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At least 631 records · Page 35Linked to original sources
PubMed1995

[Ecologic impact of antibiotherapy. Role of substitution microorganisms in the control of antibiotic-related diarrhea and colitis].

Mild or severe episodes of diarrhoea are the main side effects of antibiotic therapy. The major form of intestinal disorders is pseudomembranous colitis due to Cl. difficile. Among ecological means for control of these diarrhoea, which result from disruption of the intestinal ecosystem, several non-pathogenic microorganisms can be used in order to establish a new equilibrium; among the available microorganisms, S. boulardii is a non-pathogenic yeast, which has given rise to many experimental and clinical studies. Moreover, results of an in vitro study of susceptibilities to antibiotics of the available microorganisms are reported; for S. boulardii, these in vitro data confirm the bases of persistence of the organism in the gut during antibiotic therapy. Besides these in vitro data, experimental studies in animal models (gnotobiotic mice and hamsters with Cl. difficile colitis) have confirmed the potential effectiveness of S. boulardii in preventing the pathogenic effect of toxins A and B and in decreasing numbers of Cl. difficile colonies in the gut. Similarly, in intensive care unit patients, controlled prospective studies have shown that administration of S. boulardii prevented diarrhoea, pseudo-membranous colitis and intestinal translocation of gram-negative bacilli when combined with selective digestive decontamination.

Animals↗
PubMed1994

Incorporation of body components of diverse microorganisms by larval mosquitoes.

A pulse-purge schedule of exposure to labeled microorganisms was used to compare their digestibility by larval mosquitoes. Larvae were placed for an hour in suspensions of diverse axenically grown microorganisms that had been labeled with radioactive carbon (in the form of glucose or glycine). The guts of these mosquitoes were then purged with nonlabeled Sephadex particles for 30 min, and retained radioactivity was measured. Larvae imbibed no dissolved material. Larval mosquitoes differ in their capacity to derive label from algae (sensu lato), and certain algae contribute more label to these mosquitoes than do others. The nature of any algal food, as well as the feeding habits and developmental stage of the larva, influence its capacity to derive label from algae. This pulse-purge method of analysis can assist in the selection of algal "vectors" suitable as vehicles for transgenic larvicide. Although larval mosquitoes fail to assimilate the contents of Palmellacoccus cells with which they are confined, as much as 1/3 of the body contents of a Euglena gracilis cells become incorporated into their bodies. Because larval mosquitoes internalize more material from Euglena than they do from various other algae, these microorganisms provide a promising candidate vehicle for transgenic Bacillus thuringiensis israelensis.

Aedes↗
PubMed1994

[The use of PCR for detecting pathogenic microorganisms in water].

This replication method, which was introduced in 1985, has been used to find and identify microorganisms in the environment, among others in samples of soil, sediments and waters. A gene or a DNA fragment specific to a microorganism is replicated in vitro by a chain reaction catalyzed by DNA polymerase (PCR: Polymerase Chain Reaction) and analyzed by electrophoretic procedures. At the moment in most legislations bacteriological criteria for drinking water depend on E. coli and other bacteria referring to fecal contamination (fecal coliforms and enterococci). Absence of these bacteria does not necessarily exclude contamination of water with protozoa or virus. Detection of the latter by common methods is difficult and time-consuming. Application of PCR to these purposes is interesting. During the last years several protocols have been developed such as methods for the detection of E. coli, bacteria referring to fecal contamination, pathogens like Legionella pneumophila as well as Salmonella and Shigella, enterovirus and protozoa i.e. Giardia. Compared to the traditional methods an obvious advantage of the new methods lies in their velocity, sensitivity and specificity. This review introduces to several different applications of PCR. Although this method is still restricted to specialized laboratories at the moment, it will gain importance as a complement to traditional methods for the detection of pathogenic microorganisms in water as soon as simple tests will be available.

Animals↗
PubMed1996

Strategies to Prevent and Control the Emergence and Spread of Antimicrobial-Resistant Microorganisms in Hospitals. A challenge to hospital leadership.

OBJECTIVE: To provide hospital leaders with strategic goals or actions likely to have a significant impact on antimicrobial resistance, outline outcome and process measures for evaluating progress toward each goal, describe potential barriers to success, and suggest countermeasures and novel improvement strategies. PARTICIPANTS: A multidisciplinary group of experts was drawn from the following areas: hospital epidemiology and infection control, infectious diseases (including graduate training programs), clinical practice (including nursing, surgery, internal medicine, and pediatrics), pharmacy, administration, quality improvement, appropriateness evaluation, behavior modification, practice guideline development, medical informatics, and outcomes research. Representatives from appropriate federal agencies, the Joint Commission on Accreditation of Healthcare Organizations, and the pharmaceutical industry also participated. EVIDENCE: Published literature, guidelines, expert opinion, and practical experience regarding efforts to improve antibiotic utilization and prevent and control the emergence and dissemination of antimicrobial-resistant microorganisms in hospitals. CONSENSUS PROCESS: Participants were divided into two quality improvement teams: one focusing on improving antimicrobial usage and the other on preventing and controlling transmission of resistant microorganisms. The teams modeled the process a hospital might use to develop and implement a strategic plan to combat antimicrobial resistance. CONCLUSIONS: Ten strategic goals and related process and outcome measures were agreed on. The five strategic goals to optimize antimicrobial use were as follows: optimizing antimicrobial prophylaxis for operative procedures; optimizing choice and duration of empiric therapy; improving antimicrobial prescribing by educational and administrative means; monitoring and providing feedback regarding antibiotic resistance; and defining and implementing health care delivery system guidelines for important types of antimicrobial use. The five strategic goals to detect, report, and prevent transmission of antimicrobial resistant organisms were as follows: to develop a system to recognize and report trends in antimicrobial resistance within the institution; develop a system to rapidly detect and report resistant microorganisms in individual patients and ensure a rapid response by caregivers; increase adherence to basic infection control policies and procedures; incorporate the detection, prevention, and control of antimicrobial resistance into institutional strategic goals and provide the required resources; and develop a plan for identifying, transferring, discharging, and readmitting patients colonized with specific antimicrobial-resistant pathogens.

Anti-Bacterial Agents↗
PubMedDate not supplied

Dairy product analysis: identification of microorganisms by mid-infrared spectroscopy and determination of constituents by Raman spectroscopy.

Identification of microorganisms by traditional microbiological methods is time consuming. The German Federal Health Office has developed a method using mid-infrared spectroscopy to identify microorganisms rapidly. This method has been modified for application to microorganisms important in the dairy industry. Mid- and near-infrared spectroscopies are well-established methods for quantitative measurements of fat, protein, lactose, and solid content in a variety of products. A disadvantage of both methods is the huge absorption due to water; extraction of other components is complicated and can be achieved only statistically. With Raman spectroscopy, water causes less absorption. We investigated the use of Raman spectroscopy as a quantitative method for milk powder.

Clostridium↗
PubMedDate not supplied

[The immune status of patients with acute inflammatory diseases of adnexa uteri associated with different combinations of microorganisms].

The immune status of 130 patients with acute inflammatory diseases of uterine appendages was studied. As etiologically associated infective agents detected in these patients were opportunistic microorganisms (group 1), Neisseria gonorrhoeae in combination with opportunistic microorganisms (group 2) and Chlamydia trachomatis in combination with opportunistic microorganisms (group 3). In all three groups of patients the response of T lymphocytes to PHA and hyperactivation of the B-cell element of immunity (an increase in the relative number of B-lymphocytes and the content of IgA and IgM in the serum) was found to be suppressed. In addition, in groups 1 and 3 an increase, and in group 2 a decrease in IgG were detected. In the mucus of the cervical canal in the patients of groups 1, 2 and 3 IgM was detected, while in patients of groups 2 and 3 a decrease in sigA was established.

Acute Disease↗
PubMed1996

Prevalence of microorganisms in dead mink kits from Aleutian-disease-infected and non-infected farms.

Bacterial and fungi were isolated from different tissues (brain, liver, heart) taken from 81 dead newborn mink originating from Aleutian disease (AD) infected and AD-non-infected farms. Of the 123 isolates obtained, 96% were bacterial isolates (predominantly Gram-negative) and 4% were fungi. The prevalence of microorganisms appeared less common in kits from AD-non-infected farms (55%) than from AD-infected farms (73%), although the difference was not significant. The liver was the most highly infected site in both groups and generally was only infected by one microorganism species. Proteus spp (23%), Escherichia coli (16%), Staphylococcus aureus (11%) and Enterobacter cloacae (9%) were the most frequently isolated germs. These findings are similar to those of other studies but the role of these microorganisms as specific pathogens or secondary invaders remains controversial.

Aleutian Mink Disease↗
PubMedDate not supplied

[An analysis of the physiological activity of organic compounds of ozokerite obtained by its biotransformation by naftusia water microorganisms].

A possibility to obtain physiologically active substances by means of biotransformation of natural carbohydrate raw material-ozokerite using the saprophite groups of microorganisms isolated from the medicinal water naftusia has been studied. It is shown that microorganisms metabolise ozokerite with following formation of the whole spectrum of water-soluble substances, activators and inhibitors of Na, K-ATPase, cholopoiesis stimulators being found among them. A conclusion has been made that using microorganisms inhabiting water naftusia can obtain from ozokerite organic substances conditioning physiologic activity of this medicinal water.

Animals↗
PubMed1997

[Climatic condition and airborne microorganisms in wild cat housing].

The aim of the present study was to obtain information to improve the environmental conditions in enclosures for cats of prey. There was a large variation in indoor temperature, relative humidity, concentration of airborne ammonia and microorganisms during the year. The ascertained concentrations of airborne microorganisms distinguished between the different housing systems and ranged between 7177 and 15,835 KBE/m3. The concentration correlated negatively with the temperature outside of the buildings, while the amount of each compound, especially the gram positive cocci and rods, was influenced by the microclimate of the stables. The gram negative germs covered only 4.5 to 7.5%. Therefore the gram positive microorganisms were predominant. Part of the primary pathogen germs was low and amounted below 1%. There was now risks for visitors to get an infectious disease caused by the zoo animals.

Air Microbiology↗
PubMed1998

Investigations on the survival time of outdoor microorganisms on air filters.

Outdoor microorganism survival on air filters was examined in 16-day field investigations. Using a mobile filter testing device, samples of fiberglass pocket filters (filter class F7) were ventilated with outdoor air, and their microorganism contents were determined at 1, 2, 4, 8 and 16-day intervals. The results showed a mean survival time of microorganisms deposited on the air filters of 1 to 3 days.

Air Microbiology↗
PubMed1998

Microorganisms in closed periapical lesions.

The purpose of this study was to investigate the microorganisms of strictly selected closed periapical lesions associated with both refractory endodontic therapy and pulpal calcification. Definitive criteria were established that assured complete clinical isolation of the periapical lesion from the oral and periodontal environment. A total of 13 criteria-referenced lesions were selected from 70 patients with endodontic surgical indications. A well controlled culturing method was used in all cases and samples were taken by one clinician at three separate sites during each surgery. Samples taken at the surgical window and within the body of the lesion served as controls, whilst a third sample was taken at the apex. In all 13 cases, samples taken from the apex yielded microorganisms comprising 63.6% obligate anaerobes and 36.4% facultative anaerobes. Prevalence of the isolated species was 31.8% for Actinomyces sp., 22.7% Propionibacterium sp., 18.2% Streptococcus sp., 13.6% Staphlyococcus sp., 4.6% Porphyromonas gingivalis, 4.6% Peptostreptococcus micros and 4.6% Gram-negative enterics. The results of this investigation indicate that closed periapical lesions associated with calcified teeth or those resistant to root canal treatment harbour bacteria. The inability to eradicate all root canal microorganisms during root canal treatment, along with anatomical factors, may allow further bacterial colonization of the root apex and surrounding periapical tissues, and consequently prevent healing.

Bacteria, Anaerobic↗
PubMed1987

Surface biofilm disruption. Enhanced recovery of microorganisms from vascular prostheses.

Ultrasonic oscillation (sonication) of explanted vascular prosthetic graft material can disrupt surface biofilms and increase the recovery of adherent microorganisms. Recovery of microorganisms from vascular grafts was studied in a canine model of Staphylococcus epidermidis graft contamination (N = 26) and on graft material excised from patients undergoing femoral anastomotic pseudoaneurysm repair (N = 7). Surface biofilm disruption by sonication significantly increased the incidence of positive cultures of excised graft material compared with broth (P less than .010) and blood agar plate (P less than .005) culture techniques. The S epidermidis was recovered from 31% of the canine vascular grafts and 100% of the clinical specimens. The in vitro production of a glycocalyx "slime" was demonstrated in 73% of the recovered staphylococcal strains. The formation of an adherent bacteria biofilm on implanted vascular prostheses is not an uncommon occurrence and is an important factor in the pathogenesis of anastomotic pseudoaneurysm formation and late graft infection.

Animals↗
PubMed1997

Quantitative flow cytometric detection of specific microorganisms in soil samples using rRNA targeted fluorescent probes and ethidium bromide.

Specific detection and accurate enumeration of microorganisms in the environment have been hampered by the lack of suitable techniques. A three-parameter flow cytometric method (FCM) was developed to detect quantitatively Sphingomonas sp. strain 107 inoculated into soil samples. By combining light scattering profiles (i.e., morphological properties), ethidium bromide (EtBr) influx (i.e., wall permeability), and fluorescence in situ hybridization against the 16S rRNA (i.e., detection specificity), we could accurately discriminate the bacterium of interest from the indigenous microflora and soil debris. EtBr was used, first, to determine the optimal cell wall permeabilization treatment to allow oligonucleotide probes to enter the bacterial cells and, second, to achieve clear discrimination of fixed cells from debris in soil samples. This method allowed effective qualitative and quantitative analysis by fluorescence in situ hybridization. The results showed that the detection threshold by FCM was 3 x 10(4) cells/g of dry soil. Cell counts deduced from FCM analysis were similar to those obtained by the colony forming unit assay when soils contained fewer than 3 x 106 cells/g dry soil. This method should be useful for either quantitative monitoring of microorganisms inoculated in contaminated soil samples during bioremediation or detecting known bacterial strains in environmental samples.

Cell Separation↗
PubMed1999

Interactions between the bioactive glass S53P4 and the atrophic rhinitis-associated microorganism klebsiella ozaenae.

In an aqueous environment, ions are released from a bioactive glass (BAG) and the pH rises in its vicinity. This may influence both growth and colonization of microorganisms. We studied the effects of the BAG S53P4 on the atrophic rhinitis-associated microorganism Klebsiella ozaenae. The glass was used in the form of granules or discs. Growth inhibition was studied using an agar plate test. Adhesion was studied by incubating bacterial suspension with the glass. The effect of the presence of the bacteria on the formation of the Si-rich layer on the bioactive glass was also analyzed. Furthermore, a follow up study of 19-74 months with ozena patients surgically treated with the BAG S53P4 was performed. The bioactive glass showed no clear growth inhibition of K. ozaenae in the agar plate test. K. ozaenae showed low adherence to the BAG S53P4. No growth of the microbe was seen on the glass during the 8 h incubations and the Si-rich layer was formed normally. The clinical follow-up study showed no infections of the implants and the symptoms of the patients were markedly reduced. Thus, the BAG S53P4 did not favor adhesion and colonization of K. ozaenae, in vitro, which is supported by the in vivo findings showing no BAG-associated infections or reinfections.

Adolescent↗
PubMed2002

Monitoring the migration behavior of living microorganisms in capillary electrophoresis using laser-induced fluorescence detection with a charge-coupled device imaging system.

Remarkably high apparent peak efficiencies (10(6)-10(9) theoretical plates per meter) in capillary electrophoresis (CE) could be achieved in the separation of two different kinds of bacteria and Baker's yeast using poly(ethylene oxide) as a necessary buffer additive. In these applications no deliberate stacking procedure was implemented. Seemingly, the investigated organisms in this study behave differently than molecules under an applied electric field. For molecules, these extremely high efficiencies are very unusual. Using a 488 nm argon-ion laser coupled to a charge-coupled device (CCD) camera it was possible to monitor the migration behavior of stained microorganisms over a length of 10 cm. This part simulates the very beginning of the CE run. In specific cases 60-70% of the monitored detection window could be filled with analyte without significant loss in peak efficiency. For a mixture of two different microorganisms the occurring separation process could be followed in detail. The effect of buffer concentration, polymer type, polymer molecular weight, polymer concentration, pH, and the effect of injection time was investigated. The expansion of fast and reproducible CE separations to other unicellular organisms may become a powerful tool in microbiological science and technology.

Bifidobacterium↗
PubMed2005

Suicidal genetically engineered microorganisms for bioremediation: need and perspectives.

In the past few decades, increased awareness of environmental pollution has led to the exploitation of microbial metabolic potential in the construction of several genetically engineered microorganisms (GEMs) for bioremediation purposes. At the same time, environmental concerns and regulatory constraints have limited the in situ application of GEMs, the ultimate objective behind their development. In order to address the anticipated risks due to the uncontrolled survival/dispersal of GEMs or recombinant plasmids into the environment, some attempts have been made to construct systems that would contain the released organisms. This article discusses the designing of safer genetically engineered organisms for environmental release with specific emphasis on the use of bacterial plasmid addiction systems to limit their survival thus minimizing the anticipated risk. We also conceptualize a novel strategy to construct "Suicidal Genetically Engineered Microorganisms (SGEMs)" by exploring/combining the knowledge of different plasmid addiction systems (such as antisense RNA-regulated plasmid addiction, proteic plasmid addiction etc.) and inducible degradative operons of bacteria.

Bacteria↗
PubMed2003

Titrostat: a reliable technique for continuous cultivation of microorganisms utilizing liquid or gaseous water insoluble substrates.

We describe a method for continuous cultivation of microorganisms utilizing liquid or gaseous water insoluble substrates as a single source of carbon and energy. The water insoluble substrate, which is also the growth-limiting factor, enters the cultivation space as a manually adjustable single-compound material flow. All nonlimiting nutrients (with the exception of oxygen) enter the cultivation space as ingredients of titrant solution which feed rate is reliably coupled to the rate of substrate addition by means of the system titrator. The method provides mild starting conditions appropriate for primary isolation of microorganisms utilizing substrates with growth-inhibiting properties such as BTEX (benzene, toluene, ethylbenzene, and xylene). The sound control over the microbial specific growth rate makes it suitable for precise kinetic studies as well. We provide a detailed description of both the principles of the method and the equipment used. The dependence of the systems operative range on the concentration of titrant solution is illustrated in the case of continuous cultivation of a mixed bacterial culture on toluene.

Acinetobacter↗
PubMed2004

Williopsis californica, Williopsis saturnus, and Pachysolen tannophilus: novel microorganisms for stereoselective oxidation of secondary alcohols.

A screening of 416 microorganisms from different taxonomical groups (bacteria, actinomycetes, yeasts, and filamentous fungi) has been performed looking for active strains in the stereoselective oxidation of secondary alcohols. The working collection was composed of 71 bacterial strains, 45 actinomycetes, 59 yeasts, 60 basidiomycetes, 33 marine fungi, and 148 filamentous fungi. All microorganisms selected were mesophilic. Yeasts were the most active microbial group in the whole-cell-catalyzed oxidation. Williopsis californica, Williopsis saturnus, and Pachysolen tannophilus were the strains of greatest interest, both as growing cells and as resting cells. The oxidation of the alcohols takes place when cells are in the stationary growth phase (after 48 h of culture). These three strains are S-stereoselective for the oxidation of racemic secondary alkanols and show stereospecificity in the oxidation of menthol or neo-menthol, whereas iso-menthol is not oxidized. In the case of the 1-tetrahydronaphtol enantiomers, only the S-enantiomer is oxidized. The three strains were immobilized by entrapment using agarose and agar from algae of the Gracilaria genus. The agarose derivatives displayed significant improvement in the stereospecificity of the reactions.

Alcohols↗