江西省表观健康猪群携带猪链球菌状况分析

目的：了解江西省表观健康猪群携带猪链球菌的情况,为有效防控猪链球菌病提供科学依据。方法选取景德镇市、崇仁县为采样点,采集表观健康猪群鼻咽拭子和扁桃体进行猪链球菌病原分离鉴定。结果共采集表观健康猪群鼻咽拭子和扁桃体样本301份,检出2株猪链球菌2型,其毒力基因mrp、sly、ef均为阴性。结论本次调查中江西省表观健康猪携带猪链球菌的带菌率为0.66％。     

Correlation of Streptococcus mutans and Streptococcus sanguinis colonization and ex vivo hydrogen peroxide production in carious lesion-free and high caries adults

Objective

This study was conducted to estimate oral colonization by Streptococcus mutans and Streptococcus sanguinis in adults with high and without any caries experience. Furthermore, differences in the amount of hydrogen peroxide (H₂O₂) produced by S. sanguinis isolated from both groups were assessed.

Design

Forty adults were divided into: (i) carious lesion-free, without any carious lesion, assessed by the International Caries Detection and Assessment System (ICDAS), or restoration, (CF) and (ii) high caries experience (HC). Saliva samples were collected and seeded on respective agar-plates for enumeration of total streptococci, S. mutans and S. sanguinis (CFU/mL) and compared between groups. Additionally, S. sanguinis colonies obtained from both groups were inoculated on Prussian blue agar for H₂O₂ detection. Production of H₂O₂ was quantified and compared between the two groups. S. sanguinis counts were significantly higher in CF than HC individuals (p < 0.05). Conversely, S. mutans showed significantly higher levels in HC than CF subjects (p < 0.001). S. sanguinis colonies from CF individuals produced significantly larger H₂O₂ halos compared with HC subjects.

Conclusions

S. sanguinis predominates over S. mutans in saliva of adults without caries experience. In those people, S. sanguinis produces more H₂O₂ex vivo.     

新生儿无乳链球菌感染的危险因素及药敏分析

目的分析新生儿感染无乳链球菌的危险因素及药物敏感性,为预防和治疗新生儿无乳链球菌感染提供依据。方法收集2013年1~12月1 200份临床送检的新生儿血液、胃液、脓液标本,以及相应母体泌尿生殖道标本进行细菌培养与药敏试验,并回顾性分析患儿疾病类型、母体感染状况、分娩方式、孕晚期用药情况、新生儿死亡情况等临床资料。结果共80例新生儿感染无乳链球菌,其中败血症、脐炎、早产、宫内感染、吸入性肺炎患儿分别占8.75%、10.00%、15.00%、22.50%、43.75%;其母体生殖道标本无乳链球菌阳性率达51.25%,且细菌药敏结果与患儿一致;患儿以自然分娩为主,共71例(88.75%),仅9例(11.25%)为剖宫产。80株无乳链球菌对万古霉素、利奈唑胺、青霉素和头孢曲松的敏感率均为100.00%,对红霉素、克林霉素、左氧氟沙星的耐药率较高,分别为77.50%、57.50%、33.75%。结论母体带菌与分娩方式可能是新生儿无乳链球菌感染的重要危险因素,产科医生应重视对围产期孕妇无乳链球菌的常规筛查,实验室应提高对无乳链球菌的检测能力并及时提供药敏检测结果,为临床合理用药提供重要依据。     

Enterococcal endocarditis: 107 cases from the international collaboration on endocarditis merged database

PURPOSE: To describe clinical features and outcomes of enterococcal left-sided native valve endocarditis and to compare it to endocarditis caused by other pathogens. SUBJECTS AND METHODS: Patients in the International Collaboration on Endocarditis-Merged Database were included if they had left-sided native valve endocarditis. Demographic characteristics, clinical features, and outcomes were analyzed. Multivariable analysis evaluated enterococcus as a predictor of mortality. RESULTS: Of 1285 patients with left-sided native valve endocarditis, 107 had enterococcal endocarditis. Enterococcal endocarditis was most frequently seen in elderly men, frequently involved the aortic valve, tended to produce heart failure rather than embolic events, and had relatively low short-term mortality. Compared to patients with non-enterococcal endocarditis, patients with enterococcal endocarditis had similar rates of nosocomial acquisition, heart failure, embolization, surgery, and mortality. Compared to patients with streptococcal endocarditis, patients with enterococcal endocarditis were more likely to be nosocomially acquired (9 of 59 [15%] vs 2 of 400 [1%]; P <.0001) and have heart failure (49 of 107 [46%] vs 234 of 666 [35%]; P = 0.03). Compared to patients with S. aureus endocarditis, patients with enterococcal endocarditis were less likely to embolize (28 of 107 [26%] vs 155 of 314 [49%]; P <.0001) and less likely to die (12 of 107 [11%] vs 83 of 313 [27%]; P = 0.001). Multivariable analysis of all patients with left-sided native valve endocarditis showed that enterococcal endocarditis was associated with lower mortality (odds ratio [OR] 0.49; 95% confidence interval [CI] 0.24 to 0.97). CONCLUSIONS: Enterococcal native valve endocarditis has a distinctive clinical picture with a good prognosis.     

Influence of the magnetic field on microorganisms in the oral cavity

Since the beginning of their lives, all living organisms are exposed to the influence of geomagnetic fields.

Objectives

: With respect to the positive effects that magnetic fields have on human tissues, especially the bactericidal effect, this investigation aimed to assess their influence on the reduction of oral microorganisms.

Material and Methods

: In order to obtain adequate specimens of dental plaque deposit, microbes such as Streptococcus parasanguinis, Staphylococcus epidermidis, Rhodococcus equi and Candida albicans were isolated from the human mouth. To establish the intensity of microbial growth on the basis of the modified optical density (OD) of agar turbidimetry assay, microbial count and spectrophotometry were applied. The study was carried out with two microbial concentrations (1 and 10 CFU/ml) after periods of incubation of 24 and 48 h and using micromagnets.

Results

: A positive effect of the magnetic field, resulting in the reduction of dental plaque microbes in vitro, was found. In the first 24 hours of exposure to the magnetic field, the number of all isolated microbes was significantly reduced. The most potent influence of magnets and the most intensified reduction after 24 hours were evident in Candida albicans colonies. The decrease in the influence of magnets on microbes in vitro was also detected.

Conclusions

: Magnets reduce the number of microbes and might be recommended as a supplement in therapy for reduced periodontal tissues. This is important because periodontal tissues that are in good conditions provide prolonged support to the oral tissues under partial and supradental denture.     

胶原层粘连结合蛋白的结构和功能及防治策略

变异链球菌既与龋病关系密切,亦与感染性心内膜炎和动脉粥样硬化等病变密切相关,其表面的胶原层粘连结合蛋白（Cnm）具有结合胶原蛋白和层粘连蛋白的能力。Cnm蛋白分子中编号152~316基团的165个氨基酸序列跟胶原结合蛋白的胶原结构域高度相似,与金黄色葡萄球菌、粪肠球菌和马链球菌胶原结合蛋白具有高度的同源性。Cnm蛋白存在于变异链球菌中,介导细菌与细胞外基质的结合和在宿主细胞内的侵袭;此外,CnaB和CbpA蛋白也可能在结合细胞外基质和侵袭宿主细胞方面起着重要的作用。研究者们认为：一方面可将Cnm蛋白作为生物标志物以筛选患者,从而判断是否需要接受预防性治疗;另一方面也可将Cnm蛋白作为治疗变异链球菌感染的目标;但是,目前的研究尚未发现能抑制cnm基因或Cnm蛋白的有效药物,还需进一步研究。有关Cnm蛋白的研究,对于人工干预变异链球菌黏附力、聚集及其生物膜形成,对于龋病和其他全身系统疾病尤其是心内膜炎等疾病的防治具有重要的意义。