Enteroaggregative Escherichia coli (EAEC) has been widely recognized as one of the leading causes of infantile diarrhoea and nutrient malabsorption in developing as well as developed countries. In recent years, drug resistance, particularly multi-drug resistance (MDR), among the EAEC strains has been widely documented and could result in a therapeutic stumble. Antimicrobial alternatives are widely employed to curb this emerging public health crisis. In the present study, a facile one-pot synthesis of silver/zinc oxide nanocomposites (Ag/ZnO NCs) using a methanolic extract of stem and leaves of Curcuma longa was performed. The synthesis of Ag/ZnO NCs was confirmed using UV-vis spectroscopy and Fourier transform infrared spectroscopy, while the thermal stability was ascertained by thermogravimetric analysis with differential thermogravimetric analyses, and crystallinity was determined using powder X-ray diffraction. The shape and size of the green synthesized Ag/ZnO NCs, determined using field-emission–scanning-electron microscopy and transmission electron microscopy, revealed an irregular polycrystalline morphology with a size of 31.34 ± 1.27 nm. Later, the antibacterial potential of the green synthesized Ag/ZnO NCs evaluated against MDR- EAEC strains revealed a minimum inhibitory concentration of 31.25 μg/mL and a minimum bactericidal concentration ranging from 62.50 to 125 μg/mL. Moreover, the green synthesized Ag/ZnO NCs inhibited the biofilm-forming ability of the tested strains of MDR-EAEC. Furthermore, concentration-dependent antioxidant activity was exhibited by the green synthesized Ag/ZnO NCs, as evidenced by the ABTS assay and reducing power assay. Overall, this study demonstrated the antibacterial potential of Ag/ZnO NCs synthesized using C. longa extracts with antifouling as well as antioxidant properties, which could be used as an alternative therapeutic candidate.

Enteroaggregative Escherichia coli (EAEC) is a neglected, though emerging, bacterial pathogen associated with gastrointestinal illnesses worldwide. Recently, a surprising surge in the multi-drug resistance pattern among EAEC strains has been observed on a global scale; hence, emphasis has been given to adjuvant therapies to combat this nagging public health threat. This study assessed the antibacterial efficacy of ZnO NPs synthesised using the aqueous extract of Piper longum catkin against multi-drug resistant (MDR) strains of EAEC. Initially, the synthesis of ZnO NPs was confirmed via UV-Vis spectroscopy and Fourier transform infra-red spectroscopy (FTIR) analysis. The thermal stability of ZnO NPs was evidenced by TGA/DTA, while PXRD analysis revealed a hexagonal wurtzite crystalline structure, which was then confirmed by electron microscopy. The minimum inhibitory concentration and minimum bactericidal concentration of the bio-fabricated ZnO NPs, determined via microbroth dilution technique against MDR-EAEC (n = 3) strains, was revealed to be 125 μg/mL and 250 μg/mL, respectively. In addition, the ZnO NPs were found to be variably stable and safe. The green synthesised ZnO NPs exhibited a concentration-dependent antioxidant activity and inhibited the biofilm forming ability of the tested MDR-EAEC strains. Overall, this study revealed an eco-friendly one-pot synthesis of ZnO NPs, which could be used as a fruitful antimicrobial substitute against MDR-EAEC strains.

Egg yolk represents an alternate source of antibody and provides some advantages over mammalian serum immunoglobulins. The principal immunoglobulin in avian blood is Immunoglobulin Y (IgY) and is transferred to egg yolk and then to their offspring and thus makes it possible for the non-invasive harvesting of antibodies in higher amount from eggs. Moreover, due to the structural differences and phylogenetic variations, IgY is more acceptable than mammalian antibodies for diagnostic purposes, as it does not interfere with mammalian antibodies and shows greater avidity for proteins retained in mammals. As a therapeutic and diagnostic tool, IgY has wide application in animal and human health. The emergence of drug resistance organisms causing respiratory tract infections is a critical problem for the health care system worldwide. Passive immunization is a potential alternative for this. Recent studies on the diagnosis and therapeutic effects of IgY against SARS-CoV-2 indicates the importance of this technique in the present context. This review refers to the use of IgY antibodies from chicken egg yolks against the infection caused by bacteria, viruses (including SARS-CoV-2) and parasites in human beings and in animals in addition to its use in food preservation, anti tumour and anti allergic activities. Keywords: Egg yolk antibodies (IgY); human health; SARS-CoV-2; Egg yolk