Thiosulfinate Tolerance Gene Clusters Are Common Features of Burkholderia Onion Pathogens.

Burkholderia gladioli pv. alliicola, B. cepacia, and B. orbicola are common bacterial pathogens of onion. Onions produce organosulfur thiosulfinate defensive compounds after cellular decompartmentalization. Using whole-genome sequencing and in silico analysis, we identified putative thiosulfinate tolerance gene (TTG) clusters in multiple onion-associated Burkholderia species similar to those characterized in other Allium-associated bacterial endophytes and pathogens. Sequence analysis revealed the presence of three Burkholderia TTG cluster types, with both Type A and Type B being broadly distributed in B. gladioli, B. cepacia, and B. orbicola in both the chromosome and plasmids. Based on isolate natural variation and generation of isogenic strains, we determined the in vitro and in vivo contribution of TTG clusters in B. gladioli, B. cepacia, and B. orbicola. The Burkholderia TTG clusters contributed to enhanced allicin tolerance and improved growth in filtered onion extracts by all three species. TTG clusters also made clear contributions to B. gladioli foliar necrosis symptoms and bacterial populations. Surprisingly, the TTG cluster did not contribute to bacterial populations in onion bulb scales by these three species. Based on our findings, we hypothesize onion-associated Burkholderia may evade or inhibit the production of thiosulfinates in onion bulb tissues. [Formula: see text] Copyright © 2024 The Author(s). This is an open access article distributed under the CC BY-NC-ND 4.0 International license.

Phage Milagro: a platform for engineering a broad host range virulent phage for Burkholderia.

IMPORTANCE: Burkholderia infections are a significant concern in people with CF and other immunocompromising disorders, and are difficult to treat with conventional antibiotics due to their inherent drug resistance. Bacteriophages, or bacterial viruses, are now seen as a potential alternative therapy for these infections, but most of the naturally occurring phages are temperate and have narrow host ranges, which limit their utility as therapeutics. Here we describe the temperate Burkholderia phage Milagro and our efforts to engineer this phage into a potential therapeutic by expanding the phage host range and selecting for phage mutants that are strictly virulent. This approach may be used to generate new therapeutic agents for treating intractable infections in CF patients.

Challenges and mitigation strategies associated with Burkholderia cepacia complex contamination in pharmaceutical manufacturing.

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.

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.

Non-coding regulatory sRNAs from bacteria of the Burkholderia cepacia complex.

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.

Burkholderia cepacia contaminating fresh frozen plasma causing transfusion transmitted bacterial infection.

Bacterial contamination of plasma is unusual owing to frozen storage nevertheless reported. We report a case of transfusion transmitted infection due to Burkholderia cepacia contaminating fresh frozen plasma. A 31 year old male with decompensated chronic liver disease presented with breathlessness due to pleural effusion. Due to elevated prothrombin time, fresh frozen plasma was infused. After ten minutes of transfusion, he became febrile, tachypnoeic and transfusion was stopped. Plasma bag and blood cultures from patient grew B. cepacia. He became hemodynamically unstable due to underlying disease and died after a week.

Bacteriophage steering of Burkholderia cenocepacia toward reduced virulence and increased antibiotic sensitivity.

Antibiotic resistance in bacteria is a growing global concern and has spurred increasing efforts to find alternative therapeutics, such as the use of bacterial viruses, or bacteriophages. One promising approach is to use phages that not only kill pathogenic bacteria but also select phage-resistant survivors that are newly sensitized to traditional antibiotics, in a process called "phage steering." Members of the bacterial genus Burkholderia, which includes various human pathogens, are highly resistant to most antimicrobial agents, including serum immune components, antimicrobial peptides, and polymixin-class antibiotics. However, the application of phages in combination with certain antibiotics can produce synergistic effects that more effectively kill pathogenic bacteria. Herein, we demonstrate that Burkholderia cenocepacia serum resistance is due to intact lipopolysaccharide (LPS) and membranes, and phage-induced resistance altering LPS structure can enhance bacterial sensitivity not only to immune components in serum but also to membrane-associated antibiotics such as colistin. IMPORTANCE Bacteria frequently encounter selection pressure from both antibiotics and lytic phages, but little is known about the interactions between antibiotics and phages. This study provides new insights into the evolutionary trade-offs between phage resistance and antibiotic sensitivity. The creation of phage resistance through changes in membrane structure or lipopolysaccharide composition can simultaneously be a major cause of antibiotic sensitivity. Our results provide evidence of synergistic therapeutic efficacy in phage-antibiotic interactions and have implications for the future clinical use of phage steering in phage therapy applications.

Computational design of prospective molecular targets for Burkholderia cepacia complex by molecular docking and dynamic simulation studies.

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.

Phenazines and toxoflavin act as interspecies modulators of resilience to diverse antibiotics.

Bacterial opportunistic pathogens make diverse secondary metabolites both in the natural environment and when causing infections, yet how these molecules mediate microbial interactions and their consequences for antibiotic treatment are still poorly understood. Here, we explore the role of three redox-active secondary metabolites, pyocyanin, phenazine-1-carboxylic acid, and toxoflavin, as interspecies modulators of antibiotic resilience. We find that these molecules dramatically change susceptibility levels of diverse bacteria to clinical antibiotics. Pyocyanin and phenazine-1-carboxylic acid are made by Pseudomonas aeruginosa, while toxoflavin is made by Burkholderia gladioli, organisms that infect cystic fibrosis and other immunocompromised patients. All molecules alter the susceptibility profile of pathogenic species within the "Burkholderia cepacia complex" to different antibiotics, either antagonizing or potentiating their effects, depending on the drug's class. Defense responses regulated by the redox-sensitive transcription factor SoxR potentiate the antagonistic effects these metabolites have against fluoroquinolones, and the presence of genes encoding SoxR and the efflux systems it regulates can be used to predict how these metabolites will affect antibiotic susceptibility of different bacteria. Finally, we demonstrate that inclusion of secondary metabolites in standard protocols used to assess antibiotic resistance can dramatically alter the results, motivating the development of new tests for more accurate clinical assessment.

In vitro and in vivo activity of cefiderocol against Achromobacter spp. and Burkholderia cepacia complex, including carbapenem-non-susceptible isolates.

Achromobacter spp. and Burkholderia cepacia complex (Bcc) are rare but diverse opportunistic pathogens associated with serious infections, which are often multidrug resistant. This study compared the in vitro antibacterial activity of the siderophore antibiotic cefiderocol against Achromobacter spp. and Bcc isolates with that of other approved antibacterial drugs, including ceftazidime-avibactam, ciprofloxacin, colistin, imipenem-relebactam, and meropenem-vaborbactam. Isolates were collected in the SIDERO multinational surveillance program. Among 334 Achromobacter spp. isolates [76.6% from respiratory tract infections (RTIs)], cefiderocol had minimum inhibitory concentration (MIC)50/90 of 0.06/0.5 µg/mL overall and 0.5/4 µg/mL against 52 (15.6%) carbapenem-non-susceptible (Carb-NS) isolates. Eleven (3.3%) Achromobacter spp. isolates overall and 6 (11.5%) Carb-NS isolates were not susceptible to cefiderocol. Among 425 Bcc isolates (73.4% from RTIs), cefiderocol had MIC50/90 of ≤0.03/0.5 µg/mL overall and ≤0.03/1 µg/mL against 184 (43.3%) Carb-NS isolates. Twenty-two (5.2%) Bcc isolates overall and 13 (7.1%) Carb-NS isolates were not susceptible to cefiderocol. Cumulative MIC distributions showed cefiderocol to be the most active of the agents tested in vitro against both Achromobacter spp. and Bcc. In a neutropenic murine lung infection model and a humanized pharmacokinetic immunocompetent rat lung infection model, cefiderocol showed significant bactericidal activity against two meropenem-resistant Achromobacter xylosoxidans strains compared with untreated controls (P < 0.05) and vehicle-treated controls (P < 0.05), respectively. Meropenem, piperacillin-tazobactam, ceftazidime, and ciprofloxacin comparators showed no significant activity in these models. The results suggest that cefiderocol could be a possible treatment option for RTIs caused by Achromobacter spp. and Bcc.

Comparison of enzymatic activities of lipases from Burkholderia plantarii and Burkholderia cepacia.

Lipases (EC 3.1.1.3) are enzymes used in the oils and fats industries to modify the physicochemical properties of triacylglycerol (TAG). Lipase-catalyzed interesterification at high temperatures is an effective method for modifying the physicochemical properties of TAG. The lipase from Burkholderia plantarii (BpL) exhibits excellent catalytic activity for non-regiospecific interesterification at high temperatures, with depressed lipase hydrolytic activity. The detailed catalytic mechanism for reactions involving catalytic residues has not been elucidated because of the lack of a conventional method for estimating interesterification activity. We used our original water-in-oil emulsion system to estimate the interesterification activity of lipases. BpL showed 10% hydrolytic and 140% interesterification activities compared to the lipase from Burkholderia cepacia, which has a high sequence homology with BpL. By comparing the sequence and crystal structure data of the lipases, we clarified that two amino acids near the active center are one of the factors controlling the hydrolytic and interesterification activities of the enzyme.

Biocontrol of biofilm forming Burkholderia cepacia using a quorum quenching crude lactonase enzyme extract from a marine Chromohalobacter sp. strain D23.

Biofilm plays advantageous role in Burkholderia cepacia by exerting multi-drug resistance. As quorum sensing (QS) system regulates biofilm formation and pathogenicity in B. cepacia strains, quorum quenching (QQ) may be a novel strategy to control persistent B. cepacia infections. In these regards, 120 halophilic bacteria were isolated from marine sample and tested using Chromobacterium violaceum and C. violaceum CV026-based bioassays initially, showing reduced violacein synthesis by QQ enzyme by 6 isolates. Among them, Chromohalobacter sp. D23 significantly degraded both C6-homoserine lactone (C6-HSL) and C8-HSL due to potent lactonase activity, which was detected by C. violaceum CV026 biosensor. Further high-performance liquid chromatography (HPLC) study confirmed degradation of N-acyl homoserine lactones (N-AHLs) particularly C6-HSL and C8-HSL by crude lactonase enzyme. Chromohalobacter sp. D23 reduced biofilm formation in terms of decreased total biomass and viability in biofilm-embedded cells in B. cepacia significantly which was also evidenced by fluorescence microscopic images. An increase in antibiotic susceptibility of B. cepacia biofilm was achieved when crude lactonase enzyme of Chromohalobacter sp. strain D23 was combined with chloramphenicol (1-5 × MIC). Chromohalobacter sp. D23 also showed prominent decrease in QS-mediated synthesis of virulence factors such as extracellular polymeric substances (EPS), extracellular protease, and hemolysin in B. cepacia. Again crude lactonase enzyme of Chromohalobacter sp. strain D23 inhibited B. cepacia biofilm formation inside nasal oxygen catheters in vitro. Finally, antibiotic susceptibility test and virulence tests revealed sensitivity of Chromohalobacter sp. strain D23 against a wide range of conventional antibiotics as well as absence of gelatinolytic, hemolytic, and serum coagulating activities. Therefore, the current study shows potential quorum quenching as well as anti-biofilm activity of Chromohalobacter sp. D23 against B. cepacia.

Burkholderia cepacia immobilized onto rGO as a biomaterial for the removal of naphthalene from wastewater.

As one of the polycyclic aromatic hydrocarbons (PAHs), naphthalene is of serious environmental concern due to its carcinogenicity, persistence and refractory degradation. In this study, a new functional biomaterial based on Burkholderia cepacia (BK) immobilized on reduced graphene oxide (rGO) was prepared, resulting in the removal of 99.0% naphthalene within 48 h. This was better than the 67.3% for free BK and 55.6% for rGO alone. Various characterizations indicated that reduced graphene oxide-Burkholderia cepacia (rGO-BK) was successfully synthesized and secreted non-toxic and degradable surfactants which participated in the degradation of naphthalene. The adsorption kinetics and degradation kinetics conformed best to non-linear pseudo-second-order and pseudo-first-order kinetic models, respectively. Demonstrated in this work is that removing naphthalene by rGO-BK involved both chemically dominated adsorption and biodegradation. As well, GC-MS analysis revealed two things: firstly, that the degraded products of naphthalene were dibutyl phthalate, diethyl phthalate, phthalic acid, and benzoic acid; and secondly, two potentially viable biodegradation pathways of naphthalene by rGO-BK could be proposed. Finally, for practical application experiment, the rGO-BK was exposed to river water samples and generated 99% removal efficiency of naphthalene, so this study offers new insights into biomaterials that can remove naphthalene.

Subtractive sequence analysis aided druggable targets mining in Burkholderia cepacia complex and finding inhibitors through bioinformatics approach.

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.

Pangenome inventory of Burkholderia sensu lato, Burkholderia sensu stricto, and the Burkholderia cepacia complex reveals the uniqueness of Burkholderia catarinensis.

Here the pangenome analysis of Burkholderia sensu lato (s.l.) was performed for the first time, together with an updated analysis of the pangenome of Burkholderia sensu stricto, and Burkholderia cepacia complex (Bcc) focusing on the Bcc B. catarinensis specific features of its re-sequenced genome. The pangenome of Burkholderia s.l., Burkholderia s.s., and of the Bcc was open, composed of more than 96% of accessory genes, and more than 62% of unknown genes. Functional annotations showed that secondary metabolism genes belonged to the variable portion of genomes, which might explain their production of several compounds with varied bioactivities. Taken together, this work showed the great variability and uniqueness of these genomes and revealed an underexplored unknown potential in poorly characterized genes. Regarding B. catarinensis 89T, its genome harbors genes related to hydrolases production and plant growth promotion. This draft genome will be valuable for further investigation of its biotechnological potentials.

Burkholderia cepacia CS8 improves phytoremediation potential of Calendula officinalis for tannery solid waste polluted soil.

Microbes have shown potential for the bioremediation of tannery waste polluted soil. During our previous study, it was observed that heavy metal resistant Burkholderia cepacia CS8 augmented growth and phytoremediation capability of an ornamental plant. Objective of the present research work was to evaluate the capability of B. cepacia CS8 assisted Calendula officinalis plants for the phytoremediation of tannery solid waste (TSW) polluted soil. The TSW treatment significantly reduced growth attributes and photosynthetic pigments in C. officinalis. However, supplementation of B. cepacia CS8 which exhibited substantial tolerance to the TSW amended soil, augmented growth traits, carotenoid, proline, and antioxidant enzymes level in C. officinalis under toxic and nontoxic regimes. Inoculation of B. cepacia CS8 augmented plant growth (shoot length 13%, root length 11%), physiological attributes (chlorophyll a 14%, chlorophyll b 17%), antioxidant enzyme activities (peroxidase 24%, superoxide dismutase 31% and catalase 19%), improved proline 36%, phenol 32%, flavonoids 14% and declined malondialdehyde (MDA) content 15% and hydrogen peroxide (H2O2) level 12% in C. officinalis at TSW10 stress compared with relevant un-inoculated plants of TSW10 treatment. Moreover, B. cepacia CS8 application enhanced labile metals in soil and subsequent metal uptake, such as Cr 19%, Cd 22%, Ni 35%, Fe 18%, Cu 21%, Pb 34%, and Zn 30%, respectively in C. officinalis plants subjected to TSW10 stress than that of analogous un-inoculated treatment. Higher plant stress tolerance and improved phytoremediation potential through microbial inoculation will assist in the retrieval of agricultural land in addition to the renewal of native vegetation.

During the current study, it was observed that combination of Calendula officinalis and metal tolerant Burkholderia cepacia CS8 not only improved plant growth but also helped phyto-extraction of pollutants present in the tannery solid waste polluted soil. According to our information, research work describing the phytoremediation potential of native metal tolerant microbes and ornamental plants has not been reported in Pakistan.

Quorum sensing activities and genomic insights of plant growth-promoting rhizobacteria isolated from Assam tea.

Secretion of quorum sensing (QS) molecules is important for the effective colonization of host plants by plant growth-promoting rhizobacteria. The current study aims at the isolation and characterization of tea rhizo bacteria, which produce the QS molecules, acyl homoserine lactone (AHLs), along with multiple plant growth-promoting (PGP) activities. Thirty-one isolates were isolated from the tea rhizosphere, and screening for PGP activities resulted in the selection of isolates RTE1 and RTE4 with multiple PGP traits, inhibiting the growth of tea fungal pathogens. Both isolates also showed production of AHL molecules when screened using two biosensor strains, Chromobacterium violaceum CV026 and Escherichia coli MT 102(jb132). The isolates identified as Burkholderia cepacia RTE1 and Pseudomonas aeruginosa RTE4 based on genome-based analysis like phylogeny, dDDH, and fastANI calculation. Detailed characterization of AHLs produced by the isolates using reverse-phase TLC, fluorometry, and LC-MS indicated that the isolate RTE1 produced a short chain, C8, and a long chain C12 AHL, while RTE4 produced short-chain AHLs C4 and C6. Confocal microscopy revealed the formation of thick biofilm by RTE1 and RTE4 (18 and 23 µm, respectively). Additionally, we found several genes involved in QS, and PGP, inducing systemic resistance (ISR) activities such as lasI/R, qscR, pqq, pvd, aldH, acdS, phz, Sod, rml, and Pch, and biosynthetic gene clusters like N-acyl homoserine lactone synthase, terpenes, pyochelin, and pyocyanin. Based on the functional traits like PGP, biofilm formation and production of AHL molecules, and genetic potential of the isolates B. cepacia RTE1 and P. aeruginosa RTE4 appear promising candidates to improve the health and growth of tea plantations.

Burkholderia cepacia skin-related ulceration: a case report.

Treatment of infected wounds remains a major challenge for clinicians. Antimicrobial stewardship is an important pillar in wound treatment and, as the role of bacteria in wound repair is not well understood, new treatment options and products are constantly being developed to tackle local infection and biofilm. This case report describes a case of antibiotic-resistant Burkholderia cepacia skin infection and subsequent leg ulceration in an 86-year-old man during the COVID pandemic in Italy, which was successfully treated in a conservative way using 1% acetic acid and silver oxysalts in conjunction with compression bandage.

Cluster of Burkholderia cepacia Complex Infections Associated With Extracorporeal Membrane Oxygenation Water Heater Devices.

BACKGROUND: Burkholderia cepacia complex is a group of potential nosocomial pathogens often linked to contaminated water. We report on a cluster of 8 B. cepacia complex infections in cardiothoracic intensive care unit patients, which were attributed to contaminated extracorporeal membrane oxygenation (ECMO) water heaters. METHODS: In December 2020, we identified an increase in B. cepacia complex infections in the cardiothoracic intensive care unit at Brigham and Women's Hospital. We sought commonalities, sequenced isolates, obtained environmental specimens, and enacted mitigation measures. RESULTS: Whole-genome sequencing of 13 B. cepacia complex clinical specimens between November 2020 and February 2021 identified 6 clonally related isolates, speciated as Burkholderia contaminans. All 6 occurred in patients on ECMO. Microbiology review identified 2 additional B. contaminans cases from June 2020 that may have also been cluster related, including 1 in a patient receiving ECMO. All 8 definite or probable cluster cases required treatment; 3 patients died, and 3 experienced recurrent infections. After ECMO was identified as the major commonality, all 9 of the hospital's ECMO water heaters were cultured, and B. contaminans grew in all cultures. Cultures from air sampled adjacent to the water heaters were negative. Water heater touch screens were culture positive for B. contaminans, and the sink drain in the ECMO heater reprocessing room also grew clonal B. contaminans. Observations of reprocessing revealed opportunities for cross-contamination between devices through splashing from the contaminated sink. The cluster was aborted by removing all water heaters from clinical service. CONCLUSIONS: We identified a cluster of 8 B. cepacia complex infections associated with contaminated ECMO water heaters. This cluster underscores the potential risks associated with water-based ECMO heaters and, more broadly, water-based care for vulnerable patients.

Invasive Burkholderia cepacia Complex Infections among Persons Who Inject Drugs, Hong Kong, China, 2016-2019.

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.