QUANTITATIVE ANALYSIS OF GYRA AND GYRB KNOWN MUTATIONS IN DRUG-RESISTANT MYCOBACTERIUM TUBERCULOSIS STRAINS TREATED WITH OFLOXACIN

Objective: The aim of the study is to measure the minimum inhibitory concentrations (MICs) of ofloxacin antibiotic from gyrA and gyrB mutations present in fluoroquinolones (FQs) resistant strains of Mycobacterium tuberculosis (MTB) and to further concentrate the potential association between gene mutations and phenotypic resistance based on their MICs.&#x0D; Methods: Different levels of ofloxacin MICs levels were detected in 31 archived multi drug-resistant MTB isolates showing gyrA mutations in codon at A90V, S91P, D94A, D94N/Y, D94 G, and D94H and two gyrB probes (N538D and E540V). The MIC determinations were made using the 1% proportion method.&#x0D; Results: Genotypic assay detected 32 mutations in the gyrA (n=29) and gyrB (n=3) genes among the 31 FQs resistant isolates. Most frequently seen in gyrA mutations at codon D94G (n=16; 50%), these mutations had a clearly elevated MIC level from 2 to 16 μg/ml, that was phenotypically resistant. The A90V mutation region consistently exhibited the lowest levels of ofloxacin resistance, with three out of eight (37.50%) of these isolates had a MIC of &lt;2 μg/ml. In addition, a further strain of S91P mutations for MIC was determined to be less than the critical concentration (CC). These low levels of resistance have been detected in a phenotypic manner which is noticeable in the study. Furthermore, fewer mutations in codons at D94A, D94N/Y were identified. Three wild-type absent isolates from gyrB QRDR were identified and the MIC of those strains for ofloxacin was lower than the critical cutoff value.&#x0D; Conclusion: Based on the results, it is shown that different resistance mutations were associated with different levels of MICs and the current concentration for MGIT will be lowered from 2 μg/ml to 1 μg/ml for the ofloxacin drug.</jats:p

QUANTITATIVE ANALYSIS OF GYRA AND GYRB KNOWN MUTATIONS IN DRUG-RESISTANT MYCOBACTERIUM TUBERCULOSIS STRAINS TREATED WITH OFLOXACIN

Objective: The aim of the study is to measure the minimum inhibitory concentrations (MICs) of ofloxacin antibiotic from gyrA and gyrB mutations present in fluoroquinolones (FQs) resistant strains of Mycobacterium tuberculosis (MTB) and to further concentrate the potential association between gene mutations and phenotypic resistance based on their MICs. Methods: Different levels of ofloxacin MICs levels were detected in 31 archived multi drug-resistant MTB isolates showing gyrA mutations in codon at A90V, S91P, D94A, D94N/Y, D94 G, and D94H and two gyrB probes (N538D and E540V). The MIC determinations were made using the 1% proportion method. Results: Genotypic assay detected 32 mutations in the gyrA (n=29) and gyrB (n=3) genes among the 31 FQs resistant isolates. Most frequently seen in gyrA mutations at codon D94G (n=16; 50%), these mutations had a clearly elevated MIC level from 2 to 16 μg/ml, that was phenotypically resistant. The A90V mutation region consistently exhibited the lowest levels of ofloxacin resistance, with three out of eight (37.50%) of these isolates had a MIC of &lt;2 μg/ml. In addition, a further strain of S91P mutations for MIC was determined to be less than the critical concentration (CC). These low levels of resistance have been detected in a phenotypic manner which is noticeable in the study. Furthermore, fewer mutations in codons at D94A, D94N/Y were identified. Three wild-type absent isolates from gyrB QRDR were identified and the MIC of those strains for ofloxacin was lower than the critical cutoff value. Conclusion: Based on the results, it is shown that different resistance mutations were associated with different levels of MICs and the current concentration for MGIT will be lowered from 2 μg/ml to 1 μg/ml for the ofloxacin drug

Immunoglobulin G1 binding with various molecular receptors: A new paradigm of IgG1 as a potential adjuvant

Objective: To explore the possible IgG1 binding receptors by protein-protein docking experiments. Methods: The protein-protein cognate interactions such as IgG with Fc Receptors (FcRs) potentiate signaling cascades to ameliorate antigen uptake, processing and presentation are studied by protein-protein docking experiments. Results: However, the propensity of IgG interactions with other cognate receptors largely remains obscure. In this direction, possibilities of IgG1 binding with various five receptors were explored. In this study, we report previously unidentified associations between IgG1 and other receptors. Herein, we show that IgG1 binds to the granulocyte-macrophage receptor, β common receptor and complementary receptor(complementary receptor I and complementary receptor II) to form a complex structure. We show the binding ability and important protein-protein interactions of IgG1 with four receptors in comparison to Fc Receptor, and also find out the conserved amino acids and hydrophobic-hydrophobic interactions amongst them. Conclusions: Comparative interaction studies of IgG1 binding to various receptors revealed close similarities of IgG1 binding to its native receptor Fc. In conclusion, our study has shown the comparable binding efficiency of four receptors to IgG1 apart from the conventional Fc receptor

Current Perceptionson Advanced Molecular Diagnostics for Drug-Resistant Mycobacterium tuberculosis

Globally, rising drug-resistant tuberculosis is a significant public health concern. Prompt diagnosis of tuberculosis and detection of drug-resistant TB within a clinically appropriate timeframe is important for the effective management of the disease. Imaging approaches Chest X-rays, CT, MRI, nuclear medicine technique as PET/CT are non-specific, plays an important role in the diagnosis and assessment of TB, but PET/CT sometimes results in false-positive or negative due to benign lesions.Currently using the point of care molecular modalities, Gene Xpert MTB/RIF and line probe assays focused only on resistance-conferring mutations in specific target hotspot regions, but did not identify novel mutations, outside mutations and they may miss some locally prevalent rifampicin-conferring mutations, and not provided a large number of antibiotics/antibiotic groups that are used for DRTB treatment.Recently revolutionized high throughput next generation sequencing (NGS) technologies are offering new prospects for molecular diagnosis, for example, infectious disease pathogens like tuberculosis, influenza, and most recently SARS-CoV-2. NGS is an essential resource for the tuberculosis communityeither target, WGS, or NGS; a rapid method that offers a complete spectrum of Mycobacterium tuberculosis resistance mutations, strain typing for transmission surveillance, unlike traditional molecular or phenotypic DST. It shall be helpful for early regimen design and TB management before mutations emerge and therefore, we believe that the worldwide TB infection will be eliminated by the use of NGS.</jats:p

Versatile pH-Responsive Chitosan-g-Polycaprolactone/Maleic AnhydrideIsoniazid Polymeric Micelle To Improve the Bioavailability of Tuberculosis Multidrugs

The potential of polymeric micelles constructed by coalescing natural and synthetic polymers for tuberculosis (TB) treatment was evaluated in this work. We designed a polymeric micelle to improve the delivery of anti-TB drugs (rifampicin [RF] and isoniazid [INH]). The polymeric core was synthesized in the following order: initially chitosan (CS) was grafted with polycaprolactone (PCL) to form CS-g-PCL followed by amide bond formation with maleic anhydride–isoniazid (MA-INH); finally, CS-g-PCL was conjugated with the MA-INH moiety to form the CS-g-PCL/MA-INH polymeric core. Another anti-TB drug, RF, was loaded onto CS-g-PCL/MA-INH through dialysis. The changes in the nature of functional groups and crystallinity were investigated by Fourier transform infrared spectroscopy and X-ray diffraction analysis, respectively. The shape and size of CS-g-PCL/MA-INH and RF-CS-g-PCL/MA-INH were analyzed by dynamic light scattering, scanning electron microscopy, and transmission electron microscopy. The cumulative drug release profiles were measured by UV–visible spectrophotometry and HPLC analysis. The antimicrobial activity of the loaded micelles was evaluated by finding the minimum inhibitory concentration (MIC), minimum bactericidal concentration (MBC), and bacterial cell rupture analyses. The nontoxic nature of the micelles was assessed by ex vivo studies on U937 and L929 cell lines and erythrocytes by performing an MTT assay, apoptosis assay, and hemolysis assay. Ex vivo cellular uptake and in vivo internalization of the INH- and RF-containing micelles were tested on U937 cells and zebrafish using fluorescence microscopy analysis. All of the observations indicate that the multi-TB drug-loaded polymeric micelle is a safe and effective system for the delivery of anti-TB drugs without affecting the mycobactericidal activity

Mutational Stability Profiling and Functional Analysis of Spike Protein in Indian Sars Cov-2 Delta Variants: an in Silico Analysis

Abstract Context Globally Severe acute respiratory syndrome coronavirus-2 (SARS CoV-2) is the most influential pandemic which affects the human respiratory system. The severity of the disease depends on the interaction between the viral protein and host protein. Spike protein of SARS-CoV-2 interacts with host ACE2 receptor in the presence of TMPRSS serine protease through C-Terminal Domain (CTD). In this research, we studied the effect of mutation on the S-protein stability and functional analysis based on the sequence of SARS CoV-2 delta Indian variants by in silico prediction. Sequences were retrieved from the database and studied mutation and evolutionary relationships. The protein stability is analyzed by predicting intrinsic disorder and I-Mutant v2.0 bioinformatics tool. The functional study of S-protein was conducted using SMART, Protparam, NetPhos, and NetNGlyc. In addition to this analysed the stability of RBD region after mutation. Methods This study explains the effect of mutation on spike proteins and its evolutionary relationship, which is used for the better understanding of SARS CoV-2 variation and diversification. The changes in spike protein promote the evolution of the virus. In the future, a complete analysis of delta variant S protein contributes to effective targeted therapeutic measures.</jats:p