Improving gut function in pigs to prevent pathogen colonization

Intestinal pathogens causing either clinical or sub-clinical infections increase pig morbidity and (or) mortality, resulting in economic losses and wider socio-economic impacts on pig production. An optimally functioning gastrointestinal tract (GIT) is fundamental to combatting intestinal pathogen colonisation at all the stages of life. This requires successful development and maintenance of key gut functions: digestive function; the gastro-intestinal cell line barrier; gut-associated lymphoid tissue (GALT); and gut-associated microbiota. This chapter first discusses research on genes associated with pathogen resistance and porcine immune response. It then reviews risk factors associated with gut mucosa impairment as well as dietary strategies to control risk factors and improve gut functionality in preventing intestinal pathogen colonisation.

Innovative Treatments Enhancing the Functionality of Gut Microbiota to Improve Quality and Microbiological Safety of Foods of Animal Origin

The gastrointestinal tract, or gut, microbiota is a microbial community containing a variety of microorganisms colonizing throughout the gut that plays a crucial role in animal health, growth performance, and welfare. The gut microbiota is closely associated with the quality and microbiological safety of foods and food products originating from animals. The gut microbiota of the host can be modulated and enhanced in ways that improve the quality and safety of foods of animal origin. Probiotics—also known as direct-fed microbials—competitive exclusion cultures, prebiotics, and synbiotics have been utilized to achieve this goal. Reducing foodborne pathogen colonization in the gut prior to slaughter and enhancing the chemical, nutritional, or sensory characteristics of foods (e.g., meat, milk, and eggs) are two of many positive outcomes derived from the use of these competitive enhancement–based treatments in food-producing animals. Expected final online publication date for the Annual Review of Food Science and Technology, Volume 13 is March 2022. Please see http://www.annualreviews.org/page/journal/pubdates for revised estimates.

Distinct N and C cross-feeding networks in a synthetic mouse gut consortium

The complex interactions between gut microbiome and host or pathogen colonization resistance cannot solely be understood from community composition. Missing are causal relationships such as metabolic interactions among species to better understand what shapes the microbiome. Here, we focused on metabolic niches generated and occupied by the Oligo-Mouse-Microbiota consortium, a synthetic community composed of 12 members that is increasingly used as a model for the mouse gut microbiome. Combining mono-cultures and spent medium experiments with untargeted metabolomics uncovered broad metabolic diversity in the consortium, constituting a dense cross-feeding network with more than 100 pairwise interactions. Quantitative analysis of the cross-feeding network revealed distinct C and N food webs that highlight the two Bacteroidetes consortium members B. caecimuris and M. intestinale as primary suppliers of carbon, and a more diverse group as nitrogen providers. Cross-fed metabolites were mainly carboxylic acids, amino acids, and the so far not reported nucleobases. In particular the dicarboxylic acids malate and fumarate provided a strong physiological benefit to consumers, presumably as anaerobic electron acceptors. Isotopic tracer experiments validated the fate of a subset of cross-fed metabolites, in particular the conversion of the most abundant cross-fed compound succinate to butyrate. Thus, we show that this consortium is tailored to produce the anti-inflammatory metabolite butyrate. Overall, we provide evidence for metabolic niches generated and occupied by OMM members that lays a metabolic foundation to facilitate understanding of the more complex in vivo behavior of this consortium in the mouse gut.

Orchestrating a heist: uptake and storage of metals by apicomplexan parasites

The acquisition and storage of metals has been a preoccupation of life for millennia. Transition metals, in particular iron, copper and zinc, have vital roles within cells. However, metals also make dangerous cargos; inappropriate uptake or storage of transition metals leads to cell death. This paradox has led to cells developing elegant and frequently redundant mechanisms for fine-tuning local metal concentrations. In the context of infection, pathogens must overcome further hurdles, as hosts act to weaponize metal availability to prevent pathogen colonization and spread. Here, we detail the methods used by the Apicomplexa, a large family of eukaryotic parasites, to obtain and store essential metals.

Managing Gut Microbiota through In Ovo Nutrition Influences Early-Life Programming in Broiler Chickens

The chicken gut is the habitat to trillions of microorganisms that affect physiological functions and immune status through metabolic activities and host interaction. Gut microbiota research previously focused on inflammation; however, it is now clear that these microbial communities play an essential role in maintaining normal homeostatic conditions by regulating the immune system. In addition, the microbiota helps reduce and prevent pathogen colonization of the gut via the mechanism of competitive exclusion and the synthesis of bactericidal molecules. Under commercial conditions, newly hatched chicks have access to feed after 36–72 h of hatching due to the hatch window and routine hatchery practices. This delay adversely affects the potential inoculation of the healthy microbiota and impairs the development and maturation of muscle, the immune system, and the gastrointestinal tract (GIT). Modulating the gut microbiota has been proposed as a potential strategy for improving host health and productivity and avoiding undesirable effects on gut health and the immune system. Using early-life programming via in ovo stimulation with probiotics and prebiotics, it may be possible to avoid selected metabolic disorders, poor immunity, and pathogen resistance, which the broiler industry now faces due to commercial hatching and selection pressures imposed by an increasingly demanding market.

INFLUENCE OF PATIENT’S GENERAL HEALTH STATUS ON THE OUTCOME OF INFECTIONS

The outcomes of a pathogen colonization and development of clinical infection can be strictly related to the general health status of a patient. The spread of the awareness about the dangers of underlying health conditions should be the main role of the conventional medicine, as well as the key to successful treatments and control of diseases.

Evaluasi Cendawan Endofit Asal Tanaman Karet untuk Mengendalikan Colletotrichum gloeosporioides Patogen Penyakit Gugur Daun Colletotrichum

<p><em>Colletotrichum leaf fall disease caused by </em>Colletotrichum gloeosporioides<em> is an important disease in rubber plants. The </em>C. gloeosporioides<strong><em> </em></strong><em>Infection can reduce production by 7%-45%. Controlling the pathogen using endophytic fungi is very promising because it can suppress inoculum and pathogen colonization, induce plant resistance, and trigger plant growth. The study aimed to evaluate the endophytic fungus isolate from rubber to control </em>C. gloeosporioides<strong><em> </em></strong><em>as a pathogen that caused the rubber leaf fall disease. This research was carried out in the laboratory and greenhouse of the Indonesian Industrial and Beverage Crop Research Institute (IIBCRI), Sukabumi, from March to November 2018. The isolates used were endophytic fungi isolates from rubber plants, which were tested for their inhibition against </em>C. gloeosporioides<em> in vitro on rubber leaves and seedlings, and their mechanism. The variable observed were the inhibition rate, incubation periods, number of spots, disease severity, and plant growth. The results showed that the endophytic fungus could inhibit the growth of </em>C. gloeosporioides<em> about 64.17% - 86.67%. The high inhibitory activity (&gt;80%) in isolates CEPR.19, CEPR.6, CEBPM.21, DTJE.1, and DMJE27 were 86.67%; 83.33%; 83.33%; 82.92%, and 82.50%, respectively. The observations on seedlings obtained three potential fungal isolates to control </em>C. gloeosporioides<em> on rubber leaves, namely CEBPM.21, CEPR19, and DTJE.1 with suppression of disease severity about 68.57%; 67.88%, and 60.20% with their mechanisms of action inducing resistance, antibiosis, competition, and hyperparasites.</em><em></em></p>

Microbiota from Specific Pathogen-Free Mice Reduces Campylobacter jejuni Chicken Colonization

Campylobacter jejuni, a prevalent foodborne bacterial pathogen, is mainly transmitted from poultry with few effective prevention approaches. In this study, we aimed to investigate the role of microbiota on C. jejuni chicken colonization. Microbiota from specific pathogen-free (SPF) mouse stools were collected as SPF-Aerobe and SPF-Anaerobe. Birds were colonized with SPF-Aerobe or SPF-Anaerobe at day 0 and infected with C. jejuni AR101 at day 12. Notably, C. jejuni AR101 colonized at 5.3 and 5.6 log10 C. jejuni CFU/g chicken cecal digesta at days 21 and 28, respectively, while both SPF-Aerobe and SPF-Anaerobe microbiota reduced pathogen colonization. Notably, SPF-Aerobe and SPF-Anaerobe increased cecal phylum Bacteroidetes and reduced phylum Firmicutes compared to those in the nontransplanted birds. Interestingly, microbiota from noninfected chickens, SPF-Aerobe, or SPF-Anaerobe inhibited AR101 in vitro growth, whereas microbiota from infected birds alone failed to reduce pathogen growth. The bacterium Enterobacter102 isolated from infected birds transplanted with SPF-Aerobe inhibited AR101 in vitro growth and reduced pathogen gut colonization in chickens. Together, SPF mouse microbiota was able to colonize chicken gut and reduce C. jejuni chicken colonization. The findings may help the development of effective strategies to reduce C. jejuni chicken contamination and campylobacteriosis.

Efficacy of Chemical and Biological Stump Treatments for the Control of Heterobasidion occidentale Infection of California Abies concolor

We conducted an experimental evaluation of treatments to limit Heterobasidion occidentale infection of white fir (Abies concolor) stumps and wounds in California mixed conifer forests. We tested the efficacy of urea, borate, and a mixture of two locally collected Phlebiopsis gigantea strains in preventing pathogen colonization of fir stumps and separately, urea and borate as infection controls on experimental stem wounds. These were paired with a laboratory test on ~100 g wood blocks with and without a one-week delay between inoculation and treatment. Urea, borates, and Phlebiopsis treatments all significantly reduced the stump surface area that was colonized by H. occidentale at 84%, 91%, and 68%, respectively, relative to the controls. However, only the borate treatments significantly lowered the number of stumps that were infected by the pathogen. The laboratory study matched the patterns that were found in the stump experiment with a reduced area of colonization for urea, borates, or P. gigantea treatments relative to the controls; delaying the treatment did not affect efficacy. The field wound experiment did not result in any Heterobasidion colonization, even in positive control treatments, rendering the experiment uninformative. Our study suggests treatments that are known to limit Heterobasidion establishment on pine or spruce stumps elsewhere in the world may also be effective on true firs in California.

The Gut Microbiota of Newborn Calves and Influence of Potential Probiotics on Reducing Diarrheic Disease by Inhibition of Pathogen Colonization

Calf diarrhea is one of the most concerning challenges facing both the dairy and beef cattle industry. Maintaining healthy gut microbiota is essential for preventing gastrointestinal disorders. Here, we observed significantly less bacterial richness in the abnormal feces with watery or hemorrhagic morphology compared to the normal solid feces. The normal solid feces showed high relative abundances of Osllospiraceae, Christensenellaceae, Barnesiella, and Lactobacillus, while the abnormal feces contained more bacterial taxa of Negativicutes, Tyzzerella, Parasutterella, Veillonella, Fusobacterium, and Campylobacter. Healthy calves had extensive bacterial-bacterial correlations, with negative correlation between Lactobacillus and potential diarrheagenic Escherichia coli-Shigella, but not in the abnormal feces. We isolated Lactobacillus species (L. reuteri, L. johnsonii, L. amylovorus, and L. animalis), with L. reuteri being the most abundant, from the healthy gut microbiota. Isolated Lactobacillus strains inhibited pathogenic strains including E. coli K88 and Salmonella Typhimurium. These findings indicate the importance of a diverse gut microbiota in newborn calf’s health and provide multiple potential probiotics that suppress pathogen colonization in the gastrointestinal tract to prevent calf diarrhea.