About

Sarah Ho is the CVM Director of Student Engagement at the College of Veterinary Medicine at NC State University. Her role involves fostering student involvement and supporting their academic and personal growth within the college community. The page emphasizes her position in enhancing the student experience, but it does not provide specific details about her research focus, background, or key contributions in the field of veterinary medicine or biomedical sciences.

Research topics

• Immunology
• Biology
• Microbiology
• Virology
• Biochemistry
• Animal science
• Food science
• Andrology

Selected publications

• Clostridium septicum Alpha Toxin-Based Recombinant Subunit Vaccine Protects Broiler Chickens Against Clostridial Dermatitis

  Avian Diseases · 2026-02-16

  articleSenior author

  induced CD and that the mechanisms of protection seem to operate through anti-ATX antibodies coupled with modulation of local and systemic inflammatory as well as cellular immune responses.

  PublisherDOI

• Evaluating the Effect of Acetylsalicylic Acid in Turkey Poults Experimentally Infected with Coccidia

  Avian Diseases · 2026-03-05

  article

  Acetylsalicylic acid (ASA), originally trademarked as Aspirin, is a common nonsteroidal anti-inflammatory drug (NSAID) used in human and veterinary medicine to mitigate pain and pyrexia caused by inflammatory processes. There is limited information on the effectiveness of ASA in turkey production. The objective of this study was to investigate the effect of ASA on turkey poults with induced coccidial enteritis. Two experimental trials were conducted. In both trials, the turkeys were divided into four groups: no coccidia + no ASA; no coccidia + ASA (NA); coccidia + no ASA (CN); and coccidia + ASA (CA). In both trials, turkeys in groups CN and CA were given 100× the dose of a commercial turkey coccida vaccine. Starting 48 hr postinoculation and for 7 days, the turkeys from groups NA and CA were given ASA (50 mg/kg per day). For Trial 1, ASA was given via oral gavage twice daily, whereas in Trial 2 (T2), ASA was in the drinking water. Poult weights and cloacal temperatures were recorded daily. Blood was collected daily from two randomly selected birds from each group for biochemical analysis and to assess the serum salicylic acid and nitric oxide (NO) levels. At the end of the trials, tissues were examined histologically, and immune gene expression was evaluated. Coccidia infection was the factor that had most significant influence on the majority of measured parameters. ASA had minimal to no effect on reducing clinical signs, minimizing weight loss, or controlling body temperature. These findings may be due to the rapid elimination of the drug or because sick birds did not consume sufficient ASA. In T2, it was estimated that the CA group poults consumed 31 mg/kg of ASA or less per day. Although the drinking water concentration was calculated to match the total daily intake (50 mg/kg per day), ASA's rapid metabolism meant that continuous low-level ingestion might not have reached the therapeutic plasma threshold achieved by two to three daily bolus doses. Because ASA is rapidly metabolized, a higher total daily dose may be required when provided in drinking water to maintain effective serum concentrations compared with bolus administration. Although the serum NO and tissue gene expression analysis showed that coccidia infection predominantly induces an inflammatory response, the anti-inflammatory effect of ASA administered to birds in the NA or CA groups were nil to minimal. This study highlights the complexity of ASA's effects on turkeys.

  PublisherDOI

• Effect of Green Tea (Camellia sinensis) Extract on Growth Performance, Intestinal Health, and Immune Response of Broiler Chickens During Subclinical Necrotic Enteritis

  Pathogens · 2025-03-06 · 3 citations

  articleOpen access

  This study evaluated the effects of varying levels of dietary green tea extract (GTE) on growth performance, Clostridium perfringens (CP) colonization, and inflammatory responses in broiler chickens during experimental subclinical necrotic enteritis (SNE). In a 21-day experiment, 480 one-day-old male broiler (Ross 708) chicks were equally allotted into four dietary treatment groups. From days 1 to 10, all groups received a corn–soy basal diet, switching to a wheat-fish diet on day 11. Treatments included CON (no GTE), GTX, GTY, and GTZ (250, 500, and 1000 mg/kg GTE, respectively). On day 11, each group split into ACON, AGTX, AGTY, and AGTZ, totaling eight treatments. From days 17 to 20, ACON, AGTX, AGTY, and AGTZ chicks were orally challenged twice daily with 3 mL CP26 (2.5 × 108 CFU/mL). On d 16 (pre-challenge) and d 1 post-challenge, ileo-jejunal contents were collected for CP enumeration, and jejunum tissue was analyzed via qRT-PCR to determine the expression levels of IL-1β, IFNγ, TNF-α, TGFβ, IL-10, and MUC2 genes. Challenged chicks showed poorer (p ≤ 0.05) growth and higher intestinal CP, with a potential improvement in GTE-supplemented diets. Findings suggests that dietary GTE supplementation mitigated the characteristic growth depression during SNE, reduced intestinal CP infection, and modulated inflammatory response in broiler chicks.

  PublisherOA PDFDOI

• Ability to accelerate innate and cell-mediated immune responses in meat-type chickens by in ovo vaccination with monovalent and bivalent Marek's disease vaccines

  Vaccine · 2025-11-21

  articleOpen accessCorresponding

  We have previously demonstrated that in ovo vaccination with Herpesvirus of Turkey (HVT) at 18 days-of-embryonation (ED) accelerates innate and cell-mediated immunity in one-day-old meat- and egg-type chickens. We also reported differences in the splenic immunophenotypes of egg-type chickens following HVT, CVI-988, and SB-1 vaccination. In this study, using meat-type chickens, we further evaluated the effect of in ovo administration of CVI-988 or SB-1 on innate and adaptive immune responses when compared to HVT. Additionally, we also assessed the synergistic immunopotentiation effect, if any, of CVI-988 or SB-1 with HVT. Results showed that all three vaccines could significantly augment splenic frequencies of γδ T cells, CD4 + CD28 + , CD4 + CD44 + , CD8 + CD28 + , and CD8 + CD44 + T cells compared to sham-inoculated chickens. However, vaccines differed on tissue tropism, ability to increase PHA-L driven wing-web thickness, and ability to increase the frequency of some immunophenotypes. The frequencies of activated monocytes/macrophages, CD4 + CD8 + double-positive (DP) cells, and CD4 + MHC-II + cells were found significantly higher in SB-1 and HVT groups compared to sham-inoculated control. Additionally, SB-1 vaccination led to significantly increased frequency of CD4 + T cells compared to CVI-988 and control groups. Furthermore, in comparison to HVT, SB-1 induced significantly higher frequencies of activated monocytes/macrophages and DP cells, while the CVI-988 vaccination showed a significant reduction in DP cells, CD4 + CD28 + , and CD4 + CD44 + T cells. Finally, the synergistic effect of CVI-988 and HVT was observed in relation to augmenting splenic transcription of IFN-β and IFN-γ, while no effect on the changes in splenic immunophenotypes was observed. Collectively, all three vaccines (HVT, CVI-988 and SB-1) seem to enhance innate and/or adaptive responses in day-old meat-type chickens; however, immune-synergism of these vaccines needs further investigation.

  PublisherDOI

• Major Foodborne Bacterial Pathogens in Poultry: Implications for Human Health and the Poultry Industry and Probiotic Mitigation Strategies

  Microorganisms · 2025-10-14 · 13 citations

  reviewOpen access

  Poultry production has become the fastest-growing sector in global meat supply. However, the intensification of poultry farming has increased the risk of zoonotic transmission of bacterial pathogens such as Salmonella spp., Campylobacter spp., Escherichia coli, Clostridium perfringens, and Listeria monocytogenes. These bacterial agents pose major public health concerns, contributing to millions of human infections annually and substantial economic losses. Historically, antibiotic growth promoters (AGPs) were widely used to mitigate disease burden and improve poultry productivity. Yet, the global shift away from AGPs due to concerns over antimicrobial resistance has spurred interest in antimicrobial alternatives. Among these, probiotics have been explored as a promising preharvest intervention. This review investigates major bacterial foodborne pathogens associated with poultry and evaluates the practical implementation of probiotic-based strategies in modern poultry production systems, with the goal of reducing pathogen load and enhancing overall food safety.

  PublisherOA PDFDOI

• Protection Conferred by Gallid Alphaherpesvirus 2 Vaccines Against Immunosuppression Induced by Very Virulent Plus (vv+) Marek’s Disease Virus Strains in Commercial Meat Type Chickens

  Pathogens · 2025-01-10 · 3 citations

  articleOpen accessCorresponding

  Very virulent plus Marek's disease virus (vv+MDV) induces severe immunosuppression in commercial chickens. In this study, we evaluated how three Gallid alphaherpesvirus 2 (GaHV-2) vaccines (CVI-988, rMd5-BAC∆Meq, and CVI-LTR) protected against two negative outcomes of vv+MDV infection: (1) reduced viability and frequency of immune cells in the spleen and (2) decreased efficacy of the CEO (chicken embryo origin) vaccine against infectious laryngotracheitis challenge. At 25 days post-infection with vv+MDV 686, all vaccines are protected against the reduced viability of splenocytes. However, there were differences in the frequency of splenic immunophenotypes among groups. Compared to the uninfected control, the frequency of B cells was reduced in the CVI-988/686 group but not in the rMd5-BAC∆Meq/686 and CVI-LTR/686 groups. T cell subset frequencies showed no difference between the negative controls and CVI-988/686; however, there was a reduction in activated CD4+ T cells in the rMd5-BAC∆Meq/686 group and in activated CD4+, activated CD8+, and γδ+ T cells in the CVI-LTR/686 group. We also demonstrated that the three vaccines protected against MDV-induced tumors, but only rMd5-BAC∆Meq and CVI-LTR protected against the negative impact of vv+MDV 648A strain on CEO vaccine efficacy. Our findings demonstrate important differences in the biology and/or mechanisms of protection of these vaccines.

  PublisherOA PDFDOI

• Characterization of immunopathological changes in the feather pulp of CVI988-vaccinated pullets challenged with a very virulent plus Marek’s disease virus strain

  Avian Pathology · 2025-02-28

  article

  High load of oncogenic Marek's disease virus (MDV) DNA in the feather pulp (FP) as early as 21 days of age is a powerful criterion to predict the outcome of Marek's disease (MD) in apparently healthy chickens. The objective of this study was to elucidate the immunopathological changes in the FP of 21-day-old chickens that had been vaccinated with CVI988 vaccine (healthy), vaccinated and challenged with a very virulent plus (vv+) MDV strain 648A (well protected), or were unvaccinated and challenged with 648A strain (not protected) when compared to uninfected naïve chickens. Oncogenic MDV DNA load, histopathological and immunohistochemical evaluation of the lesions, and immunophenotypic characterization of the infiltrates by flow cytometry were examined. Our results demonstrate that 648A-infected unvaccinated chickens had a significant increase in the percentage of CD3+ T cells, mainly CD4+MHC-II+ cells and CD8+MHC-II+ cells, when compared to all other groups. They also had a significantly decreased number of CD8β+ T cells compared to all other groups. Infection with 648A reduced the percentage of macrophages, not only in the unvaccinated group but also in the CVI988/648A group. In addition, groups that were vaccinated with CVI988, regardless of the challenge status, had higher levels of CD8β+ T cells, suggesting that the vaccine has an enhancing effect on the CTL cells. Our results showed that the load of oncogenic MDV is highly correlated with the infiltration of CD4+MHC-II+ cells and provide further confirmation that FP is indeed an appropriate sample for the early diagnosis of MD.

  PublisherDOI

• Recombinant Lactococcus lactis-based oral vaccine expressing non-toxic alpha toxin domains of Clostridium septicum can offer protection against Clostridial dermatitis in turkeys

  Vaccine · 2025-10-01

  articleOpen accessSenior authorCorresponding

  Clostridial dermatitis (CD), caused by the anaerobic spore-forming Clostridium septicum bacteria, is an important emerging disease of turkeys. Despite its economic burden on the poultry industry, there are no efficacious vaccines currently available for CD control in turkeys. We recently identified two non-toxic domains of C. septicum alpha toxin (ntATX), namely ntATX-D1 and ntATX-D2, and showed that subcutaneous immunization of turkeys with purified recombinant subunit ntATX proteins can offer protection against CD. In the present study, we used the pNZ8124-NICE vector®-based Lactococcus lactis (Str. NZ9000) cloning system to express ntATX-D1 and ntATX-D2 proteins, and immunized turkeys orally at 7, 8 and 9 weeks of age followed by a virulent C. septicum challenge at one-week post-last immunization. Results showed that while both ntATX-D1 and ntATX-D2 vectored-L. lactis vaccines could effectively prevent mortality, the ntATX-D2 carrying vaccine conferred significantly stronger protective immunity, as determined by the gross and histopathological evaluations. Additionally, the immunized birds were found to have antigen-specific serum IgY antibodies. Furthermore, the L. lactis-ntATX-D2 vaccinated turkeys had significantly reduced expression of pro-inflammatory cytokine (Interleukin-1β, IL-6 or Interferon-γ) genes in the skin, muscle, spleen and cecal tonsil tissues when compared to unvaccinated and C. septicum-challenged control group. Our findings show that a L. lactis-based oral recombinant vaccine expressing ntATX-D2 of C. septicum alpha-toxin can provide protective immunity against CD in turkeys, and thus providing a novel scope for devising probiotic-based oral vaccines against important Clostridial diseases in poultry.

  PublisherDOI

• Characterization of immune responses and immunopathology in turkeys experimentally infected with clostridial dermatitis-producing strains of Clostridium septicum

  Veterinary Immunology and Immunopathology · 2024-01-24 · 3 citations

  articleSenior authorCorresponding
  PublisherDOI

• Modulation of functional activity of heat-stressed chicken macrophages by poultry-derived probiotic lactobacilli

  Canadian Journal of Animal Science · 2024-03-05 · 6 citations

  articleOpen accessSenior author

  This study investigated the potential role of lactobacilli in mitigating the negative effects of heat stress on the functional activity of chicken macrophages. Macrophage-like MQ-NCSU cells were incubated at 40 and 44 °C in the presence or absence of a single or a mixture of different poultry-derived Lactobacillus spp., including Lactobacillus animalis, L. acidophilus, L. reuteri, and L. crispatus. Macrophage activation was evaluated by measuring nitric oxide (NO) production, phagocytic activity, and the transcription levels of cytokines, chemokine, and Toll-like receptors (TLRs). Macrophages exposed to heat stress exhibited increased production of NO, diminished expression of interleukin (IL)-1β and IL-12p40, and elevated expression of TLR2 and TLR4, whereas no significant alterations in the phagocytic activity of macrophages were observed. Conversely, treatment of macrophages with probiotic lactobacilli counteracted the effects associated with heat stress. This was evidenced by a notable enhancement in macrophage phagocytic activity, NO production and expression of IL-1β, IL-12p40, IL-18, and chemokine CXCL8, coupled with a reduction in TLR2 and TLR4 expression. These findings suggest that probiotic lactobacilli could be given to chickens to mitigate the negative effects of heat stress on their innate immune system. However, further studies are required to validate the observed effects in an in vivo model.

  PublisherDOI

Frequent coauthors

• Shayan Sharif

  University of Guelph

  36 shared

• Khaled Taha-Abdelaziz

  Clemson University

  19 shared

• Carissa Gaghan

  North Carolina State University

  14 shared

• John F. Prescott

  10 shared

• Valeria R. Parreira

  10 shared

• Mohammadali Alizadeh

  University of Guelph

  10 shared

• Javid P. Mohammed

  Duke University

  9 shared

• Jake Astill

  8 shared

Labs

• Kulkarni LaboratoryPI

Education

• Masters (MVSc)

  Indian Veterinary Research Institute

Awards & honors

• The 2024 Bayer-Snoeyenbos New Investigator Award by the Amer…
• 2024-2025 NC State ‘Goodnight Early Career Innovator Award’