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PubMedDate not supplied

[Modeling of dynamics of microorganisms quantity in the soil polluted by heavy metals].

Microflora of soils polluted by heavy metals was the subject of monitoring investigations. Basing on the experimental data obtained with the use of interactive system ASTRID by the method of group accounting of arguments, mathematical models were constructed which describe the dynamics of microorganisms quantity, depending on the number of ecological factors and presence of heavy metals in the soil. The models allow one to predict the number of microorganisms in the soil under certain parameters of the environment, to determine "critical" deviations from the predicted values as well as to renew the intermediate data for obtaining uniform series of ecological researches. Prospects of the use of the inductive approach for modeling of microbiological processes in the soil have been demonstrated.

Environmental Monitoring↗

PubMed2002

Isolation and characterization of the ethynylestradiol-biodegrading microorganism Fusarium proliferatum strain HNS-1.

We cultivated hundreds of sediment, soil, and manure samples taken from rivers and farms in a medium containing ethynylestradiol (EE2) as the sole source of carbon, so that microorganisms in the samples would acclimatize to the presence of EE2. Finally, we isolated an EE2-degrading microorganism, designated as strain HNS-1, from a cowshed sample. Based on its partial nucleotide sequence (563 bp) of the 28S rRNA gene, strain HNS-1 was identified as Fusarium proliferatum. Over 15 days, F. proliferatum strain HNS-1 removed 97% of EE2 at an initial concentration of 25 mg.L-1, with a first-order rate constant of 0.6 d-1. Unknown products of EE2 degradation, which may be more polar compounds that have a phenolic group, remained in the culture medium.

Agriculture↗

PubMed2002

Antibiotic susceptibility of microorganisms at a general hospital in Lagos, Nigeria.

OBJECTIVE: To determine susceptibility patterns of microorganisms to antibiotics in a large general hospital in Lagos, Nigeria. METHODS: Clinical samples received in the laboratory were processed according to standard methods. Susceptibility to antibiotics was done using a disk diffusion technique. RESULTS: Five hundred and fifty-one samples from urine, wound, reproductive tract and other body fluids were analysed. The most frequently isolated pathogens (n=586) were Staphylococcus aureus, Escherichia coli and Klebsiella pneumoniae. Most of the organisms were sensitive to ciprofloxacin, perfloxacin, cefuroxime, ceftriaxone and azithromycin but were resistant to ampicillin, cotrimoxazole and penicillin. Pseudomonas aeruginosa was multi-resistant. The susceptibility pattern obtained at this hospital is similar to what obtains in teaching hospitals in Nigeria. CONCLUSION: Microorganisms isolated at this hospital are more sensitive to newer antibiotics.

Adult↗

PubMed2002

[The microorganisms associated with bacterial vaginosis as a cause of tubal sterility].

Bacterial vaginosis is one of the most widespread disturbances of the normal state of the vagina of women of reproductive and menopausal age. This condition is highly disregarded due to its moderate and not always clear clinical manifestation. The disturbed proportion of microorganisms in vagina is shown in the strong decrease or lack of lactobacilli and a spread of associated with bacterial vaginosis microorganisms. G. vaginalis, Mobiluncis spp., Bacteroides spp. (without B. fragilis), Peptostreptococcus spp., Mycoplasma hominis, Ureaplasma urealyticum. The condition is a predisposition to a disturbance of natural defense mechanisms and to a spread of infectious agents towards the upper female genital tract. This is a predisposition for the development of tubal patency and motility disorders, ovarian function disturbances, endometrites. The treatment of this condition as an important step in female sterility prophylaxis is commented.

Bacteria, Anaerobic↗

PubMedDate not supplied

[Characteristics of microorganisms colonizing human intestine].

Introduction of novel methods of microbial diagnostics has considerably broadened our conceptions on the qualitative and quantitative variety of microorganisms inhabiting human gastrointestinal tract. In this review morphological and functional properties of obligate anaerobic bacteria (bifidobacteria, lactobacilli, eubacteria, peptostreptococci, clostridia, bacteroids, fusobacteria) and facultative anaerobic microorganisms (enterobacteria, staphylococci, streptococci, yeast-like fungi of the genus Candida) capable of colonizing human intestine are briefly characterized.

Bacteria, Anaerobic↗

PubMed1999

[Detecting microorganisms in soil by PCR and molecular hybridization].

PCR and molecular hybridization provide new methods to detect microorganisms in environment. A simple, sensitive protocol was developed to detect Bacillus thuringiensis HD-1 in soil by PCR and Southern Blotting in this study. Methods of extracting DNA from soil and purification were compared. By a modified total DNA extraction from soil and purification, followed by PCR and Southern Blotting, strain HD-1 released into soil can be detected with a sensitivity of 2.2 x 10(2) cells/g soil. By using other specific primers, this detection protocol can be widely used in the research of ecology and risk assessment of genetically engineered microorganisms released into environment.

Bacillus thuringiensis↗

PubMed2002

[The solubilization of four insoluble phosphates by some microorganisms].

Four insoluble phosphates of ferric phosphate (Fe-P), aluminum phosphate (Al-P), fluorapatite (FAP) and rock phosphate (RP) were used as a sole phosphorus resource for some phosphate-solubilizing microorganisms. It was found that there was significant difference in solubilizing these phosphates by the tested isolates. The fungi normally were more powerful than the bacteria in dissolving the phsophates. The microorganisms generally solubilized more phosphate when supplied with NO3- than with NH4+. However, the isolates of 2TCiF2 and 4TCiF6 had much higher capacity to solubilize FAP and Al-P respectively in NH4+ medium. Most of the isolates solubilized readily FAP and RP, and then Al-P. Ferric phosphate was the least soluble to these isolates. Only isolate 2TCiF2 showed strong ability to solubilize Fe-P. In particular, two Aspergillus sp. had much higher capacity of dissolving Fe-P when suppled with NO3-. The isolates of Evwinia sp. 4TCRi22 and Enterobacter sp. 1TCRi15 had higher capacity of solubilizing FAP. But two Arthrobacter sp. showed the highest activity in RP medium. It is supposed that complexion of organic acids with metals may be the main reason for these isolates to solubilize the phosphates. However, other chelant substances may be much more important for Enterobacter sp. and Erwinia sp. to release phosphorus from the phsphates.

Aluminum Compounds↗

PubMedDate not supplied

[Study of ron-manganese microorganisms by the overgrowth technic].

Microorganisms were studied by capillary microscopy in the surface layer of ooze and in the bottom layer of water in the ore field of the lake Krasnoye. The lake overgrowing of iron-maganese organisms differ from that in the second ooze profile. The growth of the iron-maganese microorganisms on Euglena was found, and the character of their relationship is discussed.

Bacteria↗

PubMedDate not supplied

[Isolation from the environment of strains of microorganisms with glucose oxidase activity].

Strains of microorganisms (13) producing enzyme glucoseoxidase were isolated from various samples of soil. The ability to oxidase glucose in presence of oxygen is most expressed in representatives of genera Aureobasidium, Aspergillus, Penicillium. Media containing the KJ-starch indicator were used at primary step for isolation of microorganisms from the environment. The strain, identified as Aureobasidium pullulans (de Bary) Arnaud, isolated from soil had the greatest glucoseoxidase activity, remained active after lyophilization, grew on the medium, which contained low concentration of glucose and nitrate for candides. Use of its cells as a glucoseoxidase sensor control allowed to detect glucose in the liquids with concentration from 0.027 mM/l.

Aspergillus↗

PubMedDate not supplied

Enumeration of total aerobic microorganisms in foods by SimPlate Total Plate Count-Color Indicator methods and conventional culture methods: collaborative study.

The relative efficacy of the SimPlate Total Plate Count-Color Indicator (TPC-CI) method (SimPlate 35 degrees C) was compared with the AOAC Official Method 966.23 (AOAC 35 degrees C) for enumeration of total aerobic microorganisms in foods. The SimPlate TPC-CI method, incubated at 30 degrees C (SimPlate 30 degrees C), was also compared with the International Organization for Standardization (ISO) 4833 method (ISO 30 degrees C). Six food types were analyzed: ground black pepper, flour, nut meats, frozen hamburger patties, frozen fruits, and fresh vegetables. All foods tested were naturally contaminated. Nineteen laboratories throughout North America and Europe participated in the study. Three method comparisons were conducted. In general, there was <0.3 mean log count difference in recovery among the SimPlate methods and their corresponding reference methods. Mean log counts between the 2 reference methods were also very similar. Repeatability (Sr) and reproducibility (SR) standard deviations were similar among the 3 method comparisons. The SimPlate method (35 degrees C) and the AOAC method were comparable for enumerating total aerobic microorganisms in foods. Similarly, the SimPlate method (30 degrees C) was comparable to the ISO method when samples were prepared and incubated according to the ISO method.

Bacteria, Aerobic↗

PubMed2003

Mining microorganism EST databases in the quest for new proteins.

Microorganisms with large genomes are commonly the subjects of single-round partial sequencing of cDNA, generating expressed sequence tags (ESTs). Usually there is a great distance between gene discovery by EST projects and submission of amino acid sequences to public databases. We analyzed the relationship between available ESTs and protein sequences and used the sequences available in the secondary database, clusters of orthologous groups (COG), to investigate ESTs from eight microorganisms of medical and/or economic relevance, selecting for candidate ESTs that may be further pursued for protein characterization. The organisms chosen were Paracoccidioides brasiliensis, Dictyostelium discoideum, Fusarium graminearum, Plasmodium yoelii, Magnaporthe grisea, Emericella nidulans, Chlamydomonas reinhardtii and Eimeria tenella, which have more than 10,000 ESTs available in dbEST. A total of 77,114 protein sequences from COG were used, corresponding to 3,201 distinct genes. At least 212 of these were capable of identifying candidate ESTs for further studies (E. tenella). This number was extended to over 700 candidate ESTs (C. reinhardtii, F. graminearum). Remarkably, even the organism that presents the highest number of ESTs corresponding to known proteins, P. yoelii, showed a considerable number of candidate ESTs for protein characterization (477). For some organisms, such as P. brasiliensis, M. grisea and F. graminearum, bioinformatics has allowed for automatic annotation of up to about 20% of the ESTs that did not correspond to proteins already characterized in the organism. In conclusion, 4093 ESTs from these eight organisms that are homologous to COG genes were selected as candidates for protein characterization.

Animals↗

PubMed1992

Genes for the biosynthesis of beta-lactam compounds in microorganisms.

Rapid progress has recently been made in the characterization of genes and gene clusters involved in the biosynthesis of beta-lactam antibiotics such as penicillins, cephalosporins and cephamycins. The biosynthetic pathways are found in a wide range of microorganisms, including fungi, actinomycetes and Gram-negative bacteria. Comparisons of gene sequences (particularly the genes encoding isopenicillin N synthetase) and gene organization in these different microorganisms have led to proposals about the evolution of this group of pathways, and how they might have been transferred from prokaryotes to eukaryotes. The isolation and characterization of the genes encoding ACV (tripeptide) synthetase, the first step in the beta-lactam biosynthetic pathway, have revealed the presence of three partly repeated domains, most likely responsible for the recognition, adenylation and activation of the three amino acid precursors of the penams and cephems. This has confirmed their classification as peptide synthetases, distantly related to enzymes responsible for the synthesis of peptide antibiotics in Bacillus brevis and other bacteria and fungi.

Actinomycetaceae↗

PubMed1976

Role of microorganisms in dandruff.

The role of microorganisms in dandruff was studied, by suppressing individually and then collectively the three major components of the scalp microflora. The effect on dandruff was assessed subjectively by clinical grading and objectively by the corneocyte count. No effect on dandruff was demonstrated when scalp organisms were suppressed. In the second group of experiments, dandruff was suppressed by selenium sulfide shampooling and the effect of continued suppression of Pityrosporum with topically applied amphotericin was measured. According to our criteria, dandruff returned to pretreatment levels, despite continued suppression of Pityrosporum. The studies demonstrate that the increased number of scalp microorganisms found in dandruff occurs as a secondary event to increased nutrients and that scalp organisms play no primary role in the pathogenesis of dandruff.

Amphotericin B↗

PubMedDate not supplied

[Glutamine metabolism by rumen microorganisms: effect of monensin].

Transformation of glutamine of mixed population of microorganisms-symbionts is demonstrated. Protection of glutamine and its intermediates (glutamate and pyroglutamate) under the influence of ionophore (monensin) is found. It is accompanied by the reduced (by 30-70 per cent and more) levels of ammonia formation, total VFA, acetate, butyrate, pH, alpha-ketoglutarate dehydrogenase and glutamine synthetase at parallel increase of L-aspartate and L-alanine: 2-oxoglutarate, aminotransferase activity, redox potential of stability of protein content. It is suggested that the rapid change of Eh level on the 24th hour of incubation reflects the main stage of pyroglutamate formation being one of the final products of glutamine degradation when monensin is used. Ionophore affects first of all the inhibition of metabolic processes in gram-positive rumen microorganisms.

Acetates↗

PubMedDate not supplied

[Factors that affect transduction in microorganisms].

Data from literature concerning general and specialized transduction in microorganisms are given in the paper. The process of exogenic DNA penetration to the cells of bacteria and participation of protein products of separate phage genes in this process are described. The so-called E-proteins in a set with DNA penetrate through a cell membrane. In phage P22 they are protein products of phage genes 7, 16, 20. In P22 mutants with an altered transducing frequencies (HFT and LFT) the due functions are also coded by the phage genes. It is shown that the process of DNA packing in phages P22, phi 80, lambda and others is genetically determined. The gene transfer frequency depends on UV radiation and the very nature of transducing phages itself. In virulent phages the UV radiation up to inactivation level 95-99% evokes a decrease of their "killer" ability, which is accompanied by an increase of survivability of the formed transductants and, as a result, by enhancement of the transduction transfer frequency. An important role of the transduction analysis for fine mapping of a genome of microorganisms and its significance for practice are shown. A mathematical analysis of the data on cotransduction of linkage markers is presented as such that may be used when determining the value of transduced fragment of a chromosome.

Bacteria↗

PubMedDate not supplied

Hyperoxic condition prevents bacterial translocation and elevation of plasma microorganism components during hemorrhagic shock.

To evaluate the influence of hyperoxic conditions on bacterial translocation (BT) and microorganism components during hemorrhagic shock, rats were divided into a group breathing 100% oxygen and a group breathing room air. The groups were then subjected to hemorrhagic shock. Systemic blood and mesenteric lymph nodes were cultured for BT, and systemic plasma concentrations of microorganism components were measured by the silkworm larvae plasma (SLP) test and the endotoxin test. Hyperoxic conditions prevented both BT and plasma SLP-reactive substance (peptidoglycan and beta-glucan) elevation during hemorrhagic shock. Our findings suggest that hyperoxic treatment might improve host conditions during hemorrhagic shock.

Animals↗

PubMed1976

[Studies on the mechanism of interaction of glutaraldehyde with microorganisms (author's transl)].

The antimicrobial action of glutaraldehyde on Candida lipolytica increases with reagent concentration, pH and duration of contact. The simultaneous study of the size distribution of the particles shows an agglutination of the cells. This result is confirmed by direct observation of the cells by electron microscopy. Cell agglutination also occurs with other microorganisms (Saccharomyces carlsbergensis, Bacillus megaterium, Escherichia coli) and increases their settling rate. The formation of such intercellular bonds seems to confirm the hypothesis of a preferential action of glutaraldehyde on the outer layers of the cells. The effect of pH on the antimicrobial action of glutaraldehyde is accounted for by the fact that this reagent does not act, under neutral and alcaline conditions, as a dialdehyde but as an unsaturated polymer. This mechanism also accounts for various observations made on microorganisms-glutaraldehyde interactions.

Agglutination↗

PubMed2003

[Examination of urogenital tract microorganism infection and antibiotic susceptibility test].

OBJECTIVE: To isolate bacteria, mycoplasma and chlamydia from the urogenital tract, and to determine their antibiotic susceptibility. METHODS: Bacteria, mycoplasma and chlamydia were isolated from the urogenital tract secretion by artifical culture, and their antibiotic susceptibility was detected by disk diffusion. RESULTS: The common microorganisms were S. epidermidis and corynebacberium, and the minority microorganisms were G- bacteria or E. coli. Bacteria were susceptible to amikacin, cephazolin V, rifampin, gentamycin, and docycyclin. CONCLUSION: S. epidermidis and corynebacterium are important pathogens of the urogenital tract infection. Disk susceptibility test can be used to screen the susceptible antibiotic.

Adult↗