Gallium-Curcumin Nanoparticle Conjugates as an Antibacterial Agent against Pseudomonas aeruginosa: Synthesis and Characterization.

Combating antibiotic resistance has found great interest in the current clinical scenario. Pseudomonas aeruginosa, an opportunistic multidrug-resistant pathogen, is well known for its deadly role in hospital-acquired infections. Infections by P. aeruginosa are among the toughest to treat because of its intrinsic and acquired resistance to antibiotics. In this study, we project gallium-curcumin nanoparticle (GaCurNP) conjugates as a prospective candidate to fight against P. aeruginosa. The synthesized GaCurNPs were spherical with an average size ranging from 25-35 nm. Analysis by Fourier transform infrared (FT-IR) spectroscopy, Raman spectroscopy, and X-ray photoelectron spectroscopy deduced the nature of interaction between gallium and curcumin. Conjugate formation with gallium was found to improve the stability of curcumin at the physiological pH. When tested after 24 h of contact, at the physiological pH and 37 °C, the degradation of curcumin bound in the GaCurNPs was 26%, while that of native curcumin was 95%. The minimum inhibitory concentration (MIC) of GaCurNPs was found to be 82.75 µg/mL for P. aeruginosa (ATCC 27853). GaCurNPs also showed excellent biofilm inhibition at 4MIC concentration. Raman spectroscopic analysis showed that GaCurNPs are capable of disrupting the cells of P. aeruginosa within 3 h of contact. Live/dead imaging also confirmed the compromised membrane integrity in cells treated with GaCurNPs. Scanning electron microscopy analysis showed membrane lysis and cell structure damage. The AlamarBlue assay showed that when L929 cell lines were treated with GaCurNPs with concentrations as high as 350 µg/mL, the cell viability elicited by the nanoparticles was 70.89%, indicating its noncytotoxic nature. In short, GaCurNPs appear to be a promising antibacterial agent capable of fighting a clinically significant pathogen, P. aeruginosa.

Evaluation of diagnostic accuracy of developed rapid SARS-COV-2 IgG antibody test kit using novel diluent system.

Immunochromatographic assay kits are used in primary diagnostics which is based on the principle of antigen and antibody interaction. These kits play pivotal role in rapid surveillance of infectious diseases at early stages as well as for the surveillance of the contagious diseases. The immunochromatographic test kits lacks sensitivity and specificity with certain diseases. In this study, our intention was to develop a rapid test kit for SARS-COV-2 with a novel diluent system to enhance the efficacy of antigen-antibody binding and thereby the improvement in the sensitivity outlined. Finally, IgG antibodies against SARS-COV-2 virus peptides were analyzed using 25 positive and 25 negative confirmed clinical samples. The sensitivity of the clinical studies showed 91% sensitivity and 100% specificity. Therefore, the authors propose that this assay will be a potential tool for efficient community or sentinel surveillance of SARS-COV-2 infection and additionally, for effective monitoring of convalescent sera therapy.

Diagnosis of tuberculous meningitis: Current scenario from a Tertiary Neurocare Centre in India.

BACKGROUND: Tuberculous meningitis (TBM) is a condition that is caused by Mycobacterium tuberculosis complex and is difficult to diagnose due to the nonspecificity of the presentations. The study analyzed the different modes of diagnosis available in a developing country set up over a period of five years to understand the diagnostic values of the current conventional and automated methods of diagnosis of TBM among the patients suspected with chronic meningitis. METHODS: A total of 10,281 cerebrospinal fluid samples (CSF) were collected from suspected chronic meningitis patients, of which 790 samples were from individuals who had clinically suspected TBM. The samples were subjected to CSF cytology and staining, culturing, immunological tests, molecular techniques, and methods for detection of drug resistance. RESULTS: The TBM patients were predominantly male, with a mean age of 21-40 years. CSF pleocytosis and lymphocytic predominance were noted. Culture had 40.13% positivity among clinically suspected TBM patients. The multidrug-resistant M. tuberculosis (MDR-TB) constituted 3.14% of the total clinical isolates. With IS6110 PCR, a specificity of 92.86% and sensitivity of 100% are seen with an assay threshold of 30pg/ml. Line probe assay (LPA) using culture isolates had a sensitivity of 97.67% and a specificity of 100%. Direct CSF LPA showed a sensitivity of 96.15% and a specificity of 100%. CONCLUSIONS: A combination of techniques that involved culture, cytology, and DNA amplification methods was found to be promising in specific, accurate, and rapid detection of M. tuberculosis in the CSF samples from patients.

Proteogenomic analysis of pathogenic yeast Cryptococcus neoformans using high resolution mass spectrometry.

BACKGROUND: Cryptococcus neoformans, a basidiomycetous fungus of universal occurrence, is a significant opportunistic human pathogen causing meningitis. Owing to an increase in the number of immunosuppressed individuals along with emergence of drug-resistant strains, C. neoformans is gaining importance as a pathogen. Although, whole genome sequencing of three varieties of C. neoformans has been completed recently, no global proteomic studies have yet been reported. RESULTS: We performed a comprehensive proteomic analysis of C. neoformans var. grubii (Serotype A), which is the most virulent variety, in order to provide protein-level evidence for computationally predicted gene models and to refine the existing annotations. We confirmed the protein-coding potential of 3,674 genes from a total of 6,980 predicted protein-coding genes. We also identified 4 novel genes and corrected 104 predicted gene models. In addition, our studies led to the correction of translational start site, splice junctions and reading frame used for translation in a number of proteins. Finally, we validated a subset of our novel findings by RT-PCR and sequencing. CONCLUSIONS: Proteogenomic investigation described here facilitated the validation and refinement of computationally derived gene models in the intron-rich genome of C. neoformans, an important fungal pathogen in humans.

Phosphoproteome of Cryptococcus neoformans.

Cryptococcus neoformans is an encapsulated pathogenic yeast, which causes life threatening meningitis in immunocompromised individuals. C. neoformans var. grubii is the most prevalent and virulent form among the two varieties of C. neoformans - C. neoformans var. grubii and C. neoformans var. neoformans. The virulence of C. neoformans is mainly conferred by its capsule and melanin. cAMP dependent PKA-induced phosphorylation events are reported to be associated with the expression of these virulence traits, which highlights the importance of phosphoproteins in virulence and infection. Therefore, we performed global profiling of phosphoproteome of C. neoformans to enable a better understanding of molecular regulation of its virulence and pathogenesis. High resolution mass spectrometry of TiO2 enriched phosphopeptides from C. neoformans var. grubii grown in culture led to the identification of 1089 phosphopeptides derived from 648 proteins including about 45 kinases. Motif enrichment analysis revealed that most CDK family substrates were found to be phosphorylated. This indicates that cyclin-dependent kinases were among the active kinases in the pathogen in culture. These studies provide a framework for understanding virulence mechanisms in the context of signalling pathways in pathogenic yeast. This article is part of a Special Issue entitled: Trends in Microbial Proteomics. BIOLOGICAL SIGNIFICANCE: C. neoformans is a pathogenic yeast responsible for cryptococcal meningitis. Melanin and polysaccharide capsule have been established as some of the key virulence factors that play a major role in the pathogenesis of C. neoformans. Recent studies have shown the role of kinase mediated signalling pathways in governing biosynthesis of these virulence factors. This study revealed 1540 phosphorylation sites in 648 proteins providing a comprehensive view of phosphoproteins in C. neoformans. This should serve as a useful resource to explore activated signalling pathways in C. neoformans and their association with its virulence and pathogenesis.