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Emergence of multidrug resistant strains has created serious problem for safe eradication of Staphylococcus aureus infections. Therefore, there is an urgent need to develop novel antibacterial agents to control this pathogen. Bacteriophages kill bacteria irrespective of their antibiotic sensitivity and thus they can be used as potent prophylactic/therapeutic agent to treat such infections. Here, we report isolation of broad host range anti-staphylococcal lytic bacteriophage P-27/HP from sewage water. This phage was able to inhibit 17 of 28 (60%) human disease associated S. aureus isolates. In vitro studies revealed its strong lytic efficacy to diminish S. aureus 27/HP population (c.f.u.) by more than 5.0 logs (P < 0.0001) (equivalent to 99.99%) in 3 h at 0.01 MOI. In vivo lytic efficacy analysis showed that a single subcutaneous injection of phage P-27/HP (10(7) p.f.u.) was sufficient to protect S. aureus 27/HP infected (5 × 10(8) c.f.u.) mice from bacteremia and subsequent death. A considerable decline of more than 6 logs (99.9%) in splenic S. aureus 27/HP c.f.u. count was noted at the 3 days of phage treatment. In conclusion, our results suggest that phage P-27/HP is polyvalent in nature and has high-lytic potential towards S. aureus, thus, a therapy employing this phage would be efficacious to control S. aureus infections.

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In this paper, a generalized multiband hysteresis modulation and its characterization have been proposed for the sliding-mode control of cascaded H-bridge multilevel-inverter (CHBMLI)-controlled systems. A frequency-domain method is proposed for the determination of net hysteresis bandwidth for a given desired maximum switching frequency of the inverter. The switching transition concept of Tsypkin's method and the describing function of nonlinear relay have been used for the derivation of results. A hierarchical switching algorithm has been suggested for the modular cells of the cascaded multilevel inverter. The hierarchy of each cell is swapped sequentially to provide the self-balancing capability in case the dc-link voltage is supported by the capacitors. The simulation and experimental verification of the derived results are provided through a single-phase distribution static compensator (DSTATCOM) model. The application in the three-phase system has been shown through simulation studies on a 3.3-kV distribution-system compensation using DSTATCOM. Verification on both single-and three-phase systems is obtained using a five-level cascaded-multilevel-inverter topology.Index Terms-Cascaded H-bridge multilevel inverter (CHBMLI), distribution static compensator (DSTATCOM), multiband hysteresis modulation, switching characterization.

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The aim of this study is to develop a research platform for rapid prototyping of the power electronics converters for solar photovoltaic (PV) system applications. This study describes the field-programmable gate array (FPGA)-based hardware-inthe-loop (HIL) simulation of voltage source inverter (VSI) used for PV system power conversion. The PV system and inverter models are realised in simulation as part of the HIL to test the real-time functionality of the FPGA controller. The generation of switching control signals for the VSI and its interface with the PV system is developed through the Xilinx System Generator (XSG) domain. The XSG automatically generates the VHSIC hardware description language (VHDL) code using hardware description language co-simulation for generation of gating signal for modulation of the VSI. To validate the proposed approach, the sinusoidal pulse-width modulation using bipolar and unipolar switching schemes and current control method have been tested for the PV supported VSI. The proposed approach of the rapid prototype model has been designed and implemented in the laboratory through XSG and MATLAB/SIMULINK interface. Performance comparison between the software simulation and real-time HIL simulation has been demonstrated.