Salmonella typhi Antigen Rapid Test

Carrot cellulose nano fibers (CNF) have been extracted from carrot pulp using acid hydrolysis process. The size of the CNF was in the range of 6.33-58.77 nm. Starch nano-composite films were manufactured using varying concentration of CNF (5%, 10%, 15%, 20%) and mechanical properties of the films were studied at relative humidity 50% and 75%. Nano-composite films were manufactured using Eucalyptus globulus leafs extract (1%, 2%, 3%, 4%). Physio-chemical properties, antioxidant, antimicrobial, morphological and crystalline properties of the films were studied. Nano-composite films with 4% Eucalyptus globulus leafs extract was best to provide better barrier, antioxidant properties to grapes when wrapped and stored at room temperature (25 +/- 2)degrees C for 7 days and refrigerator temperature (4 +/- 1)degrees C for 28 days. Wrapped grapes with NCC/Eucalyptus globulus leaf extract stored for 28 days either at 25 degrees C or 4 degrees C had bacterial surface loads reduced up to 5 orders of magnitude compared to non-wrapped samples and had 4 orders of magnitude less bacterial surface loads than at the beginning of the experiments. Wrapped grapes with NCC/Eucalyptus globulus leaf extract significantly reduced the growth of Escherichia coli, Listeria monocytogenes, Salmonella typhimurium and Penicillium spp. when the cells of these organisms were spiked onto grapes and the samples were stored either at (25 +/- 2) degrees C or (4 +/- 1) degrees C for 28 days. The results showed that nano-composite with 4% Eucalyptus globulus leafs extract films have immense potential as food packaging/wrapping material.

In Gram-negative bacteria, the folding and insertion of beta-barrel outer membrane proteins (OMPs) to the outer membrane are mediated by the beta-barrel assembly machinery (BAM) complex. Two leading models of this process have been put forth: the hybrid barrel model, which claims that a lateral gate in BamA's beta-barrel can serve as a template for incoming OMPs, and the passive model, which claims that a thinned membrane near the lateral gate of BamA accelerates spontaneous OMP insertion. To examine the key elements of these two models, we have carried out 45.5 mu s of equilibrium molecular dynamics simulations of BamA with and without POTRA domains from Escherichia coli, Salmonella enterica, Haemophilus ducreyi and Neisseria gonorrhoeae, together with BamA's homolog, TamA from E. coli, in their native, species-specific outer membranes. In these equilibrium simulations, we consistently observe membrane thinning near the lateral gate for all proteins. We also see occasional spontaneous lateral gate opening and sliding of the beta-strands at the gate interface for N. gonorrhoeae, indicating that the gate is dynamic. An additional 14 mu s of free-energy calculations shows that the energy necessary to open the lateral gate in BamA/TamA varies by species, but is always lower than the Omp85 homolog, FhaC. Our combined results suggest OMP insertion utilizes aspects of both the hybrid barrel and passive models. Author summary Gram-negative bacteria such as Escherichia coli have a second, outer membrane surrounding them. This outer membrane provides an additional layer of protection, but also presents an additional challenge in its construction, exacerbated by the lack of chemical energy in this region of the bacterial cell. For example, proteins in the outer membrane are inserted via BamA, itself an integral membrane protein. The precise mechanism by which BamA assists in the insertion process are still unclear. Here, we use extensive simulations in atomistic detail of BamA from multiple species in its native outer membrane environment to shed light on this process. We find that the lateral gate of BamA, a proposed pathway into the membrane, is dynamic, although to a degree varying by species. On the other hand, thinning of the outer membrane near BamA's lateral gate is observed consistently across all simulations. We conclude that multiple features of BamA contribute to protein insertion into the outer membrane.