Differentiation of mutans streptococci by intact cell matrix‐assisted laser desorption/ionization time‐of‐flight mass spectrometry

Rupf, Stefan; Breitung, K.; Schellenberger, Wolfgang; Merte, K; Kneist, S; Eschrich, Klaus

doi:10.1111/j.1399-302x.2005.00223.x

Cited by 50 publications

(42 citation statements)

References 34 publications

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“…Furthermore, it has been reported that S. criceti strains AHT and E49 should be reclassified as S. ratti strains (27). Although some strains of S. criceti used by researchers have been reclassified, it is probable that our reference strain, S. criceti E49, is S. criceti (serotype a) because of the identical nucleotide sequence of the dex gene to that of S. criceti ATCC19642 (type strain).…”

Section: Discussionmentioning

confidence: 99%

Identification and Characterization of a Dextranase Gene of Streptococcus criceti

Tamura

Yamada

Kato

2007

Microbiology and Immunology

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The dextranase gene, dex, was identified in Streptococcus criceti strain E49 by degenerate PCR and sequenced completely by the gene‐walking method. A sequence of 3,960 nucleotides was determined. The dex gene encodes a 1,200‐amino acid protein, which has a calculated molecular mass of 128,129.91 and pI of 4.15 and is predicted to be a cell‐surface protein. The deduced amino acid sequence of dex showed homology to S. downei dextranase (63.9% identity). Phylogenetic analysis revealed the similarity of the deduced amino acid sequence of dextranases in S. criceti, S. sobrinus, and S. downei. A recombinant form of the protein with six histidine residues tagged in the C‐terminus was partially purified and showed dextranase activity on blue‐dextran sodium dodecyl sulfate‐polyacrylamide gel electrophoresis (BD‐SDS‐PAGE) followed by renaturation. We also detected dextranase activity in S. criceti cell extracts and culture supernatant by renatured BD‐SDS‐PAGE, whereas no dextranase activity of the cells was observed on blue‐dextran brain heart infusion (BD‐BHI) agar plates. Furthermore, PCR‐based mutations of dextranase indicated that a deletion mutant of the C‐terminal region could hydrolyze blue dextrans and that the D453E mutation, W793L mutation, and double mutations (W793L and deletion of the C‐terminal region) resulted in a loss of dextranase activity. These findings suggest that Asp‐453 and Trp‐793 residues of S. criceti dextranase are critical to the enzyme's activity.

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Section: Discussionmentioning

confidence: 99%

Identification and Characterization of a Dextranase Gene of Streptococcus criceti

Tamura

Yamada

Kato

2007

Microbiology and Immunology

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Section: Resultsmentioning

confidence: 99%

“…Special emphasis was laid on the correct species identification of the streptococci. As it is known that conventional biochemical tests may fail to discern certain species of viridans streptococci, the recently established MALDI-TOF-MS methodology (Smole et al, 2002;Rupf et al, 2005;Friedrichs et al, 2007) was used and adjusted for this study.The results indicated that, among the 11 species cultured from patients and healthy individuals, only one species -S. sanguinis -showed significant differences in colonization rates for the two groups, and was associated with health rather than disease.It has been demonstrated previously that S. sanguinis is a beneficial bacterium in the prevention of dental caries. The antagonism with S. mutans has been known for many years.…”

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confidence: 99%

Periodontitis is associated with a loss of colonization by Streptococcus sanguinis

Stingu

Eschrich

Rodloff

et al. 2008

Journal of Medical Microbiology

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The aim of this study was to estimate differences in the prevalence of oral streptococcal species in the subgingival biofilm of patients with aggressive periodontitis and of healthy controls. Thirty-three patients with clinical and radiological proof of aggressive periodontitis and 20 healthy subjects were enrolled in this study. Clinical indices were recorded in a six-point measurement per tooth. Samples of the subgingival biofilm were taken with paper points from four teeth of each individual. Alpha-and non-haemolytic, small and catalase-negative colonies were biochemically identified using a rapid ID 32 STREP system and matrix-assisted laser desorption/ionization time-of-flight mass spectrometry. A total of 118 strains of oral streptococci (11 species) were identified and Streptococcus sanguinis was found significantly more often in healthy subjects (P50.001). Conversely, the absence of S. sanguinis was associated with high values of clinical indices (P50.001-0.002). Aggressive periodontitis seems to be associated with a loss of colonization of S. sanguinis. Whether or not S. sanguinis offers protection against aggressive periodontitis needs to be determined. Otherwise, there were no significant differences in the distribution of oral streptococcal species in patients and healthy subjects. INTRODUCTIONHealthy gingivae are associated with a simple supragingival biofilm composition: a few (1-20) layers of oral streptococci, Gram-positive rods and very few Gram-negative cocci. These bacteria are early colonizers that are able to survive in an aerated environment. In contrast, clinical gingivitis is associated with the development of a more organized dental plaque of 100-300 layers, with anaerobic Gram-negative rods and filaments being predominant. The species involved in biofilm formation may vary depending on local environmental characteristics, but the colonization pattern is always the same (Marsh & Bradshaw, 1999;Marsh, 2004).Bacterial communities from dental biofilms tend to be grouped in clusters (complexes) according to nutritional and atmospheric requirements. The initiation and progression of periodontitis is thought to be caused by several species belonging to 'red' and 'orange' complexes (Porphyromonas gingivalis, Tannerella forsythia and Treponema denticola, and Prevotella intermedia and Fusobacterium nucleatum, respectively) . However, according to the 'ecological plaque hypothesis ' (Marsh, 1991), the lack of so-called 'protective bacteria' is also thought to play an important role. These are microbial species that can occupy a niche that could shelter pathogenic organisms or that can inhibit some pathogens through metabolic antagonism or by directly inactivating them (Quirynen et al., 2001). Some of the members of the 'yellow' complex of oral streptococci are candidates for this position. Plaque samples from healthy gingival sulci normally contain a large number of oral streptococci (Theilade et al., 1966). Socransky et al. (1998) previously showed that yellow complexes, as a total, were associate...

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“…A publication in 2000 suggested that mass spectra of spore cells of the Bacillus cereus group allow differentiation from other Bacillus species (17), streptococci of the mutans group were successfully differentiated by MALDI-TOF MS in 2005 (16), and viridians streptococci have been successfully discriminated by MALDI-TOF MS in 2007 (9). By now, dedicated mass spectrometry systems are established for routine species identification in many laboratories that achieve discrimination of even closely related species by the comparison of spectrum fingerprints acquired within minutes from tiny amounts of colony material to exhaustive reference databases.…”

Section: Discussionmentioning

confidence: 99%

Differentiation of Streptococcus pneumoniae from Nonpneumococcal Streptococci of the Streptococcus mitis Group by Matrix-Assisted Laser Desorption Ionization–Time of Flight Mass Spectrometry

et al. 2012

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The differentiation of species within the Streptococcus mitis group has posed a problem in the routine diagnostic microbiology laboratory for some time. It also constitutes a major weakness of recently introduced matrix-assisted laser desorption ionization–time of flight mass spectrometry (MALDI-TOF MS) fingerprinting systems. As the phylogenetic resolution of the spectral similarity measures employed by these systems is insufficient to reliably distinguish between the most closely related members of the group, the major pathogen Streptococcus pneumoniae is frequently misidentified. In this study, a comparative analysis of MALDI-TOF spectra of several species from the S. mitis group has been performed in order to identify single peaks that could be used to improve mass spectrometry-based identification of the respective species. A characteristic peak profile could be identified that unambiguously distinguished the 14 S. pneumoniae isolates studied from 33 nonpneumococcal isolates of the S. mitis group. In addition, specific peak combinations could be assigned to other members of the group. The findings of this study suggest that it is possible to distinguish different species of the S. mitis group by close analysis of their mass peak profiles.

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Differentiation of mutans streptococci by intact cell matrix‐assisted laser desorption/ionization time‐of‐flight mass spectrometry

Cited by 50 publications

References 34 publications

Identification and Characterization of a Dextranase Gene of Streptococcus criceti

Identification and Characterization of a Dextranase Gene of Streptococcus criceti

Periodontitis is associated with a loss of colonization by Streptococcus sanguinis

Differentiation of Streptococcus pneumoniae from Nonpneumococcal Streptococci of the Streptococcus mitis Group by Matrix-Assisted Laser Desorption Ionization–Time of Flight Mass Spectrometry

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