Case Report: The Conundrum of What to Pick? Antibiotic Susceptibility Variability in Burkholderia cenocepacia in Cystic Fibrosis: Implications for Antibiotic Susceptibility Testing and Treatment.

Within cystic fibrosis microbiology, there is often mismatch between the antibiotic susceptibility result of an isolated bacterial pathogen and the clinical outcome, when the patient is treated with the same antibiotic. The reasoning for this remains largely elusive. Antibiotic susceptibility to four antibiotics (ceftazidime, meropenem, minocycline and trimethoprim-sulfamethoxazole) was determined in consecutive isolates (n = 11) from an adult cystic fibrosis patient, over a 63 month period. Each isolate displayed its own unique resistotype. The first isolate was sensitive to all four antibiotics, in accordance with Clinical and Laboratory Standards Institute methodology and interpretative criteria. Resistance was first detected at four months, showing resistance to ceftazidime and meropenen and intermediate resistance to minocycline and trimethoprim-sulfamethoxazole. Pan resistance was first detected at 18 months (resistotype IV), with three resistotypes (I, II and III) preceding this complete resistotype. The bacterium continued to display further antibiotic susceptibility heterogeneity for the next 45 months, with the description of an additional seven resistotypes (resistotypes V-XI). The Relative Resistance Index of this bacterium over the 63 month period showed no relationship between the development of antibiotic resistance and time. Adoption of mathematical modelling employing multinomial distribution demonstrated that large numbers of individual colony picks (>40/sputum), would be required to be 78% confident of capturing all 11 resistotypes present. Such a requirement for large numbers of colony picks combined with antibiotic susceptibility-related methodological problems creates a conundrum in biomedical science practice, in providing a robust assay that will capture antibiotic susceptibility variation, be pragmatic and cost-effective to deliver as a pathology service, but have the reliability to help clinicians select appropriate antibiotics for their patients. This study represents an advance in biomedical science as it demonstrates potential variability in antibiotic susceptibility testing with Burkholderia cenocepacia. Respiratory physicians and paediatricians need to be made aware of such variation by biomedical scientists at the bench, so that clinicians can contextualise the significance of the reported susceptibility result, when selecting appropriate antibiotics for their cystic fibrosis patient. Furthermore, consideration needs to be given in providing additional guidance on the laboratory report to highlight this heterogeneity to emphasise the potential for misalignment between susceptibility result and clinical outcome.

Burkholderia semiarida as Cause of Recurrent Pulmonary Infection in Immunocompetent Patient, China.

Burkholderia semiarida was previously identified solely as a plant pathogen within the Burkholderia cepacia complex. We present a case in China involving recurrent pneumonia attributed to B. semiarida infection. Of note, the infection manifested in an immunocompetent patient with no associated primary diseases and endured for >3 years.

When is Burkholderia cepacia complex truly eradicated in adults with cystic fibrosis? A 20-year follow up study.

BACKGROUND: Burkholderia cepacia complex (BCC) infection in cystic fibrosis (CF) is associated with increased morbidity and mortality. Current UK guidance recommends segregation of people with CF according to infection status. To date there is no universally agreed consensus on the number of negative samples or time interval since last isolation of BCC for eradication to be deemed successful. METHODS: All cases of new BCC isolation at Manchester Adult Cystic Fibrosis Centre were followed-up between May 2002-May 2022. The number of subsequent positive and negative sputum samples for BCC were recorded, as well as eradication treatment received. Eradication was deemed successful if there were ≥3 negative sputum samples and no further positive sputum samples for the same species and strain ≥12 months until the end of follow-up. RESULTS: Of 46 new BCC isolation, 25 were successfully eradicated and 21 resulted in chronic infection. 5 (16.7%) cases with exclusively negative sputum samples 6-12 months after initial isolation had subsequent samples that were culture-positive for BCC and 3 (10.7%) cases with exclusively negative sputum samples after 12-24 months had subsequent culture-positive samples. Cases where BCC was eradicated had a greater median number of days of eradication treatment (42, IQR 21-63) compared to those in whom BCC isolation resulted in chronic infection (28, IQR 14-42), p = 0.04. CONCLUSIONS: A cautious approach to segregation should be maintained after new isolation of BCC in CF, as some individuals with ≥3 negative samples 12-24 months after initial isolation had subsequent sputum samples culture-positive for BCC.

Efficacy of Antibiotic Bone Cement in the Treatment of Burkholderia cepacia Infection After Spinal Internal Fixation Surgery: Case Report and Literature Review.

BACKGROUND: In recent years, the number of spinal internal fixation operations has increased significantly, correlating with an elevated risk of postoperative surgical site infection and a rising incidence rate. While the conventional treatment approach involves surgical debridement combined with antibiotic administration, there is a notable gap in reported strategies for Burkholderia cepacia infection and patients exhibiting multidrug resistance. METHODS: Surgical site infection occurred in a patient following internal fixation surgery for thoracic vertebral fractures. Despite the application of systemic antibiotics and regular dressing changes, no improvement was observed. Bacterial culture and drug sensitivity experiments revealed a multidrug-resistant Burkholderia cepacia infection. Two comprehensive debridement procedures were performed along with continuous post-operative irrigation combined with antibiotic administration; however, no significant improvement was observed. The patient's infection was significantly controlled following treatment with vancomycin loaded bone cement. RESULTS: Following spinal internal fixation surgery, the management of a B. cepacian infection with multidrug resistance presented a significant challenge, despite the application of debridement procedures and systemic antibiotics. In this case, after 20 days of treatment with vancomycin-loaded bone cement, the patient's C-reactive protein level decreased to 54 mg/L, was normalized by February, and normal levels were maintained in the surgical area 1 month and 6 months after bone cement removal. CONCLUSIONS: The use of vancomycin-loaded bone cement proves effective in treating postoperative B. cepacian infection in a multidrug-resistant case following spinal internal fixation surgery.

Acidic pH modulates Burkholderia cenocepacia antimicrobial susceptibility in the cystic fibrosis nutritional environment.

IMPORTANCE: Burkholderia cenocepacia causes severe infections in cystic fibrosis (CF) patients. CF patients are prone to reoccurring infections due to the accumulation of mucus in their lungs, where bacteria can adhere and grow. Some of the antibiotics that inhibit B. cenocepacia in the laboratory are not effective for CF patients. A major contributor to poor clinical outcomes is that antibiotic testing in laboratories occurs under conditions that are different from those of sputum. CF sputum may be acidic and have increased concentrations of iron and zinc. Here, we used a medium that mimics CF sputum and found that acidic pH decreased the activity of many of the antibiotics used against B. cenocepacia. In addition, we assessed susceptibility to more than 500 antibiotics and found four active compounds against B. cenocepacia. Our findings give a better understanding of the lack of a relationship between susceptibility testing and the clinical outcome when treating B. cenocepacia infections.

Burkholderia cepacia complex as a cause of community acquired bacteremia in a young immuncompetent male.

Burkholderia cepacia complex (BCC) is a well-recognized cause of nosocomial infections. We describe here a young healthy male who presented with fever and chest pain with ECG changes of acute pericarditis. Two sets of blood cultures at separate timings grew gram negative bacilli identified as BCC by molecular methods. The patient responded to intravenous ceftazidime despite high ceftazidime MIC's. The source of infection was probably contaminated nasal spray/nasal saline wash which he used after a balloon sinoplasty procedure one month ago. Issues related to accurate identification and susceptibility testing of BCC are also discussed.

Burkholderia cepacia infections at sites other than the respiratory tract: A large case series from a tertiary hospital in Madurai.

Sparsely reported extrapulmonary Burkholderia cepacia complex (Bcc) infections highlights the importance of this study. This was a retrospective chart review of 37 patients with extrapulmonary Bcc infections admitted between December 2019 and July 2022 in a tertiary hospital. Males accounted for 70% of cases. 78% had atleast one underlying comorbid illness. Among 37 isolates, 22 were from blood, others include exudates, urine and peritoneal fluid. Susceptibility rates of ceftazidime, meropenem, minocycline, cotrimoxazole and levofloxacin were 88, 88, 70, 65.7 and 56.7% respectively. Eleven died of septic shock and 24 patients (64.8%) had good outcomes, while two were lost to followup.

Phage therapy in a lung transplant recipient with cystic fibrosis infected with multidrug-resistant Burkholderia multivorans.

BACKGROUND: There is increased interest in bacteriophage (phage) therapy to treat infections caused by antibiotic-resistant bacteria. A lung transplant recipient with cystic fibrosis and Burkholderia multivorans infection was treated with inhaled phage therapy for 7 days before she died. METHODS: Phages were given via nebulization through the mechanical ventilation circuit. Remnant respiratory specimens and serum were collected. We quantified phage and bacterial deoxyribonucleic acid (DNA) using quantitative polymerase chain reaction, and tested phage neutralization in the presence of patient serum. We performed whole genome sequencing and antibiotic and phage susceptibility testing on 15 B. multivorans isolates. Finally, we extracted lipopolysaccharide (LPS) from two isolates and visualized their LPS using gel electrophoresis. RESULTS: Phage therapy was temporally followed by a temporary improvement in leukocytosis and hemodynamics, followed by worsening leukocytosis on day 5, deterioration on day 7, and death on day 8. We detected phage DNA in respiratory samples after 6 days of nebulized phage therapy. Bacterial DNA in respiratory samples decreased over time, and no serum neutralization was detected. Isolates collected between 2001 and 2020 were closely related but differed in their antibiotic and phage susceptibility profiles. Early isolates were not susceptible to the phage used for therapy, while later isolates, including two isolates collected during phage therapy, were susceptible. Susceptibility to the phage used for therapy was correlated with differences in O-antigen profiles of an early versus a late isolate. CONCLUSIONS: This case of clinical failure of nebulized phage therapy highlights the limitations, unknowns, and challenges of phage therapy for resistant infections.

Burkholderia cepacia infection associated with sickle cell disease: An uncommon entity.

Burkholderia, a multidrug-resistant Gram-negative bacteria, is an uncommon cause of infection mostly in immunocompromised patients with a clinical profile very similar to tuberculosis. The most common conditions associated with this organism are cystic fibrosis and chronic granulomatous diseases. Bacteremia with it occurs in patients who are chronically ill and associated with significant morbidity and mortality. We are reporting here a case of perisplenic intra-abdominal abscess caused by Burkholderia cepacia in a patient with sickle cell disease (SCD).

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.

Burkholderia cepacia causing liver and splenic abscess: Two case reports.

Burkholderia cepacia infections are common among immunocompromised patients but multiple reports have shown that it can affect immunocompetent patients also. We are reporting two patients with multiple liver and splenic abscesses caused by Burkholderia cepacia. First case is a 54-year-old diabetic male presenting with fever, abdominal pain, bilateral lower limb weakness, and incontinence of urine. Second case is a 41-year-old male presenting with fever and confusion. Both had liver and splenic abscesses. Pus aspirated from the abscesses grew Burkholderia cepacia. Both responded to cotrimoxazole. Our case report emphasizes growing incidence of Burkholderia cepacia in immunocompetent patients.

Activity of ETX0462 toward Some Burkholderia spp.

Burkholderia cepacia complex (Bcc) and Burkholderia gladioli are opportunistic human pathogens that are inherently multidrug resistant, limiting treatment options for infections. Here, a novel diazabicyclooctane, ETX0462, was evaluated for activity against Bcc and B. gladioli. Ninety-eight percent of the isolates examined in this study were susceptible. ETX0462 was found to demonstrate in vitro activity superior to that of currently available treatment options (e.g., trimethoprim-sulfamethoxazole and ceftazidime).

Clinical characteristics, drug resistance and death risk factors of Burkholderia cepacia infection in hematopoietic stem cell transplant patients.

BACKGROUND: Burkholderia cepacia (BC) has been detected more and more in infected patients in recent years. However, as a high-risk population, the clinical characteristics and prognosis of BC infection in hematopoietic stem cell transplantation (HSCT) patients have not been reported. The purpose of this study is to obtain data that will help fill in the gaps in this field, provide evidence for reducing the mortality rate of BC infection in HSCT patients, and guide the use of antibiotics in the future. METHODS: Electronic medical records of patients with BC infection who underwent HSCT in Xiangya Hospital of Central South University from September 1, 2015 to August 31, 2021 were collected. At the same time, 1:1 case-control matching was conducted according to gender, age and disease type. Comparisons between patients with/without BC infection and respiratory failure were made respectively, and the sensitivity of BC to five clinically commonly used antibiotics was also evaluated. Univariate and multivariate analyses were performed to identify independent risk factors for death. RESULTS: The most common site of BC infection in HSCT patients was the lung (75%). Although BC infection rate (3.74%) and antibiotic resistance were not significant, it was closely associated with a higher risk of death (P = 0.022), which even further increased to 90.9% when combined with respiratory failure (P = 0.008). Procalcitonin > 10 µg/L (HR = 40.88, 95% CI 6.51-256.63, P = 0.000) and septic shock (HR = 4.08, 95% CI 1.02-16.33, P = 0.047) were two independent risk factors for death. CONCLUSION: HSCT patients with BC infection are in critical condition, and the management of respiratory infection should be especially strengthened to improve the prognosis of these patients.

Case Report: Community-Acquired Burkholderia cepacia Pneumonia of a Patient with Pulmonary Tuberculosis.

Community-acquired Burkholderia cepacia pneumonia is rare. We report a 29-year-old female who suffered pulmonary tuberculosis and developed community-acquired Burkholderia cepacia pneumonia, which was confirmed by the culture of the pulmonary tissue. The patient received antitubercular therapy. Meanwhile, she was treated with meropenem and minocycline. The patient was followed up for 6 months, and she achieved complete absorption of lung lesions.

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.

Burkholderia cepacia Infections at Sites Other than the Respiratory Tract: A Large Case Series from a Tertiary Referral Hospital in Lebanon.

OBJECTIVES: The Burkholderia cepacia complex (Bcc), which was originally thought to be a single species, represents a group of 24 distinct species that are often resistant to multiple antibiotics, and usually known to cause life-threatening pulmonary infections in cystic fibrosis patients. Herein we describe a series of non-respiratory Bcc infections, the risk factors and epidemiologic factors, in addition to the clinical course. PATIENTS AND METHODS: This is a retrospective chart review of 44 patients with documented B. cepacia infections isolated from sites other than the respiratory tract admitted between June 2005 and February 2020 to the American University of Beirut Medical Center (AUBMC), a tertiary referral hospital for Lebanon and the Middle East region. The epidemiological background of these patients, their underlying risk factors, the used antibiotic regimens, and the sensitivities of the B. cepacia specimens were collected. RESULTS: The majority of the Bcc infections (26/44, 59.1%) were hospital-acquired infections. The most common nationality of the patients was Iraqi (18/44, 40.9%), and the most common site of infection was bacteremia (17/44, 38.6%), followed by skin and soft tissues infections (16/44, 36.4%) and vertebral osteomyelitis (8/44, 18.2%). Most of the isolated B. cepacia were susceptible to ceftazidime, carbapenems, followed by TMP-SMX. Patients responded well to therapy with good overall outcome. CONCLUSIONS: Bcc can cause infections outside the respiratory tract, mostly as hospital-acquired infections and in immunocompromised patients. Most patients were referred from countries inflicted by wars raising the possibility of a potential role of conflicts which need to be investigated in future studies. Directed therapy according to susceptibility results proved effective in most patients.

Managing Pulmonary Infection in Adults With Cystic Fibrosis: Adult Cystic Fibrosis Series.

Cystic fibrosis (CF) is characterized by chronic airway infection and progressive respiratory decline. Historically, a narrow spectrum of bacterial pathogens was believed to comprise the bulk of respiratory infections in CF, with Haemophilus influenzae and Staphylococcus aureus dominating childhood infections, and Pseudomonas aeruginosa or, less commonly, a member of the Burkholderia cepacia complex becoming the dominant infecting organism in adulthood. Today, the landscape is changing for airway infection in CF. The prevalence of "less typical" gram-negative bacterial infections are rising due to a number of factors: the CF population is aging; new therapies are being introduced; antibiotic usage is increasing; diagnostic tests are evolving; and taxonomic changes are being made as new bacterial species are being discovered. Less is known about the clinical relevance and evidence for treatment strategies for many of the other lower prevalence organisms that are encountered in CF. The aim of this article was to discuss the current evidence and recommended strategies for treating airway infection in CF, focusing on bacterial infections.

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.

Clinical characteristics and outcomes of non-cystic fibrosis patients with Burkholderia cepacia complex bacteremia at a medical center in Taiwan.

BACKGROUND: Burkholderia cepacia complex (BCC) represents a group of multidrug-resistant gram-negative bacteria that cause infections among immunocompromised hosts. Bacteremia occurs in patients who are chronically ill and is associated with substantial morbidity and mortality. The aim of this study was to investigate the clinical characteristics and outcomes of BCC bacteremic patients without cystic fibrosis. METHODS: We conducted a retrospective study at the National Taiwan University Hospital. Adults with BCC bacteremia from January 2015 to May 2019 were enrolled. The primary outcome was 14-day mortality. Multivariable logistic regression was performed for outcome analysis. RESULTS: One-hundred and ninety-five patients were analyzed and their mean age was 67 years. Over 95% of the BCC isolates were susceptible to trimethoprim/sulfomethoxazole (TMP/SXT). Levofloxacin resistance rates were high, with only 25.1% of isolates being susceptible. Pairwise comparisons were made between different definitive regimens including meropenem-monotherapy, ceftazidime-monotherapy, levofloxacin-monotherapy, TMP/SXT-monotherapy, tigecycline-monotherapy as well as combination versus monotherapy. No regimen was significantly associated with survival in our study. Multivariable logistic regression showed that the Pitt bacteremia score (adjust odds ratio [aOR],1.46; 95% confidence interval [CI],1.19-1.79; p < 0.001), underlying metastatic cancer (aOR, 2.73; 95% CI, 1.01-7.39; p = 0.047), inappropriate definitive treatment independently predicted greater 14-day mortality (aOR, 8.21; 95% CI, 2.49-27.08; p < 0.001). CONCLUSIONS: No single regimen is associated with improved mortality. After adjusting for other potential confounders, our data suggest selection of an appropriate antibiotic provide better clinical outcomes among patients with BCC bacteremia.

Disruption of biofilms and killing of Burkholderia cenocepacia from cystic fibrosis lung using an antioxidant-antibiotic combination therapy.

Cystic fibrosis (CF) is a disease caused by mutations in the cystic fibrosis transmembrane conductance regulator (CFTR). The resulting chloride and bicarbonate imbalance produces a thick, static lung mucus. This mucus is not easily expelled from the lung and can be colonised by bacteria, leading to biofilm formation. CF lung infection with Burkholderia cepacia complex (BCC), particularly the subspecies B. cenocepacia, results in higher morbidity and mortality. Patients infected with BCC can rapidly progress to "cepacia syndrome", a fatal necrotising pneumonia. The aim of this study was to identify whether a combination therapy (CT) of selected antioxidants and antibiotics significantly disrupts B. cenocepacia biofilms and to determine the optimum CT level for treatment. Using controlled in vitro spectrophotometry, colony-forming unit and microscopy assays, three antioxidants (N-acetylcysteine [NAC], glutathione and vitamin C) and three antibiotics (ciprofloxacin, ceftazidime and tobramycin) were screened and assessed for their ability to disrupt the early and mature biofilms of six B. cenocepacia CF isolates. A combination of NAC and ciprofloxacin produced a statistically significant biofilm disruption in all strains tested, with growth inhibition (>5-8 log10) observed when exposed to 4890 or 8150 µg/mL NAC in combination with 32 or 64 µg/mL ciprofloxacin. NAC-mediated biofilm disruption may be aided by the acidic pH of NAC at higher concentrations. This study showed that NAC is an effective disruptor that reduces the necessity for high concentrations of antibiotic. Further research will focus on the host toxicity and efficacy in ex vivo CF models.