Methods: The genomes of 24 MTBC isolated from sputum and pus samples were sequenced. The phenotypic drug susceptibility testing (DST) of the isolates was determined for ten anti-TB drugs. Bioinformatic analysis comprising genome assembly and annotation and single-nucleotide polymorphism (SNP) analysis in genes associated with resistance to the ten anti-TB drugs were done on each sequenced genome.
Results: The draft assemblies covered an average of 97% of the expected genome size. Eleven isolates were aligned to the Indo-Oceanic lineage, eight were East-Asian lineage, three were East African-Indian lineage, and one was of Euro-American and Bovis lineages, respectively. Twelve of the 24 MTBC isolates were phenotypically MDR M. tuberculosis: one is polyresistance and another one is monoresistance. Twenty-six SNPs across nine genes associated with resistance toward ten anti-TB drugs were detected where some of the mutations were found in isolates that were previously reported as pan-susceptible using DST. A haplotype consisting of 65 variants was also found among the MTBC isolates with drug-resistance traits.
Conclusions: This study is the first effort done in Malaysia to utilize 24 genomes of the local clinical MTBC isolates. The high-resolution molecular epidemiological data obtained provide valuable insights into the mechanistic and epidemiological qualities of TB within the vicinity of Southeast Asia.
OBJECTIVE: A series of new pyrazolines containing novel 2,5-dichloro-3-acetylthiophene chalcone moiety (PZT1-PZT20) have been synthesized, characterized by 1HNMR and 13CNMR and evaluated for them in vitro antitubercular activity against M. tuberculosis H37Rv strain and in vitro anticancer activity against DU-145 prostate cancer cell lines and all compounds were also screened for molecular docking studies against specific targeted protein domains.
METHODS: All compounds were screened for potential activity against Mycobacterium tuberculosis H37Rv (MTB) strain and anticancer activity against DU-149 prostate cancer cell lines using MTT cytotoxicity assay.
RESULTS: Among the series, compound PZT5 with 2", 4"-dichlorophenyl group at 5-position on the pyrazoline ring exhibited the most potent antitubercular activity (MIC=1.60 µg/mL) and compounds PZT2, PZT9, PZT11, PZT15, and PZT20 showed similar antitubercular activity against standard pyrazinamide (MIC=3.12 µg/mL) by broth dilution assay. PZT15 and PZT17 with 4"- pyridinyl and 2"-pyrrolyl groups on pyrazoline ring were found to exhibit better anticancer activity against DU-149 prostate cancer cell lines with IC50 values of 2.0±0.2 µg/mL and 6.0±0.3 µg/mL respectively by MTT assay. The preliminary structure-activity relationship has been summarized. The molecular docking studies with crystalline structures of enoyl acyl carrier protein reductase InhA interaction with target protein (2NSD; PDB and 3FNG; PDB) of Mycobacterium tuberculosis H37Rv (MTB) strain have also exhibited good ligand interaction and binding affinity. Ligand interaction and binding affinity were estimated using crystal structures of both types of enoyl acyl carrier protein reductase InhA (3FNG.pdb) and found to be much higher (-16.70 to - 19.20 kcal/mol) compared with pyrazinamide (-10.70 kcal/mol) as a standard target molecule. Whereas the binding affinities of six active compounds with crystal structure of other type of enoyl acyl carrier protein reductase InhA (2NSD.pdb) were much similar and higher (-9.30 to - 11.20 kcal/mole) than pyrazinamide (-11.10 kcal/mole).
CONCLUSION: These new pyrazolines would be promising potent inhibitors of drug sensitive and drug resistant Mycobacterium tuberculosis strain and potential anticancer agents against prostate cancer and other prototypes of cancers.
OBJECTIVE: To obtain population-based data on Mycobacterium tuberculosis drug resistance in Pakistan.
METHODS: To obtain drug resistance data, we conducted a population-based study of TB cases in all provinces of Pakistan. We performed culture and drug susceptibility testing on M. tuberculosis isolates from patients with a prior history of anti-tuberculosis treatment (retreatment cases) from all over the country.
RESULTS: Of 544 isolates from previously treated cases, 289 (53.1%) were susceptible to all first-line drugs, 255 (46.9%) were resistant to at least one anti-tuberculosis drug and 132 (24.3%) were MDR-TB. Among MDR-TB isolates, 47.0% were ofloxacin (OFX) resistant. Extensively drug-resistant TB was found in two (0.4%) isolates.
CONCLUSION: Prevalence of drug resistance in retreatment isolates was high. The alarmingly high prevalence of OFX resistance among MDR-TB isolates may threaten the success of efforts to control and treat MDR-TB.
MATERIALS AND METHODS: In this study, we focus on two important drugs used for TB treatment - rifampicin (RIF) and isoniazid (INH) - and report a detailed study of RIF-loaded poly lactic-co-glycolic acid (PLGA) NPs and INH modified as INH benz-hydrazone (IH2) which gives the same therapeutic effect as INH but is more stable and enhances the drug loading in PLGA NPs by 15-fold compared to INH. The optimized formulation was characterized using particle size analyzer, scanning electron microscopy and transmission electron microscopy. The drug release from NPs and stability of drug were tested in different pH conditions.
RESULTS: It was found that RIF and IH2 loaded in NPs release in a slow and sustained manner over a period of 1 month and they are more stable in NPs formulation compared to the free form. RIF- and IH2-loaded NPs were tested for antimicrobial susceptibility against Mycobacterium tuberculosis H37Rv strain. RIF loaded in PLGA NPs consistently inhibited the growth at 70% of the minimum inhibitory concentration (MIC) of pure RIF (MIC level 1 µg/mL), and pure IH2 and IH2-loaded NPs showed inhibition at MIC equivalent to the MIC of INH (0.1 µg/mL).
CONCLUSION: These results show that NP formulations will improve the efficacy of drug delivery for TB treatment.