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Introduction: The Burkholderia cepacia complex encompasses a group of gram-negative opportunistic pathogens that cause chronic lung infections in people with cystic fibrosis. Distinct from other respiratory pathogens, Burkholderia causes a unique clinical disease in a subset of patients known as 'cepacia syndrome', fulminant pneumonia accompanied by bacteraemia and sepsis with a mortality rate of up to 75%. Due to the bacteraemia associated with this disease, the mechanisms that allow Burkholderia to resist the bactericidal effects of serum complement-depending killing are vital. Antibodies usually promote serum killing; however, we have described 'cloaking antibodies', specific for lipopolysaccharides that paradoxically protect serum-sensitive bacteria from complement-mediated lysis. Cloaking antibodies that protect Pseudomonas aeruginosa have been found in 24%-41% of patients with chronic lung diseases. The presence of these antibodies is also associated with worse clinical outcomes. Here, we sought to determine the relevance of cloaking antibodies in patients with Burkholderia infection. Methods: Twelve Burkholderia spp. were isolated from nine pwCF and characterised for susceptibility to healthy control serum. Patient serum was analysed for the titre of the cloaking antibody. The ability of the patient serum to prevent healthy control serum (HCS) killing of its cognate isolates was determined. Results: We found that several of the Burkholderia strains were shared between patients. Ten of the 12 isolates were highly susceptible to HCS killing. Four of nine (44%) patients had cloaking antibodies that protected their cognate strain from serum killing. Depleting cloaking antibodies from patient serum restored HCS killing of Burkholderia isolates. Discussion: Cloaking antibodies are prevalent in patients with Burkholderia pulmonary infection and protect these strains from serum killing. Removal of cloaking antibodies via plasmapheresis, as previously described for individuals with life-threatening Pseudomonas infection, may be a useful new strategy for those with serious and life-threatening Burkholderia infection. [ABSTRACT FROM AUTHOR]

Burkholderia cepacia complex (Bcc) is a bacterial group with 'natural' multi-antimicrobial resistance. This complex has generated epidemic outbreaks across the world. In people with cystic fibrosis (CF), Bcc can cause severe lung infections that lead to accelerated lung damage, which can be complicated by necrotizing pneumonia accompanied by high fevers, leucocytosis, and bacteraemia, which commonly causes fatal outcomes. Specifically, infection by Burkholderia cenocepacia is considered an exclusion criterion for lung transplantation. The species of Bcc exhibit both genetic and phenotypic hypervariability that complicate their accurate microbiological identification. Automated methods such as MALDI-TOF can err in the determination of species. Their slow growth even in selective agars and the absence of international consensuses on the optimal conditions for their isolation make early diagnosis a difficult challenge to overcome. The absence of correlations between antibiograms and clinical results has resulted in the absence of standardized cut-off values of antimicrobial susceptibility, a fact that brings a latent risk since incorrect antibiotic therapy can induce the selection of more aggressive variants that worsen the clinical picture of the host, added to the absence of a clear therapeutic guide for the eradication of pulmonary infections by Bcc in patients with CF, resulting in frequently ineffective treatments. There is an urgent need to standardize methods and diagnostic tools that would allow an early and accurate diagnosis, as well as to perform clinical studies of the effectiveness of available antibiotics to eradicate Bcc infections, which would allow us to establish standardized therapeutic schemes for Bcc-infected patients. [ABSTRACT FROM AUTHOR]

ABSTRACT: Objectives: Burkholderia dolosa is a clinically important opportunistic pathogen in inpatients. Here we characterised an extensively drug-resistant and hypervirulent B. dolosa isolate from a patient hospitalised for stroke. Methods: Resistance to 41 antibiotics was tested with the agar disc diffusion, minimum inhibitory concentration, or broth microdilution method. The complete genome was assembled using short-reads and long-reads and the hybrid de novo assembly method. Allelic profiles obtained by multilocus sequence typing were analysed using the PubMLST database. Antibiotic-resistance and virulence genes were predicted in silico using public databases and the ‘baargin’ workflow. B. dolosa N149 phylogenetic relationships with all available B. dolosa strains and Burkholderia cepacia complex strains were analysed using the pangenome obtained with Roary. Results: B. dolosa N149 displayed extensive resistance to 31 antibiotics and intermediate resistance to 4 antibiotics. The complete genome included three circular chromosomes (6 338 630 bp in total) and one plasmid (167 591 bp). Genotypic analysis revealed various gene clusters (acr, amr, amp, emr, ade, bla and tet) associated with resistance to 35 antibiotic classes. The major intrinsic resistance mechanisms were multidrug efflux pump alterations, inactivation and reduced permeability of targeted antibiotics. Moreover, 91 virulence genes (encoding proteins involved in adherence, formation of capsule, biofilm and colony, motility, phagocytosis inhibition, secretion systems, protease secretion, transmission and quorum sensing) were identified. B. dolosa N149 was assigned to a novel sequence type (ST2237) and formed a mono-phylogenetic clade separated from other B. dolosa strains. Conclusions: This study provided insights into the antimicrobial resistance and virulence mechanisms of B. dolosa.

Background: In current literature there are only scarce data on the host inflammatory response during Burkholderia cepacia complex (Bcc) persistence. The primary objective of the present research was to carry out cross-sectional analyses of biomarkers and evaluate disease progression in cystic fibrosis (CF) patients with chronic Bcc infection and pathogen-free ones. The secondary aim was to assess prospectively overall survival of the study participants during up to 8 years of follow-up. Methods: The study included 116 paediatric patients with CF; 47 CF patients were chronically infected with Bcc, and 69 individuals were Bcc free. Plasma and sputum biomarkers (neutrophil elastase, MMP-8, MMP-9, MMP-12, IL-2, IL-4, IL-6, IL-8, IL-10, IL-18, IL-22, IL-23, IL-17, IFN-γ, TGFβ1, TNF-α) were analysed using commercially available kits. Besides, inhibitory effect of dexamethasone on proliferative response of PHA-stimulated peripheral blood lymphocytes had been assessed. Results: Bcc infected patients did not differ from Bcc free ones in demographic and clinical parameters, but demonstrated an increased rate of glucose metabolism disturbances and survival disadvantage during prolong follow-up period. Biomarkers analyses revealed elevated TNF-α and reduced IL-17F levels in sputum samples of Bcc infected patients. These patients also demonstrated improvement of peripheral blood lymphocyte sensitivity to steroid treatment and reduction in plasma pro-inflammatory (IL-17F and IL-18) and anti-inflammatory (TGFβ1 and IL-10) cytokine concentrations. Conclusions: Reduction in IL-17F levels may have several important consequences including increase in steroid sensitivity and glycemic control disturbances. Further investigations are needed to clarify the role of IL-17 cytokines in CF complication development. Low plasma TGFb1 and IL-10 levels in Bcc infected group may be a sign of subverted activity of regulatory T cells. Such immune alterations may be one of the factors contributing to the development of the cepacia syndrome. [ABSTRACT FROM AUTHOR]

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. [ABSTRACT FROM AUTHOR]

IntroductionThe Burkholderia cepacia complex encompasses a group of gram-negative opportunistic pathogens that cause chronic lung infections in people with cystic fibrosis. Distinct from other respiratory pathogens, Burkholderia causes a unique clinical disease in a subset of patients known as ‘cepacia syndrome’, fulminant pneumonia accompanied by bacteraemia and sepsis with a mortality rate of up to 75%. Due to the bacteraemia associated with this disease, the mechanisms that allow Burkholderia to resist the bactericidal effects of serum complement-depending killing are vital. Antibodies usually promote serum killing; however, we have described ‘cloaking antibodies’, specific for lipopolysaccharides that paradoxically protect serum-sensitive bacteria from complement-mediated lysis. Cloaking antibodies that protect Pseudomonas aeruginosa have been found in 24%–41% of patients with chronic lung diseases. The presence of these antibodies is also associated with worse clinical outcomes. Here, we sought to determine the relevance of cloaking antibodies in patients with Burkholderia infection.MethodsTwelve Burkholderia spp. were isolated from nine pwCF and characterised for susceptibility to healthy control serum. Patient serum was analysed for the titre of the cloaking antibody. The ability of the patient serum to prevent healthy control serum (HCS) killing of its cognate isolates was determined.ResultsWe found that several of the Burkholderia strains were shared between patients. Ten of the 12 isolates were highly susceptible to HCS killing. Four of nine (44%) patients had cloaking antibodies that protected their cognate strain from serum killing. Depleting cloaking antibodies from patient serum restored HCS killing of Burkholderia isolates.DiscussionCloaking antibodies are prevalent in patients with Burkholderia pulmonary infection and protect these strains from serum killing. Removal of cloaking antibodies via plasmapheresis, as previously described for individuals with life-threatening Pseudomonas infection, may be a useful new strategy for those with serious and life-threatening Burkholderia infection.

ABSTRACT: Objectives: Gram-negative pathogens causing respiratory infection in people with cystic fibrosis and bronchiectasis are becoming progressively more resistant to conventional antibiotics. Although cefiderocol is licenced for the treatment of infections due to Gram-negative organisms, there are limited data on the activity of cefiderocol against pathogens associated with chronic respiratory diseases. The aim of this study was to determine the susceptibility of Gram-negative pathogens from cystic fibrosis and bronchiectasis to cefiderocol and comparator antibiotics. Methods: Minimal inhibitory concentrations (MICs) of cefiderocol and 15 comparator antibiotics were determined by broth microdilution against 300 respiratory isolates: Burkholderia spp., Stenotrophomonas spp., Achromobacter spp., Ralstonia spp. and Pandoraea spp., and used to calculate the MIC of each antibiotic required to inhibit 50% (MIC50) and 90% (MIC90) of isolates. Results: The MIC50 and MIC90 of cefiderocol for all 300 isolates tested was 0.25 and 32 mg/L, with 232 (77.3%) isolates having an MIC value ≤2 mg/L. In addition, cefiderocol demonstrated excellent activity against Stenotrophomonas spp. and Achromobacter spp. isolates, with 86.7% and 87.2%, respectively, exhibiting an MIC of 2 mg/L. Tigecycline also demonstrated good activity against all isolates with an MIC50 of

AbstractBurkholderia cepacia complex (Bcc) is a bacterial group with ‘natural’ multi-antimicrobial resistance. This complex has generated epidemic outbreaks across the world. In people with cystic fibrosis (CF), Bcc can cause severe lung infections that lead to accelerated lung damage, which can be complicated by necrotizing pneumonia accompanied by high fevers, leucocytosis, and bacteraemia, which commonly causes fatal outcomes. Specifically, infection by Burkholderia cenocepacia is considered an exclusion criterion for lung transplantation. The species of Bcc exhibit both genetic and phenotypic hypervariability that complicate their accurate microbiological identification. Automated methods such as MALDI-TOF can err in the determination of species. Their slow growth even in selective agars and the absence of international consensuses on the optimal conditions for their isolation make early diagnosis a difficult challenge to overcome. The absence of correlations between antibiograms and clinical results has resulted in the absence of standardized cut-off values of antimicrobial susceptibility, a fact that brings a latent risk since incorrect antibiotic therapy can induce the selection of more aggressive variants that worsen the clinical picture of the host, added to the absence of a clear therapeutic guide for the eradication of pulmonary infections by Bcc in patients with CF, resulting in frequently ineffective treatments. There is an urgent need to standardize methods and diagnostic tools that would allow an early and accurate diagnosis, as well as to perform clinical studies of the effectiveness of available antibiotics to eradicate Bcc infections, which would allow us to establish standardized therapeutic schemes for Bcc-infected patients.

Burkholderia cepacia complex (BCC) is a Gram-negative, non-spore-forming bacterium with more than 20 opportunistic pathogenic species, most commonly found in soil and water. Due to their rapid mutation rates, these organisms are adaptable and possess high genomic plasticity. BCC can cause life-threatening infections in immunocompromised individuals, such as those with cystic fibrosis, chronic granulomatous disease, and neonates. BCC contamination is a significant concern in pharmaceutical manufacturing, frequently causing non-sterile product recalls. BCC has been found in purified water, cosmetics, household items, and even ultrasound gel used in veterinary practices. Pharmaceuticals, personal care products, and cleaning solutions have been implicated in numerous outbreaks worldwide, highlighting the risks associated with intrinsic manufacturing site contamination. Regulatory compliance, product safety, and human health protection depend on testing for BCC in pharmaceutical manufacturing. Identification challenges exist, with BCC often misidentified as other bacteria like non-lactose fermenting Escherichia coli or Pseudomonas spp., particularly in developing countries where reporting BCC in pharmaceuticals remains limited. This review comprehensively aims to address the organisms causing BCC contamination, genetic diversity, identification challenges, regulatory requirements, and mitigation strategies. Recommendations are proposed to aid pharmaceutical chemists in managing BCC-associated risks and implementing prevention strategies within manufacturing processes. [ABSTRACT FROM AUTHOR]

Small non-coding RNAs (sRNAs) are key regulators of post-transcriptional gene expression in bacteria. Hundreds of sRNAs have been found using in silico genome analysis and experimentally based approaches in bacteria of the Burkholderia cepacia complex (Bcc). However, and despite the hundreds of sRNAs identified so far, the number of functionally characterized sRNAs from these bacteria remains very limited. In this mini-review, we describe the general characteristics of sRNAs and the main mechanisms involved in their action as regulators of post-transcriptional gene expression, as well as the work done so far in the identification and characterization of sRNAs from Bcc. The number of functionally characterized sRNAs from Bcc is expected to increase and to add new knowledge on the biology of these bacteria, leading to novel therapeutic approaches to tackle the infections caused by these opportunistic pathogens, particularly severe among cystic fibrosis patients. Key points: •Hundreds of sRNAs have been identified in Burkholderia cepacia complex bacteria (Bcc). •A few sRNAs have been functionally characterized in Bcc. •Functionally characterized Bcc sRNAs play major roles in metabolism, biofilm formation, and virulence. [ABSTRACT FROM AUTHOR]

Burkholderia are a group of Gram-negative bacteria that can cause a variety of diseases in at-risk populations. B. pseudomallei and B. mallei, the etiological agents of melioidosis and glanders, respectively, are the two clinically relevant members of the B. pseudomallei complex (Bpc). The development of vaccines against Bpc species has been accelerated in recent years, resulting in numerous promising subunits and glycoconjugate vaccines incorporating a variety of antigens. However, a second group of pathogenic Burkholderia species exists known as the Burkholderia cepacia complex (Bcc), a group of opportunistic bacteria which tend to affect individuals with weakened immunity or cystic fibrosis. To date, there have been few attempts to develop vaccines to Bcc species. Therefore, the primary goal of this review is to provide a broad overview of the various subunit antigens that have been tested in Bpc species, their protective efficacy, study limitations, and known or suspected mechanisms of protection. Then, we assess the reviewed Bpc antigens for their amino acid sequence conservation to homologous proteins found in Bcc species. We propose that protective Bpc antigens with a high degree of Bpc-to-Bcc sequence conservation could serve as components of a pan-Burkholderia vaccine capable of protecting against both disease-causing groups. [ABSTRACT FROM AUTHOR]

Introduction: Burkholderia cepacia complex (BCC) is ubiquitous in nature, present in water, soil, and plants. BCC is comprised of Gram-negative non-lactose-fermenting bacteria. Gram negative, non lactose fermenting Burkholderia cepacia complex has emerged as an opportunistic nosocomial pathogen causing significant morbidity and mortality in hospitalized patients owing to its high antibiotic resistance. This study was aimed to determine prevalence of Burkholderia cepacia complex and to evaluate sensitivity pattern of Burkholderia cepacia complex in blood stream infections in Dhiraj Hospital, Gujarat which is a tertiary care hospital and teaching institute. Materials and Methods: The present study was conducted in the Department of Microbiology for a period from January 2022 to December 2022 of Dhiraj General Hospital, SBKS MI & RC, Waghodia, Gujarat. All samples were received in central laboratory and blood cultures were processed in BD BACTEC FX40. The positive culture bottles were sub cultured on Mac Conkey agar, Blood agar and Nutrient agar and were incubated for 24 hours at 37°C. The data was collected and analyzed statistically. Results: During the study period 31 positive samples for BCC were isolated from a total of 612 culture samples, thus the prevalence rate was 5.06% in our setup. BCC was found majorly in ICUs (65%) and in wards (35%). The isolates showed maximum sensitivity to Co-Trimoxazole (83.87%), followed by Ceftazidime (58.06%), Meropenem (54.83%) and Minocycline (51.61%). Conclusion: From various studies and our study we could conclude that there were variations in the results of drug sensitivity. So, there is need to properly isolate and do antibiotic sensitivity testing for better patient management. Prompt diagnosis is essential step to reduce mortality and establish infection control practices. [ABSTRACT FROM AUTHOR]

BackgroundIn current literature there are only scarce data on the host inflammatory response during Burkholderia cepacia complex (Bcc) persistence. The primary objective of the present research was to carry out cross-sectional analyses of biomarkers and evaluate disease progression in cystic fibrosis (CF) patients with chronic Bcc infection and pathogen-free ones. The secondary aim was to assess prospectively overall survival of the study participants during up to 8 years of follow-up.MethodsThe study included 116 paediatric patients with CF; 47 CF patients were chronically infected with Bcc, and 69 individuals were Bcc free. Plasma and sputum biomarkers (neutrophil elastase, MMP-8, MMP-9, MMP-12, IL-2, IL-4, IL-6, IL-8, IL-10, IL-18, IL-22, IL-23, IL-17, IFN-γ, TGFβ1, TNF-α) were analysed using commercially available kits. Besides, inhibitory effect of dexamethasone on proliferative response of PHA-stimulated peripheral blood lymphocytes had been assessed.ResultsBcc infected patients did not differ from Bcc free ones in demographic and clinical parameters, but demonstrated an increased rate of glucose metabolism disturbances and survival disadvantage during prolong follow-up period. Biomarkers analyses revealed elevated TNF-α and reduced IL-17F levels in sputum samples of Bcc infected patients. These patients also demonstrated improvement of peripheral blood lymphocyte sensitivity to steroid treatment and reduction in plasma pro-inflammatory (IL-17F and IL-18) and anti-inflammatory (TGFβ1 and IL-10) cytokine concentrations.ConclusionsReduction in IL-17F levels may have several important consequences including increase in steroid sensitivity and glycemic control disturbances. Further investigations are needed to clarify the role of IL-17 cytokines in CF complication development. Low plasma TGFβ1 and IL-10 levels in Bcc infected group may be a sign of subverted activity of regulatory T cells. Such immune alterations may be one of the factors contributing to the development of the cepacia syndrome.

Summary: Background: Wound dressing is intended to provide a physical barrier from microorganisms. Spray dressing is convenient and can be applied to wounds of various contours. In July 2020, a cluster of four Burkholderia cepacia complex (BCC) exit site infections was identified among peritoneal dialysis patients in a regional hospital in Hong Kong. In response, our hospital infection control team conducted an epidemiologic investigation. Methods: We conducted a retrospective cohort study of peritoneal dialysis patients with culture-confirmed BCC exit site infections from January 2011 to July 2020. Outbreak investigations, including case finding, molecular typing and post-outbreak surveillance, were performed. Discussion: A substantial increase in BCC exit site infections has been observed since 2013, rising from 0.23 in 2012 to 1.09 episodes per 100 patient-year in 2015, with the number of cases in the first half of 2020 already surpassing the total from 2019. The potential source had been traced to a spray dressing introduced to exit site care in December 2012. Burkholderia cepacia complex was isolated from both the unopened and in-use sprays from the same lot. Multilocus sequence typing analysis confirmed their genetic relatedness. The spray dressing was subsequently removed from exit site care. Post-outbreak surveillance over two years showed a marked and sustained decrease in BCC exit site infection. Conclusion: Water-based spray dressing can be a source of BCC causing wound infections. The use of contaminated spray dressing, especially in chronic wounds with proximity to indwelling catheters, may pose an inherent risk to patients.

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. 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. 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. 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. [ABSTRACT FROM AUTHOR]

Introduction: The Burkholderia cepacia complex (BCC) encompasses a group of at least 22 genetically distinct gram-negatives bacterial species ubiquitous in nature. Recognised as a group of genetically and phenotypically flexible species, the BCC inhabits diverse ecological niches causing both plant and human diseases. Comparative genomic analysis provides an in depth understanding into the population biology, phylogenetic relationship, and genomic architecture of species. Methods: Here, we genomically characterise Burkholderia anthina isolated from patients with chronic lung infections, an understudied pathogen within the Burkholderia cepacia complex. Results: We demonstrate that B. anthina is polyphyletic and constitutes two distinct evolutionary lineages. Core- and pan-genome analyses demonstrated substantial metabolic diversity, with B. anthina Clade I enriched in genes associated with microbial metabolism in diverse environments, including degradation of aromatic compounds and metabolism of xenobiotics, while B. anthina Clade II demonstrated an enhanced capability for siderophore biosynthesis. Discussion: Based on our phylogenetic and comparative genomic analyses, we suggest stratifying B. anthina to recognise a distinct species harbouring increased potential for iron metabolism via siderophore synthesis, for which we propose the name Burkholderia anthinoferum (sp. nov.). [ABSTRACT FROM AUTHOR]

Burkholderia cepacia complex (BCC) is a group of gram-negative bacteria composed of at least 20 different species that cause diseases in plants, animals as well as humans (cystic fibrosis and airway infection). Here, we analyzed the proteomic data of 47 BCC strains by classifying them in three groups. Phylogenetic analyses were performed followed by individual core region identification for each group. Comparative analysis of the three individual core protein fractions resulted in 1766 ortholog/proteins. Non-human homologous proteins from the core region gave 1680 proteins. Essential protein analyses reduced the target list to 37 proteins, which were further compared to a closely related out-group, Burkholderia gladioli ATCC 10,248 strain, resulting in 21 proteins. 3D structure modeling, validation, and druggability step gave six targets that were subjected to further target prioritization parameters which ultimately resulted in two BCC targets. A library of 12,000 ZINC drug-like compounds was screened, where only the top hits were selected for docking orientations. These included ZINC01405842 (against Chorismate synthase aroC) and ZINC06055530 (against Bifunctional N-acetylglucosamine-1-phosphate uridyltransferase/Glucosamine-1-phosphate acetyltransferase glmU). Finally, dynamics simulation (200 ns) was performed for each ligand–receptor complex, followed by ADMET profiling. Of these targets, details of their applicability as drug targets have not yet been elucidated experimentally, hence making our predictions novel and it is suggested that further wet-lab experimentations should be conducted to test the identified BCC targets and ZINC scaffolds to inhibit them. [ABSTRACT FROM AUTHOR]

The Burkholderia cepacia complex (Bcc) causes life-threatening respiratory tract infections in persons with cystic fibrosis (CF). In CF patients, end-stage pulmonary disease often requires lung transplantation, and pre-transplant colonization with antibiotic-resistant Burkholderia is predictive of poor post-transplant outcomes. To address this issue, phage therapy has been proposed as a treatment for these infections. However, the majority of characterized Bcc phages are temperate and are therefore difficult to use as therapeutics, and the few obligately lytic phages that have been isolated have limited host ranges. To overcome these limitations, we have produced a virulent, broad-host range derivative of the temperate Burkholderia cenocepacia phage Milagro. Phage Milagro is a 39.1-kb temperate myophage related to phage KL3 and the paradigm coliphage P2. This phage showed a phenotype of spontaneous autoplaquing on lawns of Milagro lysogens, and these autoplaques were found to be produced by virulent mutants of the parental phage Milagro. Mutations associated with virulence were identified as single base changes, insertions or deletions in the phage lysogeny control region that define potential operator sites required for lysogen maintenance. To improve phage host range, the C-terminal domain of the Milagro tail fiber was replaced with the receptor-binding domain of the broad-host range tailocin (high molecular weight bacteriocin) BceTMilo. A spontaneous virulent mutant of this engineered phage, designated Milagro vir gp20:Milo, exhibited an expanded host range over the parental phage and is able to infect multiple Bcc species including B. cenocepacia, Burkholderia multivorans, Burkholderia gladioli, Burkholderia dolosa, and Burkholderia vietnamensis. [ABSTRACT FROM AUTHOR]

ABSTRACTBurkholderia cepacia complex (BCC) and Stenotrophomonas maltophilia are nosocomial pathogens that cause various infections and exhibit high resistance to multiple antimicrobial agents. In this study, we aimed to develop a duplex droplet digital PCR (ddPCR) assay for detecting BCC and S. maltophilia in bloodstream infections. We optimized the experimental conditions by setting the annealing temperature to 51°C and determining the optimal concentrations of primers and probes, as well as the thermal cycle numbers. The feasibility of the duplex ddPCR reaction system with the optimal conditions was established and verified through parallel reactions with reference strains of BCC and S. maltophilia. The specificity of the assay, tested with 33 reference strains, was found to be 100%. The duplex ddPCR assay demonstrated good repeatability and could detect as low as 5.35 copies/reaction of BCC and 7.67 copies/reaction of S. maltophilia. This level of sensitivity was consistent in the simulated blood and blood bottle samples. We compared nucleic acid extraction methods and found that the Chelex-100 boiling method and kit extraction method exhibited similar detection sensitivity, suggesting the potential application of the Chelex-100 boiling method in the ddPCR assay. In the clinical samples, the duplex ddPCR assay accurately detected BCC and S. maltophilia in 58 cases. In conclusion, our study successfully developed a duplex ddPCR assay that provides accurate and convenient detection of BCC and S. maltophilia in bloodstream infections.IMPORTANCEBurkholderia cepacia complex (BCC) and Stenotrophomonas maltophilia are implicated in a wide range of infections, including bloodstream infections (BSIs), pneumonia, and meningitis, and often exhibit high intrinsic resistance to multiple antimicrobial agents, limiting therapeutic options. The gold standard for diagnosing bloodstream infections remains blood culture. However, current blood culture detection and positivity rates do not meet the “rapid diagnosis” required for the diagnosis and treatment of critically ill patients with BSIs. The digital droplet PCR (ddPCR) method is a potentially more powerful tool in the diagnosis of BSIs compared to other molecular methods due to its greater sensitivity, specificity, accuracy, and reproducibility. In this study, a duplex ddPCR assay for the detection of BCC and S. maltophilia in BSIs was developed.

Scientific relevance. Medicinal products formulated as aerosols and sprays are increasingly used in clinical practice, which makes the control of their quality, including microbiological testing, a highly topical issue. The current regulatory standards for microbiological testing of medicines provide little information on the quality control of metereddose aerosols. Proper microbiological sampling of these medicinal products can be difficult because of their primary packaging. The specialised analytical procedures set forth in international standards require verification and standardisation before use. Medicinal products in the form of sprays, despite being free from the disadvantages of aerosols, are more susceptible to the risk of microbial contamination.Aim. The study aimed to describe specific aspects of sampling, to analyse the results of microbiological testing of aerosols and sprays, and to study the spectrum of microbial contaminants in these dosage forms.Materials and methods. The authors retrospectively analysed the microbiological quality and sterility data for 181 batches of sprays, aerosols, and other inhalation dosage forms. The data were obtained at the Scientific Centre for Expert Evaluation of Medicinal Products of the Ministry of Health of Russia in 2020–2022. The Microbiology Laboratory tested the dosage forms according to the specifications provided by the manufacturers. The analysts used well-established testing procedures outlined in the current pharmacopoeias of the Russian Federation and the Eurasian Economic Union.Results. The microbial counts exceeded the acceptable limits in 2.8% of the batches tested. The authors identified the microbial species that contaminated the medicinal products found to be non-compliant with regulatory requirements. Most of the non-compliant sprays that contained benzalkonium chloride as an antibacterial preservative were contaminated with Burkholderia cepacia complex species.Conclusions. The authors consider it relevant to conduct research aiming at using the findings on potential contaminants to improve microbiological testing procedures for aerosols and sprays.

Ya-Chun Liao,1 Yao-Ting Huang,2,* Chien-Hao Tseng,1 Chia-Wei Liu,1 Po-Yu Liu1,3,4,* 1Division of Infectious Diseases, Department of Internal Medicine, Taichung Veterans General Hospital, Taichung, Taiwan; 2Department of Computer Science and Information Engineering, National Chung Cheng University, Chiayi, Taiwan; 3Department of Post-Baccalaureate Medicine, National Chung Hsing University, Taichung, Taiwan; 4Genome Center for Infectious Diseases, Taichung Veterans General Hospital, Taichung, Taiwan*These authors contributed equally to this workCorrespondence: Po-Yu Liu, Division of Infectious Diseases, Department of Internal Medicine, Taichung Veterans General Hospital, No. 1650, Sec. 4, Taiwan Blvd., Xitun District, Taichung, Taiwan, Tel +886-4-2359-2525, Fax +886-4-2359-5046, Email pyliu@vghtc.gov.twPurpose: Burkholderia cepacia complex (Bcc) is a known significant opportunistic pathogen causing morbidity and mortality, particularly in those with cystic fibrosis, chronic granulomatous disease, or immunocompromising host. Mortality of Bcc bloodstream infections among non-cystic fibrosis patients remained high. The antibiotic treatment for Bcc infection is quite challenging due to its intrinsic resistance to most antibiotics, and the resistance to carbapenems was the biggest concern among them. We aimed to realize the mechanism of carbapenem resistance in Bcc.Patients and Methods: Ten strains of Bcc were identified by the MALDI-TOF MS, and the drug susceptibility test was using VITEK 2 system. The Burkholderia cepacia complex genomes were sequenced via Nanopore GridIon. We also downloaded another ninety-five strains of Bcc from the National Center for Biotechnology Information database to evaluate the divergence between carbapenem-resistance and carbapenem-sensitive strains.Results: The genetic organization between carbapenem-sensitive and carbapenem-resistant strains of Bcc showed no difference. However, in the carbapenem-sensitive strain, E151V substitution in PenR was detected. In addition, a novel specific OXA family subgroup, blaOXA-1043 in Burkholderia cenocepacia was discovered.Conclusion: The E151V substitution in PenR may be associated with carbapenem-sensitive in Bcc. Moreover, the V151E mutation in PenR may be related to the activation of PenB, leading to Bcc resistance to carbapenems. Besides, a novel OXA family subgroup, blaOXA-1043, was found in Burkholderia cenocepacia, which differs from the previous OXA family.Keywords: Burkholderia cepacia complex, Burkholderia cenocepacia, carbapenem-resistant, whole-genome sequencing

Burkholderia cepacia complex (BCC) has been recognized as a serious cause of pneumonia in patients with cystic fibrosis. BCC infection has also been reported in non-cystic fibrosis patients. Notably, the mortality rate of bacterial pneumonia caused by BCC is high. Nonetheless, therapeutic management of BCC infection remains to be established. Recent reports have indicated successful treatment of BCC pneumonia with combination antibiotic therapy. However, no reports have detailed the efficacy of combination antibiotic therapy for both initial and recurrent BCC pneumonia management. We herein describe a rare case of BCC pneumonia in a non-cystic fibrosis patient that was successfully treated with a combination of intravenous, inhalational and oral antibiotics. Furthermore, antibiotic therapy including inhaled tobramycin has been continued after discharge from hospital, and no side effects or recurrence of bacterial pneumonia has been observed, although BCC has been detected in sputum. The findings of the present case suggest that combination antibiotic therapy including inhaled tobramycin may be effective for recurrent bacterial pneumonia caused by BCC. In the management of BCC infection, early diagnosis should be made based on sputum culture results, and combination antibiotic therapy should be initiated promptly.

There are limited case reports on individuals infected with Burkholderia cepacia who do not have typical risk factors, particularly pregnant women with beta-thalassemia. A 34-year-old pregnant female with beta-thalassemia trait and hypertension was admitted to the hospital. The patient was diagnosed with eclampsia and underwent a cesarean section. After two days following the surgery, the patient experienced hospitality-acquired pneumonia. B.cepacia was isolated from blood cultures, and antibiotic susceptibility testing indicated sensitivity to trimethoprim/sulfamethoxazole and levofloxacin. The patient responded to antibiotic treatment. These findings highlight the importance of prompt diagnosis and appropriate treatment in managing B.cepacia infections in pregnant beta-thalassemia patients.

IntroductionThe Burkholderia cepacia complex (BCC) encompasses a group of at least 22 genetically distinct gram-negatives bacterial species ubiquitous in nature. Recognised as a group of genetically and phenotypically flexible species, the BCC inhabits diverse ecological niches causing both plant and human diseases. Comparative genomic analysis provides an in depth understanding into the population biology, phylogenetic relationship, and genomic architecture of species.MethodsHere, we genomically characterise Burkholderia anthina isolated from patients with chronic lung infections, an understudied pathogen within the Burkholderia cepacia complex.ResultsWe demonstrate that B. anthina is polyphyletic and constitutes two distinct evolutionary lineages. Core- and pan-genome analyses demonstrated substantial metabolic diversity, with B. anthina Clade I enriched in genes associated with microbial metabolism in diverse environments, including degradation of aromatic compounds and metabolism of xenobiotics, while B. anthina Clade II demonstrated an enhanced capability for siderophore biosynthesis.DiscussionBased on our phylogenetic and comparative genomic analyses, we suggest stratifying B. anthina to recognise a distinct species harbouring increased potential for iron metabolism via siderophore synthesis, for which we propose the name Burkholderia anthinoferum (sp. nov.).

Objective: To mine specific proteins and their protein-coding genes as suitable molecular biomarkers for the Burkholderia cepacia Complex (BCC) bacteria detection based on mega analysis of microbial proteomic and genomic data comparisons and to develop a real-time recombinase polymerase amplification (rt-RPA) assay for rapid isothermal screening for pharmaceutical and personal care products. Methods: We constructed an automatic screening framework based on Python to compare the microbial proteomes of 78 BCC strains and 263 non-BCC strains to identify BCC-specific protein sequences. In addition, the specific protein-coding gene and its core DNA sequence were validated in silico with a self-built genome database containing 158 thousand bacteria. The appropriate methodology for BCC detection using rt-RPA was evaluated by 58 strains in pure culture and 33 batches of artificially contaminated pharmaceutical and personal care products. Results: We identified the protein SecY and its protein-coding gene secY through the automatic comparison framework. The virtual evaluation of the conserved region of the secY gene showed more than 99.8% specificity from the genome database, and it can distinguish all known BCC species from other bacteria by phylogenetic analysis. Furthermore, the detection limit of the rt-RPA assay targeting the secY gene was 5.6 × 102 CFU of BCC bacteria in pure culture or 1.2 pg of BCC bacteria genomic DNA within 30 min. It was validated to detect <1 CFU/portion of BCC bacteria from artificially contaminated samples after a pre-enrichment process. The relative trueness and sensitivity of the rt-RPA assay were 100% in practice compared to the reference methods. Conclusion: The automatic comparison framework for molecular biomarker mining is straightforward, universal, applicable, and efficient. Based on recognizing the BCC-specific protein SecY and its gene, we successfully established the rt-RPA assay for rapid detection in pharmaceutical and personal care products. [ABSTRACT FROM AUTHOR]

Burkholderia are a group of Gram-negative bacteria that can cause a variety of diseases in at-risk populations. B. pseudomallei and B. mallei, the etiological agents of melioidosis and glanders, respectively, are the two clinically relevant members of the B. pseudomallei complex (Bpc). The development of vaccines against Bpc species has been accelerated in recent years, resulting in numerous promising subunits and glycoconjugate vaccines incorporating a variety of antigens. However, a second group of pathogenic Burkholderia species exists known as the Burkholderia cepacia complex (Bcc), a group of opportunistic bacteria which tend to affect individuals with weakened immunity or cystic fibrosis. To date, there have been few attempts to develop vaccines to Bcc species. Therefore, the primary goal of this review is to provide a broad overview of the various subunit antigens that have been tested in Bpc species, their protective efficacy, study limitations, and known or suspected mechanisms of protection. Then, we assess the reviewed Bpc antigens for their amino acid sequence conservation to homologous proteins found in Bcc species. We propose that protective Bpc antigens with a high degree of Bpc-to-Bcc sequence conservation could serve as components of a pan-Burkholderia vaccine capable of protecting against both disease-causing groups.

The study aimed to screen prospective molecular targets of BCC and potential natural lead candidates as effective binders by computational modeling, molecular docking, and dynamic (MD) simulation studies. Based on the virulent functions, tRNA 5‐methylaminomethyl‐2‐thiouridine biosynthesis bifunctional protein (mnmC) and pyrimidine/purine nucleoside phosphorylase (ppnP) were selected as the prospective molecular targets. In the absence of experimental data, the three‐dimensional (3D) structures of these targets were computationally predicted. After a thorough literature survey and database search, the drug‐likeness, and pharmacokinetic properties of 70 natural molecules were computationally predicted and the effectual binding of the best lead molecules against both the targets was predicted by molecular docking. The stabilities of the best‐docked complexes were validated by MD simulation and the binding energy calculations were carried out by MM‐GBSA approaches. The present study revealed that the hypothetical models of mnmC and ppnP showed stereochemical accuracy. The study also showed that among 70 natural compounds subjected to computational screening, Honokiol (3′,5‐Di(prop‐2‐en‐1‐yl) [1,1′‐biphenyl]‐2,4′‐diol) present in Magnolia showed ideal drug‐likeness, pharmacokinetic features and showed effectual binding with mnmC and ppnP (binding energies −7.3 kcal/mol and −6.6 kcal/mol, respectively). The MD simulation and GBSA calculation studies showed that the ligand‐protein complexes stabilized throughout tMD simulation. The present study suggests that Honokiol can be used as a potential lead molecule against mnmC and ppnP targets of BCC and this study provides insight into further experimental validation for alternative lead development against drug resistant BCC. [ABSTRACT FROM AUTHOR]

The Burkholderia cepacia complex comprises environmental and clinical Gram-negative bacteria that infect particularly debilitated people, such as those with cystic fibrosis. Their high level of antibiotic resistance makes empirical treatments often ineffective, increasing the risk of worst outcomes and the diffusion of multi-drug resistance. However, the discovery of new antibiotics is not trivial, so an alternative can be the use of vaccination. Here, the reverse vaccinology approach has been used to identify antigen candidates, obtaining a short-list of 24 proteins. The localization and different aspects of virulence were investigated for three of them—BCAL1524, BCAM0949, and BCAS0335. The three antigens were localized in the outer membrane vesicles confirming that they are surface exposed. We showed that BCAL1524, a collagen-like protein, promotes bacteria auto-aggregation and plays an important role in virulence, in the Galleria mellonella model. BCAM0949, an extracellular lipase, mediates piperacillin resistance, biofilm formation in Luria Bertani and artificial sputum medium, rhamnolipid production, and swimming motility; its predicted lipolytic activity was also experimentally confirmed. BCAS0335, a trimeric adhesin, promotes minocycline resistance, biofilm organization in LB, and virulence in G. mellonella. Their important role in virulence necessitates further investigations to shed light on the usefulness of these proteins as antigen candidates. [ABSTRACT FROM AUTHOR]

Both sterile and non-sterile pharmaceutical products, which include antiseptics, have been recalled due to Burkholderia cepacia complex (BCC) contamination. Therefore, minimizing the frequency of outbreaks may be conducive to the development of a quick and sensitive approach that can distinguish between live and dead loads of BCC. We have assessed an exo probe-based recombinase polymerase amplification (RPA) with 10 µM propidium monoazide (PMAxx) for selective detection of live/dead BCC cells in various concentrations of antiseptics (i.e., chlorhexidine gluconate (CHX) and benzalkonium chloride (BZK) solutions) after 24 h. The optimized assay conducted using a set of primer–probes targeting gbpT was performed at 40 °C for 20 min and shows a detection limit of 10 pg/µL of genomic DNA from B. cenocepacia J2315, equivalent to 104 colony-forming units (CFU/mL). The specificity of a newly designed primer and probe was 80% (20 negatives out of 25). The readings for total cells (i.e., without PMAxx) from 200 µg/mL CHX using PMAxx-RPA exo assay was 310 relative fluorescence units (RFU), compared to 129 RFU with PMAxx (i.e., live cells). Furthermore, in 50–500 µg/mL BZK-treated cells, a difference in the detection rate was observed between the PMAxx-RPA exo assay in live cells (130.4–459.3 RFU) and total cells (207.82–684.5 RFU). This study shows that the PMAxx-RPA exo assay appears to be a valid tool for the simple, rapid and presumptive detection of live BCC cells in antiseptics, thereby ensuring the quality and safety of pharmaceutical products. [ABSTRACT FROM AUTHOR]

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

A descriptive retrospective continuous epidemiological study of cases of bacterial isolation in pediatric patients (from 1 to 15 years of age) was performed in the regional center of cystic fibrosis, GAUZ KOKB named after S.V. Belyaev. A total of 64 case histories of an inpatient with a diagnosis of cystic fibrosis and the results of microbiological studies over a two-year period were studied. Patients with this nosology are predisposed to the colonization of the respiratory tract by various microorganisms, which aggravates the course of the disease. The system of anti-epidemic, preventive measures in the hospital allows you to avoid infection of patients during their stay.

Introduction Burkholderia cepacia complex (BCC) is an emerging pathogen causing nosocomial bloodstream infections (BSIs), and its treatment is challenging due to its multidrug resistance. In India, there is a dearth of data on BSIs caused by BCC, therefore, an updated study is required to know the clinical and microbiological profile of these patients. We aimed to study the clinical epidemiology and antibiotic susceptibility pattern of BCC isolated from blood samples in our hospital. Materials and Methods This observational study was conducted from January 2019 to December 2020 at a tertiary care center in northern India. All the blood cultures were done on an automated blood culture system. All BCC isolates of BSI were identified depending on their morphological properties and biochemical reactions, and underwent the matrix-assisted laser desorption ionization time-of-flight mass spectrometry system to confirm diagnosis. Antibiotic susceptibility testing was done as per Clinical Laboratory and Standards Institute guidelines. Results BCC was isolated from 30 BSI patients over a 2-year period. Sixty-six percent (20/30) of patients had cancer and a majority of them were undergoing chemotherapy. The most common predisposing factors were the use of steroids, immunosuppressive drugs, and chemotherapy (93.3%), central lines (83.3%), use of higher antibiotics (60%), and diabetes mellitus type 2 (60%). The most common species isolated were B. cepacia (64%) and B. cenocepacia (30%). Isolates showed highest sensitivity to minocycline (100%), ceftazidime (73.3%), and meropenem (70%) and the least to ticarcillin–clavulanate. Conclusion BCC is an emerging pathogen causing BSIs, especially in malignancy patients. Minocycline can be a good choice for these bacteria.

Cystic fibrosis is an autosomal recessive disease characterized by involvement of all exocrine glands, vital organs and systems. CFTR protein dysfunction leads to chronic infection and subsequent uncontrolled inflammation. Airway infections are associated with a progressive decline in lung function and eventually with respiratory failure, which is the leading cause of death in cystic fibrosis. That's why monitoring of microbiota spectrum in cystic fibrosis patients in some hospitals and research of sensitiveness to antibacterials of prevailing isolated isolates are urgent. The aim of the study – to study respiratory tract microbiota of cystic fibrosis patients of the pulmonology department of Kuzbass Children Clinical Hospital named after prof. Y.E. Malakhovsky (KCCH). Materials and methods. A total of 324 samples from cystic fibrosis patients from 2018 to 2021 were included in the analysis, from which 819 different microorganisms were isolated. Microbiological examination of sputum of cystic fibrosis patients was performed in the bacteriological laboratory of KCCH according to the clinical guidelines «Cystic fibrosis (cystic fibrosis): microbiological diagnosis of chronic respiratory infection». Results. Our study identified the most significant strains of pathogenic flora in children with cystic fibrosis in the pulmonology department of KCCH for the period 2018-2021 – Burkholderia cepacia complex (18.2 %), Staphylococcus aureus (9.5 %) and Pseudomonas aeruginosa (7.9 %). We obtained data on the age dynamics of the microbiota of these patients, indicating an increase in the frequency of Burkholderia cepacia complex and Staphylococcus aureus cultures in adolescence, but a decrease in Pseudomonas aeruginosa. The frequency of bacterial association reaches 73 % and is highest in Burkholderia cepacia complex (57 %).

The Burkholderia cepacia complex (Bcc) initially emerged as an important opportunistic pathogen in patients with predisposing lung disease. Bcc infections outside the respiratory tract are less common, although their incidence has been increasing particularly in immunocompromised patients. We herein describe the case of a healthy young woman who started experiencing low back pain 2 weeks after an uncomplicated cesarean section. She was found to have vertebral osteomyelitis at T12-L1. CT guided biopsy was performed, and cultures grew Bcc. She was treated with 3 weeks of meropenem and 5 weeks of oral trimethoprim-sulfamethoxazole with good response. No surgical intervention was warranted. We also performed a review of the literature on other existing reports. To the best of our knowledge, this is the first case of Bcc vertebral osteomyelitis in an immunocompetent patient following an obstetric procedure.

ABSTRACT Antimicrobial resistance is a danger to global public health and threatens many aspects of modern medicine. Bacterial species such as those of the Burkholderia cepacia complex (Bcc) cause life-threatening respiratory infections and are highly resistant to antibiotics. One promising alternative being explored to combat Bcc infections is phage therapy (PT): the use of phages to treat bacterial infections. Unfortunately, the utility of PT against many pathogenic species is limited by its prevailing paradigm: that only obligately lytic phages should be used therapeutically. It is thought that ‘lysogenic’ phages do not lyse all bacteria and can transfer antimicrobial resistance or virulence factors to their hosts. We argue that the tendency of a lysogenization-capable (LC) phage to form stable lysogens is not predicated exclusively on its ability to do so, and that the therapeutic suitability of a phage must be evaluated on a case-by-case basis. Concordantly, we developed several novel metrics—Efficiency of Phage Activity, Growth Reduction Coefficient, and Stable Lysogenization Frequency—and used them to evaluate eight Bcc-specific phages. Although these parameters vary considerably among Bcc phages, a strong inverse correlation (R2 = 0.67; P < 0.0001) exists between lysogen formation and antibacterial activity, indicating that certain LC phages with low frequency of stable lysogenization may be therapeutically efficacious. Moreover, we show that many LC Bcc phages interact synergistically with other phages in the first reported instance of mathematically defined polyphage synergy, and that these interactions result in the eradication of in vitro bacterial growth. Together, these findings reveal a novel therapeutic role for LC phages and challenge the current paradigm of PT. IMPORTANCE The spread of antimicrobial resistance is an imminent threat to public health around the world. Particularly concerning are species of the Burkholderia cepacia complex (Bcc), which cause life-threatening respiratory infections and are notoriously resistant to antibiotics. Phage therapy is a promising alternative being explored to combat Bcc infections and antimicrobial resistance in general, but its utility against many pathogenic species, including the Bcc, is restricted by the currently prevailing paradigm of exclusively using rare obligately lytic phages due to the perception that ‘lysogenic’ phages are therapeutically unsuitable. Our findings show that many lysogenization-capable phages exhibit powerful in vitro antibacterial activity both alone and through mathematically defined synergistic interactions with other phages, demonstrating a novel therapeutic role for LC phages and therefore challenging the currently prevailing paradigm of PT.

ABSTRACT The Burkholderia cepacia complex is a group of opportunistic pathogens that cause both severe acute and chronic respiratory infections. Due to their large genomes containing multiple intrinsic and acquired antimicrobial resistance mechanisms, treatment is often difficult and prolonged. One alternative to traditional antibiotics for treatment of bacterial infections is bacteriophages. Therefore, the characterization of bacteriophages infective for the Burkholderia cepacia complex is critical to determine their suitability for any future use. Here, we describe the isolation and characterization of novel phage, CSP3, infective against a clinical isolate of Burkholderia contaminans. CSP3 is a new member of the Lessievirus genus that targets various Burkholderia cepacia complex organisms. Single nucleotide polymorphism (SNP) analysis of CSP3-resistant B. contaminans showed that mutations to the O-antigen ligase gene, waaL, consequently inhibited CSP3 infection. This mutant phenotype is predicted to result in the loss of cell surface O-antigen, contrary to a related phage that requires the inner core of the lipopolysaccharide for infection. Additionally, liquid infection assays showed that CSP3 provides suppression of B. contaminans growth for up to 14 h. Despite the inclusion of genes that are typical of the phage lysogenic life cycle, we saw no evidence of CSP3’s ability to lysogenize. Continuation of phage isolation and characterization is crucial in developing large and diverse phage banks for global usage in cases of antibiotic-resistant bacterial infections. IMPORTANCE Amid the global antibiotic resistance crisis, novel antimicrobials are needed to treat problematic bacterial infections, including those from the Burkholderia cepacia complex. One such alternative is the use of bacteriophages; however, a lot is still unknown about their biology. Bacteriophage characterization studies are of high importance for building phage banks, as future work in developing treatments such as phage cocktails should require well-characterized phages. Here, we report the isolation and characterization of a novel Burkholderia contaminans phage that requires the O-antigen for infection, a distinct phenotype seen among other related phages. Our findings presented in this article expand on the ever-evolving phage biology field, uncovering unique phage-host relationships and mechanisms of infection.

Burkholderia cenocepacia TAtl-371 was isolated from the rhizosphere of a tomato plant growing in Atlatlahucan, Morelos, Mexico. This strain exhibited a broad antimicrobial spectrum against bacteria, yeast, and fungi. Here, we report and describe the improved, high-quality permanent draft genome of B. cenocepacia TAtl-371, which was sequenced using a combination of PacBio RS and PacBio RS II sequencing methods. The 7,496,106 bp genome of the TAtl-371 strain is arranged in three scaffolds, contains 6722 protein-coding genes, and 99 RNA only-encoding genes. Genome analysis revealed genes related to biosynthesis of antimicrobials such as non-ribosomal peptides, siderophores, chitinases, and bacteriocins. Moreover, analysis of bacterial growth on different carbon and nitrogen sources shows that the strain retains its antimicrobial ability.

Infectious complications in the respiratory tract caused by microorganisms from the Burkholderia cepacia complex are the main cause of death among patients with cystic fibrosis. Natural and acquired resistance mechanisms allow Burkholderia cepacia complex pathogens to adapt to the conditions of regular antibiotic therapy, which necessitates the use of antibacterial drugs with an alternative mechanism of action. Studies on the importance of iron as an essential factor in the metabolism of bacteria and methods of its acquisition from the environment contributed to the development of a new antibiotic from a number of cephalosporins – cefiderocol. In the structure of cefiderocol, a fragment is formed that imitates siderophores – chelating molecules that ensure the transport of iron ions into the internal environment of the microorganism. A unique mechanism, described in the scientific literature as a “Trojan horse”, allows antibiotic molecules conjugated with siderophores to effectively penetrate into the bacterial cell, exerting a bactericidal effect. Thus, cefiderocol can be used to treat infectious complications in the lungs of patients with cystic fibrosis caused by bacteria from the Burkholderia cepacia complex, including multidrug-resistant strains. In addition, the spectrum of activity of cefiderocol allows the use of this antibiotic in the treatment of infections caused by nosocomial gram-negative bacteria such as Enterobacterales, Acinetobacter, Pseudomonas and Stenotrophomonas.

Background: The Burkholderia cepacia complex (Bcc) is an opportunistic pathogen in humans and animals. Deep pyoderma caused by these bacteria in dogs has been previously reported. This case series aims to describe contrasting treatment responses in Bcc-related deep pyoderma in two dogs, a male and a female. Case Description: Both patients had a history of immune-mediated polyarthritis managed with oral ciclosporin and prednisolone. Their skin lesions were multifocal, irregular, erythematous to haemorrhagic, alopecic papules, plaques, and nodules, with extensive crusting, draining tracts, and ulceration. Cytological findings revealed a marked inflammatory response consisting of non-degenerative and degenerative neutrophils and macrophages, with moderate to abundant intracellular and extracellular Bcc. Ciclosporin and prednisolone were stopped in case 2 after diagnosis. However, it was challenging to stop the regimen in case 1 because of recurrence of immune-mediated polyarthritis and the onset of iatrogenic hypoadrenocorticism. Case 1 did not achieve remission for approximately 66 weeks even with seven protocols because of multiple relapses, whereas it took only three weeks to achieve remission in case 2 while using one drug. Conclusion: For deep pyoderma with extensive lesions in immunosuppressed patients, one should consider infection with Bcc. Therefore, immunosuppressants should promptly be reduced in such patients, and then, intensive antimicrobial therapy may achieve remission.

Background: B. cepacia complex (Bcc) is an emerging pathogenic organism that can cause many nosocomial infections among hospitalized patients. Inadequate laboratory facilities for B. cepacia complex detection and subsequently inappropriate treatment are considered a major cause for poor therapy outcomes. Methods: This project was aimed to investigate phenotype production of ESBL, AmpC, and Carbapenemase among 47 B. cepacia complex isolated from different Sebha health care facilities. Results: Our data showed that 44.68% were ESBL producers, 57.44% were AmpC producers, while only 29.78% produced carbapenemase. In this study, antibiotics susceptibility of Bcc isolates was variable, 100 % resistant to Ticarcillin/clavulanic acid, 85 % resistant to sulfamethoxazole-trimethoprim, 76 % resistant to Ticarcillin/clavulanic Chloramphenicol, 57 % to Ceftazidime, and 55 % to Tetracyclines, 44% to Ciprofloxacin and 31% to Meropenem. Conclusion: In conclusion, this study shows that Bcc species have a higher resistance level attributed to several mechanisms. This high resistance needs careful antimicrobial prescribing regulations, and urgent implementation of infection prevention control is necessary.

During March 2016–January 2019, Burkholderia cepacia complex (BCC) infection developed in 13 persons who inject drugs (PWID) in Kowloon West Region, Hong Kong, China. Seven cases were infective spondylitis, 2 endocarditis, 2 septic arthritis, 1 intramuscular abscess and bacteremia, and 1 necrotizing fasciitis. Pulsed-field gel electrophoresis revealed that the isolates from 9 patients were clonally related. This clone caused major illness, and 11 of the 13 patients required surgical treatment. Clinicians should be aware of this pathogen and the appropriate broad-spectrum antimicrobial drugs to empirically prescribe for PWID with this life-threatening infection. Close collaboration among public health authorities, outreach social workers, and methadone clinics is essential for timely prevention and control of outbreaks in the PWID population.

• Central nervous system infections by Burkholderia cepacia complex are rare. • We report the first case of choroid plexitis caused by B. cepacia complex after severe COVID-19. • The patient recovered after long-term therapy with multiple antibiotics. Burkholderia cepacia complex (BCC) encompasses opportunistic pathogen with various clinical manifestations ranging from no symptoms to severe respiratory infections and septicemia. Central nervous system infections caused by BCC are rare. To the best of our knowledge, we present the first reported case of choroid plexitis caused by BCC after severe COVID-19. A 67-year-old woman who had been previously diagnosed with COVID-19 presented with a mild fever and headache. Gadolinium-enhanced T1-weighted brain magnetic resonance imaging showed contrast effects in the right choroid plexus and encapsulated abscess. Gram staining of cerebrospinal fluid revealed the presence of gram-negative rods. Broad-range polymerase chain reaction amplification of 16S ribosomal RNA from the cerebrospinal fluid, followed by sequence analysis, identified BCC; thus, choroid plexitis caused by BCC was diagnosed. After prolonged antimicrobial treatment with a multiantibiotic regimen, the patient recovered completely. This case highlights the importance of long-term therapy with a carefully selected multiantibiotic regimen to achieve complete recovery after BCC infection. [ABSTRACT FROM AUTHOR]

Purpose: To present varied clinical presentations, surveillance reports, and final visual outcomes of a rare outbreak of cluster endophthalmitis caused by gram-negative, opportunistic bacilli, Burkholderia cepacia complex (Bcc). Methods: Details of five patients who developed postoperative cluster endophthalmitis were collected. For each patient, an undiluted vitreous sample was collected during vitreous tap. Bacterial culture from the vitreous sample in each case had grown Bcc. Surveillance investigations for root cause analysis (RCA) were performed in the operating room (OR), admission, and day-care wards to localize the source. Results: Four patients had undergone phacoemulsification surgery, and one patient had undergone penetrating keratoplasty. Each patient received an initial dose of empiric intravitreal ceftazidime and vancomycin. The organism isolated in each case was sensitive to ceftazidime, cotrimoxazole, and meropenem and resistant to other antibiotics. Core vitrectomy was done after 48–60 hours in four patients along with intravitreal imipenem injection. One patient did not provide consent for core vitrectomy and subsequently developed phthisis bulbi. Three patients had subsequent recurrences. Two patients had a final BCVA of 20/60, two had BCVA better than 20/200, while one patient had no perception of light. None of the surveillance samples from the OR complex could isolate Burkholderia. Conclusion: Extensive OR surveillance should be done to identify the potential source of infection. However, the source may not be identifiable in few instances like in our case. Longer follow-up is recommended in cases of Bcc endophthalmitis due to the persistent nature of the infection.

The Burkholderia cepacia complex (Bcc) comprises a group of 24 species, many of which are opportunistic pathogens of immunocompromised patients and also are widely distributed in agricultural soils. Several Bcc strains synthesize strain-specific antagonistic compounds. In this study, the broad killing activity of B. cenocepacia TAtl-371, a Bcc strain isolated from the tomato rhizosphere, was characterized. This strain exhibits a remarkable antagonism against bacteria, yeast and fungi including other Bcc strains, multidrug-resistant human pathogens and plant pathogens. Genome analysis of strain TAtl-371 revealed several genes involved in the production of antagonistic compounds: siderophores, bacteriocins and hydrolytic enzymes. In pursuit of these activities, we observed growth inhibition of Candida glabrata and Paraburkholderia phenazinium that was dependent on the iron concentration in the medium, suggesting the involvement of siderophores. This strain also produces a previously described lectin-like bacteriocin (LlpA88) and here this was shown to inhibit only Bcc strains but no other bacteria. Moreover, a compound with an m/z 391.2845 with antagonistic activity against Tatumella terrea SHS 2008T was isolated from the TAtl-371 culture supernatant. This strain also contains a phage-tail-like bacteriocin (tailocin) and two chitinases, but the activity of these compounds was not detected. Nevertheless, the previous activities are not responsible for the whole antimicrobial spectrum of TAtl-371 seen on agar plates, suggesting the presence of other compounds yet to be found. In summary, we observed a diversified antimicrobial activity for strain TAtl-371 and believe it supports the biotechnological potential of this Bcc strain as a source of new antimicrobials.

Burkholderia cepacia complex (BCC) is a rare cause of sepsis in neonates, but infections are usually severe. It can be encountered unexpectedly when adequate health care is not provided. In this study, 49 neonatal cases with blood culture-proven BCC bacteremia within the first 72 h following admission to the neonatal intensive care unit between June 2017 and December 2018 were retrospectively analyzed in detail. All but one of the cases were born in Jarabulus, Al Bab, or Aleppo in Syria and were referred to Turkey due to urgent medical treatment needs. The rate of BCC bacteremia among the neonates transferred from across the border was 16.1% (48/297). The most common coexisting problems in the cases were multiple congenital malformations (12.2%), gastrointestinal system atresia (8.2%), and congenital heart diseases (4.1%). The median age at the time of their admission in Turkey was three days, and the median length of stay in another center before the referral was 11.5 h. The case fatality rate was 14.3%. In this study, a high rate of BCC infection and associated mortality was seen in neonates referred from cross-border regions. For centers accepting cases from conflict-affected regions, it is crucial to be careful regarding early detection of bacteremia, planning appropriate treatments, and preventing cross-contamination risks within the unit. [ABSTRACT FROM AUTHOR]

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. [ABSTRACT FROM AUTHOR]

Burkholderia cepacia complex (BCC) has been recognized as a serious cause of pneumonia in patients with cystic fibrosis. BCC infection has also been reported in non-cystic fibrosis patients. Notably, the mortality rate of bacterial pneumonia caused by BCC is high. Nonetheless, therapeutic management of BCC infection remains to be established. Recent reports have indicated successful treatment of BCC pneumonia with combination antibiotic therapy. However, no reports have detailed the efficacy of combination antibiotic therapy for both initial and recurrent BCC pneumonia management. We herein describe a rare case of BCC pneumonia in a non-cystic fibrosis patient that was successfully treated with a combination of intravenous, inhalational and oral antibiotics. Furthermore, antibiotic therapy including inhaled tobramycin has been continued after discharge from hospital, and no side effects or recurrence of bacterial pneumonia has been observed, although BCC has been detected in sputum. The findings of the present case suggest that combination antibiotic therapy including inhaled tobramycin may be effective for recurrent bacterial pneumonia caused by BCC. In the management of BCC infection, early diagnosis should be made based on sputum culture results, and combination antibiotic therapy should be initiated promptly., Competing Interests: The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (© 2024 The Authors.)

Introduction: Burkholderia cepacia complex (Bcc) is a group of gram-negative bacilli that have rarely been isolated in the ear, nose and throat region in immunocompetent patients. Bcc show resistance to most available antibacterial drugs. Case Report: We present the case of an immunocompetent 31-year-old male reporting a pulsating headache with right supraorbital swelling associated with exophthalmos. A brain CT scan showed an expansive giant cystic lesion occupying the right frontal sinus, extending to the anterior cranial fossa. Management and outcome: drainage with the resecting of the floor of the frontal sinus from the orbital plate of the ethmoid bone to the nasal septum (Draf IIb) was performed with wide marsupialization of the mucopyocele. Polymerase chain reaction-restriction fragment length polymorphism (PCR-RFLP) analysis was used to identify the isolate. MRI 1 and 12 months after surgery showed complete lesion removal. The patient was followed for 12 months with complete recovery of symptoms. Conclusion: Paranasal sinuses disease with cranial expansion and orbital complications constitutes an emergency. For the first time in the literature, Bcc was isolated in the frontal sinus, extending into the anterior cranial fossa, in an immunocompetent patient. An endoscopic surgical approach with microbiological identification and management by appropriate antibacterial drug treatment seems to be the key to success.

Both sterile and non-sterile pharmaceutical products, which include antiseptics, have been recalled due to Burkholderia cepacia complex (BCC) contamination. Therefore, minimizing the frequency of outbreaks may be conducive to the development of a quick and sensitive approach that can distinguish between live and dead loads of BCC. We have assessed an exo probe-based recombinase polymerase amplification (RPA) with 10 µM propidium monoazide (PMAxx) for selective detection of live/dead BCC cells in various concentrations of antiseptics (i.e., chlorhexidine gluconate (CHX) and benzalkonium chloride (BZK) solutions) after 24 h. The optimized assay conducted using a set of primer–probes targeting gbpT was performed at 40 °C for 20 min and shows a detection limit of 10 pg/µL of genomic DNA from B. cenocepacia J2315, equivalent to 104 colony-forming units (CFU/mL). The specificity of a newly designed primer and probe was 80% (20 negatives out of 25). The readings for total cells (i.e., without PMAxx) from 200 µg/mL CHX using PMAxx-RPA exo assay was 310 relative fluorescence units (RFU), compared to 129 RFU with PMAxx (i.e., live cells). Furthermore, in 50–500 µg/mL BZK-treated cells, a difference in the detection rate was observed between the PMAxx-RPA exo assay in live cells (130.4–459.3 RFU) and total cells (207.82–684.5 RFU). This study shows that the PMAxx-RPA exo assay appears to be a valid tool for the simple, rapid and presumptive detection of live BCC cells in antiseptics, thereby ensuring the quality and safety of pharmaceutical products.

The Burkholderia cepacia complex comprises environmental and clinical Gram-negative bacteria that infect particularly debilitated people, such as those with cystic fibrosis. Their high level of antibiotic resistance makes empirical treatments often ineffective, increasing the risk of worst outcomes and the diffusion of multi-drug resistance. However, the discovery of new antibiotics is not trivial, so an alternative can be the use of vaccination. Here, the reverse vaccinology approach has been used to identify antigen candidates, obtaining a short-list of 24 proteins. The localization and different aspects of virulence were investigated for three of them—BCAL1524, BCAM0949, and BCAS0335. The three antigens were localized in the outer membrane vesicles confirming that they are surface exposed. We showed that BCAL1524, a collagen-like protein, promotes bacteria auto-aggregation and plays an important role in virulence, in the Galleria mellonella model. BCAM0949, an extracellular lipase, mediates piperacillin resistance, biofilm formation in Luria Bertani and artificial sputum medium, rhamnolipid production, and swimming motility; its predicted lipolytic activity was also experimentally confirmed. BCAS0335, a trimeric adhesin, promotes minocycline resistance, biofilm organization in LB, and virulence in G. mellonella. Their important role in virulence necessitates further investigations to shed light on the usefulness of these proteins as antigen candidates.