Animal & Avian Sciences

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Author: search.filters.author.Biswas, Debabrata

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    Antimicrobial Effect and Probiotic Potential of Phage Resistant Lactobacillus plantarum and its Interactions with Zoonotic Bacterial Pathogens
    (MDPI, 2019-06-05) Nagarajan, Vinod; Peng, Mengfei; Tabashsum, Zajeba; Salaheen, Serajus; Padilla, Joselyn; Biswas, Debabrata
    Development of phage-resistant probiotic particularly Lactobacillus is an alternative approach to enhance their beneficial effects as in animal feed supplements. In this study, we developed phage-resistant Lactobacillus plantarum (LP+PR) mutant and compared their antimicrobial effects and probiotic potential against zoonotic bacterial pathogens including Salmonella enterica serovar Typhimurium, enterohemorrhagic Escherichia coli (EHEC), Staphylococcus aureus, and Listeria monocytogenes with phage-sensitive L. plantarum (LP) strain. LP+PR strain showed markedly higher growth rate than wild-type LP strain. In co-culture with LP+PR and in the presence of cell-free cultural supernatants (CFCSs) of LP+PR, the growth of S. Typhimurium, EHEC, S. aureus, and L. monocytogenes were reduced significantly (P < 0.05). The adhesion ability of LP+PR was slightly higher than the LP on human epithelial INT-407 cells. Most importantly, LP+PR strain significantly inhibited the adhesive and invasive abilities of all four zoonotic pathogens to INT-407 cells (P < 0.05). Moreover, real-time qPCR revealed that in the presence of LP+PR strain or its CFCSs, expression of virulence genes of these zoonotic bacterial pathogens were suppressed significantly (P < 0.05). These findings suggest that the LP+PR strain is capable of inhibiting major zoonotic bacterial pathogens efficiently and would be a potential candidate for industrial usage in animal production or fermentation.
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    Environmental Influences of High-Density Agricultural Animal Operation on Human Forearm Skin Microflora
    (MDPI, 2020-09-26) Peng, Mengfei; Biswas, Debabrata
    The human forearm skin microbiome ecosystem contains rich and diverse microbes, which are influenced by environmental exposures. The microbial representatives can be exchanged between human and environment, specifically animals, by which they share certain or similar epidermal microbes. Livestock and poultry are the microbial sources that are associated with the transmission of community-based pathogenic infections. Here, in this study, we proposed investigating the environmental influences introduced by livestock/poultry operations on forearm skin microflora of on-site farm workers. A total of 30 human skin swab samples were collected from 20 animal workers in dairy or integrated farms and 10 healthy volunteer controls. The skin microbiome was 16S metagenomics that were sequenced with Illumina MiSeq system. For skin microbial community analysis, the abundance of major phyla and genera as well as alpha and beta diversities were compared across groups. We identified distinctive microbial compositional patterns on skin of workers in farm with different animal commodities. Workers in integrated farms containing various animals were associated with higher abundances of epidermal Proteobacteria, especially Pseudomonas and Acinetobacter, but lower Actinobacteria, especially Corynebacterium and Propionibacterium. For those workers with frequent dairy cattle operations, their Firmicutes in the forearm skin microbiota were enriched. Furthermore, farm animal operations also reduced Staphylococcus and Streptococcus, as well as modulated the microbial biodiversity in farm workers’ skin microbiome. The alterations of forearm skin microflora in farm workers, influenced by their frequent farm animal operations, may increase their risk in skin infections with unusual pathogens and epidermal diseases.
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    Influence of Manure Application on the Soil Bacterial Microbiome in Integrated Crop-Livestock Farms in Maryland
    (MDPI, 2021-12-15) Peng, Mengfei; Tabashsum, Zajeba; Millner, Patricia; Parveen, Salina; Biswas, Debabrata
    As a traditional agricultural system, integrated crop-livestock farms (ICLFs) involve the production of animals and crops in a shared environment. The ICLFs in the mid-Atlantic region of the United States practice sustainable manure aging or composting processes to provide an on-farm source of soil amendment for use as natural fertilizer and soil conditioner for crop production. However, crop fertilization by soil incorporation of aged manure or compost may introduce different microbes and alter the soil microbial community. The aim of this study was to characterize the influence of aged or composted manure application on the diversity of soil bacterial community in ICLFs. Soil samples from six ICLFs in Maryland were collected before (pre-crop) and during the season (2020–2021) and used to analyze soil bacterial microbiome by 16S rDNA sequencing. Results showed that both phylum- and genus-level alterations of soil bacterial communities were associated with amendment of aged or composted manure. Particularly, Proteobacteria and Actinobacteria were enriched, while Acidobacteria, Bacteroidetes, Planctomycetes, Firmicutes, and Chloroflexi were reduced after manure product application. Meanwhile, the relative abundance of Bacillus was decreased, while two zoonotic pathogens, Salmonella and Listeria, were enriched by manure amendments. Overall, animal manure amendment of soil increased the phylogenetic diversity, but reduced the richness and evenness of the soil bacterial communities. Although manure composting management in ICLFs benefits agricultural sustainable production, the amendments altered the soil bacterial communities and were associated with the finding of two major zoonotic bacterial pathogens, which raises the possibility of their potential transfer to fresh horticultural produce crops that may be produced on the manured soils and then subsequently consumed without cooking.
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    Application of orange essential oil as an antistaphylococcal agent in a dressing model
    (Springer Nature, 2012-08-16) Muthaiyan, Arunachalam; Biswas, Debabrata; Crandall, Philip G; Wilkinson, Brian J; Ricke, Steven C
    Staphylococcus aureus is the pathogen most often and prevalently involved in skin and soft tissue infections. In recent decades outbreaks of methicillin-resistant S. aureus (MRSA) have created major problems for skin therapy, and burn and wound care units. Topical antimicrobials are most important component of wound infection therapy. Alternative therapies are being sought for treatment of MRSA and one area of interest is the use of essential oils. With the increasing interest in the use and application of natural products, we screened the potential application of terpeneless cold pressed Valencia orange oil (CPV) for topical therapy against MRSA using an in vitro dressing model and skin keratinocyte cell culture model. The inhibitory effect of CPV was determined by disc diffusion vapor assay for MRSA and vancomycin intermediate-resistant S. aureus (VISA) strains. Antistaphylococcal effect of CPV in an in vitro dressing model was tested on S. aureus inoculated tryptic soya agar plate. Bactericidal effect of CPV on MRSA and VISA infected keratinocyte cells was examined by enumeration of extra- and intra-cellular bacterial cells at different treatment time points. Cytotoxic effects on human skin cells was tested by adding CPV to the keratinocyte (HEK001) cells grown in serum free KSFM media, and observed by phase-contrast microscope. CPV vapour effectively inhibited the MRSA and VISA strains in both disc diffusion vapour assay and in vitro dressing model. Compared to untreated control addition of 0.1% CPV to MRSA infected keratinocyte decreased the viable MRSA cells by 2 log CFU/mL in 1 h and in VISA strain 3 log CFU/mL reduction was observed in 1 h. After 3 h viable S. aureus cells were not detected in the 0.2% CPV treatment. Bactericidal concentration of CPV did not show any cytotoxic effect on the human skin keratinocyte cells in vitro. At lower concentration addition of CPV to keratinocytes infected with MRSA and VISA rapidly killed the bacterial cells without causing any toxic effect to the keratinocytes. Therefore, the results of this study warrant further in vivo study to evaluate the potential of CPV as a topical antistaphylococcal agent.
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    Synbiotic-like effect of linoleic acid overproducing Lactobacillus casei with berry phenolic extracts against pathogenesis of enterohemorrhagic Escherichia coli
    (Springer Nature, 2019-07-27) Tabashsum, Zajeba; Peng, Mengfei; Bernhardt, Cassendra; Patel, Puja; Carrion, Michael; Biswas, Debabrata
    Majority of enteric infections are foodborne and antimicrobials including antibiotics have been used for their control and treatment. However, probiotics or prebiotics or their combination offer a potential alternative intervention strategy for improving the host health and preventing foodborne pathogen colonization/infections in reservoir. Further, bioengineered probiotics expressing bioactive products to achieve specific function is highly desirable. Recently, we over-expressed mcra (myosin cross-reactive antigen) gene in Lactobacillus casei (Lc) and developed a bioengineered probiotics Lc + CLA which produce higher amounts of metabolites including conjugated linoleic acid (CLA). Furthermore, we also reported that prebiotic like components such as berry pomace (byproduct) phenolic extracts (BPEs) can enhance the growth of probiotics and improved the beneficial effects of probiotics. In this study, we evaluated the antimicrobial effect of modified Lc + CLA in combination of BPEs on growth, survival and pathogenesis of enterohemorrhagic Escherichia coli (EHEC).