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Cell Reports May 2024Quorum sensing (QS) is a cell-to-cell communication mechanism mediated by small diffusible signaling molecules. Previous studies showed that RpfR controls Burkholderia...
Quorum sensing (QS) is a cell-to-cell communication mechanism mediated by small diffusible signaling molecules. Previous studies showed that RpfR controls Burkholderia cenocepacia virulence as a cis-2-dodecenoic acid (BDSF) QS signal receptor. Here, we report that the fatty acyl-CoA ligase DsfR (BCAM2136), which efficiently catalyzes in vitro synthesis of lauryl-CoA and oleoyl-CoA from lauric acid and oleic acid, respectively, acts as a global transcriptional regulator to control B. cenocepacia virulence by sensing BDSF. We show that BDSF binds to DsfR with high affinity and enhances the binding of DsfR to the promoter DNA regions of target genes. Furthermore, we demonstrate that the homolog of DsfR in B. lata, RS02960, binds to the target gene promoter, and perception of BDSF enhances the binding activity of RS02960. Together, these results provide insights into the evolved unusual functions of DsfR that control bacterial virulence as a response regulator of QS signal.
PubMed: 38748879
DOI: 10.1016/j.celrep.2024.114223 -
Microbiology Spectrum May 2024Across the Burkholderia genus -linked protein glycosylation is highly conserved. While the inhibition of glycosylation has been shown to be detrimental for virulence in...
UNLABELLED
Across the Burkholderia genus -linked protein glycosylation is highly conserved. While the inhibition of glycosylation has been shown to be detrimental for virulence in complex species, such as , little is known about how specific glycosylation sites impact protein functionality. Within this study, we sought to improve our understanding of the breadth, dynamics, and requirement for glycosylation across the glycoproteome. Assessing the glycoproteome across different culture media using complementary glycoproteomic approaches, we increase the known glycoproteome to 141 glycoproteins. Leveraging this repertoire of glycoproteins, we quantitively assessed the glycoproteome of using Data-Independent Acquisition (DIA) revealing the glycoproteome is largely stable across conditions with most glycoproteins constitutively expressed. Examination of how the absence of glycosylation impacts the glycoproteome reveals that the protein abundance of only five glycoproteins (BCAL1086, BCAL2974, BCAL0525, BCAM0505, and BCAL0127) are altered by the loss of glycosylation. Assessing Δ (ΔBCAL0525), Δ (ΔBCAL0127), and ΔBCAM0505 strains, we demonstrate the loss of FliF, and to a lesser extent MotB, mirror the proteomic effects observed in the absence of glycosylation in Δ. While both MotB and FliF are essential for motility, we find loss of glycosylation sites in MotB or FliF does not impact motility supporting these sites are dispensable for function. Combined this work broadens our understanding of the glycoproteome supporting that the loss of glycoproteins in the absence of glycosylation is not an indicator of the requirement for glycosylation for protein function.
IMPORTANCE
is an opportunistic pathogen of concern within the Cystic Fibrosis community. Despite a greater appreciation of the unique physiology of gained over the last 20 years a complete understanding of the proteome and especially the O-glycoproteome, is lacking. In this study, we utilize systems biology approaches to expand the known glycoproteome as well as track the dynamics of glycoproteins across growth phases, culturing media and in response to the loss of glycosylation. We show that the glycoproteome of is largely stable across conditions and that the loss of glycosylation only impacts five glycoproteins including the motility associated proteins FliF and MotB. Examination of MotB and FliF shows, while these proteins are essential for motility, glycosylation is dispensable. Combined this work supports that glycosylation can be dispensable for protein function and may influence protein properties beyond stability.
PubMed: 38709084
DOI: 10.1128/spectrum.00346-24 -
AMA Journal of Ethics May 2024Burkholderia cenocepacia (B cenocepacia) is a gram-negative bacteria associated with significant morbidity and mortality following lung transplantation. Most US...
Burkholderia cenocepacia (B cenocepacia) is a gram-negative bacteria associated with significant morbidity and mortality following lung transplantation. Most US transplant programs consider B cenocepacia colonization to be an absolute contraindication to transplantation. This article argues that, if clinicians have good clinical reasons to expect poor outcomes for patients with B cenocepacia, then offering transplantation anyway is an abrogation of clinicians' fiduciary duties. This article also discusses other fiduciary obligations transplant programs might have to patients with B cenocepacia, such as referring to another transplant center, considering novel treatment options, and investigating how the infection's virulence factors stratify that patient's risk for poor transplant outcomes.
Topics: Humans; Lung Transplantation; Burkholderia Infections; Burkholderia cenocepacia; Drug Resistance, Bacterial; United States; Organ Transplantation; Anti-Bacterial Agents; Health Services Accessibility
PubMed: 38700520
DOI: 10.1001/amajethics.2024.367 -
Vaccines Apr 2024complex infections remain life-threatening to cystic fibrosis patients, and due to the limited eradication efficiency of current treatments, novel antimicrobial...
complex infections remain life-threatening to cystic fibrosis patients, and due to the limited eradication efficiency of current treatments, novel antimicrobial therapies are urgently needed. Surface proteins are among the best targets to develop new therapeutic strategies since they are exposed to the host's immune system. A surface-shaving approach was performed using J2315 to quantitatively compare the relative abundance of surface-exposed proteins (SEPs) expressed by the bacterium when grown under aerobic and microaerophilic conditions. After trypsin incubation of live bacteria and identification of resulting peptides by liquid chromatography coupled with mass spectrometry, a total of 461 proteins with ≥2 unique peptides were identified. Bioinformatics analyses revealed a total of 53 proteins predicted as localized at the outer membrane (OM) or extracellularly (E). Additionally, 37 proteins were predicted as moonlight proteins with OM or E secondary localization. B-cell linear epitope bioinformatics analysis of the proteins predicted to be OM and E-localized revealed 71 SEP moieties with predicted immunogenic epitopes. The protegenicity higher scores of proteins BCAM2761, BCAS0104, BCAL0151, and BCAL0849 point out these proteins as the best antigens for vaccine development. Additionally, 10 of the OM proteins also presented a high probability of playing important roles in adhesion to host cells, making them potential targets for passive immunotherapeutic approaches. The immunoreactivity of three of the OM proteins identified was experimentally demonstrated using serum samples from cystic fibrosis patients, validating our strategy for identifying immunoreactive moieties from surface-exposed proteins of potential interest for future immunotherapies development.
PubMed: 38675780
DOI: 10.3390/vaccines12040398 -
Materials (Basel, Switzerland) Feb 2024Common walkingstick () aqueous extract (CWSAE) can induce the synthesis of useful bionanomaterials. CWSAE is rich in water-soluble organic compounds such as proteins and...
Study on the Influence of UV Light on Selective Antibacterial Activity of Silver Nanoparticle Synthesized Utilizing Protein/Polypeptide-Rich Aqueous Extract from The Common Walkingstick, .
Common walkingstick () aqueous extract (CWSAE) can induce the synthesis of useful bionanomaterials. CWSAE is rich in water-soluble organic compounds such as proteins and polypeptides that function as reducing/stabilizing agents for nanoparticle formation from Ag ion precursors. The synthesized AgNPs exhibited a moderately uniform size, with the majority falling within the range of 20-80 nm. These AgNPs were UV-treated and tested as antibacterial agents to inhibit the growth of four pathogenic bacteria ( K-56, ST258, PAO1, and USA300), as well as one common bacterium ( BW25113). The disk diffusion test demonstrated that the UV-treated AgNPs significantly and selectively inhibited the growth of USA300 and , while showing a small effect on the other two species. This suggests the potential application of green-chemically synthesized AgNPs as selective antibacterial agents. Furthermore, we studied the effects of short-term (1-2 min) and long-term (5-30 min) UV treatment on the selective cytotoxicity of the AgNPs and found that the cytotoxicity of the AgNPs could depend on the duration of UV exposure against certain bacteria.
PubMed: 38591619
DOI: 10.3390/ma17030713 -
Journal of Oncology 2024Aberrant glycosylation in tumor cells is a hallmark during carcinogenesis. KRAS gene mutations are the most well-known oncogenic abnormalities but their association with...
Aberrant glycosylation in tumor cells is a hallmark during carcinogenesis. KRAS gene mutations are the most well-known oncogenic abnormalities but their association with glycan alterations in pancreatic ductal adenocarcinoma (PDAC) is largely unknown. We employed patient-derived 3D organoids to culture pure live PDAC cells, excluding contamination by fibroblasts and immune cells, to gasp the comprehensive cancer cell surface glycan expression profile using lectin microarray and transcriptomic analyses. Surgical specimens from 24 PDAC patients were digested and embedded into a 3D culture system. Surface-bound glycans of 3D organoids were analyzed by high-density, 96-lectin microarrays. KRAS mutation status and expression of various glycosyltransferases were analyzed by RNA-seq. We successfully established 16 3D organoids: 14 PDAC, 1 intraductal papillary mucinous neoplasm (IPMN), and 1 normal pancreatic duct. KRAS was mutated in 13 (7 G12V, 5 G12D, 1 Q61L) and wild in 3 organoids (1 normal duct, 1 IPMN, 1 PDAC). Lectin reactivity of AAL () and AOL () with binding activity to 1-3 fucose was higher in organoids with KRAS mutants than those with KRAS wild-type. (1-3fucosyltransferase 6) and (1-3/4 fucosyltransferase 3) expression was also higher in KRAS mutants than wild-type. Meanwhile, mannose-binding lectin (rRSL [] and rBC2LA []) signals were higher while those of galactose-binding lectins (rGal3C and rCGL2) were lower in the KRAS mutants. We demonstrated here that PDAC 3D-cultured organoids with KRAS mutations were dominantly covered in increased fucosylated glycans, pointing towards novel treatment targets and/or tumor markers.
PubMed: 38528852
DOI: 10.1155/2024/1529449 -
Cells Feb 2024spp. are often resistant to antibiotics, and infections with these organisms are difficult to treat. A potential alternative treatment for spp. infections is...
spp. are often resistant to antibiotics, and infections with these organisms are difficult to treat. A potential alternative treatment for spp. infections is bacteriophage (phage) therapy; however, it can be difficult to locate phages that target these bacteria. Prophages incorporated into the bacterial genome have been identified within spp. and may represent a source of useful phages for therapy. Here, we investigate whether prophages within spp. clinical isolates can kill conspecific and heterospecific isolates. Thirty-two spp. isolates were induced for prophage release, and harvested phages were tested for lytic activity against the same 32 isolates. Temperate phages were passaged and their host ranges were determined, resulting in four unique phages of prophage origin that showed different ranges of lytic activity. We also analyzed the prophage content of 35 spp. clinical isolate genomes and identified several prophages present in the genomes of multiple isolates of the same species. Finally, we observed that isolates were more phage-susceptible than isolates. Overall, our findings suggest that prophages present within spp. genomes are a potentially useful starting point for the isolation and development of novel phages for use in phage therapy.
Topics: Humans; Prophages; Genome, Viral; Bacteriophages; Burkholderia; Burkholderia cepacia complex; Burkholderia Infections
PubMed: 38474392
DOI: 10.3390/cells13050428 -
Vaccines Feb 2024Despite advances in therapies, bacterial chronic respiratory infections persist as life-threatening to patients suffering from cystic fibrosis (CF). and bacteria of the...
Despite advances in therapies, bacterial chronic respiratory infections persist as life-threatening to patients suffering from cystic fibrosis (CF). and bacteria of the complex are among the most difficult of these infections to treat, due to factors like their resistance to multiple antibiotics and ability to form biofilms. The lack of effective antimicrobial strategies prompted our search for alternative immunotherapies that can effectively control and reduce those infections among CF patients. Previous work from our group showed that the anti-BCAL2645 goat polyclonal antibody strongly inhibited to adhere and invade cultured epithelial cells. In this work, we showed that the polyclonal antibody anti-BCAL2645 also strongly inhibited the ability of to form biofilms, and to adhere and invade the human bronchial epithelial cell line CFBE41o-. The polyclonal antibody also inhibited, to a lesser extent, the ability of to adhere and invade the human bronchial epithelial cell line CFBE41o. We also show that the ability of , and to kill larvae of the model of infection was impaired when bacteria were incubated with the anti-BCAL2645 antibody prior to the infection. Our findings show that an antibody against BCAL2645 possesses a significant potential for the development of new immunotherapies against these three important bacterial species capable of causing devastating and often lethal infections among CF patients.
PubMed: 38400190
DOI: 10.3390/vaccines12020207 -
The ISME Journal Jan 2024Bacterivorous protists are thought to serve as training grounds for bacterial pathogens by subjecting them to the same hostile conditions that they will encounter in the...
Bacterivorous protists are thought to serve as training grounds for bacterial pathogens by subjecting them to the same hostile conditions that they will encounter in the human host. Bacteria that survive intracellular digestion exhibit enhanced virulence and stress resistance after successful passage through protozoa but the underlying mechanisms are unknown. Here we show that the opportunistic pathogen Burkholderia cenocepacia survives phagocytosis by ciliates found in domestic and hospital sink drains, and viable bacteria are expelled packaged in respirable membrane vesicles with enhanced resistance to oxidative stress, desiccation, and antibiotics, thereby contributing to pathogen dissemination in the environment. Reactive oxygen species generated within the protozoan phagosome promote the formation of persisters tolerant to ciprofloxacin by activating the bacterial SOS response. In addition, we show that genes encoding antioxidant enzymes are upregulated during passage through ciliates increasing bacterial resistance to oxidative radicals. We prove that suppression of the SOS response impairs bacterial intracellular survival and persister formation within protists. This study highlights the significance of protozoan food vacuoles as niches that foster bacterial adaptation in natural and built environments and suggests that persister switch within phagosomes may be a widespread phenomenon in bacteria surviving intracellular digestion.
Topics: Animals; Humans; Anti-Bacterial Agents; Burkholderia cenocepacia; SOS Response, Genetics; Predatory Behavior; Oxidative Stress
PubMed: 38366016
DOI: 10.1093/ismejo/wrae014 -
Scientific Reports Feb 2024Mining has led to severe environmental pollution in countries with exhaustive mining production and inadequate industrial waste regulation. Microorganisms in...
Mining has led to severe environmental pollution in countries with exhaustive mining production and inadequate industrial waste regulation. Microorganisms in contaminated sites, like mine tailings, have adapted to high concentrations of heavy metals, developing the capacity of reducing or removing them from these environments. Therefore, it is essential to thoroughly characterize bacteria present in these sites to find different ways of bioremediation. In this regard, in this study, an enrichment and isolation procedure were performed to isolate bacteria with lower nutritional requirements and high tolerance to Cu(II) and Fe(II) from two Sonoran River basin mining tails. Two Staphylococcus species and a Microbacterium ginsengisoli strain were isolated and identified from the San Felipe de Jesús mining tail. Also, three strains were isolated from the Nacozari de García mining tail: Burkholderia cenocepacia, Sphingomonas sp. and Staphylococcus warneri. Significant microbiological differences were found between the two sites. All these species exhibited tolerance up to 300 mg/L for Cu (II)-Fe (II) solutions, indicating their capacity to grow in these conditions. Moreover, a consortium of isolated bacteria was immobilized in two different biocomposites and the biocomposite with larger pore size achieved greater bacterial immobilization showcasing the potential of these bacteria in biotechnological applications.
Topics: Metals, Heavy; Industrial Waste; Mining; Biodegradation, Environmental; Bacteria; Soil Pollutants
PubMed: 38351239
DOI: 10.1038/s41598-024-54090-0