Validating the use of a newly developed cinnamaldehyde product in commercial broiler production.

Essential oils (EOs) have been considered as an alternative to antibiotics for animal production. In the current study, 4 trials were conducted on a commercial broiler farm to investigate the effects of dietary supplementation of an encapsulated cinnamon EO product (NE-OFF) on the bird growth performance, gut health, and gene expression in the ileum, spleen, and liver relating to the host response to heat and other stresses, including potential NE challenge. In each trial, approximately 30,000 Cobb or Ross broilers were randomly allocated to 4 treatments: a raised without antibiotics (RWA) commercial diet as positive control, an adjusted RWA commercial diet as negative control, and the negative control diet supplemented with 2 different dosages of NE-OFF, which was added during feed pelleting. Although the final average body weight did not differ significantly among treatment groups, birds fed NE-OFF had an increased ratio of villus height and crypt depth in the jejunum, and reduced fecal oocyst counts. Trial 2 was conducted in the summer and had a necrotic enteritis (NE) outbreak. The supplementation of NE-OFF reduced the NE incidence and bird mortality. The samples from Trial 2 were hence selected for the analyses of Clostridium perfringens and NetB toxin gene abundance in the ileum, and host responses. The C. perfringens population appeared to be positively correlated with the NetB gene abundance. The gene expression analysis suggested that NE-OFF supplementation improved nutrient absorption and transportation as well as antioxidant activities to help the birds against stress. These on-farm trial results support the hypothesis that the use of NE-OFF as a feed additive can improve bird gut health and performance in commercial broiler production, especially for preventing NE outbreaks when birds are under stress.

Dynamic effects of black soldier fly larvae meal on the cecal bacterial microbiota and prevalence of selected antimicrobial resistant determinants in broiler chickens.

BACKGROUND: We had earlier described the growth-promoting and -depressive effects of replacing soybean meal (SBM) with low (12.5% and 25%) and high (50% and 100%) inclusion levels of black soldier fly larvae meal (BSFLM), respectively, in Ross x Ross 708 broiler chicken diets. Herein, using 16S rRNA gene amplicon sequencing, we investigated the effects of replacing SBM with increasing inclusion levels (0-100%) of BSFLM in broiler diets on the cecal bacterial community composition at each growth phase compared to broilers fed a basal corn-SBM diet with or without the in-feed antibiotic, bacitracin methylene disalicylate (BMD). We also evaluated the impact of low (12.5% and 25%) inclusion levels of BSFLM (LIL-BSFLM) on the prevalence of selected antimicrobial resistance genes (ARGs) in litter and cecal samples from 35-day-old birds. RESULTS: Compared to a conventional SBM-based broiler chicken diet, high (50 to100%) inclusion levels of BSFLM (HIL-BSFLM) significantly altered the cecal bacterial composition and structure, whereas LIL-BSFLM had a minimal effect. Differential abundance analysis further revealed that the ceca of birds fed 100% BSFLM consistently harbored a ~ 3 log-fold higher abundance of Romboutsia and a ~ 2 log-fold lower abundance of Shuttleworthia relative to those fed a BMD-supplemented control diet at all growth phases. Transient changes in the abundance of several potentially significant bacterial genera, primarily belonging to the class Clostridia, were also observed for birds fed HIL-BSFLM. At the finisher phase, Enterococci bacteria were enriched in the ceca of chickens raised without antibiotic, regardless of the level of dietary BSFLM. Additionally, bacitracin (bcrR) and macrolide (ermB) resistance genes were found to be less abundant in the ceca of chickens fed antibiotic-free diets, including either a corn-SBM or LIL-BSFLM diet. CONCLUSIONS: Chickens fed a HIL-BSFLM presented with an imbalanced gut bacterial microbiota profile, which may be linked to the previously reported growth-depressing effects of a BSFLM diet. In contrast, LIL-BSFLM had a minimal effect on the composition of the cecal bacterial microbiota and did not enrich for selected ARGs. Thus, substitution of SBM with low levels of BSFLM in broiler diets could be a promising alternative to the antibiotic growth promoter, BMD, with the added-value of not enriching for bacitracin- and macrolide-associated ARGs.

Microbiome of Ceca from Broiler Chicken Vaccinated or Not against Coccidiosis and Fed Berry Pomaces.

American cranberry (Vaccinium macrocarpon) and lowbush/wild blueberry (V. angustifolium) pomace are polyphenol-rich products having potentially beneficial effects in broiler chickens. This study investigated the cecal microbiome of broiler-vaccinated or non-vaccinated birds against coccidiosis. Birds in each of the two groups (vaccinated or non-vaccinated) were fed a basal non-supplemented diet (NC), a basal diet supplemented with bacitracin (BAC), American cranberry (CP), and lowbush blueberry (BP) pomace alone or in combination (CP + BP). At 21 days of age, cecal DNA samples were extracted and analyzed using both whole-metagenome shotgun sequencing and targeted-resistome sequencing approaches. Ceca from vaccinated birds showed a lower abundance of Lactobacillus and a higher abundance of Escherichia coli than non-vaccinated birds (p < 0.05). The highest and lowest abundance of L. crispatus and E. coli, respectively, were observed in birds fed CP, BP, and CP + BP compared to those from NC or BAC treatments (p < 0.05). Coccidiosis vaccination affected the abundance of virulence genes (VGs) related to adherence, flagella, iron utilization, and secretion system. Toxin-related genes were observed in vaccinated birds (p < 0.05) in general, with less prevalence in birds fed CP, BP, and CP + BP than NC and BAC (p < 0.05). More than 75 antimicrobial resistance genes (ARGs) detected by the shotgun metagenomics sequencing were impacted by vaccination. Ceca from birds fed CP, BP, and CP + BP showed the lowest (p < 0.05) abundances of ARGs related to multi-drug efflux pumps, modifying/hydrolyzing enzyme and target-mediated mutation, when compared to ceca from birds fed BAC. Targeted metagenomics showed that resistome from BP treatment was distant to other groups for antimicrobials, such as aminoglycosides (p < 0.05). Significant differences in the richness were observed between the vaccinated and non-vaccinated groups for aminoglycosides, ß-lactams, lincosamides, and trimethoprim resistance genes (p < 0.05). Overall, this study demonstrated that dietary berry pomaces and coccidiosis vaccination significantly impacted cecal microbiota, virulome, resistome, and metabolic pathways in broiler chickens.

Growth performance, organ weight, and plasma metabolites in broiler chickens fed corn-soybean meal diet containing berry pomaces and fed without or with multienzymes supplement.

This study evaluated effects of feeding low-bush wild blueberry (LBP) and organic American cranberry (CRP) pomaces without or with multienzyme supplement (ENZ) on growth performance, organ weight and plasma metabolites in broiler chickens. Nonenzyme-fed (no-ENZ: n = 1,575) and enzyme-fed (ENZ: n = 1,575) day-old male Cobb500 broilers were placed in floor pens (45 chicks/pen) and allocated to five corn-soybean meal-based diets: a basal diet supplemented with either bacitracin methylene disalicylate (BMD, 55 mg/kg), 0.5 or 1% of CRP or LBP in a 2 × 5 factorial design for 35-day experiment. Body weight (BW), feed intake (FI) and mortality were recorded whereas BW gain (BWG) and feed conversion ratio (FCR) were calculated. Birds were sampled at days 21 and 35 for organ weights and plasma metabolites. There were no interactions between diet and ENZ on any parameter (P > 0.05) and no effect of ENZ on overall (d 0-35) growth performance and organ weights (P > 0.05). Birds fed BMD were heavier (P < 0.05) at d 35 and had better overall FCR than berry-supplemented birds. Birds fed 1% LBP had poor FCR than birds fed 0.5% CRP. Birds fed LBP exhibited heavier liver (P < 0.05) than birds fed BMD or 1% CRP. The highest plasma concentrations of aspartate transaminase (AST), creatine kinase (CK) at d 28 and gamma-glutamyl transferase (GGT) at d 35 were found in ENZ-fed birds (P < 0.05). At d 28, birds fed 0.5% LBP showed higher plasma AST and CK concentrations (P < 0.05). However, CRP feeding resulted in a lower plasma CK level compared with BMD feeding (P < 0.05). The lowest cholesterol level was detected in 1% CRP-fed birds. In conclusion, this study showed no ENZ effects to potentiate berry pomaces on the overall growth performance of broilers (P < 0.05. However, plasma profiles revealed the potential of ENZ to modulate the metabolism of pomace-fed broilers. LBP increased BW during the starter phase, while CRP increased BW during the grower phase.

Comparative Genomic Analysis of Enterococci across Sectors of the One Health Continuum.

Enterococci are Gram-positive bacteria that can be isolated from a variety of environments including soil, water, plants, and the intestinal tract of humans and animals. Although they are considered commensals in humans, Enterococcus spp. are important opportunistic pathogens. Due to their presence and persistence in diverse environments, Enterococcus spp. are ideal for studying antimicrobial resistance (AMR) from the One Health perspective. We undertook a comparative genomic analysis of the virulome, resistome, mobilome, and the association between the resistome and mobilome of 246 E. faecium and 376 E. faecalis recovered from livestock (swine, beef cattle, poultry, dairy cattle), human clinical samples, municipal wastewater, and environmental sources. Comparative genomics of E. faecium and E. faecalis identified 31 and 34 different antimicrobial resistance genes (ARGs), with 62% and 68% of the isolates having plasmid-associated ARGs, respectively. Across the One Health continuum, tetracycline (tetL and tetM) and macrolide resistance (ermB) were commonly identified in E. faecium and E. faecalis. These ARGs were frequently associated with mobile genetic elements along with other ARGs conferring resistance against aminoglycosides [ant(6)-la, aph(3')-IIIa], lincosamides [lnuG, lsaE], and streptogramins (sat4). Study of the core E. faecium genome identified two main clades, clade 'A' and 'B', with clade A isolates primarily originating from humans and municipal wastewater and carrying more virulence genes and ARGs related to category I antimicrobials. Overall, despite differences in antimicrobial usage across the continuum, tetracycline and macrolide resistance genes persisted in all sectors.

Virulence potential of antimicrobial-resistant extraintestinal pathogenic Escherichia coli from retail poultry meat in a Caenorhabditis elegans model.

Healthy poultry can be a reservoir for extraintestinal pathogenic Escherichia coli (ExPEC), some of which could be multidrug resistant to antimicrobials. These ExPEC strains could contaminate the environment and/or food chain representing thus, food safety and human health risk. However, few studies have shown the virulence of poultry-source antimicrobial-resistant (AMR) ExPEC in humans. This study characterized AMR ExPEC and investigated the virulence potential of some of their isolates in a Caenorhabditis elegans infection model. A total of 46 E. coli isolates from poultry (chicken, n = 29; turkey, n = 12) retail meats and chicken feces (n = 4), or humans (n = 1) were sequenced and identified as ExPEC. Except eight, all remaining 38 ExPEC isolates were resistant to at least one antibiotic and carried corresponding antimicrobial resistance genes (ARGs). About 27 of the 46 ExPEC isolates were multidrug-resistant (≥3 antibiotic classes). Seven ExPEC isolates from chicken or turkey meats were of serotype O25:H4 and sequence type (ST) 131 which clustered with an isolate from a human urinary tract infection (UTI) case having the same serotype and ST. The C. elegans challenge model using eight of studied ExPEC isolates harboring various ARGs and virulence genes (VGs) showed that regardless of their ARG or VG numbers in tested poultry meat and feces, ExPEC significantly reduced the life span of the nematode (P < 0.05) similarly to a human UTI isolate. This study indicated the pathogenic potential of AMR ExPEC from retail poultry meat or feces, but more studies are warranted to establish their virulence in poultry and human. Furthermore, relationships between specific resistance profiles and/or VGs in these E. coli isolates for their pathogenicity deserve investigations.

Antioxidative and Cytoprotective Efficacy of Ethanolic Extracted Cranberry Pomace against Salmonella Enteritidis Infection in Chicken Liver Cells.

Salmonella enterica serovar Enteritidis is a globally significant zoonotic foodborne pathogen. Chicken liver is a vital organ that has been recently implicated in several reported human salmonellosis outbreaks in the U.S. One promising strategy for reducing Salmonella in chickens could be through supplementation with natural antimicrobial additives. Ethanolic extracted cranberry pomace (CPOH) is an excellent source of bioactive polyphenolic compounds with antioxidant and antimicrobial activities. However, the protective effect of CPOH against S. Enteritidis-induced chicken hepatic cell damage remains unclear. In this study, we used a chicken hepatoma cell (LMH) infection model to investigate the protective effects and potential mechanisms of CPOH. CPOH increased the viability of S. Enteritidis-infected LMH cells. Furthermore, CPOH reduced the adhesion and invasion of S. Enteritidis to LMH cells. CPOH downregulated the expression of Rho GTPase genes that are essential for Salmonella's entry into LMH cells. Additionally, the expression of antioxidant regulatory genes, such as Nrf2, HO-1, Txn, and Gclc, was increased. Our data show that CPOH effectively protected LMH cells from cell damage through the inhibition of S. Enteritidis adhesion and invasion, as well as the induction of the expression of master antioxidant genes. These findings offer opportunities to develop sustainable, safe, and economic strategies to reduce the colonization and pathogenesis of Salmonella.

Effects of partial or complete replacement of soybean meal with commercial black soldier fly larvae (Hermetia illucens) meal on growth performance, cecal short chain fatty acids, and excreta metabolome of broiler chickens.

Black soldier fly larvae meal (BSFLM) is receiving great attention as a rich source of protein and antimicrobials for poultry. Therefore, we evaluated the effects of partially or completely replacing soybean meal (SBM) with commercial BSFLM on growth performance, tibia traits, cecal short chain fatty acid (SCFA) concentrations, and excreta metabolomes in broiler chickens (Gallus gallus domesticus). A total of 480 day-old male Ross × Ross 708 chicks were assigned to 6 diets (8 replicates/diet): a basal corn-SBM diet with in-feed bacitracin methylene disalicylate (BMD), a corn-SBM diet without BMD (0% BSFLM), and four diets in which the SBM was substituted with 12.5, 25, 50, and 100% BSFLM. Body weight (BW), feed intake (FI) and cumulative feed conversion ratio (cFCR) were monitored on days 14, 28, and 35. Cecal SCFA levels were determined on days 14, 28, and 35. Tibia traits and excreta metabolomes were determined on day (d) 35. On d14, birds fed 12.5 and 25% BSFLM had a similar BW, FI, and cFCR as birds fed BMD (P > 0.05). On d 35, birds fed 12.5% BSFLM had a similar BW, FI and cFCR as birds fed BMD or 0% BSFLM (P > 0.05). For each phase, birds fed 100% BSFLM had a lower BW, FI and higher cFCR than birds fed BMD or 0% BSFLM (P < 0.05). On d 35, BW decreased linearly, quadratically, and cubically with increasing levels of BSFLM (P < 0.01). Overall (d 0-35), BSFLM linearly, quadratically, and cubically decreased FI and quadratically and cubically increased cFCR (P < 0.01). Quadratic responses were observed for tibia fresh weight (P = 0.049) and ash content (P = 0.022). BSFLM did not impact cecal SCFAs levels. The excreta metabolome of birds fed 100% BSFLM clustered independently from all other groups and exhibited greater levels of putatively identified methionine, lysine, valine, glutamine, histidine and lower levels of arginine as compared to all diets. Taken together, substitution of SBM with ≤25% of BSFLM in the starter phase may be used as an alternative to BMD.

A narrative review of the interconnection between pilot acute stress, startle, and surprise effects in the aviation context: Contribution of physiological measurements.

Aviation remains one of the safest modes of transportation. However, an inappropriate response to an unexpected event can lead to flight incidents and accidents. Among several contributory factors, startle and surprise, which can lead to or exacerbate the pilot's state of stress, are often cited. Unlike stress, which has been the subject of much study in the context of driving and piloting, studies on startle and surprise are less numerous and these concepts are sometimes used interchangeably. Thus, the definitions of stress, startle, and surprise are reviewed, and related differences are put in evidence. Furthermore, it is proposed to distinguish these notions in the evaluation and to add physiological measures to subjective measures in their study. Indeed, Landman's theoretical model makes it possible to show the links between these concepts and studies using physiological parameters show that they would make it possible to disentangle the links between stress, startle and surprise in the context of aviation. Finally, we draw some perspectives to set up further studies focusing specifically on these concepts and their measurement.

Production systems and important antimicrobial resistant-pathogenic bacteria in poultry: a review.

Economic losses and market constraints caused by bacterial diseases such as colibacillosis due to avian pathogenic Escherichia coli and necrotic enteritis due to Clostridium perfringens remain major problems for poultry producers, despite substantial efforts in prevention and control. Antibiotics have been used not only for the treatment and prevention of such diseases, but also for growth promotion. Consequently, these practices have been linked to the selection and spread of antimicrobial resistant bacteria which constitute a significant global threat to humans, animals, and the environment. To break down the antimicrobial resistance (AMR), poultry producers are restricting the antimicrobial use (AMU) while adopting the antibiotic-free (ABF) and organic production practices to satisfy consumers' demands. However, it is not well understood how ABF and organic poultry production practices influence AMR profiles in the poultry gut microbiome. Various Gram-negative (Salmonella enterica serovars, Campylobacter jejuni/coli, E. coli) and Gram-positive (Enterococcus spp., Staphylococcus spp. and C. perfringens) bacteria harboring multiple AMR determinants have been reported in poultry including organically- and ABF-raised chickens. In this review, we discussed major poultry production systems (conventional, ABF and organic) and their impacts on AMR in some potential pathogenic Gram-negative and Gram-positive bacteria which could allow identifying issues and opportunities to develop efficient and safe production practices in controlling pathogens.

Effects of bacterial-derived antimicrobial solutions on shelf-life, microbiota and sensory attributes of raw chicken legs under refrigerated storage condition.

In the present study, bacterial-derived antimicrobial agents included 5 mM reuterin combined with either 103.91 mM lactic acid (RL) or 0.08 µM microcin J25 (RJ) were evaluated for their effects on the microbiota and sensory attributes of raw chicken legs. Peracetic acid (13.67 mM), a conventional chemical commonly used in the poultry industry, was used as a positive control to compare efficacy. The chicken legs were sprayed with antimicrobial solutions and aerobically stored at 4 °C for 10 days. The RL treatment maintained the total viable count below the limit of 7 log CFU/g until the 8th day. Therefore, compared to the nontreated group, shelf-life was extended by 3 days in the RL treated group. The RJ treatment extended the shelf-life to 7 days, which is similar to what was achieved with the use of peracetic acid. Based on culture-independent amplicon sequencing, the RL and RJ treatments affected the microbial community on the chicken legs, inducing a delay in the increase of Pseudomonas, Psychrobacter and Carnobacterium while decreasing of Shigella. Significant decreases in sensory scores occurred in the nontreated group, while slight changes occurred in the combinations treated groups over the same period. Overall, sensory property scores for chicken legs treated with RL and RJ remained higher (P < 0.05) than those treated with peracetic acid or without antimicrobial agents. The antimicrobial combinations delayed the deterioration of sensory attributes throughout the storage period. These results suggest that RL and RJ provide a promising natural-sourced antimicrobial approach to control the growth of spoilage microorganisms on chicken legs.

Effects of litter from antimicrobial-fed broiler chickens on soil bacterial community structure and diversity.

This study examined changes in soil bacterial community composition and diversity in response to fertilization with litter from chickens fed a diet without antibiotics and with bambermycin, penicillin, bacitracin, salinomycin, or mix of salinomycin and bacitracin. Litter (27.5 T/ha) was applied to 24 agricultural plots in the Fraser Valley of British Columbia. Nonfertilized plots were used as a negative control. Soil samples collected from the studied plots were used to quantify Escherichia coli by plate counts, and Clostridium perfringens by qPCR. The 16S rRNA gene sequencing was performed for microbiota analysis. Following litter application in December, the population size of E. coli was 5.4 log CFU/g; however, regardless of treatments, the results revealed 5.2 and 1.4 log CFU/g of E. coli in soil sampled in January and March, respectively. Fertilization with litter from antibiotic-treated birds increased (P < 0.05) the relative abundance of Proteobacteria, Actinobacteria, and Firmicutes in soil, but decreased Acidobacteria and Verrucomicrobia groups. The alpha diversity parameters were higher (P < 0.05) in nonfertilized soil compared to the fertilized ones, suggesting that litter application was a major factor in shaping the soil bacterial communities. These results may help develop efficient litter management strategies like composting, autoclaving, or anaerobic digestion of poultry litter before application to land for preservation of soil health and crop productivity.

Neural substrates of saccadic adaptation: Plastic changes versus error processing and forward versus backward learning.

Previous behavioral, clinical, and neuroimaging studies suggest that the neural substrates of adaptation of saccadic eye movements involve, beyond the central role of the cerebellum, several, still incompletely determined, cortical areas. Furthermore, no neuroimaging study has yet tackled the differences between saccade lengthening ("forward adaptation") and shortening ("backward adaptation") and neither between their two main components, i.e. error processing and oculomotor changes. The present fMRI study was designed to fill these gaps. Blood-oxygen-level-dependent (BOLD) signal and eye movements of 24 healthy volunteers were acquired while performing reactive saccades under 4 conditions repeated in short blocks of 16 trials: systematic target jump during the saccade and in the saccade direction (forward: FW) or in the opposite direction (backward: BW), randomly directed FW or BW target jump during the saccade (random: RND) and no intra-saccadic target jump (stationary: STA). BOLD signals were analyzed both through general linear model (GLM) approaches applied at the whole-brain level and through sensitive Multi-Variate Pattern Analyses (MVPA) applied to 34 regions of interest (ROIs) identified from independent 'Saccade Localizer' functional data. Oculomotor data were consistent with successful induction of forward and backward adaptation in FW and BW blocks, respectively. The different analyses of voxel activation patterns (MVPAs) disclosed the involvement of 1) a set of ROIs specifically related to adaptation in the right occipital cortex, right and left MT/MST, right FEF and right pallidum; 2) several ROIs specifically involved in error signal processing in the left occipital cortex, left PEF, left precuneus, Medial Cingulate cortex (MCC), left inferior and right superior cerebellum; 3) ROIs specific to the direction of adaptation in the occipital cortex and MT/MST (left and right hemispheres for FW and BW, respectively) and in the pallidum of the right hemisphere (FW). The involvement of the left PEF and of the (left and right) occipital cortex were further supported and qualified by the whole brain GLM analysis: clusters of increased activity were found in PEF for the RND versus STA contrast (related to error processing) and in the left (right) occipital cortex for the FW (BW) versus STA contrasts [related to the FW (BW) direction of error and/or adaptation]. The present study both adds complementary data to the growing literature supporting a role of the cerebral cortex in saccadic adaptation through feedback and feedforward relationships with the cerebellum and provides the basis for improving conceptual frameworks of oculomotor plasticity and of its link with spatial cognition.

Effects of drinking water supplementation with Lactobacillus reuteri, and a mixture of reuterin and microcin J25 on the growth performance, caecal microbiota and selected metabolites of broiler chickens.

BACKGROUND: Since the overuse of antibiotics in animal production has led to a selection of antibiotic-resistant pathogens that affect humans and animals as well. Scientists are therefore searching for novel natural alternatives to antibiotics. In this study Lactobacillus reuteri and a combination of reuterin and microcin J25 (RJ) were evaluated as promoters of growth and modulators of the cecal microbiota and metabolite profiles in broiler chickens. One-day-old Cobb 500 male broilers were distributed to 8 treatments: negative control (without antibiotic), positive control (bacitracin), three concentrations of RJ and three doses of L. reuteri plus glycerol. The birds (2176, 34 per pen, 8 pens per treatment) were reared for 35 d. RESULTS: The body weight of the bacitracin and 5 mmol/L reuterin combined with 0.08 µmol/L microcin J25 (10RJ) treatment group was significantly higher than that of the negative control group (P < 0.05). L. reuteri had no significant effect on broiler growth. MiSeq high-throughput sequencing of 16S rRNA showed clustering of cecal microbial operational taxonomic unit diversity according to treatment. The influence of bacitracin and 10RJ on bacterial community overall structure was similar. They promoted Ruminococcaceae, Lachnospiraceae and Lactobacillaceae, increased the relative abundance of Faecalibacterium and decreased the abundance of Bacteroides and Alistipes, while the negative control condition favored Bacteroidaceae and Rikenellaceae. Furthermore, 10RJ increased the concentration of short-chain fatty acid in the cecum and changed the metabolome overall. CONCLUSIONS: These overall suggest that 10RJ can promote a host-friendly gut environment by changing the cecal microbiome and metabolome. This combination of natural antimicrobial agents in the drinking water had a positive effect on broiler growth and may be suitable as an alternative to antibiotic growth promoters.

Virulence Genotype and Phenotype of Multiple Antimicrobial-Resistant Escherichia coli Isolates from Broilers Assessed from a "One-Health" Perspective.

ABSTRACT: Extraintestinal pathogenic Escherichia coli (ExPEC) include several serotypes that have been associated with colibacillosis in poultry and with urinary tract infections (UTIs) and newborn meningitis in humans. In this study, 57 antimicrobial-resistant E. coli from apparently healthy broiler chickens were characterized for their health and safety risks. These isolates belonged to 12 serotypes, and isolates of the same serotype were clonal based on single nucleotide variant analysis. Most of the isolates harbored plasmids; IncC and IncFIA were frequently detected. The majority of the resistant isolates harbored plasmid-mediated resistance genes, including aph(3″)-Ib, aph(6)-Id, blaCMY-2, floR, sul1, sul2, tet(A), and tet(B), in agreement with their resistant phenotypes. The class 1 integron was detected in all E. coli serotypes except O124:H25 and O7:H6. Of the 57 broiler E. coli isolates, 27 were avian pathogenic, among which 18 were also uropathogenic E. coli and the remainder were other ExPEC. The two isolates of serotype O161:H4 (ST117) were genetically related to the control avian pathogenic strains and a clinical isolate associated with UTIs. A strain of serotype O159:H45 (ST101) also was closely related to a UTI isolate. The detected virulence factors included adhesins, invasins, siderophores, type III secretion systems, and toxins in combination with other virulence determinants. A broiler isolate of serotype O7:H18 (ST38) carried the ibeA gene encoding a protein involved in invasion of brain endothelium on a 102-kbp genetic island. This isolate moderately adhered and invaded Caco-2 cells and induced mortality (42.5%) in a day-old-chick infection model. The results of this study suggest that multiple antimicrobial-resistant E. coli isolates recovered from apparent healthy broilers can be pathogenic and act as reservoirs for antimicrobial resistance genes, highlighting the necessity of their assessment in a "One-Heath" context.

Effects of encapsulated cinnamaldehyde on growth performance, intestinal digestive and absorptive functions, meat quality and gut microbiota in broiler chickens.

Essential oils are potential antimicrobial alternatives and their applications in animal feeds are limited due to their fast absorption in the upper gastrointestinal tract. This study investigated the effects of encapsulated cinnamaldehyde (CIN) at 50 mg/kg or 100 mg/kg on the growth performance, organ weights, meat quality, intestinal morphology, jejunal gene expression, nutrient digestibility, and ileal and cecal microbiota. A total of 320 male day-old broiler Cobb-500 chicks were randomly allocated to four treatments with eight pens per treatment (10 birds per pen): 1) basal diet (negative control, NC); 2) basal diet supplemented with 30 mg/kg avilamycin premix (positive control, PC); 3) basal diet with 50 mg/kg encapsulated CIN (EOL); 4) basal diet with 100 mg/kg encapsulated CIN (EOH). Despite birds fed EOH tended to increase (P = 0.05) meat pH at 24 h, all pH values were normal. Similar to PC group, meats from birds fed EOL and EOH showed a reduced (P < 0.05) Warner-Bratzler force shear (WBFS) compared to the NC group. The highest villus to crypt ratios (VH/CD; P < 0.05) were observed in broilers fed either EOL or EOH, with an average of 14.67% and 15.13% in the duodenum and 15.13% and 13.58% in the jejunum, respectively. For jejunal gene expressions, only six out of the 11 studied genes showed statistically significant differences among the dietary treatments. Gene expressions of cationic amino acid transporter 1 (CAT-1) and neutral amino acid transporter 1 (B0AT-1) were upregulated in EOH-fed birds compared to PC and NC-fed birds (P < 0.05), respectively; while the expression of proliferating cell nuclear antigen (PCNA) was downregulated in EOL-fed birds when compared to NC birds (P < 0.05). Nonetheless, the expressions of cadherin 1 (CDH-1), zonula occludens 1 (ZO-1), and maltase-glucoamylase (MG) were all upregulated (P < 0.05) in EOH-fed birds compared to PC-fed birds. The apparent ileal digestibility (AID) of dry matter, crude protein, crude fat and of all 18 tested amino acids increased in EOL-fed birds (P < 0.01). Additionally, relative abundances (%) of ileal Proteobacteria decreased, while ileal and cecal Lactobacillus increased in EOH-fed birds (P < 0.05). In conclusion, dietary encapsulated CIN improved meat quality and gut health by reducing meat WBFS, increasing VH/CD in intestines, jejunal gene expressions, AID of nutrients and beneficial ileal and cecal microbiota composition.

Effects of Vaccination Against Coccidiosis on Gut Microbiota and Immunity in Broiler Fed Bacitracin and Berry Pomace.

Feeding practices have been found to influence gut microbiota which play a major role in immunity of poultry. In the present study, changes in cecal microbiota and humoral responses resulting in the 55 ppm bacitracin (BACI), 1% each of cranberry (CP1) and wild blueberry (BP1) pomace alone or in combination (CP+BP) feeding in broiler Cobb 500 vaccinated or not against coccidiosis were investigated. In the non-vaccinated group, no significant treatment effects were observed on performance parameters. Vaccination significantly affected bird's performance parameters particularly during the growing phase from 10 to 20 days of age. In general, the prevalence of coccidiosis and necrotic enteritis (NE) was reduced by vaccination (P < 0.05). BACI-treated birds showed low intestinal lesion scores, and both CP1 and BP1 feed supplementations reduced Eimeria acervulina and Clostridium perfringens incidences similar to BACI. Vaccination induced change in serum enzymes, minerals, and lipid levels in 21-day old birds while, levels of triglyceride (TRIG) and non-esterified fatty acids (NEFA) were higher (P < 0.05) in CP1 treated non-vaccinated group than in the control. The levels of NEFA were lower in BACI- and CP1-fed birds than in the control in non-vaccinated day 28 old birds. The highest levels of all estimated three immunoglobulins (IgY, IgM, and IgA) were found in the vaccinated birds. Metagenomics analysis of the cecal bacterial community in 21-day old birds showed the presence of Firmicutes (90%), Proteobacteria (5%), Actinobacteria (2%), and Bacteroidetes (2%). In the vaccinated group, an effect of BACI was noted on Proteobacteria (P = 0.03). Vaccination and/or dietary treatments influenced the population of Lactobacillaceae, Enterobacteriaceae, Clostridiaceae, and Streptococcaceae which were among the most abundant families. Overall, this study revealed that besides their beneficial effects on performance, alike bacitracin, berry pomaces in poultry feed have profound impacts on the chicken cecal microbiota and blood metabolites that could be influenced by vaccination against coccidiosis.

Immunostimulatory Potential of Fruits and Their Extracts in Poultry.

The impact of antibiotic use for growth promotion in livestock and poultry production on the rise of antimicrobial resistance (AMR) in bacteria led to the ban of this practice in the European Union in 2006 and a restriction of antimicrobial use (AMU) in animal agriculture in Canada and the United States of America. There is a high risk of infectious diseases such as necrotic enteritis due to Clostridium perfringens, and colibacillosis due to avian pathogenic Escherichia coli in antimicrobial-free broiler chickens. Thus, efficient and cost-effective methods for reducing AMU, maintaining good poultry health and reducing public health risks (food safety) are urgently needed for poultry production. Several alternative agents, including plant-derived polyphenolic compounds, have been investigated for their potential to prevent and control diseases through increasing poultry immunity. Many studies in humans reported that plant flavonoids could modulate the immune system by decreasing production of pro-inflammatory cytokines, T-cell activation, and proliferation. Fruits, especially berries, are excellent sources of flavonoids while being rich in nutrients and other functionally important molecules (vitamins and minerals). Thus, fruit byproducts or wastes could be important resources for value-added applications in poultry production. In the context of the circular economy and waste reduction, this review summarizes observed effects of fruit wastes/extracts on the general health and the immunity of poultry.

Inhibitory Activity of Natural Synergetic Antimicrobial Consortia Against Salmonella enterica on Broiler Chicken Carcasses.

The currently most utilized antimicrobial agent in poultry processing facilities is peracetic acid, a chemical increasingly recognized as hazardous to human health. We evaluated the efficacy of mixtures of natural antimicrobial compounds, namely reuterin, microcin J25, and lactic acid, for reducing the viability of Salmonella enterica and total aerobes on broiler chicken carcasses. The compounds were compared singly and in combination with water and 0.1% peracetic acid. The minimum inhibitory concentrations of reuterin, lactic acid, and microcin J25 against S. enterica serovar Enteritidis were respectively 2 mM, 0.31%, and 0.03 µM. In vitro, the combinations of reuterin + lactic acid and reuterin + microcin J25 were synergic, making these compounds effective at four times lower concentrations than those used alone. Salmonella viable counts fell to zero within 10 min of contact with reuterin + lactic acid at 10 times the concentrations used in combination, compared to 18 h in the case of reuterin + microcin J25. Sprayed onto chilled chicken carcasses, this reuterin + lactic acid mixture reduced Salmonella spp. counts by 2.02 Log CFU/g, whereas reuterin + microcin J25 and peracetic acid reduced them by respectively 0.83 and 1.13 Log CFU/g. The synergy of reuterin with lactic acid or microcin J25 as inhibitors of bacterial growth was significant. Applied as post-chill spray, these mixtures could contribute to food safety by decreasing Salmonella counts on chicken carcasses.

Antimicrobial Resistance Phenotypes and Genotypes of Escherichia coli Isolates from Broiler Chickens Fed Encapsulated Cinnamaldehyde and Citral.

ABSTRACT: This study was conducted to investigate the effects of in-feed encapsulated cinnamaldehyde (CIN) and citral (CIT) alone or in combination on antimicrobial resistance (AMR) phenotypes and genotypes of Escherichia coli isolates recovered from feces of 6-, 16-, 23-, and 27-day-old broiler chickens. The five dietary treatments including the basal diet (negative control [NC]) and the basal diet supplemented with 55 ppm of bacitracin (BAC), 100 ppm of encapsulated CIN, 100 ppm of encapsulated CIT, or 100 ppm each of encapsulated CIN and encapsulated CIT (CIN+CIT). Antimicrobial susceptibility testing of 240 E. coli isolates revealed that the most common resistance was to ß-lactams, aminoglycosides, sulfonamides, and tetracycline; however, the prevalence of AMR decreased (P < 0.05) as birds aged. The prevalence of resistance to amoxicillin-clavulanic acid, ceftiofur, ceftriaxone, cefoxitin, gentamicin, and sulfonamide was lower (P < 0.05) in isolates from the CIN or CIN+CIT groups than in isolates from the NC or BAC groups. Whole genome sequencing of 227 of the 240 isolates revealed 26 AMR genes and 19 plasmids, but the prevalence of some AMR genes and the number of plasmids were lower (P < 0.05) in E. coli isolated from CIN or CIN+CIT birds than in isolates from NC or BAC birds. The most prevalent resistance genes were tet(A) (108 isolates), aac(3)-VIa (91 isolates), aadA1 (86 isolates), blaCMY-2 (78 isolates), sul1 (77 isolates), aph(3)-Ib (58 isolates), aph(6)-Id (58 isolates), and sul2 (24 isolates). The numbers of most virulence genes carried by isolates increased (P < 0.05) in chickens from 6 to 27 days of age. The prevalence of E. coli O21:H16 isolates was lower (P < 0.05) in CIN and CIN+CIT, and the colibacillosis-associated multilocus sequence type (ST117) was most prevalent in isolates from 23-day-old chickens. A phylogenetic tree of whole genome sequences revealed a close relationship between 25 of the 227 isolates and human or broiler extraintestinal pathogenic E. coli strains. These findings indicate that AMR and virulence genotypes of E. coli could be modulated by providing encapsulated CIN or CIN+CIT feed supplements, but further investigation is needed to determine the mechanisms of the effects of these supplements.