Drug resistance in Candida albicans isolates and related changes in the structural domain of Mdr1 protein.

BACKGROUND: The increasing azole drug resistance in fungal pathogens poses a pressing threat to global health care. The coexistence of drug-resistant Candida albicans with tuberculosis patients and the failure of several drugs to treat C. albicans infection extend hospital stay, economic burden, and death. The misuse or abuse of azole-derived antifungals, chronic use of TB drugs, different immune-suppressive drugs, and diseases like HIV, COVID-19, etc., have aggravated the situation. So it is vital to understand the molecular changes in drug-resistant genes to modify the treatment to design an alternative mechanism. METHOD: C. albicans isolated from chronic tuberculosis patients were screened for antifungal sensitivity studies using disk diffusion assay. The multidrug-resistant C. albicans were further screened for molecular-level changes in drug resistance using MDR1 gene sequencing and compared with Gen bank data of similar species using the BLAST tool. RESULTS: The investigation proved that the isolated C. albicans from TB patients are significantly resistant to the action of six drugs. The molecular changes in MDR1 genes showed differences in seven nucleotide base pairs that interfered with the efflux pump.

Synthesis of silver nanoparticles using gum Arabic: Evaluation of its inhibitory action on Streptococcus mutans causing dental caries and endocarditis.

BACKGROUND: Streptococcus mutans are an oral pathogen that causes dental caries, endocarditis, and systemic dysfunctions, an alternative antibacterial solution from silver nanoparticles (AgNPs) are investigated. METHODS: AgNPs were synthesized using the ethnobotanical product gum Arabic. It influenced the nanoparticles with medicinal value through their role as capping, stabilizing, or surface-attached components. The biophysical characteristics of the synthesized AgNPs were studied using UV-vis spectrum, XRD, EDAX, SEM, and TEM tools. The AgNPs were spherical with the average size less than 10 nm. By using the well diffusion and microdilution techniques, the impact of synthesized AgNPs was tested against S. mutans isolates. RESULTS: The smaller the size, the greater the antibacterial and antiviral potential the particles exhibit. The biophysical characteristics of AgNPs the presence of phenols, alcohols, amides, sulfoxide, flavanoids, terpenoids and steroids. The AgNPs exhibited a good antibacterial action against the oral pathogen S. mutans. The synthesized NPs at a dose level of 200 µg/mL exhibited an inhibition zone with 18.30 ± 0.5 nm diameter. The synthesised nanoparticles inhibited the genes responsible for biofilm formation of S. mutans over host tooth and gums (gtfB, gtfc, gtfD) and virulent protective factors (comDE, brpA and smu 360) and survival promoter genes (gyrA and spaP, gbpB). CONCLUSION: The potent antibiotic action over S. mutans seen with the synthesized NPs, paves the way for the development of novel dental care products. Also, the small-sized NPs promote its applicability in COVID-19 pandemic containment.