The novel SARS-CoV-2 coronavirus, the causative agent of the ongoing pandemic COVID-19 disease continues to infect people globally and has infected millions of humans worldwide. However, no effecti...

This study evaluates the impact of industrially prepared TiO₂ nanoparticles on the biological system by using an in vitro model of colon cancer cell lines (HCT116). Industrial synthesis of titanium oxide nanoparticles was mimicked on the lab scale by the high-energy ball milling method by milling bulk titanium oxide particles for 5, 10, and 15 h in an ambient environment. The physiochemical characterization by field emission scanning electron microscopy, dynamic light scattering, and UV–visible spectroscopy revealed alteration in the size and surface charge with respect to increase in the milling time. The size was found to be reduced to 82 ± 14, 66 ± 12, and 42 ± 10 nm in 5, 10, and 15 h milled nano TiO₂ from 105 ± 12 nm of bulk TiO₂, whereas the zeta potential increased along with the milling time in all biological media. Cytotoxicity and genotoxicity assays performed with HCT116 cell lines by MTT assay, oxidative stress, intracellular lipid analysis, apoptosis, and cell cycle estimation depicted cytotoxicity as a consequence of reactive oxygen species quenching and lipid accumulation, inducing significant apoptosis and genotoxic cytotoxicity. In silico analysis depicted the role of Sod1, Sod2, p53, and VLDR proteins–TiO₂ hydrogen bond interaction having a key role in determining the cytotoxicity. The particles exhibited significant antibacterial activities against Escherichia coli and Salmonella typhimurium.

Introduction: Colistin is considered to be the last resort for the management of infections caused by multi-drug resistant (MDR) gram-negative bacilli (GNB). However, in the recent past, there has been a rise in colistin resistance among MDR isolates in clinical settings with no profound data on the incidences and causes. The purpose of this study was to estimate the prevalence of colistin-resistance (CLR) in MDR isolates collected from different intensive care units (ICUs) and to determine the clinical outcomes of the patients. Materials and methods: A prospective study was conducted in the ICU of a tertiary care hospital in Eastern Odisha, India from March 2019 to February 2020. MDR GNB isolates from different clinical samples of ICU patients, not intrinsically resistant to colistin, were included in this study. Samples collected for culture and sensitivity testing were processed as per standard guidelines in the microbiology laboratory. MDR organisms were examined for colistin susceptibility by the broth dilution method. Clinical data was collected from hospital electronic medical records and presented as percentage, number (N), and median (range). Results: The prevalence of colistin resistance MDR GNB was found to be 19.6% in the present study. Colistin resistance among the MDR isolates was found to be the highest (9.2% for Klebsiella pneumonia followed by 5% for Escherichia coli). CLR drug-resistant isolates were commonly (28.8%) isolated from samples of respiratory tract infections and the majority (54.1%) were from neurology ICU. In this study, co-morbidity was not found among 57.9% of the ICU patients and recovery was maximum i.e., 74.2%. Conclusion: This study found the prevalence of colistin resistance to be high (19.6%) among all MDR GNB isolates from samples of ICU patients, Klebsiella pneumonia and Escherichia coli commonly acquire colistin resistance. Patients in the neurology ICU were frequently infected with CLR MDR strains. Most of the patients who recovered were without any underlying comorbidities. Prolonged hospital stay and direct antibiotic pressure in the hospital can lead to the development of CLR variants.

Lactobacillus strains have been shown to adhere to the mucosal components of intestinal epithelial cells. However, established in vitro adhesion assays have several drawbacks in assessing the adhesion of new Lactobacillus strains. The present study aimed to compare the adhesion of four different Lactobacillus strains and select the most adherent microbe, based on in silico approach supported by in vitro results. The mucus-binding proteins in Lactobacillus acidophilus, L. plantarum, L. brevis and L. fermentum were identified and their capacities to interact with intestinal mucin were compared by molecular docking analysis. Lactobacillus acidophilus had the maximal affinity of binding to mucin with predicted free energy of −6.066 kcal mol⁻¹. Further, in vitro experimental assay of adhesion was performed to validate the in silico results. The adhesion of L. acidophilus to mucous secreting colon epithelial HT-29 MTX cells was highest at 12%, and it formed biofilm with maximum depth (Z = 84 μm). Lactobacillus acidophilus was determined to be the most adherent strain in the study. All the Lactobacillus strains tested in this study, displayed maximum affinity of binding to MUC3 component of mucus as compared to other gastrointestinal mucins. These findings may have importance in the design of probiotics and health care management.