ABSTRACT
Purpose: To study the clinical presentation, mycological profile, and risk factors of fungal keratitis (FK) cases presenting at two tertiary?care centers, one each at North (Chandigarh) and Northeast (Assam) India, and to compare the spectrum of fungi recovered from the clinical and environmental samples at both locations. Methods: All patients with suspected FK were enrolled from both the centers between January 2018 and December 2019. Corneal samples were collected and processed as per standard laboratory protocols. Demographic details and clinical and mycological profiles were noted in all patients. Environmental sampling from the soil, air, and the vegetative matter was performed from both locations and neighboring districts. Results: Of the 475 suspected cases, 337 (71%) were diagnosed as FK (median age: 50 years; 77.2% males). The presence of diabetes, hypertension, blurred vision, and corneal discoloration was significantly higher in patients with FK compared to those without FK. Aspergillus sp. (52.1%) and Fusarium sp. (47.61%) were the predominant etiological agents isolated from cases in North and Northeast India, respectively. FK due to melanized fungi was associated with diabetes, trauma with animal tail, and corneal discoloration. A similar spectrum of fungi was seen in environmental and clinical samples in both the regions. Conclusion: The difference in etiological agents of FK and environmental fungal isolates in North and Northeast India highlights the need to identify the ecological niche of potential fungal pathogens. Prospective, multicenter studies, systematic environmental sampling, and the evaluation of the differences in causative agents and clinical presentation of FK from different parts of the country can substantially improve our understanding of its region?specific clinico?epidemiological profile.
ABSTRACT
Green synthesis of silver nanoparticles (AgNPs) has garnered tremendous interest as conventional methods include the use and production of toxic chemicals,products,by-products and reagents.In this regard,the synthesis of AgNPs using green tea (GT) extract and two of its components,(-)-epi-gallocatechin gallate (EGCG) and (+)-catechin (Ct) as capping/stabilizing agents,is reported.The syn-thesized AgNPs showed antibacterial activity against the bacterial strains Staphylococcus aureus and Escherichia coli,along with anticancer activity against HeLa cells.After administering nanoparticles to the body,they come in contact with proteins and results in the formation of a protein corona;hence we studied the interactions of these biocompatible AgNPs with hen egg white lysozyme (HEWL) as a carrier protein.Static quenching mechanism was accountable for the quenching of HEWL fluorescence by the AgNPs.The binding constant (Kb) was found to be higher for EGCG-AgNPs ((2.309 ± 0.018) × 104 M-1)than for GT-AgNPs and Ct-AgNPs towards HEWL.EGCG-AgNPs increased the polarity near the binding site while Ct-AgNPs caused the opposite effect,but GT-AgNPs had no such observable effects.Circular dichroism studies indicated that the AgNPs had no such appreciable impact on the secondary structure of HEWL.The key findings of this research included the synthesis of AgNPs using GT extract and its con-stituent polyphenols,and showed significant antibacterial,anticancer and protein-binding properties.The-OH groups of the polyphenols drive the in situ capping/stabilization of the AgNPs during synthesis,which might offer new opportunities having implications for nanomedicine and nanodiagnostics.