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PubMed1997

Pneumonia with serological evidence of acute infection with the Chlamydia-like microorganism "Z".

"Z" is a recently discovered microorganism that may belong to a new genus in the family Chlamydiaceae. Using an ELISA test we developed, we measured levels of serum antibody against "Z" for 308 paired sera obtained from adult patients hospitalized with community-acquired pneumonia (CAP). In 114 patients (37%), serological evidence of past infection with "Z" was found. In eight patients (2.6%) there was serological evidence of acute infection with this pathogen. In four of these eight patients, no other pathogen for CAP was identified despite an intensive serological investigation encompassing 13 etiological agents. The four patients were about 30 yr old, and three of them had no history of chronic illness. Their illness was characterized by high fever, a nonproductive cough, gastrointestinal symptoms, a shift to the left in the white blood cell count, and a prompt, dramatic response to erythromycin therapy. We conclude that the microorganism "Z", or a close variant, is infectious for humans, in some cases causing CAP. In these cases the disease is mild and responds quickly to treatment with erythromycin.

Acute Disease↗
PubMed1981

Calcifiability comparison among selected microorganisms.

Seven ATCC strains of bacteria were examined for apatite formation in a chemically-defined calcification-supporting medium and also in a metastable calcium phosphate solution. One, E. coli, calcified in both. One, S. aureus, calcified in the solution, but not in the medium. The other five did not calcify in either. The results substantiate the belief that calcification is restricted to certain microorganisms. However, they do not rule out the possibility that a noncalcifiable microorganism has the potential to calcify, and the activity is prevented by a cell component. Additionally, the findings emphasize that determining microbiologic calcifiability only in a calcification-supporting culture medium is inadequate. In culture, an efficient calcium pump might preclude calcification by establishing a cytoplasmic calcium level too low for nucleation activation. Calcifiability assays should be done by incubating minimally-metabolizing freeze-dried cells in metastable calcium phosphate solution.

Apatites↗
PubMed1982

Plasmid content of some oral microorganisms isolated from subgingival plaque.

Eighty-five strains of bacterial species selected from the predominant cultivable dental plaque flora of patients with different periodontal pathologies were examined for their plasmid content. Microorganisms studied included: Actinomyces viscosus, A. odontolyticus, Bacteroides asaccharolyticus (B. gingivalis), B. melaninogenicus subspecies intermedius, and subspecies melaninogenicus, Capnocytophaga ochracea (B. ochraceus), and Fusobacterium nucleatum. Three B. melaninogenicus isolates showed plasmids of approximately 2.7-2.9 Mdalton (mega-dalton) molecular size. Restriction enzyme digests of the plasmids demonstrated dissimilar patterns when electrophoresed on agarose gels. In other microorganisms, including the Actinomyces species, plasmids were not observed.

Actinomyces↗
PubMed2003

A high-throughput amenable colorimetric assay for enantioselective screening of nitrilase-producing microorganisms using pH sensitive indicators.

Based on the color change of an indicator due to the release of hydrogen ion from a nitrilase-catalyzed reaction, a rapid colorimetric method was established for the enantioselective screening of nitrilase-producing microorganisms. The formation of acids due to the nitrilase-mediated hydrolysis of nitriles causes a drop in the pH, which in turn results in a change of color of the solution (containing indicator) that can be observed visually. The buffer (0.01 M phosphate, pH 7.2) and indicator (Bromothymol blue, 0.01%) were selected in such a way that both have the same affinity for the released protons. The enantioselectivity of nitrilases was estimated by comparing the hydrolysis of (R)-mandelonitrile with that of racemate under the same conditions. The method was used to screen a library of nitrilase-producing microorganisms, isolated in the authors' laboratory for their ability to enantioselectively hydrolyze mandelonitrile to mandelic acid, an important chiral building block.

Acetonitriles↗
PubMed2002

The diversity of microorganisms associated with Acromyrmex leafcutter ants.

BACKGROUND: Molecular biological techniques are dramatically changing our view of microbial diversity in almost any environment that has so far been investigated. This study presents a systematic survey of the microbial diversity associated with a population of Acromyrmex leafcutter ants. In contrast to previous studies on social insects, which targeted specific groups of symbionts occurring in the gut (termites, Tetraponera ants) or in specialised cells (Camponotus ants) the objective of our present study was to do a total screening of all possible micro-organisms that can be found inside the bodies of these leafcutter ants. RESULTS: We amplified, cloned and sequenced SSU rRNA encoding gene fragments from 9 microbial groups known to have insect-associated representatives, and show that: (1) representatives of 5 out of 9 tested groups are present, (2) mostly several strains per group are present, adding up to a total of 33 different taxa. We present the microbial taxa associated with Acromymex ants in a phylogenetic context (using sequences from GenBank) to assess and illustrate to which known microorganisms they are closely related. The observed microbial diversity is discussed in the light of present knowledge on the evolutionary history of Acromyrmex leafcutter ants and their known mutualistic and parasitic symbionts. CONCLUSIONS: The major merits of the screening approach documented here is its high sensitivity and specificity, which allowed us to identify several microorganisms that are promising candidates for further study of their interactions with Acromyrmex leafcutter ants or their gardens.

Animals↗
PubMed1984

Neutrophil bactericidal dysfunction towards oxidant radical-sensitive microorganisms during experimental iron deficiency.

We developed a clear-cut nutritional iron deficiency anemia without concomittant malnutrition in rats given a low iron diet, and we restored normal iron and hemoglobin levels in these same animals with iron dextran injections. The neutrophil function studies performed during and after a period of iron deficiency showed the following: Phagocytosis of Staphylococcus aureus 502A, Streptococcus pneumoniae, and Salmonella typhimurium was not altered by iron deficiency or by the administration of iron; phagocytosis of Candida albicans was moderately abnormal during iron deficiency, and became normal with the restoration of iron sufficiency. Microbicidal activity towards Staphylococcus aureus 502A and Candida albicans, two catalase-positive microorganisms, was markedly decreased (to 50% of control values) and returned to normal when iron sufficiency was restored. Killing of a catalase-negative organism, Streptococcus pneumoniae was normal in iron-deficient rats. This pattern of differential bactericidal activities suggested an abnormality of the oxidant radical-generating machinery in neutrophils of iron-deficient animals. Indeed, iron deficiency caused a marked decrease of neutrophil nitroblue tetrazolium dye reduction, which disappeared after iron administration. Neutrophil myeloperoxidase activity was slightly decreased in iron deficient rats and returned to normal after iron administration. Microbicidal activity towards a gram-negative, catalase-positive organism, Salmonella typhimurium, was equal in iron deficient and iron sufficient animals. Our combined results suggest that a definite microbicidal defect is the consequence of nutritional iron deficiency, apart from any protein-calorie malnutrition. This defect affects the disposal in PMNs of two catalase-positive microorganisms (which require intracellular production of oxidant radicals for their destruction) but not of a catalase-negative bacterial species.(ABSTRACT TRUNCATED AT 250 WORDS)

Anemia, Hypochromic↗
PubMed2003

Prepared endotracheal tubes: are they a potential source for pathogenic microorganisms?

UNLABELLED: Prepared endotracheal tubes (PETTs) are frequently used for unanticipated difficult intubation, but their storage time is highly variable and institution-dependent. We sought to determine first, if open, unused PETTs are a potential source of pathogenic microorganisms, and second, if PETTs can provide a medium for bacterial survival after deliberate contamination. A stylet was inserted into a 7-mm ETT, and this system was ethylene oxide sterilized. The PETTs were placed in 20 different locations and sampled 8 times in a 4-wk period. Growth was determined after 48-h incubation, and the microorganism was identified. In Phase 2, the PETT (n = 40) was swabbed with a fresh suspension of H. influenzae, Pseudomonas aeruginosa, Staphylococcus aureus, Enterococcus faecium, or a negative control. Nonvirulent bacteria were cultured from 13 of 160 (8.1%) samples and from 15 of 320 (4.7%) samples in Phases 1 and 2, respectively. No PETT grew the same bacteria more than once. In Phase 2, after 24 h, only E. faecium was recovered. Based on this study, the pathogenic potential of PETTs is very small, and they can be safely used for up to 1 mo. This practice could translate to significant cost reduction for operating room budgets. IMPLICATIONS: Prepared endotracheal tubes (PETTs) are back-up airway equipment to be used in the case of a difficult intubation. A short PETT shelf life because of unknown safe storage time results in significant budget costs. This blinded, controlled study examined the pathogenic potential of PETTs in the operating room environment.

Bacteria↗
PubMed1995

Metabolism of peptide drugs by the microorganisms in rat cecal contents.

The metabolism of insulin and calcitonin by microorganisms was examined in rat cecal contents. Both insulin and calcitonin were markedly degraded. Calcitonin was more susceptible to proteolysis in rat cecal contents than insulin. Calcitonin was also rapidly degraded in supernatant, while we found few degradation products of insulin. These findings suggest that care should be taken to metabolize the peptide drugs by microorganisms when they are administered to the large intestine for colon-specific drug delivery.

Animals↗
PubMed1975

Phase maps for particles and microorganisms in animal quarters.

Measurements of fallout of particles and microorganisms were carried out during the light and dark period in animal rooms occupied by rats, rabbits, cats and monkeys. Correlations between both parameters were established. The 24-hour mean was calculated and the percentage deviation of the individual measurements from this mean used for the elaboration of phase maps. For rats there is a high increase of particle and microorganism emission during the night following the activity cycle, while for cats and monkeys emission increases only during the feeding period. In rabbit rooms there is a nearly equal emission during day and night.

Air Microbiology↗
PubMed2006

Subsurface biobarrier formation by microorganism injection for contaminant plume control.

The concept of an in situ mixture of residual soil and aerobic microorganisms as a biobarrier for controlling contaminant plume was evaluated in this study. Azotobacter chroococcum was inoculated into soil with oxygen as the electron acceptor and appropriate substrate to induce biofilm clog soil pores. The hydraulic conductivity of soil decreased by 1/8000 while substrate and oxygen were provided to the injected microorganism, and increased by 400% when no substrate was provided. A series of column experiments were carried out to measure the hydraulic conductivity of soil specimens. The results showed that the highest hydraulic conductivity reduction occurred when the substrate and electron acceptors were first introduced, and this reduction increased toward the outlet of the column. The substrate was consumed mostly at the inlet and was distributed with time. The analysis of volatile substances after the test showed that the inlet had a high organic content and the outlet had a low organic content.

Azotobacter↗
PubMed1999

Effects of DFA IV in rats: calcium absorption and metabolism of DFA IV by intestinal microorganisms.

Di-D-fructose-2,6':6,2'-dianhydride (DFA IV) is a disaccharide consisting of two fructose residues that can be prepared from levan by levan fructotransferase from Arthrobacter nicotinovorans GS-9, and it can be expected to have novel physiological functions from its unique structure. In this study, the effects of DFA IV on calcium absorption and the metabolism of DFA IV by intestinal microorganisms were studied in rats to examine the physiological functions of DFA IV. The apparent calcium absorption in rats fed with DFA IV was significantly higher than that in the control rats, and it seems that calcium absorption had almost been completed at the end of the small intestine. DFA IV also increased the calcium absorption in in vitro experiments, using everted jejunal and ileal sacs, and this result supports the finding obtained in the in vivo experiments. These results indicate that DFA IV may have a function for increasing the calcium absorption in the small intestine of rats. However, the effect in the large intestine could not be clearly observed because of the lack of calcium that reached there. The results of analyses of organic acids in the cecal and colonic contents and of DFA IV in the fecal, cecal, and colonic contents showed that the metabolism of DFA IV by microorganisms in the large intestine progressed gradually, and that DFA IV was converted mainly to acetate, butyrate, and lactate.

Animals↗
PubMed2004

Distribution of Prx-linked hydroperoxide reductase activity among microorganisms.

Peroxiredoxin (Prx) constitutes a large family of enzymes found in microorganisms, animals, and plants, but the detection of the activities of Prx-linked hydroperoxide reductases (peroxiredoxin reductases) in cell extracts, and the purification based on peroxide reductase activity, have only been done in bacteria and Trypanosomatidae. A peroxiredoxin reductase (NADH oxidase) from a bacterium, Amphibacillus, displayed only poor activities in the presence of purified Prx from Saccharomyces or Synechocystis, while it is highly active in the presence of bacterial Prx. These results suggested that an enzyme system different from that in bacteria might exist for the reduction of Prx in yeast and cyanobacteria. Prx-linked hydroperoxide reductase activities were detected in cell extracts of Saccharomyces, Synechocystis, and Chlorella, and the enzyme activities of Saccharomyces and Chlorella were induced under vigorously aerated culture conditions and intensive light exposure conditions, respectively. Partial purification of Prx-linked peroxidase from the induced yeast cells indicated that the Prx-linked peroxidase system consists of two protein components, namely, thioredoxin and thioredoxin reductase. This finding is consistent with the previous report on its purification based on its protein protection activity against oxidation [Chae et al., J. Biol. Chem., 269, 27670-27678 (1994)]. In this study we have confirmed that Prx-linked peroxidase activity are widely distributed, not only in bacteria species and Trypanosomatidae, but also in yeast and photosynthetic microorganisms, and showed reconstitution of the activity from partially purified interspecies components.

Animals↗
PubMed2005

Production of hydroxycitric acid by microorganisms.

Hydroxycitric acid (HCA) is a major acid component of the tropical plants Garcinia cambogia and Hibiscus subdariffa. (2S,3S)-HCA from G. cambogia was shown to be a potent inhibitor of ATP citrate lyase (EC4.1.3.8), which catalyzes the extramitochondrial cleavage of citrate to oxaloacetate and acetyl-CoA. (2S,3R)-HCA from H. subdariffa inhibits alpha-amylase and alpha-glucosidase, leading to reduction of carbohydrate metabolism. The availability of HCA is limited by the restricted habitat of the plants as well as the difficulty of stereoselective organic synthesis. Hence, we screened microorganisms producing HCA to find an alternative source of optically pure bulk HCA. Two strains, Streptomyces sp. U121 and Bacillus megaterium G45C, were screened by HPLC analysis. Particular metabolites were purified from their culture broths and compared with authentic HCA from plants. NMR studies indicated that the products are identical to Hibiscus-type HCA. This is the first report showing isolation of microorganisms producing HCA.

Bacillus megaterium↗
PubMed2006

Production of (R)-3-amino-3-phenylpropionic acid and (S)-3-amino-3-phenylpropionic acid from (R,S)-N-acetyl-3-amino-3-phenylpropionic acid using microorganisms having enantiomer-specific amidohydrolyzing activity.

(R)-3-Amino-3-phenylpropionic acid ((R)-beta-Phe) and (S)-3-amino-3-phenylpropionic acid ((S)-beta-Phe) are key compounds on account of their use as intermediates in synthesizing pharmaceuticals. Enantiomerically pure non-natural amino acids are generally prepared by enzymatic resolution of the racemic N-acetyl form, but despite the intense efforts this method could not be used for preparing enantiomerically pure beta-Phe, because the effective enzyme had not been found. Therefore, screening for microorganisms capable of amidohydrolyzing (R,S)-N-acetyl-3-amino-3-phenylpropionic acid ((R,S)-N-Ac-beta-Phe) in an enantiomer-specific manner was performed. A microorganism having (R)-enantiomer-specific amidohydrolyzing activity and another having both (R)-enantiomer- and (S)-enantiomer-specific amidohydrolyzing activities were obtained from soil samples. Using 16S rDNA analysis, the former organism was identified as Variovorax sp., and the latter as Burkholderia sp. Using these organisms, enantiomerically pure (R)-beta-Phe (>99.5% ee) and (S)-beta-Phe (>99.5% ee) with a high molar conversion yield (67%-96%) were obtained from the racemic substrate.

Cell-Free System↗
PubMed1994

Screening and Separation of Microorganisms Degrading PCBs.

We performed an assay to assess the polychlorinated biphenyl (PCB) degradative capability and congener specificity of aerobic microorganisms. Microbial strains were isolated and separated from different types of soils in the Czech Republic, and their PCB-degrading abilities were compared. An industrial mixture of PCB congeners ranging from dichloro- to hexachlorobiphenyl and representing various chlorination patterns was used throughout. The PCB degradative ability of microorganisms was determined by gas chromatography after 7 days of incubation. The degree of degradation was found to depend on the number of chlorine substituents.

Journal Article↗
PubMedDate not supplied

Review and discussion of the body's normal microorganisms.

Nurses need to be constantly vigilant in their hygiene practices, yet not ignore the role of normal microbes in the maintenance of health: we have more microorganisms living on us and in us than any other type of cell, and they have a role in preventing colonisation by harmful pathogens, and also in regulating the immune system. This article reviews the types of microorganisms normally found in and on individuals, and how these can contribute to health.

Health Promotion↗
PubMed1993

Exposure to microorganisms associated with allergic alveolitis and febrile reactions to mold dust in farmers.

STUDY OBJECTIVE: To compare exposure to microorganisms associated with allergic alveolitis (AA) and with febrile reactions to inhaled mold dust (organic dust toxic syndrome [ODTS]) in farmers and in normal subjects. DESIGN: A prospective study in which exposure was evaluated within two weeks of medical consultation for AA or ODTS. Samples were collected during normal farming (background) and during the handling of materials associated with disease or causing maximal exposure in reference farms (worst case). SETTING: Swedish farms PARTICIPANTS: Eleven farmers with a confirmed diagnosis of AA from ten farms, 16 subjects with symptoms of ODTS from 12 farms, and 17 reference farmers. MEASUREMENTS AND RESULTS: Worst-case samples representative of the exposure preceding disease were obtained on four farms where five farmers had had AA; the samples contained on average 2.6 +/- 1.8 x 10(9) (SD) spores/m3 of air. On six farms where nine farmers had had ODTS, representative samples averaged 13 +/- 13 x 10(9) spores/m3, and on reference farms this figure was 0.12 +/- 0.20 x 10(9) spores/m3. The daily spore dose associated with allergic alveolitis was 2 x 10(9) spores/d, which was ten times higher than on reference farms. The average dose associated with ODTS was 2 x 10(10) spores. Worst-case samples, collected during 10 to 30 min, contributed to more than 90 percent of the day exposure on farms where AA or ODTS had occurred. CONCLUSION: Allergic alveolitis was associated with high exposure levels on most weekdays for weeks, and ODTS was associated with extreme exposure occurring on a single day. There was no correlation with individual spore types and disease and the present results are compatible with a hypothesis that common cell wall components of microorganisms may cause "toxic" symptoms and stimulate immune reactions.

Adult↗
PubMed2004

Nontraditional method of evaluating disinfectants: with isolated microorganisms from the food factory.

Cleaning and disinfection in the food industry are critical in the production process, and the efficacy of the disinfectants used is frequently debated. Several factors are involved in the effectiveness of a disinfectant agent. It is important to consider the number and type of microorganism present as well as the physical and chemical characteristics of the water; these factors vary from industry to industry and they determine efficacious disinfection. In the laboratory it is possible to evaluate disinfectants to be used in a particular factory, even though these are different from those reported by international organizations. Some useful practices are: 1. To use cultures of microorganisms isolated in one's own lab instead of reference cultures. 2. To use as a diluter the water that is used daily in the factory under question. 3. To compare different disinfectant products under identical conditions of time and temperature.

Disinfectants↗