Clinical presentations and antimicrobial susceptibilities of Corynebacterium cystitidis associated with renal disease in four beef cattle

Background Renal disease caused by Corynebacterium cystitidis in beef cattle may be misclassified as Corynebacterium renale, and limited information about C. cystitidis infections in beef cattle currently is available. Objective To describe clinical presentation, diagnosis, minimum inhibitory concentrations (MICs), and outcome of renal disease caused by C. cystitidis in beef cattle. Methods Retrospective case series. Animals Four client-owned beef cattle. Results All affected cattle had anorexia as a primary complaint. Of the 3 that had ante-mortem diagnostic tests performed, all had pyelonephritis based on azotemia in combination with urinalysis and ultrasonographic findings. Cultures yielded C. cystitidis which was identified by biochemical testing, 16S RNA sequencing, and mass spectrometry. All affected cattle deteriorated despite aggressive treatment, indicating that C. cystitidis infections in beef cattle may carry a poor prognosis. Bacterial isolates collected from the 4 cattle showed similarities in MICs for ampicillin, florfenicol, gentamicin, neomycin, sulfadimethoxine, trimethoprim sulfonamide, and tylosin. Conclusions and clinical importance Corynebacterium cystitidis should be considered in the differential diagnosis of cattle with renal disease. Definitive diagnosis of C. cystitidis as compared to C. renale may be challenging

Assessing the Effects of Medium Chain Fatty Acids and Fat Sources on Porcine Epidemic Diarrhea Virus Viral RNA Stability and Infectivity

Research has confirmed that chemical treatments, such as medium chain fatty acids (MCFA) and commercial formaldehyde, can be effective to reduce the risk of porcine epidemic diarrhea virus (PEDV) cross-contamination in feed. However, the efficacy of individual MCFA levels are unknown. The objective of this study is to compare the efficacy of commercially-available sources of MCFA and other fat sources versus a synthetic custom blend of MCFA to minimize the risk of PEDV cross-contamination as measured by qRT-PCR and bioassay. Treatments were arranged in a 17 × 4 plus 1 factorial with 17 chemical treatments: 1) Positive control with PEDV and no chemical treatment, 2) 0.3% Sal CURB, 3) 1% medium chain fatty acid blend [caproic, caprylic, and capric acids; 1:1:1] (aerosolized), 4) 1% medium chain fatty acid blend [caproic, caprylic, and capric acids; 1:1:1] (non-aerosolized), 5) 0.66% caproic acid, 6) 0.66% caprylic acid, 7) 0.66% capric acid, 8) 0.66% lauric acid, 9) 1% capric and lauric acid mixture (1:1 ratio), 10) FRA C12, 11) 1% choice white grease, 12) 1% soy oil, 13) 1% canola oil, 14) 2% palm kernel oil, 15) 1% palm kernel oil, 16) 2% coconut oil, and 17) 1% coconut oil; 4 analysis days of 0, 1, 3, and 7 post inoculation; and 1 treatment of PEDV negative, untreated feed. Matrices were first chemically treated, then inoculated with PEDV, and stored at room temperature until being analyzed by qRT-PCR. The analyzed values represent threshold cycle (CT), at which a higher CT value represents less detectable RNA. All main effects and interactions were significant (P \u3c 0.002). The interaction of treatment × day indicated that over time the MCFA treatments, either as a mixture or as individual fatty acids, and Sal CURB had the greatest effect of reducing detectable PEDV RNA, which follows the same trend as the main effect of treatment and the bioassay results. Feed treated with individual synthetic MCFA, MCFA mixture, or Sal CURB had fewer (P \u3c 0.05) detectable viral particles than all other treatments. Day also had a significant impact on quantification of viral RNA, and CT increased from 29.5 to 34.6 CT from day 0 to 7, respectively. In summary, time, Sal CURB, 1% MCFA, 0.66% caproic, 0.66% caprylic, and 0.66% capric acids enhance the RNA degradation of PEDV in swine feed. Notably, the MCFA was equally as successful at mitigating PEDV as a commercially-available formaldehyde product in the complete swine diet at 1% inclusion and as individual fatty acids

Evaluation of the Effects of Flushing Feed Manufacturing Equipment with Chemically- Treated Rice Hulls on Porcine Epidemic Diarrhea Virus Cross Contamination During Feed Manufacturing

Various strategies have been proposed to mitigate potential risk of porcine epidemic diarrhea virus (PEDV) transmission via feed and feed ingredients. Wet decontamination has been found to be the most effective decontamination of feed mill surfaces; however, this is not practical on a commercial feed production-scale. Another potential mitigation strategy, easier to implement, would be using chemically-treated rice hulls flushed through the feed manufacturing equipment. The objective of this experiment was to determine the impact of MCFA- or formaldehyde-treated rice hull flush batches as potential PEDV mitigation strategies during feed manufacturing. Feed without evidence of PEDV RNA contamination was inoculated with PEDV. Based on PCR analysis, this feed had a Ct = 30.2 and was confirmed infective in bioassay. After manufacture of PEDV positive feed, untreated rice hulls, or rice hulls treated with Sal CURB, 2%, or 10% medium chain fatty acid blend (MCFA; 1:1:1 ratio of caproic, caprylic, and capric acid) were flushed through laboratory-scale mixers. For the untreated rice hulls, 3 of 6 samples had detectable PEDV RNA (avg. Ct = 41.4) while 1 of 6 Sal CURB treated rice hull flush samples and 2 of 6 of the 2% MCFA rice hull flush samples had detectable PEDV RNA. However, PEDV RNA was not detected in any of the 10% MCFA rice hull flush samples. Additionally, rice hulls treated with 10% MCFA were mixed and discharged through a production-scale mixer and bucket elevator following manufacturing of PEDV positive feed. In the production-scale system, no rice hull flush or feed samples from the mixer following chemically-treated rice hull flush had detectable PEDV RNA. However, one 10% MCFA rice hull sample collected from the bucket elevator discharge spout had detectable PEDV RNA. Dust collected following mixing of PEDV-contaminated feed had a large quantity of PEDV RNA (avg. Ct = 29.4). Dust collected immediately after the 10% MCFA rice hull flush batch had a reduced quantity of PEDV RNA (Ct = 33.7), and the subsequent feed following the 10% rice hull flush had no detectable PEDV RNA. Pigs inoculated with dust collected after manufacturing PEDV-positive feed were shedding PEDV RNA by 2 dpi and continued to have detectable RNA until necropsy. Dust collected from the 10% MCFA rice hull flush batch or the subsequent batch was not infective. Overall, the use of rice hull flushes effectively reduced the quantity of detectable RNA present after mixing a batch of PEDV-positive feed. Chemical treatment of rice hulls with Sal CURB and 10% MCFA provided additional reduction in detectable RNA present in the rice hull flush samples. Finally, dust collected after manufacturing PEDVinoculated feed contains a very high quantity of viral RNA and was found infective, demonstrating it has the potential to serve as a vector for PEDV transmission

Evaluating the Inclusion Level of Medium Chain Fatty Acids to Reduce the Risk of Porcine Epidemic Diarrhea Virus in Complete Feed and Spray-Dried Animal Plasma

Research has confirmed that chemical treatments, such as medium chain fatty acids (MCFA) and commercial formaldehyde, can be effective to reduce the risk of porcine epidemic diarrhea virus (PEDV) cross-contamination in feed. However, the efficacy of MCFA levels below 2% inclusion is unknown. The objective of this experiment was to evaluate if a 1% inclusion of MCFA is as effective at PEDV mitigation as a 2% inclusion or formaldehyde in swine feed and spray-dried animal plasma (SDAP). Treatments were arranged in a 4 × 2 × 7 plus 2 factorial with 4 chemical treatments: 1) PEDV positive with no chemical treatment, 2) 0.325% commercial formaldehyde, 3) 1% MCFA, and 4) 2% MCFA. The 2 matrices were: 1) complete swine diet and 2) SDAP; with 7 analysis days: 0, 1, 3, 7, 14, 21, and 42 post inoculation; and 1 treatment each of PEDV negative untreated feed and plasma. Matrices were first chemically treated, then inoculated with PEDV, and stored at room temperature until being analyzed by RTqPCR. The analyzed values represent threshold cycle (CT), at which a higher CT value represents less detectable RNA. All main effects and interactions were significant (P \u3c 0.009). Feed treated with MCFA, regardless of inclusion level, had fewer (P \u3c 0.05) detectable viral particles than feed treated with formaldehyde. However, the SDAPtreated with either 1% or 2% MCFA had similar (P \u3e 0.05) concentrations of detectable PEDV RNA as the untreated SDAP, while the SDAP treated with formaldehyde had fewer detectable viral particles (P \u3c 0.05). The complete feed had a lower (P \u3c 0.05) quantity of PEDV RNA than SDAP (39.5 vs. 35.0 for feed vs. SDAP, respectively) (P \u3c 0.05). Analysis day also decreased (P \u3c 0.05) the quantity of detectable viral particles from d 0 to 42, (33.2 vs. 44.0, respectively). In summary, time, formaldehyde, and MCFA all appear to enhance RNA degradation of PEDV in swine feed and ingredients; however, their effectiveness varies within matrix. The 1% inclusion level of MCFA was as effective as 2% in complete feed, but neither were effective at reducing the magnitude of PEDV RNA in SDAP

Clinical presentations and antimicrobial susceptibilities of Corynebacterium cystitidis associated with renal disease in four beef cattle

Background Renal disease caused by Corynebacterium cystitidis in beef cattle may be misclassified as Corynebacterium renale, and limited information about C. cystitidis infections in beef cattle currently is available. Objective To describe clinical presentation, diagnosis, minimum inhibitory concentrations (MICs), and outcome of renal disease caused by C. cystitidis in beef cattle. Methods Retrospective case series. Animals Four client-owned beef cattle. Results All affected cattle had anorexia as a primary complaint. Of the 3 that had ante-mortem diagnostic tests performed, all had pyelonephritis based on azotemia in combination with urinalysis and ultrasonographic findings. Cultures yielded C. cystitidis which was identified by biochemical testing, 16S RNA sequencing, and mass spectrometry. All affected cattle deteriorated despite aggressive treatment, indicating that C. cystitidis infections in beef cattle may carry a poor prognosis. Bacterial isolates collected from the 4 cattle showed similarities in MICs for ampicillin, florfenicol, gentamicin, neomycin, sulfadimethoxine, trimethoprim sulfonamide, and tylosin. Conclusions and clinical importance Corynebacterium cystitidis should be considered in the differential diagnosis of cattle with renal disease. Definitive diagnosis of C. cystitidis as compared to C. renale may be challenging.This is the published version of the following article: Smith, Joe S., Adam C. Krull, Jennifer A. Schleining, Rachel J. Derscheid, and Amanda J. Kreuder. "Clinical presentations and antimicrobial susceptibilities of Corynebacterium cystitidis associated with renal disease in four beef cattle." Journal of Veterinary Internal Medicine 34, no. 5 (2020): 2169-2174. DOI: 10.1111/jvim.15844. Copyright 2020 The Authors. Attribution-NonCommercial 4.0 International (CC BY-NC 4.0). Posted with permission

Cough associated with the detection of Mycoplasma hyopneumoniae DNA in clinical and environmental specimens under controlled conditions

Background: The association of cough with Mycoplasma hyopneumoniae (MHP) DNA detection in specimens was evaluated under conditions in which the MHP status of inoculated and contact-infected pen mates was closely monitored for 59 days post-inoculation (DPI). Methods: Seven-week-old pigs (n = 39) were allocated to five rooms (with one pen). Rooms contained 9 pigs each, with 1, 3, 6, or 9 MHP-inoculated pigs, respectively, except Room 5 (three sham-inoculated pigs). Cough data (2 × week) and specimens, tracheal swabs (2 × week), oral fluids (daily), drinker wipes (~ 1 × week), and air samples (3 × week) were collected. At 59 DPI, pigs were euthanized, and lung and trachea were evaluated for gross and microscopic lesions. Predictive cough value to MHP DNA detection in drinker and oral fluid samples were estimated using mixed logistic regression. Results: Following inoculation, MHP DNA was first detected in tracheal swabs from inoculated pigs (DPI 3), then oral fluids (DPI 8), air samples (DPI 10), and drinker wipes (21 DPI). MHP DNA was detected in oral fluids in 17 of 59 (Room 1) to 43 of 59 (Room 3) samples, drinker wipes in 4 of 8 (Rooms 2 and 3) to 5 of 8 (Rooms 1 and 4) samples, and air samples in 5 of 26 (Room 2) or 3 of 26 (Room 4) samples. Logistic regression showed that the frequency of coughing pigs in a pen was associated with the probability of MHP DNA detection in oral fluids (P < 0.01) and nearly associated with drinker wipes (P = 0.08). Pathology data revealed an association between the period when infection was first detected and the severity of gross lung lesions. Conclusions: Dry, non-productive coughs suggest the presence of MHP, but laboratory testing and MHP DNA detection is required for confirmation. Based on the data from this study, oral fluids and drinker wipes may provide a convenient alternative for MHP DNA detection at the pen level when cough is present. This information may help practitioners in specimen selection for MHP surveillance.This article is published as Silva, Ana Paula S. Poeta, Gabriel Y. Storino, Franco S. Matias Ferreyra, Min Zhang, Eduardo Fano, Dale Polson, Chong Wang et al. "Cough associated with the detection of Mycoplasma hyopneumoniae DNA in clinical and environmental specimens under controlled conditions." Porcine Health Management 8, no. 1 (2022): 1-13. DOI: 10.1186/s40813-022-00249-y. Copyright 2022 The Author(s). Attribution 4.0 International (CC BY 4.0). Posted with permission

Clinical presentations and antimicrobial susceptibilities of Corynebacterium cystitidis

Background Renal disease caused by Corynebacterium cystitidis in beef cattle may be misclassified as Corynebacterium renale, and limited information about C. cystitidis infections in beef cattle currently is available. Objective To describe clinical presentation, diagnosis, minimum inhibitory concentrations (MICs), and outcome of renal disease caused by C. cystitidis in beef cattle. Methods Retrospective case series. Animals Four client-owned beef cattle. Results All affected cattle had anorexia as a primary complaint. Of the 3 that had ante-mortem diagnostic tests performed, all had pyelonephritis based on azotemia in combination with urinalysis and ultrasonographic findings. Cultures yielded C. cystitidis which was identified by biochemical testing, 16S RNA sequencing, and mass spectrometry. All affected cattle deteriorated despite aggressive treatment, indicating that C. cystitidis infections in beef cattle may carry a poor prognosis. Bacterial isolates collected from the 4 cattle showed similarities in MICs for ampicillin, florfenicol, gentamicin, neomycin, sulfadimethoxine, trimethoprim sulfonamide, and tylosin. Conclusions and clinical importance Corynebacterium cystitidis should be considered in the differential diagnosis of cattle with renal disease. Definitive diagnosis of C. cystitidis as compared to C. renale may be challenging

RSV antigen detected by immunohistochemistry (IHC).

<p>Control bronchioles and alveoli (Control Br and Control Alv) lack RSV antigen while bronchioles and alveoli of FI-RSV-vaccinated lambs had significantly reduced levels of RSV antigen compared to mock-vaccinated (MockVac) lambs. Control(s) n = 4; MockVac Br n = 4; MockVac Alv n = 4; FI-RSV Br n = 4; FI-RSV Alv n = 4. Error bars = SEM, *<i>P</i><0.05, **<i>P</i><0.01, ***<i>P</i><0.001.</p

Serum neutralization titers of FI-RSV-vaccinated lambs (FI-vaccinated) (n = 4) were significantly increased compared to mock-vaccinated lambs (n = 4) (*P<0.05).

<p>Error bars = SEM.</p