Browsing by Author "Callaway, Todd"

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    Natural Antimicrobials Block the Host NF-κB Pathway and Reduce Enterocytozoon hepatopenaei Infection Both In Vitro and In Vivo
    (MDPI, 2023-07-20) Bundurus, Iulia Adelina; Balta, Igori; Butucel, Eugenia; Callaway, Todd; Popescu, Cosmin Alin; Iancu, Tiberiu; Pet, Ioan; Stef, Lavinia; Corcionivoschi, Nicolae; Animal Health and Welfare
    The objective of this work was to investigate, for the first time, the antioxidant effect of a mixture of natural antimicrobials in an Enterocytozoon hepatopenaei (EHP) shrimp-gut model of infection and the biological mechanisms involved in their way of action. The study approach included investigations, firstly, in vitro, on shrimp-gut primary (SGP) epithelial cells and in vivo by using EHP-challenged shrimp. Our results show that exposure of EHP spores to 0.1%, 0.5%, 1%, and 2% AuraAqua (Aq) significantly reduced spore activity at all concentrations but was more pronounced after exposure to 0.5% Aq. The Aq was able to reduce EHP infection of SGP cells regardless of cells being pretreated or cocultured during infection with Aq. The survivability of SGP cells infected with EHP spores was significantly increased in both scenarios; however, a more noticeable effect was observed when the infected cells were pre-exposed to Aq. Our data show that infection of SGP cells by EHP activates the host NADPH oxidases and the release of H2O2 produced. When Aq was used during infection, a significant reduction in H2O2 was observed concomitant with a significant increase in the levels of CAT and SOD enzymes. Moreover, in the presence of 0.5% Aq, the overproduction of CAT and SOD was correlated with the inactivation of the NF-κB pathway, which, otherwise, as we show, is activated upon EHP infection of SGP cells. In a challenge test, Aq was able to significantly reduce mortality in EHP-infected shrimp and increase the levels of CAT and SOD in the gut tissue. Conclusively, these results show, for the first time, that a mixture of natural antimicrobials (Aq) can reduce the EHP-spore activity, improve the survival rates of primary gut-shrimp epithelial cells and reduce the oxidative damage caused by EHP infection. Moreover, we show that Aq was able to stop the H2O2 activation of the NF-κB pathway of Crustins, Penaeidins, and the lysozyme, and the CAT and SOD activity both in vitro and in a shrimp challenge test.
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    The Prebiotic Effect of an Organic Acid Mixture on Faecalibacterium prausnitzii Metabolism and Its Anti-Pathogenic Role against Vibrio parahaemolyticus in Shrimp
    (MDPI, 2022-12-29) Butucel, Eugenia; Balta, Igori; McCleery, David; Marcu, Adela; Stef, Ducu; Pet, Ioan; Callaway, Todd; Stef, Lavinia; Corcionivoschi, Nicolae
    Increasing the abundance of probiotic bacteria in the gut requires either direct dietary supplementation or the inclusion of feed additives able to support the growth of beneficial commensal bacteria. In crustaceans, the increased presence of probiotic-like bacteria in the gut, including of Faecalibacterium prausnitzii (F. prausnitzii), will guarantee a positive health status and a gut environment that will ensure enhanced performance. The aim of this study was to investigate if a mixture of organic acids, AuraAqua (Aq) can stimulate the growth and the anti-pathogenic efficacy of F. prausnitzii through a combination of in vitro and ex vivo models. The results showed that 0.5% Aq was able to improve the growth rate of F. prausnitzii in vitro and in an ex vivo shrimp gut model. Moreover, we were able to demonstrate that Aq increases butyrate production and cellulose degradation in culture or in the shrimp gut model. The growth-stimulating effect of Aq also led to an improved and anti-pathogenic effect against Vibrio parahaemolyticus in a co-culture experiment with shrimp gut primary epithelial cells (SGP). In conclusion, our work demonstrates that Aq can stimulate the growth of F. prausnitzii, increase the production of short-chain fatty acid (SCFA) butyrate, improve substrate digestion, and prevent V. parahaemolyticus invasion of SGP cells.
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    A Review of the Effect of Management Practices on Campylobacter Prevalence in Poultry Farms
    (Frontiers Media, 2018-08-24) Sibanda, Nompilo; McKenna, Aaron; Richmond, Anne; Ricke, Steven C.; Callaway, Todd; Stratakos, Alexandros Ch.; Gundogdu, Ozan; Corcionivoschi, Nicolae
    Poultry is frequently associated with campylobacteriosis in humans, with Campylobacter jejuni being the most usual Campylobacter associated with disease in humans. Farreaching research on Campylobacter was undertaken over the past two decades. This has resulted in interventions being put in place on farms and in processing plants. Despite these interventions, coupled with increased media coverage to educate the consumer on Campylobacter prevalence and campylobacteriosis, human health incidents are still high. Recent research is now shifting toward further understanding of the microorganisms to challenge interventions in place and to look at further and more relevant interventions for the reduction in human incidents. Farm practices play a key role in the control of colonization within poultry houses and among flocks. Prevalence at the farm level can be up to 100% and time of colonization may vary widely between flocks. Considerable research has been performed to understand how farm management and animal health practices can affect colonization on farms. This review will focus on farm practices to date as a baseline for future interventions as the microorganism becomes better understood. Further research is required to understand the chicken microbiome and factors influencing vertical transmission. The persistence of Campylobacter in animal and environmental reservoirs within and around farms requires further investigation to tailor farm practices toward preventing such reservoirs. IMPLICATIONS This review gives an overview of farm practices and their effect on Campylobacter prevalence in poultry. Various elements of farm practices have been captured in this review.