Center for Food Security and Public Health

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Danofloxacin Treatment Alters the Diversity and Resistome Profile of Gut Microbiota in Calves

2021-09-24 , Beyi, Ashenafi Feyisa , Brito-Goulart, Debora , Hawbecker, Tyler , Slagel, Clare , Ruddell, Brandon , Hassall, Alan , Dewell, Renee , Dewell, Grant , Sahin, Orhan , Veterinary Microbiology and Preventive Medicine , Veterinary Diagnostic and Production Animal Medicine , Center for Food Security and Public Health , National Institute of Antimicrobial Resistance Research and Education

Fluoroquinolones, such as danofloxacin, are used to control bovine respiratory disease complex in beef cattle; however, little is known about their effects on gut microbiota and resistome. The objectives were to evaluate the effect of subcutaneously administered danofloxacin on gut microbiota and resistome, and the composition of Campylobacter in calves. Twenty calves were injected with a single dose of danofloxacin, and ten calves were kept as a control. The effects of danofloxacin on microbiota and the resistome were assessed using 16S rRNA sequencing, quantitative real-time PCR, and metagenomic Hi-C ProxiMeta. Alpha and beta diversities were significantly different (p < 0.05) between pre-and post-treatment samples, and the compositions of several bacterial taxa shifted. The patterns of association between the compositions of Campylobacter and other genera were affected by danofloxacin. Antimicrobial resistance genes (ARGs) conferring resistance to five antibiotics were identified with their respective reservoirs. Following the treatment, some ARGs (e.g., ant9, tet40, tetW) increased in frequencies and host ranges, suggesting initiation of horizontal gene transfer, and new ARGs (aac6, ermF, tetL, tetX) were detected in the post-treatment samples. In conclusion, danofloxacin induced alterations of gut microbiota and selection and enrichment of resistance genes even against antibiotics that are unrelated to danofloxacin.

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Influence of Single Dose Enrofloxacin Injection on Development of Fluoroquinolone Resistance in Campylobacter jejuni in Calves

2022-10-13 , Brito-Goulart, Débora , Wu, Zuowei , Cemal Adiguzel, Mehmet , Wilson, Samantha , Xu, Changyun , Pang, Jinji , Dewell, Renee , Dewell, Grant , Plummer, Paul , Zhang, Qijing , Veterinary Microbiology and Preventive Medicine , Veterinary Diagnostic and Production Animal Medicine , Center for Food Security and Public Health

Fluoroquinolone (FQ) resistance in a major foodborne bacterial pathogen, Campylobacter jejuni, derived from cattle has recently become prevalent and poses a significant public health concern. However, the underlying factors for this increase are not entirely clear. To evaluate the effect of enrofloxacin treatment on FQ-resistance development in C. jejuni, 35 commercial calves were equally divided into five groups (Groups 1–5) and were orally inoculated with FQ-susceptible (FQ-S) C. jejuni. Eight days later, Groups 4 and 5 were challenged with Mannheimia haemolytica via a transtracheal route to induce a respiratory disease; after 8 days, Groups 2, 3, 4, and 5 were injected subcutaneously with enrofloxacin (7.5 mg/kg for Groups 2 and 4, and 12.5 mg/kg for Groups 3 and 5). Colonization levels by FQ-resistant (FQ-R) and FQ-S Campylobacter in rectal feces were determined via differential culture throughout the experiment. Before oral inoculation with C. jejuni, only five calves were naturally colonized by Campylobacter, four of which were also colonized by FQ-R C. jejuni (three in Group 1 and one in Group 3). Soon after the oral inoculation, almost all calves in the groups became stably colonized by FQ-S C. jejuni (~3–6 log10 CFU/g), except that the four calves that were pre-colonized before inoculation remained positive with both FQ-R and FQ-S C. jejuni. Following enrofloxacin administration, C. jejuni colonization declined sharply and rapidly in all treated groups to undetectable levels; however, the vast majority of the animals were recolonized by C. jejuni at comparable levels 72 h after the treatment. Notably, no FQ-R C. jejuni was detected in any of the calves that received enrofloxacin, regardless of the drug dose used or disease status of the animals. The lack of detection of FQ-R C. jejuni was likely due to the localized high concentration of the antibiotic in the intestine, which may have prevented the emergence of the FQ-R mutant. These findings indicate that single-dose enrofloxacin use in cattle poses a low risk for selection of de novo FQ-R mutants in C. jejuni.

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Enfermedad de la cola blanca (en P. vannamei)

2015-02-01 , Cuéllar-Anjel, Jorge , Center for Food Security and Public Health

La enfermedad de la cola blanca es una enfermedad viral producida por el Nodavirus del Penaeus vannamei (Penaeus vannamei Nodavirus - PvNV). Esta enfermedad produce mortalidades variables en juveniles y sub-adultos, desarrollándose como una enfermedad progresiva de curso lento. Se desconoce el efecto de la enfermedad en estadíos larvales y en reproductores (camarones adultos). No se han asociado hasta la fecha, episodios de mortalidad súbita o de grandes pérdidas en fincas camaroneras afectadas por el virus

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Measuring CMI responses using the PrimeFlow RNA assay: A new method of evaluating BVDV vaccination response in cattle

2020-03-01 , Falkenberg, Shollie , Dassanayake, Rohana , Neill, John , Roth, James , Walz, Paul , Casas, Eduardo , Ridpath, Julia , Roth, James , Center for Food Security and Public Health , Veterinary Microbiology and Preventive Medicine

Current methods for evaluating bovine viral diarrhea virus (BVDV) vaccination response typically rely on measurement of humoral responses as determined by virus neutralizing antibody titers (VNT) against BVDV. While VNT are correlated with increased protection, research has also shown that cell mediated immunity (CMI) is an important component of a protective response against BVDV. For example, improved protection against BVDV by modified-live viral (MLV) vaccines as compared to killed vaccines is thought to be due to better CMI induced by the MLV. The goal of this work was to evaluate the cell mediated response in vaccinated calves using a novel PrimeFlow RNA assay that incorporates cell surface marker staining with intracellular RNA expression of cytokines and viral RNA detection. Results from this study evaluating mRNA for IFN-γ and IL-2 at 24 h post-BVDV stimulation are similar to previous studies in which IFN-γ was detected in the CD4+ and CD8+ T cell population. However, a novel observation was the detection of IFN-γ mRNA in the NK cell population in vaccinated animals. The NK cell population contributed a significant portion of the IFN-γ produced. This study also demonstrated a decrease in the frequency and amount of BVDV in PBMCs, harvested from vaccinated calves and exposed to BVDV in vitro. Collectively data from this study highlights the association between an increase in IFN-γ and a decreased infection rate of isolated PBMC’s, based on the frequency and amount of BVDV positive cells following in vitro exposure. This new method combines not only the ability to evaluate cellular responses, but also the ability to understand potential antiviral properties associated with cellular responses. This is the first assay to describe and simultaneously measure CMI responses and intracellular viral RNA quantity as a method to evaluate protective responses associated with vaccination.

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Enrofloxacin Alters Fecal Microbiota and Resistome Irrespective of Its Dose in Calves

2021-10-17 , Beyi, Ashenafi Feyisa , Brito-Goulart, Debra , Hawbecker, Tyler , Ruddell, Brandon , Hassall, Alan , Dewell, Renee , Sahin, Orhan , Veterinary Microbiology and Preventive Medicine , Veterinary Diagnostic and Production Animal Medicine , Center for Food Security and Public Health , National Institute of Antimicrobial Resistance Research and Education

Enrofloxacin is a fluoroquinolone drug used to prevent and control bovine respiratory disease (BRD) complex in multiple or single doses, ranging from 7.5 to 12.5 mg/kg body weight. Here, we examined the effects of high and low doses of a single subcutaneously injected enrofloxacin on gut microbiota and resistome in calves. Thirty-five calves sourced for this study were divided into five groups: control (n = 7), two low dose groups (n = 14, 7.5 mg/kg), and two high dose groups (n = 14, 12.5 mg/kg). One group in the low and high dose groups was challenged with Mannheimia haemolytica to induce BRD. Both alpha and beta diversities were significantly different between pre- and post-treatment microbial communities (q < 0.05). The high dose caused a shift in a larger number of genera than the low dose. Using metagenomic ProxiMeta Hi-C, 32 unique antimicrobial resistance genes (ARGs) conferring resistance to six antibiotic classes were detected with their reservoirs, and the high dose favored clonal expansion of ARG-carrying bacterial hosts. In conclusion, enrofloxacin treatment can alter fecal microbiota and resistome irrespective of its dose. Hi-C sequencing provides significant benefits for unlocking new insights into the ARG ecology of complex samples; however, limitations in sample size and sequencing depth suggest that further work is required to validate the findings.

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Enfermedad de las manchas blancas

2013-08-01 , Cuéllar-Anjel, Jorge , Center for Food Security and Public Health

Es una enfermedad producida por el virus del síndrome de las manchas blancas (white spot syndrome virus - WSSV), y produce alta mortalidad en postlarvas y camarones juveniles (puede ser cercana al 100% en pocos días); es de curso agudo y se transmite de forma horizontal o vertical (zooplancton, agua contaminada, sedimentos del fondo de los estanques, canibalismo y predación). Las manifestaciones de la enfermedad suelen aparecer durante los primeros 30-50 días de cultivo en los estanques de producción.

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Enfermedad de la cabeza amarilla

2013-08-01 , Cuéllar-Anjel, Jorge , Center for Food Security and Public Health

La Enfermedad de la Cabeza Amarilla (YHD) es una alteración sistémica de origen viral, cuyas lesiones involucran la mayoría de los órganos vitales del camarón.

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Effect of Danofloxacin Treatment on the Development of Fluoroquinolone Resistance in Campylobacter jejuni in Calves

2022-04-15 , Brito-Goulart, Débora , Wu, Zuowei , Adiguzel, Mehmet Cemal , Schroeder, Anastasia , Singh, Kritika , Xu, Changyun , Ocal, Melda Meral , Dewell, Renee , Dewell, Grant , Plummer, Paul , Zhang, Qijing , Veterinary Diagnostic and Production Animal Medicine , Veterinary Microbiology and Preventive Medicine , Center for Food Security and Public Health

Campylobacter is a leading cause of foodborne gastroenteritis. Recent studies have indicated a rise in fluoroquinolone-resistant (FQ-R) Campylobacter in cattle, where FQ is used to control bovine respiratory disease (BRD). To assess the effect of danofloxacin treatment on the development of FQ-resistance in C. jejuni, 30 commercial calves were divided into Group 1, Group 2, and Group 3 (n = 10), and were all inoculated orally with FQ-susceptible (FQ-S) C. jejuni; seven days later, Group 3 was challenged with transtracheal Mannheimia haemolytica, and one week later, Group 2 and Group 3 were injected subcutaneously with danofloxacin. Rectal feces were collected to determine relative percentages of FQ-R Campylobacter via culture. Before oral inoculation with C. jejuni, 87% of calves were naturally colonized by FQ-R C. jejuni. Two days after the inoculation, FQ-R C. jejuni decreased substantially in the majority of calves. Within 24 h of danofloxacin injection, almost all C. jejuni populations shifted to an FQ-R phenotype in both FQ-treated groups, which was only transitory, as FQ-S strains became predominant during later periods. Genotyping indicated that the spike seen in FQ-R C. jejuni populations following the injection was due mainly to enrichment of preexisting FQ-R C. jejuni, rather than development of de novo FQ resistance in susceptible strains. These results provide important insights into the dynamic changes of FQ-resistant Campylobacter in cattle in response to FQ treatment.

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Enfermedades tóxicas y carenciales en camarones marinos

2015-02-01 , Cuéllar-Anjel, Jorge , Center for Food Security and Public Health

Consiste un fenómeno natural, caracterizado por un aumento en la concentración de ciertas microalgas que forman parte del fitoplancton marino. Cuando se dan ciertas condiciones en el océano, se produce un aumento súbito de organismos fitoplanctónicos, fenómeno que se conoce como floración algal, florecimiento, "bloom" o explosión de poblaciones de microalgas, causando notables cambios en el color de la superficie del agua del mar, debido a la presencia de pigmentos en estos organismos. Dichos pigmentos pueden ser de color rojo, amarillo, verde o café; así mismo, pueden estar combinados dentro de la célula de la microalga, siendo la más frecuente la que produce una coloración rojiz

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Changes in circulating lymphocytes and lymphoid tissue associated with vaccination of colostrum deprived calves

2020-09-26 , Falkenberg, Shollie , Dassanayake, Rohana , Palmer, Mitchell , Roth, James , Silveira, Simone , Roth, James , Gauger, Eric , Kaiser, Troy , Guidarini, Christian , Neill, John , Ridpath, Julia , Center for Food Security and Public Health , Veterinary Microbiology and Preventive Medicine

The objective of this study was to compare immunological responses and lymphoid depletion in young, colostrum deprived calves following administration of vaccines containing modified-live bovine viral diarrhea virus (BVDV). A group of calves exposed to a typical virulence non-cytopathic (ncp) BVDV-2 field strain (ncp exposed) was included to compare responses of calves receiving vaccine to responses generated against a field strain (mimicking a natural infection). A negative control group administered a placebo was used in all comparisons. All vaccines used in the study were administered per manufacturer recommendations while ncp BVDV exposed calves received 5 ml intranasally (2.5 ml/nare; 4.2 × 106 TCID50/ml) of the BVDV-2 field strain. Samples collected at each time point included nasal swabs for virus detection, blood samples for complete blood counts and detection of viremia, PBMCs for flow cytometric analysis, serum for virus neutralization titers, and thymus tissue at necropsy for evaluation of lymphoid depletion. A measurable neutralizing BVDV titer was observed for all treatment groups excluding the control animals, which remained negative during the study period. Virus shedding was only detected from the ncp vaccinated and ncp exposed calves. A decline from baseline was observed for peripheral lymphocyte and CD4+ cells for the groups receiving the adjuvanted cytopathic (cp) vaccine, the double deleted genetically modified (ddGM) vaccine, the ncp vaccine and ncp exposed calves, but not for the control group or groups receiving cp vaccines. Thymus depletion was observed for the ncp vaccine and ncp exposed calves and to a lesser extent for the ddGM vaccine calves. Collectively, these data suggest that the virus biotype, method of attenuation, presentation, and use of adjuvant will influence vaccine impacts on lymphoid tissues and the immune response. As such, multiple variables should be considered when determining costs and benefits of vaccination.