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PubMedDate not supplied

Incidence of actinomycetes infection in women using intrauterine contraceptive devices.

Pancervicovaginal smears taken from 350 women using an intrauterine contraceptive device (IUD) were screened for the presence of actinomycetes organisms. Of the 12 cases in which actinomycetes-like organisms were seen in Papanicolaou-stained smears, the presence of actinomycetes organisms was confirmed by immunofluorescence in 10 cases. The prevalence of actinomycetes infection was thus 2.8% (10 of 350 cases) in the IUD users. Eight (4.3%) of 173 symptomatic subjects had actinomycetes infections. Two of the positive cases were asymptomatic. Eight of the ten patients with confirmed actinomycetes infection were using the Cu T device while two were wearing the Lippes Loop IUD. Seven of the ten patients had been using an IUD for more than two years. The time of insertion of the IUD (postpuerperal, postmenstrual or after medical termination of pregnancy) did not show any correlation with the presence of actinomycetes infection. Actinomyces israelii was responsible for the infection in eight cases while Arachnia propionica was seen in two cases. The organisms could not be grown in culture.

Actinomyces↗
PubMed1998

Taxonomy and biotransformation activities of some deep-sea actinomycetes.

Deep-sea soft sediments from trench systems and depths in the northwestern Pacific Ocean ranging from less than 300 to 10,897 m in depth have been analyzed for three target genera of actinomycetes: Micromonospora, Rhodococcus, and Streptomyces. Only culturable strains, recovered at atmospheric pressure on selective isolation media, have been examined to date. Maximum recoveries of culturable bacteria were greater that 10(7)/ml wet g sediment, but actinomycetes comprised a small proportion of this population (usually less than 1%). The target actinomycetes were isolated at all depths except from the Mariana Trench sediments. Actinomycete colonies were defined initially on the basis of colony morphologies, and preliminary identification then was made by chemotaxonomic tests. Pyrolysis mass spectrometry (PyMS) of deep-sea mycolic acid-containing actinomycetes gave excellent correspondence with numerical (phenetic) taxonomic analyses and subsequently was adopted as a rapid procedure for assessing taxonomic diversity. PyMS analysis enabled several clusters of deep-sea rhodococci to be distinguished that are quite distinct from all type strains. 16S rRNA gene sequence analysis has revealed that several of these marine rhodococci have sequences that are very similar to certain terrestrial species of Rhodococcus and to Dietzia. There is evidence for the intrusion of terrestrial runoff into these deep trench systems, and the inconsistency of the phenotypic and molecular taxonomies may reflect recent speciatiion events in actinomycetes under the high-pressure conditions of the deep sea. The results of DNA-DNA pairing experiments point to the novelty of Rhodococcus strains recovered from hadal depths in the Izu Bonin Trench. Biotransformation studies of deep-sea bacteria have focused on nitrile compounds. Nitrile-metabolizing bacteria, closely related to rhodococci, have been isolated that grow well at low temperature, high salt concentrations, and high pressures, suggesting that they are of marine origin or have adapted to the deep-sea environment.

Actinomycetales↗
PubMed1992

Pyrolysis mass spectrometry as a method for the classification, identification and selection of actinomycetes.

Pilot experiments were designed to determine the potential of Curie-point pyrolysis mass spectrometry (PyMS) in the classification, identification and typing of industrially significant actinomycetes, and for the detection of target and novel actinomycetes needed for pharmacological screening programmes. The results indicate that the method is of value for the separation of actinomycetes at and below the species level, in the detection and circumscription of novel actinomycetes, and for the detection of identical and duplicated strains. There is also evidence that the pyrolysis system will permit the identification of target actinomycetes directly from selective isolation plates. PyMS is one of the methods that should be used to generate polyphasic taxonomies of actinomycete genera.

Actinomycetales↗
PubMed1983

Exposure of water consumers to mesophilic actinomycetes.

In autumn 1978 an epidemic of respiratory disease resembling allergic alveolitis occurred in a small Finnish community. The disease was caused by repeated exposures to tap water aerosol. The raw water of the community and the sand filters of the purification system were heavily contaminated with mesophilic actinomycetes. Fourteen different strains of actinomycetes were isolated. Exposed persons with and without symptoms as well as unexposed control persons were tested for antibodies against five of these actinomycetes and against Enterobacter agglomerans. Both the exposed and the control persons had antibodies to actinomycetes but the exposed persons had antibodies against more actinomycete strains than the control persons. Precipitating antibodies against E. agglomerans were also found in control persons as well as in patients. There was a significant difference between the patients and the exposed healthy persons in bacterial agglutination tests with flagellar antigen of one E. agglomerans strain. However, the role of mesophilic actinomycetes and E. agglomerans in the aetiology of the disease could not be firmly established.

Aerosols↗
PubMed2003

Patterns of antimicrobial activities from soil actinomycetes isolated under different conditions of pH and salinity.

AIMS: To evaluate the patterns of the production of antimicrobial compounds by diverse collection of actinomycetes isolated from different geographies under alternative conditions of pH and salinity in the media. METHODS AND RESULTS: Actinomycetes were grouped based on their method of isolation and their phenotype diversity was determined by total fatty acid analysis. A total of 335 representative isolates, including 235 Streptomyces species and 100 actinomycetes from other taxa, were screened for the production of antimicrobial activities against a panel of bacteria, filamentous fungi and yeasts, including some of clinical relevance. Production of antimicrobial activities was detected in 230 strains. In the case of the genus Streptomyces, 181 antimicrobial activities (77% of the tested isolates) were recorded. The activities observed among the other actinomycetes taxa were lower (49% of the tested isolates). CONCLUSIONS: The results of this study support the idea that species of actinomycetes isolated in alternative selective conditions of pH and salinity present a significant capacity to produce compounds with antibacterial or antifungal activity. The best group of isolates in terms of production of active secondary metabolites was the one isolated in saline conditions. SIGNIFICANCE AND IMPACT OF THE STUDY: The results demonstrate that these actinomycetes strains isolated in alternative selective conditions of pH and salinity and collected from diverse geographical locations present a significant capacity to produce compounds with antibacterial or antifungal activity.

Actinobacteria↗
PubMed2004

[Antimicrobial activity of actinomycetes isolated from aquatic environments in southern Chile].

BACKGROUND: The easy access and inappropriate use of antimicrobials led to selection and spread of resistant microorganisms strains. It is imperative to search for new and more effective antimicrobials. One strategy is the screening of metabolites produced by microorganisms found in the environment. Actinomycetes are a potential source of new drugs. AIM: To isolate actinomycetes from sediments of Chilean rivers and lakes and to screen them for antimicrobial activity against reference bacterial strains and pathogenic fungi. MATERIAL AND METHODS: Actinomycetes were isolated from sediment samples, using casein-starch agar. The antimicrobial activity against 3 bacterial species and 7 fungal species was tested using the disc diffusion method. For the extraction of active metabolites, culture broths of antagonistic actinomycetes were extracted with organic solvents followed by testing the antibiotic activity. RESULTS: A total of 62 strains of actinomycetes were isolated, mainly Streptomyces sp (83.9%). Thirty six strains (58.1%) showed antimicrobial activity, mainly against Bacillus subtilis and Candida albicans. Some isolates inhibited a wide spectrum of indicator strains, like LRI 4A strain (Streptomyces sp) that inhibited Bacillus subtilis, Candida albicans and 4 filamentous fungi. CONCLUSIONS: Lakes and rivers of Southern Chile are an important reservoir of antagonistic actinomycetes, a potential source of new drugs.

Actinobacteria↗
PubMed1986

[Actinomycetes--the test-organisms of genetic engineering].

The paper contains a short review of the data on using the methods of genetic engineering in studies of genetics and molecular biology in Streptomyces. The techniques of DNA introduction into actinomycetes and wide-spread vectors are briefly described. The origin of the actinomycete plasmids as chromosomal segments capable of autonomous replication is discussed. In this view, it is suggested that genetic instability in actinomycetes is connected with excision of specific DNA sequences from the chromosome at frequencies characteristic of recombination events. Also, amplification of short DNA segments within the chromosome resulting in tandem repeats is a consequence of unequal crossing over between direct repeats flanking the amplifying DNA and, possibly, of induction of replication of this DNA. The data on molecular cloning of actinomycete genes for primary metabolism and those for resistance to and biosynthesis of antibiotics, on using actinomycetes as the hosts for foreign genes to be expressed, as well as on analysis of nucleotide sequences of actinomycete DNA, are presented.

Actinomycetaceae↗
PubMed2003

Detection of eubacterial 3-hydroxy-3-methylglutaryl coenzyme a reductases from natural populations of actinomycetes.

Three natural populations of actinomycetes were investigated by PCR for the presence of type I 3-hydroxy-3-methylglutaryl coenzyme A reductase (HMG CoA), a gene associated with isoprenoid biosynthesis. The populations were obtained from an agricultural site (69 isolates), a coastal salt marsh (220 isolates), and a desert soil (96 isolates). A set (34) of standard actinomycete reference strains were also investigated. The target gene was only detected in 5 of the 419 actinomycetes screened, which represented 4 from the coastal salt marsh and one reference strain. The isolates that contained the gene were taxonomically diverse (4 Streptomyces spp. and 1 Nocardia sp.). These results suggest that type I HMG CoA containing pathways are rare in actinomycetes and their distribution within actinomycetes populations is not random.

Actinobacteria↗
PubMed2005

Antifungal activities of actinomycete strains associated with high-altitude sagebrush rhizosphere.

The antifungal-producing potential of actinomycete populations from the rhizosphere of low-altitude sagebrush, Artemisia tridentata, has been examined. In a continued investigation of new sources of antifungal-producing microorganisms, this study examined the antifungal-producing potential of actinomycetes from the rhizosphere of high-altitude A. tridentata. With high-altitude sagebrush, rhizosphere soil actinomycete numbers were one to four orders of magnitude higher than those found in nonrhizosphere bulk soils and different from those found with the low-altitude plants. A total of 122 actinomycete isolates was screened against nine fungal species and six bacterial species for the production of antimicrobial compounds. Four rhizosphere isolates, Streptomyces amakusaensis, S. coeruleorubidus, S. hawaiiensis and S. scabies, showed broad-spectrum antifungal activity against three or more fungal species in plate assays. In liquid antagonism assays, mycelium production by Aspergillus niger was reduced by up to 50% by two of the actinomycete isolates. These results demonstrate the potential of rhizosphere microbiology in the search for new antimicrobials.

Actinobacteria↗
PubMed2006

Novel family of cholesterol esterases produced by actinomycetes bacteria.

Although cholesterol esterase (CHE; EC 3.1.1.13) is widespread in nature, CHEs from Streptomyces lavendulae and Streptomyces sp. X9 are the only known CHEs produced by actinomycetes. We purified CHEs from S. avermitilis JCM5070, and S. griseus IFO13350 and identified four new CHEs from actinomycetes. The enzymic properties of the CHEs from Streptomyces sp. X9, S. avermitilis, and S. griseus including substrate specificity, sensitivity to inhibitors and optimal conditions for catalysis were similar. We identified genes for the CHEs from Streptomyces sp. X9 and S. avermitilis and the encoded predicted sequences comprised 217 and 214 amino acid residues, respectively, with 64% similarity. The CHEs from Streptomyces sp. X9 and S. avermitilis were also 54 and 57% similar, respectively, to S. lavendulae CHE, indicating that these CHEs are orthologs. Phylogenetic analysis showed that they are distantly related to the conventional lipase/esterase type CHEs from mammals, yeasts and other bacteria. The actinomycetes CHEs did not have the Gly-Xaa-Ser-Xaa-Gly sequence that is conserved in the lipase/esterase family. A database search showed that orthologs of this type of CHE were restricted to actinomycetes. These findings imply that the actinomycetes CHEs constitute a novel family of cholesterol esterases.

Amino Acid Sequence↗
PubMed2006

Fungi and actinomycetes associated with Meloidogyne spp. eggs and females in China and their biocontrol potential.

A survey was conducted to determine the microflora on eggs and females of Meloidogyne spp. collected from plant roots and infested soil in China. A total of 455 fungal isolates belonging to 24 genera and 52 isolates of actinomycetes were obtained from 28 samples from greenhouses and fields in Hainan, Yunnan, Fujian, Hebei, Shandong, and Beijing. The predominant fungal species were Paecilomyces lilacinus (49.3% of the isolates), Fusarium spp. (7.9%), Pochonia chlamydosporia (6.9%), Penicillium spp. (5.7%), Aspergillus spp. (3.2%), and Acremonium spp. (2.8%). Actinomycetes were frequently encountered (10.3%) as well. A total of 350 isolates of nematophagous fungi and actinomycetes were evaluated for their parasitism of eggs and effects on egg hatch and juvenile mortality in vitro. Pathogenicity varied among isolates, and 29.1% of isolates parasitized over 90% eggs 4 days after inoculation. Results also show that seven isolates of fungi and actinomycetes reduced egg hatch rates to less than 10% contrasted to the control of 65.8%, and three isolates killed all hatched juveniles after 7 days. Seventeen fungal isolates and four actinomycete isolates with high pathogenicity in vitro were selected to test biocontrol efficacy in the greenhouse. They reduced tomato root gall index by 13.4-58.9% compared to the no treatment control.

Actinobacteria↗
PubMed2006

Discovery of novel metabolites from marine actinomycetes.

Recent findings from culture-dependent and culture-independent methods have demonstrated that indigenous marine actinomycetes exist in the oceans and are widely distributed in different marine ecosystems. There is tremendous diversity and novelty among the marine actinomycetes present in marine environments. Progress has been made to isolate novel actinomycetes from samples collected at different marine environments and habitats. These marine actinomycetes produce different types of new secondary metabolites. Many of these metabolites possess biological activities and have the potential to be developed as therapeutic agents. Marine actinomycetes are a prolific but underexploited source for the discovery of novel secondary metabolites.

Actinobacteria↗
PubMed2002

The detection of diverse aminoglycoside phosphotransferases within natural populations of actinomycetes.

The conserved nature of the genes that code for actinomycete secondary metabolite biosynthetic pathways suggests a common evolutionary ancestor and incidences of lateral gene transfer. Resistance genes associated with these biosynthetic pathways also display a high degree of similarity. Actinomycete aminoglycoside phosphotransferase antibiotic resistance enzymes (APH) are coded for by such genes and are therefore good targets for evaluating the bioactive potential of actinomycetes. A set of universal PCR primers for APH encoding genes was used to probe genomic DNA from three collections of actinomycetes to determine the utility of molecular screening. An additional monitoring of populations for the predominance of specific classes of enzymes to predict the potential of environmental sites for providing isolates with interesting metabolic profiles. Approximately one-fifth of all isolates screened gave a positive result by PCR. The PCR products obtained were sequenced and compared to existing APH family members. Sequence analysis resolved the family into nine groups of which six had recognizable phenotypes: 6'-phosphotransferase (APH(6)), 3'-phosphotransferase (APH(3)), hydroxyurea phosphotransferase (HUR), peptide phosphotransferase, hygromycin B phosphotransferase (APH(7")) and oxidoreductase. The actinomycetes screened fell into seven groups, including three novel groups with unknown phenotypes. The strains clustered according to the environmental site from where they were obtained, providing evidence for the movement of these genes within populations. The value of this as a method for obtaining novel compounds and the significance to the ecology of antibiotic biosynthesis are discussed.

Actinobacteria↗
PubMed2005

Bacterial, azotobacter, actinomycetes, and fungal population in soil after diazinon, imidacloprid, and lindane treatments in groundnut (Arachis hypogaea L.) fields.

Bacterial, azotobacter, actinomycetes, and fungal populations were determined in groundnut (Arachis hypogaea L.) fields between July and November for three consecutive years (1997-1999) after insecticide treatments. Diazinon was applied for both seed and soil treatments. However, imidacloprid and lindane were used for seed treatments. An average half-life (t1/2) of diazinon in seed- and soil-treated fields was found to be 29.32 and 34.87 days, respectively. Its residues were found for 60 days in both cases. In diazinon seed treatment, an increase in azotobacter, fungi, and actinomycetes populations was observed in samples from the 15th and 30th days, and this trend continued until crop harvest. However, the bacterial population had not been affected by this treatment. The diazinon soil treatment had indicated some significant adverse effects on fungi and actinomycetes population, which recovered after 30 days. The population of bacteria and azotobacter increased significantly in this treatment. The residues of imidacloprid and lindane were found for 90 and 120 days with an average half-life of 40.9 and 53.3 days, respectively. Imidacloprid had no significant effect on fungi and actinomycetes populations up to 15 days, and between 15 to 60 days some adverse effects were indicated. However, some significant increases in bacterial and azotobacter population were observed. Lindane had no effect on bacterial and fungal population. However, its adverse effects were observed in actinomycetes and azotobacter populations between 30 to 60 days.

Actinobacteria↗
PubMed2001

Actinopolymorpha singaporensis gen. nov., sp. nov., a novel actinomycete from the tropical rainforest of Singapore.

A novel actinomycete was isolated from soil in the tropical rainforest of Singapore. The cells of this actinomycete are highly pleomorphic. In the early stages of growth, most cells are of irregular squarish shape and varied sizes. Cells remain attached after cell division, often forming chains or aggregates of a few cells. Cells at the end of a chain tend to elongate. With prolonged cultivation, cells show different degrees of elongation and enlargement, producing branched hyphae of uneven thickness. At the periphery of the colony, long hyphae form, which are divided into alternating segments of elongated cells and chains of squarish cells. This actinomycete is considerably salt-tolerant, able to grow in the presence of 15% NaCl. Chemotaxonomically, it contains LL-diaminopimelic acid (DAP) in the cell wall, type PI phospholipids and MK-9(H6) as the predominant menaquinone. 16S rDNA sequence analysis assigned this actinomycete to the family Nocardioidaceae, but its 16S rDNA shared no more than 91.2% sequence similarity with other members of the family. Based on phenotypic, chemotaxonomic and phylogenetic evidence, it is proposed that this actinomycete be classified as a new species in a new genus, Actinopolymorpha singaporensis gen. nov., sp. nov.

Actinomycetales↗
PubMed2003

Rapid identification of filamentous actinomycetes to the genus level using genus-specific 16S rRNA gene restriction fragment patterns.

A rapid method for identifying filamentous actinomycete genera was developed based on 16S rRNA gene restriction fragment patterns. The patterns were generated by using specific restriction endonucleases to perform in silico digestions on the 16S rRNA gene sequences of all validly published filamentous actinomycete species. The method was applied to identifying actinomycete isolates from soil. Amplified 16S rDNA of soil actinomycetes was restricted with selected endonucleases and electrophoresed on agarose gels. The restriction fragment patterns of the unknown isolates were easily compared to the established patterns. Significantly, the genus Streptomyces could be differentiated from all other actinomycete genera by using only four restriction endonucleases, Sau3AI, AsnI, KpnI and SphI. This could be achieved in a time period of as little as a week, following PCR-template DNA isolation by a simple method. The identification method allowed unknown, non-Streptomyces soil isolates to be identified to a genus or small subgroup of genera. The genera in these subgroups could, in some cases, be distinguished by virtue of colony-morphology differences.

Actinobacteria↗
PubMed2000

Detection of antitumor and antimicrobial activities in marine organism associated actinomycetes isolated from the Taiwan Strait, China.

The purpose of this work was to screen the actinomycetes having antitumor or antimicrobial activity, which were isolated from the surface, epidermis and intestines of sea plants and animals collected from the Taiwan Strait, China. Antitumor activity was studied by the MTT assay and DNA target activity was studied by the biochemical induction assay while antimicrobial activity was determined by observing bacterial and fungal growth inhibition. 20. 6% of marine actinomycete cultures displayed cytotoxic activity on P388 cells at dilutions at and below 1:320 and 18.6% on KB cells. 2. 96% of marine actinomycete cultures displayed inducing activity. Among all marine actinomycetes isolated, the genus Micromonospora has the highest positive rate of inducing activity. However, most antimicrobial activity was found in the genus Streptomyces. These results indicate that marine organism associated actinomycetes could be a promising source for antitumor and antimicrobial bioactive agents.

Actinomycetales↗
PubMed2001

Use of direct-infusion electrospray mass spectrometry to guide empirical development of improved conditions for expression of secondary metabolites from actinomycetes.

A major barrier in the discovery of new secondary metabolites from microorganisms is the difficulty of distinguishing the minor fraction of productive cultures from the majority of unproductive cultures and growth conditions. In this study, a rapid, direct-infusion electrospray mass spectrometry (ES-MS) technique was used to identify chemical differences that occurred in the expression of secondary metabolites by 44 actinomycetes cultivated under six different fermentation conditions. Samples from actinomycete fermentations were prepared by solid-phase extraction, analyzed by ES-MS, and ranked according to a chemical productivity index based on the total number and relative intensity of ions present in each sample. The actinomycete cultures were tested for chemical productivity following treatments that included nutritional manipulations, autoregulator additions, and different agitation speeds and incubation temperatures. Evaluation of the ES-MS data from submerged and solid-state fermentations by paired t test analyses showed that solid-state growth significantly altered the chemical profiles of extracts from 75% of the actinomycetes evaluated. Parallel analysis of the same extracts by high-performance liquid chromatography-ES-MS-evaporative light scattering showed that the chemical differences detected by the ES-MS method were associated with growth condition-dependent changes in the yield of secondary metabolites. Our results indicate that the high-throughput ES-MS method is useful for identification of fermentation conditions that enhance expression of secondary metabolites from actinomycetes.

Actinomycetales↗