Impacts of Poultry House Environment on Poultry Litter Bacterial Community Composition

Viral and bacterial pathogens are a significant economic concern to the US broiler industry and the ecological epicenter for poultry pathogens is the mixture of bedding material, chicken excrement and feathers that comprises the litter of a poultry house. This study used high-throughput sequencing to assess the richness and diversity of poultry litter bacterial communities, and to look for connections between these communities and the environmental characteristics of a poultry house including its history of gangrenous dermatitis (GD). Cluster analysis of 16S rRNA gene sequences revealed differences in the distribution of bacterial phylotypes between Wet and Dry litter samples and between houses. Wet litter contained greater diversity with 90% of total bacterial abundance occurring within the top 214 OTU clusters. In contrast, only 50 clusters accounted for 90% of Dry litter bacterial abundance. The sixth largest OTU cluster across all samples classified as an Arcobacter sp., an emerging human pathogen, occurring in only the Wet litter samples of a house with a modern evaporative cooling system. Ironically, the primary pathogenic clostridial and staphylococcal species associated with GD were not found in any house; however, there were thirteen 16S rRNA gene phylotypes of mostly Gram-positive phyla that were unique to GD-affected houses and primarily occurred in Wet litter samples. Overall, the poultry house environment appeared to substantially impact the composition of litter bacterial communities and may play a key role in the emergence of food-borne pathogens

A novel photo-biological engineering method for Salvia miltiorrhiza-mediated fabrication of silver nanoparticles using LED lights sources and its effectiveness against Aedes aegypti mosquito larvae and microbial pathogens

In this study, Salvia miltiorrhiza-synthesized Ag nanoparticles (AgNPs) fabricated using sunlight or various LED lights were studied for their biophysical features and evaluated as larvicides against Aedes aegypti mosquitoes and growth inhibitors on different species of microbial pathogens. AgNPs production post-exposure to sunlight or different LED light conditions (i.e. blue, red, green, and white) was confirmed by characteristic surface Plasmon resonance (SPR) at maximum λ of 430, 420, 460, 450, and 460 nm, respectively. Optimization of pH, reducing extract concentration, metal ion concentration and time elapsed from the nano-biosynthesis was achieved. High-resolution transmission electron microscopy (HR-TEM) showed that most AgNPs was spherical, triangular and oval, with average size of 18.5, 28.02, 50.22, 16.26 and 10.12 nm for white, green, red, blue and sunlight, respectively. XRD confirmed the all the obtained AgNPs showed face centered cubic (fcc) crystal lattice. FT-IR analysis of all synthesized AgNPs indicated the involvement of phenol, amine, hydroxyl and amino groups in the reduction of nano-Ag. All tested AgNPs inhibited the growth of Brevibacterium linens (KACC-14346), Propionibacterium acnes (KACC 11946), Staphylococcus aureus (KACC-10768) and Staphylococcus epidermidis. As a general trend, larvicidal assays conducted on dengue and Zika virus vector Aedes aegypti showed that, after 48 h of exposure, the toxicity achieved by sunlight-fabricated AgNPs was slightly higher if compared to AgNPs fabricated using various LED lights. Overall, our research highlighted the importance of abiotic parameters, with special reference to light condition, during green nanosynthesis of antimicrobials and larvicides