Inhalable Particles for "Pincer Therapeutics" Targeting Nitazoxanide as Bactericidal and Host-Directed Agent to Macrophages in a Mouse Model of Tuberculosis.

Nitazoxanide (NTZ) has moderate mycobactericidal activity and is also an inducer of autophagy in mammalian cells. High-payload (40-50% w/w) inhalable particles containing NTZ alone or in combination with antituberculosis (TB) agents isoniazid (INH) and rifabutin (RFB) were prepared with high incorporation efficiency of 92%. In vitro drug release was corrected for drug degradation during the course of study and revealed first-order controlled release. Particles were efficiently taken up in vitro by macrophages and maintained intracellular drug concentrations at one order of magnitude higher than NTZ in solution for 6 h. Dose-dependent killing of Mtb and restoration of lung and spleen architecture were observed in experimentally infected mice treated with inhalations containing NTZ. Adjunct NTZ with INH and RFB cleared culturable bacteria from the lung and spleen and markedly healed tissue architecture. NTZ can be used in combination with INH-RFB to kill the pathogen and heal the host.

Report of rpoB mutation in clinically suspected cases of drug resistant leprosy: a study from Eastern India.

BACKGROUND: The current strategy for leprosy control depends mainly on early case detection and providing the recommended multidrug therapy (MDT) dosage. Understanding the molecular mechanisms of drug resistance to each of these drugs is essential in providing effective treatment and preventing the spread of resistant strains in the community. The progress of molecular biology research provides a very efficient opportunity for the diagnosis of drug resistance by in vitro method. AIM: We aimed to investigate the point mutations within the rpoB gene region of the Mycobacterium leprae genome, which are responsible for resistance to rifampicin, in order to determine the emergence of drug resistance in leprosy in the Kolkata region of West Bengal. METHODS: A total of 50 patients with a relapse of leprosy were enrolled in the study. Skin smears were obtained for estimation of bacillary index and biopsies were obtained in 70% alcohol for extraction of DNA. The extracted DNA was amplified by M. leprae-polymerase chain reaction (PCR) targeting rpoB gene region. Every single nucleotide base in the sequence is aligned to reference sequence and identity gaps were determined by NCBI - BLAST. Later in-silico analysis was done to identify the changes in the translated protein sequences. RESULTS: A mutation at the base pair position 2275405 where G is replaced by C in the M. leprae genome, which corresponds to the coding region of rpoB gene (279 bp - 2275228 to2275506), was observed in two patients. This missense mutation in CAC codon brings about a glutamic acid to histidine change in the amino acid sequence of RNA polymerase beta subunit at the position 442 (Glu442His), a region specific for rifampicin interaction, which might be responsible for unresponsiveness to rifampicin by manifesting a stable bacteriological index in these 2 patients even after completion of 24 months of multibacillary multi-drug therapy (MB-MDT). LIMITATIONS: The major limitations of multiple-primer PCR amplification refractory mutation system (MARS) assay is that it capable of detecting mutation at codon 425 and cannot distinguish any silent amino acid changes. CONCLUSION: The study indicates the existence of rifampicin drug resistance in Eastern India.

Mannosylated gelatin nanoparticles bearing isoniazid for effective management of tuberculosis.

The mannosylated gelatin nanoparticles (Mn-GNPs) were prepared for the selective delivery of an antitubercular drug, isoniazid (INH), to the alveolar macrophages. The gelatin nanoparticles (GNPs) were prepared by using a two-step desolvation method and efficiently conjugated with mannose. Various parameters such as particle size, polydispersity index, zeta potential, % entrapment efficiency, in vitro drug release, macrophage uptake, in vivo biodistribution, antitubercular activity and hepatotoxicity of plain and Mn-GNPs were determined. The size of nanoparticles (both plain and Mn-GNPs) was found to be in range of 260-380 nm, and maximum drug payload was found to be 40-55%. Average particle size of Mn-GNPs was more, whereas drug entrapment was lesser compared to plain GNPs. The organ distribution studies demonstrated the efficiency of Mn-GNPs for spatial delivery of INH to alveolar tissues. Intravenous administration of INH loaded Mn-GNPs (I-Mn-GNPs) resulted in significant reduction in bacterial counts in the lungs and spleen of tuberculosis-infected (TB-infected) mice and also reduction in the hepatotoxicity of the drug. This study revealed that mannose conjugated GNPs may be explored as potential carrier for safer and efficient management of TB through targeted delivery of INH when compared to plain GNPs and free drug.