scholarly journals Characterization of competence and biofilm development of a Streptococcus sanguinis endocarditis isolate

2011 ◽  
Vol 26 (2) ◽  
pp. 117-126 ◽  
Author(s):  
L. Zhu ◽  
Y. Zhang ◽  
J. Fan ◽  
M.C. Herzberg ◽  
J. Kreth
Keyword(s):  
Streptococcus Sanguinis ◽  
Biofilm Development

Influence of Seeding Conditions on Initial Biofilm Development during the Startup of Anaerobic Fluidized Bed Reactors

1989 ◽  
Vol 21 (4-5) ◽  
pp. 157-165 ◽  
Author(s):  
F. Ehlinger ◽  
J. M. Audic ◽  
G. M. Faup
Keyword(s):  
Fluidized Bed ◽  
Future Development ◽  
Protein Concentration ◽  
Specific Activity ◽  
Fluidized Bed Reactor ◽  
Fluidized Bed Reactors ◽  
Support Material ◽  
Biofilm Development ◽  
Initial Biofilm

The characterization of the biofilm of an anaerobic fluidized-bed reactor was completed under standard conditions. The distribution of the fixed protein concentration depended on the level in the reactor. The protein concentration reached 1520 µg.g−1 of support at the top of the reactor and only 1200 µg.g−1 at the bottom after 504 hours of operation but the specific activity of the biofilm was 33×10−4 µM acetate.h−1.mg−1 proteins at the bottom and only 26×10−4 µM.h−1.mg−1 at the top. The efficiency of a fluidized bed reactor and the composition of the biofilm changed with an increase of the pH from 7 to 8.5 during the seeding of the support material. Future development of the biofilm and the specific activity of the support were affected.

scholarly journals Toward Personalized Oral Diagnosis: Distinct Microbiome Clusters in Periodontitis Biofilms

2021 ◽  
Vol 11 ◽  
Author(s):  
Roland Wirth ◽  
Bernadett Pap ◽  
Gergely Maróti ◽  
Péter Vályi ◽  
Laura Komlósi ◽  
...  
Keyword(s):  
Amplicon Sequencing ◽  
Abundant Species ◽  
Periodontal Pathogen ◽  
Host Immune System ◽  
Periodontal Pathogens ◽  
Pocket Depth ◽  
Probing Pocket Depth ◽  
The Individual ◽  
Biofilm Development

Periodontitis is caused by pathogenic subgingival microbial biofilm development and dysbiotic interactions between host and hosted microbes. A thorough characterization of the subgingival biofilms by deep amplicon sequencing of 121 individual periodontitis pockets of nine patients and whole metagenomic analysis of the saliva microbial community of the same subjects were carried out. Two biofilm sampling methods yielded similar microbial compositions. Taxonomic mapping of all biofilms revealed three distinct microbial clusters. Two clinical diagnostic parameters, probing pocket depth (PPD) and clinical attachment level (CAL), correlated with the cluster mapping. The dysbiotic microbiomes were less diverse than the apparently healthy ones of the same subjects. The most abundant periodontal pathogens were also present in the saliva, although in different representations. The single abundant species Tannerella forsythia was found in the diseased pockets in about 16–17-fold in excess relative to the clinically healthy sulcus, making it suitable as an indicator of periodontitis biofilms. The discrete microbial communities indicate strong selection by the host immune system and allow the design of targeted antibiotic treatment selective against the main periodontal pathogen(s) in the individual patients.

Isolation and Characterization of a microRNA-size Secretable Small RNA in Streptococcus sanguinis

2016 ◽  
Vol 76 (1-2) ◽  
pp. 293-301 ◽  
Author(s):  
Ji-Woong Choi ◽  
Tae-Yub Kwon ◽  
Su-Hyung Hong ◽  
Heon-Jin Lee
Keyword(s):  
Small Rna ◽  
Streptococcus Sanguinis ◽  
Isolation And Characterization

scholarly journals Isolation and Characterization of an Autoinducer Synthase from Acinetobacter baumannii

2008 ◽  
Vol 190 (9) ◽  
pp. 3386-3392 ◽  
Author(s):  
Chen Niu ◽  
Katy M. Clemmer ◽  
Robert A. Bonomo ◽  
Philip N. Rather
Keyword(s):  
Acinetobacter Baumannii ◽  
Homoserine Lactone ◽  
Transcriptional Level ◽  
Human Pathogen ◽  
Isolation And Characterization ◽  
Opportunistic Human Pathogen ◽  
Biofilm Development ◽  
Culture Supernatants ◽  
Ethyl Acetate Extracts

ABSTRACT The opportunistic human pathogen Acinetobacter baumannii strain M2 was found to produce distinct acyl-homoserine lactone (AHL) signals based on the use of an Agrobacterium tumefaciens traG-lacZ biosensor. An A. baumannii gene, designated abaI, was cloned and directed AHL production in recombinant Escherichia coli. The AbaI protein was similar to members of the LuxI family of autoinducer synthases and was predicted to be the only autoinducer synthase encoded by A. baumannii. The primary AHL signal directed by AbaI was identified by mass spectrometry as being N-(3-hydroxydodecanoyl)-l-HSL (3-hydroxy-C12-HSL). Minor amounts of at least five additional AHLs were also identified. The expression of abaI at the transcriptional level was activated by ethyl acetate extracts of culture supernatants or by synthetic 3-hydroxy-C12-HSL. An abaI::Km mutant failed to produce any detectable AHL signals and was impaired in biofilm development.

scholarly journals Physiological and molecular characterization of genetic competence in Streptococcus sanguinis

2011 ◽  
Vol 26 (3) ◽  
pp. 228-228
Author(s):  
A.M. Rodriguez ◽  
J.E. Callahan ◽  
P. Fawcett ◽  
X. Ge ◽  
P. Xu ◽  
...  
Keyword(s):  
Molecular Characterization ◽  
Genetic Competence ◽  
Streptococcus Sanguinis

scholarly journals Murein Hydrolase LytF of Streptococcus sanguinis and the Ecological Consequences of Competence Development

2017 ◽  
Vol 83 (24) ◽  
Author(s):  
Nyssa Cullin ◽  
Sylvio Redanz ◽  
Kirsten J. Lampi ◽  
Justin Merritt ◽  
Jens Kreth
Keyword(s):  
Dental Caries ◽  
Oral Cavity ◽  
Cell Morphology ◽  
Biofilm Formation ◽  
Oral Bacteria ◽  
Tooth Surface ◽  
Content Type ◽  
Streptococcus Sanguinis ◽  
Murein Hydrolase ◽  
Biofilm Development

ABSTRACT The overall health of the oral cavity is dependent on proper homeostasis between health-associated bacterial colonizers and bacteria known to promote dental caries. Streptococcus sanguinis is a health-associated commensal organism, a known early colonizer of the acquired tooth pellicle, and is naturally competent. We have shown that LytF, a competence-controlled murein hydrolase, is capable of inducing the release of extracellular DNA (eDNA) from oral bacteria. Precipitated LytF and purified LytF were used as treatments against planktonic cultures and biofilms. Larger amounts of eDNA were released from cultures treated with protein samples containing LytF. Additionally, LytF could affect biofilm formation and cellular morphology. Biofilm formation was significantly decreased in the lytF-complemented strain, in which increased amounts of LytF are present. The same strain also exhibited cell morphology defects in both planktonic cultures and biofilms. Furthermore, the LytF cell morphology phenotype was reproducible in wild-type cells using purified LytF protein. In sum, our findings demonstrate that LytF can induce the release of eDNA from oral bacteria, and they suggest that, without proper regulation of LytF, cells display morphological abnormalities that contribute to biofilm malformation. In the context of the oral biofilm, LytF may play important roles as part of the competence and biofilm development programs, as well as increasing the availability of eDNA. IMPORTANCE Streptococcus sanguinis, a commensal organism in the oral cavity and one of the pioneer colonizers of the tooth surface, is associated with the overall health of the oral environment. Our laboratory showed previously that, under aerobic conditions, S. sanguinis can produce H2O2 to inhibit the growth of bacterial species that promote dental caries. This production of H2O2 by S. sanguinis also induces the release of eDNA, which is essential for proper biofilm formation. Under anaerobic conditions, S. sanguinis does not produce H2O2 but DNA is still released. Determining how S. sanguinis releases DNA is thus essential to understand biofilm formation in the oral cavity.

scholarly journals Molecular Characterization of Subject-Specific Oral Microflora during Initial Colonization of Enamel

2006 ◽  
Vol 72 (4) ◽  
pp. 2837-2848 ◽  
Author(s):  
Patricia I. Diaz ◽  
Natalia I. Chalmers ◽  
Alexander H. Rickard ◽  
Colin Kong ◽  
Craig L. Milburn ◽  
...  
Keyword(s):  
Community Composition ◽  
Bacterial Species ◽  
Microbial Community Composition ◽  
Microbial Colonization ◽  
Rrna Gene ◽  
Dependent Manner ◽  
Clone Libraries ◽  
Tooth Surfaces ◽  
Biofilm Development

ABSTRACT The initial microbial colonization of tooth surfaces is a repeatable and selective process, with certain bacterial species predominating in the nascent biofilm. Characterization of the initial microflora is the first step in understanding interactions among community members that shape ensuing biofilm development. Using molecular methods and a retrievable enamel chip model, we characterized the microbial diversity of early dental biofilms in three subjects. A total of 531 16S rRNA gene sequences were analyzed, and 97 distinct phylotypes were identified. Microbial community composition was shown to be statistically different among subjects. In all subjects, however, 4-h and 8-h communities were dominated by Streptococcus spp. belonging to the Streptococcus oralis/Streptococcus mitis group. Other frequently observed genera (comprising at least 5% of clone sequences in at least one of the six clone libraries) were Actinomyces, Gemella, Granulicatella, Neisseria, Prevotella, Rothia, and Veillonella. Fluorescence in situ hybridization (FISH) confirmed that the proportion of Streptococcus sp. sequences in the clone libraries coincided with the proportion of streptococcus probe-positive organisms on the chip. FISH also revealed that, in the undisturbed plaque, not only Streptococcus spp. but also the rarer Prevotella spp. were usually seen in small multigeneric clusters of cells. This study shows that the initial dental plaque community of each subject is unique in terms of diversity and composition. Repetitive and distinctive community composition within subjects suggests that the spatiotemporal interactions and ecological shifts that accompany biofilm maturation also occur in a subject-dependent manner.

scholarly journals Physiological and molecular characterization of genetic competence in Streptococcus sanguinis

2011 ◽  
Vol 26 (2) ◽  
pp. 99-116 ◽  
Author(s):  
A.M. Rodriguez ◽  
J.E. Callahan ◽  
P. Fawcett ◽  
X. Ge ◽  
P. Xu ◽  
...  
Keyword(s):  
Molecular Characterization ◽  
Genetic Competence ◽  
Streptococcus Sanguinis

scholarly journals Characterization of Bacterial Etiologic Agents of Biofilm Formation in Medical Devices in Critical Care Setup

2012 ◽  
Vol 2012 ◽  
pp. 1-6 ◽  
Author(s):  
Sangita Revdiwala ◽  
Bhaumesh M. Rajdev ◽  
Summaiya Mulla
Keyword(s):  
Critical Care ◽  
Medical Devices ◽  
Biofilm Formation ◽  
Medical Implants ◽  
Bacterial Isolates ◽  
Critical Care Units ◽  
Etiologic Agents ◽  
Bacterial Drug Resistance ◽  
Biofilm Development

Background. Biofilms contaminate catheters, ventilators, and medical implants; they act as a source of disease for humans, animals, and plants.Aim. Critical care units of any healthcare institute follow various interventional strategies with use of medical devices for the management of critical cases. Bacteria contaminate medical devices and form biofilms.Material and Methods. The study was carried out on 100 positive bacteriological cultures of medical devices which were inserted in hospitalized patients. The bacterial isolates were processed as per microtitre plate. All the isolates were subjected to antibiotic susceptibility testing by VITEK 2 compact automated systems.Results. Out of the total 100 bacterial isolates tested, 88 of them were biofilm formers. A 16–20-hour incubation period was found to be optimum for biofilm development. 85% isolates were multidrug resistants and different mechanisms of bacterial drug resistance like ESBL, carbapenemase, and MRSA were found among isolates.Conclusion. Availability of nutrition in the form of glucose enhances the biofilm formation by bacteria. Time and availability of glucose are important factors for assessment of biofilm progress. It is an alarm for those who are associated with invasive procedures and indwelling medical devices especially in patients with low immunity.

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