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.

Evaluation of CHROMagar™ B. cepacia agar for the detection of Burkholderia cepacia complex species from sputum samples of patients with cystic fibrosis.

INTRODUCTION: Burkholderia cepacia complex (BCC) are non-fermenting Gram-negative bacteria that can chronically colonize the lungs of people with cystic fibrosis (pwCF), causing a severe and progressive respiratory failure, post-transplant complications and epidemic outbreaks. Therefore, rapid and accurate identification of these bacteria is relevant for pwCF, in order to facilitate early eradication and prevent chronic colonization. However, BCCs are often quite difficult to detect on culture media as they have a slow growth rate and can be hidden by other fast-growing microorganisms, including Pseudomonas aeruginosa and filamentous fungi. MATERIAL AND METHODS: We evaluated the sensitivity of CHROMagar™ B. cepacia agar using 11 isolates from a well-characterized BCC collection, using BCA agar (Oxoid, UK) as a gold standard. We also studied 180 clinical sputum samples to calculate positive (PPV) and negative (NPV) predictive values. Furthermore, we used three of the well-characterized BCC isolates to determine the limit of detection (LOD). RESULTS: Eleven isolates grew on CHROMagar™ B. cepacia at 37ºC after 48 h. The NPV and PPV of CHROMagar™ B. cepacia were 100% and 87.5%, respectively. The LOD of CHROMagar™ B. cepacia was around 1 × 103 CFU/ml, requiring a ten-fold dilution lower bacterial load than BCA for BCC detection. CONCLUSION: CHROMagar™ B. cepacia agar proved to have a very good sensitivity and specificity for the detection of clinical BCCs. Moreover, the chromogenic nature of the medium allowed us to clearly differentiate BCC from other Gram-negative species, filamentous fungi and yeasts, thereby facilitating the identification of contaminants.

Burkholderia thailandensis Isolated from Infected Wound, Southwest China, 2022.

We report a clinical isolate of Burkholderia thailandensis 2022DZh obtained from a patient with an infected wound in southwest China. Genomic analysis indicates that this isolate clusters with B. thailandensis BPM, a human isolate from Chongqing, China. We recommend enhancing monitoring and surveillance for B. thailandensis infection in both humans and livestock.

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.

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.

Identification of Burkholderia cepacia Complex by PCR: A Simple Way.

United States Pharmacopeia (USP) General Chapter <60> for the detection of Burkholderia cepacia complex (Bcc) members in nonsterile products became official in December 2019. This isolation method requires confirmation of the identity of any growth found on Burkholderia cepacia Selective Agar (BCSA) by additional identification tests (refer to the Interpretation section). This article presents a singleplex polymerase chain reaction (PCR) method to rapidly confirm the membership of any microbial grown on BCSA (and other nutrient medium) in the Bcc group. This method is cost effective as it does not require expensive equipment or reagents; therefore, it can be easily adopted in the industry without an important investment. We validated this singleplex PCR Bcc identification method with previously published PCR primers with an expanded panel of 37 clinical and environmental Bcc isolates. The sources and repositories of these Bcc isolates include contaminated health products and medical devices, patients infected with cystic fibrosis, the National Microbiology Laboratory (NML) internal strain bank, and the American Type Culture Collection (ATCC). All 37 isolates that belong to the Bcc tested positive using our confirmatory identification method. Twenty-two negative controls including four isolates belonging to the genus Burkholderia tested negative as expected. Our work indicates that this singleplex PCR is an efficient confirmatory method for Bcc identification, and it can successfully supplement USP <60> for Bcc isolates identification found in pharmaceutical products.

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).

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.

Burkholderia vietnamiensis infection in a haematological unit: Case series and review of literature of this new emerging pathogen.

Burkholderia vietnamiensis causes opportunistic infection in immunocompromised individuals. It closely resembles other non-fermentative Gram-negative bacteria. Accuracy in diagnosis has improved with the use of new modalities. Here, we describe four patients of lymphoblastic disorder on chemotherapy, who presented with fever due to blood stream infection. Multidrug resistant B. vietnaminensis was isolated in blood culture and identified using MALDI-TOF MS. All of them responded to a switch in antibiotic therapy based on sensitivity reports. This is the first case series from North India highlighting the importance of this less known organism as an important pathogen in immunocompromised patients.

Molecular Research Comparing the Probabilities of Burkholderia Cepacia Bacterium Diagnosis Procedures.

Burkholderia cepacia is found as part of the B. cepacia complex (Bcc), a collection of highly pathogenic organisms. The Bcc is present almost everywhere in nature; however, it is most prevalent in damp settings, plant roots, and soils. Moreover, Bcc is a major source of morbidity and death in patients due to its high intrinsic antibiotic resistance. The present study aims to isolate and identify gram-negative aerobic bacteria from clinical samples derived from a variety of pathological diseases and investigate the bacterium's virulence factors and genes. The current study included 250 specimens collected from patients suffering from diabetic foot ulcers, urine, burn, wound, sputum, and discharge from the eyes. The samples were collected from both sexes with the age range of 1-75 years. The recorded data showed that males had a higher frequency of infection (79.2%) than females (52%). The results revealed that 7.6% of infected females were between 1-15 years old, while 22% of infected males were aged between 31-45 years. In addition, 26.8% of infected patients (both males and females) were aged between 31-45 years.

Rapid detection of Burkholderia cepacia complex carrying the 16S rRNA gene in clinical specimens by recombinase-aided amplification.

The Burkholderia cepacia complex (BCC) is a group of opportunistic pathogens, including Burkholderia cepacia, Burkholderia multivorans, Burkholderia vietnamiensis and Burkholderia ambifaria, which can cause severe respiratory tract infections and lead to high mortality rates among humans. The early diagnosis and effective treatment of BCC infection are therefore crucial. In this study, a novel and rapid recombinase-aided amplification (RAA) assay targeting the 16S rRNA gene was developed for BCC detection. The protocol for this RAA assay could be completed in 10 min at 39°C, with a sensitivity of 10 copies per reaction and no cross-reactivity with other pathogens. To characterize the effectiveness of the RAA assay, we further collected 269 clinical samples from patients with bacterial pneumonia. The sensitivity and specificity of the RAA assay were 100% and 98.5%, respectively. Seven BCC-infected patients were detected using the RAA assay, and three BCC strains were isolated from the 269 clinical samples. Our data showed that the prevalence of BCC infection was 2.60%, which is higher than the 1.40% reported in previous studies, suggesting that high sensitivity is vital to BCC detection. We also screened a patient with B. vietnamiensis infection using the RAA assay in clinic, allowing for appropriate treatment to be initiated rapidly. Together, these data indicate that the RAA assay targeting the 16S rRNA gene can be applied for the early and rapid detection of BCC pathogens in patients with an uncharacterized infection who are immunocompromised or have underlying diseases, thereby providing guidance for effective treatment.

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.

Diabetic foot infection caused by bacteria of the Burkholderia cepacia complex: report of an unusual case and a scoping literature review.

Burkholderia cepacia complex (BCC) is group of widespread gram-negative bacillus organized in over 20 phylogenetically distinct bacterial species. According to previous studies, BCC species pathogens are widely reported in patients with cystic fibrosis (CF), but not in individuals with diabetes mellitus (DM). In this case report, a 42-year-old male patient with DM and a foot infection caused by BCC is presented. The patient was hospitalized after antibiotic treatment failure and improved after two surgical debridement procedures and a high-dose extended infusion (EI) of meropenem. The team of vascular surgeons and the infectious disease specialists worked fervently to solve the case. Finally, a scoping review was conducted to map BCC infections in patients with DM.

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.

Diagnostic methods and identification challenges experienced in a Burkholderia contaminans outbreak occurred in a tertiary care centre.

BACKGROUND: Recently, a novel species contaminans belonging to the family Burkholderia cepacia complex (Bcc) is rising as a hospital pathogen. Detection of Burkholderia contaminans, a member of Bcc can be done only by MALDI TOF and sequencing techniques. We report the diagnostic challenges faced in an outbreak of bacteremia due to B. contaminans grown in diltiazem vials. METHOD: The department of microbiology notified the infection control team about a cluster of eleven patients with B. contaminans isolated from blood culture. An outbreak investigation was initiated by performing environmental surveillance and sterility testing of solutions given for the patients. Routine phenotypical methods for identification of species followed by MALDI-TOF and sequencing was performed to identify the pathogen. RESULTS: All the patients detected with B. contaminans were having cardiac disease and received diltiazem. Sterility testing of diltiazem vials given for the patient and an unopened vial of same batch has grown B. contaminans. Clonal typing has confirmed the sequence similarities between patient and solution isolates. CONCLUSION: Due to diagnostic challenge in identifying the species of Bcc, MALDI TOF and clonal typing remains the key diagnostic tools available to detect Bcc species at an earliest especially in an outbreak.

Burkholderia cepacia complex bacteremia outbreaks among non-cystic fibrosis patients in the pediatric unit of a university hospital.

BACKGROUND: Burkholderia cepacia complex (Bcc) comprises multi-drug resistant, Gram-negative, motile, and aerobic bacteria. Bcc causes severe nosocomial infections particularly in patients with intravascular catheters and in those with cystic fibrosis. We studied a Bcc outbreak in non-cystic fibrosis patients. METHODS: We analyzed data from six patients hospitalized at our center. Blood cultures identified as infectious were incubated onto 5% blood sheep agar, chocolate agar, and eosin methylene blue (EMB) agar. We examined possible sites that could be sources of infection at the clinic. We confirmed isolations with pulsed-field gel electrophoresis (PFGE) tests. RESULTS: The first patient was hospitalized due to left renal agenesis, urinary tract infection, and renal failure. Bcc was isolated in blood cultures obtained due to high fever on the third day of hospitalization. We stopped new patient hospitalizations after detecting Bcc in blood cultures of other five patients. We did not detect further positive specimens obtained from other clinic and the patient rooms. PFGE patterns were similar in all clinical isolates of Bcc indicating that the outbreak had originated from the source. CONCLUSIONS: Bcc infection should be considered in cases of nosocomial outbreaks of multi-drug resistant organisms that require hospitalization at intensive care units. Control measures should be taken for prevention of nosocomial infections and required investigations should be done to detect the source of infection.

SARS-CoV-2 and Burkholderia cenocepacia infection in a patient with Cystic Fibrosis: An unfavourable conjunction?

The effects of the concomitant infection by COVID-19 and Burkholderia cepacia (Bc) in CF are not known. We describe the case of a 34 years woman with CF, colonized by Bc and found SARS-CoV2 positive. In the first hospital week she suffered acute respiratory failure and chest imaging showed interstitial involvement and multiple thickenings. She was treated with antibiotics, dexamethasone, remdesivir and heparin, with gradual improvement and discharge at day 20th. The reciprocal role of SARS-CoV-2 and Bc, their potential interactions and the contribution of the individual therapies to the favourable outcome are unclear. It is debatable whether it was SARS-CoV2 that triggered a Bc pulmonary exacerbation or if the chronic Bc infection facilitated the development of a COVID-19 more aggressive than usually seen in CF. If the latter hypothesis were confirmed by similar cases, Bc colonization should be regarded as a risk factor for severe COVID-19 expression in CF.

A glycoengineered antigen exploiting a conserved protein O-glycosylation pathway in the Burkholderia genus for detection of glanders infections.

We recently described a protein O-glycosylation pathway conserved in all species of the Burkholderia genus that results in the synthesis and incorporation of a trisaccharide glycan to membrane-exported proteins. Here, we exploited this system to construct and evaluate a diagnostic tool for glanders. Burkholderia mallei, the causative agent of glanders, is a highly infectious and fatal zoonotic pathogen that infects horses, mules, donkeys, and occasionally humans. A highly sensitive and specific diagnostic tool is crucial for the control, elimination, and eradication of B. mallei infections. We constructed plasmids carrying synthetic genes encoding a modified, previously unannotated Burkholderia glycoprotein containing three glycosylation sequons fused to the cholera toxin B-subunit. The resulting proteins were glycosylated in the B. cenocepacia K56-2 parental strain, but not in glycosylation-deficient mutants, as determined by SDS-PAGE and fluorescent lectin blots. One of these glycoproteins was used as an antigen in ELISA and western blots to screen a panel of serum samples collected from glanders-infected and healthy horses, which were previously investigated by complement fixation test and indirect ELISA based on a semi-purified fraction of B. mallei. We show that ELISA and western blot assays based on our glycoprotein antigen provide 100% specificity, with a sensitivity greater than 88%. The glycoprotein antigen was recognized by serum samples collected from patients infected with B. pseudomallei, B. mallei, B. multivorans, and B. cenocepacia. Our results indicate that protein O-glycosylation in Burkholderia can be exploited as a biomarker for diagnosis of Burkholderia-associated infections.