Die wedersydse belewenis van die interaksie tussen die persoon na aan die ernstig siek pasiënt en die verpleegkundige

M.Cur.The aim of the intensive care nurse is to give quality nursing to the critically ill surgical patient within the context of the family, as set out in her scope of practice. Various factors, however, affect the intensive care nurse's actions so that she does not achieve the aim. The persons close to the critically ill patient and the intensive care nurse form part of the patient's social external environment. Both of them are therefore important when facilitating health in the critically ill patient. The aim of this study is to explore and describe the experience of mutual interaction between the person close to the critically ill patient and the intensive care nurse and subsequently to create guidelines with regard to the intensive care nurse's handling of the person close to the critically ill patient during the patient's stay in an intensive care unit. The study is done by means of an exploratory, descriptive and contextual design by using the phenomenological method of interviewing. The participants were selected by purposive sampling according to selection criteria and represent various cultures. Nine persons close to the critically ill patient and six intensive care nurses comprised the participating population

Anaerobic Oxidation of o-Xylene, m-Xylene, and Homologous Alkylbenzenes by New Types of Sulfate-Reducing Bacteria

Various alkylbenzenes were depleted during growth of an anaerobic, sulfate-reducing enrichment culture with crude oil as the only source of organic substrates. From this culture, two new types of mesophilic, rod-shaped sulfate-reducing bacteria, strains oXyS1 and mXyS1, were isolated with o-xylene and m-xylene, respectively, as organic substrates. Sequence analyses of 16S rRNA genes revealed that the isolates affiliated with known completely oxidizing sulfate-reducing bacteria of the δ subclass of the class Proteobacteria. Strain oXyS1 showed the highest similarities to Desulfobacterium cetonicum and Desulfosarcina variabilis (similarity values, 98.4 and 98.7%, respectively). Strain mXyS1 was less closely related to known species, the closest relative being Desulfococcus multivorans (similarity value, 86.9%). Complete mineralization of o-xylene and m-xylene was demonstrated in quantitative growth experiments. Strain oXyS1 was able to utilize toluene, o-ethyltoluene, benzoate, and o-methylbenzoate in addition to o-xylene. Strain mXyS1 oxidized toluene, m-ethyltoluene, m-isoproyltoluene, benzoate, and m-methylbenzoate in addition to m-xylene. Strain oXyS1 did not utilize m-alkyltoluenes, whereas strain mXyS1 did not utilize o-alkyltoluenes. Like the enrichment culture, both isolates grew anaerobically on crude oil with concomitant reduction of sulfate to sulfide

Molecular assessment of ammonia- and nitrite-oxidizing bacteria in full-scale activated sludge wastewater treatment plants

Nitrification was assessed in two full-scale wastewater treatment plants (WWTPs) over time using molecular methods. Both WWTPs employed a complete-mix suspended growth, aerobic activated sludge process (with biomass recycle) for combined carbon and nitrogen treatment. However, one facility treated primarily municipal wastewater while the other only industrial wastewater. Real time PCR assays were developed to determine copy numbers for total 16S rDNA (a measure of biomass content), the amoA gene (a measure of ammonia-oxidizers), and Nitrospira 16S rDNA gene (a measure of nitrite-oxidizers) in mixed liquor samples.Fil: Robinson, Kevin. University of Tennessee; Estados UnidosFil: Dionisi, Hebe Monica. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Centro Nacional Patagónico; ArgentinaFil: Harms, Gerda. University of Tennessee; Estados UnidosFil: Lsyton, Alice C.. University of Tennessee; Estados UnidosFil: Gregory, Igrid. University of Tennessee; Estados UnidosFil: Sayler, G. S.. University of Tennessee; Estados Unido

Quantification of Nitrosomonas oligotropha-Like Ammonia-Oxidizing Bacteria and Nitrospira spp. from Full-Scale Wastewater Treatment Plants by Competitive PCR

Utilizing the principle of competitive PCR, we developed two assays to enumerate Nitrosomonas oligotropha-like ammonia-oxidizing bacteria and nitrite-oxidizing bacteria belonging to the genus Nitrospira. The specificities of two primer sets, which were designed for two target regions, the amoA gene and Nitrospira 16S ribosomal DNA (rDNA), were verified by DNA sequencing. Both assays were optimized and applied to full-scale, activated sludge wastewater treatment plant (WWTP) samples. If it was assumed that there was an average of 3.6 copies of 16S rDNA per cell in the total population and two copies of the amoA gene per ammonia-oxidizing bacterial cell, the ammonia oxidizers examined represented 0.0033% ± 0.0022% of the total bacterial population in a municipal WWTP. N. oligotropha-like ammonia-oxidizing bacteria were not detected in an industrial WWTP. If it was assumed that there was one copy of the 16S rDNA gene per nitrite-oxidizing bacterial cell, Nitrospira spp. represented 0.39% ± 0.28% of the biosludge population in the municipal WWTP and 0.37% ± 0.23% of the population in the industrial WWTP. The number of Nitrospira sp. cells in the municipal WWTP was more than 62 times greater than the number of N. oligotropha-like cells, based on a competitive PCR analysis. The results of this study extended our knowledge of the comparative compositions of nitrifying bacterial populations in wastewater treatment systems. Importantly, they also demonstrated that we were able to quantify these populations, which ultimately will be required for accurate prediction of process performance and stability for cost-effective design and operation of WWTPs

Power Analysis for Real-Time PCR Quantification of Genes in Activated Sludge and Analysis of the Variability Introduced by DNA Extraction

The aims of this study were to determine the power of discrimination of the real-time PCR assay for monitoring fluctuations in microbial populations within activated sludge and to identify sample processing points where methodological changes are needed to minimize the variability in target quantification. DNA was extracted using a commercially available kit from mixed liquor samples taken from the aeration tank of four bench-scale activated-sludge reactors operating at 2-, 5-, 10-, and 20-day solid retention times, with mixed-liquor volatile suspended solid (MLVSS) values ranging from 260 to 2,610 mg/liter. Real-time PCR assays for bacterial and Nitrospira 16S rRNA genes were chosen because they represent, respectively, a highly abundant and a less-abundant bacterial target subject to clustering within the activated sludge matrix. The mean coefficient of variation in DNA yields (measured as microgram of DNA per milligram of MLVSS) in triplicate extractions of 12 different samples was 12.2%. Based on power analyses, the variability associated with DNA extraction had a small impact on the overall variability of the real-time PCR assay. Instead, a larger variability was associated with the PCR assay. The less-abundant target (Nitrospira 16S rRNA gene) had more variability than the highly abundant target (bacterial 16S rRNA gene), and samples from the lower-biomass reactors had more variability than samples from the higher-biomass reactors. Power analysis of real-time PCR assays indicated that three to five samples were necessary to detect a twofold increase in bacterial 16S rRNA genes, whereas three to five samples were required to detect a fivefold increase in Nitrospira 16S rRNA genes

Real-time PCR quantification of nitrifying bacteria in a municipal wastewater treatment plant

Real-time PCR assays using TaqMan or Molecular Beacon probes were developed and optimized for the quantification of total bacteria, the nitrite-oxidizing bacteria Nitrospira, and Nitrosomonas oligotropha-like ammonia oxidizing bacteria (AOB) in mixed liquor suspended solids (MLSS) from a municipal wastewater treatment plant (WWTP) using a single-sludge nitrification process. The targets for the real-time PCR assays were the 16S rRNA genes (16S rDNA) for bacteria and Nitrospira spp. and the amoA gene for N. oligotropha. A previously reported assay for AOB 16S rDNA was also tested for its application to activated sludge. The Nitrospira 16S rDNA, AOB 16S rDNA, and N. oligotropha-like amoA assays were log-linear over 6 orders of magnitude and the bacterial 16S rDNA real-time PCR assay was log-linear over 4 orders of magnitude with DNA standards. When these real-time PCR assays were applied to DNA extracted from MLSS, dilution of the DNA extracts was necessary to prevent PCR inhibition. The optimal DNA dilution range was broad for the bacterial 16S rDNA (1000-fold) and Nitrospira 16S rDNA assays (2500-fold) but narrow for the AOB 16S rDNA assay (10-fold) and N. oligotropha-like amoA real-time PCR assay (5-fold). In twelve MLSS samples collected over one year, mean cell per L values were 4.3 ± 2.0 × 1011 for bacteria, 3.7 ± 3.2 × 1010 for Nitrospira, 1.2 ± 0.9 × 1010 for all AOB, and 7.5 ± 6.0 × 109 for N. oligotropha-like AOB. The percent of the nitrifying population was 1.7% N. oligotropha-like AOB based on the N. oligotropha amoA assay, 2.9% total AOB based on the AOB 16S rDNA assay, and 8.6% nitrite-oxidizing bacteria based on the Nitrospira 16S rDNA assay. Ammonia-oxidizing bacteria in the wastewater treatment plant were estimated to oxidize 7.7 ± 6.8 fmol/hr/cell based on the AOB 16S rDNA assay and 12.4 ± 7.3 fmol/hr/cell based on the N. oligotropha amoA assay.Fil: Harms, Gerda. University of Tennessee; Estados UnidosFil: Layton, Alice C.. University of Tennessee; Estados UnidosFil: Dionisi, Hebe Monica. University of Tennessee; Estados Unidos. Consejo Nacional de Investigaciones Científicas y Técnicas; ArgentinaFil: Gregory, Igrid R.. University of Tennessee; Estados UnidosFil: Garrett, Victoria M.. University of Tennessee; Estados UnidosFil: Hawkins, Shawn A.. University of Tennessee; Estados UnidosFil: Robinson, Kevin G.. University of Tennessee; Estados UnidosFil: Sayler, Gary S.. University of Tennessee; Estados Unido