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PubMed1988

A simple screening method for insecticidal substances from actinomycetes.

A simple and selective assay system was developed in the search for new insecticidal substances from Actinomycetales strains propagated on solid culture media. The strains were first tested for their ability to produce antimicrobial compounds. Only strains displaying weak or no activity were retained and screened in the insecticidal bioassay. Microbial solid cultures were given as food to larvae and to adults of Musca domestica to detect insecticide producers. A second phase, after extraction of the active compounds, consisted of an evaluation of the insecticidal potency and a primarily biological identification of the products synthesized by the selected strain. Of 6,280 actinomycete strains which were screened, 47 were active but only 30 of these were finally chosen in the second phase of screening. All these strains, except one, produced known metabolites such as piericidins, avermectins or valinomycin. The one strain, CL307-24, and its insecticide products appeared novel and will be the topic of further study.

Actinomycetales↗

PubMed1972

Immunological determination of Mycobacterium leprae by means of cytoplasmic antigens.

Mycobacterium leprae was isolated and purified from lepromas, the spleen, and the liver of leprosy patients. An immunodiffusion analysis of the cytoplasms obtained from four lots of M. leprae and M. lepraemurium, 295 strains of different actinomycetales, and 12 other bacteria was performed with the use of the cytoplasm antisera. Immunological relationships were revealed between the cytoplasms of M. leprae, M. lepraemurium, M. avium, M. gallinarum, M. tuberculosis, M. simiae, M. kansasii, M. chitae, M. capsulatum, Actinomyces israelii, A. naeslundii, and some strains of saprophytic mycobacteria. These studies led to the proposed concept of the immunological evolution of M. leprae and M. lepraemurium and an Actinomyces-like progenitor through M. avium-M. gallinarum and to a proposal for the polyvalent vaccine currently being developed by this research group.

Actinomycetales↗

PubMed1995

[Bioactive compounds from marine actinomycetes].

Studies of the origin of bioactive metabolites of marine actinomycetes are reviewed. Structures and properties of new metabolites from indigenous marine bacteria from Actinomycetales order, such as a benzanthraquinone antibiotic from a strain of the Chainia purpurogena, istamycins, aplasmomycins, altemicidin, new phenazine esters. C13-butanolide, marinone and debromomarinone, palmyromycin, urauchimicins and some others compounds are presented. Prospects of marine biotechnology and microbiology (with considerable emphasis on the development of the basis biology of marine microorganisms in cultures collection) are discussed.

Actinomycetales↗

PubMed1977

Morphology of colony variants of the rough form of Dermatophilus spp.

A technique is described for the preparation of intact colonies of Dermatophilus and their study under the scanning electron microscope. Using this technique with 38 strains of the organism it is possible to describe for the first time the patterns of colony morphology and to study the relationship of hyphae, cocci and zoospores in situ. Colonies were found to possess both vegetative and aerial hyphae. The various patterns of mycelial activity and structure that were seen raised serious doubts about the previous concepts of the mode of propagation and thus the classification of Dermatophilus within the Actinomycetales.

Actinomycetales↗

PubMed2003

High diversity among feather-degrading bacteria from a dry meadow soil.

The aim of this study was to determine the diversity of cultivable bacteria able to degrade feathers and present in soil under temperate climate. We obtained 33 isolates from soil samples, which clustered in 13 ARDRA groups. These isolates were able to grow on solid medium with pigeon feathers as sole carbon and nitrogen source. One representative isolate of each ARDRA group was selected for identification and feather degradation tests. The phylogenetic analysis of 16S rDNA gene fragments revealed that only 4 isolates were gram positives. Two other isolates belonged to the Cytophaga-Flavobacterium group, and the remaining to Proteobacteria. High keratinolysis activity was found for strains related to Bacillus, Cytophagales, Actinomycetales, and Proteobacteria. The 13 selected strains showed variable efficiency in degrading whole feathers and 5 strains were able to degrade maximum 40% to 98% of the whole feathers. After 4 weeks incubation, five strains grown on milled feathers produced more than 0.5 U keratinase per mL. Keratinase activities across the 13 strains were positively correlated with the percentage of feather fragmentation and protein concentration.

Animals↗

PubMed2005

Isolation and identification of bacteria from spent nuclear fuel pools.

The aim of the present research was to isolate and identify bacteria from spent nuclear fuel pools of a Spanish nuclear power plant. Water samples were collected and inoculated onto different culture media to isolate the highest number of species. 16S rDNA fragments from colonies growing on solid media were amplified and analysed by denaturing gradient gel electrophoresis. Sequencing revealed the presence of 21 different bacteria belonging to several phylogenetic groups (alpha, beta, and gamma-Proteobacteria, Actinomycetales, Flavobacterium, and the Bacillus/Staphylococcus group). The isolation of these microorganisms in this particular environment (oligotrophic and radioactive) is highly interesting because of the possibility of their being used for the bioremediation of radionuclide-contaminated waters.

Bacteria↗

PubMed2006

Conformational analyses of mycothiol, a critical intracellular glycothiol in Mycobacteria.

Intracellular thiols are essential biomolecules, which play several critical roles in living organisms including controlling intracellular redox potential and acting as cofactors for several vital detoxification enzymes including S-transferases and formaldehyde dehydrogenases. The tripeptide gamma-L-glutamyl-L-cysteinylglycine, more commonly known as glutathione, is well known as the major intracellular thiol in eukaryotes and in some bacteria. However, glutathione is absent in the Actinomycetales bacteria such as Mycobacteria and Streptomyces and is believed to be replaced by 1-D-myo-inosityl-2-(N-acetyl-L-cysteinyl)amido-2-deoxy-alpha-D-glucopyranoside, mycothiol, in these organisms. Although much is known about the chemistry and biochemistry of glutathione, currently much less is known concerning mycothiol and its properties. The structure of mycothiol is composed of a glycoside linkage between myo-inositol and D-glucosamine with an N-acetyl-L-cysteine linked to the 2'-amino group of the d-glucosamine moiety. Mycothiol is currently of intense interest due to its essential role in the cellular physiology of Mycobacteria, such as Mycobacterium tuberculosis, and its possible role in antimycobacterial drug resistance. A detailed investigation of its chemistry is therefore essential in ameliorating our knowledge of this key glycothiol, and in shedding additional light on its biochemical role in these pathogenic organisms. This report presents a detailed conformational analysis of mycothiol utilizing a variety of force fields and stochastic search protocols. Cluster analyses of energetically low lying conformations have indicated the presence of several key conformations that are populated in the gas phase and with implicit water solvation. These conformations are compared to recent NMR studies on a derivative of mycothiol. This information should be an important contribution to our basic understanding of the chemistry of this glycothiol and critical in the design of novel inhibitors of pathogen enzymes that require it.

Carbohydrate Conformation↗

PubMed2005

Diversity of biphenyl degraders in a chlorobenzene polluted aquifer.

Biphenyl degrading bacteria (40 strains) have been isolated along a gradient of chlorobenzene pollution from an aquifer which did not contain any PCB to answer the question of how metabolic/catabolic abilities exist in ecosystems that have not been stressed with the relevant substrates is important for intrinsic bioremediations. Only few of the isolates were characterized by 16S rRNA gene sequence analyses as Pseudomonas species while the majority were Gram-positive, belonging to the order Actinomycetales and representing the genera Rhodococcus and Arthrobacter. The strains could grow on a variety of chlorobenzoates but no pattern of substrate usage and phylogeny or pollution gradient could be found. Strains which were able to grow on 2,5-dichlorobenzoate were often also able to use 3,4- and 3,5-dichloro- and 2,3,5-trichlorobenzoate or those using 2-chlorobenzoate could usually use 2,6-dichlorobenzoate as well. From that results, it is concluded that a highly diverse, basic metabolic activity for PCB degradation existed at this site despite the absence of PCB.

Biodegradation, Environmental↗

PubMed2004

Is cancer just an incurable infectious disease?

The word 'cancer' is of Latin derivation and means crab. By the turn of the 20th Century organized medicine had come to the conclusion that it was not a matter of whether infectious disease caused cancer, but which one. For over two hundred years a cancer germ had been discovered and rediscovered, named and renamed, each scientist adding to the knowledge, but to no avail. Then, in 1910, certain American medical powers did a 180-degree rotation, deciding that cancer was not caused by a microbe, and that anyone who thought otherwise was a heretic, a charlatan or a quack. But Dr. Virginia Livingston and her network were none of the above, their meticulous peer-reviewed research and publications, done at the height of US post World War II technology. And Dean Burk, Head of Cell Chemistry at the NCI went so far as to say that Livingston's cancer germ was as real and certain as anything known about cancer. Researcher, MD Alan Cantwell Jr. grew up thinking that all germs responsible for the important diseases were supposed to have already been discovered. But much to his dismay, he found one that was left out: the cancer germ. Cantwell already knew that for finding this, Livingston had already been branded by traditional medicine, leaving what he thought to be perhaps the major discovery of the 20th century largely discredited. The striking analogy between cancer and tuberculosis was noticed long before the tubercle bacillus was discovered. In 1877, Sir John Simon clearly pointed out the similarity and in fact argued very strongly in favor of a microbial origin for cancer. But Simon's vindication would have to wait for Livingston's germ, which although tuberculosis-like, was not tuberculosis but an atypical form of this mycobacterium, melded from the mycobacterium and other related Actinomycetales. Had medical science and the powers that be spent as much time in investigating and destroying Livingston's germ as they did in attacking her and those around her, cancer might be curable today.

Animals↗

PubMed1997

The use of a 16s rDNA directed PCR for the detection of endodontopathogenic bacteria.

The study evaluates a 16S rDNA directed polymerase chain reaction (PCR) to detect and differentiate bacteria in necrotic root canal samples. The examination focused on species that are fastidious concerning culture or are difficult to differentiate after culturing by biochemical methods. In the described PCR assay, a universal 16S rDNA directed forward primer in combination with a highly specific reversed one was used to amplify taxon specific gene fragments of 230 to 950 bp length. A similar PCR reaction using a universal 16S rDNA reversed primer was also established to demonstrate bacteria in root canal specimens in general. A first application of this method revealed the presence of Actinomycetales-species, Fusobacterium nucleatum, "Streptococcus milleri," and, presumably for the first time described in infected root canals, Bacteroides forsythus. The identity of amplificons was confirmed by generating sequence information and comparison to gene databanks.

Adult↗

PubMed1975

Further analysis of acyl-CoA-ACP-transacylases of mycobacterium smegmatis. Identification of a long chain alkyl malonyl-CoA-ACP-transacylase.

Homogenates were prepared from three sources, Mycobacterium smegmatis Saccharomyces cerevisiae and Escherichia coli and tested for docosyl malonyl-CoA-ACP transacylase activity, using ACP purified from E. coli strain B and [2R, 2S, 1, 3-14C2] docosyl malonyl-CoA synthesized chemically, as substrates. Only homogenates of M. semegmatis showed positive transacylase activity. Successive chromatographies on Sephadex G-150 and then on DEAE-Sephadex A-50 prove that neither the palmityl-CoA-ACP-transacylase nor the malonyl-CoA-ACP-transacylase of M. smegmatis are responsible for this activity. The question concerning the identity of the enzyme with one of the two entities exhibiting acetyl-CoA-ACP-transacylase activity, previously identified in homogenates of this microorganism (1973 this journal, 55, 1381-1394), remains open for further experimentation. The physiological significance of the presence of a long chain alkyl malonyl-CoA-ACP-transacylase in homogenates of M. smegmatis, a representative of the Actinomycetales, is discussed in relation to the mechanism of the biosynthesis of mycolic acids. Chromatography on Sephadex G-100 showed that the substrate of the enzyme, docosyl malonyl-CoA, exists, in 50 mu molar aqueous solution, mostly in an aggregated state. A factor has been identified in the homogenates, which in the presence of radioactive docosyl malonyl-CoA, leads to the formation of a radioactive material showing an apparent molecular weight less than 10000. The nature of this material is discussed.

Acetyl Coenzyme A↗

PubMed2003

The genome stability in Corynebacterium species due to lack of the recombinational repair system.

Corynebacterium species are members of gram-positive bacteria closely related to Mycobacterium species, both of which are classified into the same taxonomic order Actinomycetales. Recently, three corynebacteria, Corynebacterium efficiens, Corynebacterium glutamicum, and Corynebacterium diphtheriae have been sequenced independently. We found that the order of orthologous genes in these species has been highly conserved though it has been disrupted in Mycobacterium species. This synteny suggests that corynebacteria have rarely undergone extensive genome rearrangements and have maintained ancestral genome structures even after the divergence of corynebacteria and mycobacteria. This is the first report that the genome structures have been conserved in free-living bacteria such as C. efficiens and C. glutamicum, although it has been reported that obligate parasites such as Mycoplasma and Chlamydia have the stable genomes. The comparison of recombinational repair systems among the three corynebacteria and Mycobacterium tuberculosis suggested that the absence of recBCD genes in corynebacteria be responsible for the suppression of genome shuffling in the species. The genome stability in Corynebacterium species will give us hints of the speciation mechanism with the non-shuffled genome, particularly the importance of horizontal gene transfer and nucleotide substitution in the genome.

Corynebacterium↗

PubMed1996

Actinomycosis, nocardiosis, and actinomycetoma.

Cases of actinomycosis, nocardiosis, and actinomycetoma are seen infrequently but consistently in the United States. When they are found, diagnosis can be difficult because of their resemblance to other bacterial, mycobacterial, and fungal infections. This article reviews the clinical presentation, therapy, and laboratory diagnosis of these actinomycetales.

Actinomyces↗

PubMed2000

Ionophore use and toxicosis in cattle.

Ionophores comprise a rapidly expanding class of antibiotics produced by filamentous branching bacteria of the order Actinomycetales. The use of ionophores as coccidiostats and growth promotants has resulted in the occurrence of toxicoses in target and nontarget species. Clinical and pathologic effects of ionophore poisoning are caused by bioactivity and damage to excitable tissues such as cardiac muscle, skeletal muscle, smooth muscle, and the nervous system. Ionophore toxicoses are often related to errors in feed mixing, so the practitioner should give primary importance to the removal of suspect feeds and testing to confirm excessive exposure.

Animals↗

PubMed2005

Biological chemistry of naturally occurring thiols of microbial and marine origin.

The presence of thiols in living systems is critical for the maintenance of cellular redox potentials and protein thiol-disulfide ratios, as well as for the protection of cells from reactive oxygen species. In addition to the well-studied tripeptide glutathione (gamma-Glu-Cys-Gly), a number of compounds have been identified that contribute to these essential cellular roles. This review provides a survey of the chemistry and biochemistry of several critically important and naturally occurring intracellular thiols such as coenzyme M, trypanothione, mycothiol, ergothioneine, and the ovothiols. Coenzyme M is a key thiol required for methane production in methogenic bacteria. Trypanothione and mycothiol are very important to the biochemistry of a number of human pathogens, and the enzymes utilizing these thiols have been recognized as important novel drug targets. Ergothioneine, although synthesized by fungi and the Actinomycetales bacteria, is present at significant physiological levels in humans and may contribute to single electron redox reactions in cells. The ovothiols appear to function as important modulators of reactive oxygen toxicity and appear to serve as small molecule mimics of glutathione peroxidase, a key enzyme in the detoxification of reactive oxygen species.

Drug Design↗

PubMed1997

Biosynthesis of mycothiol: elucidation of the sequence of steps in Mycobacterium smegmatis.

Several members of the Actinomycetales, including the medically important mycobacteria, produce 1-D-myo-inosityl-2-(N-acetyl-L-cysteinyl)amino-2-deoxy-alpha-D- glucop yranoside (trivial name mycothiol) as their principal low-molecular-mass thiol. The pseudo-disaccharide component of mycothiol, 1-D-myo-inosityl-2-amino-2-deoxy-alpha-D-glucopyranoside (alpha-D-GI), was synthesized by ligation of 1-D,L-2,3,4,5, 6-penta-O-acetyl-myo-inositol to 3,4,6-tri-O-acetyl-2-deoxy- 2-(2,4-dinitrophenylamino)-alpha-D-glu- copyranosyl bromide to give, in the first instance, an isomeric mixture of alpha- and beta-linked pseudo-disaccharides. The alpha-coupled D,D and D,L isomers, alpha-D-GI and alpha-L-GI respectively, were purified from the mixture by TLC, followed by removal of the protecting groups. A cell-free extract of Mycobacterium smegmatis catalysed the ligation of cysteine, acetate and alpha-D-GI in the presence of ATP and Mg2+ to form mycothiol, as judged by HPLC. When no acetate was added to the incubation mixture, an additional thiol accumulated. In the presence of [14C]acetate no radiolabel was recovered in this species, but only in mycothiol. The additional thiol was isolated as the bimane derivative, and 1H and 1H-1H COSY NMR spectra confirmed its identity as desacetylmycothiol. A more complete conversion of desacetylmycothiol into mycothiol was achieved in the presence of acetyl-S-CoA. These results indicate that the biosynthesis of mycothiol proceeds by the sequential addition of cysteine and acetate to alpha-D-GI. The inositol moiety appears to be an important determinant of specificity, since alpha-L-GI was poorly utilized.

Acetates↗

PubMed2002

Aerobic and facultatively anaerobic cellulolytic bacteria from the gut of the termite Zootermopsis angusticollis.

AIMS: To demonstrate the occurrence of cellulolytic bacteria in the termite Zootermopsis angusticollis. METHODS AND RESULTS: Applying aerobic cultivation conditions we isolated 119 cellulolytic strains from the gut of Z. angusticollis, which were assigned to 23 groups of aerobic, facultatively anaerobic or microaerophilic cellulolytic bacteria. 16S rDNA restriction fragment pattern and partial 16S rDNA sequence analysis, as well as numerical taxonomy, were used for the assignment of the isolates. The Gram-positive bacteria of the actinomycetes branch could be assigned to the order Actinomycetales including the genera Cellulomonas/Oerskovia, Microbacterium and Kocuria. The Gram-positive bacteria from the order Bacillales belonged to the genera Bacillus, Brevibacillus and Paenibacillus. Isolates related to the genera Afipia, Agrobacterium/Rhizobium, Brucella/Ochrobactrum, Pseudomonas and Sphingomonas/Zymomonas from the alpha-proteobacteria and Spirosoma-like from the "Flexibacteriaceae" represented the Gram-negative bacteria. CONCLUSIONS: A cell titre of up to 10(7) cellulolytic bacteria per ml, determined for some isolates, indicated that they may play a role in cellulose digestion in the termite gut in addition to the cellulolytic flagellates and termite's own cellulases. SIGNIFICANCE AND IMPACT OF THE STUDY: The impact of bacteria on cellulose degradation in the termite gut has always been a matter of debate. In the present survey we investigated the aerobic and facultatively anaerobic cellulolytic bacteria in the termite gut.

Aerobiosis↗

PubMed2003

Nymphs of the Oriental cockroach (Blatta orientalis) as passive vectors of causal agents of avian tuberculosis and paratuberculosis.

The potential transmission of the causal agent of paratuberculosis Mycobacterium avium ssp. paratuberculosis and avian tuberculosis Mycobacterium avium ssp. avium (Actinomycetales: Mycobacteriaceae) by nymphs of the Oriental cockroach Blatta orientalis L. (Blattodea: Blattidae) was investigated by oral infection with mycobacterial suspensions and examination of their droppings and bodies. Both the subspecies of M. avium were isolated from droppings at 3 days post-infection and M. a. avium was found in homogenized bodies at 10 days post-infection. The identity of M. a. avium and M. a. paratuberculosis isolates was demonstrated by Restriction Fragment Length Polymorphism (RFLP) analysis. The M. a. avium isolate used as the inoculum and the isolates from the bodies and droppings of the nymphs were shown to be virulent in chickens. The results show that orally infected nymphs of B. orientalis can harbour and shed viable and virulent mycobacteria. This hazard should be considered in the implementation of control measures against mycobacterial infections of animals and humans, which should include destruction of all developmental stages of cockroaches and prevention of their access to materials that can be contaminated by mycobacteria.

Animals↗