Prosthetic valve endocarditis secondary to Burkholderia cepacia

Prosthetic valve endocarditis is a catastrophic complication of cardiac valve replacement and is associated with high mortality rates. Endocarditis due to Burkholderia cepacia (B. Cepacia) is rare but serious, leading to valve dysfunction and heart failure. B. Cepacia is resistant to multiple antibiotics which lead to frequent treatment failures. Two cases of B. Cepacia prosthetic valve endocarditis are reviewed.     

Chronic Burkholderia cepacia bronchiectasis in a non-cystic fibrosis individual

Infection with Burkholderia cepacia due to socialcontact is well described in patients with cystic fibrosis. However,social transmission to non-cystic fibrosis individuals or chroniccolonisation in non-cystic fibrosis individuals has not been described.A report of B cepacia bronchiectasis is presented where apreviously healthy mother of two cystic fibrosis children colonisedwith B cepacia became infected by the same epidemicstrain. The implications of this for parents, siblings, and partners ofindividuals with cystic fibrosis are discussed.

     

Burkholderia cepacia genomovar III and Burkholderia vietnamiensis double infection in a cystic fibrosis child.

Herein we report a case of a cystic fibrosis child who was simultaneously infected with Burkholderia cepacia genomovar III and Burkholderia vietnamiensis. After antimicrobial therapy only B. cepacia genomovar III persisted.     

洋葱伯克霍尔德菌血流感染危险因素及其同源性

目的探讨洋葱伯克霍尔德菌血流感染（BSI）的危险因素及其同源性。 方法收集绍兴市人民医院204年1月至2016年12月血流感染者中分离到的洋葱伯克霍尔德菌,应用脉冲场凝胶电泳（PFGE）揭示菌株间的同源性。同时分析洋葱伯克霍尔德菌BSI者的临床资料,以非洋葱伯克霍尔德菌BSI者作为对照组,探讨洋葱伯克霍尔德菌BSI的危险因素,并以是否存活作为预后判定标准,对洋葱伯克霍尔德菌BSI进行单因素和多因素Logistic回归分析,分析影响预后的相关因素。 结果32株洋葱伯克霍尔德菌共分为7个克隆株,其中克隆A 15株,克隆B 8株,克隆C 3株,克隆D 2株和克隆E各2株,克隆F和克隆G各1株。32例洋葱伯克霍尔德菌BSI者中,12例死亡,病死率为37.5%。非洋葱伯克霍尔德菌BSI者77例,多因素Logistic回归分析发现年龄、重症监护病房（ICU）住院时间> 2周、APACHE Ⅱ评分和菌株外排泵基因的存在均为洋葱伯克霍尔德菌BSI的独立危险因素（OR = 8.835、6.353、6.679和5.606,P均< 0.05）。 结论血流感染洋葱伯克霍尔德菌主要在ICU病房流行,存在克隆传播现象。年龄、ICU住院时间大于2周、APACHE Ⅱ评分和菌株外排泵基因的存在患者更易导致洋葱伯克霍尔德菌血流感染。     

Cross infection between cystic fibrosis patients colonised with Burkholderia cepacia

Whilst patient to patient spread of the respiratory pathogenBurkholderia cepacia is well recognised between patientswith cystic fibrosis, prompting a strict segregation policy, cross colonisation between cystic fibrosis patients already infected withB cepacia has not been described and surveys show a very low incidence of patients with more than one strain. Five adult cysticfibrosis patients with B cepacia are presented who became cross colonised with a second B cepacia (UK epidemic)strain, four of whom then died, three from the cepacia syndrome. These cases show that, amongst segregated patients, cross colonisation withdifferent B cepacia strains is possible, and even in these patients the acquisition of the UK epidemic strain may have a fataloutcome. In future it may be necessary to segregate cystic fibrosispatients colonised with the UK epidemic strain from all other patientswith cystic fibrosis.

     

Outcome of Burkholderia cepacia colonisation in an adult cystic fibrosis centre

BACKGROUND: Colonisation with Burkholderia cepacia is a poor prognostic indicator in subjects with cystic fibrosis (CF), but outcome prediction is impossible since patients are colonised by different strains with differing pathogenicity. The clinical course of a large cohort of CF patients colonised with UK epidemic (ET12) B cepacia was followed for 5 years and compared with that of the remaining patients in the clinic. METHODS: Pulmonary function, nutritional state, and lung pathogen colonisation were recorded for 5 years before December 1997 or death for all 107 patients who had attended the Liverpool adult CF clinic since 1993. For each patient a time line from study entry to date of death or 1997 was constructed. In 1993 potential risk factors including age and sex were subjected to Cox proportional hazards analysis using the end point of mortality as the outcome variable. The analysis was supplemented by time varying covariables that described the change in FEV(1), BMI, and colonisation status across time, and the excess risk associated with B cepacia colonisation was calculated. Subsequently, in those patients who died between 1993 and 1997, predictive factors for death were compared within groups using complete 5 year data. RESULTS: Thirty seven patients had been colonised by epidemic B cepacia and these patients had four times the mortality of the remainder (p<0.01). In 1993 univariate predictors of mortality were age (alive 19.6 (0.64) v dead 23.8 (1.44); p<0.005) and baseline FEV(1) (alive 68.6 (2.5)% predicted v dead 43.2 (4.8)%; p<0.001) with a trend for BMI (p=0.07). However, following time varying covariate Cox proportional hazards analysis, only lower FEV(1) (hazards ratio 1.1, 95% confidence limits 1.06 to 1.14; p<0.001) and colonisation with B cepacia (hazards ratio 7.92, confidence limits 2.65 to 23.69; p<0.001) were identified as significant factors for death. Surviving B cepacia patients had similar initial lung function to the remaining surviving patients but had an accelerated loss of lung function over the study period (colonised -1.9% predicted per year v non-colonised -0.3% predicted per year; p<0.05). Deceased patients colonised with B cepacia had better spirometric results than the remaining deceased patients 5 years before death (p<0.05) but lost lung function at a greater rate than non-colonised patients (colonised -6.2% predicted per year v non-colonised -1.9% predicted per year; p<0.05). CONCLUSIONS: This study confirms the excess mortality associated with epidemic B cepacia colonisation and shows that those with poor spirometric values are at the greatest risk.     

Exopolysaccharides produced by clinical strains belonging to the Burkholderia cepacia complex

BackgroundIn the frame of a research line dedicated to better clarify the role of exopolysaccharides (EPS) in bacterial virulence, EPS produced by species of the Burkholderia cepacia complex (Bcc), namely Burkholderia multivorans, Burkholderia cenocepacia, and a Bcc member of undetermined genomovar, all isolated at the Cystic Fibrosis Regional Centre of Florence (Italy), were investigated for they structural properties.MethodsThree strains of B. multivorans, three of B. cenocepacia and one of a Bcc member of undetermined genomovar were isolated from CF patients. The reference strains C1576 and J2315, for genomovar II and III, respectively, were included in the study. The bacteria were grown on solid media, the exopolysaccharides produced were purified, and their structures were determined. In addition, sugar analysis of sputum samples was accomplished to search for EPS produced in vivo.ResultsSix strains out of seven produced the exopolysaccharide cepacian, while one strain of B. multivorans produced a completely different polymer, previously known in the literature as PS1. Two strains synthesised very small amounts of EPS. No definitive evidence for the presence of cepacian in sputum samples was found.ConclusionsMost strains examined produced abundant amounts of polysaccharides. Cepacian was the most common EPS isolated and its production was not associated to a particular genomovar.     

Clinical outcome of Burkholderia cepacia complex infection in cystic fibrosis adults.

BACKGROUND: The Burkholderia cepacia complex (BCC) is one of the most important groups of organisms infecting cystic fibrosis (CF) patients. The aim of the study was to examine how infection with BCC affects clinical outcome. METHODS: Nineteen CF adults infected with BCC and 19 controls infected with Pseudomonas aeruginosa were studied over a 4-year period. The best forced expiratory volume in 1 s (FEV(1)) and body mass index (BMI) for each year were recorded and annual rate of decline calculated. RESULTS: The BCC infected group displayed a significantly greater reduction of FEV(1) and BMI compared to the P. aeruginosa infected group (p=0.001 and p=0.009, respectively). Sixteen patients infected with a single Burkholderia cenocepacia strain had a significantly greater rate of FEV(1) decline compared to those infected with Burkholderia multivorans (n=3) or P. aeruginosa (p=0.01 and p<0.0001, respectively). The rate of BMI decline was significantly greater in patients infected with B. cenocepacia compared to those with P. aeruginosa (p=0.007), but not significantly different in those with B. multivorans (p=0.29). CONCLUSION: BCC infection is associated with an accelerated decline in pulmonary function and BMI. Infection with a single B. cenocepacia strain was associated with a more rapid decline in lung function than those infected with either B. multivorans or P. aeruginosa.     

Temocillin in the treatment of Burkholderia cepacia infection in cystic fibrosis.

BACKGROUND: Infections due to Burkholderia cepacia complex (Bcc) strains increase morbidity and mortality in cystic fibrosis (CF). Some transplant centres reject Bcc infected patients. We reviewed the results in patients treated with i.v temocillin. METHODS: Twenty-three patients who received 38 courses of temocillin (1988-1998) were identified from the CF database at Royal Brompton Hospital. In three patients' data were inadequate; therefore analysis was done in 20. Outcome was measured as improvement, deterioration or no change (compared to admission) in the following categories: clinical (temperature, dyspnoea, sputum volume, chest pain), physiological (FEV1, FVC, oxygen saturation) and inflammatory markers (WBC, ESR, CRP). Patients who improved in two categories were classified as having improved. Antibiotic sensitivities and outcome were recorded. RESULTS: In 18 of 32 courses (56.25%) improvement occurred. The organism (Bcc) in eight patients' sputum became resistant (three died). The antibiotics was changed in five patients with Bcc strains sensitive to temocillin because of no improvement and one patient due to allergy (rash). The average time to the next i.v antibiotic was 41 days. Eight patients died (in three the Bcc strain was resistant to temocillin). Fourteen patients with Bcc were transplanted and eight patients survived. Another patient who developed Bcc infection post-operatively, failing to respond to temocillin. CONCLUSIONS: These results suggest the potential benefit of i.v temocillin in CF patients with Bcc for exacerbations and at the time of transplantation.     

Survival After Lung Transplantation of Cystic Fibrosis Patients Infected with Burkholderia cepacia Complex

Within the Burkholderia cepacia complex (Bcc), B. cenocepacia portends increased mortality compared with other species. We investigated the impact of Bcc infection on mortality and re-infection following lung transplant (LT). Species designation for isolates from Bcc-infected patients was determined using 16S rDNA and recA gene analyses. Of 75 cystic fibrosis patients undergoing LT from September 1992 to August 2002, 59 had no Bcc and 16 had Bcc (including 7 B. cenocepacia ) isolated in the year before LT. Of the latter, 87.5% had Bcc recovered after transplantation, and all retained their pretransplant strains. Survival was 97%, 92%, 76% and 63% for noninfected patients; 89%, 89%, 67% and 56% for patients infected with Bcc species other than B. cenocepacia; and 71%, 29%, 29% and 29% for patients with B. cenocepacia (p = 0.014) at 1 month, 1 year, 3 years and 5 years, respectively. Patients infected with B. cenocepacia before transplant were six times more likely to die within 1 year of transplant than those infected with other Bcc species (p = 0.04) and eight times than noninfected patients (p < 0.00005). Following LT, infection with Bcc species other than B. cenocepacia does not significantly impact 5-year survival whereas infection with B. cenocepacia pretransplant is associated with decreased survival.     

洋葱伯克霍尔德氏菌L68邻苯二酚2,3-双加氧酶基因克隆、表达和纯化

采用自行设计的引物,从洋葱伯克霍尔德氏菌L68中PCR扩增得到phnE（邻苯二酚2,3-双加氧酶）基因,亚克隆到高表达载体pET 32a上,转入表达菌株中.经双向测序,证实构建过程中未出现突变.重组子经IPTG诱导后,可以表达有活性的重组双加氧酶.选择26 ℃进行重组蛋白诱导.薄层扫描显示,表达重组蛋白总量最高可占总蛋白的64.92%.利用金属螯合层析对重组蛋白进行了一步纯化,SDS-PAGE结果显示,重组蛋白纯度达到95%.     

Reliability of multilocus sequence typing of the Burkholderia cepacia complex in cystic fibrosis.

INTRODUCTION: Infection with the Burkholderia cepacia complex is an important cause of morbidity and mortality in cystic fibrosis (CF). We investigated the molecular clock speed of the seven genes used in the multilocus sequence typing (MLST) scheme for these bacteria. METHODS: At least two isolates, separated by months to years, from each of 20 patients were typed using MLST. In total 41 isolates, providing 128 isolate-years, were analyzed. Mutation and recombination rates were estimated assuming a Poisson distribution. RESULTS: Out of 20 patients, 15 had no change in sequence type over time (mean 7.07 years, range 1.09 to 14.24). One patient had strain replacement. Three patients had evidence of recombination involving one of the seven housekeeping genes, and one patient had evidence of recombination of two genes. The mutation rate was estimated as 2.36x10(-6) per nucleotide per year (50% confidence limit) and 1.02x10(-5) per nucleotide per year (upper 95% confidence limit). The rate of nucleotide changes due to recombination events was estimated as 0.676 to 0.839 per year (95% confidence limits). CONCLUSIONS: B. cepacia complex housekeeping genes have a slow molecular clock speed and MLST provides a robust and reliable typing technique for isolates from this complex. A low rate of point mutation was found, with a higher rate of recombination events, in keeping with previous cross-sectional epidemiological data. The study also demonstrated, for the first time, recombination in a longitudinal in vivo study.     

Evaluating the alginate oligosaccharide (OligoG) as a therapy for Burkholderia cepacia complex cystic fibrosis lung infection

OligoG has previously shown potentiation of aztreonam against Burkholderia cepacia complex (Bcc) through biofilm disruption. A randomized, double-blind, placebo-controlled cross-over design was used to evaluate safety and efficacy of inhaled OligoG as a therapy for Bcc-infected CF patients taking aztreonam. Subjects received OligoG (1050 mg daily) or matching placebo for 28-days. Of 14 subjects completing the study, 8 showed a mean decrease in total bacterial CFU's (0.82 log10) after OligoG treatment. There was a reduction in mean Bcc CFU's (2.19 log10) after OligoG treatment but this was not statistically significant. Rheology analysis showed improvements in phase-angle after OligoG, but there was no statistically significant improvement in lung function parameters. Six out of 12 QoL summary scores showed relative improvement after OligoG treatment compared to placebo. There was a favourable safety profile for OligoG. Potential for reducing Bcc warrants further investigation of OligoG for the treatment of infection in CF.