Assignment of Actinomyces pyogenes-like (CDC coryneform group E) bacteria to the genus Actinomyces as Actinomyces radingae sp. nov. and Actinomyces turicensis sp. nov.

In a previous study the authors reported the characterization of some facultatively anaerobic, Gram-positive, non-sporeforming rods which were found in mixed cultures from various infectious processes, including patients with otitis, empyema, perianal abscesses and decubitus ulcers. Phenotypically these organisms closely resembled Actinomyces pyogenes although their precise taxonomic position remained unknown. In the present investigation the authors have determined the 16S rRNA gene sequences of some representative strains of the Actinomyces pyogenes -like bacteria and report the results of a comparative sequence analysis. On the basis of the results of the present and earlier findings two new Actinomyces species, Actinomyces radingae sp. nov. and Actinomyces turicensis sp. nov. are proposed. The type strains are DSM 9169^T and DSM 9168^T, respectively.     

Effect of metabolic substances of oral Actinomyces on Candida albicans

Actinomyces naeslundii, Actinomyces viscosus and Candida albicans are associated with root cavity. The aim of this study was to determine, in vitro, the effect produced by the metabolic substances elaborated by Actinomyces naeslundii and Actinomyces viscosus on Candida albicans. The strains were isolated of saliva. There were used the double plaque diffusion method (DPDM) and the method of radial diffusion (MRD). The effect of the time of incubation and of different concentrations of metabolic substances elaborated by Actinomyces naeslundii and Actinomyces viscosus on the kinetics of growth of C. albicans were studied. Later, the nature of the substances produced by the two strains of Actinomyces was determined. It was found that there was no inhibition of the growth of C. albicans by A. naeslundii and A. viscosus in the DPDM and the MRD. There was stimulation of the growth of C. albicans by the two strains of Actinomyces when the DPDM was used. In the MRD the results were negative. Metabolic substances produced by both species stimulated the growth of C. albicans in low concentrations but at high concentrations inhibition was observed. The best concentration of the stimulating factor, a protein substance stable to 70 degrees C, corresponds to a dilution of 1/80. The inhibition of the growth of C. albicans was produced by the decrease of the pH, the higher effect being obtained with the dilution 1/5. The metabolic substances produced by A. naeslundii and A. viscosus can have both inhibitory and stimulant effects on C. albicans, according to their concentration. These metabolic interactions would condition the proportion of C. albicans in the oral microbial ecosystems.     

Numerical taxonomy and laboratory identification of Actinomyces and Arachnia and some related bacteria.

A numerical taxonomic study was made on 49 facultative anaerobic Gram-positive filamentous and/or diphtheroidal organisms isolated from dental plaques, carious dentin and faeces, together with 63 reference strains belonging to the genera Actinomyces, Arachnia, Bifidobacterium, Actinobacterium, Propionibacterium, Eubacterium and Lactobacillus. They were examined for 90 unit characters covering a wide range of tests and properties. The data were subjected to computer analysis in which the simple matching coefficient (SSM) and the similarity index (SJ) were calculated, and the results of single linkage techniques and an unweighted average linkage cluster analysis technique were compared. The strains fell into six major groups (phena). The Actinomyces strains were recovered in two phena; the first contained Actinomyces israelii and the other facultative anaerobic Actinomyces, including subclusters equal to taxospecies of A. odontolyticus and A. viscosus/A. naeslundii, while the other phenon corresponded to the genera Arachnia, Actinobacterium, Bifidobacterium and Propionibacterium. The groups of Arachnia and Actinobacterium each contained one species, representing taxospecies of Arachnia propionica and Actinobacterium meyerii. Taxonomic criteria, both constant and discriminative, were selected to form a diagnostic table useful for laboratory identification of this group of organisms. Immunofluorescence supported the numerical data.     

Actinomyces denticolens Dent & Williams sp. nov: a new species from the dental plaque of cattle

D ent , V.E. & W illiams , R.A.D. 1984. Actinomyces denticolens Dent & Williams sp. nov: a new species from the dental plaque of cattle. Journal of Applied Bacteriology 56 , 183–192.
Six strains of actinomyces isolated from the dental plaque of cattle were assigned presumptively to the genus Actinomyces on the basis of Gram reaction, cellular and colony morphology and acid end-products of metabolism. This assignment was confirmed by the peptidoglycan composition which is shared with Actinomyces species from dental plaque. These cattle strains formed a homogeneous group on the basis of cell wall carbohydrate components, DNA base composition, polypep-tide molecular weight distribution and physiological reactions but could not be classified with any recognised species of Actinomyces . A new taxon Actinomyces denticolens is proposed for these strains.     

Coaggregation between Prevotella nigrescens and Prevotella intermedia with Actinomyces naeslundii strains

Abstract Using a visual coaggregation assay, 43% (6 of 14) of Prevotella nigrescens and 50% (4 of 8) of Prevotella intermedia strains coaggregated with Actinomyces naeslundii strains which represented the six Actinomyces coaggregation groups (A to F). For both species, coaggregation occurred most frequently with A. naeslundii strains from coaggregation groups C, D and E. No coaggregation was observed with Actinomyces israelii , Actinomyces odontolyticus or six oral Streptococcus species. Coaggregation was not inhibited by lactose, saliva or serum. Pretreatment of Prevotella strains with heat, SDS and proteinase K abolished coaggregation when the treated cells were added to untreated Actinomyces strains. The same pretreatment of the Actinomyces strains had no effect on their ability to coaggregate with untreated Prevotella strains. Pretreatment of all coaggregating P. nigrescens strains with trypsin abolished coaggregation, whereas the coaggregation ability of the P. intermedia and Actinomyces strains was resistant to trypsin pretreatment. Pretreatment of the strains of both Prevotella species and the Actinomyces with periodate abolished coaggregation in all cases. These results suggest that the Prevotella strains each possess a protein coaggregation adhesin, which for the P. intermedia strains is resistant to trypsin, that interacts with a non-protein receptor on the A. naeslundii strains.     

Actinomyces georgiae sp. nov., Actinomyces gerencseriae sp. nov., designation of two genospecies of Actinomyces naeslundii, and inclusion of A. naeslundii serotypes II and III and Actinomyces viscosus serotype II in A. naeslundii genospecies 2

DNAs of type strains and representative members of Actinomyces groups from the human periodontal flora and from other habitats were compared by using the S1 nuclease procedure to determine their genetic relatedness. One rather common group from the human periodontal flora, previously called "Actinomyces D08," is phenotypically distinct from, and genetically unrelated to, previously described species. We propose the name of Actinomyces georgiae for this organism; the type strain is strain ATCC 49285. Another common group from the human periodontal flora is Actinomyces israelii serotype II, which was found genetically distinct from the type strain of A. israelii (serotype I) and from other previously described species of Actinomyces. We propose the name Actinomyces gerencseriae for this organism; the type strain is strain ATCC 23860. A. naeslundii serotype I strains were distinct from the other strains studied. A separate genospecies which included strains of A. naeslundii serotypes II and III and A. viscosus serotype II was delineated. Strains of Actinomyces serotype WVA 963 constitute an additional distinct genospecies. Because there are no reliable phenotypic tests, other than serological analyses, to differentiate Actinomyces serotype WVA 963 and the two genospecies of A. naeslundii, no taxonomic changes are proposed for these three genospecies.     

Coaggregation properties of human oral Veillonella spp.: relationship to colonization site and oral ecology.

The primary habitats of oral veillonellae are the tongue, dental plaque, and the buccal mucosa. Isolates were obtained from each habitat and tested for coaggregation with a battery of other oral bacterial strains. All 59 tongue isolates tested for coaggregation were Veillonella atypica or Veillonella dispar. All but one of them coaggregated with strains of Streptococcus salivarius, a predominant inhabitant of the tongue surface but not subgingival dental plaque. These tongue isolates were unable to coaggregate with most normal members of the subgingival flora such as Actinomyces viscosus, Actinomyces naeslundii, Actinomyces israelii, and Streptococcus sanguis. In contrast, 24 of 29 Veillonella isolates, of which 20 were Veillonella parvula from subgingival dental plaque samples, coaggregated strongly with the three species of Actinomyces, S. sanguis, and other bacteria usually present in subgingival plaque, but they did not coaggregate with S. salivarius. The majority of isolates from the buccal mucosa (42 of 55) has coaggregation properties like those from the tongue. These results indicate that the three human oral Veillonella species are distributed on oral surfaces that are also occupied by their coaggregation partners and thus provide strong evidence that coaggregation plays a critical role in the bacterial ecology of the oral cavity.     

Coaggregation properties of human oral Veillonella spp.: relationship to colonization site and oral ecology

The primary habitats of oral veillonellae are the tongue, dental plaque, and the buccal mucosa. Isolates were obtained from each habitat and tested for coaggregation with a battery of other oral bacterial strains. All 59 tongue isolates tested for coaggregation were Veillonella atypica or Veillonella dispar. All but one of them coaggregated with strains of Streptococcus salivarius, a predominant inhabitant of the tongue surface but not subgingival dental plaque. These tongue isolates were unable to coaggregate with most normal members of the subgingival flora such as Actinomyces viscosus, Actinomyces naeslundii, Actinomyces israelii, and Streptococcus sanguis. In contrast, 24 of 29 Veillonella isolates, of which 20 were Veillonella parvula from subgingival dental plaque samples, coaggregated strongly with the three species of Actinomyces, S. sanguis, and other bacteria usually present in subgingival plaque, but they did not coaggregate with S. salivarius. The majority of isolates from the buccal mucosa (42 of 55) has coaggregation properties like those from the tongue. These results indicate that the three human oral Veillonella species are distributed on oral surfaces that are also occupied by their coaggregation partners and thus provide strong evidence that coaggregation plays a critical role in the bacterial ecology of the oral cavity.     

Lysogeny in heat-tolerant hydrocarbon-oxidizing actinomycetes of species Actinomyces griseomycini]

Six strains of thermophilic hydrocarbon-oxidizing Actinomyces griseomycini were tested for lysogeny. The lysogenic state was detected in the four strains and their phages were isolated. The phages isolated from the three strains were virulent and cause lysis of the host culture. All isolated phages were specific and did not cause lysis of other actinomycetes species. However, the phages had different activity towards the six studied strains of Actinomyces griseomycini. One phage induced lysis only of its indicator culture, other phages caused lysis of four strains, including those two from which no phage was isolated. All phages produced negative colonies of identical morphology. The morphology of their particles was also the same. The phages induced cross-resistance and were characterized by thermoresistance.     

高效降解生活污水中COD的根际微生物的分离筛选

采用平板划线法从人工湿地的芦苇、美人蕉的根际土壤中分离出若干细菌、真菌、放线菌菌株,在实验室条件下检测了这些菌株对灭菌生活污水和自然生活污水COD的去除效果,结果表明4株细菌、1株放线菌、1株真菌对灭菌生活污水和自然生活污水COD均具有较高的去除率。4株细菌在降解灭菌生活污水COD的去除率在48 h后依次为75.4%、78.7%、83.5%、69.8%;其在降解未灭菌生活污水COD的去除率在48 h后依次为43.4%、47.8%、50.7%、36.8%;真菌对灭菌和未灭菌生活污水COD的去除率在48 h后分别为60.2%、41.3%;放线菌对灭菌和自然生活污水COD 48 h后的去除率分别为57.8%、46.4%。这几株高效降解COD的湿地根际微生物具有潜在的应用价值。     

Coaggregation between and among human intestinal and oral bacteria

Coaggregation is believed to facilitate the integration of new bacterial species into polymicrobial communities. The aim of this study was to investigate coaggregation between and among human oral and enteric bacteria. Stationary phase cultures of 10 oral and 10 enteric species, chosen on the basis of numerical and ecological significance in their respective environments together with their ease of cultivation, were tested using a quantitative spectrophotometric coaggregation assay in all possible pairwise combinations to provide quantitative coaggregation scores. While 40% of possible partnerships coaggregated strongly for oral strains, strong interactions between oral and gut strains were considerably less common (4% incidence). Coaggregation scores were also weak between members of the intestinal microbiota (7% incidence), apart from Bacteroides fragilis with Clostridium perfringens, and Bifidobacterium adolescentis with C. perfringens. Oral and intestinal bacteria did not strongly interact, apart from B. adolescentis with Fusobacterium nucleatum, Actinomyces naeslundii with C. perfringens and F. nucleatum with Lactobacillus paracasei. Heating and sugar-addition experiments indicated that similar to oral microorganisms, interactions within intestinal bacteria and between intestinal and oral strains were mediated by lectin-carbohydrate interactions.     

The occurrence of antagonistic actinomycetes in bulgarian soils and their antibiotic properties

Of 1448 actinomycete strains isolated from different types of soils 46% exhibited an antibiotic activity. Strains exhibiting a narrow antibiotic spectrum were more usual than those exhibiting a broad spectrum. An antifungal effect was the most common property. Strains exhibiting a considerable activity against pathogenic, phytopathogenic and dermatophytic microorganisms were found among isolated cultures. Fifty-three antagonistic actinomycetes were classified in 29 species.Actinomyces candidus, Actinomyces flaveolus, Actinomyces flavoviridis andActinomyces griseovariabilis were the most common. The antibiotic spectrum of individual strains belonging to the same species was qualitatively different in most cases.     

Identification of Actinomyces israelii and Actinomyces naeslundii by Fluorescent-Antibody and Agar-Gel Diffusion Techniques

This study was an attempt to develop a fluorescent-antibody (FA) test to differentiate Actinomyces israelii and A. naeslundii as an aid in their laboratory identification. Two strains of A. israelii (X522 and A601) and two strains of A. naeslundii (X454 and X600), which had received intensive study by several investigators, were used for the immunization of rabbits. Working titers, based on tests with antigens prepared from the homologous strains and from well-established heterologous strains, were determined for each labeled antibody preparation. These conjugates and their normal serum control conjugates were used separately to stain 85 cultures of Actinomyes species and 23 strains of other species that might be confused with them. Acetone-precipitated soluble antigens from these same strains were tested with different antisera in the agar-gel diffusion test. Results showed that A. israelii (X522 and A601) and A. naeslundii (X454 and X600) labeled antiglobulins, when used at their working titers, stained most strains of their homologous species. Agar-gel diffusion results showed general agreement with those of the FA tests. The two tests appear to be equal in sensitivity, but the FA test is more specific, since several cross-reactions were noted with the agar-gel diffusion test whereas no cross-reactions were obtained with the FA reagents. Agar-gel and FA studies suggest that at least two serotypes of A. israelii may be associated with human disease. Although the majority of strains tested in this study appear to belong to a common serotype, "serotype 1," two strains of an apparent second serotype, "serotype 2," were encountered. FA staining of tissue impression smears from experimentally infected mice was successful when a counterstain, Evans Blue dye, was used.     

Purification and characterization of surface fibrils from taxonomically typical Actinomyces viscosus WVU627.

Fibrils of Actinomyces viscosus WVU627 (numerical taxonomy cluster 1) were obtained by homogenization and purified by ultrafiltration, ammonium sulfate precipitations, gel filtration, and ion-exchange chromatography. Electron microscopy and resolution of a single band by sodium dodecyl sulfate-polyacrylamide gel electrophoresis attested to the purity of the preparation. Purified fibrils were composed mainly of protein; small quantities of carbohydrate and phosphorus were detected. Immunoelectrophoresis revealed only a single precipitable antigen, which migrated slightly toward the anode, in reactions between purified fibrils and antiserum raised against either whole bacterial cells or the purified fibrils themselves. Immunoelectron microscopy with ferritin-conjugated antifibril antibody hemagglutination inhibition, and bacterial agglutination tests demonstrated that fibrils of Actinomyces viscosus cluster 1 strains shared some common antigens with clusters 2, 3, 4 and 6, but did not cross-react with typical Actinomyces naeslundii of cluster 5. Stability tests revealed that after heat or alkali treatment, the fibrils lost their antigenicity and disappeared from electron micrographs. They were affected less by sodium dodecyl sulfate, sonic, or acid treatments.     

The physicochemical and biochemical characteristics of the cell walls in M+ and M- variants of Streptococcus group A type 29

The amino acid composition of cell walls and surface proteins, isolated from virulent (M+) and avirulent (M-) streptococcal strains (group A, type 29) has been determined by the method of E. H. Beachey et al. The kinetics of the lysis and proteolysis of streptococcal cell walls with muramidase and protease obtained from Actinomyces levoris and streptolysin has been studied. The constants describing the progress rates of these processes has been determined; their values in case of both lysis and proteolysis are higher in virulent strains than in avirulent ones.     

Enzymatic/biochemical analysis of Actinomyces with commercial test kits with an emphasis on newly described species

In clinical microbiology laboratories, the identification of Actinomyces-like bacteria can be very laborious and problematic. In the present study, we focused on reactivity patterns of 4 commercial test kits, RapID ANA II, RapID 32A, RapID CB Plus, and BBL Crystal ANR ID, that could be used for rapid preliminary identification of Actinomyces isolates belonging to newly described Actinomyces and closely related species. Out of the 54 strains tested, 25 strains (46%) were correctly identified to the genus/group level by BBL Crystal ANR ID system, 16 strains (30%) by RapID 32 A, 11 strains (20%) by RapID CB Plus, and 7 strains (13%) by RapID ANA II. The main problems with these kits were due to occasional weak enzymatic and sugar fermentation reactions. In conclusion, chromogenic substrate sensitivity and specificity need to be enhanced in order to improve the reliability of the test results of these kits, and the present database updated in order to more precisely identify newly described Actinomyces and closely related species.     

Transformation of Actinomyces spp. by a gram-negative broad-host-range plasmid.

The gram-negative broad-host-range vector pJRD215 was transferred by electroporation into strains of Actinomyces viscosus or Actinomyces naeslundii at efficiencies which ranged from 10(2) to 10(7) transformants per microgram of plasmid DNA. The Actinomyces transformants expressed pJRD215-encoded resistance to kanamycin and streptomycin. Moreover, the transforming plasmid DNA had not undergone any deletions or rearrangements, nor had it integrated into the genomes of these strains.     

北部湾近海珊瑚礁区系沉积物抗菌活性放线菌类群

通过对大肠埃希菌和枯草芽胞杆菌抗菌活性初步筛选,从北部湾近海珊瑚礁区5个沉积物样品中成功分离得到51株具有不同抗菌活性的放线菌,其中9株具有较强抗菌能力。根据这9株放线菌的菌落和孢子形态,可确定它们都属于链霉菌属。 RAPD-PCR分析表明这9株放线菌为6种不同类型,16S rDNA序列和系统发生树分析表明,9株放线菌可划分到4个大的类群6种不同类型,且结果显示RAPD-PCR聚类分析与16S rDNA序列聚类分析的结果具有较大的一致性。生理生化鉴定结果表明,分离株与亲缘关系最近的放线菌模式菌株的生理生化特征均存在差异,这说明分离株为放线菌新种的可能性比较大。这6种放线菌具有较为广谱的抑菌活性,并且抑菌活性均存在一定的差异,说明其可能分泌出多种结构功能不同的活性次生代谢产物。研究结果表明,广西北部湾近海珊瑚礁区系沉积物蕴藏着丰富的可供药物开发的放线菌资源。     

猪一般型生殖道放线菌的分离鉴定与系统进化分析

2007年4月, 从患有化脓性肺炎、化脓性关节炎和心内膜炎的8周龄病死仔猪内脏器官中分离到一株细菌, 对其进行了种属关系鉴定、致病性及药物敏感性等研究。首先从表型特征和生化特性方面进行鉴定, 然后应用分子技术对其16S rDNA进行测序分析, 最后进行了动物实验和药物敏感性实验。该细菌表型特征和生化特性表明其与生殖道放线杆菌(A. hyovaginalis)非常相似; 对16S rDNA测序结果分析发现其与A. hyovaginalis III群菌株同源性高达99.2%, 系统进化分析也表明分离株与A. hyovaginalis III群菌株亲缘关系最近; 对小白鼠具有较强的致病性; 对红 霉素、庆大霉素和阿米卡星等药物高度敏感。因此, 证实分离菌株为有致病性的A. hyovaginalis III型。