@article{glaize_hull_raymond_vliet_gutierrez-rodriguez_thakur_2022, title={Tracking the Transmission of Antimicrobial-Resistant Non-O157 Escherichia coli and Salmonella Isolates at the Interface of Food Animals and Fresh Produce from Agriculture Operations Using Whole-Genome Sequencing}, volume={8}, ISSN={["1556-7125"]}, DOI={10.1089/fpd.2022.0016}, abstractNote={An increasing number of outbreaks are caused by foodborne pathogens such as Escherichia coli and Salmonella, which often harbor antimicrobial resistance (AMR) genes. We previously demonstrated the transmission of pathogens from animal operations to produce fields on sustainable farms, which illustrated an urgent need to develop and implement novel prevention methods and remediation practices such as the vegetative buffer zone (VBZ) to prevent this movement. The focus of this study was to use whole-genome sequencing (WGS) to characterize the AMR, virulence, and single-nucleotide polymorphism profile of 15 Salmonella and 128 E. coli isolates collected from small-scale dairy and poultry farms on a research station in North Carolina. Phenotypically, seven E. coli and three Salmonella isolates displayed resistance to antibiotics such as tetracycline (n = 4), ampicillin (n = 4), nalidixic acid (n = 3), chloramphenicol (n = 2), sulfisoxazole (n = 1), and streptomycin (n = 1). A single E. coli isolate was found to be resistant to five different antibiotic class types and possessed the blaTEM-150 resistance gene. Virulence genes that facilitate toxin production and cell invasion were identified. Mauve analysis of the E. coli isolates identified seven clusters (dairy-six and poultry-one) indicating that transmission is occurring from animal operations to fresh produce fields and the surrounding environment when the VBZ is denudated. This suggests that the VBZ is a useful barrier to reducing the transmission of enteric pathogens in agricultural systems. Our study demonstrates the prevalence of AMR and virulence genes on small-scale sustainable farms and highlights the advantage of using WGS to assess the impact of the VBZ to reduce the transmission of E. coli and Salmonella.}, journal={FOODBORNE PATHOGENS AND DISEASE}, author={Glaize, Ayanna and Hull, Dawn and Raymond, Luke and Vliet, Arnoud H. M. and Gutierrez-Rodriguez, Eduardo and Thakur, Siddhartha}, year={2022}, month={Aug} }
 @article{glaize_young_harden_gutierrez-rodriguez_thakur_2021, title={The effect of vegetation barriers at reducing the transmission of Salmonella and Escherichia coli from animal operations to fresh produce}, volume={347}, ISSN={["1879-3460"]}, DOI={10.1016/j.ijfoodmicro.2021.109196}, abstractNote={Due to the recent outbreaks of Salmonella and Escherichia coli in fresh produce in the United States, the transfer of foodborne pathogens between animal feeding operations and fresh produce continues to be a considerable risk. The purpose of this study was to determine if the establishment of a vegetation barrier (VB) on small-scale sustainable farms could prevent the transmission of Salmonella and E. coli to nearby fresh produce fields. A 5-layer VB (31 × 49 m) was constructed between a dairy farm, a poultry farm, and a nearby produce field. Fresh produce (i.e., romaine lettuce and tomato), animal feces, and environmental (i.e., air, soil, and barrier) samples were collected for 15 months from 2018 to 2019. Four replicates of soil and fresh produce samples were taken from three plots located 10 m, 61 m, and 122 m away from the respective animal locations and processed for Salmonella and E. coli. Air and vegetative strip samples were sampled at 15-day intervals. Multiple colonies were processed from each positive sample, and a total of 143 positive Salmonella (n = 15) and E. coli (n = 128) isolates were retrieved from the soil, produce, air, and fecal samples. Interestingly, 18.2% of the Salmonella and E. coli isolates (n = 26) were recovered from fresh produce (n = 9) samples. Surprisingly, Salmonella isolates (n = 9) were only found in fecal (n = 3) samples collected from the dairy pasture. Data analysis suggests that the VB is an effective tool at reducing the transmission of E. coli and Salmonella from animal farms to fresh produce fields. However, based on phenotypic and genotypic testing, it is clear that fecal samples from animal farms are not the only source of pathogen contamination. This indicates that the environment (e.g., soil and wind), as well as the initial setup of the farm (e.g., proximity to service roads and produce plot placement), can contribute to the contamination of fresh produce. Our study recommends the need for more effective bioremediation and prevention control measures to use in conjunction with VBs to reduce pathogen transmission.}, journal={INTERNATIONAL JOURNAL OF FOOD MICROBIOLOGY}, author={Glaize, Ayanna and Young, Morgan and Harden, Lyndy and Gutierrez-Rodriguez, Eduardo and Thakur, Siddhartha}, year={2021}, month={Jun} }
 @article{glaize_gutierrez-rodriguez_hanning_díaz-sánchez_gunter_van vliet_watson_thakur_2020, title={Transmission of antimicrobial resistant non-O157 Escherichia coli at the interface of animal-fresh produce in sustainable farming environments}, volume={319}, ISSN={0168-1605}, url={http://dx.doi.org/10.1016/j.ijfoodmicro.2019.108472}, DOI={10.1016/j.ijfoodmicro.2019.108472}, abstractNote={The interaction of typical host adapted enteric bacterial pathogens with fresh produce grown in fields is complex. These interactions can be more pronounced in co-managed or sustainable farms where animal operations are, by design, close to fresh produce, and growers frequently move between the two production environments. The primary objectives of this study were to 1) determine the transmission of STEC or enteric pathogens from small and large animal herds or operations to fresh produce on sustainable farms in TN and NC, 2) identify the possible sources that impact transmission of AMR E. coli, specifically STEC on these systems, and 3) WGS to characterize recovered E. coli from these sources. Samples were collected from raw and composted manure, environment, and produce sources. The serotype, virulence, and genotypic resistance profile were determined using the assembled genome sequences sequenced by Illumina technology. Broth microdilution was used to determine the antimicrobial susceptibility of each isolate against a panel of fourteen antimicrobials. The prevalence of E. coli increased during the summer season for all sources tested. ParSNP trees generated demonstrated that the transmission of AMR E. coli is occurring between animal feeding operations and fresh produce. Ten isolates were identified as serotype O45, a serotype that is associated with the "Big Six" group that is frequently linked with foodborne outbreaks caused by non-O157 E. coli. However, these isolates did not possess the stx gene. The highest frequency of resistance was detected against streptomycin (n = 225), ampicillin (n = 190) and sulfisoxazole FIS (n = 140). A total of 35 (13.7%) isolates from two TN farms were positive for the blaCMY (n = 5) and blaTEM (n = 32) genes. The results of this study show the potential of AMR E. coli transmission between animal feeding operations and fresh produce, and more studies are recommended to study this interaction and prevent dissemination in sustainable farming systems.}, journal={International Journal of Food Microbiology}, publisher={Elsevier BV}, author={Glaize, Ayanna and Gutierrez-Rodriguez, Eduardo and Hanning, Irene and Díaz-Sánchez, Sandra and Gunter, Chris and van Vliet, Arnoud H.M. and Watson, Wes and Thakur, Siddhartha}, year={2020}, month={Apr}, pages={108472} }
 @article{gimeno_glaize_cortes_2018, title={Effect of Marek’s disease vaccines on interferon and toll like receptors when administered in ovo}, volume={201}, ISSN={0165-2427}, url={http://dx.doi.org/10.1016/j.vetimm.2018.05.012}, DOI={10.1016/j.vetimm.2018.05.012}, abstractNote={The effect of two Marek’s disease (MD) vaccines on the chicken embryo immune responses were evaluated. Transcription of interferon (IFN-α, IFN-β, IFN-λ, and IFN-γ) and interferon-I receptors (IFN-AR1 and IFN-AR2), as well as transcription of toll like receptors (TLR-3, TLR-7, and TLR-21) were evaluated in the bursa, thymus, spleen and lung of 1-day-old chickens that had been vaccinated with HVT, CVI988, or sham inoculated at embryonic day 18 (ED18). Each vaccine had a unique effect on the transcription of the evaluated genes and it differs among tissues. HVT increased IFN-γ and TLR-3 transcripts in the spleen and lung and IFN-β in the bursa. The immune responses elicited by CVI988 differed from that observed in the HVT inoculated group. CVI988 downregulated several of the studied genes and only upregulated IFN-β and TLR-21 in spleen. Differences in vaccine replication (53% of spleens and lungs of HVT-vaccinated embryos but only 22% of spleens of CVI988-vaccinated embryos had detectable viral gB transcripts) were detected. Previously, we have shown that intra-amniotic vaccination at ED18 with HVT but not with CVI988 rendered chickens more immunocompetent at hatch. The role of increased transcription of TLR-3 and IFN-γ in such positive effect warrant further investigations.}, journal={Veterinary Immunology and Immunopathology}, publisher={Elsevier BV}, author={Gimeno, Isabel M. and Glaize, Ayanna and Cortes, Aneg L.}, year={2018}, month={Jul}, pages={62–66} }