scholarly journals Probing of Microbial Biofilm Communities for Coadhesion Partners

2014 ◽  
Vol 80 (21) ◽  
pp. 6583-6590 ◽  
Author(s):  
Stefan Ruhl ◽  
Andreas Eidt ◽  
Holger Melzl ◽  
Udo Reischl ◽  
John O. Cisar
Keyword(s):  
Dental Plaque ◽  
Solid Phase ◽  
Screening Method ◽  
Bacterial Strains ◽  
Mixed Species ◽  
Simple Method ◽  
Content Type ◽  
Glycan Receptors ◽  
Fimbrial Adhesin

ABSTRACTInvestigations of interbacterial adhesion in dental plaque development are currently limited by the lack of a convenient assay to screen the multitude of species present in oral biofilms. To overcome this limitation, we developed a solid-phase fluorescence-based screening method to detect and identify coadhesive partner organisms in mixed-species biofilms. The applicability of this method was demonstrated using coaggregating strains of type 2 fimbrial adhesin-bearing actinomyces and receptor polysaccharide (RPS)-bearing streptococci. Specific adhesin/receptor-mediated coadhesion was detected by overlaying bacterial strains immobilized to a nitrocellulose membrane with a suspended, fluorescein-labeled bacterial partner strain. Coadhesion was comparable regardless of which cell type was labeled and which was immobilized. Formaldehyde treatment of bacteria, either in suspension or immobilized on nitrocellulose, abolished actinomyces type 2 fimbrial adhesin but not streptococcal RPS function, thereby providing a simple method for assigning complementary adhesins and glycan receptors to members of a coadhering pair. The method's broader applicability was shown by overlaying colony lifts of dental plaque biofilm cultures with fluorescein-labeled strains of type 2 fimbriatedActinomyces naeslundiior RPS-bearingStreptococcus oralis. Prominent coadhesion partners included not only streptococci and actinomyces, as expected, but also other bacteria not identified in previous coaggregation studies, such as adhesin- or receptor-bearing strains ofNeisseria pharyngitis,Rothia dentocariosa, andKingella oralis. The ability to comprehensively screen complex microbial communities for coadhesion partners of specific microorganisms opens a new approach in studies of dental plaque and other mixed-species biofilms.

scholarly journals Coaggregation-Mediated Interactions of Streptococci and Actinomyces Detected in Initial Human Dental Plaque

2003 ◽  
Vol 185 (11) ◽  
pp. 3400-3409 ◽  
Author(s):  
Robert J. Palmer, ◽  
Sharon M. Gordon ◽  
John O. Cisar ◽  
Paul E. Kolenbrander
Keyword(s):  
Dental Plaque ◽  
Single Cells ◽  
Spatial Arrangement ◽  
Oral Bacteria ◽  
Tooth Surface ◽  
Mixed Species ◽  
Bacterial Surface ◽  
Direct Demonstration

ABSTRACT Streptococci and actinomyces that initiate colonization of the tooth surface frequently coaggregate with each other as well as with other oral bacteria. These observations have led to the hypothesis that interbacterial adhesion influences spatiotemporal development of plaque. To assess the role of such interactions in oral biofilm formation in vivo, antibodies directed against bacterial surface components that mediate coaggregation interactions were used as direct immunofluorescent probes in conjunction with laser confocal microscopy to determine the distribution and spatial arrangement of bacteria within intact human plaque formed on retrievable enamel chips. In intrageneric coaggregation, streptococci such as Streptococcus gordonii DL1 recognize receptor polysaccharides (RPS) borne on other streptococci such as Streptococcus oralis 34. To define potentially interactive subsets of streptococci in the developing plaque, an antibody against RPS (anti-RPS) was used together with an antibody against S. gordonii DL1 (anti-DL1). These antibodies reacted primarily with single cells in 4-h-old plaque and with mixed-species microcolonies in 8-h-old plaque. Anti-RPS-reactive bacteria frequently formed microcolonies with anti-DL1-reactive bacteria and with other bacteria distinguished by general nucleic acid stains. In intergeneric coaggregation between streptococci and actinomyces, type 2 fimbriae of actinomyces recognize RPS on the streptococci. Cells reactive with antibody against type 2 fimbriae of Actinomyces naeslundii T14V (anti-type-2) were much less frequent than either subset of streptococci. However, bacteria reactive with anti-type-2 were seen in intimate association with anti-RPS-reactive cells. These results are the first direct demonstration of coaggregation-mediated interactions during initial plaque accumulation in vivo. Further, these results demonstrate the spatiotemporal development and prevalence of mixed-species communities in early dental plaque.

scholarly journals Development of UHPLC/Q-TOF Analysis Method to Screen Glycerin for Direct Detection of Process Contaminants 3-Monochloropropane-1,2-diol Esters (3-MCPDEs) and Glycidyl Esters (GEs)

Molecules ◽  
2021 ◽  
Vol 26 (9) ◽  
pp. 2449
Author(s):  
Lauren Girard ◽  
Kithsiri Herath ◽  
Hernando Escobar ◽  
Renate Reimschuessel ◽  
Olgica Ceric ◽  
...  
Keyword(s):  
Renal Failure ◽  
Solid Phase ◽  
Direct Detection ◽  
Screening Method ◽  
Extraction Procedure ◽  
Biodiesel Production ◽  
Food Contaminants ◽  
Exact Mass ◽  
Glycidyl Esters

The U.S. Food and Drug Administration’s (FDA′s) Center for Veterinary Medicine (CVM) has been investigating reports of pets becoming ill after consuming jerky pet treats since 2007. Renal failure accounted for 30% of reported cases. Jerky pet treats contain glycerin, which can be made from vegetable oil or as a byproduct of biodiesel production. Glycidyl esters (GEs) and 3-monochloropropanediol esters (3-MCPDEs) are food contaminants that can form in glycerin during the refining process. 3-MCPDEs and GEs pose food safety concerns, as they can release free 3-MCPD and glycidol in vivo. Evidence from studies in animals shows that 3-MCPDEs are potential toxins with kidneys as their main target. As renal failure accounted for 30% of reported pet illnesses after the consumption of jerky pet treats containing glycerin, there is a need to develop a screening method to detect 3-MCPDEs and GEs in glycerin. We describe the development of an ultra-high-pressure liquid chromatography/quadrupole time-of-flight (UHPLC/Q-TOF) method for screening glycerin for MCPDEs and GEs. Glycerin was extracted and directly analyzed without a solid-phase extraction procedure. An exact mass database, developed in-house, of MCPDEs and GEs formed with common fatty acids was used in the screening.

scholarly journals Ecological Importance of Cross-Feeding of the Intermediate Metabolite 1,2-Propanediol between Bacterial Gut Symbionts

2020 ◽  
Vol 86 (11) ◽  
Author(s):  
Christopher C. Cheng ◽  
Rebbeca M. Duar ◽  
Xiaoxi Lin ◽  
Maria Elisa Perez-Munoz ◽  
Stephanie Tollenaar ◽  
...  
Keyword(s):  
Trophic Interactions ◽  
Lactobacillus Reuteri ◽  
Trophic Interaction ◽  
Bacterial Strains ◽  
Content Type ◽  
Bifidobacterium Breve ◽  
Gut Symbionts ◽  
Gnotobiotic Mice ◽  
Ecological Importance ◽  
Isogenic Mutants

ABSTRACT Cross-feeding based on the metabolite 1,2-propanediol has been proposed to have an important role in the establishment of trophic interactions among gut symbionts, but its ecological importance has not been empirically established. Here, we show that in vitro growth of Lactobacillus reuteri (syn. Limosilactobacillus reuteri) ATCC PTA 6475 is enhanced through 1,2-propanediol produced by Bifidobacterium breve UCC2003 and Escherichia coli MG1655 from the metabolization of fucose and rhamnose, respectively. Work with isogenic mutants showed that the trophic interaction is dependent on the pduCDE operon in L. reuteri, which encodes the ability to use 1,2-propanediol, and the l-fucose permease (fucP) gene in B. breve, which is required for 1,2-propanediol formation from fucose. Experiments in gnotobiotic mice revealed that, although the pduCDE operon bestows a fitness burden on L. reuteri ATCC PTA 6475 in the mouse digestive tract, the ecological performance of the strain was enhanced in the presence of B. breve UCC2003 and the mucus-degrading species Bifidobacterium bifidum. The use of the respective pduCDE and fucP mutants of L. reuteri and B. breve in the mouse experiments indicated that the trophic interaction was specifically based on 1,2-propanediol. Overall, our work established the ecological importance of cross-feeding relationships based on 1,2-propanediol for the fitness of a bacterial symbiont in the vertebrate gut. IMPORTANCE Through experiments in gnotobiotic mice that employed isogenic mutants of bacterial strains that produce (Bifidobacterium breve) and utilize (Lactobacillus reuteri) 1,2-propanediol, this study provides mechanistic insight into the ecological ramifications of a trophic interaction between gut symbionts. The findings improve our understanding on how cross-feeding influences the competitive fitness of L. reuteri in the vertebrate gut and revealed a putative selective force that shaped the evolution of the species. The findings are relevant since they provide a basis to design rational microbial-based strategies to modulate gut ecosystems, which could employ mixtures of bacterial strains that establish trophic interactions or a personalized approach based on the ability of a resident microbiota to provide resources for the incoming microbe.

scholarly journals Oral Bacterial Communities in Individuals with Type 2 Diabetes Who Live in Southern Thailand

2013 ◽  
Vol 80 (2) ◽  
pp. 662-671 ◽  
Author(s):  
Kanokporn Kampoo ◽  
Rawee Teanpaisan ◽  
Ruth G. Ledder ◽  
Andrew J. McBain
Keyword(s):  
Type 2 Diabetes ◽  
Dental Caries ◽  
Bacterial Communities ◽  
Glycosylated Hemoglobin ◽  
Content Type ◽  
Supragingival Plaque ◽  
Southern Thailand ◽  
Acid Tolerant ◽  
Dna Profiles

ABSTRACTType 2 diabetes mellitus is increasingly common in Thailand and elsewhere. In the present investigation, the bacteriological composition of saliva and supragingival plaque in Thai diabetics with and without active dental caries and in nondiabetics was determined by differential culture and eubacterial DNA profiling. Potential associations between fasting blood sugar and glycosylated hemoglobin (biomarkers of current and historical glucose control, respectively) with decayed, missing, and filled teeth and with salivaryStreptococcusandLactobacilluscounts were also investigated. The incidence of active dental caries was greater in the Thai diabetics than in nondiabetics, and the numbers of total streptococci and lactobacilli were significantly higher in supragingival plaque from diabetics than in nondiabetics.Lactobacilluscounts in the saliva and supragingival plaque of diabetics with active caries were significantly higher than those in diabetics without active caries. Oral eubacterial DNA profiles of diabetic versus nondiabetic individuals and of diabetics with active caries versus those without active caries could not be readily differentiated through cluster analysis or multidimensional scaling. The elevated caries incidence in the Thai diabetics was positively associated with numbers of bacteria of the acidogenic/acid-tolerant generaStreptococcusandLactobacillus. Lactobacillusbacterial numbers were further elevated in diabetics with active caries, although salivary eubacterial DNA profiles were not significantly altered.

scholarly journals Complete Genome Sequences of Six Novel Macaca mulatta Papillomavirus Types Isolated from Genital Sites of Rhesus Monkeys in Hong Kong SAR, China

2018 ◽  
Vol 7 (22) ◽  
Author(s):  
Teng Long ◽  
Po Yee Wong ◽  
Wendy C. S. Ho ◽  
Robert D. Burk ◽  
Paul K. S. Chan ◽  
...  
Keyword(s):  
Hong Kong ◽  
Macaca Mulatta ◽  
Complete Genome ◽  
Rhesus Monkeys ◽  
Genome Sequences ◽  
Content Type ◽  
Complete Genomes ◽  
Hong Kong Sar

The complete genomes of six Macaca mulatta papillomavirus types isolated from genital sites of rhesus monkeys were characterized, and less than 72% identity with the complete L1 genes of known papillomaviruses was found. Macaca mulatta papillomavirus type 2 (MmPV2), MmPV3, and MmPV6 cluster into the genus Alphapapillomavirus, and MmPV4, MmPV5, and MmPV7 cluster into the genus Gammapapillomavirus.

scholarly journals Electroactivity of Phototrophic River Biofilms and Constitutive Cultivable Bacteria

2011 ◽  
Vol 77 (15) ◽  
pp. 5394-5401 ◽  
Author(s):  
Emilie Lyautey ◽  
Amandine Cournet ◽  
Soizic Morin ◽  
Stéphanie Boulêtreau ◽  
Luc Etcheverry ◽  
...  
Keyword(s):  
Stainless Steel ◽  
Cyclic Voltammetry ◽  
Oxygen Reduction ◽  
Saturated Calomel Electrode ◽  
Bacterial Strains ◽  
Phenotypic Properties ◽  
Content Type ◽  
Population Scale ◽  
River Biofilm ◽  
Biofilm Development

ABSTRACTElectroactivity is a property of microorganisms assembled in biofilms that has been highlighted in a variety of environments. This characteristic was assessed for phototrophic river biofilms at the community scale and at the bacterial population scale. At the community scale, electroactivity was evaluated on stainless steel and copper alloy coupons used both as biofilm colonization supports and as working electrodes. At the population scale, the ability of environmental bacterial strains to catalyze oxygen reduction was assessed by cyclic voltammetry. Our data demonstrate that phototrophic river biofilm development on the electrodes, measured by dry mass and chlorophyllacontent, resulted in significant increases of the recorded potentials, with potentials of up to +120 mV/saturated calomel electrode (SCE) on stainless steel electrodes and +60 mV/SCE on copper electrodes. Thirty-two bacterial strains isolated from natural phototrophic river biofilms were tested by cyclic voltammetry. Twenty-five were able to catalyze oxygen reduction, with shifts of potential ranging from 0.06 to 0.23 V, cathodic peak potentials ranging from −0.36 to −0.76 V/SCE, and peak amplitudes ranging from −9.5 to −19.4 μA. These isolates were diversified phylogenetically (Actinobacteria,Firmicutes,Bacteroidetes, andAlpha-,Beta-, andGammaproteobacteria) and exhibited various phenotypic properties (Gram stain, oxidase, and catalase characteristics). These data suggest that phototrophic river biofilm communities and/or most of their constitutive bacterial populations present the ability to promote electronic exchange with a metallic electrode, supporting the following possibilities: (i) development of electrochemistry-based sensors allowingin situphototrophic river biofilm detection and (ii) production of microbial fuel cell inocula under oligotrophic conditions.

scholarly journals Natural Disruption of Two Regulatory Networks in Serotype M3 Group A Streptococcus Isolates Contributes to the Virulence Factor Profile of This Hypervirulent Serotype

2014 ◽  
Vol 82 (5) ◽  
pp. 1744-1754 ◽  
Author(s):  
Tram N. Cao ◽  
Zhuyun Liu ◽  
Tran H. Cao ◽  
Kathryn J. Pflughoeft ◽  
Jeanette Treviño ◽  
...  
Keyword(s):  
Virulence Factor ◽  
Regulatory Networks ◽  
Molecular Mechanisms ◽  
Group A Streptococcus ◽  
Regulatory System ◽  
Mrna Levels ◽  
Bacterial Strains ◽  
Content Type ◽  
Small Regulatory Rna ◽  
Group A

ABSTRACTDespite the public health challenges associated with the emergence of new pathogenic bacterial strains and/or serotypes, there is a dearth of information regarding the molecular mechanisms that drive this variation. Here, we began to address the mechanisms behind serotype-specific variation between serotype M1 and M3 strains of the human pathogenStreptococcus pyogenes(the group AStreptococcus[GAS]). Spatially diverse contemporary clinical serotype M3 isolates were discovered to contain identical inactivating mutations within genes encoding two regulatory systems that control the expression of important virulence factors, including the thrombolytic agent streptokinase, the protease inhibitor-binding protein-G-related α2-macroglobulin-binding (GRAB) protein, and the antiphagocytic hyaluronic acid capsule. Subsequent analysis of a larger collection of isolates determined that M3 GAS, since at least the 1920s, has harbored a 4-bp deletion in thefasCgene of thefasBCAXregulatory system and an inactivating polymorphism in therivRregulator-encoding gene. ThefasCandrivRmutations in M3 isolates directly affect the virulence factor profile of M3 GAS, as evident by a reduction in streptokinase expression and an enhancement of GRAB expression. Complementation of thefasCmutation in M3 GAS significantly enhanced levels of the small regulatory RNA FasX, which in turn enhanced streptokinase expression. Complementation of therivRmutation in M3 GAS restored the regulation ofgrabmRNA abundance but did not alter capsule mRNA levels. While important, thefasCandrivRmutations do not provide a full explanation for why serotype M3 strains are associated with unusually severe invasive infections; thus, further investigation is warranted.

Red meat consumption and type 2 diabetes mellitus risk

2015 ◽  
Vol 45 (4) ◽  
pp. 524-541
Author(s):  
Emma Derbyshire ◽  
Carrie Ruxton
Keyword(s):  
Diabetes Mellitus ◽  
Type 2 Diabetes ◽  
Type 2 Diabetes Mellitus ◽  
Clinical Studies ◽  
Meat Consumption ◽  
Red Meat ◽  
Review Literature ◽  
Processed Meat ◽  
Content Type

Purpose – This review aims to evaluate and review literature published in the area of rising concerns that red meat consumption may be associated with risk of type 2 diabetes mellitus (T2DM), although there have been discrepancies between study findings, and put the findings into context. Design/methodology/approach – Using the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) guidelines, a systematic literature review was undertaken to locate and summarise relevant studies which included epidemiological and clinical studies published between 2004 and 2014. Findings – A total of 23 studies were found, with 21 epidemiological and two clinical studies meeting the criteria. Overall, the totality of the evidence indicates that while processed meat consumption appears to be associated with T2DM risk, the effect is much weaker for red meat, with some associations attenuated after controlling for body weight parameters. Where studies have considered high intakes in relation to T2DM risk, meat intake has tended to exceed 600 g per week. Therefore, keeping red meat intakes within recommended guidelines of no more than 500 g per week, while opting for lean cuts or trimming fat, would seem to be an evidence-based response. Research limitations/implications – The majority of studies conducted to date have been observational cohorts which cannot determine cause and effect. Most of these used food frequency questionnaires which are known to be subject to misclassification errors (Brown, 2006). Clearly, more randomised controlled trials are needed to establish whether red meat consumption impacts on markers of glucose control. Until then, conclusions can only be viewed as speculative. Originality/value – This paper provides an up-to-date systematic review of the literature, looking at inter-relationships between red meat consumption and T2DM risk.

scholarly journals First Description of Two Sequence Type 2 Acinetobacter baumannii Isolates Carrying OXA-23 Carbapenemase in Pagellus acarne Fished from the Mediterranean Sea near Bejaia, Algeria

2016 ◽  
Vol 60 (4) ◽  
pp. 2513-2515 ◽  
Author(s):  
Soumia Brahmi ◽  
Abdelaziz Touati ◽  
Axelle Cadière ◽  
Nassima Djahmi ◽  
Alix Pantel ◽  
...  
Keyword(s):  
Acinetobacter Baumannii ◽  
Mediterranean Sea ◽  
Sequence Type ◽  
Content Type ◽  
Carbapenem Resistant ◽  
Selective Agar ◽  
Agar Media ◽  
The Mediterranean ◽  
First Time

ABSTRACTTo determine the occurrence of carbapenem-resistantAcinetobacter baumanniiin fish fished from the Mediterranean Sea near the Bejaia coast (Algeria), we studied 300 gills and gut samples that had been randomly and prospectively collected during 1 year. After screening on selective agar media, using PCR arrays and whole-genome sequencing, we identified for the first time two OXA-23-producingA. baumanniistrains belonging to the widespread sequence type 2 (ST2)/international clone II and harboring aminoglycoside-modifying enzymes [aac(6′)-Ib andaac(3′)-I genes].

scholarly journals Dairy Heifers Naturally Exposed toFasciola hepaticaDevelop a Type 2 Immune Response and Concomitant Suppression of Leukocyte Proliferation

2017 ◽  
Vol 86 (1) ◽  
Author(s):  
John Graham-Brown ◽  
Catherine Hartley ◽  
Helen Clough ◽  
Aras Kadioglu ◽  
Matthew Baylis ◽  
...  
Keyword(s):  
Immune Response ◽  
Immune Responses ◽  
Peripheral Blood ◽  
Serum Antibody ◽  
Enzyme Linked Immunosorbent Assay ◽  
Mixed Effect ◽  
Content Type ◽  
Grazing Season ◽  
Type 2 Immune Response

ABSTRACTFasciola hepaticais a parasitic trematode of global importance in livestock. Control strategies reliant on anthelmintics are unsustainable due to the emergence of drug resistance. Vaccines are under development, but efficacies are variable. Evidence from experimental infection suggests that vaccine efficacy may be affected by parasite-induced immunomodulation. Little is known about the immune response toF. hepaticafollowing natural exposure. Hence, we analyzed the immune responses over time in calves naturally exposed toF. hepaticainfection. Cohorts of replacement dairy heifer calves (n= 42) with no prior exposure toF. hepatica, on three commercial dairy farms, were sampled over the course of a grazing season. Exposure was determined through anF. hepatica-specific serum antibody enzyme-linked immunosorbent assay (ELISA) and fluke egg counts. Concurrent changes in peripheral blood leukocyte subpopulations, lymphocyte proliferation, and cytokine responses were measured. Relationships between fluke infection and immune responses were analyzed by using multivariable linear mixed-effect models. All calves from one farm showed evidence of exposure, while cohorts from the remaining two farms remained negative over the grazing season. A type 2 immune response was associated with exposure, with increased interleukin-4 (IL-4) production, IL-5 transcription, and eosinophilia. Suppression of parasite-specific peripheral blood mononuclear cell (PBMC) proliferation was evident, while decreased mitogen-stimulated gamma interferon (IFN-γ) production suggested immunomodulation, which was not restricted to parasite-specific responses. Our findings show that the global immune response is modulated toward a nonproliferative type 2 state following natural challenge withF. hepatica. This has implications in terms of the timing of the administration of vaccination programs and for host susceptibility to coinfecting pathogens.

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