Cost-effectiveness analysis of using probiotics, prebiotics, or synbiotics to control Campylobacter in broilers

Current evidence of the economic value of One Health initiatives: A systematic literature review

Funding and financing for One Health initiatives at country level remain challenging as investments commonly require demonstrated evidence of economic value or returns. The objectives of this review were to i) identify, critically analyse and summarise quantitative evidence of the net economic value of One Health initiatives; ii) document methodologies commonly used in the scientific literature; and iii) describe common challenges and any evidence gaps. Scientific databases were searched for published literature following the PRISMA guidelines and an online survey and workshop with subject matter experts were used to identify relevant grey literature. Studies were included if they reported on quantitative costs and benefits (monetary and non-monetary) and were measured across at least two sectors. Relevant publications were analysed and plotted against the six action tracks of the Quadripartite One Health Joint Plan of Action to help classify the initiatives. Ninety-seven studies were included. Eighty studies involved only two sectors and 78 reported a positive economic value or return. Of those studies that reported a positive return, 49 did not compare with a sectoral counterfactual, 28 studies demonstrated an added value of using a cross-sectoral approach, and 6 studies demonstrated an added value of One Health communication, collaboration, coordination, and capacity building. Included studies most frequently related to endemic zoonotic, neglected tropical and vector-borne diseases, followed by health of the environment and food safety. However, diversity in economic analysis methodology between studies included resulted in difficulty to compare or combine findings. While there is a growing body of evidence of the value of One Health initiatives, a substantial part of the evidence still focuses on "traditional" One Health topics, particularly zoonoses. Developing a standardised and practical approach for One Health economic evaluation will facilitate assessment of the added value and gather evidence for One Health to be invested in and endorsed by multiple sectors.

Assessment of probiotic Bacillus velezensis supplementation to reduce Campylobacter jejuni colonization in chickens

Campylobacter jejuni continues to be a major public health issue worldwide. Poultry are recognized as the main reservoir for this foodborne pathogen. Implementing measures to decrease C. jejuni colonization on farms has been regarded as the most effective strategy to control the incidence of campylobacteriosis. The probiotics supplementation has been regarded as an attractive approach against C. jejuni in chickens. Here the inhibitory effects of one probiotic B. velezensis isolate CAU277 against C. jejuni was evaluated in vitro and in vivo. The in vitro antimicrobial activity showed that the supernatant of B. velezensis exhibited the most pronounced inhibitory effects on Campylobacter strains compared to other bacterial species. When co-cultured with B. velezensis, the growth of C. jejuni reduced significantly from 7.46 log10 CFU/mL (24 h) to 1.02 log10 CFU/mL (48 h). Further, the antimicrobial activity of B. velezensis against C. jejuni remained stable under a broad range of temperature, pH, and protease treatments. The in vivo experiments demonstrated that oral administration of B. velezensis significantly reduced the colonization of C. jejuni by 2.0 log10 CFU/g of feces in chicken cecum at 15 d postinoculation. In addition, the supplementary of B. velezensis significantly increased microbial species richness and diversity in chicken ileum, especially enhanced the bacterial population of Alistipes and Christensenellaceae, and decreased the existence of Lachnoclostridium. Our study presents that B. velezensis possesses antimicrobial activities against C. jejuni and promotes microbiota diversity in chicken intestines. These findings indicate a potential to develop an effective probiotic additive to control C. jejuni infection in chicken.

Emerging in ovo technologies in poultry production and the re-discovered chicken model in preclinical research

Prenatal programming is a concept based on assumptions that the events occurring in critical points of embryonic development may pose epigenetic changes resulting from chemical rearrangements on the DNA structure. Epigenetic changes may pose life lasting phenotypic effects in the animal, or can be heritable, like gene silencing associated with methylation in gene promoters regions. The technical advancements in biotechnology, bioinformatics, molecular techniques and robotization have brought to new technological applications in poultry production. Intentional stimulation of embryonic development and determination of the future health of the hatched organism is possible by in ovo application of natural antioxidants and prebiotics, gut stabilizers like probiotics and other immunological enhancements, including vaccines. In parallel, the fine-tuned and generally accessible techniques of chicken embryo incubation along with the novel tissue engineering tools have led to focus the attention of scientists on chicken embryo as the alternative animal model for some pre-clinical approaches, in the context of reducing and replacing the experiments on animals. In this chapter, some key highlights are provided on current achievements in poultry embryonic applications, with the attention put to the emerging in ovo technologies (in ovo feeding, immunological stimulation and in ovo oncological tools), that address the societal challenges in food production and health management.

Clostridium butyricum alleviates LPS-induced acute immune stress in goats by regulating bacterial communities and blood metabolites

The mitigation and prevention of acute immune stress are essential for livestock production. Clostridium butyricum (C. butyricum) has shown positive effects in stabilizing intestinal microbiota disorders, improving immune function and inhibiting disease development, but its effects on ruminants are unclear. Therefore, the current trial hypothesized that C. butyricum could improve goats' immune function and antioxidant capacity by regulating bacterial communities and blood metabolism and effectively alleviating the acute immune stress induced by Lipopolysaccharides (LPS). Sixteen healthy goats were fed C. butyricum for 70 days, and the goats were challenged with LPS on day 71. Blood and feces were collected at 0 h and 6 h after the challenge to evaluate the effects of C. butyricum on their intestinal microbiota, immune function, antioxidant function, and plasma metabolites. The results showed that C. butyricum had no significant effect on plasma biochemical parameters at the beginning of the LPS challenge. However, supplementation with C. butyricum increased plasma levels of IgA, IgG, T-SOD, and T-AOC (P < 0.05), but TNF-α, IL-6, and MDA were decreased (P < 0.05). In contrast, IL-10 showed an increasing trend (P < 0.10). Rectal microbiota analysis showed that C. butyricum significantly increased the relative abundance of Epsilonbacteraeota at the phylum level of goats; at the genus level, the relative abundances of Campylobacter and Anaerorhabdus]_furcosa_group were also significantly increased (P < 0.05). Christensenellaceae_R-7_group as the dominant microbiota also showed a significant increase in their abundance values, while Clostridium and Lachnospiraceae_UCG-001 were significantly lower (P < 0.05). When the LPS challenge continued up to 6 h, dietary supplementation with C. butyricum still resulted in significantly higher plasma concentrations of IgA, IL-10, and T-SOD in goats than in the control group, reducing TNF-α levels (P < 0.05). In addition, plasma levels of T-CHOL and LDL were significantly reduced, and the expression of d-proline was significantly upregulated according to metabolomic analysis (P < 0.05). In conclusion, dietary supplementation with C. butyricum helped optimize the expression of bacterial communities and plasma metabolites to enhance the ability of goats to alleviate acute immune stress.

The effect of Escherichia coli ŽP strain with a conjugation-based colicin E7 delivery on growth performance, hematological, biochemical, and histological parameters, gut microbiota, and nonspecific immunity of broilers

The Escherichia coli ŽP strain (ŽP) was constructed based on the known probiotic E. coli strain Nissle 1917. It was genetically modified to carry the colicin E7 synthesis gene encoding DNase on a conjugative plasmid and the colicin E7 immunity gene in the chromosome. The aim of this study was to evaluate the effects of the daily ŽP per oral administration (5 × 10⁸ or 5 × 10¹⁰ CFU per bird) on the growth performance, hematological, biochemical, histological parameters, gut microbiota, and nonspecific immunity of the 4-24 days old broilers. The ŽP administration increased the abundance of genera Bacillus, Butyrivibrio, and Clostridium and did not influence the weight gain of 4-16 days old broilers. The biochemical parameters were within normal ranges for poultry in experimental and control groups. The ŽP administration had no effect on the erythrocyte numbers, hemoglobin and immunoglobulin Y concentrations, but significantly increased the serum lysozyme concentration, leukocyte numbers, and reactive oxygen species production by phagocytes compared with the control group. It did not cause inflammatory changes in intestinal mucosa, Peyer's patches, and spleen. Thus, the ŽP had no detrimental effects on broiler health and could be an efficient probiotic for the broiler colibacillosis prophylaxis.

Bacillus subtilis PS-216 Spores Supplemented in Broiler Chicken Drinking Water Reduce Campylobacter jejuni Colonization and Increases Weight Gain

Campylobacter jejuni is the leading cause of bacterial gastroenteritis, or campylobacteriosis, in humans worldwide, and poultry serves as a major source of infection. To reduce the risk associated with C. jejuni transmission via poultry meat, effective interventions during poultry production are needed, and the use of probiotics is a promising approach. In this study, 15 Bacillus subtilis strains were initially screened for their anti-Campylobacter activities. B. subtilis PS-216 strain demonstrated the best anti-Campylobacter activity against 15 C. jejuni isolates when examined using in vitro co-cultures. To evaluate the suitability of B. subtilis PS-216 for probiotic use, its susceptibility to eight clinically important antimicrobials and simulated gastric conditions was investigated. B. subtilis PS-216 was sensitive to all of the tested antibiotics. Although vegetative cells were sensitive to gastric conditions, B. subtilis PS-216 spores were highly resistant. We further evaluated the use of a B. subtilis PS-216 spore preparation (2.5 × 106 CFU/mL water) to prevent and/or reduce C. jejuni colonization in broiler chickens in vivo. Compared to the untreated group, significantly lower Campylobacter counts were detected in caeca of broilers continuously treated with B. subtilis PS-216 spores in their drinking water. Furthermore, broilers continuously treated with B. subtilis PS-216 spores showed improved weight gain, compared to the control group. Together, these results demonstrate the potential of B. subtilis PS-216 for use in poultry to reduce C. jejuni colonization and improve weight gain.

In Vitro Demonstration of Targeted Phage Therapy and Competitive Exclusion as a Novel Strategy for Decolonization of Extended-Spectrum-Cephalosporin-Resistant Escherichia coli

Extended-spectrum cephalosporin-resistant (ESC-R) Escherichia coli have disseminated in food-producing animals globally, attributed to horizontal transmission of bla_CTX-M variants, as seen in the InCI1-bla_CTX-M-1 plasmid. This ease of transmission, coupled with its demonstrated long-term persistence, presents a significant One Health antimicrobial resistance (AMR) risk. Bacteriophage (phage) therapy is a potential strategy in eliminating ESC-R E. coli in food-producing animals; however, it is hindered by the development of phage-resistant bacteria and phage biosafety concerns. Another alternative to antimicrobials is probiotics, with this study demonstrating that AMR-free commensal E. coli, termed competitive exclusion clones (CECs), can be used to competitively exclude ESC-R E. coli. This study isolated and characterized phages that lysed E. coli clones harboring the InCI1-bla_CTX-M-1 plasmid, before investigation of the effect and synergy of phage therapy and competitive exclusion as a novel strategy for decolonizing ESC-resistant E. coli. In vitro testing demonstrated superiority in the combined therapy, reducing and possibly eliminating ESC-R E. coli through phage-mediated lysis coupled with simultaneous prevention of regrowth of phage-resistant mutants due to competitive exclusion with the CEC. Further investigation into this combined therapy in vivo is warranted, with on-farm application possibly reducing ESC-R prevalence, while constricting newly emergent ESC-R E. coli outbreaks prior to their dissemination throughout food-producing animals or humans. IMPORTANCE The emergence and global dissemination of resistance toward critically important antimicrobials, including extended-spectrum cephalosporins in the livestock sector, deepens the One Health threat of antimicrobial resistance. This resistance has the potential to disseminate to humans, directly or indirectly, nullifying these last lines of defense in life-threatening human infections. This study explores a novel strategy, the coadministration of bacteriophages (phages) and a competitive exclusion clone (antimicrobial-susceptible commensal E. coli), to revert an antimicrobial-resistant population to a susceptible population. While phage therapy is vulnerable to the emergence of phage-resistant bacteria, no phage-resistant bacteria emerged when a competitive exclusion clone was used in combination with the phage. Novel strategies that reduce the prevalence and slow the dissemination of extended-spectrum cephalosporin-resistant E. coli in food-producing animals have the potential to extend the time frame in which antimicrobials remain available for effective use in animal and human health.

Innovative hurdle system towards Listeria monocytogenes inactivation in a fermented meat sausage model - high pressure processing assisted by bacteriophage P100 and bacteriocinogenic Pediococcus acidilactici

Consumers' quest for healthier, locally produced foods, renders the demand for these products increasingly prominent. The purpose of the present work was to evaluate the impact of a non-thermal multi-hurdle approach, which associated mild high hydrostatic pressure (HHP, 300 MPa), the bacteriophage Listex™ P100, and the pediocin PA-1 producing Pediococcus acidilactici HA 6111-2, as a novel minimal processing towards Listeria monocytogenes eradication in Alheira (a traditional fermented meat sausage from Northern Portugal). The combination of the three hurdles achieved the USDA-FSIS 5 log reduction (in accordance with the standard guidelines for ready-to-eat foods), being the only treatment to elicit the absence of L. monocytogenes immediately following processing (p < 0.05). The pair association of HHP with Listex™ P100 was unable to eliminate L. monocytogenes, whilst in the HHP-pediocin PA-1 producing P. acidilactici treated samples the eradication was delayed when compared to the three hurdles combination. In addition to the listericidal effect of the HHP-phage-lactic acid bacterium treatment, no significant differences (p > 0.05) in the pH values were observed, and the semi-quantification of the in situ biosynthesized pediocin PA-1 was documented for the first time in a fermented meat sausage model.

RNA-Seq transcriptome analysis of ileum in Taiping chicken supplemented with the dietary probiotic

Taiping chicken is indigenous chickens (Gallus gallus domesticus), which was one of China's excellent poultry species. As the problems caused by the overuse of antibiotics become more and more concern, people begin to look for ways to replace them. Among them, probiotics and their preparations are the research hotspot to replace antibiotics. Probiotics can promote the absorption of nutrients, improve the ratio of meat to meat, resist and prevent diseases, and improve the intestinal tissue morphology. Here, we performed transcriptome profiling of Taiping chicken ileum which was given probiotics by using the Hiseq™ 2500 sequencing platform. A total of 18 genes were differentially expressed in the ileum under control group and probiotics group. Thirteen genes were upregulated with a range of fold change from 1.02 to 8.61, and 5 were downregulated with a range of fold change from - 1.06 to - 2.29. Ten of the differently expressed genes were further validated by qRT-PCR. In addition, Gene ontology and Kyoto Encyclopedia of Genes and Genomes analyses revealed that these differentially expressed genes were mainly enriched to bile secretion, alpha-linolenic acid metabolism, linoleic acid metabolism, ether lipid metabolism, and arachidonic acid metabolism. This study will help us to understand the role of probiotics in indigenous chicken production and provide theoretical basis for the genetic development of indigenous chickens.

Serotonin modulates Campylobacter jejuni physiology and invitro interaction with the gut epithelium

Microbial endocrinology, which is the study of neurochemical-based host–microbe interaction, has demonstrated that neurochemicals affect bacterial pathogenicity. A variety of neurochemicals, including norepinephrine, were shown to enhance intestinal epithelial colonization by Campylobacter jejuni. Yet, little is known whether serotonin, an abundant neurochemical produced in the gut, affects the physiology of C. jejuni and its interaction with the host gut epithelium. Considering the avian gut produces serotonin and serves as a major reservoir of C. jejuni, we sought to investigate whether serotonin can affect C. jejuni physiology and gut epithelial colonization in vitro. We first determined the biogeographical distribution of serotonin concentrations in the serosa, mucosa, as well as the luminal contents of the broiler chicken ileum, cecum, and colon. Serotonin concentrations were greater (P < 0.05) in the mucosa and serosa compared to the luminal content in each gut region examined. Among the ileum, colon, and cecum, the colon was found to contain the greatest concentrations of serotonin. We then investigated whether serotonin may effect changes in C. jejuni growth and motility in vitro. The C. jejuni used in this study was previously isolated from the broiler chicken ceca. Serotonin at concentrations of 1mM or below did not elicit changes in growth (P > 0.05) or motility (P > 0.05) of C. jejuni. Next, we utilized liquid chromatography tandem mass spectrometry to investigate whether serotonin affected the proteome of C. jejuni. Serotonin caused (P < 0.05) the downregulation of a protein (CJJ81176_1037) previously identified to be essential in C. jejuni colonization. Based on our findings, we evaluated whether serotonin would cause a functional change in C. jejuni adhesion and invasion of the HT29MTX-E12 colonic epithelial cell line. Serotonin was found to cause a reduction in adhesion (P < 0.05) but not invasion (P > 0.05). Together, we have identified a potential role for serotonin in modulating C. jejuni colonization in the gut in vitro. Further studies are required to understand the practical implications of these findings for the control of C. jejuni enteric colonization in vivo.