RESUMO
Infectious diseases remain among the most pressing concerns for human health. This issue has grown even more complex with the emergence of multidrug-resistant (MDR) bacteria. To address bacterial infections, nanoparticles have emerged as a promising avenue, offering the potential to target bacteria at multiple levels and effectively eliminate them. In this study, silver nanoparticles (AA-AgNPs) were synthesized using the leaf extract of a medicinal plant, Abroma augusta. The synthesis method is straightforward, safe, cost-effective, and environment friendly, utilizing the leaf extract of this Ayurvedic herb. The UV-vis absorbance peak at 424 nm indicated the formation of AA-AgNPs, with the involvement of numerous functional groups in the synthesis and stabilization of the particles. AA-AgNPs exhibited robust antibacterial and antibiofilm activities against methicillin-resistant Staphylococcus aureus (MRSA) and vancomycin-resistant Enterococci (VRE). The MIC values of AA-AgNPs ranged from 8 to 32 µg/mL. Electron microscopic examination of the interaction of AA-AgNPs with the test bacterial pathogens showed a deleterious impact on bacterial morphology, resulting from membrane rupture and leakage of intracellular components. AA-AgNPs also demonstrated a dose-dependent effect in curtailing biofilm formation below inhibitory doses. Overall, this study highlights the potential of AA-AgNPs in the successful inhibition of both the growth and biofilms of MRSA and VRE bacteria. Following studies on toxicity and dose optimization, such AgNPs could be developed into effective medical remedies against infections.
RESUMO
Background: The prevalence of multidrug-resistant-tuberculosis (MDR-TB) among new and previously treated cases is increasing worldwide as well as in India. Rapid detection of MDR-TB allows the establishment of an effective treatment regimen; minimizes the risk of further resistance, and limits the spread of drug-resistant strains. Early diagnosis of MDR-TB is the need of the hour in high-TB burden countries like India, and GenotypeMTBDRplus is quite sensitive and specific in determining the molecular resistance in drugs such as rifampicin and isoniazid. Methods: The present study was done for molecular detection of rifampicin and isoniazid resistance and resistance patterns among MDR-TB suspects and comparison of resistance patterns among new and previously treated cases by GenoType® MTBDRplus Line Probe Assay. A total of 1268 sputum samples of MDR-TB suspects were subjected to fluorescent microscopy. Fluorescent microscopy positive samples were subjected to GenoType® MTBDRplus (HAIN Lifescience) assay. Results: MDR-TB was detected 11.02%, 20.03% in new and previously treated cases. Among MDR-TB patients S531 L was the most common mutation detected in rpoB gene; 71.43% in new, and 72.17% in previously treated cases. S315T1 was the most common mutation noted in katG gene; 100% in new and 81.74% in previously treated. While in hA gene, it was C15T (7.8%) among previously treated cases. Conclusion: MDR-TB has high prevalence in the western part of Uttar Pradesh, India. Previously treated cases have even more high rate of MDR-TB than new TB cases. The most dominant gene mutations associated with resistance to INH and RIF were observed in codon 315 of the katG gene and codon 531 of the rpoB gene. While comparing the mutation patterns by Genotype MTBDRplus assay, previously treated cases showed more diversity of mutations and had greater number of unknown mutations.