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At least 19 recordsLinked to original sources
PubMed1976

[On the effect of particulate airborne substances on various micro-organisms (author's transl)].

Experimental studies on the reaction of micro-organisms on fine-dust filters (type C) and high-efficiency particulate air filters (type R and S) have shown no evidence of a growth of microorganisms. Therefore efforts were aimed at detecting antimicrobial factors which were supposed to exist in the precipitated acidic continental aerosol. With this in mind, air filters from different locations and with service times were extracted in water and the extract was tested for its antimicrobial effects. Die-off rates are used to demonstrate the influence of such extracts with varying concentrations of substances and pH values on bacteria.

Aerosols↗
PubMed1975

The micro-organisms of tsetse flies.

Micro-organisms from tsetse fly mycetomes were maintained in culture, where they were more pleomorphic than in the mycetomes, but were in some cases very similar to those observed in ovaries by other authors. Agglutination tests on the cultured forms indicated in affinity to Rickettsia. They were sensitive to antibiotics introduced by feeding flies on hosts treated with Ampicillin; this reduced the longevity and fecundity of the tsetse flies and appeared to disturb normal digestion of bloodmeals.

Agglutination Tests↗
PubMed1975

[Mycoplasma-like micro-organisms in malignant tumors and non-tumours dermatovenerological diseases. Electron microscopic investigations (author's transl)].

In examination of the ultrastructure of excised tissue and other material from patients with various diseases, principally dermatovenerological affections and with malignant tumors, and in healthy control subjects, patterns suggesting mycoplasma were repeatedly found in certain diseases only. Specific attempts to isolate mycoplasma from the material were made, in which previously patterns of a mycoplasma type had frequently been seen. It was possible to culture mycoplasma-like organisms in vitro from patients with the following diseases: malignant melanoma, mycosis fungoides, prickle cell carcinoma, squamous cell carcinoma, non-specific urethritis, pemphigus erythematosus, panarteritis nodosa and vasculitis allergica cutis.

Adult↗
PubMed1977

Studies on phosphate-solubilizing bacteria in soil and rhizosphere of different plants. I. Occurrence of bacteria, acid producers, and phosphate dissolvers.

Occurrence of bacteria (total), acid producing and phosphate dissolving micro-organisms in soil, rhizosphere, and rizoplane of Egyptian cotton, peas, or maize during their different growth phases was studied. The rhizosphere effects were generally positive and differed according to type of plant, growth phase of each special plant, and type of micro-organism under study. The high densities of bacteria, acid-producers, and phosphate-dissolvers in the rhizoplane samples suggest the conclusion that roots of the studied plants are colonized with these soil micro-organisms. The role of the micro-organism and the mechanism of the noted colonization is not fully understood yet. However, the presence of high numbers of bacteria in the rhizosphere zones of all plants is undoubtedly important, since they may convert organic and inorganic substances into available plant nutrients. The acidproducing organisms were greatly stimulated in the rhizosphere of all plants. Consequently, the production of acid, especially in alkaline soils such as in Egypt, may directly or indirectly react with insoluble inorganic compounds, converting their nutrient elements into available forms for the growing plants. But not all acid-producers are considered as phosphate-dissolvers. Therefore, the presence of high numbers of phosphate-dissolving bacteria in the rhizophere zones may explain how the growing plants can obtain their requirements in such alkaline soils.

Bacteria↗
PubMed2026

Exploring Actinobacteria for new insecticides and their delivery in crop protection.

Crop protection is essential for agricultural production systems, safeguarding yields and product quality. Chemical controls are a mainstay of protection; however, regulatory and consumer demands, environmental concerns and a general overreliance resulting in resistance development in pest populations have led to increased interest in biopesticides and environmentally friendly alternatives. Biopesticides targeting insects include micro-organisms and their derivatives, such as peptides and specialized metabolites. Their target specificity, structural complexity, modes of action and environmental safety are key differentiators to chemical controls, and when used in integrated pest management programmes, biopesticides can reduce reliance on chemical pesticides and promote sustainable agriculture. As the demand for bioinsecticides grows, so too has the research and application of micro-organisms, alongside their taxonomic diversity and isolation sources. Of key interest are Actinobacteria as both promising and well-tested alternatives for managing insect pests in various agricultural settings, with several products commercialized for use across a variety of crops and target pests. Recent advances and investigations in metabolomics and genomics highlight the untapped and significant biochemical potential and value of Actinobacteria for natural product discovery. This review covers a broad spectrum of published literature that has reported on insecticidal biological activity data associated with Actinobacteria or their natural products. We also report on Actinobacteria-derived nematicides and acaricides that are significant for crop protection. The origin of these natural products, their structural diversity and notable substructures are discussed, along with new areas for discovery and avenues for enhancing screening methods and metabolo-genomics approaches.

Insecticides↗
PubMed2026

Complementary activity of an ancient combination of natural ingredients on the dysbiosis symptoms linked to acne.

ETHNOPHARMACOLOGICAL RELEVANCE: Acne is one of the most common dermatologic diseases in the world. It is due to the secretion of a high level of sebum that causes follicular hyperkeratinisation, alterations of the cutaneous microbiota, and inflammatory processes. One of the first-line treatments is still an antibiotic prescription, that inhibits bacterial growth and, as a consequence, lowers some of the other symptoms. Nevertheless, this high level of antibiotic prescription contributes to the increase of antibiotic resistance. Alternatives to antibiotics are thus highly required, as acne does not represent per se an infection. AIM OF THE STUDY: In the frame of the IRGAP (Interdisciplinary Research Group on Ancient Pharmacopeias) consortium, different preparations dedicated to cutaneous ailments have been identified based on ancient traditional uses, dating back to Antiquity or Middle Ages. Among them, the combination of Aloe vera and Myrrh was widely conserved over centuries. Even though this combination is no longer in use, we wondered why this combination was so widely conserved. We considered the use of this combination of ingredients to treat acne, a case study for which both plants are still used, but separately. MATERIALS AND METHODS: The effects of both plant extracts were analyzed on the growth of different bacteria from the skin microbiota, cultivated alone or in co-culture conditions. As the skin is a rather heterologous environment, we further tested the robustness of our study by varying the experimental conditions. We further analyzed any complementary effects of these extracts on the inflammation process linked to acne. RESULTS: We showed that both plant extracts have complementary effects on micro-organisms and on macrophages. Indeed, while Myrrh extracts inhibited the growth of specific skin microbiota bacteria, Aloe vera gel extracts on the opposite, favored the growth of others: the two plants could act in a complementary way to restore a healthy microbiota. Another complementarity was also observed on macrophages: while Myrrh extracts showed an anti-inflammatory effect, Aloe vera gel extracts showed an antioxidant effect. CONCLUSION: Our results highlight the potential of the combination of Myrrh and Aloe vera to address both the dysbiosis of the skin microbiota and the inflammation associated with acne. Thus, this exploration of forgotten combinations from historical pharmacopoeias underscores the importance of revisiting past traditional knowledge as a source of innovation.

Aloe vera↗
PubMed1977

Bacterial stimulation and granulocyte inhibition of granulopoietic factor production.

We attempted to determine the effect of live bacteria (Staphylococcus epidermidis) on granulocyte colony-stimulating-factor production by human peripheral blood mononuclear cells (monocytes and lymphocytes) in vitro. Addition of bacteria to mononuclear-cell cultures enhanced colony-stimulating-factor production by these cells, as assayed on both human and mouse bone marrow. Addition of peripheral blood granulocytes to parallel cultures eliminated this enhancement effect, presumably by bacterial removal or inactivation. These data suggest that micro-organisms may have a pivotal role in granulocyte production and maturation by serving as a stimulus to increase colony-stimulating-factor production and also as negative control through their removal by the newly formed granulocytes.

Animals↗
PubMed1976

Food protein sources.

Work on food, planned by the U.M. (Use and Management) Section of the U.K. committe, was limited to sources of protein because we agreed that more problems calling for research were likely to arise in getting adequate supplies of protein than of other types of food. Deer meat can be produced on land too rough and exposed for sheep; parts of the work on their metabolism and food requirements necessitated building a mobile laboratory. The manner in which the nutritive value of maize is affected by changes in the ratios in which the component proteins are present, stimulated similar studies on barley and groundnut. There is good quality protein in coconuts and leaves but its use in human food is restricted by the presence of fibre. Methods for separating protein from fibre and other deleterious components were improved. In cooperation with scientists in India and Nigeria, the potential yield of protein-deficient foods. e.g. cassava, were 'ennobled' by growing micro-organisms on them with the addition of a cheap source of nitrogen.

Animals↗
PubMed1977

Meiosis in perspective.

Our understanding of meiosis springs from two suggestions made by Weismann in 1887. One was that meiosis would be found to compensate for fertilization in the life cycles of both sexes and all organisms. The other was that the development of sexual reproduction in evolution depended on the value of meiosis in exposing the results of genetic recombination to natural selection. In confirming these propositions we were bound to discover that the properties of meiosis appear both as the causes and the consequences of evolution: it is the hinge on which turns the evolution of breeding method, reproductive habit, life cycle and hereditary structure, that is the genetic system, in all sexually reproducing species of organism. We have had three main fields of attack on our problem. First, there was the natural variation of meiosis including that of two-track hereditary within the species: here, animals took the lead. Secondly, there was the experimental field - both with genetic controls such as polyploidy and the sterilizing mutations of mitosis as well as meiosis, and with physical and chemical controls: here, the higher plants and micro-organisms have given us our great opportunities. Thirdly, we have the widening field where physicochemical knowledge and genetic control converge and collaborate. In all this work we have to be aware that meiosis works with chromosomes which always have the two functions of accomplishing evolution and of implementing its results in heredity. In consequence, the adaptation of meiosis is perpetually imperfect.

Biological Evolution↗
PubMed1977

On the induction of zoosporogenesis in the rumen phycomycetes Neocallimastix frontalis, Piromonas communis and Sphaeromonas communis.

The plant components inducing zoosporogenesis in the rumen phycomycetes Neocallimastix frontalis, Sphaeromonas communis and Piromonas communis were widely distributed in the plant kingdom with no apparent taxonomic relationship. In Lolium perenne L. (perennial rye-grass) and Hordeum distichon (barley), the components were principally present in the leaves and aerial tissues. Sufficient inducer was present in the normal diet of the host animal to trigger the differentiation and release of the zoospores from all the sporangia of each phycomycete species present in the rumen fluid tested. The inducers were unstable to oxygen, especially at elevated temperatures, and were destroyed by rumen micro-organisms. They may be similar compounds for each species.

Animal Feed↗
PubMed2026

Psychrobacter sp. XL111, a novel bacterial species from hadal amphipods: genomic insights into environmental adaptation and biotechnological potential.

The hadal zone presents one of the most extreme environments on Earth. While amphipods dominate this realm, the adaptive mechanisms of their resident gut microbiota are not fully understood, which is essential both for understanding the limits of life and for unlocking novel microbial resources. This study investigates Psychrobacter sp. XL111, a novel bacterial species isolated from the gut of hadal amphipods, to elucidate its survival strategies and biotechnological potential. Pan-genome analysis confirms the high genomic plasticity of this genus and highlights the genomic innovations in genes related to environmental adaptation. Genomic analysis revealed specialized adaptations to the deep-sea niche, including expansions in signal transduction systems, pathways for degrading complex organics and the capacity to synthesize stress-resistant compounds. A notable loss of oligosaccharide transporters alongside an enrichment of glycosyltransferases suggests a distinctive evolutionary reconfiguration of carbohydrate metabolism. Functional characterization confirmed that the strain produces an exopolysaccharide with potent radical-scavenging activity, underscoring a key mechanism for mitigating oxidative stress. Our results position hadal micro-organisms as a valuable source of novel enzymes and bioactive molecules for industrial and biomedical applications.

Animals↗
PubMed1979

A comparative study of the microbiological assays currently available for nystatin raw material.

The classical agar diffusion and turbidimetric methods of assay for nystatin are compared with the more recently documented assays for this antibiotic which depend upon physicochemical measurement of the response of micro-organisms. Liquid nitrogen stored inocula were used throughout. It is concluded that the newer methods of assay are as reproducible and reliable as the agar diffusion and turbidimetric methods and that they are generally more sensitive. The choice between the assay methods compared can thus be based on speed, cost and sample through-put.

Biological Assay↗
PubMed2026

Antibiotic-impregnated bone graft to prevent infection after total hip arthroplasty (ABOGRAFT): protocol for a randomised, double-blind, placebo-controlled trial.

INTRODUCTION: Studies have shown promising results using bone graft as a carrier for local administration of antibiotics to reduce the risk of prosthetic joint infection (PJI). The objective of this clinical trial is to determine if tobramycin and vancomycin-impregnated bone graft is safe and effective in reducing the rate of PJI after total hip arthroplasty (THA). METHODS AND ANALYSIS: This study is an international, randomised, double-blinded, placebo-controlled clinical drug trial. Patients scheduled for THA (n=1100) requiring bone grafting (excluding revisions due to an ongoing infection) are randomised in a 1:1 ratio to prophylactic treatment with tobramycin and vancomycin or placebo-impregnated bone graft.The primary outcome is the time to reoperation due to infection or diagnosis of PJI, expressed as a relative risk difference between the two groups. A risk reduction of at least 50% is considered clinically relevant. Secondary outcomes are time to and reason for reoperation and implant revision, type of micro-organism and antibiotic susceptibility pattern within 2 and 5 years after surgery. Safety outcomes are the number of adverse events and revision rate due to aseptic loosening. The primary analysis will be performed using proportional hazard models. ETHICS AND DISSEMINATION: The study has been approved under the Clinical Trial Regulation No 536/2014 (EU CT; 2024-510921-25-00). Results will be published in open-access peer-reviewed journals and disseminated to patient organisations and the media, and de-identified individual participant data will be curated and shared on reasonable request in accordance with the Findability, Accessibility, Interoperability and Reuse principles, subject to the laws and regulations governing data protection in each participating country. TRIAL REGISTRATION NUMBER: NCT05169229.

Humans↗
PubMed1976

[Determination of the toxicity of industrial waste by means of a bacterial test (author's transl)].

The decision on whether industrial waste should be deposited on general or special dumps depends upon the toxicity of the waste and thus upon the risk of ground-water pollution and the killing off of micro-organisms responsible for breaking down waste products. Since chemical analyses that are to provide information on toxicity are frequently very costly, an attempt was made to determine the toxicity of solid or semi-solid waste with the aid of a bacterial test. As in the perforated-plate test, here, too, the formation and size of inhibition zones were used to determine the toxicity after diffusion of substances contained in industrial waste. About 30 different types of industrial waste were examined with this method. For almost all substances a positive correlation of the (known) constituents of waste to the formation of inhibition zones was found to exist. The influence exercised by solubility and diffusibility and other problems are dealt with.

Hydrogen-Ion Concentration↗
PubMedDate not supplied

[Effect of growth medium composition of glucoamylase and glycosyltransferase activity of Endomyces fibuliger].

Production of glucoamylase and glycosyltransferase by Endomyces fibuliger was found to depend on sources of carbon and nitrogen nutrition. Starch at a concentration above 0.5% in the medium stimulated biosynthesis of glycosyltransferase but inhibited production of glucoamylase by End. fibuliger 20-9. The rate of growth of the micro-organism increased by a factor of 3.3 with an increase of starch concentration from 0.5 to 6%. Synthesis of glycosyltransferase was repressed by glucose, lactose, sucrose and maltose. Synthesis of glucoamylase was repressed by lactose, sorbose and galactose. Synthesis of glycosyltransferase was stimulated by xylose, sorbose and galactose. Production of glucoamylase was stimulated by xylose and arabinose. Growth of the culture and synthesis of glucoamylase and maltase in the cultural broth were stimulated by an increase in the concentration of maize extract. Biosynthesis of glucoamylase and glycosyltransferase was stimulated by NH4H2PO4.

Ascomycota↗
PubMed1977

Leukocyte phagocytic function and dysfunction.

Although some species of bacteria are killed in vitro by humoral factors in cell-free serum, the in vivo experience with leukopenic patients illustrates the critical role played by phagocytic leukocytes in host resistance to infection. Effective ingestion and killing of micro-organisms requires the sequential and integrated function of the elements of the phagocytic system. Each step in the phagocytic process is also a potential crack in the armor of host defense, and an increasing number of clinically significant disorders of phagocytic function are being recognized and described (5). The phagocytic leukocytes are equipped with a variety of intracellular microbicidal mechanisms which provide a degree of overkill capacity and allow these cells to meet the challenges posed by the many and varied microbial transfressors. Undoubtedly, other phagocytic disorders will be discovered and other important aspects of the intraleukocyte killing mechanisms will be elucidated. For instance, little is known about the function of leukocytes within the relatively hypoxic environment of injured tissue where so many bacterial infections begin. As our understanding of phagocytic function develops, new ways may be found to augment host resistance by preservation or stimulation of the phagocytes.

Animals↗
PubMed1976

[Synovial fluid. Review of international literature from 1972 to 1975 (author's transl)].

The tremendous increase in the number of articles from the world scientific literature dealing with the synovial fluid in recent years, reflects the growing interest of research on that subject. The current review summarizes the scientific works published during the period of 1972 to 1975. This review deals with fundamental as well as applied research or clinical reports adding some diagnostic hints in the knowledge of diseases involving joints. The content of the review is divided in two major chapters. 1) The Physico-Chemical Properties of the Synovial Fluid (viscosity, pH,...); 2) The Composition of the Synovial Fluid (proteins, carbohydrates, lipids, prostaglandins, cells, crystals, micro-organisms).

Antibodies, Antinuclear↗