Survival following Burkholderia cepacia sepsis in a patient with cystic fibrosis treated with corticosteroids

Cepacia syndrome in cystic fibrosis: A systematic review of the literature and possible new perspectives in treatment

BACKGROUND

Cepacia syndrome (CS) is an acute, necrotizing pneumonia with a high mortality rate, occurring in patients with cystic fibrosis (CF) infected with Burkholderia cepacia complex (BCC). Due to its low incidence, data on this condition are limited.

METHODS

We conducted a systematic review of the reported cases of CS by searching MEDLINE, Embase and the Cochrane Library to improve knowledge of this rare but potentially lethal condition.

RESULTS

We included 15 eligible articles, describing 18 cases (9 females) of CS. Median age at onset was 22 years (range: 10-60 years); median time to CS after first infection by BCC was 5 years (range: 1-26 years). Burkholderia cenocepacia was the most frequently reported causative agent. All patients received intravenous antibiotic treatment (most frequently including cotrimoxazole), while inhaled antibiotics were used in five patients (27.8%). Immunosuppressant agents were the most commonly prescribed supportive treatment (n = 7, 38.9%). Half of the patients died (9/18, 50%).

CONCLUSIONS

This study describes epidemiological, clinical characteristics, and prognosis of CS cases reported over the last 24 years. CS is a rare yet severe complication of BCC infection in patients with CF, which occurs several years after BCC colonization and has a negative outcome in 50% of the patients. Data are too scanty to identify the most effective therapeutic approach.

Management of Cepacia syndrome in an immunocompetent non-cystic fibrosis adult patient

Burkholderia cepacia complex (BCC) is nonfermenting, Gram-negative bacteria known to cause high morbidity and mortality. They commonly affect patients with cystic fibrosis (CF) and are often missed in those without, despite being fatal if left untreated. We report a case of cepacia syndrome in a 42-year-old, immunocompetent man without CF who initially presented with sepsis secondary to pneumonia. Multiple isolates from blood, synovial fluid, and wound swabs grew BCC. Treatment options and management strategies remain poorly understood for BCC in general and in cases without CF in specific. We successfully treated the patient using a combination of intravenous and inhalational antibiotics. This case report elaborates on the disease presentation, investigations, and management strategy employed to treat this rare infection.

Management of Cepacia Syndrome With a Combination of Intravenous and Inhaled Antimicrobials in a Non-Cystic Fibrosis Pediatric Patient

Burkholderia cepacia complex (Bcc) is an opportunistic pathogen, posing little risk to healthy individuals. The presentation of Bcc can vary from a virtually asymptomatic chronic infection, to an acute, life-threatening necrotizing pneumonia, acute respiratory distress syndrome, and bacteremia (cepacia syndrome) associated with a mortality rate up to 75%. We present the successful treatment of a 17-year-old male with chronic granulomatous disorder who presented with cepacia syndrome and confirmed Bcc pneumonia using a novel antimicrobial approach. Despite initial IV antimicrobial therapy, our patient continued to decline, developing hypotension requiring pressor support and eventually extracorporeal membrane oxygenation. An aggressive, multimechanistic approach including the combination of nebulized tobramycin, IV sulfamethoxazole-trimethoprim, ceftazidime, enteral minocycline, and corticosteroids was implemented. This multimechanistic antimicrobial approach in combination with systemic corticosteroids led to the successful treatment of cepacia syndrome in the setting of necrotizing pneumonia due to B cepacia with full respiratory recovery. We suggest that in patients with cepacia syndrome who continue to decline despite IV antimicrobial therapy, using multiple antimicrobial mechanisms of action may improve clinical outcomes.

Macrophage activation syndrome/haemophagocytic lymphohistiocytosis secondary to Burkholderia cepacia complex septicaemia in an elderly female carrier of X-linked chronic granulomatous disease with extreme lyonisation: 'cepacia syndrome' revisited

X-linked carriers of chronic granulomatous disease (CGD) may become phenotypically affected if substantial skewing from lyonisation occurs. We describe a 73-year-old female carrier with an overt CGD phenotype due to skewed lyonisation, complicated by macrophage activation syndrome (MAS)/haemophagocytic lymphohistiocytosis (HLH) secondary to Burkholderiacepacia complex septicaemia that was successfully treated with a combination of three antibiotics, an antifungal, granulocyte colony stimulating factor, intravenous immune globulin (IVIG) and ciclosporin. Fully phenotypic immunodeficiency is possible in X-linked CGD carriers when skewed lyonisation occurs, rendering such patients to all the same sequelae of CGD such as MAS/HLH. MAS/HLH should be thoroughly excluded when evaluating 'cepacia syndrome' in non-CGD patients.

Clinical and in vitro evidence for the antimicrobial therapy in Burkholderia cepacia complex infections

Treatment of infections caused by Burkholderia cepacia complex (Bcc) in cystic fibrosis (CF) patients poses a complex problem. Bcc is multidrug-resistant due to innate and acquired mechanisms of resistance. As CF patients receive multiple courses of antibiotics, susceptibility patterns of strains from CF patients may differ from those noted in strains from non-CF patients. Thus, there was a need for assessing in vitro and clinical data to guide antimicrobial therapy in these patients. A systematic search of literature, followed by extraction and analysis of available information from human and in vitro studies was done. The results of the analysis are used to address various aspects like use of antimicrobials for pulmonary and non-pulmonary infections, use of combination versus monotherapy, early eradication, duration of therapy, route of administration, management of biofilms, development of resistance during therapy, pharmacokinetics-pharmacodynamics correlations, therapy in post-transplant patients and newer drugs in Bcc-infected CF patients.

Exaggerated inflammatory responses mediated by Burkholderia cenocepacia in human macrophages derived from Cystic fibrosis patients

Cystic fibrosis (CF) is accompanied with heightened inflammation worsened by drug resistant Burkholderia cenocepacia. Human CF macrophage responses to B. cenocepacia are poorly characterized and variable in the literature. Therefore, we examined human macrophage responses to the epidemic B. cenocepacia J2315 strain in order to identify novel anti-inflammatory targets. Peripheral blood monocyte derived macrophages were obtained from 23 CF and 27 non-CF donors. Macrophages were infected with B. cenocepacia J2315 and analyzed for cytokines, cytotoxicity, and microscopy. CF macrophages demonstrated significant increases in IL-1β, IL-10, MCP-1, and IFN-γ production in comparison to non-CF controls. CF patients on prednisone exhibited globally diminished cytokines compared to controls and other CF patients. CF macrophages also displayed increased bacterial burden and cell death. In conclusion, CF macrophages demonstrate exaggerated IL-1β, IL-10, MCP-1, and IFN-γ production and cell death during B. cenocepacia infection. Treatment with corticosteroids acutely suppressed cytokine responses.

Hopanoid production is required for low-pH tolerance, antimicrobial resistance, and motility in Burkholderia cenocepacia

Hopanoids are pentacyclic triterpenoids that are thought to be bacterial surrogates for eukaryotic sterols, such as cholesterol, acting to stabilize membranes and to regulate their fluidity and permeability. To date, very few studies have evaluated the role of hopanoids in bacterial physiology. The synthesis of hopanoids depends on the enzyme squalene-hopene cyclase (Shc), which converts the linear squalene into the basic hopene structure. Deletion of the 2 genes encoding Shc enzymes in Burkholderia cenocepacia K56-2, BCAM2831 and BCAS0167, resulted in a strain that was unable to produce hopanoids, as demonstrated by gas chromatography and mass spectrometry. Complementation of the Δshc mutant with only BCAM2831 was sufficient to restore hopanoid production to wild-type levels, while introducing a copy of BCAS0167 alone into the Δshc mutant produced only very small amounts of the hopanoid peak. The Δshc mutant grew as well as the wild type in medium buffered to pH 7 and demonstrated no defect in its ability to survive and replicate within macrophages, despite transmission electron microscopy (TEM) revealing defects in the organization of the cell envelope. The Δshc mutant displayed increased sensitivity to low pH, detergent, and various antibiotics, including polymyxin B and erythromycin. Loss of hopanoid production also resulted in severe defects in both swimming and swarming motility. This suggests that hopanoid production plays an important role in the physiology of B. cenocepacia.

Akt-mediated proinflammatory response of mononuclear phagocytes infected with Burkholderia cenocepacia occurs by a novel GSK3β-dependent, IκB kinase-independent mechanism

The environmental bacterium Burkholderia cenocepacia causes opportunistic lung infections in immunocompromised individuals, particularly in patients with cystic fibrosis. Infections in these patients are associated with exacerbated inflammation leading to rapid decay of lung function, and in some cases resulting in cepacia syndrome, which is characterized by a fatal acute necrotizing pneumonia and sepsis. B. cenocepacia can survive intracellularly in macrophages by altering the maturation of the phagosome, but very little is known on macrophage responses to the intracellular infection. In this study, we have examined the role of the PI3K/Akt signaling pathway in B. cenocepacia-infected monocytes and macrophages. We show that PI3K/Akt activity was required for NF-κB activity and the secretion of proinflammatory cytokines during infection with B. cenocepacia. In contrast to previous observations in epithelial cells infected with other Gram-negative bacteria, Akt did not enhance IκB kinase or NF-κB p65 phosphorylation, but rather inhibited GSK3β, a negative regulator of NF-κB transcriptional activity. This novel mechanism of modulation of NF-κB activity may provide a unique therapeutic target for controlling excessive inflammation upon B. cenocepacia infection.

Entry of Burkholderia organisms into respiratory epithelium: CFTR, microfilament and microtubule dependence

BACKGROUND

The pathogenesis of infection with Burkholderia cepacia complex (Bcc) organisms may be linked to its capacity to invade respiratory epithelium.

METHODS

An antibiotic exclusion assay was used to study B. dolosa AU4459 and B. cenocepacia J2315 invasion into wild-type (WT) and CFTR-deficient respiratory epithelial cells. Inhibitors were used to evaluate Bcc invasion dependency on host microtubule (mt) and microfilament (mf) systems.

RESULTS

B. dolosa entered WT-CFTR cells with 5-fold greater efficiency than CFTR deficient cells (25% vs 5%, respectively). Invasion dropped to <0.5% after either mf or mt inhibition. B. cenocepacia entered WT (0.05%) and CFTR-deficient cells (0.07%) with similarly low efficiencies, which significantly decreased with either mf or mt inhibition (0.008% and 0.002%, respectively).

CONCLUSION

B. dolosa and B. cenocepacia enter respiratory epithelial cells in a mf and mt dependent fashion. Mutated CFTR leads to less internalization of B. dolosa, but not B. cenocepacia.

Lack of MyD88 protects the immunodeficient host against fatal lung inflammation triggered by the opportunistic bacteria Burkholderia cenocepacia

Burkholderia cenocepacia is an opportunistic pathogen of major concern for cystic fibrosis patients as well as immunocompromised cancer patients and transplant recipients. The mechanisms by which B. cenocepacia triggers a rapid health deterioration of the susceptible host have yet to be characterized. TLR and their key signaling intermediate MyD88 play a central role in the detection of microbial molecular patterns and in the initiation of an effective immune response. We performed a study to better understand the role of TLR-MyD88 signaling in B. cenocepacia-induced pathogenesis in the immunocompromised host, using an experimental murine model. The time-course of several dynamic parameters, including animal survival, bacterial load, and secretion of critical inflammatory mediators, was compared in infected and immunosuppressed wild-type and MyD88(-/-) mice. Notably, when compared with wild-type mice, infected MyD88(-/-) animals displayed significantly reduced levels of inflammatory mediators (including KC, TNF-alpha, IL-6, MIP-2, and G-CSF) in blood and lung airspaces. Moreover, despite a higher transient bacterial load in the lungs, immunosuppressed mice deficient in MyD88 had an unexpected survival advantage. Finally, we showed that this B. cenocepacia-induced life-threatening infection of wild-type mice involved the proinflammatory cytokine TNF-alpha and could be prevented by corticosteroids. Altogether, our findings demonstrate that a MyD88-dependent pathway can critically contribute to a detrimental host inflammatory response that leads to fatal pneumonia.

Suppurative mediastinitis secondary to Burkholderia cepacia in a patient with cystic fibrosis

Burkholderia cepacia is an important opportunistic pathogen among patients with cystic fibrosis (CF); it is associated with deterioration of lung function, poor outcome following lung transplantation and increased mortality. Fever, an elevated white blood cell count, weight loss and an often fatal deterioration in pulmonary function characterize a particular clinical course, termed "Cepacia syndrome". The present case report describes a 40-year-old man with CF who developed Cepacia syndrome complicated by suppurative mediastinitis, from which B cepacia was isolated. Despite optimal medical and surgical therapy, this patient succumbed to his illness. Those caring for patients with CF should be aware of this potentially catastrophic complication of B cepacia infection, especially in the setting of Cepacia syndrome.

Infection-Induced Kinin B1Receptors in Human Pulmonary Fibroblasts: Role of Intact Pathogens and p38 Mitogen-Activated Protein Kinase-Dependent Signaling

Kinin B(1) receptors (B(1)R) are involved in many pathophysiological processes, and its expression is up-regulated in inflammatory pulmonary disease. Although bacteria can generate kinin peptides, the molecular signaling mechanisms regulating B(1)R during infection by intact pathogens is unknown. The serious opportunistic clinical isolate Burkholderia cenocepacia (B. cen.) belongs to the important B. cepacia complex (Bcc) of gram-negative pathogens that rapidly causes fatal pulmonary disease in hospitalized and immunocompromised patients and those with cystic fibrosis. We demonstrate here that B. cen. infection induced a rapid increase in B(1)R mRNA (1 h) proceeded by an increase in B(1)R protein expression (2 h), without affecting B(2) receptor expression in human pulmonary fibroblasts. The B(1)R response was dose-dependent and maximal by 6 to 8 h (3- to 4-fold increase), however, brief B. cen. infection could sustain B(1)R up-regulation. In contrast, nonclinical Bcc phytopathogens were much less B(1)R inducive. The protein synthesis inhibitor cycloheximide and transcriptional inhibitor actinomycin D abrogated the B(1) response to B. cen. indicating de novo B(1)R synthesis. B. cen. activated p38 mitogen-activated protein kinase (MAPK), and blocking p38 MAPK with the specific inhibitor 4-(4-fluorophenyl)-2-(4-methylsulfinylphenyl)-5-(4-pyridyl)1H-imidazole (SB 203580) dramatically reduced B. cen.-induced B(1)R. Furthermore, B. cen. regulation of B(1)R was diminished by the anti-inflammatory glucocorticoid dexamethasone. In conclusion, this study is the first demonstration that infection with intact pulmonary pathogens like B. cen. positively modulates the selective expression of B(1)R. Thus, providing evidence that B(1)R regulation may be an important and novel mechanism in the inflammatory cascade in response to chronic pulmonary infection and disease.

Pro-inflammatory effects of Burkholderia cepacia on cystic fibrosis respiratory epithelium

Burkholderia cepacia causes pulmonary infection with high mortality in cystic fibrosis (CF) patients which is likely to involve interaction with respiratory epithelium. In this study the pro-inflammatory properties of B. cepacia were examined using a range of respiratory epithelial cell lines. B. cepacia and cell-free culture supernatants were used to stimulate cell lines with (SigmaCFTE29o- and IB3) and without (A549) the CF transmembrane conductance regulator mutation (CFTR), together with corrected cell lines (C38 and S9). Interleukin (IL)-6 and IL-8, but not GM-CSF or IL-1beta, were released from all the cell lines whereas PGE(2) (prostaglandin E(2)) was released from the A549, IB3 and S9 cell lines only. Nuclear factor (NF)-kappaB activation preceded cytokine release and suppression of NF-kappaB activity diminished cytokine release. These studies indicated that B. cepacia secretory products are potent pro-inflammatory agents for respiratory epithelium and suggest functional CFTR is not required for cytokine or prostanoid responses.

Burkholderia cepacia-induced IL-8 gene expression in an alveolar epithelial cell line: signaling through CD14 and mitogen-activated protein kinase

Burkholderia cepacia is a prevalent pulmonary pathogen in patients with cystic fibrosis (CF). The lung pathology observed in patients with CF is postulated to be due to an overexpression of chemokines. This study investigated the induction of the neutrophil chemoattractant chemokine IL-8 and the signaling pathways activated by B. cepacia-infected human lung epithelial A549 (HLE) cells. Cells were infected with B. cepacia (genomovar III of the B. cepacia complex), and reverse transcriptase-PCR and ELISA for the cytokines were performed. B. cepacia (multiplicity of infection > or =4:1) induced HLE cells to significantly secrete IL-8 in a more potent manner than the predominant CF pathogen Pseudomonas aeruginosa (multiplicity of infection > or =64:1). IL-8 secretion by B. cepacia-infected HLE cells was abrogated by the gene transcription inhibitor actinomycin D and the protein translation inhibitor cycloheximide, confirming that B. cepacia-induced IL-8 secretion was mediated through de novo protein synthesis. Treatment of B. cepacia with proteinase K failed to down-regulate IL-8 secretion; furthermore, IL-8 secretion by B. cepacia-infected HLE cells was abrogated by > or =80% in the presence of anti-CD14 [specific lipopolysaccharide (LPS) receptor] antibody, thus suggesting that the IL-8-inducing component of B. cepacia was LPS and therefore dependent on CD14. The p38 mitogen-activated protein kinase (MAPK) inhibitor and the extracellular signal-regulated kinase MAPK inhibitor significantly abrogated IL-8 secretion by B. cepacia-infected HLE cells (SB203580, > or =80% inhibition; PD98059, > or =30% inhibition). In conclusion, B. cepacia-induced IL-8 secretion in A549 airway epithelial cells is more potent than P. aeruginosa; is mediated through LPS, which is CD14 dependent; and involves activation of the p38 and ERK MAPK pathways.

Infection control recommendations for patients with cystic fibrosis: microbiology, important pathogens, and infection control practices to prevent patient-to-patient transmission

Infection Control Recommendations for Patients With Cystic Fibrosis: Microbiology, Important Pathogens, and Infection Control Practices to Prevent Patient-to-Patient Transmissionupdates, expands, and replaces the consensus statement,Microbiology and Infectious Disease in Cystic Fibrosispublished in 1994. This consensus document presents background data and evidence-based recommendations for practices that are intended to decrease the risk of transmission of respiratory pathogens among CF patients from contaminated respiratory therapy equipment or the contaminated environment and thereby reduce the burden of respiratory illness. Included are recommendations applicable in the acute care hospital, ambulatory, home care, and selected non-healthcare settings. The target audience includes all healthcare workers who provide care to CF patients. Antimicrobial management is beyond the scope of this document.