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Aim: To examine the effectiveness of delivery of nebulised colistin by the HaloLite nebuliser compared to the Pari LC Plus in patients with cystic fibrosis. Methods: Randomised crossover trial of […]

These evidence-based guidelines are an updated version of those published in 2006. They have been produced after a literature review of the treatment and prophylaxis of methicillin-resistant Staphylococcus aureus (MRSA). The guidelines aim to complement those recently published for the antibiotic treatment of common and emerging community-onset MRSA infections in the UK. The guidelines have reviewed and updated, where appropriate, previous recommendations, taking into account any changes in the UK epidemiology of MRSA, ongoing national surveillance data and the value of new antistaphylococcal agents licensed for use in UK practice. Emerging therapies that have not been licensed for UK use are not reviewed, but their future potential role has been mentioned where deemed appropriate. Recommendations are given for the treatment of common infections caused by MRSA, elimination of MRSA from carriage sites and prophylaxis of surgical site infection. [ABSTRACT FROM AUTHOR]

Glycopeptides have been recommended as therapy for endocarditis. MICs and MBCs of vancomycin and teicoplanin were compared for 100 isolates from patients with proven bacterial endocarditis. MICs were generally lower for teicoplanin and tolerance to both agents was common. Almost all isolates of enterococci were tolerant to both glycopeptides. Among the streptococci, 78% were tolerant to teicoplanin and 57% to vancomycin. Similar findings were demonstrated for staphylococci. Although isolates appear sensitive to glycopeptides, bactericidal activity cannot always be predicted. If a glycopeptide is indicated for treatment of endocarditis, combination therapy with a suitable aminoglycoside should be considered unless MBC testing can be performed. [ABSTRACT FROM PUBLISHER]

The postperfusion syndrome, haemolytic anaemia and thrombocytopenic purpura following open heart surgery have all been attributed to acute cytomegalovirus (CMV) infection,'-3 usually acquired from perioperative transfusions of whole blood. Increased susceptibility of bacterial infections has been described,4 but only in patients who have undergone cardiac transplantation and consequently received immunosuppressive therapy. Studies have shown that CMV can suppress cell-mediated immunity in vivo and in vitro5 and impairment of neutrophil migration has been demonstrated in CMV infected mice.6 We describe a patient with impaired polymorph function associated with an acute CMV infection following aortic valve replacement. [ABSTRACT FROM PUBLISHER]

Objectives: Bloodstream infection has a high mortality rate. It is not clear whether laboratory-based rapid identification of the organisms involved would improve outcome., Methods: The RAPIDO trial was an open parallel-group multicentre randomized controlled trial. We tested all positive blood cultures from hospitalized adults by conventional methods of microbial identification and those from patients randomized (1:1) to rapid diagnosis in addition to matrix-assisted desorption ionization-time of flight mass spectrometry (MALDI-TOF MS) performed directly on positive blood cultures. The only primary outcome was 28-day mortality. Clinical advice on patient management was provided to members of both groups by infection specialists., Results: First positive blood culture samples from 8628 patients were randomized, 4312 into rapid diagnosis and 4136 into conventional diagnosis. After prespecified postrandomization exclusions, 2740 in the rapid diagnosis arm and 2810 in the conventional arm were included in the mortality analysis. There was no significant difference in 28-day survival (81.5% 2233/2740 rapid vs. 82.3% 2313/2810 conventional; hazard ratio 1.05, 95% confidence interval 0.93-1.19, p 0.42). Microbial identification was quicker in the rapid diagnosis group (median (interquartile range) 38.5 (26.7-50.3) hours after blood sampling vs. 50.3 (47.1-72.9) hours after blood sampling, p < 0.01), but times to effective antimicrobial therapy were no shorter (respectively median (interquartile range) 24 (2-78) hours vs. 13 (2-69) hours). There were no significant differences in 7-day mortality or total antibiotic consumption; times to resolution of fever, discharge from hospital or de-escalation of broad-spectrum therapy or 28-day Clostridioides difficile incidence., Conclusions: Rapid identification of bloodstream pathogens by MALDI-TOF MS in this trial did not reduce patient mortality despite delivering laboratory data to clinicians sooner., (Copyright © 2020 European Society of Clinical Microbiology and Infectious Diseases. Published by Elsevier Ltd. All rights reserved.)

Current guidelines for management of infective endocarditis (IE) advise 4-6 weeks of IV antibiotics. This is based on historical data from animal models, which set a precedent for high peak serum antimicrobial levels, thought to be only achievable with IV therapy. However, there has been increasing recent interest in oral antibiotics as an alternative to prolonged parenteral therapy, not limited to treatment of IE. This review examines the theory behind parenteral antibiotic administration with reference to the MICs of relevant pathogens. By comparing published serum antimicrobial levels after oral and IV administration we suggest that safe levels of commonly used antibiotics can be achieved orally. We have then reviewed the literature to date on oral antibiotics for IE. The largest randomized controlled trial (RCT) in this area, the POET trial, concluded that oral therapy was non-inferior to prolonged IV therapy in stable patients with left-sided IE. Additionally, there have been two smaller RCTs published, as well as a number of observational studies over the last 50 years, utilizing a variety of different patient groups, methods and treatment strategies. This body of evidence gives weight to a potential shift in practice towards oral therapy, primarily as a step-down treatment. We conclude that pharmacological data offer theoretical reassurance for the safety of oral therapy. This is coupled with a growing evidence base for non-inferiority of oral antimicrobials compared with prolonged parenteral therapy in practice., (© The Author(s) 2020. Published by Oxford University Press on behalf of the British Society for Antimicrobial Chemotherapy. All rights reserved. For permissions, please email: journals.permissions@oup.com.)

Background: Bloodstream infection is common in the UK and has significant mortality depending on the pathogen involved, site of infection and other patient factors. Healthcare staffing and ward activity may also impact on outcomes in a range of conditions, however there is little specific National Health Service (NHS) data on the impact for patients with bloodstream infection. Bloodstream Infections - Focus on Outcomes is a multicentre cohort study with the primary aim of identifying modifiable risk factors for 28-day mortality in patients with bloodstream infection due to one of six key pathogens., Methods: Adults under the care of five NHS Trusts in England and Wales between November 2010 and May 2012 were included. Multivariable Cox regression was used to quantify the association between modifiable risk factors, including staffing levels and timing of appropriate therapy, and 28-day mortality, after adjusting for non-modifiable risk factors such as patient demographics and long-term comorbidities., Results: A total of 1676 patients were included in the analysis population. Overall, 348/1676 (20.8%) died within 28 days. Modifiable factors associated with 28-day mortality were ward speciality, ward activity (admissions and discharges), movement within ward speciality, movement from critical care, and time to receipt of appropriate antimicrobial therapy in the first 7 days. For each additional admission or discharge per 10 beds, the hazard increased by 4% (95% CI 1 to 6%) in medical wards and 11% (95% CI 4 to 19%) in critical care. Patients who had moved wards within speciality or who had moved out of a critical care ward had a reduction in hazard of mortality. In the first 7 days, hazard of death increased with increasing time to receipt of appropriate antimicrobial therapy., Conclusion: This study underlines the importance of appropriate antimicrobials within the first 7 days, and the potential for ward activity and ward movements to impact on survival in bloodstream infection.

Objectives: Pseudomonas aeruginosa is an important pathogen in chronic suppurative respiratory diseases, with adverse effects on severity, healthcare utilization and quality of life. Aerosolized combined biofilm disruption and iron chelators offer novel proof-of-concept for improving airway antimicrobial efficacy. Our aim was to assess the activity of desferrioxamine, Dornase alfa (DNase) and antibiotics on biofilm formation and against mature preformed biofilms of P. aeruginosa., Methods: Fifty-six isolates of P. aeruginosa were screened for biofilm production and seven isolates with varying capacity to form biofilms were referred for further study. Three antibiotics (colistin, tobramycin and ciprofloxacin) as well as desferrioxamine and DNase were assessed for their ability to prevent biofilm formation using the crystal violet assay. The same method was used to assess their impact on mature biofilms. Each agent, as well as combinations of these agents, was also assessed for its effect on the metabolic activity and viability of preformed P. aeruginosa biofilm by the resazurin reduction assay and by performing viable counts., Results: Antibiotics alone prevented the development of biofilms and partly reduced the viability of mature biofilms. Desferrioxamine and DNase did not reduce biofilm formation. For most isolates, desferrioxamine and DNase did not offer any clear advantage over the use of antibiotics alone with respect to reducing the viability of Pseudomonas biofilms., Conclusions: Colistin, tobramycin and ciprofloxacin prevented biofilm formation by P. aeruginosa and reduced the viability of mature biofilms. For most isolates, there was no clear advantage of combining these antimicrobials with desferrioxamine or DNase., (© The Author(s) 2019. Published by Oxford University Press on behalf of the British Society for Antimicrobial Chemotherapy. All rights reserved. For permissions, please email: journals.permissions@oup.com.)

Whole-genome sequencing (WGS) makes it possible to determine the relatedness of bacterial isolates at a high resolution, thereby helping to characterize outbreaks. However, for Staphylococcus aureus , the accumulation of within-host diversity during carriage might limit the interpretation of sequencing data. In this study, we hypothesized the converse, namely, that within-host diversity can in fact be exploited to reveal the involvement of long-term carriers (LTCs) in outbreaks. We analyzed WGS data from 20 historical outbreaks and applied phylogenetic methods to assess genetic relatedness and to estimate the time to most recent common ancestor (TMRCA). The findings were compared with the routine investigation results and epidemiological evidence. Outbreaks with epidemiological evidence for an LTC source had a mean estimated TMRCA (adjusted for outbreak duration) of 243 days (95% highest posterior density interval [HPD], 143 to 343 days) compared with 55 days (95% HPD, 28 to 81 days) for outbreaks lacking epidemiological evidence for an LTC ( P = 0.004). A threshold of 156 days predicted LTC involvement with a sensitivity of 0.875 and a specificity of 1. We also found 6/20 outbreaks included isolates with differing antimicrobial susceptibility profiles; however, these had only modestly increased pairwise diversity (mean 17.5 single nucleotide variants [SNVs] [95% confidence interval {CI}, 17.3 to 17.8]) compared with isolates with identical antibiograms (12.7 SNVs [95% CI, 12.5 to 12.8]) ( P < 0.0001). Additionally, for 2 outbreaks, WGS identified 1 or more isolates that were genetically distinct despite having the outbreak pulsed-field gel electrophoresis (PFGE) pulsotype. The duration-adjusted TMRCA allowed the involvement of LTCs in outbreaks to be identified and could be used to decide whether screening for long-term carriage (e.g., in health care workers) is warranted. Requiring identical antibiograms to trigger investigation could miss important contributors to outbreaks., (Copyright © 2017 Gordon et al.)

Background: Cystic fibrosis lung disease is generally a diffuse process however rarely one lung may become particularly damaged through chronic collapse and consolidation resulting in end-stage bronchiectasis with relative sparing of the contralateral lung. This clinical situation is sometimes referred to as "destroyed lung". Lung resection surgery is seldom indicated in cystic fibrosis and the associated medical literature is relatively sparse., Case Presentation: A 14 year old boy was referred to our centre for lung transplantation assessment. He had a chronic history of complete collapse and consolidation of his entire right lung. This was causing severe morbidity in terms of a continuous requirement for intravenous antibiotics over the last year, poor exercise tolerance with forced expiratory volume in 1 s of 35-40% predicted and need for home tuition. He also had significant nutritional problems and gastrointestinal symptoms following a Nissen's fundoplication operation a year earlier. His nutritional status was firstly improved by the institution of jejunal feeding, which also greatly improved his distressing symptoms of nausea and wretching. After thorough multidisciplinary assessment the therapeutic option of performing a right pneumonectomy was considered due to relative sparing of the left lung, which demonstrated only mild bronchiectasis on computed tomography scan. This was performed uneventfully with a smooth peri-operative course. Targeted antimicrobials were used to treat the multiresistant organisms colonising his airways. Subsequently his quality of life, nutritional status and lung function all improved significantly and requirement for lung transplantation has been delayed., Conclusions: We report a successful outcome following pneumonectomy in a teenage boy with cystic fibrosis referred to our centre for lung transplantation assessment with chronic unilateral collapse and consolidation of his right lung. We believe that improvement of nutritional status pre-operatively and targeted antimicrobial therapy, all contributed to the smooth peri-operative course. Pneumonectomy can be a feasible option in this clinical situation in cystic fibrosis but the associated risks must be considered carefully on a case-by-case basis.

Two culture media were compared for their ability to isolate Clostridium difficile from environmental sites within a UK hospital. The media were cefoxitin-cycloserine-egg yolk agar plus lysozyme (CCEY/L) and chromID C. difficile. A wide range of environmental surfaces was sampled using sterile sponges (Polywipes) and these were inoculated on to both media. C. difficile was recovered from 105 of 496 sites (21%) using a combination of both media. The sensitivity of chromID C. difficile was 87.6% compared with 26.6% for CCEY/L (P < 0.0001). chromID C. difficile performed significantly better than CCEY/L for the recovery of C. difficile from the environment., (Copyright © 2012 The Healthcare Infection Society. Published by Elsevier Ltd. All rights reserved.)

During an 18-month period, 1606 stool specimens from laboratory-confirmed cases of Clostridium difficile infection in the North East of England were ribotyped using unrestricted polymerase chain reaction. Of these, 87.6% grew C. difficile on culture; 70% had one of 10 recognizable ribotypes of which 001, 106 and 027 were the most prevalent. The proportions of ribotypes 002 and 015 declined during the study period, whereas ribotypes 016 and 023 increased. Ribotype 005 was significantly more numerous in males and ribotype 027 was associated with significantly higher mean age. Our findings differ from national data derived from more selective testing., (Copyright © 2012 The Healthcare Infection Society. Published by Elsevier Ltd. All rights reserved.)

The aim of this study was to establish the antimicrobial activities of S-(3,4-dichlorobenzyl)isothiourea hydrochloride (A22) and a series of structurally related compounds against multidrug-resistant (MDR) bacteria. The minimum inhibitory concentrations (MICs) of 21 compounds were determined against 18 strains of pathogenic bacteria in addition to Pseudomonas aeruginosa (n=19) and Burkholderia cepacia complex (BCC) (n=20) isolated from the sputa of cystic fibrosis patients. Selected compounds were tested against further isolates, including P. aeruginosa (n=100), BCC (n=12) and Stenotrophomonas maltophilia (n=19). The interaction of S-(4-chlorobenzyl)isothiourea hydrochloride (C2) in combination with conventional antimicrobials was examined against 10 P. aeruginosa strains. Selected compounds were also tested against Enterobacteriaceae producing NDM-1 carbapenemase (n=64) and meticillin-resistant Staphylococcus aureus (MRSA) (n=37). Of the 21 compounds, 14 showed antimicrobial activity that was generally more pronounced against Gram-negative bacteria. Against P. aeruginosa, the most active compound was C2 [MIC for 50% of the organisms (MIC(50))=32μg/mL]. This compound was also the most active against BCC, with all isolates inhibited by 64μg/mL. For all ten strains of P. aeruginosa subjected to combination testing with C2 and conventional antimicrobials, a bactericidal effect was achieved with at least one combination. C2 and A22 both showed strong activity [MIC for 90% of the organisms (MIC(90))=4μg/mL] against Enterobacteriaceae that produced NDM-1 carbapenemase. Finally, S-(4-chlorobenzyl)-N-(2,4-dichlorophenyl)isothiourea hydrochloride showed good activity (MIC(90)=8μg/mL) against MRSA. This work establishes the activity of isothiourea derivatives against a broad range of clinically important MDR bacteria., (Copyright © 2011 Elsevier B.V. and the International Society of Chemotherapy. All rights reserved.)

Early infection is a recognised complication after lung transplantation in patients with cystic fibrosis (CF). Our centre uses multiple combination bactericidal testing (MCBT) when determining appropriate peritransplant prophylactic regimens. To evaluate our strategy, we compared the incidence of posttransplant infection in patients whose peritransplant antimicrobial regimens were determined using MCBT versus standard sensitivity testing. Patients with CF who were infected with Pseudomonas aeruginosa and underwent lung transplantations between 2000 and 2010 were included. Data was collected from clinical records and our microbiology database. Microorganisms cultured were mapped against antibiotic resistance, method of sensitivity testing, and antibiotics administered peritransplant. 129 patients were identified (mean age 28, male : female, 63 : 66). Fifty patients (38.8%) had antibiotics determined by MCBT. Two patients in the MCBT group developed septicaemia, 13 in the conventional group (P ≤ 0.05, 2-tailed Fisher's test). Sepsis was attributable to P. aeruginosa in one patient from the MCBT group and seven patients in the conventional group (P = 0.15). P. aeruginosa was recovered from the posttransplant pleural fluid of one patient who received MCBT-guided prophylaxis, six patients in the conventional group (P = 0.25). Patients given antibiotics based on MCBT had significantly lower rates of septicaemia and lower rates of empyema.

The Newcastle upon Tyne Hospitals NHS Foundation Trust (NuTH) implemented a seek and destroy (S&D) programme in 2006 to minimise meticillin-resistant Staphylococcus aureus (MRSA) colonisation and/or infection of patients. Using a phased introduction, all patient specialties were included in the scheme by September 2008, well in advance of the mandatory Department of Health, England (DoH) requirement for all patients to be screened. NuTH screens nose, throat and perineum samples from approximately 15,000 patients per month using a chromogenic culture method, showing a mean MRSA prevalence of 2.4%. Provision of seven-day microbiology and infection control services ensured that the turnaround time to prescribing decolonisation therapy was <24 h. Analysis of 168,073 results identified the necessity for inclusion of all three screening sites to maximise recovery of MRSA. Appraisal of the S&D policy demonstrated that MRSA detection rates did not increase despite an exponential increase in workload owing to mandatory inclusion of low risk areas in the screening programme. Review of data during a typical one-month period indicated that only seven day-case patients would not have been identified as MRSA carriers using our targeted S&D approach compared with the DoH universal screening. Detection of these additional patients incurred total laboratory costs of £20,000 and generated a further 4200 associated negative screens in one month alone. Our study indicates that a screening strategy based upon clinical risk is more pragmatic and more cost-effective than the universal programme currently required in England., (Copyright © 2011 The Healthcare Infection Society. Published by Elsevier Ltd. All rights reserved.)

Linezolid has been in general use in the UK since 2000. Although toxicity, particularly haematological and neurological, has been an issue, linezolid has proved to be an effective alternative to glycopeptides in the treatment of Gram-positive infections. Since its original licence for the treatment of skin and soft tissue infections and pneumonia, there have been reports of its successful use in the treatment of bone and joint infections, endocarditis, and other difficult-to-treat infections.

Background: Pre-operative infection with organisms from the Burkholderia cepacia complex (BCC), particularly B cenocepacia, has been linked with a poorer prognosis after transplantation compared to patients with cystic fibrosis (CF) without this infection. Therefore, many transplant centers do not list these patients for transplantation., Methods: We report the early and long-term results of a cohort of lung transplant recipients with CF and pre-operative BCC infection. Patients with pre-transplantation BCC infection were identified by case-note review. BCC species status was assigned by polymerase chain reaction (PCR)-based techniques. Survival rates were compared to recipients with CF without BCC infection. Survival rates in BCC subgroups were also compared, and then further analyzed pre- and post-2001, when a new immunosuppressive and antibiotic regime was introduced for such patients., Results: Two hundred sixteen patients with CF underwent lung transplantation and 22 had confirmed pre-operative BCC infection, with 12 of these being B cenocepacia. Nine B cenocepacia-infected recipients died within the first year, and in 8 BCC sepsis was considered to be the cause of death. Despite instituting a tailored peri-operative immunosuppressive and microbiologic care approach for such patients, post-transplantation BCC septic deaths occurred frequently in those with pre-transplantation B cenocepacia infection. In contrast, recipients infected with other BCC species had significantly better outcomes, with post-transplantation survival comparable to other recipients with CF., Conclusions: Mortality in patients with B cenocepacia infection was unacceptably high and has led to our center no longer accepting patients with this condition onto the lung transplant waiting list. Long-term survival in the non-B cenocepacia BCC group was excellent, without high rates of acute rejection or bronchiolitis obliterans syndrome (BOS) longer term, and these patients continue to be considered for lung transplantation., (Copyright © 2010 International Society for Heart and Lung Transplantation. Published by Elsevier Inc. All rights reserved.)

Rapid and effective methods for the isolation of Clostridium difficile from stool samples are desirable to obtain isolates for typing or to facilitate accurate diagnosis of C. difficile-associated diarrhea. We report on the evaluation of a prototype chromogenic medium (ID C. difficile prototype [IDCd]) for isolation of C. difficile. The chromogenic medium was compared using (i) 368 untreated stool samples that were also inoculated onto CLO medium, (ii) 339 stool samples that were subjected to alcohol shock and also inoculated onto five distinct selective agars, and (iii) standardized suspensions of 10 C. difficile ribotypes (untreated and alcohol treated) that were also inoculated onto five distinct selective agars. Two hundred thirty-six isolates of C. difficile were recovered from 368 untreated stool samples, and all but 1 of these strains (99.6%) were recovered on IDCd within 24 h, whereas 74.6% of isolates were recovered on CLO medium after 48 h. Of 339 alcohol-treated stool samples cultured onto IDCd and five other selective agars, C. difficile was recovered from 218 samples using a combination of all media. The use of IDCd allowed recovery of 96.3% of isolates within 24 h, whereas 51 to 83% of isolates were recovered within 24 h using the five other media. Finally, when they were challenged with pure cultures, all 10 ribotypes of C. difficile generated higher colony counts on IDCd irrespective of alcohol pretreatment or duration of incubation. We conclude that IDCd is an effective medium for isolation of C. difficile from stool samples within 24 h.

The mortality risk of prosthetic valve endocarditis is known to be increased in cases in which staphylococci are the causative organisms. Previous recommendations have concentrated on early surgical management of this condition, but there are now reports that these infections can be treated medically, thus leaving prosthetic material in situ. We describe a case of methicillin-resistant Staphylococcus aureus endocarditis on a bovine pericardial pulmonary valve that responded to antibiotic therapy without the need for surgical intervention.

Prosthetic joint replacement is increasingly used to alleviate pain and increase mobility. Bone and joint infections remain a therapeutic dilemma for healthcare providers in all fields. Antimicrobial agents combined with appropriate surgical techniques play a vital role in eradicating infections associated with prosthetic joints. The question still remains whether monotherapy or combination therapy is effective in this situation because there is a paucity of well-defined comparative studies. We reviewed in vitro and in vivo studies evaluating the effectiveness of various antimicrobial agents either as single agents or in combination.

This is the first structural elucidation of the lipooligosaccharide (LOS) endotoxin isolated from Burkholderia vietnamiensis, a clinically important member of Burkholderia cepacia complex, a group of over 10 opportunistic species that are highly problematic in cystic fibrosis. We have characterized a novel LOS structure extracted from two clonal strains of B. vietnamiensis isolated from a cystic fibrosis patient who underwent lung transplantation. Strains were selected from the pretransplantation and post-transplantation periods and endotoxin was extracted. Subsequent analysis interestingly revealed identical oligosaccharidic sequences, but variation in lipid A moieties. Further, both LOS fractions were tested for their immunostimulatory activity on human myelomonocytic U937 cells and for signaling on an HEK293 cell line stably expressing both TLR 4 and MD-2. We observed an increase in lipid A acylation and a resultant increase in biological activity in bio-reporter assays of TNF-alpha secretion in the post-transplantation strain.

Background: A novel chromogenic medium for isolation and identification of Pseudomonas aeruginosa from sputa of cystic fibrosis (CF) patients was evaluated and compared with standard laboratory methods., Methods: One hundred sputum samples from distinct CF patients were cultured onto blood agar (BA), Pseudomonas CN selective agar (CN) and a Pseudomonas chromogenic medium (PS-ID). All Gram-negative morphological variants from each medium were subjected to antimicrobial susceptibility testing, and identification using a combination of biochemical and molecular methods., Results: P. aeruginosa was isolated from 62 samples after 72 h incubation. Blood agar recovered P. aeruginosa from 56 samples (90.3%) compared with 59 samples (95.2%) using either CN or PS-ID. The positive predictive value of PS-ID (98.3%) was significantly higher than growth on CN (88.5%) for identification of P. aeruginosa (P<0.05)., Conclusions: PS-ID is a promising medium allowing for the isolation and simultaneous identification of P. aeruginosa from sputa of CF patients.

Aims: This study sought to evaluate the performance of two chromogenic media designed for the isolation of vancomycin-resistant enterococci (VRE) and compare them with a traditional bile-esculin medium for the isolation of VRE from stool samples., Methods and Results: A total of 285 stool samples were inoculated onto Chromogenic VRE Agar (AES VRE agar; AES Chemunex), chromID VRE (bioMérieux) and VRE Agar (Oxoid) both directly and also following broth enrichment. In total 18 strains of vancomycin-resistant Enterococcus faecium were recovered, including 17 harbouring the vanA gene and one with vanB. On direct culture, the sensitivity of the three media was 66.7%, 77.8% and 44.4% and after broth enrichment 66.7%, 83.3% and 77.8% using AES VRE Agar, chromID VRE and Oxoid VRE Agar respectively., Conclusions: All three media are useful tools for the isolation of VRE from stool samples. AES VRE Agar and bioMérieux chromID VRE are easier to use than Oxoid VRE Agar due to diffusion of black coloration from the latter., Significance and Impact of the Study: This is the first study to evaluate the performance of AES VRE Agar and the first to compare two media containing synthetic chromogens for the isolation of VRE.

In the present study, 4 patients with cystic fibrosis undergoing lung transplantation (from a total of 137) who developed fulminant pseudomembranous colitis are described. Initial presentation was variable and the mortality rate was 50% despite urgent colectomy. In one case the presenting abdominal distension was thought to be due to meconium ileus equivalent. It is concluded that Clostridium difficile colitis may be a difficult diagnosis in patients with cystic fibrosis and follows a fulminant course after lung transplantation.

The Burkholderia cepacia complex is a group of Gram-negative bacteria that are opportunistic pathogens for humans especially in cystic fibrosis patients. Lipopolysaccharide (LPS) molecules are potent virulence factors of Gram-negative bacteria organisms essential for bacterial survival. A complete analysis of the bacterial lipopolysaccharide structure to function relationship is required to understand the chemical basis of the inflammatory process. We have therefore investigated the structures of lipopolysaccharides from clonally identical Burkholderia multivorans strains (genomovar II) isolated pre- and post-lung transplantation through compositional analysis, mass spectrometry, and 2D NMR spectroscopy. We tested the LPS proinflammatory activity as a stimulant of human myelomonocytic U937 cell cytokine induction and assessed TLR4/MD2 signaling. Marked changes between the paired strains were found in the lipid A-inner core region. Such structural variations can contribute to the bacterial survival and persistence of infections despite the loss of a CF milieu following lung transplantation.

Background: Lung transplantation is an important option to treat patients with advanced cystic fibrosis (CF) lung disease. The outcomes of a large UK cohort of CF lung transplantation recipients is reported., Methods: Retrospective review of case notes and transplantation databases., Results: 176 patients with CF underwent lung transplantation at our centre. The majority (168) had bilateral sequential lung transplantation. Median age at transplantation was 26 years. Diabetes was common pretransplantation (40%). Polymicrobial infection was common in individual recipients. A diverse range of pathogens were encountered, including the Burkholderia cepacia complex (BCC). The bronchial anastomotic complication rate was 2%. Pulmonary function (forced expiratory volume in 1 s % predicted) improved from a pretransplantation median of 0.8 l (21% predicted) to 2.95 l (78% predicted) at 1 year following transplantation. We noted an acute rejection rate of 41% within the first month. Our survival values were 82% survival at 1 year, 70% at 3 years, 62% at 5 years and 51% at 10 years. Patients with BCC infection had poorer outcomes and represented the majority of those who had a septic death. Data are presented on those free from these infections. Bronchiolitis obliterans syndrome (BOS) and sepsis were common causes of death. Freedom from BOS was 74% at 5 years and 38% at 10 years. Biochemical evidence of renal dysfunction was common although renal replacement was infrequently required (<5%)., Conclusion: Lung transplantation is an important therapeutic option in patients with CF even in those with more complex microbiology. Good functional outcomes are noted although transplantation associated morbidities accrue with time.

A total of 200 antenatal high vaginal swabs were screened for the presence of group B Streptococcus (GBS) using a conventional culture method (recommended by Centers for Disease Control and Prevention). Screening was also performed by using a new chromogenic agar, chromID Strepto B, and by using the BD GeneOhm StrepB real-time polymerase chain reaction (PCR), which was performed directly on swabs without enrichment. Using a combination of all methods, we detected GBS in 101 samples. A total of 82 samples (81.2%) were positive using PCR, and 83 samples (82.2%) were confirmed as positive by culture (any method). PCR was more sensitive for detection of GBS than direct culture using any method (P < 0.0005). PCR was also more sensitive than any single enrichment method, but this difference was not statistically significant. With culture as a "gold standard", the PCR method showed a sensitivity of 77.1% and a positive predictive value of 79.3%. Of the culture-positive samples, significantly, more GBSs were detected by direct plating on chromID Strepto B than on selective sheep blood agar (67.5% versus 57% respectively, P < 0.02). After selective enrichment, 92.8% of GBS were isolated on chromID Strepto B compared with 89.2% isolated on sheep blood agar.

Objectives: To assess the utility of direct plating of whole sputa onto selective media as a means of identifying antimicrobial resistance in strains of Pseudomonas aeruginosa from the sputa of patients with cystic fibrosis (CF)., Methods: A total of 45 sputum samples from CF patients were cultured onto conventional culture media for isolation of P. aeruginosa and were also cultured directly onto Iso-Sensitest agar plates containing each of 10 antimicrobials incorporated at a 'breakpoint' concentration. A representative of each colonial type (morphotype) recovered from both routine media and selective media was tested for its susceptibility to 10 antimicrobials using a standard agar dilution MIC technique., Results: Of the samples shown to contain resistant strains, the proportion (%) detected using routine media and selective media, respectively, was: 42 and 100 for amikacin, 57 and 100 for gentamicin, 54 and 100 for tobramycin, 88 and 77 for aztreonam, 62 and 90 for ceftazidime, 70 and 97 for meropenem, 61 and 100 for piperacillin/tazobactam, 90 and 86 for temocillin, 66 and 100 for ticarcillin/clavulanic acid, and 80 and 90 for ciprofloxacin resistance. The increased rates of isolation on selective media were statistically significant (P < 0.05) for amikacin, gentamicin, tobramycin, meropenem, piperacillin/tazobactam and ticarcillin/clavulanic acid., Conclusions: For most antimicrobials, selection of colonies from conventional media for antimicrobial susceptibility testing provided a considerable underestimation of resistance in P. aeruginosa. The use of selective media for the culture of whole sputum was effective for the detection of resistant isolates of P. aeruginosa.

In 1990, an international grading scheme for the grading of pulmonary allograft rejection was adopted by the International Society for Heart and Lung Transplantation (ISHLT) and was modified in 1995 by an expanded group of pathologists. The original and revised classifications have served the lung transplant community well, facilitating communication between transplant centers with regard to both patient management and research. In 2006, under the direction of the ISHLT, a multi-disciplinary review of the biopsy grading system was undertaken to update the scheme, address inconsistencies of use, and consider the current knowledge of antibody-mediated rejection in the lung. This article summarizes the revised consensus classification of lung allograft rejection. In brief, acute rejection is based on perivascular and interstitial mononuclear infiltrates, Grade A0 (none), Grade A1 (minimal), Grade A2 (mild), Grade A3 (moderate) and Grade A4 (severe), as previously. The revised (R) categories of small airways inflammation, lymphocytic bronchiolitis, are as follows: Grade B0 (none), Grade B1R (low grade, 1996, B1 and B2), Grade B2R (high grade, 1996, B3 and B4) and BX (ungradeable). Chronic rejection, obliterative bronchiolitis (Grade C), is described as present (C1) or absent (C0), without reference to presence of inflammatory activity. Chronic vascular rejection is unchanged as Grade D. Recommendations are made for the evaluation of antibody-mediated rejection, recognizing that this is a controversial entity in the lung, less well developed and understood than in other solid-organ grafts, and with no consensus reached on diagnostic features. Differential diagnoses of acute rejection, airway inflammation and chronic rejection are described and technical considerations revisited. This consensus revision of the working formulation was approved by the ISHLT board of directors in April 2007.

Pseudomembranous colitis is an uncommon complication in patients with cystic fibrosis, despite the use of multiple high-dose antibiotic regimens and the frequency of hospital admissions. Four patients from a total of 137 patients with cystic fibrosis undergoing lung transplantation are described who developed fulminant pseudomembranous colitis. Initial presentation was variable and the mortality rate was 50% despite urgent colectomy. In one case the presenting abdominal distension was thought to be due to meconium ileus equivalent. It is concluded that Clostridium difficile colitis may be a difficult diagnosis in patients with cystic fibrosis and follows a fulminant course after lung transplantation.

Aims: To evaluate three previously unreported substrates for the detection of beta-glucosidase activity in clinically relevant bacteria and to compare their performance with a range of known substrates in an agar medium., Methods and Results: The performance of 11 chromogenic beta-glucosidase substrates was compared using 109 Enterobacteriaceae strains, 40 enterococci and 20 strains of Listeria spp. Three previously unreported beta-glucosides were tested including derivatives of alizarin, 3',4'-dihydroxyflavone and 3-hydroxyflavone. These were compared with esculin and beta-glucoside derivatives of 3,4-cyclohexenoesculetin, 8-hydroxyquinoline and five indoxylics. All substrates yielded coloured precipitates upon hydrolysis in agar. Alizarin-beta-D-glucoside was the most sensitive substrate tested and detected beta-glucosidase activity in 72% of Enterobacteriaceae strains and all enterococci and Listeria spp. The two flavone derivatives showed poor sensitivity with Gram-negative bacteria but excellent sensitivity with enterococci and Listeria spp., Conclusions: Alizarin-beta-d-glucoside is a highly sensitive substrate for detection of bacterial beta-glucosidase and compares favourably with existing substrates. beta-glucosides of 3',4'-dihydroxyflavone and 3-hydroxyflavone are effective substrates for the detection of beta-glucosidase in enterococci and Listeria spp., Significance and Impact of the Study: The data presented allow for informed decisions to be made regarding the optimal choice of beta-glucosidase substrate for detection of pathogenic and/or indicator bacteria.

Aims: To evaluate a new chromogenic agar as a screening medium for the isolation of Group B streptococci from high vaginal swabs from pregnant women., Methods and Results: The medium was evaluated with 195 high vaginal swabs referred for antenatal screening and compared with blood agar and Granada medium. The new chromogenic medium showed 100% sensitivity for the detection of Group B streptococci, and also showed a positive predictive value of 100%. Granada medium also showed excellent sensitivity and specificity and both media were superior to blood agar., Conclusions: The new chromogenic medium showed excellent performance for the detection of Group B streptococci from clinical samples., Significance and Impact of the Study: This is the first chromogenic medium described for the detection of Group B streptococci. The medium offers an effective and convenient alternative to conventional media, currently used in clinical laboratories.

Aims: Enzyme substrates based on 4-methylumbelliferone are widely used for the detection of Escherichia coli and enterococci in water, by detection of beta-glucuronidase and beta-glucosidase activity respectively. This study aimed to synthesize and evaluate novel umbelliferone-based substrates with improved sensitivity for these two enzymes., Methods and Results: A novel beta-glucuronide derivative based on 6-chloro-4-methylumbelliferone (CMUG) was synthesized and compared with 4-methylumbelliferyl-beta-D-glucuronide (MUG) using 42 strains of E. coli in a modified membrane lauryl sulfate broth. Over 7 h of incubation, the fluorescence generated from the hydrolysis of CMUG by E. coli was over twice that from MUG, and all of the 38 glucuronidase-positive strains generated a higher fluorescence with CMUG compared with MUG. Neither substrate caused inhibition of bacterial growth in any of the tested strains. Four beta-glucosidase substrates were also synthesized and evaluated in comparison with 4-methylumbelliferyl-beta-D-glucoside (MU-GLU) using 42 strains of enterococci in glucose azide broth. The four substrates comprised beta-glucoside derivatives of umbelliferone-3-carboxylic acid and its methyl, ethyl and benzyl esters. Glucosides of the methyl, ethyl and benzyl esters of umbelliferone-3-carboxylic acid, were found to be superior to MU-GLU for the detection of enterococci, especially after 18 h of incubation, while umbelliferone-3-carboxylic acid-beta-D-glucoside was inferior. However, the variability in detectable beta-glucosidase activity among the different strains of enterococci in short-term assays using the three carboxylate esters (7 h incubation) may compromise their use for rapid detection and enumeration of these faecal indicator bacteria., Conclusions: The beta-glucuronidase substrate CMUG appears to be a more promising detection system than the various beta-glucosidase substrates tested., Significance and Impact of the Study: The novel substrate CMUG showed enhanced sensitivity for the detection of beta-glucuronidase-producing bacteria such as E. coli, with a clear potential for application in rapid assays for the detection of this indicator organism in natural water and other environmental samples.

These guidelines have been produced following a literature review of the requirement for prophylaxis to prevent bacterial endocarditis following dental and surgical interventions. Recommendations are made based on the quality of available evidence and the consequent risk of morbidity and mortality for "at risk" patients.

These evidence-based guidelines have been produced after a literature review of the treatment and prophylaxis of methicillin-resistant Staphylococcus aureus (MRSA) infection. The guidelines were further informed by antibiotic susceptibility data on MRSA from the UK. Recommendations are given for the treatment of common infections caused by MRSA, elimination of MRSA from carriage sites and prophylaxis of surgical site infection. There are several antibiotics currently available that are suitable for use in the management of this problem and potentially useful new agents are continuing to emerge.

Long-term survival in lung transplantation is limited by the development of obliterative bronchiolitis, a condition characterised by inflammation, epithelial injury, fibroproliferation and obliteration of bronchioles leading to airflow obstruction. To investigate the role of the bronchial epithelium in the pathogenesis of obliterative bronchiolitis the current study aimed to establish primary bronchial epithelial cell cultures (PBEC) from lung allografts. Four to six bronchial brushings were obtained from sub-segmental bronchi of lung allografts. Cells were seeded onto collagen-coated plates and grown to confluence in bronchial epithelial growth medium. Bronchial brushings (n=33) were obtained from 27 patients. PBECs were grown to confluence from 12 out of 33 (39%) brushings. Failure to reach confluence was due to early innate infection. Bacteria were usually isolated from both bronchoalveolar lavage and culture media, but a separate population was identified in culture media only. Primary culture of bronchial epithelial cells from lung transplant recipients is feasible, despite a high rate of early, patient-derived infection. Latent infection of the allograft, identified only by bronchial brushings, may itself be a persistent stimulus for epithelial injury. This technique facilitates future mechanistic studies of airway epithelial responses in the pathogenesis of obliterative bronchiolitis.

Although many lung allograft recipients achieve long-term survival, there is a lack of published data regarding these patients' functional status and quality of life (QoL). We evaluated all 10-year survivors at our institution and, utilizing the SF-36 questionnaire, compared their QoL to population normative and chronic illness data. Twenty-eight (29%) of 96 patients survived > or =10 years following 11 single, 6 bilateral and 11 heart-lung procedures. At the most recent evaluation, median FEV(1) in single and double lung recipients was predicted to be 54% and 74%, respectively. Five (18%) patients had BOS score 0, 13 (46%) BOS 1, 5 (18%) BOS 2 and 5 (18%) BOS 3 and median time to BOS was 7 years. Four (14%) patients required renal replacement therapy. Three patients (11%) developed symptomatic osteoporosis, 2 (7%) post-transplant lymphoma and 1 (4%) an ischaemic stroke. Scores for physical function, role-physical/emotional and general health, but not mental health and bodily pain, were significantly lower compared to normative and chronic illness data. Energy and social-function scores were significantly lower than normative data alone. Long-term survival after lung transplantation is characterized by an absence or delayed development of BOS, low iatrogenic morbidity and preserved mental, but reduced physical health status.