gel and blank gel were tested by measuring the zones of inhibition through agar well diffusion method. RESULTS The HPLC results showed presence of punicalagin at 2023.58 ± 25.29 pg/mL in the aqueous PG extract and at 0.234% (w/w) in the formulated PG gel. The MBC for S. mutans, S. Sanguinis, and L. casei were 250, 125, and 500 mg/mL respectively. The TKA of 500 mg/mL aqueous PG extract showed total inhibition of S. mutans, S. Sanguinis, and L. casei at 6, 1, and 24 hours contact time respectively. Agar well diffusion revealed that for S. mutans, CHX gel > PG gel > blank gel; for S. sanguinis, CHX gel = PG gel > blank gel; for L. casei, CHX gel > PG gel = blank gel. Comparison of the PG gel potency showed that S. sanguinis = S. mutans > L. casei. CONCLUSION The PG gel equivalent to 0.234% punicalagin (w/w) inhibited S. mutans and S. sanguinis but not L. casei within 24 hours incubation period and has the potential to be used for caries prevention. HOW TO CITE THIS ARTICLE Millo G, Juntavee A, Ratanathongkam A, Nualkaew N, Peerapattana J, Chatchiwiwattana S. Antibacterial Inhibitory Effects of Punica Granatum Gel on Cariogenic Bacteria: An in vitro Study. Int J Clin Pediatr Dent 2017;10(2):152-157.
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Affiliation(s)
- Grazielle Millo
- Graduate Student, Department of Pediatric Dentistry, Faculty of Dentistry, Khon Kaen University, Khon Kaen, Thailand
| | - Apa Juntavee
- Associate Professor, Department of Pediatric Dentistry, Faculty of Dentistry, Khon Kaen University, Khon Kaen, Thailand
| | - Ariya Ratanathongkam
- Associate Professor, Department of Oral Biology, Faculty of Dentistry, Khon Kaen University, Khon Kaen, Thailand
| | - Natsajee Nualkaew
- Assistant Professor, Department of Pharmacognosy and Toxicity, Faculty of Pharmaceutical Sciences, Khon Kaen University, Khon Kaen Thailand
| | - Jomjai Peerapattana
- Associate Professor, Department of Pharmaceutical Technology, Faculty of Pharmaceutical Sciences, Khon Kaen University, Khon Kaen Thailand
| | - Supaporn Chatchiwiwattana
- Associate Professor, Department of Oral Biology, Faculty of Dentistry, Khon Kaen University, Khon Kaen, Thailand
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Matos AO, Ricomini-Filho AP, Beline T, Ogawa ES, Costa-Oliveira BE, de Almeida AB, Nociti Junior FH, Rangel EC, da Cruz NC, Sukotjo C, Mathew MT, Barão VA. Three-species biofilm model onto plasma-treated titanium implant surface. Colloids Surf B Biointerfaces 2017; 152:354-366. [DOI: 10.1016/j.colsurfb.2017.01.035] [Citation(s) in RCA: 29] [Impact Index Per Article: 4.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/22/2016] [Revised: 12/16/2016] [Accepted: 01/18/2017] [Indexed: 12/11/2022]
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Dynamics of the Streptococcus gordonii Transcriptome in Response to Medium, Salivary α-Amylase, and Starch. Appl Environ Microbiol 2015; 81:5363-74. [PMID: 26025889 DOI: 10.1128/aem.01221-15] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/14/2015] [Accepted: 05/22/2015] [Indexed: 01/14/2023] Open
Abstract
Streptococcus gordonii, a primary colonizer of the tooth surface, interacts with salivary α-amylase via amylase-binding protein A (AbpA). This enzyme hydrolyzes starch to glucose, maltose, and maltodextrins that can be utilized by various oral bacteria for nutrition. Microarray studies demonstrated that AbpA modulates gene expression in response to amylase, suggesting that the amylase-streptococcal interaction may function in ways other than nutrition. The goal of this study was to explore the role of AbpA in gene regulation through comparative transcriptional profiling of wild-type KS1 and AbpA(-) mutant KS1ΩabpA under various environmental conditions. A portion of the total RNA isolated from mid-log-phase cells grown in 5% CO2 in (i) complex medium with or without amylase, (ii) defined medium (DM) containing 0.8% glucose with/without amylase, and (iii) DM containing 0.2% glucose and amylase with or without starch was reverse transcribed to cDNA and the rest used for RNA sequencing. Changes in the expression of selected genes were validated by quantitative reverse transcription-PCR. Maltodextrin-associated genes, fatty acid synthesis genes and competence genes were differentially expressed in a medium-dependent manner. Genes in another cluster containing a putative histidine kinase/response regulator, peptide methionine sulfoxide reductase, thioredoxin protein, lipoprotein, and cytochrome c-type protein were downregulated in KS1ΩabpA under all of the environmental conditions tested. Thus, AbpA appears to modulate genes associated with maltodextrin utilization/transport and fatty acid synthesis. Importantly, in all growth conditions AbpA was associated with increased expression of a potential two-component signaling system associated with genes involved in reducing oxidative stress, suggesting a role in signal transduction and stress tolerance.
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Isaksson J, Rasmussen M, Nilson B, Stadler LS, Kurland S, Olaison L, Ek E, Herrmann B. Comparison of species identification of endocarditis associated viridans streptococci using rnpB genotyping and 2 MALDI-TOF systems. Diagn Microbiol Infect Dis 2014; 81:240-5. [PMID: 25616316 DOI: 10.1016/j.diagmicrobio.2014.12.007] [Citation(s) in RCA: 41] [Impact Index Per Article: 4.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/25/2014] [Revised: 10/28/2014] [Accepted: 12/20/2014] [Indexed: 11/17/2022]
Abstract
Streptococcus spp. are important causes of infective endocarditis but challenging in species identification. This study compared identification based on sequence determination of the rnpB gene with 2 systems of matrix-assisted laser desorption ionization-time of flight mass spectrometry, MALDI Biotyper (Bruker) and VITEK MS IVD (bioMérieux). Blood culture isolates of viridans streptococci from 63 patients with infective endocarditis were tested. The 3 methods showed full agreement for all 36 isolates identified in the Anginosus, Bovis, and Mutans groups or identified as Streptococcus cristatus, Streptococcus gordonii, or Streptococcus sanguinis. None of the methods could reliably identify the 23 isolates to the species level when designated as Streptococcus mitis, Streptococcus oralis, or Streptococcus tigurinus. In 7 isolates classified to the Mitis group, the rnpB sequences deviated strikingly from all reference sequences, and additional analysis of sodA and groEL genes indicated the occurrence of yet unidentified Streptococcus spp.
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Affiliation(s)
- Jenny Isaksson
- Section of Clinical Bacteriology, Department of Medical Sciences, Uppsala University, SE-751 85 Uppsala, Sweden
| | - Magnus Rasmussen
- Division for Infection Medicine, Department of Clinical Sciences, Lund University, BMC B14, SE-22184 Lund, Sweden
| | - Bo Nilson
- Clinical Microbiology, Labmedicin, Region Skåne, SE-221 85 Lund, Sweden; Department of Laboratory Medicine Lund, Section of Medical Microbiology, Lund University, SE-22362 Lund, Sweden
| | - Liselott Svensson Stadler
- Department of Infectious Diseases, Sahlgrenska Academy, University of Gothenburg, SE-413 46 Gothenburg, Sweden
| | - Siri Kurland
- Section of Infectious Diseases, Department of Medical Sciences, Uppsala University, SE-751 85 Uppsala, Sweden
| | - Lars Olaison
- Department of Infectious Diseases, Institute of Biomedicine, University of Gothenburg, SE-416 85 Gothenburg, Sweden
| | - Elisabeth Ek
- Section of Infectious Diseases, Department of Medical Sciences, University of Gothenburg, SE-413 46 Gothenburg, Sweden
| | - Björn Herrmann
- Section of Clinical Bacteriology, Department of Medical Sciences, Uppsala University, SE-751 85 Uppsala, Sweden.
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Ricker A, Vickerman M, Dongari-Bagtzoglou A. Streptococcus gordonii glucosyltransferase promotes biofilm interactions with Candida albicans. J Oral Microbiol 2014; 6:23419. [PMID: 24490004 PMCID: PMC3907680 DOI: 10.3402/jom.v6.23419] [Citation(s) in RCA: 47] [Impact Index Per Article: 4.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/22/2013] [Revised: 01/03/2014] [Accepted: 01/06/2014] [Indexed: 12/02/2022] Open
Abstract
Background Candida albicans co-aggregates with Streptococcus gordonii to form biofilms and their interactions in mucosal biofilms may lead to pathogenic synergy. Although the functions of glucosyltransferases (Gtf) of Mutans streptococci have been well characterized, the biological roles of these enzymes in commensal oral streptococci, such as S. gordonii, in oral biofilm communities are less clear. Objective The objective of this work was to explore the role of GtfG, the single Gtf enzyme of S. gordonii, in biofilm interactions with C. albicans. Design Biofilms were grown under salivary flow in flow cells in vitro, or under static conditions in 96 well plates. A panel of isogenic S. gordonii CH1 gtfG mutants and complemented strains were co-inoculated with C. albicans strain SC5314 to form mixed biofilms. Biofilm accretion and binding interactions between the two organisms were tested. Biofilms were quantified using confocal microscopy or the crystal violet assay. Results The presence of GtfG enhanced dual biofilm accretion, and sucrose supplementation further augmented dual biofilm formation, pointing to a role of newly synthesized glucans. GtfG also promoted binding to C. albicans preformed biofilms. Soluble α-1,6-glucans played a role in these interactions since: 1) a strain producing only soluble glucans (CH107) formed robust dual biofilms under conditions of salivary flow; and 2) the dual biofilm was susceptible to enzymatic breakdown by dextranase which specifically degrades soluble α-1,6-glucans. Conclusion Our work identified a novel molecular mechanism for C. albicans and S. gordonii biofilm interactions, mediated by GtfG. This protein promotes early biofilm binding of S. gordonii to C. albicans which leads to increased accretion of streptococcal cells in mixed biofilms. We also showed that soluble glucans, with α-1,6-linkages, promoted inter-generic adhesive interactions.
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Affiliation(s)
- Austin Ricker
- School of Dental Medicine, University of Connecticut Health Center, Farmington, CT, USA
| | - Margaret Vickerman
- School of Dental Medicine, State University of New York at Buffalo, Buffalo, NY, USA
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Abstract
Acute apical abscess is the most common form of dental abscess and is caused by infection of the root canal of the tooth. It is usually localized intraorally, but in some cases the apical abscess may spread and result in severe complications or even mortality. The reasons why dental root canal infections can become symptomatic and evolve to severe spreading and sometimes life-threatening abscesses remain elusive. Studies using culture and advanced molecular microbiology methods for microbial identification in apical abscesses have demonstrated a multispecies community conspicuously dominated by anaerobic bacteria. Species/phylotypes commonly found in these infections belong to the genera Fusobacterium, Parvimonas, Prevotella, Porphyromonas, Dialister, Streptococcus, and Treponema. Advances in DNA sequencing technologies and computational biology have substantially enhanced the knowledge of the microbiota associated with acute apical abscesses and shed some light on the etiopathogeny of this disease. Species richness and abundance and the resulting network of interactions among community members may affect the collective pathogenicity and contribute to the development of acute infections. Disease modifiers, including transient or permanent host-related factors, may also influence the development and severity of acute abscesses. This review focuses on the current evidence about the etiology and treatment of acute apical abscesses and how the process is influenced by host-related factors and proposes future directions in research, diagnosis, and therapeutic approaches to deal with this disease.
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Lal D, Verma M, Lal R. Exploring internal features of 16S rRNA gene for identification of clinically relevant species of the genus Streptococcus. Ann Clin Microbiol Antimicrob 2011; 10:28. [PMID: 21702978 PMCID: PMC3151204 DOI: 10.1186/1476-0711-10-28] [Citation(s) in RCA: 34] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/30/2011] [Accepted: 06/25/2011] [Indexed: 12/04/2022] Open
Abstract
BACKGROUND Streptococcus is an economically important genus as a number of species belonging to this genus are human and animal pathogens. The genus has been divided into different groups based on 16S rRNA gene sequence similarity. The variability observed among the members of these groups is low and it is difficult to distinguish them. The present study was taken up to explore 16S rRNA gene sequence to develop methods that can be used for preliminary identification and can supplement the existing methods for identification of clinically-relevant isolates of the genus Streptococcus. METHODS 16S rRNA gene sequences belonging to the isolates of S. dysgalactiae, S. equi, S. pyogenes, S. agalactiae, S. bovis, S. gallolyticus, S. mutans, S. sobrinus, S. mitis, S. pneumoniae, S. thermophilus and S. anginosus were analyzed with the purpose to define genetic variability within each species to generate a phylogenetic framework, to identify species-specific signatures and in-silico restriction enzyme analysis. RESULTS The framework based analysis was used to segregate Streptococcus spp. previously identified upto genus level. This segregation was validated using species-specific signatures and in-silico restriction enzyme analysis. 43 uncharacterized Streptococcus spp. could be identified using this approach. CONCLUSIONS The markers generated exploring 16S rRNA gene sequences provided useful tool that can be further used for identification of different species of the genus Streptococcus.
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Affiliation(s)
- Devi Lal
- Molecular Biology Laboratory, Department of Zoology, University of Delhi, Delhi-110007, India
| | - Mansi Verma
- Molecular Biology Laboratory, Department of Zoology, University of Delhi, Delhi-110007, India
| | - Rup Lal
- Molecular Biology Laboratory, Department of Zoology, University of Delhi, Delhi-110007, India
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Sonbol H, Spratt D, Roberts GJ, Lucas VS. Prevalence, intensity and identity of bacteraemia following conservative dental procedures in children. ACTA ACUST UNITED AC 2009; 24:177-82. [DOI: 10.1111/j.1399-302x.2008.00492.x] [Citation(s) in RCA: 27] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/27/2022]
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Innings A, Krabbe M, Ullberg M, Herrmann B. Identification of 43 Streptococcus species by pyrosequencing analysis of the rnpB gene. J Clin Microbiol 2006; 43:5983-91. [PMID: 16333086 PMCID: PMC1317172 DOI: 10.1128/jcm.43.12.5983-5991.2005] [Citation(s) in RCA: 57] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
Pyrosequencing technology was evaluated for identification of species within the Streptococcus genus. Two variable regions in the rnpB gene, which encodes the RNA subunit of endonuclease P, were sequenced in two reactions. Of 43 species, all could be identified to the species level except strains of the species pairs Streptococcus anginosus/S. constellatus and S. infantis/S. peroris. A total of 113 blood culture isolates were identified by pyrosequencing analysis of partial rnpB sequences. All but eight isolates could be unambiguously assigned to a specific species when the first 30 nucleotides of the two regions were compared to an rnpB database comprising 107 streptococcal strains. Principal coordinate analysis of sequence variation of strains from viridans group streptococci resulted in species-specific clusters for the mitis and the salivarius groups but not for the anginosus group. The identification capacity of pyrosequencing was compared to the biochemical test systems VITEK 2 and Rapid ID 32 Strep. The concordance between pyrosequencing and VITEK 2 was 75%, and for Rapid ID 32 Strep the corresponding figure was 77%. Isolates with discrepant identifications in the three methods were subjected to entire rnpB DNA sequence analysis that confirmed the identifications by pyrosequencing. In conclusion, pyrosequencing analysis of the rnpB gene can reliably identify Streptococcus species with high resolution.
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Affiliation(s)
- Asa Innings
- Department of Clinical Microbiology, Uppsala University Hospital, SE-751 85 Uppsala, Sweden
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Shibata Y, Kawada M, Nakano Y, Toyoshima K, Yamashita Y. Identification and characterization of an autolysin-encoding gene of Streptococcus mutans. Infect Immun 2005; 73:3512-20. [PMID: 15908380 PMCID: PMC1111888 DOI: 10.1128/iai.73.6.3512-3520.2005] [Citation(s) in RCA: 52] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
We identified a gene (atlA) encoding autolytic activity from Streptococcus mutans Xc. The AtlA protein predicted to be encoded by atlA is composed of 979 amino acids with a molecular weight of 107,279 and has a conserved beta-1,4-N-acetylmuramidase (lysozyme) domain in the C-terminal portion. Sodium dodecyl sulfate extracts of strain Xc showed two major bacteriolytic bands with molecular masses of 107 and 79 kDa, both of which were absent from a mutant with inactivated atlA. Western blot analysis revealed that the 79-kDa band was derived from the 107-kDa peptide by cleavage of its N-terminal portion. The inactivation of atlA resulted in a marked decrease in autolysis and the formation of very long chains of cells compared to the case for the parent strain. Although both the parent and mutant strains formed biofilms in the presence of sucrose, the biofilms formed by the mutant had a sponge-like architecture with large gaps and contained 30% less biomass than those formed by the parent strain. Furthermore, strain Xc formed glucose-dependent, loose biofilms in the absence of sucrose, but the mutant lost this ability. These results suggest that AtlA may play an important role in biofilm formation by S. mutans. The antibody produced against the C-terminal peptide containing the beta-1,4-N-acetylmuramidase domain drastically inhibited the autolytic activity of strain Xc. This inhibition was specific among the oral streptococci to S. mutans. These results indicate that the catalytic domain of AtlA is located at the C terminus, suggesting that further characterization of this domain may provide a means to control cariogenic dental plaque formation.
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Affiliation(s)
- Yukie Shibata
- Department of Preventive Dentistry, Kyushu University Faculty of Dental Science, 3-1-1 Maidashi, Higashi-ku, Fukuoka 812-8582, Japan
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Wang B, Kuramitsu HK. Inducible antisense RNA expression in the characterization of gene functions in Streptococcus mutans. Infect Immun 2005; 73:3568-76. [PMID: 15908386 PMCID: PMC1111864 DOI: 10.1128/iai.73.6.3568-3576.2005] [Citation(s) in RCA: 36] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/12/2004] [Revised: 01/06/2005] [Accepted: 02/15/2005] [Indexed: 01/30/2023] Open
Abstract
In order to examine gene function in Streptococcus mutans, we have recently initiated an antisense RNA strategy. Toward this end, we have now constructed and evaluated three Escherichia coli-S. mutans shuttle expression vectors with the fruA and scrB promoters from S. mutans, as well as the tetR-controlled tetO promoter from Staphylococcus aureus. Among these, the tetO/tetR system proved to be the most tightly controlled promoter. By using this shuttle plasmid system, modulation of gene function by inducible antisense RNA expression was demonstrated for comC antisense fragments of different sizes as well as for distinct gtfB antisense fragments. It was demonstrated that the size, but not the relative position, of an antisense DNA fragment is important in mediating the antisense phenomenon. Furthermore, by constructing and screening random DNA libraries with the tet expression shuttle system, 78 growth-retarded transformants harboring antisense DNA fragments were also identified. Almost all of them corresponded to homologous essential genes in other bacteria. In addition, a novel essential gene, the coaE gene, encoding dephospho-coenzyme A kinase, which is involved in the final step of coenzyme A catabolism in S. mutans, was identified and characterized. These results suggest that the antisense RNA strategy can be useful for identifying novel essential genes in S. mutans bacteria as well as further characterizing the physiology (including potential virulence factors) of these organisms.
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Affiliation(s)
- Bing Wang
- Department of Oral Biology, State University of New York at Buffalo, 3435 Main Street, Buffalo, NY 14214, USA
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Bosshard PP, Abels S, Altwegg M, Böttger EC, Zbinden R. Comparison of conventional and molecular methods for identification of aerobic catalase-negative gram-positive cocci in the clinical laboratory. J Clin Microbiol 2004; 42:2065-73. [PMID: 15131171 PMCID: PMC404636 DOI: 10.1128/jcm.42.5.2065-2073.2004] [Citation(s) in RCA: 95] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
Over a period of 18 months we have evaluated the use of 16S ribosomal DNA (rDNA) sequence analysis as a means of identifying aerobic catalase-negative gram-positive cocci in the clinical laboratory. A total of 171 clinically relevant strains were studied. The results of molecular analyses were compared with those obtained with a commercially available phenotypic identification system (API 20 Strep system; bioMérieux sa, Marcy l'Etoile, France). Phenotypic characterization identified 67 (39%) isolates to the species level and 32 (19%) to the genus level. Seventy-two (42%) isolates could not be discriminated at any taxonomic level. In comparison, 16S rDNA sequencing identified 138 (81%) isolates to the species level and 33 (19%) to the genus level. For 42 of 67 isolates assigned to a species with the API 20 Strep system, molecular analyses yielded discrepant results. Upon further analysis it was concluded that among the 42 isolates with discrepant results, 16S rDNA sequencing was correct for 32 isolates, the phenotypic identification was correct for 2 isolates, and the results for 8 isolates remained unresolved. We conclude that 16S rDNA sequencing is an effective means for the identification of aerobic catalase-negative gram-positive cocci. With the exception of Streptococcus pneumoniae and beta-hemolytic streptococci, we propose the use of 16S rDNA sequence analysis if adequate species identification is of concern.
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Affiliation(s)
- P P Bosshard
- Institute of Medical Microbiology, University of Zürich, 8028 Zurich, Switzerland.
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16
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Drancourt M, Roux V, Fournier PE, Raoult D. rpoB gene sequence-based identification of aerobic Gram-positive cocci of the genera Streptococcus, Enterococcus, Gemella, Abiotrophia, and Granulicatella. J Clin Microbiol 2004; 42:497-504. [PMID: 14766807 PMCID: PMC344509 DOI: 10.1128/jcm.42.2.497-504.2004] [Citation(s) in RCA: 131] [Impact Index Per Article: 6.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/29/2023] Open
Abstract
We developed a new molecular tool based on rpoB gene (encoding the beta subunit of RNA polymerase) sequencing to identify streptococci. We first sequenced the complete rpoB gene for Streptococcus anginosus, S. equinus, and Abiotrophia defectiva. Sequences were aligned with these of S. pyogenes, S. agalactiae, and S. pneumoniae available in GenBank. Using an in-house analysis program (SVARAP), we identified a 740-bp variable region surrounded by conserved, 20-bp zones and, by using these conserved zones as PCR primer targets, we amplified and sequenced this variable region in an additional 30 Streptococcus, Enterococcus, Gemella, Granulicatella, and Abiotrophia species. This region exhibited 71.2 to 99.3% interspecies homology. We therefore applied our identification system by PCR amplification and sequencing to a collection of 102 streptococci and 60 bacterial isolates belonging to other genera. Amplicons were obtained in streptococci and Bacillus cereus, and sequencing allowed us to make a correct identification of streptococci. Molecular signatures were determined for the discrimination of closely related species within the S. pneumoniae-S. oralis-S. mitis group and the S. agalactiae-S. difficile group. These signatures allowed us to design a S. pneumoniae-specific PCR and sequencing primer pair.
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Affiliation(s)
- Michel Drancourt
- Unité des Rickettsies, IFR 48, Faculté de Médecine, Université de la Méditerranée, Marseille, France
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17
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Salaün L, Snyder LA, Saunders NJ. Adaptation by phase variation in pathogenic bacteria. ADVANCES IN APPLIED MICROBIOLOGY 2003; 52:263-301. [PMID: 12964248 DOI: 10.1016/s0065-2164(03)01011-6] [Citation(s) in RCA: 34] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/29/2023]
Affiliation(s)
- Laurence Salaün
- Bacterial Pathogenesis and Functional Genomics Group, Sir William Dunn School of Pathology, University of Oxford, Oxford OX1 3RE, United Kingdom
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18
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Banas JA, Vickerman MM. Glucan-binding proteins of the oral streptococci. CRITICAL REVIEWS IN ORAL BIOLOGY AND MEDICINE : AN OFFICIAL PUBLICATION OF THE AMERICAN ASSOCIATION OF ORAL BIOLOGISTS 2003; 14:89-99. [PMID: 12764072 DOI: 10.1177/154411130301400203] [Citation(s) in RCA: 228] [Impact Index Per Article: 10.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/17/2022]
Abstract
The synthesis of extracellular glucan is an integral component of the sucrose-dependent colonization of tooth surfaces by species of the mutans streptococci. In investigators' attempts to understand the mechanisms of plaque biofilm development, several glucan-binding proteins (GBPs) have been discovered. Some of these, the glucosyltransferases, catalyze the synthesis of glucan, whereas others, designated only as glucan-binding proteins, have affinities for different forms of glucan and contribute to aspects of the biology of their host organisms. The functions of these latter glucan-binding proteins include dextran-dependent aggregation, dextranase inhibition, plaque cohesion, and perhaps cell wall synthesis. In some instances, their glucan-binding domains share common features, whereas in others the mechanism for glucan binding remains unknown. Recent studies indicate that at least some of the glucan-binding proteins modulate virulence and some can act as protective immunogens within animal models. Overall, the multiplicity of GBPs and their aforementioned properties are testimonies to their importance. Future studies will greatly advance the understanding of the distribution, function, and regulation of the GBPs and place into perspective the facets of their contributions to the biology of the oral streptococci.
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Affiliation(s)
- J A Banas
- Center for Immunology and Microbial Disease, Albany Medical College, NY 12208, USA.
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19
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Stinson MW, Alder S, Kumar S. Invasion and killing of human endothelial cells by viridans group streptococci. Infect Immun 2003; 71:2365-72. [PMID: 12704106 PMCID: PMC153257 DOI: 10.1128/iai.71.5.2365-2372.2003] [Citation(s) in RCA: 65] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/08/2002] [Revised: 12/18/2002] [Accepted: 01/29/2003] [Indexed: 11/20/2022] Open
Abstract
Colonization of the cardiovascular endothelium by viridans group streptococci can result in infective endocarditis and possibly atherosclerosis; however, the mechanisms of pathogenesis are poorly understood. We investigated the ability of selected oral streptococci to infect monolayers of human umbilical vein endothelial cells (HUVEC) in 50% human plasma and to produce cytotoxicity. Planktonic Streptococcus gordonii CH1 killed HUVEC over a 5-h period by peroxidogenesis (alpha-hemolysin) and by acidogenesis but not by production of protein exotoxins. HUVEC were protected fully by addition of supplemental buffers and bovine liver catalase to the culture medium. Streptococci were also found to invade HUVEC by an endocytic mechanism that was dependent on polymerization of actin microfilaments and on a functional cytoskeleton, as indicated by inhibition with cytochalasin D and nocodazole. Electron microscopy revealed streptococci attached to HUVEC surfaces via numerous fibrillar structures and bacteria in membrane-encased cytoplasmic vacuoles. Following invasion by S. gordonii CH1, HUVEC monolayers showed 63% cell lysis over 4 h, releasing 64% of the total intracellular bacteria into the culture medium; however, the bacteria did not multiply during this time. The ability to invade HUVEC was exhibited by selected strains of S. gordonii, S. sanguis, S. mutans, S. mitis, and S. oralis but only weakly by S. salivarius. Comparison of isogenic pairs of S. gordonii revealed a requirement for several surface proteins for maximum host cell invasion: glucosyltransferase, the sialic acid-binding protein Hsa, and the hydrophobicity/coaggregation proteins CshA and CshB. Deletion of genes for the antigen I/II adhesins, SspA and SspB, did not affect invasion. We hypothesize that peroxidogenesis and invasion of the cardiovascular endothelium by viridans group streptococci are integral events in the pathogenesis of infective endocarditis and atherosclerosis.
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Affiliation(s)
- Murray W Stinson
- Center for Microbial Pathogenesis, Department of Microbiology, School of Medicine and Biomedical Sciences, State University of New York at Buffalo, Buffalo, New York 14214, USA.
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20
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Vickerman MM, Wang M, Baker LJ. An amino acid change near the carboxyl terminus of the Streptococcus gordonii regulatory protein Rgg affects its abilities to bind DNA and influence expression of the glucosyltransferase gene gtfG. MICROBIOLOGY (READING, ENGLAND) 2003; 149:399-406. [PMID: 12624202 DOI: 10.1099/mic.0.25983-0] [Citation(s) in RCA: 16] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/26/2022]
Abstract
The Streptococcus gordonii glucosyltransferase structural gene, gtfG, is located immediately downstream from its positive transcriptional regulatory determinant, rgg. Recent genetic studies have indicated that the 3' end of rgg is involved either directly as a binding site or indirectly, e.g. by playing a role in secondary structure, in the interaction of Rgg with the gtfG promoter. A previously identified spontaneous mutant with a point mutation near the 3' end of rgg had only approximately 25% of the parental level of glucosyltransferase activity. To determine if this decreased activity was due to a change in the DNA binding site of trans-acting Rgg, or due to a change in the Rgg protein itself, complementation analyses and DNA-binding studies were performed. In Rgg-deficient strains, the chromosomal rgg point mutation did not influence the ability of plasmid-borne rgg to increase glucosyltransferase expression. However, plasmids carrying parental rgg were able to increase glucosyltransferase activity and expression of a gtfG promoter fusion to a greater extent than plasmids carrying the mutant allele, indicating that the mutant Rgg protein had decreased activity. The ability of NH(2)-terminal (hexahistidine) tagged proteins to bind to a 107 bp dsDNA fragment corresponding to the region immediately upstream of gtfG was demonstrated by surface plasmon resonance. Despite their differences in activity, both mutant and parental recombinant Rgg proteins bound to this dsDNA, albeit with different strengths. These studies provide insights into functional domains of S. gordonii Rgg which influence glucosyltransferase expression, and may have implications for Rgg-like regulatory proteins in related bacteria.
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Affiliation(s)
- M M Vickerman
- Department of Microbiology and Immunology, School of Medicine, Indiana University, Indianapolis, IN, USA
- Department of Oral Surgery and Hospital Dentistry, School of Dentistry, School of Medicine, Indiana University, Indianapolis, IN, USA
| | - M Wang
- Department of Biochemistry and Molecular Biology, School of Medicine, Indiana University, Indianapolis, IN, USA
| | - L J Baker
- Department of Biochemistry and Molecular Biology, School of Medicine, Indiana University, Indianapolis, IN, USA
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21
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McNab R, Ford SK, El-Sabaeny A, Barbieri B, Cook GS, Lamont RJ. LuxS-based signaling in Streptococcus gordonii: autoinducer 2 controls carbohydrate metabolism and biofilm formation with Porphyromonas gingivalis. J Bacteriol 2003; 185:274-84. [PMID: 12486064 PMCID: PMC141908 DOI: 10.1128/jb.185.1.274-284.2003] [Citation(s) in RCA: 258] [Impact Index Per Article: 12.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
Communication based on autoinducer 2 (AI-2) is widespread among gram-negative and gram-positive bacteria, and the AI-2 pathway can control the expression of genes involved in a variety of metabolic pathways and pathogenic mechanisms. In the present study, we identified luxS, a gene responsible for the synthesis of AI-2, in Streptococcus gordonii, a major component of the dental plaque biofilm. S. gordonii conditioned medium induced bioluminescence in an AI-2 reporter strain of Vibrio harveyi. An isogenic mutant of S. gordonii, generated by insertional inactivation of the luxS gene, was unaffected in growth and in its ability to form biofilms on polystyrene surfaces. In contrast, the mutant strain failed to induce bioluminescence in V. harveyi and was unable to form a mixed species biofilm with a LuxS-null strain of the periodontal pathogen Porphyromonas gingivalis. Complementation of the luxS mutation in S. gordonii restored normal biofilm formation with the luxS-deficient P. gingivalis. Differential display PCR demonstrated that the inactivation of S. gordonii luxS downregulated the expression of a number of genes, including gtfG, encoding glucosyltransferase; fruA, encoding extracellular exo-beta-D-fructosidase; and lacD encoding tagatose 1,6-diphosphate aldolase. However, S. gordonii cell surface expression of SspA and SspB proteins, previously implicated in mediating adhesion between S. gordonii and P. gingivalis, was unaffected by inactivation of luxS. The results suggest that S. gordonii produces an AI-2-like signaling molecule that regulates aspects of carbohydrate metabolism in the organism. Furthermore, LuxS-dependent intercellular communication is essential for biofilm formation between nongrowing cells of P. gingivalis and S. gordonii.
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Affiliation(s)
- Roderick McNab
- Department of Microbiology, Eastman Dental Institute, University College, London WC1 8LD, United Kingdom.
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22
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Takahashi Y, Ruhl S, Yoon JW, Sandberg AL, Cisar JO. Adhesion of viridans group streptococci to sialic acid-, galactose- and N-acetylgalactosamine-containing receptors. ORAL MICROBIOLOGY AND IMMUNOLOGY 2002; 17:257-62. [PMID: 12121477 DOI: 10.1034/j.1399-302x.2002.170409.x] [Citation(s) in RCA: 35] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/23/2022]
Abstract
The binding of 10 viridans group streptococci to sialic acid-, galactose (Gal)- and N-acetylgalactosamine (GalNAc)-containing receptors was defined by analysis of the interactions between these bacteria and structurally defined glycoconjugates, host cells and other streptococci. All interactions with sialic acid-containing receptors were Ca(2+)-independent as they were not affected by ethyleneglycoltetraacetic acid (EGTA), whereas all interactions with Gal- and GalNAc-containing receptors were Ca(2+)-dependent. Recognition of sialic acid-, Gal- and GalNAc-containing receptors varied widely among the strains examined, in a manner consistent with the association of each of the three lectin-like activities with a different bacterial cell surface component.
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Affiliation(s)
- Y Takahashi
- Oral Infection and Immunity Branch, National Institute of Dental and Craniofacial Research, National Institutes of Health, Bethesda, MD 20892, USA
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23
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Vickerman MM, Minick PE. Genetic analysis of the rgg-gtfG junctional region and its role in Streptococcus gordonii glucosyltransferase activity. Infect Immun 2002; 70:1703-14. [PMID: 11895932 PMCID: PMC127849 DOI: 10.1128/iai.70.4.1703-1714.2002] [Citation(s) in RCA: 16] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
Glucans synthesized by glucosyltransferase enzymes of oral streptococci facilitate bacterial accumulation on surfaces. The Streptococcus gordonii glucosyltransferase gene, gtfG, is positively regulated by rgg, which encodes a putative cytoplasmic protein. The gtfG promoter and ribosomal binding sequences are located within a DNA inverted repeat immediately downstream of rgg. Polycistronic rgg-gtfG as well as rgg- and gtfG-specific transcripts are associated with this chromosomal region. Previous studies have shown that the rgg product acts in trans near the gtfG promoter to increase the level of gtfG transcript, but it does not affect the level of rgg-gtfG transcript. To further analyze regulation by rgg, a series of strain Challis derivatives was constructed and glucosyltransferase activities were determined. Strains in which rgg was separated from gtfG by integrated vector sequences had decreased levels of glucosyltransferase activity; plasmid-borne rgg could not increase activity to parental levels. As expected, strains with chromosomal deletions involving the rgg structural gene and either the rgg or gtfG promoter also showed decreased glucosyltransferase activity. Plasmid-borne rgg could increase glucosyltransferase activity only in strains which had a 36-bp chromosomal region beginning 72 nucleotides upstream of the gtfG transcriptional start site. Results suggest that these nucleotides, located within the 3' end of rgg, are necessary, either by direct involvement in binding or by indirectly affecting secondary structure, for Rgg to increase glucosyltransferase activity. Surprisingly, the presence of the rgg promoter upstream of this 36-bp region significantly increased the effects of plasmid-borne rgg. Implications for glucosyltransferase regulation and applicability to other rgg-like determinants are considered.
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Affiliation(s)
- M M Vickerman
- Department of Oral Surgery and Hospital Dentistry, School of Dentistry, Indiana University, Indianapolis, Indiana 46202, USA.
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Vickerman MM, Mather NM, Minick PE, Edwards CA. Initial characterization of the Streptococcus gordonii htpX gene. ORAL MICROBIOLOGY AND IMMUNOLOGY 2002; 17:22-31. [PMID: 11860552 DOI: 10.1046/j.0902-0055.2001.00000.x] [Citation(s) in RCA: 12] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/20/2022]
Abstract
Examination of the Streptococcus gordonii chromosomal region, which lies immediately upstream of the glucosyltransferase positive regulatory determinant rgg, revealed two open reading frames. Based on nucleotide sequences, these genes were similar to the Listeria monocytogenes lemA gene, which is involved in antigen presentation, and the Escherichia coli htpX heat shock gene, which has an unknown function. Northern hybridization analysis indicated that S. gordonii lemA and htpX genes were associated with a ca. 1.7-kb polycistronic transcript. Although levels of the lemA/htpX transcript did not increase in response to heat to levels seen with dnaK controls, insertional inactivation of htpX resulted in changes in adhesiveness, cellular morphology and detergent-extractable surface antigens in cells grown at 41 degrees C, implying that htpX may be involved in surface protein expression. Insertional inactivation of lemA and htpX indicated that, despite their proximity to rgg and the structural gene, gtfG, these upstream genes do not affect S. gordonii glucosyltransferase activity.
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Affiliation(s)
- M M Vickerman
- Department of Oral Surgery and Hospital Dentistry, School of Dentistry, Indiana University, 1121 West Michigan Street, Indianapolis, IN 46202, USA
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25
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Vickerman MM, Minick PE, Mather NM. Characterization of the Streptococcus gordonii chromosomal region immediately downstream of the glucosyltransferase gene. MICROBIOLOGY (READING, ENGLAND) 2001; 147:3061-70. [PMID: 11700356 DOI: 10.1099/00221287-147-11-3061] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/18/2022]
Abstract
The Streptococcus gordonii glucosyltransferase gene, gtfG, is positively regulated by the upstream determinant rgg. In the present study, two ORFs, transcribed on the opposite DNA strand, were identified immediately downstream of gtfG. The first, designated dsg, shares a convergent putative transcriptional terminator with gtfG, and encodes a predicted 46 kDa transmembrane protein similar to the Yersinia enterocolitica TrsA involved in polysaccharide biosynthesis. Insertional inactivation of dsg resulted in only approximately approximately 60% of the parental level of glucosyltransferase activity. The 870 bp gene 5' to dsg is similar to the gtfG regulatory determinant. Designated rggD, this rgg-like determinant downstream of gtfG encodes a putative 33.6 kDa cytoplasmic protein. Despite their sequence similarity, the functions of rgg and rggD appear specific. Strains in which rggD was insertionally inactivated and strains containing plasmid-borne rggD had parental levels of glucosyltransferase activity. Northern blot hybridization analyses showed approximately 1.3 kb dsg-specific and approximately 1.0 kb rggD-specific mRNA transcripts associated with this region; no polycistronic transcript was observed. Although rgg-like gene products have been demonstrated to function as positive transcriptional regulators of adjacent genes in several streptococcal species, Northern blot analysis suggested that rggD did not influence the transcription of dsg or the divergent downstream ylbN-like determinant under the conditions in the present study. Comparison of this S. gordonii chromosome region to other streptococcal genomes, which do not contain the rgg/rggD-flanked region involved in glucan synthesis, raised intriguing possibilities about the origins of this chromosomal region, and also suggested that rggD might regulate a distally located gene.
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Affiliation(s)
- M M Vickerman
- Department of Oral Surgery and Hospital Dentistry, School of Dentistry, Indiana University, Indianapolis, IN 46202, USA.
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Tomita Y, Watanabe T, Takeuchi T, Nanbu A, Shinozaki N, Ikemi T, Fukushima K. Effects of surfactants on glucosyltransferase production and in vitro sucrose-dependent colonization by Streptococcus mutans. Arch Oral Biol 1998; 43:735-40. [PMID: 9783828 DOI: 10.1016/s0003-9969(98)00065-x] [Citation(s) in RCA: 14] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/09/2023]
Abstract
The presence of Tween 80 in media was associated with a significant increase in three glucosyltransferases(GTFs)(I, SI and S), especially GTF-I, produced by Streptococcus mutans strain PS14, indicating that the surfactant is a major cause of the enhanced GTF production observed in cultures in M4 medium. Lecithin and Tween 20 also enhanced GTF-I production, while Triton X-100 depressed it. At a lot concentration of 0.00125%, Tween 80 enhanced markedly only GTF-I production and its effect reached maximum at a concentration of 0.0025%. Water-insoluble glucan synthesis and artificial plaque formation (in vitro sucrose-dependent colonization) by PS14 were significantly enhanced by the addition of Tween 80 at concentrations over 0.00125%. These results suggest that surfactants might vary the cariogenic potential of Strep. mutans even at low concentrations.
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Affiliation(s)
- Y Tomita
- Department of Operative Dentistry, Nihon University School of Dentistry at Matsudo, Chiba, Japan
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27
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Abstract
This review explains some of the basic techniques of molecular biology and their application to the study of oral streptococci. Examples of how these techniques have furthered the understanding of streptococcal colonization in health and disease are discussed along with approaches to controlling dental caries that have been made plausible by the knowledge gained using these techniques.
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Affiliation(s)
- N Jacques
- Institute of Dental Research, Sydney
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28
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Bowden GH, Hamilton IR. Survival of oral bacteria. CRITICAL REVIEWS IN ORAL BIOLOGY AND MEDICINE : AN OFFICIAL PUBLICATION OF THE AMERICAN ASSOCIATION OF ORAL BIOLOGISTS 1998; 9:54-85. [PMID: 9488248 DOI: 10.1177/10454411980090010401] [Citation(s) in RCA: 168] [Impact Index Per Article: 6.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 02/06/2023]
Abstract
The global distribution of individual species of oral bacteria demonstrates their ability to survive among their human hosts. Such an ubiquitous existence is the result of efficient transmission of strains and their persistence in the oral environment. Genetic analysis has identified specific clones of pathogenic bacteria causing infection. Presumably, these express virulence-associated characteristics enhancing colonization and survival in their hosts. A similar situation may occur with the oral resident flora, where genetic variants may express specific phenotypic characteristics related to survival. Survival in the mouth is enhanced by dental plaque formation, where persistence is associated with the bacteria's capacity not only to adhere and grow, but also to withstand oxygen, wide fluctuations in pH and carbohydrate concentration, and a diverse array of microbial interactions. Streptococcus mutans has been discussed as a 'model' organism possessing the biochemical flexibility that permits it to persist and dominate the indigenous microflora under conditions of stress.
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Affiliation(s)
- G H Bowden
- Department of Oral Biology, Faculty of Dentistry, University of Manitoba, Winnipeg, Canada
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29
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Poyart C, Quesne G, Coulon S, Berche P, Trieu-Cuot P. Identification of streptococci to species level by sequencing the gene encoding the manganese-dependent superoxide dismutase. J Clin Microbiol 1998; 36:41-7. [PMID: 9431917 PMCID: PMC124804 DOI: 10.1128/jcm.36.1.41-47.1998] [Citation(s) in RCA: 237] [Impact Index Per Article: 9.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/22/1997] [Accepted: 09/25/1997] [Indexed: 02/05/2023] Open
Abstract
We have used a PCR assay based on the use of degenerate primers in order to characterize an internal fragment (sodA(int)) representing approximately 85% of the genes encoding the manganese-dependent superoxide dismutase in various streptococcal type strains (S. acidominimus, S. agalactiae, S. alactolyticus, S. anginosus, S. bovis, S. constellatus, S. canis, S. cricetus, S. downei, S. dysgalactiae, S. equi subsp. equi, S. equi subsp. zooepidemicus, S. equinus, S. gordonii, S. iniae, S. intermedius, S. mitis, S. mutans, S. oralis, S. parasanguis, S. pneumoniae, S. porcinus, S. pyogenes, S. salivarius, S. sanguis, S. sobrinus, S. suis, S. thermophilus, and S. vestibularis). Phylogenetic analysis of these sodA(int) fragments yields an evolutionary tree having a topology similar to that of the tree constructed with the 16S rRNA sequences. We have shown that clinical isolates could be identified by determining the positions of their sodA(int) fragments on the phylogenetic tree of the sodA(int) fragments of the type species. We propose this method for the characterization of strains that cannot be assigned to a species on the basis of their conventional phenotypic reactions.
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Affiliation(s)
- C Poyart
- Laboratoire Mixte Pasteur-Necker de Recherche sur les Streptocoques et Streptococcies, Faculté de Médecine Necker-Enfants Malades, Paris, France
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30
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Vickerman MM, Clewell DB. Regulation of Streptococcus gordonii glucosyltransferase. ADVANCES IN EXPERIMENTAL MEDICINE AND BIOLOGY 1997; 418:661-4. [PMID: 9331738 DOI: 10.1007/978-1-4899-1825-3_154] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.0] [Reference Citation Analysis] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 02/05/2023]
Affiliation(s)
- M M Vickerman
- Department of Microbiology and Immunology, School of Medicine, University of Michigan, Ann Arbor, USA
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31
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Garnier F, Gerbaud G, Courvalin P, Galimand M. Identification of clinically relevant viridans group streptococci to the species level by PCR. J Clin Microbiol 1997; 35:2337-41. [PMID: 9276413 PMCID: PMC229965 DOI: 10.1128/jcm.35.9.2337-2341.1997] [Citation(s) in RCA: 69] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/05/2023] Open
Abstract
A PCR assay that allows identification of clinically relevant viridans group streptococci (Streptococcus gordonii, S. mitis, S. mutans, S. oralis, S. salivarius, and S. sanguis) to the species level and identification of milleri group streptococci (S. anginosus, S. constellatus, and S. intermedius) to the group level was developed. This assay was based on specific amplification of internal fragments of genes encoding D-alanine:D-alanine ligases which are species specific and ubiquitous in prokaryotes possessing peptidoglycan. The specificity of this assay was tested on 9 reference strains and 91 characterized clinical isolates. This assay offers a specific and rapid alternative to phenotypic or DNA-DNA hybridization methods for identification of clinically relevant viridans group streptococci.
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Affiliation(s)
- F Garnier
- Unité des Agents Antibactériens and National Reference Center for Antibiotics, Institut Pasteur, Paris, France
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32
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Vickerman MM, Clewell DB. Deletions in the carboxyl-terminal region of Streptococcus gordonii glucosyltransferase affect cell-associated enzyme activity and sucrose-associated accumulation of growing cells. Appl Environ Microbiol 1997; 63:1667-73. [PMID: 9143100 PMCID: PMC168460 DOI: 10.1128/aem.63.5.1667-1673.1997] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/04/2023] Open
Abstract
The single glucosyltransferase (GTF) of Streptococcus gordonii Challis CH1 makes alpha 1,3- and alpha 1,6-linked glucans from sucrose. The GTF carboxyl-terminal region has six direct repeats thought to be involved in glucan binding. Strains with defined mutations in this region have been described recently (M. M. Vickerman, M. C. Sulavik, P. E. Minick, and D. B. Clewell, Infect. Immun. 64:5117-5128, 1996). Strain CH107 GTF has three internal direct repeats deleted; the 59 carboxyl-terminal amino acids are identical to those of the parental strain. This deletion resulted in decreased enzyme activity but did not affect the amount of cell-associated GTF protein. The GTFs of strains CH2RPE and CH4RPE have six and eight direct repeats, respectively, but are both missing the 14 carboxyl-terminal amino acids. Strain CH2RPE had significantly decreased levels of cell-associated GTF; this decrease was not obviated by the increased number of direct repeats in strain CH4RPE. Thus, the carboxyl-terminal amino acids appeared to influence the amount of cell-associated GTF more than the direct repeats. The qualitative and quantitative differences in the GTFs did not affect the abilities of these strains to accumulate on hydroxyapatite beads in the absence of sucrose. However, when sucrose was added as a substrate for GTF, the mutant strains were unable to accumulate on these surfaces to the same extent as the parent. These differences in sucrose-associated accumulation may be due to changes in the nature of the glucans produced by the different enzymes and/or cohesive interactions between these glucans and the GTF on the surfaces of the growing streptococci.
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Affiliation(s)
- M M Vickerman
- Department of Microbiology and Immunology, School of Medicine, University of Michigan, Ann Arbor 48109, USA.
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Vickerman MM, Jones GW, Clewell DB. Molecular analysis of representative Streptococcus gordonii Spp phase variants reveals no differences in the glucosyltransferase structural gene, gtfG. ORAL MICROBIOLOGY AND IMMUNOLOGY 1997; 12:82-90. [PMID: 9227131 DOI: 10.1111/j.1399-302x.1997.tb00622.x] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 02/04/2023]
Abstract
Streptococcus gordonii glucosyltransferase polymerizes sucrose to form glucans, which confer a hard, sucrose-promoted phenotype (Spp+) to colonies on sucrose agar plates. The glucosyltransferase structural gene, gtfG, is positively regulated by the upstream determinant, rgg. Strain Challis undergoes a spontaneous, reversible phase variation between high (Spp+) and low (Spp-) levels of glucosyltransferase activity. Representative strains were examined to gain insights into the basis of glucosyltransferase phase variation. Western blots indicated that the level of glucosyltransferase activity was related to the amount of extracellular glucosyltransferase protein produced by Spp- and Spp+ strains. The nucleotide sequence of rgg and gtfG of the Spp- strain CH97 was found to be identical to that of the Spp+ parent, indicating that DNA differences in these regions are not the basis for glucosyltransferase phase variation. Indeed, 13C-NMR spectroscopy suggested that glucans synthesized by strain CH97 glucosyltransferase were similar to those synthesized by glucosyltransferase of the Spp+ parental strain, indicating a quantitative rather than qualitative change. However, one Spp- strain, CH1C1, had a point mutation in rgg; replacement of the parent rgg with the CH1C1 allele resulted in decreased levels of glucosyltransferase protein and activity. The results indicate that glucosyltransferase phase variation can occur in more than one way, and suggest that glucosyltransferase regulation may involve distally located regulatory gene(s) that affect rgg and/or gtfG expression.
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Affiliation(s)
- M M Vickerman
- Department of Microbiology and Immunology, School of Medicine, Ann Arbor 48109-0620, USA
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34
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Vickerman MM, Sulavik MC, Nowak JD, Gardner NM, Jones GW, Clewell DB. Nucleotide sequence analysis of the Streptococcus gordonii glucosyltransferase gene, gtfG. DNA SEQUENCE : THE JOURNAL OF DNA SEQUENCING AND MAPPING 1997; 7:83-95. [PMID: 9063645 DOI: 10.3109/10425179709020155] [Citation(s) in RCA: 39] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 02/03/2023]
Abstract
Streptococcus gordonii has an extracellular glucosyltransferase (GTF) that polymerizes the glucose moiety of sucrose to form both water-soluble and water-insoluble glucans. Whereas multiple gtf genes have been identified in strains of mutans streptococci and Streptococcus salivarius, a single gene, designated gtfG, encodes the GTF of S. gordonii Challis. gtfG is also unique among the characterized gtfs in that it has a described regulatory determinant, rgg. Furthermore, the GTF activity in S. gordonii undergoes reversible phase variation between high and low levels. In order to gain insight into this novel GTF system, the nucleotide sequence of gtfG was determined and found to consist of a 4,734 base pair open reading frame encoding a protein with a deduced molecular weight of ca. 174,000. gtfG was similar to other sequenced gtfs with a conserved signal sequence followed by a ca. 600-bp region distinctive for gtfG, a conserved region encoding a putative catalytic active site and a series of six direct repeats in the carboxyl terminal region implicated in glucan binding. Although comparison of gtfG to other gtfs did not show a basis for the primer-independence of the encoded enzyme or the nature of the glucan products, the gtfG sequence data provide an important basis for further studies of these enzymes.
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Affiliation(s)
- M M Vickerman
- Department of Microbiology and Immunology, School of Medicine, University of Michigan, Ann Arbor 48109-0620, USA.
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35
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Vickerman MM, Sulavik MC, Minick PE, Clewell DB. Changes in the carboxyl-terminal repeat region affect extracellular activity and glucan products of Streptococcus gordonii glucosyltransferase. Infect Immun 1996; 64:5117-28. [PMID: 8945555 PMCID: PMC174497 DOI: 10.1128/iai.64.12.5117-5128.1996] [Citation(s) in RCA: 35] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/03/2023] Open
Abstract
Glucans produced by the glucosyltransferase (GTF) of Streptococcus gordonii confer a hard, cohesive phenotype (Spp+) on colonies grown on sucrose agar plates. S. gordonii strains with specific mutations in the region of gtfG that encodes the GTF carboxyl terminus were characterized. In the parental strain Challis CH1, this region included a series of six direct repeats thought to function in glucan binding. The spontaneous mutant strain CH107 had a 585-bp deletion resulting in the loss of three internal direct repeats. Insertional mutagenesis was used to construct strain CH2RPE, which had the parental repeat region but was missing 14 carboxyl-terminal amino acids. The similarly constructed strain CH4RPE had an in-frame addition of 390 nucleotides encoding two additional direct repeats. Although strains CH1, CH2RPE, and CH4RPE all had similar levels of extracellular GTF activity, strain CH107 had less than 15% of the parental activity; however, Western blots (immunoblots) indicated that the amounts of extracellular GTF protein in all four strains were similar. 13C NMR analyses indicated that partially purified GTFs from the Spp+ strains CH1, CH2RPE, and CH4RPE all produced glucans with similar ratios of alpha1,6 and alpha1,3 glucosidic linkages, whereas the Spp- strain CH107 GTF produced primarily alpha1,6-linked glucans. Transformation of strain CH107 with pAMS57, which carries the gtfG positive regulatory determinant, rgg, increased the amount of GTF activity and GTF antibody-reactive protein ca. fivefold but did not confer a hard colony phenotype on sucrose agar plates, suggesting that the type of glucan product affects the sucrose-promoted colony phenotype.
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Affiliation(s)
- M M Vickerman
- Department of Microbiology and Immunology, School of Medicine, University of Michigan, Ann Arbor 48109, USA.
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36
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Sulavik MC, Clewell DB. Rgg is a positive transcriptional regulator of the Streptococcus gordonii gtfG gene. J Bacteriol 1996; 178:5826-30. [PMID: 8824637 PMCID: PMC178431 DOI: 10.1128/jb.178.19.5826-5830.1996] [Citation(s) in RCA: 48] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/02/2023] Open
Abstract
The Streptococcus gordonii (Challis) glucosyltransferase-encoding determinant gtfG is regulated by the product of the adjacent gene rgg. Results of analyses described here showed that in both S. gordonii and Escherichia coli Rgg is a positive transcriptional regulator of glucosyltransferase expression. In addition, the transcriptional start sites of both gtfG and rgg were determined.
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Affiliation(s)
- M C Sulavik
- Department of Microbiology and Immunology, School of Medicine, University of Michigan, Ann Arbor 48109, USA
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37
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Jones GW, Clewell DB, Charles LG, Vickerman MM. Multiple phase variation in haemolytic, adhesive and antigenic properties of Streptococcus gordonii. MICROBIOLOGY (READING, ENGLAND) 1996; 142 ( Pt 1):181-189. [PMID: 8581164 DOI: 10.1099/13500872-142-1-181] [Citation(s) in RCA: 15] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/31/2023]
Abstract
Streptococcus gordonii gave rise to beta-haemolytic variants (Bhp+ for beta-haemolysin production) at frequencies of 10(-4)-10(-3) on agar medium containing washed horse erythrocytes. Bhp+ variants reverted to the wild-type alpha-haemolytic phenotype (Bhp-) at the same frequencies. There was a significant probability (> or = 0.1) that phase variation in Bhp and phase variation in the previously described Spp (sucrose promoted phenotype) would occur concomitantly, but there was no correlation between these phenotypes. There was evidence also of independent phase variation in adhesion to saliva-coated hydroxyapatite (Asp for adhesion to salivary pellicles), in lactose-sensitive coaggregation (Cls for coaggregation, lactose-sensitive) and in the concentrations of particular cell surface antigens (Cap for cell antigen profile) in strains that had undergone phase changes in Spp and/or Bhp. Phase variation in all these phenotypes were transitions between high and low levels of activity and each appeared to occur as an independent event. Significant associations (P << 0.0001 by contingency table analysis) between particular phenotypes such as Bhp and Asp and between Asp, Cls and Cap phenotypes, however, were apparent. The results suggest that S. gordonii cells become predisposed to phase variation and that the resulting independent phenotypic changes may give rise to phenotypically diverse streptococcal populations able to accommodate rapid and transient environmental changes in the mouth.
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Affiliation(s)
- G W Jones
- Department of Microbiology and Immunology, The Medical School
| | - D B Clewell
- Department of Biologic and Materials Sciences, School of Dentistry, University of Michigan, Ann Arbor, Ml 48109, USA
- Department of Microbiology and Immunology, The Medical School
| | - L G Charles
- Department of Microbiology and Immunology, The Medical School
| | - M M Vickerman
- Department of Microbiology and Immunology, The Medical School
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38
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Vickerman MM, Sulavik MC, Clewell DB. Oral streptococci with genetic determinants similar to the glucosyltransferase regulatory gene, rgg. Infect Immun 1995; 63:4524-7. [PMID: 7591096 PMCID: PMC173645 DOI: 10.1128/iai.63.11.4524-4527.1995] [Citation(s) in RCA: 16] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/26/2023] Open
Abstract
The Streptococcus gordonii Challis glucosyltransferase structural gene, gtfG, is positively regulated by the upstream gene, rgg, the only described gtf regulatory determinant in oral streptococci. Southern hybridization analyses indicated that rgg-like and gtfG-like determinants were present on the same HindIII fragment in strains of S. gordonii, Streptococcus sanguis, and Streptococcus oralis, whereas no rgg-like determinants were detected in mutans streptococci, Streptococcus mitis, and Streptococcus salivarius.
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Affiliation(s)
- M M Vickerman
- Department of Microbiology and Immunology, School of Medicine, University of Michigan, Ann Arbor 48109, USA
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39
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Vickerman MM, Jones GW. Sucrose-dependent accumulation of oral streptococci and their adhesion-defective mutants on saliva-coated hydroxyapatite. ORAL MICROBIOLOGY AND IMMUNOLOGY 1995; 10:175-82. [PMID: 7567067 DOI: 10.1111/j.1399-302x.1995.tb00139.x] [Citation(s) in RCA: 14] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/26/2023]
Abstract
The adhesion and accumulation of oral streptococci on saliva-coated hydroxyapatite was examined in strains representing species that appear in initial plaque (Streptococcus sanguise FC1 and Streptococcus oralis C5) and in more mature plaque (Streptococcus gordonii G9B). Washed cells of strains FC1 and C5 did not attach better to saliva-coated hydroxyapatite than did strain G9B, suggesting that the degree of initial adhesiveness does not alone account for the temporal appearance of these bacteria in dental plaque. Growing cells of each strain were also examined for their ability to accumulate on saliva-coated hydroxyapatite. The addition of sucrose to the medium promoted the accumulation of strain G9B more than it promoted the accumulation of strains FC1 and C5. Sucrose also enhanced the accumulation of adhesion-defective mutants of each strain to levels similar to those of the respective parent strains. These results suggest that sucrose-dependent accumulation may facilitate the colonization of the tooth surface by these species of oral streptococci when adhesion is limited by reduced bacterial adhesiveness or limited pellicle-binding sites.
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Affiliation(s)
- M M Vickerman
- Department of Biologic and Materials Sciences, School of Dentistry, University of Michigan, Ann Arbor 48109-0402, USA
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40
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Banas JA, Simon D, Williams LK, Ferretti JJ, Russell RR. Analysis of a primer-independent GTF-I from Streptococcus salivarius. FEMS Microbiol Lett 1994; 123:349-54. [PMID: 7988916 DOI: 10.1111/j.1574-6968.1994.tb07247.x] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/28/2023] Open
Abstract
A glucosyltransferase (GTF) gene, designated gtfL, from Streptococcus salivarius was cloned and expressed in Escherichia coli and its nucleotide sequence determined. The GTF-L enzyme catalysed the synthesis of water-insoluble glucan in a primer-independent manner. The nucleotide sequence and derived amino acid sequence of GTF-L were similar in size and domain structure to previously sequenced glucosyltransferases. However, a 464-bp region of high variability was identified which could be selectively amplified from strains of S. salivarius by the polymerase chain reaction and could therefore form the basis for species identification. No sequence-specific motifs related to the solubility and linkage of the glucan product or its need for a dextran primer could be ascertained.
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Affiliation(s)
- J A Banas
- Department of Microbiology, University of Oklahoma H.S.C., Oklahoma City 73190
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41
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Rudney JD, Larson CJ. Use of restriction fragment polymorphism analysis of rRNA genes to assign species to unknown clinical isolates of oral viridans streptococci. J Clin Microbiol 1994; 32:437-43. [PMID: 7512095 PMCID: PMC263050 DOI: 10.1128/jcm.32.2.437-443.1994] [Citation(s) in RCA: 23] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/25/2023] Open
Abstract
This study evaluated restriction fragment length polymorphisms of rRNA genes (ribotyping) for genotypic identification of 53 oral isolates classified as "Streptococcus sanguis" by colony morphology. Isolates were from 8-h buccal plaque on lower first permanent molars of 20 subjects. DNA was digested with AatII and hybridized with digoxygenin-labeled cDNA of Escherichia coli 16S and 23S rRNA. Strains were ribotyped again with AlwNI or PvuII on the basis of the presence or absence of a 2,290-bp AatII band. Band patterns were compared with reference ribotypes for Streptococcus gordonii, Streptococcus sanguis, Streptococcus crista, Streptococcus oralis, Streptococcus mitis, and Streptococcus parasanguis strains. Forty-eight isolates could be assigned to a species (22 S. sanguis, 14 S. oralis, 12 S. gordonii). Multiple species were seen in 14 subjects; multiple strains of the same species occurred in 11 subjects. Our findings suggest that ribotyping can be used for genotypic identification of S. sanguis, S. oralis, and S. gordonii isolates.
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Affiliation(s)
- J D Rudney
- Department of Oral Science, School of Dentistry, University of Minnesota, Minneapolis 55455
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42
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Baselga R, Albizu I, De La Cruz M, Del Cacho E, Barberan M, Amorena B. Phase variation of slime production in Staphylococcus aureus: implications in colonization and virulence. Infect Immun 1993; 61:4857-62. [PMID: 8406887 PMCID: PMC281244 DOI: 10.1128/iai.61.11.4857-4862.1993] [Citation(s) in RCA: 85] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/30/2023] Open
Abstract
Two methods commonly used for slime detection in coagulase-negative staphylococci (tube biofilm formation and colony morphology in Congo red agar) were used to study 144 ruminant mastitis Staphylococcus aureus strains. Slime production was detected in 21 strains. A majority of cells (85%) in slime-producing (SP) strains and a minority of cells (5%) in non-slime-producing (NSP) strains showed a condensed exopolysaccharide matrix (slime) surrounding the bacterial cell wall, as revealed by electron microscopy and immunofluorescence. In vivo slime production was also detected immunohistochemically after experimental infection of the mammary gland in sheep. Upon repeated subcultures in Congo red agar, NSP variants were obtained from four ovine and four bovine SP strains at a frequency ranging from 0.5 x 10(-4) to 10(-4). Because SP variants could not be obtained from NSP strains within this range or at a higher frequency, they were obtained by the tube biofilm formation (requiring repeated subculturing of NSP strains in tryptic soy broth containing 2% glucose for subsequent recovery of colonies adherent to the walls of the culture tubes). In experimental challenge, the SP variant showed a significantly higher colonization capacity than did the NSP variant of the same strain used (P < 0.001). However, the NSP variant had a higher virulence than did the SP variant (P < 0.001). These results may help to explain the different roles of S. aureus slime production cell types (SP and NSP) coexisting in disease.
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Affiliation(s)
- R Baselga
- CSIC Department of Animal Production, (SIA-DGA), Zaragoza, Spain
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43
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Wells VD, Munro CL, Sulavik MC, Clewell DB, Macrina FL. Infectivity of a glucan synthesis-defective mutant of Streptococcus gordonii (Challis) in a rat endocarditis model. FEMS Microbiol Lett 1993; 112:301-5. [PMID: 8224794 DOI: 10.1111/j.1574-6968.1993.tb06466.x] [Citation(s) in RCA: 23] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/29/2023] Open
Abstract
Streptococcus gordonii, a member of the human indigenous oral microflora, colonizes smooth tooth surfaces and contributes to dental plaque formation. Although it is not recognized as being a cariogenic pathogen, it may cause endocarditis following invasion of the bloodstream. Using allelic exchange mutagenesis, we have constructed a mutant of S. gordonii (Challis) which is defective in its single functional glucosyltransferase gene and, hence, is unable to synthesize glucan exopolymers from sucrose. When examined in a rat endocarditis model, the sucrose-grown mutant did not differ significantly from S. gordonii wild-type, suggesting that glucan polymers did not contribute to infectivity. This result was in striking contrast to that previously observed with a polymer-defective S. mutans mutant.
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Affiliation(s)
- V D Wells
- Department of Microbiology and Immunology, Virginia Commonwealth University, Richmond 23298-0678
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44
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Rudney JD, Larson CJ. Species identification of oral viridans streptococci by restriction fragment polymorphism analysis of rRNA genes. J Clin Microbiol 1993; 31:2467-73. [PMID: 7691875 PMCID: PMC265779 DOI: 10.1128/jcm.31.9.2467-2473.1993] [Citation(s) in RCA: 16] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/26/2023] Open
Abstract
Oral streptococci formerly classified as Streptococcus sanguis have been divided into six genetic groups. Methods to identify those species by genotype are needed. This study compared restriction fragment polymorphisms of rRNA genes (ribotypes) for seven S. gordonii, three S. sanguis, four S. oralis, three S. mitis, one S. crista, and seven S. parasanguis strains classified in previous DNA hybridization studies, as well as one clinical isolate. DNA was digested with HindIII, PvuII, HindIII and PvuII combined, EcoRI, BamHI, AatII, AlwNI, and DraII. DNA fragments were hybridized with a digoxigenin-labeled cDNA probe obtained by reverse transcription of Escherichia coli 16S and 23S rRNA. S. oralis, S. mitis, and S. parasanguis all showed an isolated 2,290-bp band in AatII ribotypes that was absent from S. gordonii, S. sanguis, and S. crista. The last three groups showed species-specific bands with AatII and also with PvuII. S. oralis could be distinguished from S. mitis and S. parasanguis in AlwNI and DraII ribotypes. S. mitis and S. parasanguis could not be distinguished, since they shared multiple bands in PvuII, AlwNI, and EcoRI patterns. The clinical isolate in the panel was very similar to S. sanguis by all enzymes used. Our findings suggest that ribotyping may be useful for genotypic identification of oral viridans streptococci. Initial digests of clinical isolates might be made with AatII, followed by PvuII or AlwNI. Isolates then could be identified by comparing ribotype patterns with those of reference strains. This approach could facilitate clinical studies of these newly defined species.
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Affiliation(s)
- J D Rudney
- Department of Oral Science, School of Dentistry, University of Minnesota, Minneapolis 55455
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45
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Vickerman MM, Jones GW. Adhesion of glucosyltransferase phase variants to Streptococcus gordonii bacterium-glucan substrata may involve lipoteichoic acid. Infect Immun 1992; 60:4301-8. [PMID: 1398940 PMCID: PMC257466 DOI: 10.1128/iai.60.10.4301-4308.1992] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/26/2022] Open
Abstract
Growing Streptococcus gordonii Spp+ phase variants, which have normal levels of glucosyltransferase (GTF) activity, use sucrose to promote their accumulation on surfaces by forming a cohesive bacterium-insoluble glucan polymer mass (BPM). Spp- phase variants, which have lower levels of GTF activity, do not form BPMs and do not remain in BPMs formed by Spp+ cells when grown in mixed cultures. To test the hypothesis that segregation of attached Spp+ and unattached Spp- cells was due to differences in adhesiveness, adhesion between washed, [3H]thymidine-labeled cells and preformed BPM substrata was measured. Unexpectedly, the results showed that cells of both phenotypes, as well as GTF-negative cells, attached equally well to preformed BPMs, indicating that attachment to BPMs was independent of cell surface GTF activity. Initial characterization of this binding interaction suggested that a protease-sensitive component on the washed cells may be binding to lipoteichoic acids sequestered in the BPM, since exogenous lipoteichoic acid inhibited adhesion. Surprisingly, the adhesion of both Spp+ and Spp- cells was markedly inhibited in the presence of sucrose, which also released lipoteichoic acid from the BPM. These in vitro findings suggest that, in vivo, sucrose and lipoteichoic acid may modify dental plaque development by enhancing or inhibiting the attachment of additional bacteria.
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Affiliation(s)
- M M Vickerman
- Department of Cariology and General Dentistry, School of Dentistry, University of Michigan, Ann Arbor 48109
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46
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Affiliation(s)
- D L Hasty
- Department of Anatomy, University of Tennessee, Memphis 38163
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47
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Sulavik MC, Tardif G, Clewell DB. Identification of a gene, rgg, which regulates expression of glucosyltransferase and influences the Spp phenotype of Streptococcus gordonii Challis. J Bacteriol 1992; 174:3577-86. [PMID: 1534326 PMCID: PMC206044 DOI: 10.1128/jb.174.11.3577-3586.1992] [Citation(s) in RCA: 83] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/27/2022] Open
Abstract
Streptococcus gordonii Challis was previously shown to give rise to phase variants expressing high (Spp+) or low (Spp-) levels of extracellular glucosyltransferase (GTF) activity. Here, shotgun cloning of an S. gordonii Spp+ chromosomal digest resulted in a chimeric plasmid (pAM5010) able to complement the Spp- phenotype. In addition, introduction of pAM5010 into an Spp+ strain resulted in a 10-fold increase in GTF expression. Deletion analysis of pAM5010 identified a 1.2-kb DNA segment which exhibited the same functional properties as pAM5010. Nucleotide sequence analysis of this region revealed a gene approximately 1 kb in size. The gene was designated rgg. Disruption of the chromosomal rgg gene open reading frame in an Spp+ strain resulted in strain DS512, which displayed an Spp(-)-like phenotype and had 3% of wild-type GTF activity. A plasmid containing the rgg gene was able to complement the DS512 phenotype and significantly increase GTF expression above wild-type levels. Sequence analysis and other data showed that the S. gordonii GTF determinant, designated gtfG, is located 66 bp downstream of the rgg gene. The sequence also revealed interesting inverted repeats which may play a role in the regulation of gtfG. We conclude that rgg positively regulates the expression of GTF and influences expression of the Spp phenotype.
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Affiliation(s)
- M C Sulavik
- Department of Microbiology and Immunology, School of Medicine, University of Michigan, Ann Arbor 48109-0402
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48
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Vickerman MM, Clewell DB, Jones GW. Glucosyltransferase phase variation in Streptococcus gordonii modifies adhesion to saliva-coated hydroxyapatite surfaces in a sucrose-independent manner. ORAL MICROBIOLOGY AND IMMUNOLOGY 1992; 7:118-20. [PMID: 1388259 DOI: 10.1111/j.1399-302x.1992.tb00521.x] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/26/2022]
Abstract
Phase variation of Streptococcus gordonii between high (Spp+) and low (Spp-) levels of glucosyltransferase (GTF) activity resulted in the greater adhesion of Spp- strains to saliva-coated hydroxyapatite (S-HA) in a washed-cell adhesion test. Specific GTF mutants did not show this response. Although washed Spp+ cells produced 5-fold or more glucan from sucrose than Spp- cells did under the conditions of the adhesion test, sucrose elevated the adhesion of both phenotypes to hydroxyapatite (HA) equally, but had no effect on adhesion to S-HA. This effect was not sucrose-specific, however, because equimolar amounts of other carbohydrates and NaCl elevated adhesion of both Spp types to levels similar to those seen with sucrose. Adhesion did not correlate with relative changes in cell hydrophobicity. These results suggest that, in addition to changes in GTF activity, other changes relevant to adhesion may occur during Spp phase variation.
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Affiliation(s)
- M M Vickerman
- School of Medicine, University of Michigan, Ann Arbor
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Vickerman MM, Clewell DB, Jones GW. Ecological implications of glucosyltransferase phase variation in Streptococcus gordonii. Appl Environ Microbiol 1991; 57:3648-51. [PMID: 1838470 PMCID: PMC184028 DOI: 10.1128/aem.57.12.3648-3651.1991] [Citation(s) in RCA: 19] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/29/2022] Open
Abstract
When sucrose is provided as a substrate for glucosyltransferase (GTF), Spp+ cells of the oral bacteria Streptococcus gordonii grow embedded in an insoluble glucan mass associated with surfaces. Spp- phase variants with lower GTF activity, which either arise from or are grown with Spp+ cells, segregate preferentially as unattached cells in the culture supernatants. Conversely, Spp+ revertants preferentially accumulate on surfaces. GTF phase variation, therefore, may facilitate the dispersion of S. gordonii cells throughout the oral cavity.
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Affiliation(s)
- M M Vickerman
- Department of Cariology and General Dentistry, School of Dentistry, Unviersity of Michigan, Ann Arbor 48109-0620
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Vickerman MM, Clewell DB, Jones GW. Sucrose-promoted accumulation of growing glucosyltransferase variants of Streptococcus gordonii on hydroxyapatite surfaces. Infect Immun 1991; 59:3523-30. [PMID: 1716611 PMCID: PMC258916 DOI: 10.1128/iai.59.10.3523-3530.1991] [Citation(s) in RCA: 33] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/28/2022] Open
Abstract
Streptococcus gordonii exhibits a phase variation involving expression of high (Spp+) or low (Spp-) glucosyltransferase activity. The related bacterial accumulation on hydroxyapatite (HA) and saliva-coated HA surfaces was examined and found to be significant. Spp+ cells growing anaerobically in a defined medium utilize about 30% of the glucose available from sucrose to make insoluble glucans. These glucans formed cohesive masses on HA beads, which contained 80 to 90% of the total bacteria. The bacterial polymer mass had a volume of about 40 microns3 and contained more than 5 x 10(10) viable cells per cm3. In the absence of sucrose, the beads were saturated by 1 x 10(8) to 2 x 10(8) Spp+ cells. Spp- bacteria, which make 30-fold less glucan than do Spp+ bacteria, did not accumulate on surfaces in numbers significantly above the saturation level of 1 x 10(8) to 2 x 10(8) cells in the presence or absence of sucrose. Insoluble glucan synthesized by Spp+ cells from sucrose also enabled these bacteria to accumulate on saliva-coated HA seven times more effectively than the Spp- cells and 10 times more effectively than the Spp+ cells grown in medium without sucrose.
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Affiliation(s)
- M M Vickerman
- Department of Microbiology, School of Medicine, University of Michigan, Ann Arbor 48109
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