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Biomedical subjects

C B Fliermans

Publications and source records attributed to C B Fliermans.

At least 19 recordsLinked to original sources
PubMed1998

Microbiology of spent nuclear fuel storage basins.

Microbiological studies of spent nuclear fuel storage basins at Savannah River Site (SRS) were performed as a preliminary step to elucidate the potential for microbial-influenced corrosion (MIC) in these facilities. Total direct counts and culturable counts performed during a 2-year period indicated microbial densities of 10(4) to 10(7) cells/ml in water samples and on submerged metal coupons collected from these basins. Bacterial communities present in the basin transformed between 15% and 89% of the compounds present in Biologtrade mark plates. Additionally, the presence of several biocorrosion-relevant microbial groups (i.e., sulfate-reducing bacteria and acid-producing bacteria) was detected with commercially available test kits. Scanning electron microscopy and X-ray spectra analysis of osmium tetroxide-stained coupons demonstrated the development of microbial biofilm communities on some metal coupons submerged for 3 weeks in storage basins. After 12 months, coupons were fully covered by biofilms, with some deterioration of the coupon surface evident at the microscopical level. These results suggest that, despite the oligotrophic and radiological environment of the SRS storage basins and the active water deionization treatments commonly applied to prevent electrochemical corrosion in these facilities, these conditions do not prevent microbial colonization and survival. Such microbial densities and wide diversity of carbon source utilization reflect the ability of the microbial populations to adapt to these environments. The presumptive presence of sulfate-reducing bacteria and acid-producing bacteria and the development of biofilms on submerged coupons indicated that an environment for MIC of metal components in the storage basins may occur. However, to date, there has been no indication or evidence of MIC in the basins. Basin chemistry control and corrosion surveillance programs instituted several years ago have substantially abated all corrosion mechanisms.

Bacteriological Techniques↗
PubMed1997

Ecofunctional enzymes of microbial communities in ground water.

Biolog technology was initially developed as a rapid, broad spectrum method for the biochemical identification of clinical microorganisms. Demand and creative application of this technology has resulted in the development of Biolog plates for Gram-negative and Gram-positive bacteria, for yeast and Lactobacillus sp. Microbial ecologists have extended the use of these plates from the identification of pure culture isolates to a tool for quantifying the metabolic patterns of mixed cultures, consortia and entire microbial communities. Patterns that develop on Biolog microplates are a result of the oxidation of the substrates by microorganisms in the inoculum and the subsequent reduction of the tetrazolium dye to form a color in response to detectable reactions. Depending upon the functional enzymes present in the isolate or community one of a possible 4 x 10(28) patterns can be expressed. The patterns were used to distinguish the physiological ecology of various microbial communities present in remediated groundwater. The data indicate that one can observe differences in the microbial community among treatments of bioventing, 1% and 4% methane injection, and pulse injection of air, methane and nutrients both between and among wells. The investigation indicates that Biolog technology is a useful parameter to measure the physiological response of the microbial community to perturbation and allows one to design enhancement techniques to further the degradation of selected recalcitrant and toxic chemicals. Further it allows one to evaluate the recovery of the microbial subsurface ecosystem after the perturbations have ceased. We propose the term 'ecofunctional enzymes' (EFE) as the most descriptive and useful term for the Biolog plate patterns generated by microbial communities. We offer this designation and provide ecological application in an attempt to standardize the terminology for this relatively new and unique technology.

Bacteria↗
PubMed1994

Reductive Dechlorination of Trichloroethylene and Tetrachloroethylene under Aerobic Conditions in a Sediment Column.

Biodegradation of trichloroethylene and tetrachloroethylene under aerobic conditions was studied in a sediment column. Cumulative mass balances indicated 87 and 90% removal for trichloroethylene and tetrachloroethylene, respectively. These studies suggest the potential for simultaneous aerobic and anaerobic biotransformation processes under bulk aerobic conditions.

Journal Article↗
PubMed1989

Effect of thermal additions on the density and distribution of thermophilic amoebae and pathogenic Naegleria fowleri in a newly created cooling lake.

Pathogenic Naegleria fowleri is the causative agent of fatal human amoebic meningoencephalitis. The protozoan is ubiquitous in nature, and its presence is enhanced by thermal additions. In this investigation, water and sediments from a newly created cooling lake were quantitatively analyzed for the presence of thermophilic amoebae, thermophilic Naegleria spp., and the pathogen Naegleria fowleri. During periods of thermal additions, the concentrations of thermophilic amoebae and thermophilic Naegleria spp. increased as much as 5 orders of magnitude, and the concentration of the pathogen N. fowleri increased as much as 2 orders of magnitude. Concentrations of amoebae returned to prior thermal perturbation levels within 30 to 60 days after cessation of thermal additions. Increases in the thermophilic amoeba concentrations were noted in Savannah River oxbows downriver from the Savannah River plant discharge streams as compared with oxbows upriver from the discharges. Concentrations of thermophilic amoebae and thermophilic Naegleria spp. correlated significantly with temperature and conductivity. Air samples taken proximal to the lake during periods of thermal addition showed no evidence of thermophilic Naegleria spp. Isoenzyme patterns of the N. fowleri isolated from the cooling lake were identical to patterns of N. fowleri isolated from other sites in the United States and Belgium.

Air↗
PubMed1988

Mineralization of trichloroethylene by heterotrophic enrichment cultures.

Microbial consortia capable of aerobically degrading more than 99% of exogenous trichloroethylene (TCE) (50 mg/liter) were collected from TCE-contaminated subsurface sediments and grown in enrichment cultures. TCE at concentrations greater than 300 mg/liter was not degraded, nor was TCE used by the consortia as a sole energy source. Energy sources which permitted growth included tryptone-yeast extract, methanol, methane, and propane. The optimum temperature range for growth and subsequent TCE consumption was 22 to 37 degrees C, and the pH optimum was 7.0 to 8.1. Utilization of TCE occurred only after apparent microbial growth had ceased. The major end products recovered were hydrochloric acid and carbon dioxide. Minor products included dichloroethylene, vinylidine chloride, and, possibly, chloroform.

Journal Article↗
PubMed1984

Effectiveness of 1-bromo-3-chloro-5,5-dimethylhydantoin against Legionella pneumophila in a cooling tower.

Cooling towers are considered to be man-made amplifiers of Legionella spp. Thus, the proper maintenance and choice of biocides is important. The only biocidal measure that has thus far been shown to be effective in field tests is the judicious use of chlorination. Perturbation studies with 1-bromo-3-chloro-5, 5-dimethylhydantoin (Bromicide; Great Lakes Chemical Corp., West Lafayette, Ind.) (BCD) were conducted on an industrial cooling tower shown to contain Legionella pneumophila. At the concentrations recommended by the manufacturer, neither the density nor the activity of L. pneumophila was affected. At comcentrations greater than 2.0 ppm (2.0 micorgram/ml) free of residual, BCD was not effective in reducing L. pneumophila to source water concentrations, nor was it effective in reducing the 2-p-iodophenyl-3-p-nitrophenyl-5-phenyl tetrazolium chloride activity of the bacterium in situ. The data indicate that at concentrations up to 2.0 ppm, BCD is not effective in these tower studies.

Hydantoins↗
PubMed1983

Legionella oakridgensis: unusual new species isolated from cooling tower water.

We describe a new species of Legionella represented by 10 strains isolated from industrial cooling towers. Legionella oakridgensis differed genetically from the other seven species of Legionella in DNA hybridization studies and differed serologically in direct fluorescent-antibody tests. The new species, unlike all other species except L. jordanis, did not require added L-cysteine for growth in serial transfer on charcoal-yeast extract agar. L. oakridgensis, as well as three other species tested, required L-cysteine for primary isolation from animal tissues. L. oakridgensis was the only species of Legionella that failed to produce alkaline phosphatase at pH 8.5. In all other respects, it resembled other species of Legionella, including having a high content of branched-chain cellular fatty acids and being pathogenic for guinea pigs. These bacteria have not yet been associated with human disease, but they are potential causes of legionellosis.

Air Conditioning↗
PubMed1983

Susceptibilities of algae and Legionella pneumophila to cooling tower biocides.

Nine algal strains and nine Legionella pneumophila strains were tested in laboratory culture for their susceptibility to inhibition by a variety of commercially available microbiocides. The responses ranged from ineffective to effective at 1/100 the manufacturers' recommended pulse doses. Tests were also performed to determine whether the action of the microbiocide was bacteriostatic or bacteriocidal.

Chlorophyta↗
PubMed1983

Autecology of Legionella pneumophila.

Species of Legionella are readily isolated from freshwater aquatic habitats throughout the United States, which are diverse in their physical and chemical parameters. Temperature studies indicate that Legionella is not present in habitats with temperatures above 63 degrees C, and isolates have been obtained from frozen rivers. The presence of the organism in natural hot springs and man-made thermal habitats suggest that Legionella may have been present for a long period of time, but has only recently had man-made thermal habitats suitable to establish niches common to man.

Ecology↗
PubMed1982

Application of flow cytometry to studies of pathogenic free-living amoebae.

Species of small, free-living amoebae of the genera Naegleria and Acanthamoeba can cause fatal amoebic meningoencephalitis. Previous investigations have shown that pathogenic amoebae are associated with thermally altered water. Flow cytometric techniques for identifying species of pathogenic and nonpathogenic amoebae from such water have been developed, using immunofluorescence and fluorescein-bound concanavalin A. Flow cytometry is accomplished with a cytofluorograph, in which cells are dispersed in a suspended carrier liquid and passed in front of a focused argon ion laser beam. Cells are then distinguished by the degree of scattered light (size) or fluorescence. Flow cytometry techniques have proven efficient for environmental samples, as indicated by the identification of pathogenic Naegleria fowleri and nonpathogenic Naegleri gruberi and Acanthamoeba castellanii isolated from the Savannah River Plant in South Carolina. Cytofluorographic analysis of environmental samples has several advantages over the current methods of isolation and classification of free-living amoebae. With this system, it is possible to rapidly identify species and quantitate mixtures of pathogenic amoebae in environmental samples. Cytofluorographic analysis of amoebic isolates reduces the time presently required to screen environmental sites for pathogenic amoebae. The cytofluorograph permits detection and species identification of nonthermophilic Naegleria spp. and Acanthamoeba spp. that could not easily be isolated for species identification by conventional methods. Other advantages of flow cytometry over fluorescent microscopy include a high degree of statistical precision due to the large numbers measured, high immunofluorescent titers, and elimination of subjectivity and fluorescence fading.

Agglutination Tests↗
PubMed1981

Ecological distribution of Legionella pneumophila.

Bacteria were concentrated 500-fold from 20-liter water samples collected from 67 different lakes and rivers in the United States. The data suggest that Legionella pneumophila is part of the natural aquatic environment and that the bacterium is capable of surviving extreme ranges of environmental conditions. The data further demonstrate the effectiveness of the direct fluorescent-antibody technique for detecting L. pneumophila in natural aquatic systems. Smears of the concentrated samples were screened microscopically for serogroups of L. pneumophila by the direct fluorescent-antibody technique. Virtually all of the 793 samples were found to be positive by this method. The 318 samples containing the largest numbers of positive bacteria which were morphologically consistent with L. pneumophila were injected into guinea pigs for attempted isolations. Isolates were obtained from habitats with a wide range of physical, chemical, and biological parameters. Samples collected monthly from a thermally altered lake and injected into guinea pigs demonstrated a seasonality of infection, with the highest frequency of infection occurring during the summer months.

Animals↗
PubMed1981

Characteristics of environmental isolates of Legionella pneumophila.

Thirty-eight cultures of Legionella pneumophila isolated from surface waters were characterized by their morphological, tinctorial, biochemical, and serological properties and by their ability to produce disease in guinea pigs. Their susceptibility to antimicrobial agents also was tested. When they were compared with clinical isolates, no important differences were found between cultures from the two sources. Sodium hippurate hydrolysis, gelatin liquefaction, pigment formation, and beta-lactamase and alkaline phosphatase activity were useful in differentiating the four described species of Legionella. Hydrolysis of diacetylfluorescein and the inability to reduce nitrate help to distinguish Legionella species from other gram-negative bacterial rods.

Alkaline Phosphatase↗
PubMed1980

Growth of Legionella pneumophila in association with blue-green algae (cyanobacteria).

Legionella pneumophila (Legionnaires disease bacterium) of serogroup 1 was isolated from an algal-bacterial mat community growing at 45 degrees C in a man-made thermal effluent. This isolate was grown in mineral salts medium at 45 degrees C in association with the blue-green alga (cyanobacterium) Fischerella sp. over a pH range of 6.9 to 7.6. L. pneumophila was apparently using algal extracellular products as its carbon and energy sources. These observations indicate that the temperature, pH, and nutritional requirements of L. pneumophila are not as stringent as those previously observed when cultured on complex media. This association between L. pneumophila and certain blue-green algae suggests an explanation for the apparent widespread distribution of the bacterium in nature.

Bacteria↗
PubMed1980

Immunofluorescence of Aeromonas hydrophila as measured by fluorescence photometric microscopy.

Strain-specific fluorescent antibodies were prepared for three isolates of Aereomonas hydrophila. These antisera were reacted with 255 other A. hydrophila isolates, and their immunofluorescence was measured quantitatively by photometric fluorescence microscopy. Only 27.5% of the isolates reacted with the prepared antisera which indicated that other undetected serogroups are present. Statistical analyses indicated that the A. hydrophila isolated from aquatic habitats were distinct from the other isolates as measured by immunofluorescence.

Aeromonas↗
PubMed1979

Isolation of Legionella pneumophila from nonepidemic-related aquatic habitats.

Continuous centrifugation of large volumes of water from natural southeastern lakes allowed quantitative detection of Legionella pneumophila by direct immunofluorescent staining. Positive samples were injected intraperitoneally into guinea pigs, and the L. pneumophila were isolated and identified by their morphological, cultural, physiological, and serological characteristics.

Animals↗
PubMed1979

Distribution of Aeromonas hydrophila in natural and man-made thermal effluents.

Densities of Aeromonas hydrophila showed distinct thermal optima (25 to 35 degrees C) and thermal maxima (45 degrees C) when measured along thermal gradients created by geothermal and nuclear reactor effluents. Survival of A. hydrophila never exceeded 48 h at temperatures of greater than 45 degrees C. Thermophilic strains could not be isolated at any site.

Aeromonas↗
PubMed1979

Isolation of Aeromonas hydrophila from the American alligator, Alligator mississippiensis.

Aeromonas hydrophila was isolated from the internal organs of nine adult alligators, Alligator mississippiensis, which died without apparent cause, suggesting the bacterium may have been a factor. One hundred and twenty-three alligators ranging in age from six months to over 10 years were captured from five locations in the southeastern United States and sampled for A. hydrophila. The bacterium was isolated from the oral cavity of 85% of the animals, on the external jaw area from over 50% and from 70% of the internal tissue samples. A. hydrophila is ubiquitous with alligators in their natural habitats, but apparently does not cause clinical disease. However, stress factors such as trapping, handling, and warm water temperatures may be conducive to the rapid proliferation of the bacteria, thereby facilitating disease.

Aeromonas↗