Custom design microarray for molecular drug susceptibility testing and strain typing of tuberculosis
Ontology highlight
ABSTRACT: After performing multiplex PCR, we analysed extracted DNA (500 ng ssDNA) from 9 Mycobacterium tuberculosis clinical isolates to detect multidrug resistance. In addition, a mixed strain situation was simulated by mixing wild type Mtb CDC1551 (20 ng) with 4 concentrations of Mtb mutant DNA (1 ng, 250 pg, 62.5 pg, and 15.6 pg), which is equivalent to relative concentrations of 5%, 1.25%, 0.31% and 0.08% Mtb mutant DNA.
Project description:Tuberculosis (TB) is one of the deadliest infectious disorders in the world. To effectively TB manage, an essential step is to gain insight into the lineage of Mycobacterium tuberculosis (MTB) strains and the distribution of drug resistance. Although the Campania region is declared a cluster area for the infection, to contribute to the effort to understand TB evolution and transmission, still poorly known, we have generated a dataset of 159 genomes of MTB strains, from Campania region collected during 2018-2021, obtained from the analysis of whole genome sequence data. The results show that the most frequent MTB lineage is the 4 according for 129 strains (81.11%). Regarding drug resistance, 139 strains (87.4%) were classified as multi susceptible, while the remaining 20 (12.58%) showed drug resistance. Among the drug-resistance strains, 8 were isoniazid-resistant MTB (HR-MTB), 7 were resistant only to one antibiotic (3 were resistant only to ethambutol and 3 isolate to streptomycin while one isolate showed resistance to fluoroquinolones), 4 multidrug-resistant MTB, while only one was classified as pre-extensively drug-resistant MTB (pre-XDR). This dataset expands the existing available knowledge on drug resistance and evolution of MTB, contributing to further TB-related genomics studies to improve the management of TB infection.
Project description:SDL-TOPO protocol was applied for the detection of lagging-strand in replicating budding yeast strain. Genomic DNA was extracted from cdc9 mutant strain, and served for library preparation with SDL-TOPO. To see the sensitivity of SDL-TOPO for the detection of lagging strand, various amounts of genomic DNA were used for the library preparation: 75 ng, 25 ng, 7.5 ng, 2.5 ng, 750 pg, 250 pg, 75 pg, and 25 pg. The prepared libraries were sequenced on Illumina iSeq100 with paired-end mode of 150x2. Only read 1 was served for mapping with bowtie2 against reference sequence sacSer3. The mapped reads were separated strand specifically, and read depths were visualized. The strand-biased mapping patterens were observed for libraries prepared from each amount of input DNA.
Project description:ChIP-seq is used to map transcription factor occupancy and generate epigenetic profiles genome-wide. The requirement of nano-scale ChIP DNA for generation of sequencing libraries has impeded ChIP-seq on in vivo tissues of low cell numbers. We describe a robust, simple and scalable methodology for ChIP-seq of low-abundant cell populations, reliably amplifying 50 pg of ChIP DNA, corresponding to ~30,000 input cells for transcription factor ChIP (CEBPA) and 3,000 cells for histone mark ChIP (H3K27me3). This represents a significant advance compared to existing technologies, which involve complex and time-consuming steps of pre-amplification, making them susceptible to experimental biases. ChIP-seq of histone modifications H3K27me3 (2 biological replicates (I+II) , 2 ng input), H3K4me3 (2 biological replicates (II+III), 2 ng input), transcription factor CEBPA (2 biological replicates (I+II), 300 pg input), 4 diluted CEBPA libraries (pool of ChIP from 3 biol. replicates (I+II+III) 3x 100 pg input, 1x 50 pg). Additonal ChIP-seq using 10,000 cells, 1 biological replicate of each H3K4me3 and CEBPA.
Project description:Mycobacterium tuberculosis (Mtb) is the causative agent of tuberculosis, the leading cause of death among all infectious diseases. There are 11 eukaryotic-like serine/threonine protein kinases (STPKs) in Mtb, which are thought to play pivotal roles in cell growth, signal transduction and pathogenesis. However, their underlying mechanisms of action remain largely uncharacterized. In this study, using a Mtb proteome microarray, we have globally identified the binding proteins in Mtb for all of the STPKs, and constructed the first STPK protein interaction (KPI) map that includes 492 binding proteins and 1,027 interactions. Bioinformatics analysis showed that the interacting proteins reflect diverse functions, including roles in two-component system, transcription, protein degradation, and cell wall integrity. Functional investigations confirmed that PknG regulates cell wall integrity through key components of peptidoglycan (PG) biosynthesis, e.g., MurC. The global STPK-KPIs network constructed here is expected to serve as a rich resource for understanding the key signaling pathways in Mtb, thus facilitating drug development and effective control of Mtb.
Project description:Deeper understanding of the crosstalk between host cells and Mycobacterium tuberculosis (Mtb) provides crucial guidelines for the rational design of novel intervention strategies against tuberculosis (TB). Mycobacteria possess a unique complex cell wall with arabinogalactan (AG) as critical component. AG has been identified as a virulence factor of Mtb which is recognized by host galectin-9. Here we demonstrate that galectin-9 directly inhibited mycobacterial growth through AG-binding property of carbohydrate-recognition domain 2. Furthermore, IgG antibodies with AG specificity were detected in serum of TB patients. Based on the interaction between galectin-9 and AG, we developed monoclonal antibody (mAb) screening assay and identified AG-specific mAbs which profoundly inhibit Mtb growth. Mechanistically, proteomic profiling and morphological characterizations revealed that AG-specific mAbs regulate AG biosynthesis, thereby inducing cell wall swelling. Thus, direct AG-binding by galectin-9 or antibodies contributes to protection against TB. Our findings pave the way for the rational design of novel immunotherapeutic strategies for TB control.
Project description:Comparison of two different multiplex PCR primer pools in amplifying target HPV types from plasmid templates. Template concentrations are either 1 ng or 1 pg. Templates are detected by type-spcific LDR probes hybridized on microarray.
Project description:During our efforts to isolate potantial binding partners of Esat6, we isolated few peptides rich in phenylalanine residues that strongly interacted with Esat6. All peptides were less than fifty amino acids in length, One of them, Hcl1, when expressed in mycobacteria showed significant retardation in growth and survival within macrophages. Microarray analysis showed that Hcl1 affects a host of genes and cellular pathways. RNA was isolated from exponentially growing mycobacteria containing either plasmid vector pVV16 encoding peptide or vector pVV16 alone. Comparisons were made between Experimental (Mtb/Hcl1) and control (Mtb/pVV16) samples by extracting raw intensity values from multiple arrays.
Project description:Mycobacterium tuberculosis is the causitive agent of TB, which is a global epidemic that has claimed millions of lives. Some clinical strains of M.tb have significantly more severe clinical outcomes, while some other mycobacteria ordinarily do not cause disease in humans. The biological processes underpinning this difference are poorly understood. Thus, this project aimed to identify proteomic differences between more virulent strains of the MTBC (Beijing, J37Rv, CAS and LAM) vs those strains that only cause disease in severely immune compromised humans (Bovis, Smegmatis and Avium). We hypothesise that these differences may offer insight into the molecular mechanisms by which M.tb has become more virulent by evading drug treatment or evading the host immune system more effectively.
Project description:Mtb was cultured in 7H12 media containing cholesterol and exposed to experimental compounds V-12-003679, V-12-007958, V-12-007960 for 6 hours at 10x IC50.
Project description:The gene expression profiles of Mtb after treatment at the minimal inhibitory concentration (MIC) or 4 X MIC at an early stage (up to 6 hours) was compared to untreated Mtb. Our experiment is designed to in order to ensure that the primary effects (0-6h) of the drugs and any dose (1X MIC and 4X MIC) responses would be captured.