Ramp Research Articles

Molecularly imprinted electrochemiluminescence sensor based on luminol functionalized Co-MOF for rifampicin detection.

A highly sensitive molecularly imprinted electrochemiluminescence (MIECL) sensor was developed for detecting rifampicin (RIF) based on luminol@Co-MOF. Co-MOF had a significant enhancement of ECL signaling in the luminol-O2 system. Molecular imprinted polymers (MIPs) with the introduction of RIF provide new properties for the specific recognition of RIF. A noteworthy decrease in ECL intensity was observed with higher concentrations of RIF. Consequently, the ECL signal was controlled by RIF elution from and adsorption by the MIP, thus establishing a new method for RIF detection. Under optimal conditions, this sensor exhibited linear detection ranges of RIF between 1.0 × 10-11mol L-1 and 1.0 × 10-6mol L-1, with a detection limit of 3.3 × 10-12mol L-1 (S/N = 3). The recoveries ranged between 98.1 and 106.0% in fish samples. This method can be used as a sensitive and rapid method to detect RIF in real samples.

Development and preliminary assessment of the iFIND TBR: all-in- one molecular diagnostic assay for rapid detection of Mycobacterium tuberculosis and rifampicin resistance.

Early and accurate diagnosis of tuberculosis (TB) is crucial for initiating timely treatment and preventing new infections. In this study, we introduced the iFIND TBR assay, an automated all-in-one tuberculosis detection approach that simultaneously detect Mycobacterium tuberculosis (MTB) and rifampicin (RIF) resistance. The limits of detection (LOD), sensitivity, specificity, and RIF-R rpoB mutation detection of the iFIND TBR were tested on Mycobacterium tuberculosis DNA or sputum samples spiked with known numbers of M.tuberculosis H37Rv. Frozen clinical samples from patients suspected of having TB were also tested. The LOD of the iFIND TBR for MTB detection were 13.34 CFU/ml (95% CI, 11.71-16.47), and for RIF resistance was 109.79CFU/mL (95% CI, 95-138.19). The iFIND TBR assay accurately distinguish MTB strains from non-tuberculous mycobacteria (NTM) without any cross reactivity. Testing on 157 clinical sputum samples, compared with the bacteriologically TB standard, the overall sensitivity and specificity of the iFIND TBR was 100% (95%CI, 94.64, 100) and 85.29% (95% CI, 74.61, 92.72), respectively. When assessing RIF susceptibility, the iFIND TBR achieved a sensitivity of 98.15% (95% CI, 90.11-99.95) and a specificity of 85.71% (95% CI, 67.33-95.97), compared with phenotypic drug susceptibility testing. Discordant RIF susceptibility results were more frequently observed in samples exhibiting heteroresistance. These findings demonstrate that iFIND TBR assay performs well in detecting TB and RIF resistance, and shows promise as a point-of-care tool in resource-limited areas.

Rifampicin‐Loaded Nano‐in‐Microparticles (Trojan Particles) as a Pulmonary Delivery System for Tuberculosis Treatment

AbstractThe oral rifampicin (RIF) dosage forms possess various side effects and limited efficacy for tuberculosis treatment. Thus, this work developed the nano‐in‐microparticles containing RIF (trojan nRIF) as a novel pulmonary delivery system. The RIF‐loaded nanoparticles (nRIF) were prepared by self‐assembly polyelectrolyte complexation between lecithin and chitosan, whereas the trojan nRIF were formulated by spray‐drying method of nRIF and mannitol/maltodextrin. The nRIF had a spherical shape with sizes of 86–126 nm, zeta potentials of 24–39 mV, entrapment efficiencies of 44–80 %, and drug loading capacities of 13–42 %. The RIF release from nRIF occurred in two stages, the initially rapid release stage and the controlled release stage upto 96 h, followed the Higuchi model. The trojan nRIF possessed the mass median aerodynamic diameter of 3.7–4.6 μm, fine particle fraction of 34–40 %, and alveolar fraction of 17–21 %. Compared to mannitol, maltodextrin was a superior carrier for nRIF, which yielded better aerodynamic properties and RIF was mainly stayed in the amorphous form. Moreover, using the scanning electron microscopy, the nano‐in‐microparticles were clearly observed with hollow structure. Finally, the trojan nRIF could preserve the physical properties of the encapsulated nRIF. In summary, the trojan nRIF could become a potential inhalation anti‐tuberculosis product.

Rifampicin-Loaded PLGA/Alginate-Grafted pNVCL-Based Nanoparticles for Wound Healing

The topical therapy with rifampicin (RF)-based formulations is beneficial for treating postoperative wound infections and to accelerate healing. Despite recent research highlighting the antibiotic’s significant anti-inflammatory properties, limited topical wound healing products are currently available. The present study aimed to prove that the newly synthesized nanoparticles based on grafted alginate and poly(N-vinylcaprolactam) (pNVCL) and poly-lactic-co-glycolic acid (PLGA) contribute to the healing process of a wound. The methods used were at first the synthesis of the copolymer of alginate and pNVCL via grafting from technique and radical polymerization followed by water-in-oil-in water (W/O/W) emulsification; as oil phase PLGA dissolved in dichloromethane (DCM) was used. The formed nanoparticles were than characterized. The loaded RF was determined to be 160 µg/mL for a 20 mg formulation and within a four-hour time frame approximately 10% of the total loaded amount was released. The inhibitory concentrations (IC50) were 192.1 µg/mL for the nanoparticle, 208.8 µg/mL for pure rifampicin, and 718.1 µg/mL for the rifampicin-loaded nanoparticles. Considering the double role rifampicin was used for, the result was considered satisfactory in the way that these formulations could be used predominantly for postoperative wound irrigation in order to avoid infections and to improve healing.

DFT calculations of structural, chemical, electronic and thermodynamic properties of Rifampicin and Oxalic Acid

The thermodynamic properties of the compounds contribute to the theoretical analysis of the results of favorable energies that are subject to interaction. In this work, through the DFT study, the comparison of the functionals ωB97XD and B3LYP. Geometry optimization calculations and vibrational frequencies were performed for the individual ions and for the interactions. In all cases, all calculated vibrational frequencies are positive, confirming the optimized geometry obtained as a minimum on the potential energy surface. The calculations were carried out in solvent, considering the solvation effect in methanol using the IEFPCM (Integral Equation Formalism of the Polarizable Continuum Model) method. The present work aims to carry out a theoretical study, for in-depth investigations of structural, electronic and thermodynamic properties. In usability in the calculation of the thermodynamic properties, Rifampicin (RIF) and Oxalic Acid (OXA) and the interaction between RIF-OXA in the protonated form protonated RIF with charge +1 and deprotonated OXA with charge -1. In this context, the most favorable thermodynamic parameters in the interaction calculated RIF+-OXA- the values of ∆EZPVE+BSSE, ∆G298 and ∆H in kcal/mol more favorable are -19.62, -14.81 and -25,77.

A novel dual probe-based method for mutation detection using isothermal amplification.

Cost efficient and rapid detection tools to detect mutations especially those linked to drug-resistance are important to address concerns of the rising multi-drug resistance infections. Here we integrated dual probes, namely a calibrator probe and an indicator probe, into isothermal amplification detection system. These two probes are designed to bind distinct regions on the same amplicon to determine the presence or absence of mutation. The calibrator probe signal is used as an internal signal calibrator for indicator probe which detects the presence or absence of the mutation. As an illustrative example, we evaluated the applicability of this dual probe method for detecting mutations associated with rifampicin (RIF) drug resistance at codons 516, 526 and 531 of the rpoB gene in Mycobacterium tuberculosis. In this assessment, we examined 127 artificial samples comprising wild types and mutants with single or multiple mutations. Our results demonstrated 100% accuracy for both wild types and mutants for mutations at codons 526 and 531. As regards to mutations at codon 516, the wild type was identified with 100% accuracy, while the mutants were identified with 95% accuracy. Moreover, when we extended our evaluation to include clinical MTB strains and the Zeptometrix MTB Verification panel, our method achieved 100% accuracy (5 out of 5) in identifying wild-type strains. Additionally, we successfully detected a RIF-resistant strain with mutations at codon 531 of the rpoB gene in Zeptometrix verification panel. Our isothermal mutation detection system, relying on dual probes exhibits a versatile approach. With the capability to identify mutations without prior knowledge of their specific mutation direction, our dual-probe method shows significant promise for applications in drug resistance nucleic acid testing, particularly in resource-limited settings.

Comparative Evaluation of GeneXpert With Ziehl-Neelsen (ZN) Stain in Samples of Suspected Tuberculosis Cases at a Tertiary Care Teaching Hospital in Central India.

Background Tuberculosis (TB) remains a significant public health challenge, particularly in developing countries, where delayed diagnosis contributes to ongoing transmission. Ziehl-Neelsen (ZN) smear microscopy, commonly used for TB diagnosis, has limitations in sensitivity, especially in cases of extrapulmonary tuberculosis (ETB). The GeneXpert Mycobacterium tuberculosis (MTB)/rifampicin (RIF) assay, a molecular diagnostic tool, offers rapid and accurate detection of MTBand RIF resistance. This study aimed to compare the diagnostic efficacy of GeneXpert MTB/RIF with ZN staining in detecting pulmonarytuberculosis (PTB) and ETB. Methods A prospective study was conducted over two years (April 2022 to April 2024) at a tertiary care teaching hospitalin India. A total of 319 clinical samples from patients with suspected PTB and ETB were analyzed. Samples underwent ZN staining and GeneXpert MTB/RIF assay. Sensitivity, specificity, positive predictive value (PPV), and negative predictive value (NPV) were calculated using mycobacterial culture as the gold standard. The chi-square test was employed to compare diagnostic accuracy, with a p-value of <0.05 considered statistically significant. Results Of the 319 samples, ZN staining was positive in 18.2% of cases, while GeneXpert was positive in 21.6%. GeneXpert demonstrated a perfect sensitivity of 100% and a specificity of 98.81%, compared to ZN staining's sensitivity of 84.85% and specificity of 99.21%. GeneXpert showed superior performance in detecting TB in both pulmonary and extrapulmonary samples, with a statistically significant difference (p<0.001). Additionally, GeneXpert identified six cases of RIF resistance. Conclusion The GeneXpert MTB/RIF assay outperforms ZN staining in diagnosing TB, offering higher sensitivity and comparable specificity. Its ability to detect RIF resistance adds significant clinical value. Despite its cost, the integration of GeneXpert into routine diagnostic workflows, particularly in high TB prevalence areas, is recommended to enhance early detection and treatment, thereby reducing TB transmission.

Disrupting Mycobacterium smegmatis biofilm using enzyme-immobilized rifampicin loaded silk fibroin nanoparticles for dual anti-bacterial and anti-biofilm action

Biofilm formation is a major challenge in the treatment of tuberculosis, leading to poor treatment outcomes and latent infections. The complex and dense extracellular polymeric substances (EPS) of the biofilm provides safe harbour for bacterium enabling persistence against anti-TB antibiotics. In this study, we demonstrated that rifampicin-encapsulated silk fibroin nanoparticles immobilized with antibiofilm enzymes can disrupt the Mycobacterium smegmatis biofilm and facilitate the anti-bacterial action of Rifampicin (RIF). The EPS of M.smegmatis biofilm predominantly comprised of lipids (48.8 ± 1.32 %) and carbohydrates (34.8 ± 4.70 %), similar to tuberculosis biofilms. Pre-formed biofilm eradication screening revealed that hydrolytic enzymes such as β-Glucosidase, Glucose oxidase, ɑ-Amylase, Acylase, and Phytase can exhibit biofilm eradication of M.smegmatis biofilms. The enzyme-mediated biofilm disruption was associated with a decrease in hydrophobicity of biofilm surfaces. Treatment with β-glucosidase and Phytase demonstrated a putative biofilm eradication by reducing the total carbohydrates and lipid composition without causing any significant bactericidal activity. Further, Phytase (250 μg/ml) and β-Glucosidase (112.5 ± 17.6 μg/ml) conjugated rifampicin-loaded silk fibroin nanoparticles (R-SFNs) exhibited an enhanced anti-bacterial activity against pre-formed M.smegmatis biofilms, compared to free rifampicin (32.5±7 μg/ml). Notably, treatment with β-glucosidase, Phytase and ɑ-amylase immobilized SFNs decreased the biofilm thickness by ∼98.84 % at 6h, compared to control. Thus, the study highlights that coupling anti-mycobacterial drugs with biofilm-eradicating enzymes such as amylase, phytase or β-glucosidase can be a potential strategy to improve the TB therapeutic outcomes.

Discovery of benzo[c]phenanthridine derivatives with potent activity against multidrug-resistant Mycobacterium tuberculosis.

Mycobacterium tuberculosis (Mtb), the pathogen responsible for tuberculosis (TB), is the leading cause of bacterial disease-related death worldwide. Current antibiotic regimens for the treatment of TB remain dated and suffer from long treatment times as well as the development of drug resistance. As such, the search for novel chemical modalities that have selective or potent anti-Mtb properties remains an urgent priority, particularly against multidrug-resistant (MDR) Mtb strains. Herein, we design and synthesize 35 novel benzo[c]phenanthridine derivatives (BPDs). The two most potent compounds, BPD-6 and BPD-9, accumulated within the bacterial cell and exhibited strong inhibitory activity (MIC90 ~2 to 10 µM) against multiple Mycobacterium strains while remaining inactive against a range of other Gram-negative and Gram-positive bacteria. BPD-6 and BPD-9 were also effective in reducing Mtb survival within infected macrophages, and BPD-9 reduced the burden of Mycobacterium bovis BCG in the lungs of infected mice. The two BPD compounds displayed comparable efficacy to rifampicin (RIF) against non-replicating Mtb (NR-Mtb). Importantly, BPD-6 and BPD-9 inhibited the growth of multiple MDR Mtb clinical isolates. Generation of BPD-9-resistant mutants identified the involvement of the Mmr efflux pump as an indirect resistance mechanism. The unique specificity of BPDs to Mycobacterium spp. and their efficacy against MDR Mtb isolates suggest a potential novel mechanism of action. The discovery of BPDs provides novel chemical scaffolds for anti-TB drug discovery.IMPORTANCEThe emergence of drug-resistant tuberculosis (TB) is a serious global health threat. There remains an urgent need to discover new antibiotics with unique mechanisms of action that are effective against drug-resistant Mycobacterium tuberculosis (Mtb). This study shows that novel semi-synthetic compounds can be derived from natural compounds to produce potent activity against Mtb. Importantly, the identified compounds have narrow spectrum activity against Mycobacterium species, including clinical multidrug-resistant (MDR) strains, are effective in infected macrophages and against non-replicating Mtb (NR-Mtb), and show anti-mycobacterial activity in mice. These new compounds provide promising chemical scaffolds to develop potent anti-Mtb drugs of the future.

Interfacial coupling of sandwich like Zn3V2O8/ZnO/NiCo2S4 nano-heterojunction for the enhanced photocatalytic degradation of rifampicin

The overuse of antibiotics and the release of these pharmaceuticals into the water system has emerged as a serious issue posing a life-threatening environment to aquatic species. In contrast to various contaminants, antibiotics are specifically engineered for durability and efficacy in the system of the human body (human health). Although this design ensures their performance, it also results in their extended longevity and resilience against degradation in natural contexts. These challenges can be addressed by an advanced oxidation process (AOP) utilizing ternary heterojunction nano catalysts (NCs). In this study, the NCs were synthesized through a combination of calcinated-assisted reverse microemulsion and hydrothermal methods. The synthesized NCs were characterized by using various analytical techniques. The enhanced charge separation and migration in Zn3V2O8/ZnO/NiCo2S4 (ZZN) NCs results in 97.3 % degradation of rifampicin (RIF) within 80 min. ZZN NCs exhibit superior catalytic performance under visible light irradiation compared to its pristine Zn3V2O8, ZnO, NiCo2S4, and binary ZnO/NiCo2S4. The enhanced photocatalytic performance can be primarily attributed to the synergetic effects among Zn3V2O8, ZnO, and NiCo2S4 facilitated by the cascade-driven charge transfer mechanism. The prominent reactive oxygen species that participated in photocatalytic degradation activity were found to be superoxide (O2•-) and hydroxide radicals (•OH) which were confirmed through ESR and quenching experiments. From the practical application perspective, ZZN NCs ternary heterostructure demonstrated excellent stability and durability after being recycled six times. This study serve as a vital reference for future investigation into the photocatalytic mechanism related to heterostructure NCs, highlighting their potential for eco-friendly methods to eliminate pollutants and paves a way for manufacturing innovation in near future.

Isoniazid resistance pattern among pulmonary tuberculosis patients in Bangladesh: An exploratory study

ObjectivesIn high tuberculosis (TB) burden countries such as Bangladesh, research and policy tend to focus on rifampicin (RIF)-resistant TB patients, leaving RIF-sensitive but isoniazid (INH)-resistant (Hr-TB) patients undiagnosed. Our study aims to determine the prevalence of INH resistance among pulmonary TB patients in selected health care facilities in Bangladesh. MethodsThis study was conducted across nine TB Screening and Treatment Centres situated in Bangladesh. Sputum samples from 1084 Xpert-positive pulmonary TB patients were collected between April 2021 and December 2022 and cultured for drug susceptibility testing. Demographic and clinical characteristics of Hr-TB and drug-susceptible TB patients were compared. ResultsAmong available drug susceptibility testing results of 998 culture-positive isolates, the resistance rate of any INH regardless of RIF susceptibility was 6.4% (64/998, 95% CI: 4.9–8.2). The rate was significantly higher in previously treated (21.1%, 16/76, 95% CI: 12.0–34.2) compared with newly diagnosed TB patients (5.2%, 48/922, 95% CI: 3.8–6.9) (p < 0.001). The rate of Hr-TB was 4.5% (45/998, 95% CI: 3.3–6.0), which was also higher among previously treated patients (6.6%, 5/76, 95% CI: 1.4–13.5) compared with newly diagnosed TB patients (4.3%; 40/922, 95% CI: 3.1–5.9) (p 0.350). Most importantly, the rate of Hr-TB was more than double compared with MDR-TB (4.5%, 45/998, vs. 1.9%, 19/998) found in the current study. DiscussionThis study reveals a high prevalence of Hr-TB, surpassing even that of the multi-drug-resistant TB in Bangladesh. This emphasizes the urgent need to adopt WHO-recommended molecular tools at the national level for rapid detection of INH resistance so that patients receive timely and appropriate treatment.

The Identification and Characterization of the Resistance Genes of Klebsiella pneumoniae Plasmids Transformed in E. coli BL21(DE3)

The emergence of multidrug-resistant Klebsiella pneumoniae constitutes a serious threat to global public health due to the limited treatment options available. This study aimed to identify some characteristics carried on the plasmids of K. pneumoniae isolated from pathological cases. The plasmid was extracted from K. pneumoniae and transformed into E. coli BL21(DE3) by the heat shock method using 0.1 M CaCl2. The results showed that transformed E. coli BL21(DE3) became resistant to four types of antibiotics which included cefepime (FEP) 10 μg, ceftazidime (CAZ) 30 μg, tetracycline (TE) 10 μg and rifampin (RA) 5 μg. In addition, transforming colonies of E. coli BL21(DE3) were able to producer biofilm as well as production of urease enzyme. The extracted plasmids were digested by 3 types of restriction enzymes (enzyme EcoRI, BamHI and Hind III) to know the restriction sites available in bacterial plasmids. The results showed the presence of some EcoR1 restriction sites by observing the change in the physical shape of the plasmid after being treated with the EcoR1. Meanwhile, no restriction sites were observed for BamH1 and HindIII.

Responding to Hitch in Fighting Mycobacterium Tuberculosis Through Arginine Multi Functionalized Mucoadhesive SNEDDS of Rifampicin.

The study aimed to develop thiolated pluronic-based self-emulsifying drug delivery system (SNEDDS) targeted delivery of Rifampicin coated by arginine for enhanced drug loading, mucoadhesion, muco penetration, site-specific delivery, stabilized delivery against intracellular mycobacterium tuberculosis (M. tb), decreased bacterial burden and production by intracellular targeting. Oleic oil, PEG 200 and Tween 80 are selected as oil, co-surfactant and surfactant based on solubilizing capacity and pseudo ternary diagram region. Coating of thiolated polymer on SNEDDS with ligand arginine (Arg-Th-F407 SNEDDDS) decreased bacterial burden and production by intracellular targeting in macrophages. Formulation are evaluated through scanning electron microscope (SEM), EDAX analysis, diffraction laser scattering (DLS), Fourier transform infrared (FTIR) spectroscopy, and thermal analysis (DSC & TGA). Hydrodynamic diameter of thiolated polymeric SNEDDS (Th-F407 SNEDDS) and Arg-Th-F407 SNEDDS is observed to be 148.4 and 188.5nm with low PDI of 0.4 and 0.3, respectively. Invitro drug release study from Arg-Th-F407 SNEDDS indicates 80% sustained release in 72h under controlled conditions. Arg-Th-F407 SNEDDDS shows excellent capability of killing M.tb strains in macrophages even at low dose as compared to traditional rifampicin (RIF) and is found biocompatible, non-cytotoxic, and hemocompatible. Therefore, Arg-Th-F407 SNEDDDS of RIF proved ideal for targeting and treating M.tb strains within macrophages.

An aerosol nanocomposite microparticle formulation using rifampicin-cyclodextrin inclusion complexes for the treatment of pulmonary diseases

Rifampicin (RIF) is commonly used in the treatment of tuberculosis (TB), a bacterium that currently infects one fourth of the world’s population. Despite the effectiveness of RIF in treating TB, current RIF treatment regimens require frequent and prolonged dosing, leading to decreased patient compliance and, ultimately, increased mortality rates. This project aims to provide an alternative to oral RIF by means of an inhalable spray-dried formulation. TB uses alveolar macrophages to hide and replicate until the cells rupture, further spreading the bacteria. Therefore, delivering RIF directly to the lungs can increase the drug concentration at the site of infection while reducing off-site side effects. Cyclodextrin (CD) was used to create a RIF-CD inclusion complex to increase RIF solubility and biodegradable RIF-loaded NP (RIF NP) were developed to provide sustained release of RIF. RIF NP and RIF-CD inclusion complex were spray dried to form a dry powder nanocomposite microparticles (nCmP) formulation (RIF-CD nCmP). RIF-CD nCmP displayed appropriate aerosol dispersion characteristics for effective deposition in the alveolar region of the lungs (4.0 µm) with a fine particle fraction of 89 %. The nCmP provided both a burst release of RIF due to the RIF-CD complex and pH-sensitive release of RIF due to the RIF NP incorporated into the formulation. RIF-CD nCmP did not adversely affect lung epithelial cell viability and RIF NP were able to effectively redisperse from the nCmP after spray drying. These results suggest that RIF-CD nCmP can successfully deliver RIF to the site of TB infection while providing both immediate and sustained release of RIF. Overall, the RIF-CD nCmP formulation has the potential to improve the efficacy for the treatment of TB.

Plasma and urinary CP I and CP III concentrations in chimeric mice with human hepatocytes after rifampicin administration.

The interest in transporter-mediated drug interactions has been increasing in the field of drug development. In this study, we measured the plasma and urinary concentrations of coproporphyrin (CP) I and CP III as endogenous substrates for organic anion-transporting polypeptide (OATP) using chimeric mice with human hepatocytes (PXB mice) and examined the influence of an OATP inhibitor, rifampicin (RIF). CP I and CP III were actively taken up intracellularly, and RIF inhibited the uptake in a concentration-dependent manner for both CP I and CP III in human hepatocytes (PXB-cells). Single doses of RIF at 10 and 30 mg/kg were orally or intravenously administered to PXB mice and wild-type ICR mice. Plasma concentrations (AUC0-8h) of CP I increased in both mice. However, a marked increase in CP III was only observed in ICR mice, after intravenous administration of RIF at 30 mg/kg. The IC50 values of RIF for intracellular CP I/III uptake and the unbound plasma concentrations of RIF suggested that the increase in plasma CP I is associated with the exposure of RIF to OATPs. The 24-h cumulative urinary excretions of CP I and CP III increased in both mice, but more markedly in PXB mice. Thus, RIF increased the plasma and urinary concentrations of CP I and CP III in the mice, as reported in humans, and CP I may be a more sensitive biomarker of OATP-mediated drug interactions in PXB mice.

Multidrug-resistant tuberculosis clusters and transmission in Taiwan: a population-based cohort study.

Multidrug-resistant tuberculosis (MDR-TB) remains a challenge in the TB program of Taiwan, where 0.5% of new cases and 2.1% of previously treated cases were resistant to at least rifampin (RIF) and isoniazid (INH). Since >80% of our MDR-TB are new cases, genotyping of MDR Mycobacterium tuberculosis is implemented to facilitate contact investigation, cluster identification, and outbreak delineation. This is a population-based retrospective cohort study analyzing MDR-TB cases from 2019 to 2022. Whole genome sequencing (WGS) was performed using the Illumina MiSeq and analyzed using the TB Profiler. A single nucleotide polymorphism (SNP) threshold of ≤ 12 and phylogenetic methods were used to identify putative transmission clusters. An outbreak was confirmed using genomic data and epidemiologic links. Of the 297 MDR-TB cases, 246 (82.8%), 45 (15.2%), and 6 (2.0%) were simple MDR, extensively drug-resistant tuberculosis (pre-XDR-TB) and extensively drug-resistant tuberculosis (XDR-TB), respectively. The sublineage 2.2 modern Beijing was the predominant (48.8%) MDR-TB strain in Taiwan. Phylogenetic analysis identified 25.3% isolates in 20 clusters, with cluster sizes ranging from 2 to 13 isolates. Nevertheless, only 2 clusters, one household and one community, were confirmed as outbreaks. In this study, we found that males had a higher risk of MDR-TB transmission compared to females, and those infected with the sublineage 2.1-proto-Beijing genotype isolates were at a higher risk of transmission. Furthermore, 161 (54.2%) isolates harbored compensatory mutations in the rpoC and non-rifampicin resistant determinant region (non-RRDR) of the rpoB gene. MDR-TB strains containing rpoB S450L and other compensatory mutations concurrently were significantly associated with clusters, especially the proto-Beijing genotype strains with the compensatory mutation rpoC E750D or the modern Beijing genotype strains with rpoC D485Y/rpoC E1140D. Routine and continuous surveillance using WGS-based analysis is recommended to warn of risks and delineate transmission clusters of MDR-TB. We proposed the use of compensatory mutations as epidemiological markers of M. tuberculosis to interrupt putative MDR-TB transmission.

Endogenously doped mixed-oxide CoO/Co2O3 in ZIF-derived carbon deposited on graphite felt for electrochemical oxidation of pharmaceutics

Some of the important goals in the development of the electro-Fenton (EF) process are to increase the performance of the electrodes while reducing their size as an alternative for expensive electrodes, expanding the active pH range, and also generating reactive oxygen species (ROSs) directly without using other homo/heterogeneous catalysts. This work modified graphite felt (GF) using a rapid and in-situ synthesis with Co/Zn doped mixed-metal ZIF. After calcination, various physicochemical analyses, including XRD, SEM, and XPS, confirmed that a carbonic material doped with mixed-oxide CoO/Co2O3 is embedded on the surface of GF fibers. LSV analysis showed that the modification significantly improved the electrode activity for O2 reduction. The modified CoZnCal-GF electrode showed good performance and higher kinetics in the EF process. It removed 87% of rifampin (RIF) in a short period of 30 min without any homo/heterogeneous catalysts. The selected conditions for this process were 1.0 V, 40 mg/L, and 5.6 for applied voltage, initial RIF concentration, and pH, respectively. The non-radical species 1O2 showed the most important role in removing RIF. LC-MS analysis was performed, and while confirming the complete removal of RIF, it was used to investigate the degradation pathway and identify the produced intermediates.

Trehalose catalytic shift is an intrinsic factor in Mycobacterium tuberculosis that enhances phenotypic heterogeneity and multidrug resistance.

Drug-resistance (DR) in many bacterial pathogens often arises from the repetitive formation of drug-tolerant bacilli, known as persisters. However, it is unclear whether Mycobacterium tuberculosis (Mtb), the bacterium that causes tuberculosis (TB), undergoes a similar phenotypic transition. Recent metabolomics studies have identified that a change in trehalose metabolism is necessary for Mtb to develop persisters and plays a crucial role in metabolic networks of DR-TB strains. The present study used Mtb mutants lacking the trehalose catalytic shift and showed that the mutants exhibited a significantly lower frequency of the emergence of DR mutants compared to wildtype, due to reduced persister formation. The trehalose catalytic shift enables Mtb persisters to survive under bactericidal antibiotics by increasing metabolic heterogeneity and drug tolerance, ultimately leading to development of DR. Intriguingly, rifampicin (RIF)-resistant bacilli exhibit cross-resistance to a second antibiotic, due to a high trehalose catalytic shift activity. This phenomenon explains how the development of multidrug resistance (MDR) is facilitated by the acquisition of RIF resistance. In this context, the heightened risk of MDR-TB in the lineage 4 HN878 W-Beijing strain can be attributed to its greater trehalose catalytic shift. Genetic and pharmacological inactivation of the trehalose catalytic shift significantly reduced persister formation, subsequently decreasing the incidence of MDR-TB in HN878 W-Beijing strain. Collectively, the trehalose catalytic shift serves as an intrinsic factor of Mtb responsible for persister formation, cross-resistance to multiple antibiotics, and the emergence of MDR-TB. This study aids in the discovery of new TB therapeutics by targeting the trehalose catalytic shift of Mtb.

Antibiotic resistance challenge: evaluating anthraquinones as rifampicin monooxygenase inhibitors through integrated bioinformatics analysis

ObjectiveAntibiotic resistance poses a pressing and crucial global public health challenge, leading to significant clinical and health-related consequences. Substantial evidence highlights the pivotal involvement of rifampicin monooxygenase (RIFMO) in the context of antibiotic resistance. Hence, inhibiting RIFMO could offer potential in the treatment of various infections. Anthraquinones, a group of organic compounds, have shown promise in addressing tuberculosis. This study employed integrated bioinformatics approaches to evaluate the potential inhibitory effects of a selection of anthraquinones on RIFMO. The findings were subsequently compared with those of rifampicin (RIF), serving as a positive control inhibitor.MethodsThe AutoDock 4.0 tool assessed the binding free energy between 21 anthraquinones and the RIFMO catalytic cleft. The ligands were ranked based on the most favorable scores derived from ΔGbinding. The docking analyses for the highest-ranked anthraquinone and RIF underwent a cross-validation process. This validation procedure utilized the SwissDock server and the Schrödinger Maestro docking software. Molecular dynamics simulations were conducted to scrutinize the stability of the backbone atoms in free RIFMO, RIFMO-RIF, and RIFMO complexed with the top-ranked anthraquinone throughout a 100-ns computer simulation. The Discovery Studio Visualizer tool visualized interactions between RIFMO residues and ligands. An evaluation of the pharmacokinetics and toxicity profiles of the tested compounds was also conducted.ResultsFive anthraquinones were indicated with ΔGbinding scores less than − 10 kcal/mol. Hypericin emerged as the most potent RIFMO inhibitor, boasting a ΔGbinding score and inhibition constant value of − 12.11 kcal/mol and 798.99 pM, respectively. The agreement across AutoDock 4.0, SwissDock, and Schrödinger Maestro results highlighted hypericin’s notable binding affinity to the RIFMO catalytic cleft. The RIFMO-hypericin complex achieved stability after a 70-ns computer simulation, exhibiting a root-mean-square deviation of 0.55 nm. Oral bioavailability analysis revealed that all anthraquinones except hypericin, sennidin A, and sennidin B may be suitable for oral administration. Furthermore, the carcinogenicity prediction analysis indicated a favorable safety profile for all examined anthraquinones.ConclusionInhibiting RIFMO, particularly with anthraquinones such as hypericin, holds promise as a potential therapeutic strategy for infectious diseases.

Unveiling the complexity of rifampicin drug susceptibility testing in Mycobacterium tuberculosis: comparative analysis with next-generation sequencing.

Introduction. The discordance between phenotypic and molecular methods of rifampicin (RIF) drug susceptibility testing (DST) in Mycobacterium tuberculosis poses a significant challenge, potentially resulting in misdiagnosis and inappropriate treatment.Hypothesis/gap statement. A comparison of RIF phenotypic and molecular methods for DST, including whole genome sequencing (WGS), may provide a better understanding of resistance mechanisms.Aim. This study aims to compare RIF DST in M. tuberculosis using two phenotypic and molecular methods including the GeneXpert RIF Assay (GX) and WGS for better understanding.Methodology. The study evaluated two phenotypic liquid medium methods [Lowenstein-Jensen (LJ) and Mycobacterium Growth Indicator Tube (MGIT)], one targeted molecular method (GX), and one WGS method. Moreover, mutational frequency in ponA1 and ponA2 was also screened in the current and previous RIF resistance M. tuberculosis genomic isolates to find their compensatory role.Results. A total of 25 RIF-resistant isolates, including nine from treatment failures and relapse cases with both discordant and concordant DST results on LJ, MGIT and GX, were subjected to WGS. The phenotypic DST results indicated that 11 isolates (44%) were susceptible on LJ and MGIT but resistant on GX. These isolates exhibited multiple mutations in rpoB, including Thr444>Ala, Leu430>Pro, Leu430>Arg, Asp435>Gly, His445>Asn and Asn438>Lys. Conversely, four isolates that were susceptible on GX and MGIT but resistant on LJ were wild type for rpoB in WGS. However, these isolates possessed several novel mutations in the PonA1 gene, including a 10 nt insertion and two nonsynonymous mutations (Ala394>Ser, Pro631>Ser), as well as one nonsynonymous mutation (Pro780>Arg) in PonA2. The discordance rate of RIF DST is higher on MGIT than on LJ and GX when compared to WGS. These discordances in the Delhi/CAS lineages were primarily associated with failure and relapse cases.Conclusion. The WGS of RIF resistance is relatively expensive, but it may be considered for isolates with discordant DST results on MGIT, LJ and GX to ensure accurate diagnosis and appropriate treatment options.