采用PCR方法鉴别伴放线放线杆菌的6种血清型

目的：探索采用PCR的方法对伴放线放线杆菌的不同菌株进行血清型分类。方法：根据伴放线放线杆菌不同血清型特异性多糖抗原基因序列设计6对不同的寡核苷酸引物，用这6对引物分别对所选择伴放线放线杆菌6种不同的血清型菌株各3株，共18株，其中参考菌株6株，系ATCC29523（血清型a），ATCC43718（血清型b），ATCC33384（血清型c），IDH781（血清型d），IDH1705（血清型e）以及CU1000（血清型f），其余12个菌株均为临床分离株的DNA进行PCR扩增分析。结果：每一对引物均针对相应的血清型产生特异性单一条带PCR产物，产物大小分别为428bp（a），298bp（b），559bp（c），690bp（d），211bp（e），232bp（f）。全部18个菌株均能够被准确识别，无交叉反应。结论：PCR方法可以快速准确地鉴别伴放线放线杆菌目前已知的全部6种血清型。     

放线共生放线杆菌与牙周疾病

放线共生放线杆菌(Actinobacillus actinomycetemcomitans,Aa)是牙周主要致病菌之一,近年对其研究较多,并取得不少进展,本文着重描述了放线共生放线杆菌的一些重要特性,包括其传播特征、分类、毒性特征、检测方法、与牙周炎的关系及对临床治疗的指导作用。     

放线共生放线杆菌与牙周疾病

放线共生放线杆菌（Actinobacillus actinomycetemcomitans,Aa)是牙周主要致病菌之一，近年对其研究较多，并取得不少进展，本着文重描述了放线共生放线杆菌的一些重要特性，包括其传播特征，分类，毒性特征，检测方法，与牙周炎的关系及对临床治疗的指导作用。     

放线共生放线杆菌表面相关物质对Mc3T3—E1细胞的增殖？…

目的：观察放线共生放线杆菌表面相关物质成对骨样细胞Ｍｃ３Ｔ３－Ｅ１的增殖抑制作用。方法：采用细胞计数法和图像分析法观察。结果：此物质抑制作用明显，能抑制分裂，增殖，使细胞，细胞核面积增大，１００μｇ／ｍｌ与对照组差别显著（Ｐ〈０．０５），且细胞无死亡现象。结论：此物质可明显抑制成骨样细胞Ｍｃ３Ｔ３－Ｅ１的生长，增殖，在骨缺失过程中起重要的作用。     

放线共生放线杆菌的分型和基因鉴定方法

放线共生放线杆菌（Ａｃｔｉｎｏｂａｃｉｌｕｓａｃｔｉｎｏｍｙｃｅｔｅｍｃｏｍｉｔａｎｓ,Ａａ）是革兰氏阴性、兼性厌氧的球杆菌,它在牙周炎患者的牙周袋中检出率较高,有报告９０％‘以上青少年牙周炎的牙周损害部位有此菌定居［１］,因此,被认为是与牙周炎,...     

伴放线放线杆菌血清型分析

目的 PCR法检测伴放线放线杆菌（Actinobacillus actinomy＇etemcomitans，Aa）临床分离菌株血清型，分析其与flp-1基因型的关系。方法用血清型特异性引物，通过普通PCR和多重PCR的方法对60株Aa临床分离菌株的血清型进行鉴定，并分析其与flp-1基因型的关系。结果 60株Aa临床分离菌株中血清型c型63，33％，e型23．33％，b型6.67％，a，f型各占3．33％，未检测到d型菌株；在24名被检测者中，15名检测到c型An菌株，3名检测到b型菌株，各有2名分别检测到a、e、f型菌株。fip-1基因型Ⅰ型菌株的血清型均为a型，40株Ⅱ型菌株中38株为c型，Ⅳ型菌株均为b型，11株Ⅴ型菌株中9株为e型，Ⅵ型菌株均为e型。结论 Aa血清型分布以c型为主，fip-1基因型与菌株血清型存在一定对应关系。     

口腔放线共生放线杆菌

放线共生放线杆菌(Actinobacillus actinomycetem—comitans,A.a)是一兼性厌氧、嗜CO_2、无动力的G-小杆菌。正常以少量寄居于口腔牙菌斑,现归于嗜血杆菌属。但其分类问题还有争论。最近的研究表明,A.a的感染不仅与青少年牙周炎(juvenile periodontitis-JP)的关系密切,而且在快速进行性牙周炎(rapidly progressive periodontitis-RP)和活跃性成人牙周炎(adult periodontitis—AP)中也占有一定地位。提示了A.a与牙周炎的活动性和进行性破坏有关。本文仅就A.a的生物学性状及致病性和免疫性作一综述。一、生物学性状 (一)形态与染色为G-小杆菌,有的略弯     

放线共生放线杆菌表面相关物质对人牙龈成纤维细胞超微结构的影响

目的：观察放线共生放线杆菌对人牙龈成纤维细胞超微结构的影响。方法：１００ｍｇ／Ｌ细菌表面相关物质和人牙龈成纤维细胞在ＣＯ２孵箱内培养７２ｈ后,采用透射电镜观察细菌表面相关物质对成纤维细胞超微结构的影响。结果：主要使细胞粗面内质网扩张,线粒体水肿,溶酶体增多,但未见膜性结构有明显破坏现象。结论：此物质可影响细胞的超微结构,但不致细胞死亡     

放线共生放线杆菌与青少年牙周炎

最近几年来,特异性细菌感染在牙周病病因学中的作用日益受到重视,目前对于青少年牙周炎(juvenile Periodontitis-JP)与牙周菌丛之间的关系有了许多新的认识。大量证据表明青少年牙周炎,特别是局部型青少年牙周炎(LJP)与牙周放线共生放线杆     

Clonal distribution of natural competence in Actinobacillus actinomycetemcomitans

The competence for natural transformation was investigated in 67 Actinobacillus actinomycetemcomitans strains. The transformation assays were performed with both cloned DNA fragments and chromosomal markers of A. actinomycetemcomitans. Competence was found in 12 of 18 serotype a strains, 0 of 21 serotype b strains, 0 of 14 serotype c strains, 3 of 6 serotype d strains, 3 of 4 serotype e strains, 0 of 3 serotype f strains, and 0 of 1 nonserotypeable strain. The transformation frequencies varied from 5 x 10(-3) to 4 x 10(-6) (median 1.5 x 10(-4)). The distribution pattern of natural competence is concordant with the major clonal lineages of A. actinomycetemcomitans. Serotype a strains are predominantly competent for transformation, while serotypes b and c strains are apparently non-competent.     

Absence of an especially toxic clone among isolates of Actinobacillus actinomycetemcomitans recovered from army recruits

Actinobacillus actinomycetemcomitans is a major periodontal pathogen which is associated with early-onset and adult periodontitis. The organism has been shown to be widely distributed among dentate, healthy individuals as well. It has been demonstrated that A. actinomycetemcomitans shows great genetic diversity. An especially virulent clone of the organism (JP2-like) with a specific 530-base pair (bp) deletion in the promoter region of the leukotoxin gene has been isolated from localized juvenile periodontitis patients and related subjects of African and African-American origin. The aim of the present study was to examine the presence of this specific clone employing specific oligonucleotide primers in a polymerase chain reaction among 51 isolates of A. actinomycetemcomitans recovered from 201, 18- to 25-year-old recruits with no or minor periodontal disease. In addition, clinical isolates from 37 periodontitis patients were analyzed as well as reference strains ATCC 29524, NCTC 9710, Y4 and JP2. Primers amplifying a specific 285-bp amplification product in the ltxA region of the leukotoxin gene and a specific 547-bp amplification product of 16 S rRNA were used to genetically confirm identification of the organisms. Primers amplifying sequences in the leukotoxin promoter region were used to identify the deletion. Species specific primers definitively identified all A. actinomycetemcomitans isolates. No isolates from army recruits or the reference strains displayed the deletion in the leukotoxin promoter region. However, in the periodontitis group, a 24-year-old individual from Ghana with localized juvenile periodontitis was identified with an intraoral infection with highly toxic A. actinomycetemcomitans (JP2-like). Present results confirm previous observations of absence of a highly toxic clone of A. actinomycetemcomitans among periodontally healthy and diseased Caucasians as well as a possible presence in localized juvenile periodontitis in individuals of African origin. Received: 31 August 1998 / Accepted: 3 August 1999     

The capability of Actinobacillus actinomycetemcomitans, Bacteroides gingivalis and Bacteroides intermedius to indicate progressive periodontitis; a retrospective study

This study evaluated the statistical association of Actinobacillus actinomycetemcomitans, Bacteroides gingivalis and Bacteroides intermedius with progressive periodontitis. 146 adults with a history of advanced periodontitis contributed 105 "nonprogressing" and 130 "progressing" periodontal sites. Periodontal disease activity was assessed by radiographic changes in crestal alveolar bone level. The subgingival proportion of the 3 test bacteria was determined by selective and nonselective culturing. The relationship between bacterial proportions and disease progression was evaluated using subgrouping and multiple-regression analyses. All 3 test bacteria had to be considered in order to distinguish nonprogressing and progressing periodontitis with a reasonably high sensitivity. A recovery rate below 0.01% for A. actinomycetemcomitans, 0.1% for B. gingivalis and 2.5% for B. intermedius defined a site with nonprogressing disease with 87% sensitivity and 84% specificity. By utilizing transformed values of the bacterial recovery rates and optimal test criteria determined by multiple regression analysis, it was possible to obtain sensitivities between 83% and 95% and specificities between 86% and 69%. These 3 bacterial species might serve as valuable components of a periodontitis activity test based on microbiological variables.     

Actinobacillus actinomycetemcomitans in human periodontal disease

Recent evidence implicates Actinobacillus actinomycetemcomitans in the etiology of localized juvenile periodontitis. This paper reviews the morphological, biochemical and serological charcteristics of A. actinomycetemcomitans, evidence incriminating it as a periodontopathogen, its importance in human nonoral infections, and virulence factors which may be involved in the pathogenesis of A. actinomycetemcomitans infections. A. actinomycetemcomitans is a non-motile, gram-negative, capnophilic, fermentative coccobacillus which closely resembles several Haemophilus species but which does not require X or V growth factors. The organism has been categorized into 10 biotypes based on the variable fermentation of dextrin, maltose, mannitol, and xylose and into 3 serotypes on the basis of heat stable, cell surface antigens. A. actinomycetemcomitans' primary human ecologic niche is the oral cavity. It is found in dental plaque, in periodontal pockets, and buccal mucosa in up to 36% of the normal population. The organism can apparently seed from these sites to cause severe infections throughout the human body such as brain abscesses and endocarditis. There is a large body of evidence which implicates A. actinomycetemcomitans as an important micro-organism in the etiology of localized juvenile periodontitis including: (1) an increased prevalence of the organism in almost all localized juvenile periodontitis patients and their families compared to other patient groups; (2) the observation that localized juvenile periodontitis patients exhibit elevated antibody levels to A. actinomycetemcomitans in serum, saliva and gingival crevicular fluid; (3) the finding that localized juvenile periodontitis can be successfully treated by eliminating A. actinomycetemcomitans from periodontal pockets; (4) histopathologic investigations showing that A. actinomycetemcomitans invades the gingival connective tissue in localized juvenile periodontitis lesions; (5) the demonstration of several pathogenic products from A. actinomycetemcomitans including factors which may: (a) facilitate its adherence to mucosal surfaces such as capsular polysaccharides; (b) inhibit host defense mechanisms including leukotoxin, a polymorphonuclear leukocyte chemotaxis inhibiting factor, and a lymphocyte suppressing factor (c) cause tissue destruction such as lipopolysaccharide endotoxin, a bone resorption-inducing toxin, acid and alkaline phosphatases, collagenase, a fibroblast inhibiting factor and an epitheliotoxin.(ABSTRACT TRUNCATED AT 400 WORDS)     

The distribution of Actinobacillus actinomycetemcomitans in human plaque

The association between Actinobacillus actinomycetemcomitans and periodontal disease in juveniles has been well documented. The purpose of this investigation was to determine the prevalence and proportions of A. actinomycetemcomitans in supragingival and subgingival plaque samples from the maxillary first molars of a large number of young adults. The study population included 284 adults, aged 20–40, ranging in periodontal disease status from healthy to moderate periodontitis but with the majority exhibiting early periodontal disease. The clinical characteristics of probing depth, attachment level, plaque index, and gingival index were measured. Supragingival and subgingival plaque samples were evaluated microscopically for microbial forms. They were also cultured on supplemented blood agar and various selective agar media including selective media for A. actinomycetemcomitans. The prevalence of A. actinomycetemcomitans in subgingival and supragingival plaque for individuals in the population was 13.0% (37/284) and 4.9% (14/284), respectively. Proportions of actinobacilli, based on total anaerobic counts, were found at or below 1% in 87% of 47 subgingival sites from 37 subjects. Supragingival and subgingival sites with actinobacilli were compared to sites without actinobacilli. Subgingival sites with A. actinomycetemcomitans had a significantly higher mean plaque index, with 79% of these sites having a plaque index greater than 1.0 compared to 30% of sites without actinobacilli. The mean gingival index, probing depth, and attachment level of sites with actinobacilli were also higher, but not significantly, than those without. Of the microbial forms enumerated, only spirochetes had a significantly higher mean proportion at subgingival sites when compared to sites without actinobacilli. Mean proportions of the cultivable microorganisms, Veillonella spp. and Streptococcus spp., were significantly lower at sites with A. actinomycetemcomitans. Differences in the mean proportions of certain microorganisms were compared between the 47 subgingival sites with actinobacilli divided into three groups by probing depth. Mean proportions of A. actinomycetemcomitans were significantly higher at intermediate probing depths between 3.0 and 5.0 mm compared to deeper sites with probing depths above 5.0 mm. On the other hand, dark-pigmented Bacteroides spp. mean proportions were significantly higher at deeper probing depths than at either intermediate or shallow, less than or equal to 3.0 mm, probing depths. There were no significant differences in the mean proportions of spirochetes between shallow, intermediate, or deeper probing depths of the 47 subgingival sites with actinobacilli.     

Natural distribution of oral Actinobacillus actinomycetemcomitans in young men with minimal periodontal disease

A total of 1005 subgingival and extracrevicular samples from 201 male recruits, 18–25 yr old, were selectively cultivated for Actinobacillus actinomycetemcomitans. The organism was isolated in 55 subjects (27%); 9.5% of pooled subgingival plaque samples from first molars, 14% cheek mucosa, 20% dorsum of tongue and 20% saliva samples were culture-positive. In order to divide the study population into distinct clinical categories, cluster analysis was performed, based on previous caries experience, probing pocket depth categories, bleeding scores, visible plaque and calculus. Two clusters (n=86 and n=92, respectively) were identified with no or minimal periodontal disease (mean±standard deviation % of periodontal probing depth 1–2 mm 78.7±10.4% and 57.4±12.6%, respectively; virtually no periodontal probing/depth in excess of 4 mm) and a relatively low DMF-S (22±13). A third cluster (n=22) had, in contrast, a high DMF-S (47.7±173) and a relatively high % of periodontal pockets of ≥5 mm (5.9 ±5.2%). Prevalence of A. actinomycetemcomitans in this cluster was 41%, while the organism was found in 23% and 27% in the minimally diseased populations (p<0.15). Whereas no heterogeneity of associations between subgingival and extracrevicular occurrence of the organism could be ascertained in different clusters, the organism was significantly more often identified in extracrevicular material, especially dorsum of tongue samples, compared with subgingival plaque (McNemar's X²=12.45, p<0.001). Multiple linear regression analysis revealed the number of A. actino-mycetemcomitans positive samples as well as the % of sites bleeding on probing being positively associated with the % of sites with a probing pocket depth of ≥5 mm (R2=0.345, p≤0.0001). The present large-scale investigation points to the wide distribution of this putative periodontopathogen in young individuals with minimal periodontal disease.     

Actinobacillus actinomycetemcomitans fimbriae

Freshly isolated Actinobacillus actinomycetemcomitans strains were found to possess fimbriae. These appendages appeared to be irreversibly lost after 30 to 40 subcultures in the laboratory. The fimbriated strains were associated with a specific type of colonial morphology designated SP (Star Positive); the non-fimbriated variant colony was designated SN (Star Negative). The fimbriae were approximately 5 nm wide and could be several μm in length. The fimbriated cells tended to aggregate readily whereas the non-fimbriated cells formed uniform suspensions. Three stains of fimbriated A. actinomycetemcomitans isolated from different patients were compared to their non-fimbriated variants for attachment to hydroxyapatite (HA) and saliva coated hydroxyapatite (SHA). Two of the fimbriated variants exhibited a 3- to 4-fold enhancement of attachment to HA and SHA over their non-fimbriated variant. However, there did not appear to be any specificity for SHA over HA. One strain (Pag) showed no major differences in attachment of the fimbriated or non-fimbriated variant, albeit the fimbriae were indistinguishable from those of the other A. actinomycetemcomitans strains. Thus, there may be molecular differences among fimbriae of various A. actinomycetemcomitans strains which determine both their tissue specificity and their affinity for particular substrates.     

Fimbriation of Actinobacillus actinomycetemcomitans

Presence of fimbriae on a bacterium may promote its initial colonization, survival and ability of tissue penetration. Thus, electron microscopy was performed on negatively stained periodontal Actinobacullus actinomycetemcomitans from a patient with Papillon-Lefevre syndrome. The isolates were, in contrast to reference strains found to carry a considerable amount of fimbriae (5 nm in diameter). The presence of fimbriae may support the hypothesis of the invasive ability of this bacterium.     

Actinobacillus actinomycetemcomitans recovery from extracrevicular locations of the mouth

Associations between recovery of Actinobacillus actinomycetemcomitans from samples of subgingival plaque, and samples of buccal mucosa, tongue and unstimulated saliva were studied in 107 subjects. Ten subjects had gingivitis, 18 localized juvenile periodontitis, 45 rapidly progressive periodontitis and 32 adult periodontitis. Two children suffered from prepubertal periodontitis. Heterogeneity tests for associations in different study populations yielded nonsignificant results. Mantel-Haenszel's common odds ratios were 52.9, 37.2 and 19.8 for respective associations between pooled subgingival samples, and cheek, saliva and tongue samples. Significant McNemar's chi-square of 5.88, 11.25 and 16.96 for respective associations pointed to secondary occurrence of A. actinomycetemcomitans in extra-crevicular samples. Multiple linear regression yielded a significant influence of the number of deep periodontal pockets of 7 mm or more and a negative influence of the diagnosis "adult periodontitis" on the log-transformed number of colony-forming units of A. actinomycetemcomitans in samples from cheek mucosa in patients infected with the organism. Extracrevicular occurrence of A. actinomycetemcomitans seems to reflect total subgingival numbers of the organism. Especially sampling check mucosa appears to be a promising tool in the diagnosis of a periodontal infection with A. actinomycetemcomitans .