不同根管冲洗液和冲洗方法对粪肠球菌清除作用的体外研究

目的 比较不同冲洗液和冲洗方法对根管内粪肠球菌的清除效果。方法 建立120颗人完整单根管前磨牙粪肠球菌感染根管模型,随机分组,分别采用不同冲洗液(0.9% NaCl,0.5% NaClO,3% NaClO)及冲洗方法(注射针头冲洗,超声荡洗,RinsEndo系统处理,超声荡洗协同RinsEndo系统联用)进行根管清理。无菌吸潮纸尖取样,平板菌落计数法计算CFU值,计算细菌清除率,运用SPSS 22.0软件进行统计分析,P<0.05时差异具有统计学意义。结果 使用0.9% NaCl及0.5% NaClO冲洗液时,注射针头冲洗组细菌清除率明显低于超声荡洗及RinsEndo系统处理组(P<0.001);使用3% NaClO冲洗液的各组不同的冲洗方法,细菌清除率的差异无统计学意义(P=0.556)。而无论采用哪种冲洗方法,3% NaClO溶液的细菌清除效果均优于0.5% NaClO溶液和0.9% NaCl溶液(P<0.001)。结论 不同根管冲洗液在一定程度上会影响根管冲洗方法对根管内粪肠球菌的清除效果。     

Er：YAG激光对根管内粪肠球菌影响的体外研究

目的本研究通过体外实验比较Er：YAG激光在不同频率的杀菌效果,及其在直根管及弯曲根管内的杀菌效果。方法选取50颗直单根管牙齿分F1、F2、F3、FP、FN 5组,比较Er：YAG激光在不同频率的杀菌效果;选取直根管30颗、弯曲根管20颗分5组比较Er：YAG激光对直根管及弯曲内粪肠球菌影响。建立粪肠球菌感染模型,FP组、E1组、E2组2.5%NaOCl溶液冲洗2min。FN组和E5组0.9%无菌生理盐水冲洗2min。其余各组根管内干燥后,激光照射12s,共4次,每次间隔10秒。根管消毒前后取样,检测粪肠球菌的菌落数目。结果①不同频率激光对根管内粪肠球菌影响的比较：冲洗或消毒后,F1组、F2组、F3组、FP组杀菌率两两比较没有统计学意义（P〉0.05）。②Er：YAG激光对直根管及弯曲内粪肠球菌影响的比较：冲洗或消毒后,E1、E2、E3组杀菌率分别为87.90%、87.02%和87.20%,两两比较没有统计学意义（P〉0.05）,但是E4组杀菌率为74.64%,与E1组、E2组、E3组两两比较有统计学意义（P〈0.05）。结论 Er：YAG激光是一种有效的根管消毒器械。不同频率的激光杀菌效果相似,但是在弯曲根管内的杀菌效果低于在直根管内。     

高功率半导体激光对复杂根管消毒效果的体外研究

目的 评价高功率半导体激光联合次氯酸钠对体外复杂根管的消毒效果。方法 通过CBCT筛选含峡区的离体牙42颗，体外建立复杂根管感染模型，将离体牙随机分为4组，A组：半导体激光组+0.9% NaCl溶液； B组：半导体激光+5.25% NaClO； C组:5.25% NaClO； D组：空白对照组；每组10颗牙齿，经消毒处理后收集冲洗液，进行细菌培养、菌落形成单位计数、SEM观察及细菌活死染色后激光聚焦显微镜（ CLSM）观察分析，定量比较各组对粪肠球菌的杀灭效果。结果 ① A、B、C组处理后的杀菌率分别为33.9%、98.4%和82.8%，均高于D组的3.68%（ P<0.05）,其中B组杀菌率最高； ②扫描电镜结果显示：激光结合次氯酸钠组获得最好的根管壁清理效果； ③ CLSM图像荧光强度IOD值分析结果显示： B组红色荧光强度高于其余3组（ P<0.05）。结论 半导体激光辅助根管消毒有助于复杂根管（含峡区）的消毒；高功率（ 2.5 W）半导体激光结合传统根管化学消毒值得推广。     

不同根管消毒方法对粪肠球菌清除作用的体外研究

目的:比较被动超声荡洗(passive ultrasonic irrigation,PUI)与半导体激光,及两者联用对根管内粪肠球菌的清除作用,并与3％NaClO消毒效果进行比较,为临床选择根管消毒方法提供参考.方法:选取50颗成人单根管离体前磨牙,建立粪肠球菌生物膜感染根管模型,随机将其均分为5组并做不同处理.A组为生理盐水冲洗组,B组为3％NaClO溶液冲洗组(阳性对照组),C组为PUI处理组,D组为半导体激光处理组,E组为PUI联合半导体激光处理组.选用纸尖法取样,稀释培养48 h后,计算每个样本菌落形成单位(colony-forming units,CFU)值.采用SAS 8.02软件包对数据进行统计学分析.结果:PUI处理组、半导体激光处理组及联合处理组样本的CFU值,与生理盐水冲洗组相比均存在显著差异(P＜0.01),3组结果均显著低于生理盐水冲洗组,而3组之间则无显著差异(P＞0.05).3％NaClO溶液冲洗组(阳性对照组)的CFU值均显著低于其余4组(P＜0.01).结论:PUI、半导体激光消毒及其两者联用均对粪肠球菌生物膜具有显著消毒效果,显著优于单纯使用生理盐水冲洗,但三者之间效果相当;3％NaClO冲洗对粪肠球菌生物膜具有最强的消毒作用.     

Nd:YAG激光和Er:YAG激光对根管内粪肠球菌杀灭效果的研究

［摘要］ 目的 观察Nd:YAG激光、Er:YAG激光及两者联用对根管内粪肠球菌的杀灭效果。方法 选取离体牙建立粪肠球菌感染模型,随机分为五组：A组：生理盐水组;B组：1%次氯酸钠溶液组;C组：Nd:YAG激光组;D组：Er:YAG激光组;E组：Nd:YAG激光+Er:YAG激光组。通过细菌培养和扫描电镜观察对比各组的杀菌效果。结果 细菌培养和扫描电镜结果显示：A组杀菌率最低,B组杀菌率最高,E组次高。除C组和D组间杀菌率相近外（P>0.05）,各组间均有统计学差异（P<0.05）。结论 Nd:YAG激光和Er:YAG激光均有一定的根管杀菌效果,两者联用效果更佳,可作为传统消毒方法的补充。     

不同冲洗方法对粪肠球菌感染根管的抗菌性研究

目的比较超声、Er,Cr：YSGG激光及Er：YAG激光辅助1%次氯酸钠（NaOCl）溶液冲洗对人离体牙根管表面粪肠球菌生物膜及根尖区不同深度牙本质小管内粪肠球菌的杀灭效果。 方法单直根管下颌前磨牙42颗,建立粪肠球菌生物膜感染的根管模型,采用随机字表法随机抽取2颗确定建成粪肠球菌生物膜感染根管模型,剩余40颗牙采用随机数字表法按随机对照原则分为5组,每组8颗。A组：5.25% NaOCl联合17%乙二胺四乙酸（EDTA）注射器冲洗;B组：0.9%氯化钠溶液注射器冲洗;C组：1% NaOCl溶液超声荡洗;D组：1% NaOCl溶液Er：YAG激光活化冲洗;E组：1% NaOCl溶液Er,Cr：YSGG激光活化冲洗。按分组进行处理后取样菌落计数,计算灭菌率。使用SPSS 17.0统计软件对实验数据进行方差齐性及正态性检验比较各组间和组内的灭菌率。 结果（1）组间比较：对根管壁表面,各组冲洗方法灭菌率比较,B组（5.74%）相似文献   

Er:YAG激光联合次氯酸钠对粪肠球菌杀菌效果的研究

目的:比较掺铒钇铝-石榴石脉冲(Er:YAG)激光联合不同浓度次氯酸钠对根管内粪肠球菌杀菌效果的研究。方法:选择新鲜拔除的人单根管离体前磨牙建立粪肠球菌根管感染模型75个,随机分为5组,每组15个,分别进行如下处理:A组:5.25%次氯酸钠单独冲洗;B组:Er:YAG激光+5.25%次氯酸钠冲洗;C组:1%次氯酸钠单独冲洗;D组:Er:YAG激光+1%次氯酸钠冲洗。E组:空白对照。采集5组根管内的细菌进行培养计数并对结果进行卡方检验(Chi-square test)。结果:A、B、D三组均能完全杀灭根管内的粪肠球菌;C组未能完全杀灭根管内的粪肠球菌。15个培养皿中有11个可见粪肠球菌菌落。A、B、D三组间杀菌效果无差异且均显著优于C组。结论:高浓度次氯酸钠可以完全杀灭根管内的粪肠球菌,低浓度次氯酸钠不能完全杀灭根管内的粪肠球菌;Er:YAG激光可以显著增强低浓度次氯酸钠的杀菌作用。     

Nd:YAP激光联合自酸蚀粘接和树脂修复治疗牙本质敏感的临床研究

目的 探讨Nd：YAP激光联合自酸蚀粘接系统对牙本质敏感的临床疗效。方法 选取108颗需要树脂充填的牙本质敏感患牙,随机分为实验组和对照组。实验组使用Nd：YAP激光处理牙面后,联合自酸蚀粘接系统和树脂充填修复;对照组直接使用自酸蚀粘接系统和树脂充填修复,分别在治疗后6个月和12个月对牙敏感性,充填体固位性,充填体边缘密合性和总体疗效进行评估。结果 治疗后12个月随访,实验组牙齿敏感度改善情况、充填体固位性、充填体边缘密合度均优于对照组,差异有统计学意义（P<0.05）;实验组总体疗效高于对照组,差异有统计学意义（P<0.05）。结论 Nd：YAP激光联合自酸蚀粘接系统对改善牙本质敏感疗效明显,充填体固位力和边缘密合度优,适合用于需要充填的牙本质敏感患者。     

超声冲洗用于慢性牙髓炎一次法根管治疗术的临床评价

目的 评价根管超声冲洗技术对成人磨牙慢性牙髓炎一次法根管治疗术短期疗效的影响。方法 168 颗患牙按掷硬币的方法分为超声冲洗组86 颗和常规组82 颗,局麻下开髓、拔髓和根管预备,根管充填前常规组用2 mL 5.25% 的次氯酸钠溶液冲洗;超声冲洗组用2ml5.25% 次氯酸钠溶液注入根管,15号超声锉荡洗2min,期间不断补充新鲜液体。2组最后均使用17% EDTA 冲洗,吸干热牙胶垂直加压充填根管,窝洞暂封。3 天后复诊完成冠部充填。治疗后观察根管充填质量及侧枝根管充填情况、3天内疼痛发生情况以及1年后的治疗疗效。结果 超声组术后即刻侧支根管充填率提高,两组差异有统计学意义(P<0.05);根管充填后3 天内超声组疼痛发生率明显低于常规组(P<0.05);2 组1 年后疗效差异无统计学意义(P>0.05)。结论 超声冲洗能短期内降低术后疼痛发生率,提高侧支根管充填率,有很好的临床应用效果。     

PIPS联合纳米银对根管粪肠球菌抗菌效果研究

目的 探究激光引发光声流系统(PIPS)和纳米银(AgNPs)联合使用对根管内粪肠球菌生物膜的抗菌效果。方法 收集36颗单根管离体牙,建立粪肠球菌感染根管实验模型,将样本随机分成6组,采用0.9%NaCl、2%NaClO、0.1%AgNPs溶液分别联合传统手动冲洗(CNI)或PIPS对根管进行冲洗,使用菌落计数法测定治疗前后根管内粪肠球菌生物膜菌落数,并计算菌落计数减少的百分比。结果 所有实验组粪肠球菌生物膜的抑制效果均强于对照组(P<0.05),使用PIPS辅助0.9%NaCl、2%NaClO、0.1%AgNPs冲洗组的降幅均分别大于CNI辅助0.9%NaCl、2%NaClO、0.1%AgNPs冲洗组(P<0.05)。PIPS辅助0.1%AgNPs冲洗组的降幅明显大于PIPS辅助2%NaClO冲洗组(P<0.05)。结论 PIPS辅助AgNPs溶液冲洗可以显著提高根管内粪肠球菌生物膜的清除效果。     

Bioactivity and cellular structure of Candida albicans and Candida glabrata biofilms grown in the presence of fluconazole

Objective

The aim of this study was to evaluate whether fluconazole (FLZ) could affect the bioactivity and cellular structure of Candida albicans or Candida glabrata biofilms grown in the presence of FLZ.

Materials and methods

Tokens were fabricated using poly(methylmethacrylate) resin (PMMA) in a hot water bath. Salivary pellicles were formed on the PMMA surface, and biofilms of a reference strain and two clinical isolates of C. albicans (ATCC 90028, P01 and P34) and C. glabrata (ATCC 2001, P11 and P31) were developed for a period of 48 h. Control and experimental groups were formed. FLZ at the bioavailable concentration in saliva (2.56 μg/mL) was added to the medium of the experimental group. The culture mediums of the control and experimental groups were changed after 24 h. The bioactivities of the biofilms were evaluated using an XTT reduction colorimetric assay. The cellular structure was analysed by confocal scanning laser microscopy and by transmission electron microscopy. The data were analysed by the independent sample Student's t-test, with the significance level set at 5%.

Results

The presence of FLZ decreased the bioactivity of all C. albicans biofilms (p < 0.001), however, it did not change the cellular structure of C. albicans P34. Regarding the C. glabrata biofilm bioactivity and structure, no statistically significant differences were found between the control and experimental groups.

Conclusion

FLZ, at the bioavailable concentration present in saliva, interferes with the development of C. albicans biofilms, but does not interfere with the development of C. glabrata biofilms.     

Genetic diversity and exoenzyme activities of Candida albicans and Candida dubliniensis isolated from the oral cavity of Brazilian periodontal patients

Objective

Mucosal surfaces are the primary oral reservoirs of Candida species, but these species can also be found in subgingival biofilm. The present study investigated the genetic diversity and production of exoenzymes of C. albicans and C. dubliniensis isolated from the oral cavity of systemically healthy patients with periodontitis.

Design

Fifty-three patients were analysed. Samples were collected from three oral cavity sites (periodontal pocket, gingival sulci and oral mucosa), plated and, after isolation, suspect strains of C. albicans and C. dubliniensis were identified by PCR. The genetic diversity of the isolates was evaluated by RAPD and the activities of the secreted aspartyl proteinases and phospholipases were evaluated by the agar plate method.

Results

Twenty-one patients showed positive results for Candida spp. There were no statistically significant differences between genders, or between sites. C. albicans was the most frequently found specie, while C. dubliniensis was isolated from the periodontal pocket of only one patient. Sixteen genotypes were detected among the C. albicans isolates, and one among the C. dubliniensis isolates. The similarity coefficient (S_SM) values among the C. albicans genotypes ranged from 0.684 to 1.0 with an average of 0.905 ± 0.074. All isolates produced high levels of Saps and most of them produced high levels of phospholipases. No relationship was found between the genotypes and the pattern of enzymatic production. There was no association between specific genotypes and their site of isolation.

Conclusions

The results of the present study suggest that genetically homogeneous strains of C. albicans are present in the oral cavity of patients with periodontitis and that these strains are capable of producing high levels of exoenzyme.     

The effect of Streptococcus mutans and Candida glabrata on Candida albicans biofilms formed on different surfaces

Although Candida containing biofilms contribute to the development of oral candidosis, the characteristics of multi-species Candida biofilms and how oral bacteria modulate these biofilms is poorly understood. The aim of this study was to investigate interactions between Candida albicans and either Candida glabrata or Streptococcus mutans in biofilms grown on various surfaces, with or without saliva. Hydroxyapatite (HA), polymethylmetacrylate (PMMA) and soft denture liner (SL) discs were used as substratum. Counts of viable micro-organisms in the accumulating biofilm layer were determined and converted to colony forming units per unit surface area. Confocal laser scanning microscopy was used to characterize biofilms and to quantitate the number of hyphae in each condition tested. Viable counts of C. albicans and C. glabrata per mm(2) decreased in the order HA>PMMA>SL (p<0.05). Biofilms grown on saliva-coated specimens harboured fewer C. glabrata than uncoated specimens (p<0.05). Glucose and the presence of S. mutans suppressed C. albicans hyphal formation. Dual Candida species biofilms did not show competitive interaction between the two species. We conclude that Candida biofilms are significantly affected by saliva, substratum type and by the presence of other micro-organisms.     

Photoinactivation of F. nucleatum and P. gingivalis using the ruthenium-based RD3 sensitizer and a conventional halogen lamp

Objective

The photodynamic therapy (PDT) is an alternative method to suppress oral pathogens by the activation of a photosensitizer with laser light. The aim of this study was to investigate the phototoxic effect of three ruthenium-based photosensitizers on Fusobacterium nucleatum and Porphyromonas gingivalis.

Methods

In this in vitro study F. nucleatum and P. gingivalis were incubated with three photosensitizers: (i) a hydrophobic tris-(4,7-diphenyl-1,10-phenanthroline)-ruthenium(II)-dication (RD3), (ii) a hydrophilic tris-[(1,10-phenanthroline-4,7-diyl)-bis-(benzenesulfonato)]-ruthenate tetra-anion (RSD3) and (iii) a lower hydrophilic tris-(2,2′-bipyridine)-ruthenium(II) dication (RBY). The subsequent irradiation was done with blue-band halogen light (450–485 nm) for 20 s using a conventional polymerizer. Control samples consisted of bacterial cell suspension irradiated and non-irradiated in the absence of photosensitizer or incubated with the photosensitizer without irradiation. Bacterial inactivation was determined by the numbers of colony-forming units (cfu/ml) after anaerobic cultivation.

Results

The RD3 photosensitizer reduced the viability of F. nucleatum by 4-log 10 and of P. gingivalis completely after irradiation for 20 s. The viability loss correlated significantly with the concentration of the RD3 photosensitizer and reached a peak at a concentration of 12.5 μM (p < 0.05). The RSD3 and RBY photosensitizers had distinctly lower phototoxic effects in comparison to RD3.

Conclusion

The RD3 photosensitizer showed a phototoxic effect on F. nucleatum and P. gingivalis. The results suggest that the application of the RD3 photosensitizer under visible light may be helpful as an adjunct treatment approach to the inactivation of periodontopathogenic bacteria.     

Microbicidal efficacy of thiocyanate hydrogen peroxide after adding lactoperoxidase under saliva loading in the quantitative suspension test

Objective

As shown in the quantitative suspension test adding lactoperoxidase to a thiocyanate (SCN⁻) hydrogen peroxide (H₂O₂) combination over the physiological saliva level has significant positive antimicrobial effects to a level of totally killing Streptococcus mutans, Streptococcus sanguinis, and Candida albicans. The aim of this study was to evaluate this positive effect under human saliva loading.

Methods

The bactericidal and fungicidal effect of lactoperoxidase was evaluated in a quantitative suspension test by using two test mixtures of a 2.0% thiocyanate and 1.2% hydrogen peroxide solution, one without (Group A) and one with (Group B) lactoperoxidase under saliva loading. Following the quantitative suspension tests (EN-13727/EN-13624), the growth of surviving bacteria and fungi in a nutrient broth was measured. The exposure times were restricted to 1, 3, 5, and 15 min. All statistical analyses were carried out with SPSS 11.5.

Results

In the quantitative suspension test, the combination of thiocyanate and hydrogen peroxide showed relatively low antimicrobial effectiveness on S. mutans, S. sanguinis, and C. albicans in the presence of human saliva at measured time points in comparison to the mixture with lactoperoxidase, which showed a high bactericidal activity within 15 min (S. mutans and S. sanguinis) and fungicidal activity within 3 min (C. albicans).

Conclusion

The antimicrobial effectiveness of the tested thiocyanate hydrogen peroxide combination was increased significantly by adding lactoperoxidase in the quantitative suspension test under human saliva loading.     

基于PADTM Plus的光活化消毒技术杀灭白色念珠菌的体外实验研究

目的 研究基于PAD^TM Plus的光活化消毒技术(photo-activated disinfection,PAD)体外杀灭白色念珠菌的效果。方法 选取白色念珠菌标准株SC5314配制菌悬液。光活化消毒仪输出功率为750 mW，光敏剂为甲苯胺蓝(Toluidine Blue O, TBO)溶液，有效浓度0.75 mg/mL，光源为波长635 nm的LED红光。实验分为空白对照组(P-L-)、单纯光敏剂孵育60 s组(P+T1+L-)、单纯光敏剂孵育120 s组(P+T2+L-)、单纯光照组(P-L+)、PAD孵育60 s组(P+T1+L+)、PAD孵育120 s组(P+T2+L+)，光照时间均为60s。根据不同分组的处理方法对白色念珠菌悬液进行处理后接种于ChROMagar培养基，并于37℃环境下培养48 h，菌落计数以每毫升菌落形成单位(CFU/mL)表示。采用统计学方法分析结果。结果 P-L-组、P+T1+L-组、P+T2+L-组与P-L+组的对比其菌落对数的差异均无统计学意义(P>0.05)，而P+T1+L+组和P+T2+L+组与P-L-组的对比差异...     

Susceptibility of Candida albicans and Candida dubliniensis to erythrosine- and LED-mediated photodynamic therapy

The effect of erythrosine- and LED-mediated photodynamic therapy (PDT) on planktonic cultures and biofilms of Candida albicans and Candida dubliniensis was evaluated. Planktonic cultures of standardized suspensions (10⁶ cells/mL) of C. albicans and C. dubliniensis were treated with erythrosine concentrations of 0.39–200 μM and LEDs in a 96-well microtiter plate. Biofilms formed by C. albicans and C. dubliniensis in the bottom of a 96-well microtiter plate were treated with 400 μM erythrosine and LEDs. After PDT, the biofilms were analysed by scanning electron microscopy (SEM). The antimicrobial effect of PDT against planktonic cultures and biofilms was verified by counting colony-forming units (CFU/mL), and the data were submitted to analysis of variance and the Tukey test (P < 0.05). C. albicans and C. dubliniensis were not detectable after PDT of planktonic cultures with erythrosine concentrations of 3.12 μM or higher. The CFU/mL values obtained from biofilms were reduced 0.74 log₁₀ for C. albicans and 0.21 log₁₀ for C. dubliniensis. SEM revealed a decrease in the quantity of yeasts and hyphae in the biofilm after PDT. In conclusion, C. albicans and C. dubliniensis were susceptible to erythrosine- and LED-mediated PDT, but the biofilms of both Candida species were more resistant than their planktonic counterparts.     

Efficacy of denture cleansers on denture liners contaminated with Candida species

As poor denture hygiene is related to Candida colonisation, disinfectant solutions have been proposed as an effective method of preventing denture stomatitis. This study assessed the efficacy of denture cleansers on Candida albicans and Candida glabrata adherence on denture liners. Another aim was to correlate materials’ surface roughness (Ra) to Candida adherence. Specimens of three denture liners (soft and hard polymethyl methacrylate (PMMA)-based and soft silicone-based) were prepared and had their Ra measured. Specimens were randomly divided to adherence assays with C. albicans or C. glabrata. After contamination with the fungi, specimens were treated with an enzymatic cleanser solution, a cleanser solution or a 0.5% NaOCl solution by soaking for 3, 15 or 10 min, respectively. Control group specimens were soaked in distilled water for 15 min. Number of remaining Candida cells after treatment was determined by light microscopy (×400). Analysis of variance (α = 0.05) showed that Ra of the silicone-based liner was lower than that of the PMMA-based liners (p < 0.05). The overall results showed high C. glabrata adherence (p < 0.001), while the lowest levels of remaining Candida cells were found for the treatment with 0.5% NaOCl (p = 0.0019). No difference among denture cleansers and control was found (p = 0.19). There was no correlation between Ra and C. albicans or C. glabrata adherence in all materials tested. The only treatment able to reduce both Candida species adherence on all materials tested was 0.5% NaOCl solution.     

In vitro synergism between berberine and miconazole against planktonic and biofilm Candida cultures

Objectives

To investigate the antimycotic activity of the plant alkaloid berberine (BBR), alone and in combination with antifungal azoles, against planktonic and biofilm Candida cultures.

Design

The minimum inhibitory concentrations (MICs) of BBR, miconazole (MCZ), and fluconazole (FLC) towards Candida albicans, Candida glabrata, Candida kefyr, Candida krusei, Candida parapsilosis, and Candida tropicalis were determined by a microdilution method. For C. albicans, the synergistic effects of BBR combined with MCZ or FLC were examined in a paper disc agar diffusion assay and checkerboard microdilution assay. The effect of the BBR/MCZ combination was further investigated in a C. albicans biofilm formation model with a dual-chamber flow cell. The effect on metabolic activity of biofilm cells was established using 2,3-bis(2-methoxy-4-nitro-5-sulfophenyl)-2H-tetrazolium-5-carboxanilide (XTT)/menadione.

Results

Berberine inhibited the growth of various Candida species (MICs 0.98–31.25 mg/L) in the following order of susceptibility: C. krusei > C. kefyr > C. glabrata > C. tropicalis > C. parapsilosis and C. albicans. Synergism between BBR and MCZ or FLC was observed in the disc diffusion assay as well as in suspension showing an FIC index <0.5 (∑FIC = 0.19). Whilst neither BBR (16 mg/L) nor MCZ (0.8 mg/L) alone significantly inhibited biofilm formation of C. albicans, their combination reduced biofilm formation by >91% after 24 h, as established from the reduction in surface area coverage (P < 0.01). The BBR/MCZ combination also exhibited synergy against the metabolic activity of pre-formed C. albicans biofilms in polystyrene microtiter plates (∑FIC = 0.25).

Conclusion

Berberine exhibits synergistic effects with commonly used antimycotic drugs against C. albicans, either in planktonic or in biofilm growth phases.     

Antimicrobial activity of Bifidobacterium spp. isolated from healthy adult Koreans against cariogenic microflora

Objective

Dental caries is the main common infectious disease in the human oral cavity. Streptococcus mutans and Streptococcus sobrinus were reported to be the most important etiological factors in human dental caries. Thus, we examined the inhibitory effects of Bifidobacterium spp. cells and culture supernatants against S. mutans and S. sobrinus, including Streptococcus gordonii, and Aggregatibacter actinomycetemcomitans, which is associated with periodontal disease.

Methods

Mutans streptococci or A. actinomycetemcomitans and lactic acid bacteria (LAB) were mixed in 1:1 ratio and then incubated for 90 min at 37 °C. After the incubation, the viability of mutans streptococci or A. actinomycetemcomitans was determined by plate count technique. We also investigated the morphological changes of S. mutans treated with LAB using scanning electron microscopy (SEM).

Results

In vitro viability of S. mutans, S. sobrinus, S. gordonii, and A. actinomycetemcomitans was affected by human intestinal LAB identified as Bifidobacterium adolescentis SPM1005 and Bifidobacterium longum SPM1207. Especially, B. adolescentis SPM1005 cells at 1.0 × 10⁸ CFU had a strong growth-inhibiting effect against S. mutans and induced a 64% loss of its viability (p < 0.05). In addition, swollen and disrupted S. mutans were observed after incubation with B. adolescentis SPM1005. However, the culture supernatant of this strain did not show such inhibitory activity.

Conclusion

B. adolescentis SPM1005 cells decreased the growth of S. mutans, which is a risk factor for dental caries. Therefore, we suggest that this Bifidobacterium strain may be a useful probiotic microorganism for prevention of dental caries that does not have adverse effects.