Project description:Burkholderia mallei and Burkholderia pseudomallei are both potential biological threats agents. Melioidosis caused by B. pseudomallei is endemic in Southeast Asia and Northern Australia, while glanders caused by B. mallei infections are rare. Here we studied the proteomes of different B. mallei and B. pseudomallei isolates to determine species specific characteristics. Analyzing the expressed proteomes of B. mallei and B. pseudomallei revealed differences between B. mallei and B. pseudomallei but also between isolates from the same species. Expression of multiple virulence factors and proteins of several PKS/NRPS clusters was demonstrated. Proteome analysis can be used not only to identify bacteria but also to characterize the expression of important factors that putatively contribute to pathogenesis of B. mallei and B. pseudomallei.
Project description:Gene expression profiles of human cell (THP-1) lines exposed to a novel Daboiatoxin (DbTx) isolated from Daboia russelli russelli, and specific cytokines and inflammatory pathways involved in acute infection caused by Burkholderia pseudomallei. Keywords: Melioidosis, Burkholderia pseudomallei, Daboiatoxin, Cytokines, Inflammation.
Project description:Burkholderia pseudomallei is the causative agent of melioidosis a disease endemic in South-East Asia and Northern Australia. The mortality rates in these areas are unacceptably high even with antibiotic treatment, attributed to intrinsic and acquired resistance of B. pseudomallei to antibiotics. With very few options for therapeutics there is an urgent requirement to identify anti-bacterial targets for the development of novel, effective treatments. In this study we examine the role and effect of ppiB on the proteome. Using LFQ analysis we show loss of ppiB has dramatic effect on the Burkholderia pseudomallei proteome.
Project description:To use whole genome microarrays to compare the differences in genome contents of 5 B. pseudomallei isolated from clinical specimens and environmental sample with B. pseudomallei K96243 reference strain and reveals variable patterns of Genomic Islands (GIs) Keywords: Comparative genomic hybridization DNA microarrays were used to compare genome of clinical and environmental B. pseudomallei isolates with B. pseudomallei K96243 reference strain (B. pseudomallei K96243 vs. B. pseudmallei isolates). Each hybridization was used for comparison between B. pseudomallei K96243 as a reference strain with environmental isolate BP45s, environmental isolate BP28L, clinical isolate H307, clinical isolate P54, clinical isolate P82. Two replicate per array. Multiple hits with 90-99.99 % identity correspond to other locus are replicate of their genes were averaged and analyzed.
Project description:Gene expression profiles of human cell (THP-1) lines exposed to a novel Daboiatoxin (DbTx) isolated from Daboia russelli russelli, and specific cytokines and inflammatory pathways involved in acute infection caused by Burkholderia pseudomallei. Experiment Overall Design: 1. Group I:- Human monocytic macrophage (THP-1) cell lines grown in the culture medium without any bacterial infection served as untreated control group (Three Biological Replicates). Experiment Overall Design: 2. Group II:- THP-1 cells were infected with Burkholderia pseudomallei (A600 nm = OD 0.6, ~5 x 107 cfu/ml) for 24h served as a disease control group (Three Biological Replicates). Experiment Overall Design: 3. Group III:- THP-1 cells were infected with B. pseudomallei and treated with Daboiatoxin (0.5 mM) isolated from Daboia russelli russelli venom served as a treatment group (Three Biological Replicates). Experiment Overall Design: 4. Group IV:- THP-1 cells were infected with B. pseudomallei (A600 nm = OD 0.6, ~5 x 107 cfu/ml) treated with standard antimicrobial drug ceftazidime (10mg/ml) served as a drug control (Three Biological Replicates). Experiment Overall Design: 5. Group V:- THP-1 cells were exposed to Daboiatoxin (0.5 mM) without bacterial infection (Three Biological Replicates).
Project description:Natural isolates of Burkholderia pseudomallei (Bp), the causative agent of melioidosis, are known to exhibit diverse phenotypic traits, suggesting significant intraspecies genetic heterogeneity. Using whole-genome Bp microarrays, we experimentally mapped patterns of large-scale genomic variation in 93 South East Asian clinical, environmental, and animal Bp isolates. 14% of the reference Bp K96243 genome was variably present across the strain panel, more than double previous estimates, and both hypothetical proteins and paralogous gene pairs (PGPs) were significantly over-represented in the set of strain-variable genes. Examining patterns of PGP retention and loss, we successfully sub-categorized the PGPs into non-redundant, functionally biased, and completely redundant classes. We then identified 20 novel regions (âislandsâ) variably present between strains previously missed by computational analysis. Three of these novel islands contained lipopolysaccharide (LPS) biosynthesis genes, and strains lacking one such LPS island demonstrated reduced virulence in mouse infection assays. Clinical isolates associated with human melioidosis were strongly associated with the presence of specific genomic islands, but a common set of virulence-related genes was present in all strains. Our results suggest that most Bp strains possess a core virulence machinery capable of causing disease, but accessory functions provided by mobile elements may predispose distinct host species and ecological niches to specific individual strains. This hierarchical model of Bp virulence reconciles previous conflicting studies comparing Bp environmental and clinical isolates, and suggests novel molecular strategies for disease surveillance and outbreak detection efforts in melioidosis. Keywords: aCGH of 93 Bp strains genomic DNA of 93 Bp strains were assessed on Bp_array_v2
Project description:B. pseudomallei strain K96243 is sensitive to the drug ceftazidime (CAZ), but has been shown to exhibit transient CAZ tolerance when in a biofilm form. To investigate an observed shift in gene expression profile during ceftazidime (CAZ) tolerance and to better understand the mechanistic aspects of this transient tolerance, RNA-sequencing was performed on B. pseudomallei K96243 from the following three growth states: planktonic-free, biofilm, and planktonic shedding cells. Results indicated that the expression of 651 genes (10.97%) were significantly changed in both biofilm (resistant) and planktonic shedding (sensitive) cells in comparison to the planktonic state. Burkholderia biofilm shifts its transcriptome in response to ceftazidime exposure by regulating iron-sulfur stabilizing and metabolic-related genes.
Project description:Candida auris is an emerging multidrug-resistant human fungal pathogen often refractory to treatment by all classes of antifungal drugs. Amphotericin B (AmB) is a fungicidal drug that, despite its toxic side effects, remains a drug of choice for the treatment of drug-resistant fungal infections, including those caused by C. auris. However, the molecular mechanisms underlying AmB resistance are poorly understood. In this study, we present data that suggests membrane lipid alterations and chromatin modifications are critical processes that contribute to or cause adaptive AmB resistance in clinical C. auris isolates. To determine the plausible cause of increased AmB resistance, we performed RNA-seq of AmB-resistant and sensitive C. auris isolates. Remarkably, AmB-resistant strains show a pronounced enrichment of genes involved in lipid and ergosterol biosynthesis, adhesion, drug transport as well as chromatin remodeling. The transcriptomics data confirm increased adhesion and reduced lipid membrane permeability of AmB-resistant strains compared to the sensitive isolates. The AmB-resistant strains also display hyper-resistance to cell wall perturbing agents, including congo red, calcofluor white and caffeine. Additionally, we noticed an increased phosphorylation of Mkc1 cell integrity MAP kinase upon AmB treatment. Collectively, these data identify differences in the transcriptional landscapes of AmB-resistant vs AmB-senstive isolates, and provide a framework for the mechanistic understanding of AmB resistance in C. auris.