@article{gaghan_gorrell_taha-abdelaziz_sharif_kulkarni_2023, title={Intracloacal Inoculation of Broiler Chickens with Clostridium perfringens Strains: Evaluation of Necrotic Enteritis Disease Development and Lymphoid Immune Responses}, volume={11}, ISSN={["2076-2607"]}, url={https://doi.org/10.3390/microorganisms11030771}, DOI={10.3390/microorganisms11030771}, abstractNote={Necrotic enteritis (NE) is an economically important disease of chickens. We have recently shown that inflammatory responses in chickens inoculated orally with virulent Clostridium perfringens were spatially regulated. Here, we used previously virulence-characterized netB+ C. perfringens strains, avirulent CP5 and virulent CP18 and CP26, to assess the severity of NE and immune responses in broiler chickens when inoculated intracloacally. The results showed that CP18- and CP26-infected birds had a reduced weight gain and developed milder/less severe NE lesions, as determined by the gross lesions scores, suggesting a subclinical-grade infection. Gene expression analysis in infected birds revealed three statistically significant observations compared to uninfected-control: (1) Increased expression of anti-inflammatory/immunoregulatory interleukin (IL)-10/transforming growth factor (TGF)β in cecal tonsil (CT) and bursa of Fabricius in the CP18/CP26-infected groups. (2) Increased CT transcription of pro-inflammatory IL-1β, IL-6 and interferon (IFN)γ and decreased Harderian gland (HG) expression of IFNγ in the CP18/CP26-infected birds. (3) Increased HG or bursal expression of IL-4 and IL-13 in CP5-infected birds. Collectively, intracloacal C. perfringens inoculation seems to induce a highly regulated inflammatory response in the CT and other mucosal lymphoid organs and an intracloacal infection model may be useful in evaluating immune responses in chickens with subclinical NE.}, number={3}, journal={MICROORGANISMS}, author={Gaghan, Carissa and Gorrell, Kaitlin and Taha-Abdelaziz, Khaled and Sharif, Shayan and Kulkarni, Raveendra R.}, year={2023}, month={Mar} }
 @article{kulkarni_gaghan_gorrell_fletcher_2023, title={Mucosal and systemic lymphoid immune responses against Clostridium perfringens strains with variable virulence in the production of necrotic enteritis in broiler chickens}, volume={1}, ISSN={["1465-3338"]}, DOI={10.1080/03079457.2022.2154195}, abstractNote={ABSTRACT Necrotic enteritis (NE), caused by Clostridium perfringens, is an economically important disease of chickens. Although NE pathogenesis is moderately well studied, the host immune responses against C. perfringens are poorly understood. The present study used an experimental NE model to characterize lymphoid immune responses in the caecal tonsils (CT), bursa of Fabricius, Harderian gland (HG) and spleen tissues of broiler chickens infected with four netB+ C. perfringens strains (CP1, CP5, CP18, and CP26), of which CP18 and CP26 strains also carried the tpeL gene. The gross and histopathological lesions in chickens revealed CP5 to be avirulent, while CP1, CP18, and CP26 strains were virulent with CP26 being “very virulent”. Gene expression analysis showed that, while the virulent strains induced a significantly upregulated expression of pro-inflammatory IL-1β gene in CT, the CP26-infected birds had significantly higher CT transcription of IFNγ and IL-6 pro-inflammatory genes compared to CP5-infected or uninfected chickens. Furthermore, CP26 infection also led to significantly increased bursal and HG expression of the anti-inflammatory/regulatory genes, IL-10 or TGFβ, compared to control, CP5 and CP1 groups. Additionally, the splenic pro- and anti-inflammatory transcriptional changes were observed only in the CP26-infected chickens. An antibody-mediated response, as characterized by increased IL-4 and/or IL-13 transcription and elevated IgM levels in birds infected with virulent strains, particularly in the CP26-infected group compared to uninfected controls, was also evident. Collectively, our findings suggest that lymphoid immune responses during NE in chickens are spatially regulated such that the inflammatory responses against C. perfringens depend on the virulence of the strain.}, journal={AVIAN PATHOLOGY}, author={Kulkarni, Raveendra R. and Gaghan, Carissa and Gorrell, Kaitlin and Fletcher, Oscar J.}, year={2023}, month={Jan} }
 @misc{kulkarni_gaghan_gorrell_sharif_taha-abdelaziz_2022, title={Probiotics as Alternatives to Antibiotics for the Prevention and Control of Necrotic Enteritis in Chickens}, volume={11}, ISSN={["2076-0817"]}, url={https://doi.org/10.3390/pathogens11060692}, DOI={10.3390/pathogens11060692}, abstractNote={Necrotic enteritis (NE) in poultry is an economically important disease caused by Clostridium perfringens type A bacteria. A global trend on restricting the use of antibiotics as feed supplements in food animal production has caused a spike in the NE incidences in chickens, particularly in broiler populations. Amongst several non-antibiotic strategies for NE control tried so far, probiotics seem to offer promising avenues. The current review focuses on studies that have evaluated probiotic effects on C. perfringens growth and NE development. Several probiotic species, including Lactobacillus, Enterococcus, Bacillus, and Bacteroides bacteria as well as some yeast species have been tested in chickens against C. perfringens and NE development. These findings have shown to improve bird performance, reduce C. perfringens colonization and NE-associated pathology. The underlying probiotic mechanisms of NE control suggest that probiotics can help maintain a healthy gut microbial balance by modifying its composition, improve mucosal integrity by upregulating expression of tight-junction proteins, and modulate immune responses by downregulating expression of inflammatory cytokines. Collectively, these studies indicate that probiotics can offer a promising platform for NE control and that more investigations are needed to study whether these experimental probiotics can effectively prevent NE in commercial poultry operational settings.}, number={6}, journal={PATHOGENS}, publisher={MDPI AG}, author={Kulkarni, Raveendra R. and Gaghan, Carissa and Gorrell, Kaitlin and Sharif, Shayan and Taha-Abdelaziz, Khaled}, year={2022}, month={Jun} }