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Biomedical subjects

J S Elborn

Publications and source records attributed to J S Elborn.

At least 55 records · Page 3Linked to original sources
PubMed2002

Incidence of Pseudomonas aeruginosa in recreational and hydrotherapy pools.

Pseudomonas aeruginosa remains an important agent of opportunistic infection in patients, particularly those with respiratory complications and burns. One natural niche of this organism is water and water-associated facilities, hence the aim of this study was to examine specimens from recreational and hydrotherapy pools in Northern Ireland over a two-year period. Water specimens (n = 3,510) were obtained from three amenity categories, namely, 13 hydrotherapy pools (specimen number [n] = 323), 51 Jacuzzis/spas (n = 1,397) and 68 swimming pools (n = 1,790). Specimens (100 ml) were filtered through a cellulose acetate (0.45 micron pore size) gridded filter and the membrane was placed on Pseudomonas CFC agar (Oxoid CM559 + SR103) and incubated at 37 degrees C for 48 +/- 2 h. Colonies that clearly showed pyocyanin production or met other identification criteria were considered P. aeruginosa. Of the amenities examined 4/13 hydrotherapy pools (30.8%), 37/51 Jacuzzis/spas (72.5%) and 26/68 swimming pools (38.2%) were positive for P. aeruginosa. The most heavily contaminated amenity category was the Jacuzzi/spa, where 34.7% and 12% of private and public sites respectively were positive for P. aeruginosa at a level of greater than 1,000 cfu 100 ml-1. Approximately twice as many samples were positive in private Jacuzzis/spas compared to publicly operated facilities. There was a similar trend with respect to public and private hydrotherapy pools, though bacterial counts did not exceed 1,000 cfu 100 ml-1. Recreational and therapeutic amenities involving the use of water may be a potential source of P. aeruginosa for susceptible patient groups, including patients with cystic fibrosis and bronchiectasis. This may vary depending on amenity type and public/private ownership of such amenities.

Humans↗
PubMed2001

Long-term preservation of strains of Burkholderia cepacia, Pseudomonas spp. and Stenotrophomonas maltophilia isolated from patients with cystic fibrosis.

Long-term preservation methods are important in the maintenance of bacteria for downstream research applications. Most clinical laboratories have only limited resources for archiving isolates and therefore require cost-effective and simple methods. An effective and cheap storage method using debrinated blood and maintenance at -80 degrees C is described.

Bacteriological Techniques↗
PubMed2001

Rapid characterization of the genomovars of the Burkholderia cepacia complex by PCR-single-stranded conformational polymorphism (PCR-SSCP) analysis.

Four polymerase chain reaction (PCR) primer pairs (A-D), specific for the Burkholderia cepacia complex of organisms were designed to encompass the entire gene (approximately 1300 bp) from sequence alignments of the rec A operon of B. cepacia. Genomic bacterial DNA from type strains and wild-type B. cepacia complex isolates of previously determined genomovar status was amplified employing these four primer pairs, as well as a fifth primer set (E) already published. Primer sets B, C and E were successful in obtaining a PCR amplicon of correct estimated size of 598, 1107 and 1043 bp, respectively. Subsequent single-stranded conformational polymorphism (SSCP) analysis of PCR amplicons demonstrated unique profiles for the five genomovar types for primer pairs B and E, but was unable to differentiate distinguishable profile types for primer pair C. SSCP analysis was demonstrated to be simple, rapid and cost effective and may prove a useful method of genomovar typing of B. cepacia complex organisms from cystic fibrosis patients in busy diagnostic laboratories.

Burkholderia cepacia↗
PubMed2001

Total energy expenditure in stable patients with cystic fibrosis.

BACKGROUND AND AIMS: Undernutrition is a common problem in patients with cystic fibrosis and is associated with a poor prognosis. The two aims of this study were to assess and compare the two main field techniques in the measurement of total energy expenditure and, secondly, to assess total energy expenditure in stable patients and compare with healthy controls. METHODS: Resting energy expenditure was measured using indirect calorimetry and total energy expenditure was measured using 24-h heart rate (HR) methodology and doubly isotopically labelled water. RESULTS: Seventeen patients, mean age 23 years and FEV(1)52% predicted and thirteen controls were recruited. Resting energy expenditure was higher in patients 0.24 (0.03) MJ/kg Fat-Free Mass (FFM) compared to controls 0.22 (0.02) MJ/kg FFM, P=0.02. Twenty-four hour heart rate underestimated total energy expenditure, 9.49 (1.85) MJ/day in patients compared to 11.69 (2.79) MJ/day using doubly labelled water. There was no difference in total energy expenditure in patients and controls using both methods, 11.69 (2.79) MJ/day compared to 11.38 (2.71) MJ/day using doubly isotopically labelled water. CONCLUSIONS: In clinically stable young adult patients with moderately severe respiratory disease total energy expenditure is comparable to that an a control population despite in increase in resting energy expenditure and both 24-h HR and doubly isotopically labelled water are suitable for use in patients with cystic fibrosis.

Adult↗
PubMed2001

PCR-based detection and identification of Burkholderia cepacia complex pathogens in sputum from cystic fibrosis patients.

PCR amplification of the recA gene followed by restriction fragment length polymorphism (RFLP) analysis was investigated for the rapid detection and identification of Burkholderia cepacia complex genomovars directly from sputum. Successful amplification of the B. cepacia complex recA gene from cystic fibrosis (CF) patient sputum samples containing B. cepacia genomovar I, Burkholderia multivorans, B. cepacia genomovar III, Burkholderia stabilis, and Burkholderia vietnamiensis was demonstrated. In addition, the genomovar identifications determined directly from sputum were the same as those obtained after selective culturing. Sensitivity experiments revealed that recA-based PCR could reliably detect B. cepacia complex organisms to concentrations of 10(6) CFU g of sputum(-1). To fully assess the diagnostic value of the method, sputum samples from 100 CF patients were screened for B. cepacia complex infection by selective culturing and recA-based PCR. Selective culturing identified 19 samples with presumptive B. cepacia complex infection, which was corroborated by phenotypic analyses. Of the culture-positive sputum samples, 17 were also detected directly by recA-based PCR, while 2 samples were negative. The isolates cultured from both recA-negative sputum samples were subsequently identified as Burkholderia gladioli. RFLP analysis of the recA amplicons revealed 2 patients (12%) infected with B. multivorans, 11 patients (65%) infected with B. cepacia genomovar III-A, and 4 patients (23%) infected with B. cepacia genomovar III-B. These results demonstrate the potential of recA-based PCR-RFLP analysis for the rapid detection and identification of B. cepacia complex genomovars directly from sputum. Where the sensitivity of the assay proves a limitation, sputum samples can be analyzed by selective culturing followed by recA-based analysis of the isolate.

Adolescent↗
PubMed2001

Improved cultural detection of Burkholderia cepacia from sputum in patients with cystic fibrosis.

AIMS: To evaluate the sensitivity and specificity of two selective media for the isolation of Burkholderia cepacia from sputum specimens in patients with cystic fibrosis (CF). METHODS: In total, 149 expectorated sputum specimens from 113 patients with CF (32 cepacia colonised patients and 81 non-cepacia colonised patients) attending three CF centres were examined for the presence of B cepacia on two selective media: (1) MAST selective agar, a commercially available selective medium widely used in the UK and (2) BCSA (B cepacia selective agar), a new medium recently described, which is used predominantly in North America. RESULTS: Burkholderia cepacia was isolated from 53 of 149 (35.6%) specimens examined, representing 32 of 113 (28.3%) patients, using both the MAST and BCSA media. Growth was most rapid on BCSA with all (53 of 53) isolates detectable after 48 hours, compared with 50 of the 53 isolates on MAST agar, with the remaining three isolates detectable at five days. Twenty eight contaminants were identified on MAST agar and 13 on BCSA agar; mainly Alcaligenes xylosoxidans and yeast on MAST agar and Flavobacterium indologenes on BCSA medium. BCSA was equivalent to MAST agar in its ability to isolate B cepacia from patients with CF with a history of B cepacia infection. CONCLUSIONS: The increased selectivity and reduced time to detection of BCSA makes it an attractive alternative to MAST. However, its present limited commercial availability in the UK may delay its use in routine diagnostic laboratories because of complications with media preparation and quality control.

Adult↗
PubMed2001

Occurrence of Burkholderia cepacia in foods and waters: clinical implications for patients with cystic fibrosis.

Two hundred forty-eight retail "ready-to-eat" foodstuffs in eight food categories and 134 waters categorized into nine types were analyzed for the presence of the Burkholderia cepacia complex of organisms. Of these, 14 of 26 (53.8%) samples of raw unpasteurized bovine milk were positive for this organism. Consumption of raw unpasteurized milk may therefore act as a potential source of infection with this organism, which is of particular concern for patients with cystic fibrosis, where colonization and infection with this organism can lead to a fatal necrotizing pneumonia and premature death. In addition to the associated risk of infection from fecal pathogens, patients with cystic fibrosis should therefore avoid the consumption of raw unpasteurized milk to minimize the risk of becoming infected with this organism.

Animals↗
PubMed2001

Burkholderia cepacia and cystic fibrosis--50 years on.

Burkholderia cepacia (also known as Pseudomonas cepacia or P. multivorans), is a complex of bacteria that are phylogenetically distinguishable from each other but phenotypically indistinguishable. Though already present in the environment, they have been given selective advantage by changing environments and now infect a new and susceptible host group--cystic fibrosis sufferers. This brief review highlights the transmission of B. cepacia through the cystic fibrosis patient population and looks at possible treatments and current patient management approaches.

Burkholderia Infections↗
PubMed2000

Nitric oxide, iNOS, and inflammation in cystic fibrosis.

Nitric oxide (NO) is produced from three isoforms of nitric oxide synthase (NOS), neuronal (nNOS), endothelial (eNOS) and inducible (iNOS). Cystic fibrosis (CF) patients have an increased bacterial load in the airways which stimulates iNOS and therefore NO production. Upregulation of iNOS in normal epithelial cells protects the lung from damage, but in CF cells, iNOS is not upregulated and NO production is reduced. Reduced iNOS expression is associated with neutrophil sequestration in the lung, thus increasing the potential damage from neutrophil proteases and reactive oxygen species. In contrast, high concentrations of NO may augment the inflammatory process in acute lung injury from sepsis. Meng et al. have shown that cystic fibrosis epithelial cells, when stimulated by a cytokine mix and co-cultured with activated neutrophils, have reduced iNOS expression compared to normal epithelial cells. Although iNOS expression may not accurately reflect activity and NO production may arise from elsewhere, this study suggests that reduced iNOS expression may play a part in the pathophysiological processes in cystic fibrosis.

Cystic Fibrosis↗
PubMed2000

Pulmonary function, serum markers of inflammation, and IgG antibodies to core lipopolysaccharide of Burkholderia cepacia in adults with cystic fibrosis, following colonization with Burkholderia cepacia.

Eight patients with cystic fibrosis [CF] colonized with Pseudomonas aeruginosa (P. aeruginosa) had serial lung function, peripheral blood inflammatory markers, and serum IgG antibodies to Burkholderia cepacia (B. cepacia) lipopolysaccharide measured in the months preceding and following colonisation with B. cepacia. One patient experienced a fall in FEV(1) from 33% to 19% of predicted values, coinciding with the first sputum isolation of B. cepacia, and he died 12 weeks later. He had a rise in inflammatory markers preterminally, and this change was refractory to antibiotic therapy. There was no significant fall in FEV(1) % of predicted values in the remaining seven patients, and no significant changes in their serum markers of inflammation following colonization with B. cepacia over a median (range) period of 10.9 (7.3-12.0) months.

Adult↗
PubMed2000

Metabolic and inflammatory responses to pulmonary exacerbation in adults with cystic fibrosis.

BACKGROUND: We hypothesized that increased resting energy expenditure in adults with cystic fibrosis was related to chronic inflammation secondary to pulmonary infection and could be modified by treatment of the underlying infection. METHOD: To determine the relationship between resting energy expenditure and the inflammatory and metabolic responses, we studied 22 adults with cystic fibrosis and chronic Pseudomonas aeruginosa infection before and after treatment of a respiratory exacerbation. Resting energy expenditure was measured by indirect calorimetry. Spirometry and circulating concentrations of C-reactive protein, neutrophil elastase alpha1-antiproteinase complex, catecholamines, non-esterified fatty acids and glycerol were determined. RESULTS: The mean (95% confidence interval)% predicted FEV1 was 28.5% (20.6, 36.4) and mean body weight 50.7 kg (47.4, 54.1). Following treatment, 1-s forced expiratory volume (FEV1) and weight increased, while C-reactive protein (P<0.0001) and neutrophil elastase alpha1-antiproteinase complex concentrations (P<0.0001) were reduced. Resting energy expenditure decreased from 6.8 (6.3, 7.2) to 6.25 (5.9, 6.6) MJ day-1 by day 15 (P<0.001). Changes in resting energy expenditure and C-reactive protein were related (r = 0.66, P< 0.0001). Weight gain was inversely related to resting energy expenditure (r = 0.43, P = 0.02) and unrelated to energy intake (r = 0.02, P = 0.47). Post-treatment reduction in norepinephrine was related to changes in heart rate (r = 0.57, P<0.01), resting energy expenditure (r = 0.51, P = 0.001) and non-esterified fatty acids (r = 0.42, P< 0.05). CONCLUSIONS: A parallel reduction in the host inflammatory and catabolic responses followed treatment of a respiratory exacerbation and may have contributed to weight gain.

Adult↗
PubMed2000

Antibody response to Burkholderia cepacia in patients with cystic fibrosis colonized with Burkholderia cepacia and Pseudomonas aeruginosa.

INTRODUCTION: This study was designed to determine the relationship between formation of serum antibodies to lipopolysaccharide (LPS) core antigen of Burkholderia cepacia and pulmonary colonization with B. cepacia and Pseudomonas aeruginosa in patients with cystic fibrosis (CF), and to define if an enhanced host humoral immune response to B. cepacia was related to a poor clinical outcome. METHODS: Serum IgG to B. cepacia LPS core antigen was measured in adult cystic fibrosis patients colonized with B. cepacia and P. aeruginosa, and serial titres were measured in 13 B. cepacia and 41 P. aeruginosa colonized patients followed prospectively over 18 months. RESULTS: The median B. cepacia antibody titre was significantly greater in the patients colonized with B. cepacia compared to those colonized with P. aeruginosa, a group which grew B. cepacia intermittently from their sputum. and nine healthy controls. The median antibody titre at recruitment into the study was significantly greater in patients who later went into exacerbations compared with those who remained clinically stable. but there was no difference between B. cepacia antibody titres in patients who died and those who survived the study duration. DISCUSSION: The degree of overlap of serum IgG levels to B. cepacia LPS core antigen in cystic fibrosis patients colonized with B. cepacia and P. aeruginosa does not allow this antibody to be used in a clinical context to define infection status. The magnitude of the humoral response to B. cepacia may influence occurrence of pulmonary exacerbations, but a more exuberant humoral immune response to B. cepacia core LPS is not the mechanism by which pulmonary deterioration occurs.

Adolescent↗
PubMed2000

Cystic fibrosis: basic science.

Advances in the elucidation of cystic fibrosis transmembrane regulator (CFTR) function have resulted in a greater understanding of the relationship between the CF gene defect and clinical disease. The clinical phenotype is influenced by the class of mutation and possibly by other modifier genes. CFTR regulates the volume and composition of airways surface liquid, primarily by controlling chloride ion transport. However, CFTR also regulates other membrane channels and transports other molecules which may be important in mucocilary clearance and innate defence mechanisms. CFTR may also modulate the inflammatory response in respiratory epithelial cells and other inflammatory cells through a range of mechanisms. It is apparent that CFTR dysfunction results in a range of effects which may contribute to the clinical phenotype. These may contribute to the development of clinical disease at different stages of the natural history of cystic fibrosis. A greater understanding of the basic defect and its implications is likely to result in novel therapeutic approaches.

Bacterial Infections↗
PubMed2000

Elective versus symptomatic antibiotic treatment in cystic fibrosis patients with chronic Pseudomonas infection of the lungs.

BACKGROUND: A previous retrospective study suggested that a policy of regular anti-pseudomonal antibiotic treatment improved pulmonary function and increased survival in patients with cystic fibrosis chronically infected with Pseudomonas species. The results of a prospective multicentre study to compare the effects on pulmonary function and mortality of three monthly elective anti-pseudomonal antibiotic treatment with conventional symptomatic treatment are reported. METHODS: Sixty patients with cystic fibrosis, chronically infected with P aeruginosa, were randomised to the two treatment arms (elective or symptomatic) and followed clinically at yearly reviews. The major end points were changes in forced expiratory volume in one second (FEV(1)) and forced vital capacity (FVC). Survival was a secondary end point. RESULTS: Patients in the symptomatic group received a mean of three antibiotic treatments each year and those in the elective group received four antibiotic treatments during each year of the study. No significant differences in FEV(1) and FVC were found between the two groups after three years. There was a statistically non-significant higher rate of deaths in the elective group (n = 4), three of which were associated with B cepacia infection, compared with the symptomatic group (n = 0). CONCLUSIONS: This study did not demonstrate an advantage of a policy of elective antibiotic treatment over symptomatic treatment in patients with cystic fibrosis chronically infected with Pseudomonas species.

Adolescent↗