Possible Effect of Antibiotic-Supplemented Feed and Environment on the Occurrence of Multiple Antibiotic Resistant Escherichia coli in Chickens

The purpose of this study was to determine the occurrence of antibiotic resistant Escherichia coli isolated from chicks and chickens. This study was carried out on three flocks of birds fed commercial feeds supplemented with antibiotics from three commercial farms. The chicks and chickens in the fourth flock were reared in a chicken house, given feed without antibiotic supplementation. Cloacal swabs were taken from 50 birds per flock at 1, 21 and 42-day old. A total of 507 E. coli were isolated from these birds. The resistance of E. coli isolated form 1-day-old chicks to chloramphenicol (10 μg), cephalothin (30 μg), cephalaxin (30 μg), enrofloxacin (5 μg) and neomycin (30 μg) was 0-45% compared to the other four antibiotics, nalidixic acid (30 μg), streptomycin (10 μg), tetracycline (30 μg) and trimethoprim (5 μg) which was 75-100%. The rates of resistance to antibiotics increased with the age of the chicks. Most of the isolates were resistant to at least 6 to 7 antibiotics. The highest rates of resistance to antibiotics were seen in 21 and 42 day old chickens. Escherichia coli, Klebsiella and Pseudomonas sp. isolated from feed samples were resistant to 4-9 antibiotics. The study suggests that the colonization antibiotic-resistant E. coli in the intestinal tracts of chicks and chickens were not necessarily due to the use of antibiotics in the feed as supplementation but may also be acquired from the immediate “contaminated” environment

Characterizing Protein-Protein Interactions with the Fragment Molecular Orbital Method

Proteins are vital components of living systems, serving as building blocks, molecular machines, enzymes, receptors, ion channels, sensors, and transporters. Protein-protein interactions (PPIs) are a key part of their function. There are more than 645,000 reported disease-relevant PPIs in the human interactome, but drugs have been developed for only 2% of these targets. The advances in PPI-focused drug discovery are highly dependent on the availability of structural data and accurate computational tools for analysis of this data. Quantum mechanical approaches are often too expensive computationally, but the fragment molecular orbital (FMO) method offers an excellent solution that combines accuracy, speed and the ability to reveal key interactions that would otherwise be hard to detect. FMO provides essential information for PPI drug discovery, namely, identification of key interactions formed between residues of two proteins, including their strength (in kcal/mol) and their chemical nature (electrostatic or hydrophobic). In this chapter, we have demonstrated how three different FMO-based approaches (pair interaction energy analysis (PIE analysis), subsystem analysis (SA) and analysis of protein residue networks (PRNs)) have been applied to study PPI in three protein-protein complexes

Thixotropic Red Microalgae Sulfated Polysaccharide-Peptide Composite Hydrogels as Scaffolds for Tissue Engineering

Sulfated polysaccharides of red marine microalgae have recently gained much attention for biomedical applications due to their anti-inflammatory and antioxidant properties. However, their low mechanical properties limit their use in tissue engineering. Herein, to enhance the mechanical properties of the sulfated polysaccharide produced by the red marine microalga, Porphyridium sp. (PS), it was integrated with the fluorenylmethoxycarbonyl diphenylalanine (FmocFF) peptide hydrogelator. Transparent, stable hydrogels were formed when mixing the two components at a 1:1 ratio in three different concentrations. Electron microscopy showed that all hydrogels exhibited a nanofibrous structure, mimicking the extracellular matrix. Furthermore, the hydrogels were injectable, and tunable mechanical properties were obtained by changing the hydrogel concentration. The composite hydrogels allowed the sustained release of curcumin which was controlled by the change in the hydrogel concentration. Finally, the hydrogels supported MC3T3-E1 preosteoblasts viability and calcium deposition. The synergy between the sulfated polysaccharide, with its unique bioactivities, and FmocFF peptide, with its structural and mechanical properties, bears a promising potential for developing novel tunable scaffolds for tissue engineering that may allow cell differentiation into various lineages

ALICE A Large Ion Collider Experiment

POLAR-2 is a follow-up GRB mission of POLAR, which has observed low levels of polarization degree and a temporal evolution of the polarization angle, indicating that time resolved studies of $\gamma$ photons polarization are required to constrain theoretical emission models of GRB’s. POLAR-2 detector aim to put in space a detector with one order of magnitude sensitivity improvement versus POLAR. POLAR-2 will be the most sensitive GRB detector covering half of the sky. The instrument, proposed by an international collaboration, was selected to be launched in 2024 to the China Space Station and operate for at least 2 years. POLAR-2 will use same plastic bar concept then POLAR but will be readout by SiPMT. The payload will also feature a spectrometer. The instrument is foreseen to perform detailed polarization measurements of at least 100 GRBs