口腔医院颌面外科患者细菌耐药监测分析

目的研究口腔医院颌面外科患者检出细菌的分布和耐药情况,为临床抗菌药物的选用和多重耐药菌的目标监测提供依据。 方法收集中山大学附属口腔医院2012年1月至2014年12月颌面外科感染患者检出的菌株,对检出病原菌的分布和耐药情况进行回顾性分析,各年份间耐药率的差异性应用卡方检验统计分析,P<0.05为差异有统计学意义。 结果共检出病原菌689株,革兰阳性菌占31.8%（219/689）,革兰阴性菌占68.2%（470/689）。检出总量排名前3位的病原菌为铜绿假单胞菌、肺炎克雷伯菌和草绿色链球菌,检出量分别为96、67和51株。3个年份所分离的铜绿假单胞菌对头孢二代、三代的耐药率低于10%,对限制级抗菌药物美洛培南（χ² = 2.675,P = 0.229）、氨曲南（χ² = 0.469,P = 0.791）的耐药率低于8%。3个年份分离的金黄色葡萄球菌对青霉素的耐药率分别为90.0%、66.7%、95.2%,均高于60%（χ² = 7.212,P = 0.024）。2012、2013年所分离的阴沟肠杆菌对四环素类、磺胺类、部分头孢菌素类的耐药率超过20%。 结论2012—2014年口腔医院颌面外科检出的铜绿假单胞菌和肺炎克雷伯菌数量最多,金黄色葡萄球菌和阴沟肠杆菌的耐药情况最为严重。应着重加强对铜绿假单胞菌和肺炎克雷伯菌的感染控制,重点监测金黄色葡萄球菌和阴沟肠杆菌的耐药情况。     

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...     

5种消毒方法对染菌口腔印模消毒效果的比较

目的：评价２％戊二醛浸泡、喷涂,５％艾力克浸泡、喷涂,臭氧柜处理对口腔印模和石膏模型上的表皮葡萄球菌、血液链球菌和枯草杆菌芽孢的消毒效果。方法：将无菌的印模和石膏模型平均分成３组,每组印模和石膏模型表面分别涂表皮葡萄球菌悬液、血液链球菌悬液和枯草杆菌芽孢菌悬液,并设立同期空白对照组。采用２％戊二醛浸泡、喷涂与５％艾力克浸泡、喷涂分别对染菌印模进行消毒处理。臭氧柜对石膏模型进行消毒处理。其后的不同时     

牙周病与肺感染相关性实验动物模型的建立

目的：建立牙周病与肺感染的实验动物模型，以排除临床各种干扰因素来探讨两者的关系。方法：通过钢丝结扎＋黏性高糖饮食法，建立不同程度的大鼠牙周病模型，各组均采用气管灌注（第2亚组）或口腔喂饲铜绿假单胞菌悬液（第3亚组）两种途径使大鼠肺脏感染，且设立不接触菌液的对照组（第1亚组）。观察不同牙周病程度及不同感染途径叠加后对牙周炎和肺炎的影响。结果：大鼠平均牙周袋深度及牙槽骨吸收总量：重度牙周病组（C组）〉轻度牙周病组（B组）〉牙周正常组（A组）。中性粒细胞分类百分数：各组中第2亚组〉第3亚组〉第1亚组；且C2组〉B2组与A2组，C3组〉B3组与A3组。25％的B3组大鼠及75％的C3组大鼠牙周袋内龈下菌斑中可检出铜绿假单胞菌。结论：钢丝结扎＋黏性高糖饮食法2周时可建立大鼠轻度牙周病模型，4周则可建立重度牙周病模型。经口腔喂饲铜绿假单胞菌可导致大鼠肺感染，但严重程度不如气管灌注途径。牙周炎症越重的大鼠深牙周袋内越易定植呼吸道致病菌，且合并的肺感染更为严重。     

牙科手机高压消毒的效果研究

目的 检测牙科手机的高压消毒效果。方法 分为高压蒸气消毒和紫外线消毒2组,每组的4个手机分别接种含1×10~9/ml浓度的金黄色葡萄球菌和变形链球菌菌悬液,经高压蒸气和紫外线分别消毒后的0min、30min、1h、2h、12h和24h分别采样,作细菌培养,记录CFU。结果 在高压蒸气消毒组,各检测时段均未培养出实验菌,而紫外线消毒组的牙科手机在检测的各个时段均有实验菌生长。结论 高压蒸气消毒对牙科手机的消毒效果是肯定的。     

次氯酸钠消毒口腔综合治疗台水路的效果评价

目的 评价口腔综合治疗台独立水源水路经525 mg/L次氯酸钠消毒前、后水样微生物种类和总菌落数的差异.方法 分别选择10台独立水源口腔综合治疗台为实验组和对照组.采集水路经525 mg/L次氯酸钠消毒前、后治疗台三用枪水样,计算总菌落数,定性检测水样中微生物种类与条件致病菌.利用SPSS 10.0统计软件进行两样本t检验、配对t检验和单因素方差分析,α=0.05.结果 (1)525 mg/L次氯酸钠消毒前、后口腔综合治疗台总菌落数几何均值分别为2.23×103和0 CFU/ml(P<0.05),差异有统计学意义;(2)消毒前、后微生物种类分别为8种和3种:消毒前检测出铜绿假单胞菌(检出率为36%),未检出大肠埃希氏菌和嗜肺军团菌;消毒后均未检出.结论 口腔综合治疗台水路存在微生物污染,并且包含条件致病菌铜绿假单胞菌,存在引起医患医院感染的潜在风险.525 mg/L次氯酸钠消毒剂对口腔综合治疗台水路具有良好消毒效果,能有效杀灭水样中微生物,可用于独立水源口腔综合治疗台水路的消毒处理.     

多孔HAPw/n-ZnO骨修复材料的抗菌机理及抗生物膜研究

目的:评估多孔羟基磷灰石晶须/纳米氧化锌(HAPw/n-ZnO)骨修复材料在抑制细菌生物膜中的作用,并探讨其抗菌机理。方法:分别建立金黄色葡萄球菌、变形链球菌、牙龈卟啉单胞菌生物膜体外模型。无光条件在相同的多孔HAPw/n-ZnO浓度梯度(0~2 g/L)下分别进行生物膜抑制试验与细胞内活性氧(ROS)检测,并利用扫描电子显微镜分析材料性能,未加入材料组作为对照。结果:无光条件下随着材料浓度递增,各浓度多孔HAPw/n-ZnO组(1.00、1.25、1.50、1.75、2.00 g/L)相对于对照组(0 g/L),3种细菌的生物膜形成量(A值)逐渐减少以及细胞内活性氧(ROS)水平(荧光强度)逐渐升高,差异有统计学意义(P＜0.05)。扫描电镜图片显示,复合材料组细菌黏附减少,生物膜形成受到抑制;细胞形态异常,细胞膜受损导致内容物泄露。结论:无光条件下多孔HAPw/n-ZnO材料对金黄色葡萄球菌、变形链球菌、牙龈卟啉单胞菌生物膜均有一定程度的抑制作用,其抗菌机理之一是活性氧(ROS)的形成。     

骨修复材料 HAPw／n-ZnO 抗感染效果的实验研究

目的：通过动物实验观察HAPw／n-ZnO在感染性骨缺损中的抗感染效果。方法：在24只SD大鼠（雌雄不限,220 g-250 g）左后肢股骨外侧髁处制备环状骨缺损,在缺损区置入金葡菌溶液（1×104CFU／mL,ATCC6538）,2周后随机分为两个实验组（n＝14）和一个空白组（n＝7）,对实验组骨缺损区行清创术后植入骨修复材料,空白组仅行清创术。于术后2周处死动物,进行组织切片及细菌学检查。结果：实验组对比空白对照组具有一定的抑菌抗感染的效果,其中HAPw／n-ZnO效果最为明显。结论：HAPw／n-ZnO能抑制金葡菌的生长,控制感染。     

纯中药口腔含漱液对皮肤黏膜的刺激性及杀菌作用

目的 观察纯中药口腔含漱液对皮肤、黏膜的刺激反应及对口腔常见细菌的杀菌效果。方法 分别用自制纯中药含漱液和生理盐水对14只5个月龄家兔滴左、右眼7 d;并涂抹10只7个月龄豚鼠左、右侧臀部、腹部、背部（涂药前脱毛）,左右对照,分别于涂抹后第3、7天各处死5只,制作病理切片。分别将金黄色葡萄球菌、大肠埃希氏菌、白念菌、铜绿假单胞菌、乙型链球菌制取的菌悬液加入含不同浓度纯中药含漱液或复方硼砂含漱液（朵贝尔 液）的营养液中,观察细菌的生长情况。分别将黏性放线菌、消化链球菌、核梭杆菌制取的菌液加入等2倍稀释的复方硼砂溶液和纯中药含漱液中,观察有无细菌生长。采用 SPSS17.0软件包对数据进行统计学分析。结果 家兔右眼结膜与对照组相比,无明显充血、发红等变化;豚鼠右侧臀部、腹部、背部皮肤与对照组相比,无明显红肿、皮炎等变化。纯中药含漱液对上述需氧菌和厌氧菌的杀菌效果均显著高于对照组。结论 纯中药含漱液对皮肤、黏膜无刺激反应,对口腔常见细菌有杀菌效果。     

内源性Farnesol对变异链球菌脱矿作用的研究

[摘要] 目的 观察内源性Farnesol处理变异链球菌后牙釉质脱矿的变化。方法 放置牙釉质切片于培养皿中,实验分5组,前3组加入变异链球菌菌悬液的同时分别添加去离子水、白色念珠菌24h上清、白色念珠菌菌悬液,第四组加入白色念珠菌菌悬液（实验组）,去离子水组为空白对照组。采用原子吸收分光光度法检测不同时间点（24、48、72h）菌悬液中钙离子的浓度。 结果 加入白色念珠菌24 h上清组钙离子的浓度在24、48、72h分别测得（80.26±1.63）、（81.14±1.24）、（78.31±0.76）μg/ml,明显低于其它变异链球菌组,实验组与对照组相比也有显著性差(P<0.05)。变异链球菌作用牙釉质的脱矿过程受到白色念珠菌分泌的Farnesol的调控,其脱矿作用受到明显的抑制。结论 内源性Farnesol可抑制变异链球菌对牙釉质的脱矿作用。     

Antimicrobial evaluation of calcium hydroxide in infected dentinal tubules.

The objective of this study was to evaluate the antimicrobial activity of calcium hydroxide in infected dentinal tubules. Four microorganisms, strains of ATCC (Streptococcus faecalis (ATCC-29212), Staphylococcus aureus (ATCC-6538), Bacillus subtilis (ATCC-6633), and Pseudomonas aeruginosa (ATCC-27853)) and one mixture of these were used. These strains were inoculated in brain heart infusion (BHI) and incubated at 37 degrees C for 24 h. Sixty-three human maxillary central incisors were prepared and sterilized by autoclaving. Five groups of 12 teeth each were contaminated for 28 days using new 24-h cultures every 72 h, prepared and adjusted to tube 2 of the MacFarland scale (6 x 10(8) cells/ml). Root canals were then irrigated with 5 ml of saline, dried, and completely filled with calcium hydroxide paste. At intervals of 0, 48, and 72 h, and 7 days, dressings were removed and teeth were immersed in 5 ml of BHI and incubated at 37 degrees C for 48 h to observe the growth and multiplication of the microorganisms. Three uninoculated teeth were maintained in a humid environment as an aseptic control. These teeth were immersed in BHI and maintained at 37 degrees C for 7 days to determine microbial growth. Bacterial growth was shown by turbidity of the culture medium and confirmed by seeding these broths on BHI agar at 37 degrees C for 24 h. The positive BHI tubes were selected, and inoculum was spread on the surface of BHI agar, followed by the same incubation conditions. Gram stain was conducted from BHI growth and from colonies growing on solid medium. Calcium hydroxide in infected dentinal tubules showed no antimicrobial effect on S. faecalis, S. aureus, B. subtilis, P. aeruginosa, or on the bacterial mixture used throughout the experiment.     

An analysis of the persistent presence of opportunistic pathogens on patient-derived dental impressions and gypsum casts

PURPOSE: This study aimed to assess the persistent presence of microorganisms on patient-derived dental impressions and gypsum casts, while highlighting important human pathogens such as Candida, methicillin-resistant Staphylococcus aureus (MRSA), and Pseudomonas aeruginosa. MATERIALS AND METHODS: The practices and opinions regarding cross-infection control from 59 general dentists in Japan were obtained via a questionnaire. Alginate impressions were made from 56 patients. Using a brain heart infusion agar medium, impression and imprint cultures were carried out to visualize the microbial contamination on the surfaces of the impressions and gypsum casts, respectively. The colonies on the surfaces of the 30 impression cultures and 26 imprint cultures were collected by swabbing and then inoculated onto selective agar plates to detect streptococci, staphylococci, Candida, MRSA, and P aeruginosa. RESULTS: The questionnaire showed that only 54% of general dentists had a cross-infection policy in their dental clinics, and only 30% to 40% were aware of the possible persistence of MRSA or P aeruginosa on impressions and gypsum casts. The impression/imprint cultures grew a large number of visible bacterial colonies on all of impression/gypsum cast samples investigated. Selective agar cultures demonstrated the presence of streptococci (100, 100%), staphylococci (56.7, 65.4%), Candida (30, 46.2%), MRSA (26.7, 15.4%), and P aeruginosa (6.7, 7.7%) on the impressions and the gypsum casts, respectively. CONCLUSIONS: This investigation showed that patient-derived dental impressions and gypsum casts are contaminated with numerous microbes, including Candida, MRSA, and P aeruginosa, which are known pathogens responsible for nosocomial and/or life-threatening infection in the immunocompromised host.     

口灵药膜的体外抑菌作用研究

目的：探讨口灵药膜的体外抑菌作用。方法：将金黄色葡萄球菌、大肠杆菌、绿脓杆菌均匀涂布于M-H琼脂平板培养基分别测定药膜主要活性成分的抑菌作用及药膜组方的最低抑菌浓度。结果：药膜组方对金黄色葡萄球菌有很好的抑菌作用,对大肠杆菌、绿脓杆菌有不同程度的抑菌作用。药膜组方的最低抑菌浓度为大肠杆菌6.250%、绿脓杆菌3.125%、金黄色葡萄球菌1.563%。结论：口灵药膜有抑制细菌的作用。     

In vitro evaluation of the antimicrobial activity of a castor oil-based irrigant.

The antimicrobial activity of irrigating solutions--Endoquil (castor oil detergent), 2% chlorhexidine gluconate solution, and 0.5% NaOCl solution-was evaluated against gram-positive cocci (Micrococcus luteus, Staphylococcus aureus, Enterococcus faecalis, Staphylococcus epidermidis, Streptococcus mutans, and Streptococcus sobrinus), gram-negative rods (Escherichia coli and Pseudomonas aeruginosa), and the yeast Candida albicans. Activity was evaluated using the two-layer agar diffusion technique. The base layer was obtained by pouring 10.0 ml of Muller Hinton Medium or 10.0 ml of Brain Heart Infusion agar in a Petri dish. After solidification a 5.0 ml seed layer of Muller Hinton Medium or Brain Heart Infusion agar with inoculum (106/ml) was added. Absorbent paper disks (6.0 mm in diameter) immersed in the solutions were placed at equidistant points. Plates were maintained at room temperature for 2 h for prediffusion of the solutions and incubated at 37 degrees C for 24 h. The candle jar system was used for the Brain Heart Infusion agar plates. All tests were performed in duplicate. After incubation the medium was optimized with 0.05 g% triphenyltetrazolium chlorate gel and inhibition halos were measured. All bacterial strains were inhibited by 2.0% chlorhexidine gluconate. Endoquil was effective against gram-positive microorganisms, and 0.5% NaOCl was effective only against S. aureus.     

Experimental bacteremia to demonstrate the barrier function of epithelium and connective tissue surrounding oral endosseous implants.

The barrier function of the peri-pillary epithelial-connective tissue cuff was experimentally tested with 12 endosseous metal blade vents in four beagles. An identified Staphylococcus aureus test strain was suspended in 0.5 ml saline. This bacterial suspension was then instilled into the sulcus of each implant. For stimulation of bacteremia the animals were fed with pelleted dry food. After 5 minutes, venous blood was drawn and incubated. After 72 hours of incubation none of the cultures showed bacterial growth of the test bacteria. In a second experiment 0.5 ml of the bacterial suspension was inoculated intravenously. After 1 h a bacteriological smear and peri-pillary tissue were taken. The specified Staphylococcus aureus was identified with phage typing in only on tissue specimen. This study demonstrates that the pseudo-attachment of the epithelial-connective tissue complex to the post of metal endosteal implants is functionable. Functionability, however, is endangered if biomechanical imbalance or infection occurs.     

Relationship between oral motor dysfunction and oral bacteria in bedridden elderly

OBJECTIVE: The purpose of this study was to analyze the relationship between oral bacterial colonization and oral motor dysfunction. STUDY DESIGN: Oral motor dysfunction (swallowing and speech disorders) and detection of oral bacterial species from dental plaque in 55 elderly persons who had remained hospitalized for more than 3 months were investigated and statistically analyzed. RESULTS: The detection rates of methicillin-resistant Staphylococcus aureus (MRSA), Pseudomonas aeruginosa, Streptococcus agalactiae, and Stenotrophomonas maltophilia were significantly higher in subjects with than in those without a swallowing disorder. A similar result was found with regard to the presence of a speech disorder. About half of subjects who had oral motor dysfunction and hypoalbuminemia had colonization by MRSA and/or Pseudomonas aeruginosa. CONCLUSION: These results suggest that the combination of oral motor dysfunction and hypoalbminemia elevated the risk of opportunistic microorganisms colonization in the oral cavity of elderly patients hospitalized over the long term.     

Evaluation of the antimicrobial effect of Er:YAG laser irradiation versus 1% sodium hypochlorite irrigation for root canal disinfection

This laboratory study evaluated Er:YAG laser antibacterial action in infected root canals. Forty-eight maxillary central incisors were used. After canal preparation, the teeth were autoclaved and divided into four groups: (1) non-treated teeth (control group); (2) teeth treated with NaOCl; (3) teeth irradiated with Er:YAG laser (7 Hz, 100 mJ, 80 pulses/canal, 11 sec) to the working length; (4) teeth irradiated similarly to, but 3 mm short, of the apex. The root canals from Groups 2, 3 and 4 were inoculated with 4 bacteria: Bacillus subtillus, Enterococcus faecalis, Pseudomonas aeruginosa, and Staphylococcus aureus, together with Candida albicans, and maintained for 24 h at 37 degrees C. All suspensions were adjusted to tube 2 of the MacFarland scale. The intracanal material was then collected with sterile paper points, which were placed in the canals for 5 min and then immersed in 5 ml of BHI medium. This was then seeded onto agar and stained by Gram's method. The NaOCl solutions and the Er:YAG laser irradiation to working length were effective against all five micro-organisms; however, 70% of the specimens irradiated 3 mm short of the apex remained infected.