The prevalence of A. actinomycetemcomitans, P. gingivalis and P. intermedia in selected subjects with periodontitis

Abstract. The present study was carried out in a private periodontal practice. 8 clinical criteria were chosen to select patients for microbiological examination. These criteria characterize prominent features of disease which at the start, during, or in the maintenance phase of treatment suggest difficulties in the progress of the periodontal therapy. Based on these clinical characteristics, an inventory was made of the prevalence of the 3 putative periodontal pathogens: Actinobacillus actinomycetemcomitans, Porphyromonas gingivalis, Prevotella intermedia. Out of 320 referred patients 91 patients did meet 1 of the clinical criteria and consequently were selected for microbiological examination. Results showed that young patients (19–30 years) with periodontitis demonstrated the presence of A. actinomycetemcomitans more often (69%: p (0.005) compared to older age cohorts. A. actinomycetemcomitans was found more often when localized breakdown (in particular in the 1 st molar and incisor region) was observed and in patient who responded poorly to scaling and rootplaning. P. gingivalis and P. intermedia were most frequently recovered in patients showing primarily a bone loss pattern of angular defects of 5 mm. Retrospectively, these patients were further categorized, based on full mouth radiographs, in (1) patients with primarily horizontal bone loss and (2) patients with primarily angular bony defects. Results showed that A. actinomycetemcomitans occurred less frequently in patients showing horizontal bone loss ( p (0.05).     

"Reverse" DMA hybridization method for the rapid identification of subgingival microorganisms

A "reverse" hybridization method is described, in which whole chromosomal DNA was extracted from 10-20 colonies of "unknown" strains in pure culture and labelled with digoxigenin by a random primer technique. DNA probes were prepared from a total of 23 strains and hybridized with targets containing 100 ng purified, denatured DNA from 38 reference strains fixed to nitrocellulose. 21/23 digoxigenin-labelled DNA probes successfully detected all members of the homologous species present on filters. Probes to Fusobacterium nucleatum strains 364 and MG detected 3/4 and 1/4 members of this species, respectively; 13/23 probes were 100% specific, but cross reactions between 10 probes and DNA targets from closely related, heterologous species occurred in 15/834 possible instances. False-positive reactions that occurred between closely related species were, however, easily distinguished and did not prevent the accurate identification of probe strains. Digoxigenin-labelled probes were capable of detecting 100 pg of homologous DNA. The reverse hybridization procedure allows identification or grouping of a large number of isolates within 3 days and provides a more economical means of characterizing subgingival isolates than predominant cultivable techniques and conventional phenotypic testing. This method could be adapted for the direct identification of microorganisms in subgingival plaque samples.     

Antimicrobial effect of radiation of ionized plasma

Department of Experimental Surgery, Interfaculty Laboratory Complex, and Department of Clinical Laboratory Diagnosis, Postgraduate Medical Faculty, N. I. Pirogov Second Moscow Medical Institute. (Presented by Academician of the Academy of Medical Sciences of the USSR V. V. Kupriyanov.) Translated from Byulleten' Éksperimental'noi Biologii i Meditsiny, Vol. 110, No. 10, pp. 413–145, October, 1990.     

Investigation of some antimicrobial procedures on the in vitro development of early murine embryos aimed toward developing methods for the disinfection of mammalian embryos prior to transfer

Eight-cell, zona pellucida-intact mouse embryos were exposed to the following substances or procedures that have been reported to have germicidal effects to determine if the embryos would survive and develop under in vitro conditions: the photosensitive substances hematoporphyrin, hematoporphyrin derivative, 8-methoxypsoralen, 4,5,8-trimethylpsoralen, and thiopyronine; the enzymes lipase (0.5%), phospholipase C (2 U/ml), chymotrypsin (0.5%), and trypsin (0.5%); pH 5.0; and helium/neon laser light, visible light, ultraviolet A light, and ultraviolet C light. Under the conditions used, embryos were not adversely affected by hematoporphyrin and/or helium/neon laser light; methoxypsoralen and/or ultraviolet A light; lipase; trypsin; pH 5.0 for 20 min; and visible light. Variable results were obtained from hematoporphyrin derivative with laser light. Thiopyronine, trimethylpsoralen in combination with ultraviolet A light, and ultraviolet C light killed embryos, and chymotrypsin and phospholipase C were harmful at 10- and 15-min exposure times, respectively.     

多黏菌素E治疗严重烧伤后多药耐药革兰阴性杆菌感染的临床评估

目的 评估多黏菌素E治疗严重烧伤患者多药耐药(MDR)革兰阴性杆菌感染的疗效及不良反应,为临床合理应用该抗生素提供依据.方法 选择笔者单位2005年8月-2009年1月收治的9例MDR革兰阴性杆菌感染烧伤患者,在药物敏感试验显示该感染菌种仅对多黏菌素E敏感或其他抗生素对其无效的前提下,采用多黏菌素E静脉滴注(100×10~4～150×10~4U/d)或静脉滴注联合呼吸道雾化吸入或灌洗(50×10~4～100×10~4U/d)给药.观察其细菌学疗效、临床疗效和不良反应(包括神经毒性和肾毒性,后者比较用药前后血清肌酐、尿素氮和胱抑素C水平).结果 9例患者中,7例为血流和肺部感染,1例血流、肺部和创面侵袭性感染,1例血流和尿路感染.病原菌主要为铜绿假单胞菌、鲍氏不动杆菌和嗜麦芽窄食单胞菌.9例患者应用多黏菌素E治疗后,血液中细菌清除率达92.3%;7例合并肺部感染患者,痰液MDR革兰阴性杆菌检出率从用药前的58.2%降至用药后的14.6%(P<0.01);1例合并尿路感染患者尿液中MDR革兰阴性杆菌得以清除.用药后,8例患者被判断为临床有效、1例为临床无效,有效率达88.9%.与用药前比较,9例患者用药后血清肌酐和尿素氮水平呈下降趋势;8例患者血清胱抑素C水平相近(P>0.05),1例患者明显升高但停药1个月后回降.用药期间和停药5 d内患者均未见神经毒性反应或其他不良反应.结论 在未出现更有效药物的前提下,合理应用多黏菌素E是目前治疗严重烧伤MDR革兰阴性杆菌感染的良好选择.     

口腔微生态与阻塞性睡眠呼吸暂停综合征相关性研究进展

近年来,睡眠呼吸障碍的高发病率及潜在风险被广泛关注。阻塞性睡眠呼吸暂停综合征(OSAS)作为各年龄段最常见的睡眠呼吸障碍,已严重威胁到人类健康。口腔微生态作为“人类微生物组计划”的重要组成部分,其生物群落结构、功能与OSAS及其合并症的发生发展密切相关。本文就口腔微生态与OSAS的相关研究展开综述,为临床深入研究提供参考。     

1株海洋来源真菌Aspergillus alabamensis次级代谢产物研究

目的对来源于西沙群岛的海绵(Agelas sp.)共附生微生物Aspergillus alabamensis(18-xs-01-zp-3)进行菌种鉴定及次级代谢产物的研究。方法通过分子生物学方法鉴定菌株种属;综合运用硅胶柱层析、薄层色谱和半制备高效液相色谱(HPLC)等色谱学方法对次级代谢产物进行分离纯化,通过核磁共振(NMR)、质谱(MS)等现代波谱学方法并结合文献对所得化合物进行结构鉴定。结果从中分离得到7个单体化合物,分别是ardeemin型生物碱3个:5-N-acetyl-15bβ-hydroxyardeemin(1)、5-N-acetylardeemin(2)、5-N-acetyl-15b-didehydroardeemin(3);二酮哌嗪生物碱2个:3-benzylidene-3, 4-dihydro-4-methyl-lH-l, 4-benzodiazepine-2, 5-dione(4)、benzodiazepinedione(5);吲哚类生物碱2个:luteoride E(6)、14-hydroxyterezine D(7)。结论从该菌株共分离得到7个生物碱类化合物,...     

石莼、网地藻多糖含量与藻际微生物丰度关系研究

目的：研究石莼、网地藻藻际微生物丰度对多糖含量的影响。方法：通过实时荧光定量PCR(Real-time PCR)技术对石莼、网地藻所附着的藻际微生物丰度进行研究(细菌16S rDNA以及真菌18S rDNA丰度)。结果：石莼多糖含量、藻际微生物总DNA含量均显著高于网地藻(p <0.05)。石莼藻际微生物丰度(细菌1.04×1010-1.42×1010拷贝数/g干样,真菌1.01×107-1.38×107拷贝数/g干样) 显著高于网地藻(细菌2.05×108-6.9×108拷贝数/g干样、真菌2.59×105-4.79×105拷贝数/g干样)(p<0.01)。典型对应分析(CCA分析)表明石莼、网地藻多糖含量与藻际微生物(细菌、真菌)丰度显著相关。结论：石莼、网地藻藻际微生物丰度对多糖含量有一定影响。     

海洋微生物抗菌活性的初步研究

从南海、东海、黄海等海域的海洋底质、生物样品中分离到1003个海洋微生物菌株．包括520株放线菌、111株真菌、222株常温细菌和150株耐热细菌。通过纸片法对其抗菌活性进行筛选．结果发现321株海洋微生物具有抑菌活性,占总分离菌株的32．0％。放线菌、真菌、常温细菌、耐热细菌的活性菌株比例分别为39．6％,32．4％。17．1％,27．3％。具有抑菌活性的菌株比例与样品来源密切相关。生物样品来源的细菌抑菌活性较高的菌株比例较底质样品来源的要高,而海洋放线菌与海洋真菌结果相反。各类海洋微生物菌株的抗菌谱有很大的不同。     

DNA提取方法进展

DNA的提取是分子生物学研究的基础技术,提取的DNA的纯度及结构完整性是进行基因工程各项研究所必需的条件。近年来一些新的或改进的DNA提取纯化方法不断出现,本文对从陆生动物、植物、微生物以及海洋生物提取DNA的方法进行综述。