Assessment of minimum inhibitory concentration to vancomycin, tigecycline, linezolid, daptomycin, ceftaroline and mupirocin against methicillin resistant Staphylococcus aureus clinical isolates by antibiotic gradient strips

Background: Staphylococcus aureus infections are one of the most common and serious hospital-acquired infections seen in developing countries. Methicillin resistant Staphylococcus aureus (MRSA) is an important human pathogen and normally colonized in body parts including skin, nose, perineum and throat. MRSA is resistant not only to all β-lactam groups but also other antibiotics including aminoglycosides, tetracycline and macrolides. In the present study the efficacy of agents used in the management of MRSA infections was determined by antibiotic gradient testing. Methods: A total of 60 clinical isolates of MRSA strains were collected from various diagnostic labs in central Kerala. Clinical isolates were reconfirmed as MRSA by gram staining, yellow-coloured colonies on mannitol salt Agar (MSA). Antibiotic susceptibility testing was done by disc diffusion method as recommended by CLSI guidelines. S. aureus isolates resistant to cefoxitin (30 µg) was identified as MRSA. Antibiotic gradient testing was performed to determine the MIC of vancomycin, tigecycline, linezolid, daptomycin, ceftaroline and mupirocin against MRSA isolates. Results: All the 60 MRSA isolates tested were sensitive to vancomycin, tigecycline, linezolid, daptomycin, ceftaroline and mupirocin (100%) and none of the MRSA isolates show resistance.  Conclusions: Results of present study indicates that these agents may be used alongside vancomycin in management of infection caused by MRSA

Synthesis and Thermal Characterization of Lanthanide(III) Complexes with Mercaptosuccinic Acid and Hydrazine as Ligands

Reaction of hydrazine and mercaptosuccinic acid with metal ions forms complexes with general formula [Ln(N2H4)2CH2(COO)CH(SH)(COO)1.5]·(H2O), where Ln = La(III), Pr(III), Nd(III), Sm(III), and Gd(III) at pH 5. The complexes have been characterized by elemental analysis, IR and UV-visible spectroscopic, thermal and X-ray diffraction studies. The IR data reveal that the acid moiety in the complexes is present as dianion due to the deprotonation of COOH groups by lanthanides in these complexes, leaving –SH group unionized and hydrazine as bidental neutral ligand showing absorptions in the range of 945–948 cm−1. The thermoanalytical data evince that the complexes are stable up to 103°C and undergo complete decomposition in the range of 550–594°C resulting in metal oxides. SEM images of La2O3 and Gd2O3 residues show their nano sized clusters suggesting that the complexes may be used as precursors for nano La2O3 and Gd2O3, respectively. X-ray powder diffraction patterns show isomorphism among the complexes. The kinetic parameters of the decomposition of the complexes have been computed by Coats-Redfern equation

Structural compromise of disallowed conformations in peptide and protein structures

Using a data set of 454 crystal structures of peptides and 80 crystal structures of non-homologous proteins solved at ultra high resolution of 1.2 Å or better we have analyzed the occurrence of disallowed Ramachandran (φ, ψ) angles. Out of 1492 and 13508 non-glycyl residues in peptides and proteins respectively 12 and 76 residues in the two datasets adopt clearly disallowed combinations of Ramachandran angles. These examples include a number of conformational points which are far away from any of the allowed regions in the Ramachandran map. According to the Ramachandran map a given (φ, ψ) combination is considered disallowed when two non-bonded atoms in a system of two-linked peptide units with ideal geometry are prohibitively proximal in space. However, analysis of the disallowed conformations in peptide and protein structures reveals that none of the observations of disallowed conformations in the crystal structures correspond to a short contact between non-bonded atoms. A further analysis of deviations of bond lengths and angles, from the ideal peptide geometry, at the residue positions of disallowed conformations in the crystal structures suggest that individual bond lengths and angles are all within acceptable limits. Thus, it appears that the rare tolerance of disallowed conformations is possible by gentle and acceptable deviations in a number of bond lengths and angles, from ideal geometry, over a series of bonds resulting in a net gross effect of acceptable non-bonded inter-atomic distances

Structural compromise of disallowed conformations in Peptide and protein structures

Using a data set of 454 crystal structures of peptides and 80 crystal structures of non-homologous proteins solved at ultra high resolution of 1.2 \AA or better we have analyzed the occurrence of disallowed Ramachandran (\Phi, \Psi) angles. Out of 1492 and 13508 non-glycyl residues in peptides and proteins respectively 12 and 76 residues in the two datasets adopt clearly disallowed combinations of Ramachandran angles. These examples include a number of conformational points which are far away from any of the allowed regions in the Ramachandran map. According to the Ramachandran map a given (\Phi, \Psi) combination is considered disallowed when two non-bonded atoms in a system of two-linked peptide units with ideal geometry are prohibitively proximal in space. However, analysis of the disallowed conformations in peptide and protein structures reveals that none of the observations of disallowed conformations in the crystal structures correspond to a short contact between non-bonded atoms. A further analysis of deviations of bond lengths and angles, from the ideal peptide geometry, at the residue positions of disallowed conformations in the crystal structures suggest that individual bond lengths and angles are all within acceptable limits. Thus, it appears that the rare tolerance of disallowed conformations is possible by gentle and acceptable deviations in a number of bond lengths and angles, from ideal geometry, over a series of bonds resulting in a net gross effect of acceptable non-bonded inter-atomic distances

IoT Based Supervisory and Diagnosis System for Solar Farm

Simple gadgets in the physical world are controlled over the internet by Internet of Things (IoT). To manage our gadgets remotely in integration with the already available internet infrastructure, chance for the natural linking of physical devices internationally in a personal computer, gains performance, perfection and cost benefits beyond the limited transcend manual involvement. This generation has more implementations such as microgrids, solar hamlets, solar metropolis, solar lamps. Renewable energy sources have grown quicker than at any moment in the old days of this era. The recommended device mentions an online visualization of the use of solar power as sustainable energy. Supervision is done by the Arduino Nano microcontroller with Sim800l. Smart Supervision shows the day-to-day consumption of sustainable energy via the Android app. This assists the user to analyze energy consumption and alerts the user in case of failure. The rating affects the consumption of renewable energy and energy problems

Fuzzy Based Landsman Converter For Pumping Application

Fuzzy controlled landsman converter employed for pumping application is presented here. Landsman converter(LC) is designed using voltage multiplier cell which makes the converter from reduced switching voltages. The controller is designed with Fuzzy logic to derive constant voltage output irrespective of variation of input of the converter. The input to the converter is fed from solar panel(250W). The DC output voltage of converter is fed to the electrical machine to run for different pumping applications. The design of controller and converter is analyzed using MATLAB