One pot fabrication of diamino naphthalene -AuNPs decorated graphene nanoplatform for the MRSA detection in the biological sample.

Early monitoring of MRSA can effectively mitigate the disease risk by using Penicillin-binding protein 2a (PbP2a) biomarker. Diamino naphthalene-AuNPs decorated graphene (AuNPsGO-DN) nanocomposite was synthesized for a rapid and sensitive immunosensor detecting PbP2a. The synthesized AuNPsGO-DN nanocomposites were characterized by field emission scanning electron microscopy (FE-SEM), energy-dispersive X-ray spectroscopy (SEM-EDX), Fourier transform infrared spectroscopy (FT-IR), Raman spectroscopy, and X-ray diffraction spectroscopy (XRD). Electrochemical characterization done with cyclic voltammetry (CV), differential pulse voltammetry (DPV), and electrical impedance spectroscopy (EIS) techniques. Anti-PbP2a monoclonal antibodies immobilized at AuNPsGO-DN/GCE via covalent bonding. AuNPs enhanced the electrode surface area and the antibodies' loading. Mercaptopropionic acid (MPA) was a linker between the AuNPs and antibodies, orientated the antibodies as opposite to the PbP2a antigen, and improved the sensitivity and specificity. The antiPbP2a/MPA/AuNPsGO-DN/GCE electrode displayed sensitive and selective detection towards the PbP2a antigen in phosphate buffer saline (PBS pH 7.4). The broad linear range from 0.01 to 8000 pg/mL was obtained with LOD of 0.154 pg/mL and 0.0239 pg/mL, respectively. A label-free, simple, and sensitive immunosensor was developed with a 98-106 % recovery rate in spiked biological samples. It shows the potential applicability of the developed immunoelectrode.

Rapid and label-free A2 peptide epitope decorated CoFe2O4-C60 nanocomposite-based electrochemical immunosensor for detecting Visceral Leishmaniasis.

Diagnosis of Visceral Leishmaniasis is challenging due to the shared clinical features with malaria, typhoid, and tuberculosis. A CoFe2O4-C60 nanocomposite-based immunosensor decorated with a sensitive A2 peptide antigen was fabricated to detect anti-A2 antibodies for application in visceral leishmaniasis diagnosis. The flame-synthesised nanocomposite was characterised using Fourier Transform Infrared spectroscopy (FTIR), X-ray diffraction spectroscopy (XRD), Scanning electron microscopy (SEM), Energy dispersive X-ray spectroscopy (EDX), Raman spectroscopy and electrochemical impedance spectroscopy (EIS) techniques. N terminated specific A2 peptide epitope antigen (NH2-QSVGPLSVGP-OH) was synthesised and characterised by high-performance liquid chromatography (HPLC) and liquid chromatography-mass spectroscopy (LC-MS). Using EDC/NHS, A2 peptide antigen (Apg) was immobilised on the CoFe2O4-C60-modified electrode. The performance of the immunosensor, Apg-CoFe2O4-C60NP/GCE, was evaluated by testing its ability to detect varying concentrations of anti-A2 antibody solution in PBS and spiked serum with 1 mM [Fe(CN)6]3-/4- in 0.01 M PBS (pH 7.4) as supporting electrolyte. using differential pulse voltammetry. The immunosensor showed excellent reproducibility and a linear range of 10-10-10-1 µg/mL, with an experimental detection limit of 30.34 fg/mL. These results suggest that the fabricated sensor has great potential as a tool for diagnosing visceral leishmaniasis.

Isoflavonoid and Furanochromone Natural Products as Potential DNA Gyrase Inhibitors: Computational, Spectral, and Antimycobacterial Studies.

In pursuit of new antitubercular agents, we here report the antimycobacterial (H37Rv) and DNA gyrase inhibitory potential of daidzein and khellin natural products (NPs). We procured a total of 16 NPs based on their pharmacophoric similarities with known antimycobacterial compounds. The H37Rv strain of M. tuberculosis was found to be susceptible to only two out of the 16 NPs procured; specifically, daidzein and khellin each exhibited an MIC of 25 µg/mL. Moreover, daidzein and khellin inhibited the DNA gyrase enzyme with IC50 values of 0.042 and 0.822 µg/mL, respectively, compared to ciprofloxacin with an IC50 value of 0.018 µg/mL. Daidzein and khellin were found to have lower toxicity toward the vero cell line, with IC50 values of 160.81 and 300.23 µg/mL, respectively. Further, molecular docking study and MD simulation of daidzein indicated that it remained stable inside the cavity of DNA GyrB domain for 100 ns.

Prevalence, Antibiogram and Molecular Characterization of Comunity-Acquired Methicillin-Resistant Staphylococcus Aureus in AWKA, Anambra Nigeria.

OBJECTIVES: This study evaluated the prevalence, antibiogram and molecular features of CA-MRSA in Awka, Nigeria. METHODS: Confirmation of MRSA was done by testing resistance to oxacillin (1µg), cloxacillin (5µg) and cefoxitin (30µg) on sterile Mueller Hinton agar supplemented with 4% sodium chloride. The MRSA strains were subjected to antimicrobial susceptibility testing using Kirby-Bauer disc diffusion method. Minimum inhibitory concentration was determined using agar dilution method. Penicillin binding protein 2a was detected through rapid latex agglutination assay while mecA gene was detected by polymerase chain reaction. A total of 142 S. aureus isolates were obtained from 261 samples sourced from Staff, students and fomites of the Faculty of Pharmaceutical Sciences. RESULT: The overall prevalence of MRSA was 22.6%. The carriage rate was higher in females (56.5%) than male (43.5%) and was highest in individuals of 20-30 years of age (57.65%). The MIC of the oxacillin sodium salt ranged from 4-32 µg/ml. The multi-antibiotic resistance indices show that 53.4% had Multiple Antibiotic Resistance Indexing (MARI) higher than 0.2. Penicillin binding protein 2a was detected in 8.4% of MRSA isolates, all from nasal carriage while mecA gene was detected in 5 of isolates. CONCLUSION: This study showed a very high prevalence of MRSA carriage among studied subjects.