Green biomimetic silver nanoparticles utilizing the red algae Amphiroa rigida and its potent antibacterial, cytotoxicity and larvicidal efficiency.

The present investigation reports a simple, rapid, inexpensive, and eco-friendly approach for synthesizing Amphiroa rigida-mediated silver nanoparticles (AR-AgNPs) for the first time. The biomimetic synthesized AR-AgNPs were characterized by both spectral and microscopic analysis. The UV-visible spectrum showed the surface plasmon peak at 420 nm, which indicated the formation of AR-AgNPs. X-ray diffraction characterization of AR-AgNPs showed a face-centered cubic crystal (25 nm) and the transmission electron microscope micrograph showed spherical shape. The functional group of polysaccharide that plays a major role as a stabilizing and reducing agent is confirmed by Fourier-transform infrared spectroscopy. The biomimetic synthesized AR-AgNPs showed antibacterial activity against Staphylococcus aureus (21 ± 0.2 mm) and Pseudomonas aeruginosa (15 ± 0.2 mm). Further, the cytotoxic effects of AR-AgNPs against MCF-7 human breast cancer cells were observed through acridine orange-ethidium bromide and Hoechst staining. Besides, AR-AgNPs are found to be inhibit the growth of 3rd and 4th instar larvae of Aedes aegypti in a dose-dependent manner.

Report: In vivo anticoccidial effects of Azadirachta indica and Carica papaya L. with salinomycin drug as a dietary feed supplement in broiler chicks.

A total of thirty suspected broiler chicks were screened for coccidiosis, of them 25 chicks were found to be infected with coccidiosis viz. Eimeria tenella (15) Eimeria maxima (5) Eimeria necatrix (6) and Eimeria mitis (4). The anticoccidial efficacy of Azadirachta indica and Carica papaya with Salinomycin as a dietary feed supplement on the representative E. tenella (25 x 10³ oocyst) infection challenged in broiler chicks was studied in six groups for the period of six weeks. A. indica and C. papaya leaves were administered in powder form at the concentration of 0.1% and 0.2% respectively. The Oocysts per gram (OPG) count were observed on 8th, 9th, 10th, 11th day of post inoculation (DPI). The challenged experimental chicks revealed haemorrhage, thickening of mucosa, cores of blood and ballooning of caecum. The experimental group T5 chicks treated with A. indica were analyzed to possess the maximum weight gain (2.003), better feed conversion ratio (FCR) (2.32), OPG count (5.87), livability percentage (88) and the lesion score (3.33). Chi-square test analysis revealed no significant differences among the treated groups and the performance parameters. Therefore, this study concludes that plant sources used as a remedial curate for coccidiosis is a perforated growth in the commercial broiler industries.

Acorus calamus rhizome extract mediated biosynthesis of silver nanoparticles and their bactericidal activity against human pathogens.

Silver nanoparticle (AgNP) synthesis and characterization is an area of vast interest due to their broader application in the fields of science and technology and medicine. Plants are an attractive source for AgNP synthesis because of its ability to produce a wide range of secondary metabolites with strong reducing potentials. Thus, the present study describes the synthesis of AgNPs using aqueous rhizome extract of Acorus calamus (sweet flag). The AgNP formation was evaluated at different temperatures, incubation time and concentrations of AgNO3 using Response surface methodology based Box-Behnken design (BBD). The synthesized AgNPs were characterized by UV-Visible spectroscopy, Fourier transform infra-red spectroscopy (FTIR), X-ray diffraction (XRD), and Scanning electron microscopy-energy-dispersive spectroscopy (SEM-EDS). The surface plasmon resonance found at 420 nm confirmed the formation of AgNPs. SEM images reveal that the particles are spherical in nature. The EDS analysis of the AgNPs, using an energy range of 2-4 keV, confirmed the presence of elemental silver without any contamination. The antibacterial activity of synthesized AgNPs was evaluated against the clinical isolates Staphylococcus aureus and Escherichia coli and it was found that bacterial growth was significantly inhibited in a dose dependent manner. The results suggest that the AgNPs from rhizome extract could be used as a potential antibacterial agent for commercial application.

Biosynthesis of silver nanoparticles using Acacia leucophloea extract and their antibacterial activity.

The immense potential of nanobiotechnology makes it an intensely researched field in modern medicine. Green nanomaterial synthesis techniques for medicinal applications are desired because of their biocompatibility and lack of toxic byproducts. We report the toxic byproducts free phytosynthesis of stable silver nanoparticles (AgNPs) using the bark extract of the traditional medicinal plant Acacia leucophloea (Fabaceae). Visual observation, ultraviolet-visible spectroscopy, and transmission electron microscopy (TEM) were used to characterize the synthesized AgNPs. The visible yellow-brown color formation and surface plasmon resonance at 440 nm indicates the biosynthesis of AgNP. The TEM images show polydisperse, mostly spherical AgNP particles of 17-29 nm. Fourier transform infrared spectroscopy revealed that primary amines, aldehyde/ketone, aromatic, azo, and nitro compounds of the A. leucophloea extract may participate in the bioreduction and capping of the formed AgNPs. X-ray diffraction confirmed the crystallinity of the AgNPs. The in vitro agar well diffusion method confirmed the potential antibacterial activity of the plant extract and synthesized AgNPs against the common bacterial pathogens Staphylococcus aureus (MTCC 737), Bacillus cereus (MTCC 1272), Listeria monocytogenes (MTCC 657), and Shigella flexneri (MTCC 1475). This research combines the inherent antimicrobial activity of silver metals with the A. leucophloea extract, yielding antibacterial activity-enhanced AgNPs. This new biomimetic approach using traditional medicinal plant (A. leucophloea) barks to synthesize biocompatible antibacterial AgNPs could easily be scaled up for additional biomedical applications. These polydisperse AgNPs green-synthesized via A. leucophloea bark extract can readily be used in many applications not requiring high uniformity in particle size or shape.

Screening, phylogenetic analysis and antibiotic sensitivity pattern of Salmonella enterica serovar Typhi isolates from typhoid asymptomatic carriers

OBJECTIVE@#To isolate the Salmonella enterica serovar Typhi (S. typhi) from asymptomatic typhoid carriers in the local population. To assess the antibiotic sensitivity and resistant pattern of S. typhi isolates against viable antibiotics and phylogenetic analysis of S. typhi isolates on the basis of 16S rDNA gene.@*METHODS@#S. typhi was isolated and identified based on the cultural characteristics on BSA (Bismuth Sulphite Agar), MacConkey agar, agglutination test with specific antiserum and phylogenetic analysis. S. typhi isolates were tested for sensitivity and resistant pattern with a number of viable antibiotics by disc diffusion method.@*RESULT@#A total of 15 bile samples were collected from the food handlers to screen the typhoid asymptomatic carriers. Positive result was yielded for 3 out of 15 samples. S. typhi isolates showed resistant to amphicillin (100%), tetracyclin (100%), rifampicin (66.5%), ofloxacin (33.5%), cloxacillin (33.5%) and susceptibility to gentamycin (100%), amikacin (100%), chloramphenicol (100%), streptomycin (100%), kanamycin (100%), cprofloxacin (100%), amoxycillin (66.5%) and ofloxacin (66.5%).@*CONCLUSIONS@#This study demonstrates the outbreak of typhoid fever occurs through asymptomatic carrier. In addition, this study also reveals the occurrence of considerable drug resistant among the S. typhi isolates.

Effect of ompR gene mutation in expression of ompC and ompF of Salmonella typhi.

In the present investigation, a total of 50 stool samples were collected from the food handlers to screen the typhoid asymptomatic carriers, positive result was yielded for 2 out of the 50 samples. Salmonella typhi was isolated and identified based on the cultural characteristics on BSA, Macconkey agar, XLD and phylogenetic analysis. The ompR region of these two strains was amplified, sequenced and a Neighbor-Joining algorithm tree of ompR was constructed. The isolates were designated as (Salmonella Strain) SS-3 and SS-5 respectively. The isolates were subjected to mutation using sodium chloride at various osmolarity concentrations in LB broth. Both the wild and mutant Salmonella typhi were used for the isolation of outer membrane protein. The outer membrane protein was isolated and compared with both the wild and mutated Salmonella typhi. The expression of outer membrane protein was showing the variation in the expression which were noticed by using SDS-PAGE. On the basis of the results, it was concluded that the ompR-envZ two component regulatory systems play an important role on the regulation of Vi polysaccharide synthesis in S. typhi, and that one of the environmental signals for this regulation may be osmolarity.