A comparison of pulmonary exacerbations with single and multiple organisms in patients with cystic fibrosis and chronic Burkholderia cepacia infection

STUDY OBJECTIVES

To compare pulmonary exacerbations with single and multiple organisms in patients with chronic Burkholderia cepacia infection.

DESIGN

Data was collected over a 23-month period and for each of the patients two episodes of pulmonary exacerbation were identified, one with B. cepacia isolated as the sole respiratory pathogen and the other with one or more coinfecting organisms grown from the sputum culture.

SETTING

Regional tertiary referral center for Respiratory Medicine and Adult Cystic Fibrosis Center for Northern Ireland, Belfast City Hospital.

PATIENTS

Adult (over 16 years) CF patients with chronic (more than 4 years) B. cepacia complex infection who attended the Belfast City Hospital between January 1997 and November 1998.

MEASUREMENTS

Forced expiratory volume in 1s, forced vital capacity, forced expiratory flow rate 25-75, C-reactive protein, leucocyte count and body mass index were measured before and after two weeks of treatment and analysed for any differences in change between the two episodes.

RESULTS

All variables in both groups improved following treatment except for body mass index, which remained unchanged. No significant differences between the measurements were identified on comparison of single (monomicrobial) and multiple (polymicrobial) isolate episodes.

CONCLUSION

Patients with chronic B. cepacia infection who develop a pulmonary exacerbation improve, as reflected by clinical and biochemical markers, following IV antibiotic treatment. Pulmonary exacerbations with multiple organisms are no more severe than those where only B. cepacia is isolated.

Trends in the epidemiology of Candida bloodstream infections in Northern Ireland between January 1984 and December 2000

OBJECTIVE

To describe the epidemiology of Candida bloodstream infections (BSI) in Northern Ireland.

METHODS

Retrospective collation of data relating to all clinically significant BSI in a university teaching hospital, which had been recorded prospectively, between 1984 and 2000.

RESULTS

One hundred and forty five episodes of candidaemia occurred in 144 patients (of mean age 56.6 years). The contribution of Candida spp. towards all significant BSI increased from 2.0% to 2.5%. C. albicans was the most frequently isolated species, however, its incidence fell from 70% to 53% during the study period. The greatest increase in incidence was seen with C. glabrata which was the most common non-albicans species. Twenty-nine per cent of isolates occurred in patients from an intensive care unit and, surprisingly, a further 25.5% occurred in patients from a surgical service.

CONCLUSION

There appears to be several subtle differences in the epidemiology of candidal BSI between Northern Ireland and other countries.

Antibiotic resistant tuberculosis in the United Kingdom: 1993-1999

BACKGROUND

The re-emergence of tuberculosis as a global health problem over the past two decades, accompanied by an increase in tuberculosis drug resistance, prompted the development of a comprehensive national surveillance system for tuberculosis drug resistance in 1993.

METHODS

The UK Mycobacterial Resistance Network (Mycobnet), which includes all mycobacterial reference and regional laboratories in the UK, collects a minimum dataset on all individuals from whom an initial isolate of Mycobacterium tuberculosis complex has been isolated and submitted by source hospital laboratories. Data sought include susceptibility to first line antibiotics, demographic, geographical, and risk factor information.

RESULTS

There were 25 217 reports of initial isolates of M tuberculosis complex in the UK between 1993 and 1999. All were tested for sensitivity to isoniazid, rifampicin, and ethambutol and 12 692 of the isolates were also tested for sensitivity to pyrazinamide and streptomycin. A total of 1523 (6.1%) isolates were resistant to one or more drugs, 1397 isolates (5.6%) were resistant to isoniazid with or without resistance to other drugs, and 299 (1.2%) were multidrug resistant. Although the numbers of drug resistant isolates increased over the period, the proportions remained little changed. Certain groups of people were at a higher risk of acquiring drug resistant tuberculosis including younger men, residents of London, foreign born subjects, patients with a previous history of tuberculosis and those infected with HIV.

CONCLUSION

Although the proportion of drug resistant tuberculosis cases appears to be stable in the UK at present, more than one in 20 patients has drug resistant disease at diagnosis and more than one in 100 has multidrug resistant disease. Tuberculosis control measures should be strengthened to minimise the emergence of drug resistance through rapid diagnosis, rapid identification of drug resistance, supervised treatment, and maintenance of comprehensive surveillance.

Eradication of endotracheal tube biofilm by nebulised gentamicin

OBJECTIVE

To compare the efficacy of gentamicin, nebulised via the endotracheal tube (ET), with that of parenteral cefotaxime or parenteral cefuroxime in preventing the formation of ET biofilm.

SETTING

General intensive care units in two university teaching hospitals.

DESIGN

The microbiology of ET biofilm from 36 ICU patients eligible to receive antibiotic prophylaxis was examined. Peak and trough tracheal concentrations of gentamicin, cefotaxime or cefuroxime were measured in each patient group, on the 2nd day of intubation.

PATIENTS

Twelve patients received gentamicin (80 mg) nebulised in 4 ml normal saline every 8 h, 12 cefotaxime (1 g, 12 hourly) and 12 cefuroxime (750 mg, 8 hourly). Prophylaxis was continued for the duration of intubation.

MEASUREMENTS AND RESULTS

Samples of tracheal secretions were taken on the 2nd day of ventilation for determination of antibiotic concentrations. Following extubation, ETs were examined for the presence of biofilm. Pathogens considered to be common aetiological agents for VAP included Staphylococcus aureus, enterococci, Enterobacteriaceae and pseudomonads. While microbial biofilm was found on all ETs from the cephalosporin group, microbial biofilm of these micro-organisms was found on 7 of the 12 ET tubes from patients receiving cefotaxime [ S. aureus (4), pseudomonads (1), Enterobacteriaceae (1), enterococcus (1)] and 8 of the 12 ET tubes from patients receiving cefuroxime [Enterobacteriaceae (6), P. aeruginosa (1) and enterococcus (1)]. While microbial biofilm was observed on five ETs from patients receiving nebulised gentamicin, none of these were from pathogens for ventilator-associated pneumonia (VAP). Tracheal concentrations of both cephalosporins were lower than those needed to inhibit the growth of pathogens recovered from ET tube biofilm. The median (and range) concentrations for cefotaxime were 0.90 (<0.23-1.31) mg/l and 0.28 (<0.23-0.58) mg/l for 2 h post-dose and trough samples, respectively. Two hours post-dose concentrations of cefuroxime (median and range) were 0.40 (0.34-0.83) mg/l, with trough concentrations of 0.35 (<0.22-0.47) mg/l. Tracheal concentrations (median and range) of gentamicin measured 1 h post-nebulisation were 790 (352-->1250) mg/l and then, before the next dose, were 436 (250-1000) mg/l.

CONCLUSION

Nebulised gentamicin attained high concentrations in the ET lumen and was more effective in preventing the formation of biofilm than either parenterally administered cephalosporin and therefore may be effective in preventing this complication of mechanical ventilation.

Misidentification of a genomovar of Burkholderia cepacia by recA restriction fragment length polymorphism

An 8 year old girl with cystic fibrosis presented with a pulmonary exacerbation from which Burkholderia cepacia was cultured. Subsequent polymerase chain reaction restriction fragment length polymorphism analysis of the recA gene suggested the presence of B cepacia Genomovar V (Burkholderia vietnamiensis); however, on subsequent sequence typing, this isolate was confirmed as B cepacia Genomovar IIIb. This report outlines the potential difficulties in the correct characterisation of the various genomovars within the B cepacia complex of organisms, which has particularly important implications for patient segregation and infection control.

Molecular diagnosis of infective endocarditis--a new Duke's criterion

The molecular approach of PCR amplification of specific gene targets and universal loci for bacteria (16S rRNA) and fungi (18S, 28S and 5.8S rRNA) and subsequent sequencing was used to identify the possible causal microbial agent(s) in blood culture (47 patients) and heart valve material (30 patients) from patients with suspected infective endocarditis (IE). Culture and molecular results were analysed with respect to the patients' clinical background and the Duke Criteria. The findings demonstrated that: (i) all patients who were definite or possible cases were positive by PCR, even patients whose blood culture and valve material were culture-negative; and (ii) all patients who were rejected as having IE were also negative by PCR, with the exception of 1 patient who had bacteraemia from another source and 5 patients whose blood culture material was believed to contain an environmental contaminant. Direct molecular identification of the aetiological agents responsible for IE from blood culture material may enable specific treatment to commence at an earlier stage of the disease and hence reduce the need for valve replacement. Such a molecular approach may aid in the diagnosis of IE and should therefore be included as an additional major criterion in the Duke's classification scheme.

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.

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.

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.

Eye colour and reaction time to visual stimuli in rugby league players

Subjects with dark eye colour are thought to perform better on reactive tasks in comparison to light-eyed subjects, whereas light-eyed subjects show enhanced performance over dark-eyed subjects on self-paced activities. This study examined reaction time using unrestricted and peripheral vision and success at the self-paced activity of goal kicking in 59 elite male Rugby League players. Subjects with dark eye colour did not react significantly faster than the light-eyed subjects when tested using unrestricted vision or peripheral vision. Examination of the self-paced activity of goal kicking showed that the percentage success rate was not significantly higher in the light-eyed group than the dark-eyed group. In conclusion, there was no significant difference in reaction time to a visual stimulus or success in goal kicking between dark- and light-eyed Rugby League players.

A rapid molecular assay for the detection of antibiotic resistance determinants in causal agents of infective endocarditis

AIMS

To develop and employ a PCR amplification system, directly from clinical specimens, for the rapid molecular detection of common antimicrobial resistance genes for streptococci, staphylococci and enterococci organisms causing infective endocarditis (IE).

METHODS AND RESULTS

Eleven antibiotic resistance genes were targeted by PCR along with four identification-related loci. Blood culture and heart valve material from staphylococcal endocarditis patients were directly examined for methicillin resistance. PCR conditions were optimized for the following antibiotic resistance loci: staphylococci (mecA, aacA-aphD), streptococci (PBP 1A, PBP 2B, gyrB, parE) and enterococci (vanA, vanB, vanC-1, vanC-2, aacA-aphD, aphA3). The presence of methicillin resistance was confirmed in one of the eight IE patients examined.

CONCLUSION

This study presents a PCR amplification system for the detection of antibiotic resistance genes. Detection of such genes may indicate susceptibility of the causal agents of IE to commonly prescribed antimicrobial agents.

SIGNIFICANCE AND IMPACT OF THE STUDY

Rapid detection of antibiotic resistant organisms may reduce the use of inappropriate antibiotic agents or enable the use of the most appropriate combinations of antibiotics, other than those that would normally be prescribed empirically for IE. Such a method may be particularly valuable in cases of culture-negative endocarditis. Detection of antibiotic resistance genes by molecular-based techniques, namely PCR, will allow more directed antibiotic therapy and may also provide opportunities for earlier identification of resistant organisms.

Meeting the needs of consumers in the community: a working partnership in mental health in New Zealand

AIM

The aim was to evaluate whether the services community mental health nurses provide are meeting the needs of consumers in the community.

RATIONALE

The role of the mental health nurse in the community is changing as a result of deinstitutionalization, the consumer movement and the market model of health care delivery. In this context it is important for mental health nurses to evaluate whether the service they are currently providing is meeting the needs of consumers.

DESIGN

This was a joint project between nurses and consumers. It was a service-specific descriptive research project utilizing qualitative methods of data collection and analysis that provides a model for working in partnership.

FINDINGS

The results of this research identify collaboration in planning care and sharing information as two areas of concern but generally the consumers were very satisfied with the care provided by community mental health nurses. The analysis of the data suggests that consumers value nursing care because nurses provide support in their own home; they help consumers develop strategies for coping with their illness and their life; they provide practical assistance when it is required; they are vigilant about any deterioration or improvement; and they are available and accessible.

CONCLUSION

The results of this study have demonstrated that nurses will remain critical to the success of community-based care because of their ability and willingness to be flexible to the demands of their own organization and the users of services.

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.

What happens to stroke patients after hospital discharge?

Of 231 stroke patients discharged from hospital, 34 patients (14.7%) had died when reviewed 6 months later. Of 195 survivors, 115 (58%) were independent and living in the community. The remaining 80 (42%) patients were dependent. The majority of dependent patients were in institutional care but 29 (36%) were residing in the community of whom a substantial number were not receiving physiotherapy, occupational therapy or day care. Patients who were dependent in nursing homes were less likely to have received physiotherapy (48% versus 70%) or occupational therapy (28% versus 60%) compared to disabled patients in hospital based extended nursing care. 45 patients (24%) had been re-admitted to hospital although only 48% of patients had been reviewed in hospital outpatients since discharge. 64% of patients were on anti-thrombotic treatment. This survey suggests that 6 months after hospital discharge, most stroke patients are still alive and living in the community. Many of the dependent survivors have ongoing unmet medical and rehabilitation needs.

Mendel-GFDb and Mendel-ESTS: databases of plant gene families and ESTs annotated with gene family numbers and gene family names

There is no control over the information provided with sequences when they are deposited in the sequence databases. Consequently mistakes can seed the incorrect annotation of other sequences. Grouping genes into families and applying controlled annotation overcomes the problems of incorrect annotation associated with individual sequences. Two databases (http://www.mendel.ac.uk) were created to apply controlled annotation to plant genes and plant ESTs: Mendel-GFDb is a database of plant protein (gene) families based on gapped-BLAST analysis of all sequences in the SWISS-PROT family of databases. Sequences are aligned (ClustalW) and identical and similar residues shaded. The families are visually curated to ensure that one or more criteria, for example overall relatedness and/or domain similarity relate all sequences within a family. Sequence families are assigned a 'Gene Family Number' and a unified description is developed which best describes the family and its members. If authority exists the gene family is assigned a 'Gene Family Name'. This information is placed in Mendel-GFDb. Mendel-ESTS is primarily a database of plant ESTs, which have been compared to Mendel-GFDb, completely sequenced genomes and domain databases. This approach associated ESTs with individual sequences and the controlled annotation of gene families and protein domains; the information being placed in Mendel-ESTS. The controlled annotation applied to genes and ESTs provides a basis from which a plant transcription database can be developed.

Celiac disease in older people

In recent years, there has been increasing recognition that the classical textbook presentation of celiac disease with a malabsorption syndrome and a flat jejunal mucosa is only part of a broad spectrum of clinical and histological features associated with gluten sensitivity. Diagnosis of this treatable condition is often delayed or missed because of a failure to appreciate that celiac disease can present at any age and that symptoms are often subtle and not clearly related to gastrointestinal disease. Nonspecific symptoms and nutritional deficiencies are especially common in older patients and may not always be investigated thoroughly. Use of serological screening tests has improved ease of detection of celiac disease in patients without classical symptoms.

Prevalence of risk factors for ischaemic stroke and their treatment among a cohort of stroke patients in Dublin

BACKGROUND

The majority of strokes are due to ischaemia. Risk factors include atrial fibrillation, hypertension and smoking. The incidence can be reduced by addressing these risk factors. This study examines the prevalence of risk factors and their treatment in a cohort of patients with ischaemic stroke registered on a Dublin stroke database.

METHODS

Patients admitted to any of three acute hospitals with a diagnosis of stroke during a one-year period in 1997/98 were registered on a database using the European Stroke Database format. Data relating to common risk factors were analysed.

RESULTS

There were 238 ischaemic stroke cases registered. The most frequent medical risk factors were: hypertension (45%), atrial fibrillation (27.3%), and previous disabling or non-disabling stroke (33.2%). There was an increasing trend with advancing age for atrial fibrillation (p < 0.001). Some 23% (54/233) were current smokers. A significantly higher proportion of patients with no medical risk factors were smokers or consumed excessive alcohol compared with those who had medical risk factors.

CONCLUSION

Medical risk factors for stroke were common among stroke patients and not optimally treated, particularly with regard to atrial fibrillation and previous stroke. Smoking was a major behavioural risk factor among younger patients and much health gain could be achieved in this group through primary prevention strategies.

Defining discordance in twin studies of risk and protective factors for late life disorders

In studies that employ matched pair analysis to identify environmental exposures important for a disorder, criteria for discordant pairs are seldom discussed. Yet several assumptions concerning the definition of discordancy may have considerable influence over what results are found. Problems are exacerbated when age of onset for a disorder is late in life. We propose a new set of criteria for defining discordant pairs in studies of dementia, taking into account duration of discordance and competing causes of mortality, and evaluate the consequences of choosing alternative definitions of discordancy.

Telling the truth about cancer: views of elderly patients and their relatives

The aim of this study was to compare the attitudes of elderly patients and their relatives towards telling the truth about cancer. 120 patients were asked if they would wish to be told about bad news, such as cancer, which might emerge during the admission. Matched relatives were asked if such information should be disclosed to the patient. Of the 120 patients, 99 (83%) wanted to be told the truth; 66 relatives (55%) relatives wanted their next of kin informed. There was agreement in 73 (61%) pairs. The kappa statistic was 0.16 (95% confidence interval -0.03 to 0.35), which indicates poor agreement. We conclude that most elderly people wish to be informed of a diagnosis of cancer. Patient preferences cannot be predicted by talking to relatives.