Molecular characterization of Streptococcus mutans gtfB gene isolated from families

OBJECTIVE: Caries is a multifactorial infectious disease and the main etiological agent is the bacteria Streptococcus mutans due to its virulence factors, which enable the adherence to dental enamel and favours the formation of dental biofilm through the production of extracellular polysaccharides. The transmission of S. mutans can occur between people, often within families. The present study aimed to evaluate the intrafamily genetic pattern of S. mutans through partial sequencing of the gene that encodes the glucosyltransferase β (gtfB) enzyme.METHODS: We previously analyzed saliva samples from 40 individuals from nine families, and it was obtained 64 isolates biochemically characterized as S. mutans. The isolates were evaluated by random amplification of polymorphic DNA (RAPD). Those with greater similarity were characterized by partial sequence 16S rRNA gene and the gtfB gene sequencing.RESULTS: It was observed genetic similarity among strains isolated from individuals with caries activity; while isolates from individual without caries showed that they are genetically distinct, suggesting a different virulence pattern.CONCLUSION: The present results demonstrated that partial sequencing of the gtfB gene showed to be a potential marker to investigate genetic pattern and virulence of S. mutans, deserving further investigation in order to identify families at risk of caries.

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Fluoride Binding to Streptococcus mutans Pellets Rich in Extracellular Polysaccharides

Caries Research ◽

10.1159/000515115 ◽

2021 ◽

pp. 1-4

Author(s):

Leonardo Libardi Pagotto ◽

Manuela da Silva Spinola ◽

Diego Figueiredo Nóbrega ◽

Jaime Aparecido Cury ◽

Livia Maria Andaló Tenuta

Keyword(s):

Streptococcus Mutans ◽

Extracellular Polysaccharides ◽

Dental Biofilm

Extracellular polysaccharides (EPS), mainly the insoluble ones, increase the cariogenicity of dental biofilm, but whether they interfere with the binding and retention of fluoride is unknown. EPS-rich (EPS+) and EPS-poor (EPS–) pellets of <i>Streptococcus mutans</i> were formed and treated with increasing fluoride concentrations (0, 0.1, 1, or 10 mM). A concentration-dependent fluoride binding was observed in both EPS– and EPS+ pellets, but the presence of EPS did not affect the retention of fluoride in the pellets. In conclusion, the data suggest that a matrix of dental biofilm rich in EPS does not affect fluoride retention in the biofilm.

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Characterization of Hafnia alvei by biochemical tests, random amplified polymorphic DNA PCR, and partial sequencing of 16S rRNA gene.

Journal of Clinical Microbiology ◽

10.1128/jcm.33.9.2372-2376.1995 ◽

1995 ◽

Vol 33 (9) ◽

pp. 2372-2376 ◽

Cited By ~ 31

Author(s):

J Ridell ◽

A Siitonen ◽

L Paulin ◽

O Lindroos ◽

H Korkeala ◽

...

Keyword(s):

16S Rrna ◽

16S Rrna Gene ◽

Random Amplified Polymorphic Dna ◽

Rrna Gene ◽

Biochemical Tests ◽

Hafnia Alvei ◽

Partial Sequencing ◽

Dna Pcr

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Fluoride Penetration and Clearance Are Higher in Exopolysaccharide-Containing Bacterial Pellets

Caries Research ◽

10.1159/000488596 ◽

2018 ◽

Vol 53 (1) ◽

pp. 16-23

Author(s):

Manuela S. Spinola ◽

Diego Figueiredo Nóbrega ◽

Altair Antoninha Del Bel Cury ◽

Antonio Pedro Ricomini Filho ◽

Jaime Aparecido Cury ◽

...

Keyword(s):

Streptococcus Mutans ◽

Extracellular Polysaccharides ◽

Dental Biofilm

Extracellular polysaccharides (EPS) could increase the penetration of fluoride through dental biofilm, reducing its cariogenicity. We measured the concentration of fluoride in EPS-containing (EPS+) or not-containing (EPS–) Streptococcus mutans bacterial pellets resembling test biofilms, before and up to 60 min after a 0.05% NaF rinse in situ. Fluoride penetration and clearance were higher in EPS+ bacterial pellets. The data suggest that EPS enhances fluoride penetration, but also accelerates fluoride clearance from dental biofilms.

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Identification and Characterization of Leuconostoc fallax Strains Isolated from an Industrial Sauerkraut Fermentation

Applied and Environmental Microbiology ◽

10.1128/aem.68.6.2877-2884.2002 ◽

2002 ◽

Vol 68 (6) ◽

pp. 2877-2884 ◽

Cited By ~ 52

Author(s):

Rodolphe Barrangou ◽

Sung-Sik Yoon ◽

Frederick Breidt, ◽

Henry P. Fleming ◽

Todd R. Klaenhammer

Keyword(s):

Lactic Acid ◽

Rrna Gene ◽

Bacterial Strains ◽

Variable Regions ◽

Random Amplification ◽

End Products ◽

Identification And Characterization ◽

The 16S Rrna Gene ◽

Endonuclease Digestion

ABSTRACT Lactic acid bacterial strains were isolated from brines sampled after 7 days of an industrial sauerkraut fermentation, and six strains were selected on the basis of susceptibility to bacteriophages. Bacterial growth in cabbage juice was monitored, and the fermentation end products were identified, quantified, and compared to those of Leuconostoc mesenteroides. Identification by biochemical fingerprinting, endonuclease digestion of the 16S-23S intergenic transcribed spacer region, and sequencing of variable regions V1 and V2 of the 16S rRNA gene indicated that the six selected sauerkraut isolates were Leuconostoc fallax strains. Random amplification of polymorphic DNA fingerprints indicated that the strains were distinct from one another. The growth and fermentation patterns of the L. fallax isolates were highly similar to those of L. mesenteroides. The final pH of cabbage juice fermentation was 3.6, and the main fermentation end products were lactic acid, acetic acid, and mannitol for both species. However, none of the L. fallax strains exhibited the malolactic reaction, which is characteristic of most L. mesenteroides strains. These results indicated that in addition to L. mesenteroides, a variety of L. fallax strains may be present in the heterofermentative stage of sauerkraut fermentation. The microbial ecology of sauerkraut fermentation appears to be more complex than previously indicated, and the prevalence and roles of L. fallax require further investigation.

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Molecular characterization of a ceftriaxone-resistant Neisseria gonorrhoeae strain found in Switzerland: a case report

Annals of Clinical Microbiology and Antimicrobials ◽

10.1186/s12941-021-00456-5 ◽

2021 ◽

Vol 20 (1) ◽

Author(s):

Konrad Egli ◽

Anna Roditscheff ◽

Ursula Flückiger ◽

Martin Risch ◽

Lorenz Risch ◽

...

Keyword(s):

Neisseria Gonorrhoeae ◽

23S Rrna ◽

Rrna Gene ◽

Limited Information ◽

Specific Pcr ◽

Appropriate Treatment ◽

23S Rrna Gene ◽

Allele Type ◽

Ciprofloxacin Resistance

Abstract Background The resistance of Neisseria gonorrhoeae to ceftriaxone is unusual in Switzerland. The underlying genotype responsible for resistance is suspected to be novel. Generally, resistance in Neisseria gonorrhoeae (Ng) involves a comprehensive set of genes with many different mutations leading to resistance to different β-lactams and fluoroquinolones. Case presentation A patient had a positive result from specific PCR for Ng. We routinely culture all clinical specimens with a positive NG-PCR. In this particular case, we isolated a strain with resistance to ceftriaxone in Switzerland. A total of seven different genes (penA, ponA, porinB, mtr, gyrA, parC, 23S rRNA gene) in this strain were partially sequenced for comparison with phenotypic susceptibility testing. Interestingly, two different mutations in the porinB gene were observed, and data on this gene are limited. Information on the identified allele type of the penA gene is very limited as well. Three different mutations of parC and gyrA that correlate with ciprofloxacin resistance were found. The combination of ceftriaxone and ciprofloxacin resistance makes an appropriate treatment difficult to obtain due to multidrug resistance. Conclusion The combined results for all genes show the appearance of new mutations in central Europe either due to worldwide spread or the emergence of new genetic combinations of mutations.

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Characterization of symbiotic and associated bacteria from entomopathogenic nematode Heterorhabditis sp. (nematode: Heterorhabditidae) isolated from India

Egyptian Journal of Biological Pest Control ◽

10.1186/s41938-020-00343-9 ◽

2020 ◽

Vol 30 (1) ◽

Author(s):

Rashid Pervez ◽

Showkat Ahmad Lone ◽

Sasmita Pattnaik

Keyword(s):

Insect Pests ◽

Entomopathogenic Nematode ◽

Alcaligenes Faecalis ◽

Symbiotic Bacteria ◽

Rrna Gene ◽

Main Body ◽

Associated Bacteria ◽

Molecular Approaches

Abstract Background Entomopathogenic nematodes (EPNs) harboring symbiotic bacteria are one of the safest alternatives to the chemical insecticides for the control of various insect pests. Infective juveniles of EPNs locate a target insect, enter through the openings, and reach the hemocoel, where they release the symbiotic bacteria and the target gets killed by the virulence factors of the bacteria. Photorhabdus with Heterorhabditis spp. are well documented; little is known about the associated bacteria. Main body In this study, we explored the presence of symbiotic and associated bacteria from Heterorhabditis sp. (IISR-EPN 09) and characterized by phenotypic, biochemical, and molecular approaches. Six bacterial isolates, belonging to four different genera, were recovered and identified as follows: Photorhabdus luminescens, one each strain of Providencia vermicola, Pseudomonas entomophila, Alcaligenes aquatilis, and two strains of Alcaligenes faecalis based on the phenotypic, biochemical criteria and the sequencing of 16S rRNA gene. Conclusion P. luminescens is symbiotically associated with Heterorhabditis sp. (IISR-EPN 09), whereas P. vermicola, P. entomophila, A. aquatilis, and A. faecalis are the associated bacteria. Further studies are needed to determine the exact role of the bacterial associates with the Heterorhabditis sp.

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Molecular characterization of the bacterial communities present in sheep's milk and cheese produced in South Brazilian Region via 16S rRNA gene metabarcoding sequencing

LWT ◽

10.1016/j.lwt.2021.111579 ◽

2021 ◽

Vol 147 ◽

pp. 111579

Author(s):

Creciana M. Endres ◽

Ícaro Maia S. Castro ◽

Laura D. Trevisol ◽

Juliana M. Severo ◽

Michele B. Mann ◽

...

Keyword(s):

16S Rrna ◽

16S Rrna Gene ◽

Molecular Characterization ◽

Bacterial Communities ◽

Rrna Gene

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Nanopore-Sequencing Characterization of the Gut Microbiota of Melolontha melolontha Larvae: Contribution to Protection against Entomopathogenic Nematodes?

Pathogens ◽

10.3390/pathogens10040396 ◽

2021 ◽

Vol 10 (4) ◽

pp. 396

Author(s):

Ewa Sajnaga ◽

Marcin Skowronek ◽

Agnieszka Kalwasińska ◽

Waldemar Kazimierczak ◽

Karolina Ferenc ◽

...

Keyword(s):

Gut Microbiota ◽

Entomopathogenic Nematodes ◽

Bacterial Species ◽

Antagonistic Activity ◽

Rrna Gene ◽

Nanopore Sequencing ◽

Bacterial Phyla ◽

Melolontha Melolontha

This study focused on the potential relationships between midgut microbiota of the common cockchafer Melolontha melolontha larvae and their resistance to entomopathogenic nematodes (EPN) infection. We investigated the bacterial community associated with control and unsusceptible EPN-exposed insects through nanopore sequencing of the 16S rRNA gene. Firmicutes, Proteobacteria, Actinobacteria, and Bacteroidetes were the most abundant bacterial phyla within the complex and variable midgut microbiota of the wild M. melolontha larvae. The core microbiota was found to include 82 genera, which accounted for 3.4% of the total number of identified genera. The EPN-resistant larvae differed significantly from the control ones in the abundance of many genera belonging to the Actinomycetales, Rhizobiales, and Clostridiales orders. Additionally, the analysis of the microbiome networks revealed different sets of keystone midgut bacterial genera between these two groups of insects, indicating differences in the mutual interactions between bacteria. Finally, we detected Xenorhabdus and Photorhabdus as gut residents and various bacterial species exhibiting antagonistic activity against these entomopathogens. This study paves the way to further research aimed at unravelling the role of the host gut microbiota on the output of EPN infection, which may contribute to enhancement of the efficiency of nematodes used in eco-friendly pest management.

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Molecular Characterization of Ciliate Diversity in Stream Biofilms

Applied and Environmental Microbiology ◽

10.1128/aem.01438-07 ◽

2008 ◽

Vol 74 (6) ◽

pp. 1740-1747 ◽

Cited By ~ 52

Author(s):

Andrew Dopheide ◽

Gavin Lear ◽

Rebecca Stott ◽

Gillian Lewis

Keyword(s):

18S Rrna ◽

Pcr Primers ◽

18S Rrna Gene ◽

Sequence Diversity ◽

Rrna Genes ◽

Rrna Gene ◽

Sequencing Analysis ◽

Specific Pcr ◽

Stream Biofilms

ABSTRACT Free-living protozoa are thought to be of fundamental importance in aquatic ecosystems, but there is limited understanding of their diversity and ecological role, particularly in surface-associated communities such as biofilms. Existing eukaryote-specific PCR primers were used to survey 18S rRNA gene sequence diversity in stream biofilms but poorly revealed protozoan diversity, demonstrating a need for protozoan-targeted primers. Group-specific PCR primers targeting 18S rRNA genes of the protozoan phylum Ciliophora were therefore designed and tested using DNA extracted from cultured protozoan isolates. The two most reliable primer combinations were applied to stream biofilm DNA, followed by cloning and sequencing analysis. Of 44 clones derived from primer set 384F/1147R, 86% were of probable ciliate origin, as were 25% of 44 clones detected by primer set 121F/1147R. A further 29% of 121F/1147R-detected clones matched sequences from the closely related phylum Apicomplexa. The highly ciliate-specific primer set 384F/1147R was subsequently used in PCRs on biofilm DNA from four streams exhibiting different levels of human impact, revealing differences in ciliate sequence diversity in samples from each site. Of a total of 240 clones, 73% were of probable ciliate origin; 54 different putative ciliate sequences were detected from throughout seven taxonomic ciliate classes. Sequences from Oligohymenophorea were most commonly detected in all samples, followed by either Spirotrichea or Phyllopharyngea. Restriction fragment length polymorphism profile-based analysis of clones suggested a potentially higher level of diversity than did sequencing. Nevertheless, newly designed PCR primers 384F/1147R were considered to provide an effective molecular basis for characterization of ciliate diversity in stream biofilms.

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