Anti-bacterial activity of inorganic nanomaterials and their antimicrobial peptide conjugates against resistant and non-resistant pathogens

This review details the antimicrobial applications of inorganic nanomaterials of mostly metallic form, and the augmentation of activity by surface conjugation of peptide ligands. The review is subdivided into three main sections, of which the first describes the antimicrobial activity of inorganic nanomaterials against gram-positive, gram-negative and multidrug-resistant bacterial strains. The second section highlights the range of antimicrobial peptides and the drug resistance strategies employed by bacterial species to counter lethality. The final part discusses the role of antimicrobial peptide-decorated inorganic nanomaterials in the fight against bacterial strains that show resistance. General strategies for the preparation of antimicrobial peptides and their conjugation to nanomaterials are discussed, emphasizing the use of elemental and metallic oxide nanomaterials. Importantly, the permeation of antimicrobial peptides through the bacterial membrane is shown to aid the delivery of nanomaterials into bacterial cells. By judicious use of targeting ligands, the nanomaterial becomes able to differentiate between bacterial and mammalian cells and, thus, reduce side effects. Moreover, peptide conjugation to the surface of a nanomaterial will alter surface chemistry in ways that lead to reduction in toxicity and improvements in biocompatibility

Functional assessment of subtilosin A against <em>Aeromonas</em> spp. causing gastroenteritis and hemorrhagic septicaemia

27-32Anti-Aeromonas and cell membrane lytic bacteriocin substance, subtilosin A producing Bacillus subtilis VT03 was explored. Strain VT03 was isolated from freshwater fish (Tilapia) intestine and screened for its antimicrobial activity against four pathogenic strains of Aeromonas spp. causing gastroenteritis and hemorrhagic septicaemia. Isolate (VT03) was identified showing inhibition in agar spot assay. The strain VT03 was the one exhibiting strong inhibition and identified as Bacillus subtilis using 16S rRNA sequencing. Cell free supernatant (CFS) of the strain VT03 was active against pathogenic strains of Aeromonas spp, subsequently CFS was partially purified and designated as PPB-VT03 showing inhibition against A. hydrophila ATCC 49140. PPB-VT03 completely lost its activity upon treating with proteinase K revealing that the defense molecule could be proteinaceous in nature. Based on polymerase chain reaction (PCR), functional gene coding for subtilosin A (sboA) was found to be present whereas subtilin (spaS) was absent. The role of partially purified bacteriocin of isolate VT03 (PPB-VT03) through FTIR and SEM analysis revealed the activity of cell lysis. The study demonstrated the potential use of subtilosin A producing Bacillus subtilis as a potent source for antibacterial peptide

Use of dry hydrolysate from squid and scallop product supplement in plant based practical diets for Pacific white shrimp Litopenaeus vannamei

A series of trials were designed to evaluate hydrolysates from waste streams of squid and scallop processing centers for the use in practical shrimp feeds. Towards this goal, three growth trials and a consumption trial were conducted to evaluate the use of dry hydrolysate from squid and scallop waste as specialty ingredients in commercial type feed formulations for Pacific white shrimp Litopenaeus vannamei. In the three six-week growth trials, the basal diet (35% crude protein, 8% lipid) consisted primarily of soybean meal (SBM), corn protein concentrate, corn starch, and whole wheat. In Trial 1, the basal diet was supplemented with 3%, 6%, and 9% from squid hydrolysate (Squ) or scallop hydrolysate (Sca) as well as two treatments using SBM which was impregnated with the hydrolysate prior to use. In Trial 2, the basal diet was supplemented with 3% Squ or Sca, shrimp but the shrimp were offered diets in slight excess to allow for possible increases in consumption of feeds. In Trial 3, Squ and Squid meal were compared at 6%. At the end of the three growth trials, no significant differences were found in final biomass, final mean weight, percent weight gain, feed conversion ratio, and survival. Additionally, a group of shrimp (3 g initial mean weight) were used to estimate consumption of the feeds over three 1-hour feedings over three days. Interestingly, the estimated feed intake of the basal diet was significantly higher than that of diets supplemented with 3% Squ or Sca. Results of the present study indicate that Squ and Sca as well as the SBM impregnated with Squ or Sca are good marine ingredients and can be used as feed ingredients. However, no evidence of improved feed intake or enhancement of growth were observed even though the diets were plant based. Statement of relevance In this study, a series of trials were used to assess the efficacy of dry hydrolysate from squid and scallop as well as traditional squid meal use in plant based practical diets designed for the Pacific white shrimp. These findings will be useful because the feed producers are interested in how specific produce may improve performance either as a nutrient source or attractant, particularly in diets that do not contain fishmeal. The conclusion provide valuable information that indicates feed manufacturer and researchers can use these hydrolysate products as feed ingredients in diets of shrimp, but no evidence for use of these products to improve the shrimp growth performance was observed

GST M1-T1 null allele frequency patterns in geographically assorted human populations: a phylogenetic approach.

Genetic diversity in drug metabolism and disposition is mainly considered as the outcome of the inter-individual genetic variation in polymorphism of drug-xenobiotic metabolizing enzyme (XME). Among the XMEs, glutathione-S-transferases (GST) gene loci are an important candidate for the investigation of diversity in allele frequency, as the deletion mutations in GST M1 and T1 genotypes are associated with various cancers and genetic disorders of all major Population Affiliations (PAs). Therefore, the present population based phylogenetic study was focused to uncover the frequency distribution pattern in GST M1 and T1 null genotypes among 45 Geographically Assorted Human Populations (GAHPs). The frequency distribution pattern for GST M1 and T1 null alleles have been detected in this study using the data derived from literatures representing 44 populations affiliated to Africa, Asia, Europe, South America and the genome of PA from Gujarat, a region in western India. Allele frequency counting for Gujarat PA and scattered plot analysis for geographical distribution among the PAs were performed in SPSS-21. The GST M1 and GST T1 null allele frequencies patterns of the PAs were computed in Seqboot, Gendist program of Phylip software package (3.69 versions) and Unweighted Pair Group method with Arithmetic Mean in Mega-6 software. Allele frequencies from South African Xhosa tribe, East African Zimbabwe, East African Ethiopia, North African Egypt, Caucasian, South Asian Afghanistan and South Indian Andhra Pradesh have been identified as the probable seven patterns among the 45 GAHPs investigated in this study for GST M1-T1 null genotypes. The patternized null allele frequencies demonstrated in this study for the first time addresses the missing link in GST M1-T1 null allele frequencies among GAHPs

Structural characterization, functional and biological activities of an exopolysaccharide produced by probiotic Bacillus licheniformis AG-06 from Indian polyherbal fermented traditional medicine

International audienceAn exopolysaccharide (EPS) was purified from the probiotic bacterium Bacillus licheniformis AG-06 isolated from the polyherbal fermented traditional medicine (Ashwagandharishta) of Indian Ayurveda. High-performance liquid chromatography (HPLC) based compositional analysis exhibits the heteropolymeric nature of the EPS consisting of galactose, rhamnose, xylose, mannose, and glucose, as the monomeric units. Fourier-transform infrared (FT-IR) and nuclear magnetic resonance (NMR) spectroscopic analyses confirm the presence of typical carbohydrate polymer functional groups and structural units, respectively. The purified EPS demonstrates the web-like fibrous and porous nature in scanning electron microscopic and atomic force microscopic studies. The purified EPS had shown 71.83% and 67.79% of flocculation and emulsification activities, respectively. Antioxidant activity was evaluated against 2,2-diphenyl-1-picrylhydrazyl (DPPH), 2,2′-azino-bis(3-ethylbenzothiazoline-6-sulfonic acid) (ABTS), nitric oxide, and superoxide free radicals and the scavenging actions were increased in a dose-dependent manner. Moreover, the purified EPS exhibits a significant cytotoxic activity against the human lung carcinoma cells (A549), which strongly suggests the anticancer potential of the EPS derived from B. licheniformis AG-06

<i>GST M1</i>-<i>T1 null</i> allele frequency of geographically assorted human populations.

<p><i>GST M1</i>-<i>T1 null</i> allele frequency of geographically assorted human populations.</p

Phylogenetic tree of 20 different continental regions population affiliations for <i>GST M1-T1 null</i> allele frequency.

<p>The tree was produced by the UPGMA method from D_ST values in <a href="http://www.plosone.org/article/info:doi/10.1371/journal.pone.0118660#pone.0118660.t002" target="_blank">Table 2</a> and cluster with more than 50% of 1000 bootstrap replicates were included in the consensus tree obtained by Felsenstein (1989) phylogeny interference package. Major group of <i>GST M1-T1 null</i> allele frequencies were from population of Xhosa tribe, Zimbabwe, Ethiopia, Egypt, Afghanistan and Caucasian. Abbreviations used were same as those in <a href="http://www.plosone.org/article/info:doi/10.1371/journal.pone.0118660#pone.0118660.t001" target="_blank">Table 1</a>.</p