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Objective To compare the bacterial community profiles present in periodontium and root canals of the same tooth diagnosed as combined periodontal-endodontic lesions by using denaturing gradient gel electrophoresis (DGGE).Methods Samples were collected from 13 extracted teeth with advanced periodontitis,endodontic samples from root tip 1/3 root canal,and periodontal samples from the corresponding neighboring periodontium.Genomic DNA was collected for the following universal bacterial primersPCR.The PCR products were then loaded on the DGGE gels to gain separate bands.The typical DGGE bands were excised,PCR-cloned and sequenced.Results The number of bands,which was indicative of the number of bacterial species,was compared intra-group (periodontal and pulpal specimen from the same tooth).The difference was statistically significant (P＜0.01),but there was no positive correlation between them.The similarity (Dice Coefficient) between them was 13.1％-62.5％.Taxa identified through BLAST (≥98％ identity) were Campylobacter,Fusobacterium,Neisseria,et al in the periodontium,and Mogibacterium,Corynebacterium,Actinomyces,et al in the root canals.Conclusion Common bacteria existed between them,but not all of the periodontal bacteria would appear in neighboring root canal; and the bacteria in the root canal are not completely from neighboring periodontal tissue.The original bacteria in the root canals may resuscitate and enrich the bacterial community.In combined periodontal-endodontic lesions (periodontal source),it is probable that new species existed to be confirmed either in the periodontium or in the root canal.
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<p><b>OBJECTIVE</b>To construct strains containing green fluorescent protein (GFP) to study gene regulation in Saccharomyces albicans cells during the infection process.</p><p><b>METHODS</b>pACT1-GFP was constructed, and Saccharomyces albicans CAI4 was transformed. The expression of GFP in yeast and hyphal compartments was observed with microscopy.</p><p><b>RESULTS</b>99% of Saccharomyces albicans cells containing pACT1-GFP fusion displayed significant fluorescence levels both in the yeast and hyphal compartments. The fluorescence intensity in two compartments had no obvious difference.</p><p><b>CONCLUSION</b>pACT1-GFP can be expressed stably in the yeast cells.</p>
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Humans , Candida albicans , Green Fluorescent Proteins , Plasmids , Saccharomyces , Saccharomyces cerevisiaeABSTRACT
Objective To illuminate the effect of persisters on antifungal therapy by infecting Caenorhabditis elegans as a live-animal model with Candida albicans isolates of different persister levels, treating them with amphotericin B and comparing the survival rate. Methods Glp-4 (bn2ts); sek-1 (km4) worms were synchronized and grown to sterile to L4-stage, put on different Candida albicans strains lawns separately for 2 h. Dispensed 15-20 worms per well of the 96-well plate, and added serial dilutions of amphotericin B for each strain group. Wells filled without any amphotericin B were used as negative controls intra-group. Incubated the plate at 25C for 5 days, counted the survival rate of each well. Results Compared with negative controls, survival rate of drug wells in each group increased. In the same drug concentration, the increase for high-persister group was significantly lower than that for low-persister group (P＜0.01). Conclusion Caenorhabditis elegans provides a model for the study of persisters and antifungal pharmacodynamics.The drug tolerance of persisters may be a critical component responsible for antifungal drug failure and relapsing infections.
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Objective To construct the recombinant plasmid pEGFP-N1-SrV+ and evaluate the expression of SrV+in mammalian 293T cells.nethods srv+.a gene encoding the vailable region of the surface protein of the Streptococcus mutans OMZ175.was cloned chemically based on its reported nucleotide sequence.The eukaryotic expression plasmid,pEGFP-N1-SrV+,was constructed by introducing the srv+ gene into the Kpn Ⅰ/Xho Ⅰ site of pEGFP-NI.The recombinant plasmid pEGFP-N1-SrV+was transfected into 293T cells with lipofectamine and the expression level of SrV+was evaluated.Results The eukaryotic expression plasmid pEGFP-N1-SrV+was constructed successfully.GFP was observed by green fluorescent microscope.and a 72 × 1 03 protein was detected bv Westem blot.Real-time RT-PCR analysis revealed that the expression of the pEGFP-N1-SrV+in 293T was excellent and significant compared the control group. Conclusion The recombinant plasmid pEGFP-N1-SrV+was successfully constructed.which could encode the expression of SrV+after transfected into the mammalian 293T Cells.
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Objective To investigate the effect of killing the biofilm persisters by miconazole combined with two compound which can inhibit the drug efflux of C. albicans. Methods Lab reference strains of C. albicans YEM30(CAF2-1) formed the mature biofilm in the 96 well plates, and then treated with miconazole combined with Enniatin B (CDR1 inhibitor) and Milbemycins ot25 (CDRI/CDR2 inhibitor) respectively. After incubated for 48 hours by CFU counting on the YPD plates, the analysis of persisters with SAS8.0 software package for q test. Results Miconazole combined with drug efflux inhibitor can kill more persisters than miconazole alone(P <0.001), and combining with Enniatin B have a better results in eliminating the biofilm persisters than with Milbemycins α25. Conclusion Antifungal drugs combined with drug efflux pump inhibitors can kill more strains which can tolerate very high concentration of antifungal drugs. And searching the potential drug efflux pump inhibitors may be a new way for eliminating the persisters in biofilm, and consequently controlling the chronic recurrent fungal infectious diseases.
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OBJECTIVE To compare the results of three kinds of Candida albicans biofilm model systems in vitro,and observe the dynamic course of C.albicans biofilm formation.METHODS C.albicans model strain ATCC 90038 formed biofilm structure on 96 well microtiter plates,on the glass plates in 6 well cell culture plates,and on the continuous culture systems-chemostat,which was observed by fluorescent microscope,and by XTT reduction method to quantitatively analyze the formation of biofilm.RESULTS All of the three kinds of biofilm model systems could form mature biofilm structure,and the quantitative analysis of biofilm formation indicated that three methods were significantly correlated.CONCLUSIONS These three model systems are all ideal methods for studying the C.albicans biofilm,we should choose the appropriate method according to objective of the study.
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Objective:To investigate the gene expression variety of different genotype of F-ATPase subunit uncEBF in Streptococcus mutans (S.mutans) and to evaluate the relationship among uncEBF gene expression levels, genotypes and the acidurance ability of S.mutans. Methods:The relative expression quantity of uncEBF gene against the housekeeping gene recA was determined by the two-step method of semi-quantitative RT-PCR in 18 clinical isolates of S.mutans(7 with genotype A uncEBF and 11 with genotyp B,10 with high acidurance and 8 with low). A gel documentation system and QUANTITY ONES software were used to assay the data. Results:uncEBF mRNA expression level in the isolates with genotype A uncEBF was higher than that in those with genotype B(P