Animal & Avian Sciences
Permanent URI for this communityhttp://hdl.handle.net/1903/2210
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Item BIOACTIVE LACTOBACILLUS CASEI IN REDUCING GROWTH AND COLONIZATION OF CAMPYLOBACTER JEJUNI(2018) Tabashsum, Zajeba; Biswas, Debabrata; Animal Sciences; Digital Repository at the University of Maryland; University of Maryland (College Park, Md.)Campylobacter jejuni (CJ) is one of the pre-dominant causative agents of acute gastroenteritis in the US and occurs commonly through handling/consumption of contaminated poultry products. Probiotics with enhanced bioactive metabolites such as conjugated linoleic acids (CLAs) play crucial role in improving host health and act as antimicrobials. Further, prebiotic like components such as bioactive phenolics from berry pomace extract (BPE) can stimulate growth of beneficial microbes including Lactobacillus casei (LC) and inhibit bacterial pathogens in vitro. In this study, we aimed to assess efficiency of CLA overproducing LC (LC+mcra) alone or in presence of BPE against CJ. LC+mcra alone or LC+mcra with BPE reduced CJ growth, adhesion and invasion efficiency to cultured cells and also altered physicochemical properties, gene expressions related to virulence. These findings suggest, BPE and LC+mcra in combination may able to prevent CJ colonization in poultry and reduce cross-contamination, hence control foodborne infections with CJ in human.Item REDUCED CAMPYLOBACTER INFECTION AND ENHANCED PERFORMANCE IN POULTRY WITH BIOACTIVE PHENOLICS THROUGH EPIGENETIC MODULATION OF THE GUT MICROBIOME(2017) Salaheen, Serajus; Biswas, Debabrata; Animal Sciences; Digital Repository at the University of Maryland; University of Maryland (College Park, Md.)Campylobacter jejuni, a major enteric pathogen and a natural resident in the poultry gut, causes gastrointestinal illness followed by severe post-infection complications, including Guillain-Barré syndrome, reactive arthritis, myocarditis, and ulcerative colitis in humans. Risk assessment studies have projected a 30-fold reduction in human campylobacteriosis cases with only a 100-fold reduction in the number of C. jejuni colonizing the poultry gut. Current commercial poultry production practices involve use of antibiotic growth promoters (AGP); modulation of gut microbiota with AGPs for food safety and enhanced performance in poultry can be justified until acquisition of antibiotic resistance in zoonoses through inter-bacterial transfer of antibiotic resistance genes (ARGs) in a complex microbial community is considered. As an alternative, natural phenolics extracted from by-products of berry juice industry, with antimicrobial, anti-inflammatory, anticarcinogenic, antioxidant and vasodilatory activities, demonstrate promising prospects. In this study, we adopted mass-spectrometry, microbiological, phylogenetic, and metagenomic approaches to evaluate bioactive phenolic extracts (BPE) from blueberry (Vaccinium corymbosum) and blackberry (Rubus fruticosus) pomaces as AGP alternative. We detected that major phenolics in BPE included, but were not limited to, apigenin, catechol, chlorogenic acid, cinnamic acid, coumarin, ellagic acid, eugenols, flavan, gallic acid, gingerol, glucosides, glucuronides, myricetin, phenols, quercetin, quinones, rhamnosides, stilbenol, tannins, triamcinolone, and xanthine. BPE reduced C. jejuni growth and motility in vitro, resulting in lower adherence and invasiveness to chicken fibroblast cells. Anti-inflammatory effects of BPE significantly reduced the expression of pro-inflammatory cytokine genes in chick macrophage cell line ex vivo. Furthermore, BPE reduced the colonization of C. jejuni in broiler cecum by 1 to 5 logs while increasing broiler weight by 6% compared to 9.5% with commercial AGPs. Metagenomic analysis of broiler gut indicated that BPE caused an AGP-like pattern in bacterial communities with a comparative increase of Firmicutes and a concomitant reduction of Bacteroidetes in broiler ceca. AGP supplementation clearly caused phage induction and a richer resistome profile in the cecal microbiome compared to BPE. Functional characterization of cecal microbiomes revealed a significant variation in the abundance of genes involved in energy and carbohydrate metabolism. Our findings established a baseline upon which mechanisms of plant based antimicrobial performance-enhancers in regulation of animal growth can be investigated.Item Campylobacter spp. in bulk tank milk and milk filters from US dairy farms(2015) Del Collo, Laura P; Biswas, Debabrata; Animal Sciences; Digital Repository at the University of Maryland; University of Maryland (College Park, Md.)Campylobacter spp. are a common cause of foodborne outbreaks associated with raw or unpasteurized milk, and Campylobacter spp. have also been detected on most dairies in the US. An estimate of the prevalence of thermophilic Campylobacter spp. in bulk tank milk (BTM) on US dairy operations was determined as part of the National Animal Health Monitoring System’s Dairy 2014 study. Campylobacter spp. were detected in the BTM and milk filters from 34.2% of the 234 dairies. Isolates were obtained from 18.4% of the dairies. C. jejuni was the most frequently isolated species, and this species is also the most common cause of human infection. When resistance to a panel of nine antimicrobials was tested, 68.4% of C. jejuni isolates were resistant to tetracycline. This survey suggests that BTM from US dairies can be contaminated with pathogenic Campylobacter spp., and the consumption of unpasteurized, raw milk represents a human health risk.