Healthy Pigs Research Articles

Post-weaning diarrhea in pigs from a single Danish production herd was not associated with the pre-weaning fecal microbiota composition and diversity.

The association between the porcine pre-weaning gut microbiota composition and diversity, and subsequent post-weaning diarrhea (PWD) susceptibility is currently being studied. In this longitudinal study, we examined the association between pre-weaning fecal microbiome composition and diversity, and PWD development in a Danish sow herd. Forty-five pigs were followed from birth until 7 days after weaning (post-natal day (PND) 33). At PND 33, the pigs were categorized as PWD cases or healthy controls based on fecal consistency. We compared their fecal microbiomes at PND 8, late lactation (PND 27) and 7 days post weaning (PND 33) using 16S rRNA V3 region high-throughput sequencing. At PND 27 and 33, we also weighed the pigs, assessed fecal shedding of hemolytic Escherichia coli by culture and characterized hemolytic isolates by ETEC virulence factors with PCR and by whole genome sequencing. A total of 25 out of 45 pigs developed PWD and one Enterotoxigenic E. coli strain with F18:LT:EAST1 virotype was isolated from most pigs. At PND 33, we found differences in beta diversity between PWD and healthy pigs (R2 = 0.027, p = 0.009) and that body weight was associated with both alpha and beta diversity. Pre-weaning fecal microbiome diversity did not differ between PWD and healthy pigs and we found no significant, differentially abundant bacteria between them. In the production herd under study, pre-weaning fecal microbiome diversity and composition were not useful indicators of PWD susceptibility.

The dose regimen formulation of doxycycline hydrochloride and florfenicol injection based on ex vivo pharmacokinetic-pharmacodynamic modeling against the Actinobacillus pleuropneumoniae in pigs

Doxycycline hydrochloride and florfenicol combination (DoxHcl&FF) is an effective treatment for respiratory diseases. In the study, our objective was to evaluate the activity of DoxHcl&FF against Actinobacillus pleuropneumoniae (APP) in porcine pulmonary epithelial lining fluid (PELF) and the optimal dosage scheme to avoid the development of resistance. The DoxHcl&FF was administered intramuscularly (IM) at 20 mg/kg, and the PELF was collected at different time points. The minimum inhibitory concentration (MIC) and time-mortality curves were also included in the study. Based on the sigmoid Emax equation and dose equations, the study integrated the in vivo pharmacokinetic data of infected pigs and ex vivo pharmacodynamic data to obtain the area under concentration time curve (AUC0-24h)/MIC values in PELF and achieve bacteriostatic activity, bactericidal activity and the virtual eradication of bacteria. The study showed that the combination of DoxHcl and FF caused no significant changes in PK parameters. The peak concentration (Cmax) of FF in healthy and diseased pigs was 8.87 ± 0.08 μg/mL and 8.67 ± 0.07 μg/mL, the AUC0-24h were 172.75 ± 2.52 h·μg/mL and 180.22 ± 3.13 h·μg/mL, the Cmax of DoxHcl was 7.91 ± 0.09 μg/mL and 7.99 ± 0.05 μg/mL, and the AUC0-24h was 129.96 ± 3.70 h·μg/mL and 169.82 ± 4.38 h·μg/mL. DoxHcl&FF showed strong concentration-dependent tendencies. The bacteriostatic, bactericidal, and elimination activity were calculated as 5.61, 18.83 and 32.68 h, and the doses were 1.37 (bacteriostatic), 4.59 (bactericidal) and 7.99 (elimination) mg/kg. These findings indicated that the calculated recommended dose could assist in achieving more precise administration, increasing the effectiveness of DoxHcl&FF treatment for APP infections.

Assessment of glomerular filtration and tubular secretion in baboons with life-supporting pig kidney grafts.

With pig kidney xenotransplantation nearing clinical reality, it is imperative to measure pig kidney function in the graft recipients. Our aims were (i) to compare inulin clearance after a short intravenous (IV) bolus with steady-state inulin IV infusion, (ii) to use this method to measure the glomerular filtration rate (GFR), and (iii) to determine the tubular secretory function using cefoxitin in a pig-to-baboon renal transplant model. A short IV infusion of inulin and cefoxitin were followed by a maintenance IV infusion of inulin over 5 h in seven healthy baboons, three healthy pigs, and five baboons after bilateral native nephrectomy and intra-abdominal pig renal transplantation. Blood and urine samples were collected. Serum and urinary inulin and serum cefoxitin concentrations measured by validated assays were used to calculate GFR and renal secretion. GFR calculatedwere similar by both methods. The body weight normalized total body clearance of inulin was similar in pigs and baboons despite differences in absolute clearances. Pig kidney transplanted into baboons provided similar clearance in baboons when normalized to baboon body weight and sustained filtration and secretory functions. The study documented that pig kidneys support the physiologic needs of baboons and are likely to support human recipients as well.

Highly conserved composite transposon harbouring aerobactin iuc3 in Klebsiella pneumoniae from pigs.

Klebsiella pneumoniae is an important opportunistic pathogen associated with severe invasive disease in humans. Hypervirulent K. pneumoniae, which are K. pneumoniae with several acquired virulence determinants such as the siderophore aerobactin and others, are more prominent in countries in South and South-East Asia compared to European countries. This Klebsiella pathotype is capable of causing liver abscesses in immunocompetent persons in the community. K. pneumoniae has not been extensively studied in non-human niches. In the present study, K. pneumoniae isolated from caecal samples (n=299) from healthy fattening pigs in Norway were characterized with regard to population structure and virulence determinants. These data were compared to data from a previous study on K. pneumoniae from healthy pigs in Thailand. Lastly, an in-depth plasmid study on K. pneumoniae with aerobactin was performed. Culturing and whole-genome sequencing was applied to detect, confirm and characterize K. pneumoniae isolates. Phylogenetic analysis described the evolutionary relationship and diversity of the isolates, while virulence determinants and sequence types were detected with Kleborate. Long-read sequencing was applied to obtain the complete sequence of virulence plasmids harbouring aerobactin. A total of 48.8 % of the investigated Norwegian pig caecal samples (n=299) were positive for K. pneumoniae. Acquired virulence determinants were detected in 72.6 % of the isolates, the most prominent being aerobactin (69.2 %), all of which were iuc3. In contrast, only 4.6 % of the isolates from Thailand harboured aerobactin. The aerobactin operon was located on potentially conjugative IncFIBK/FIIK plasmids of varying sizes in isolates from both countries. A putative, highly conserved composite transposon with a mean length of 16.2 kb flanked by truncated IS3-family IS407-group insertion sequences was detected on these plasmids, harbouring the aerobactin operon as well as several genes that may confer increased fitness in mammalian hosts. This putative composite transposon was also detected in plasmids harboured by K. pneumoniae from several countries and sources, such as human clinical samples. The high occurrence of K. pneumoniae harbouring aerobactin in Norwegian pigs, taken together with international data, suggest that pigs are a reservoir for K. pneumoniae with iuc3. Truncation of the flanking ISKpn78-element suggest that the putative composite transposon has been permanently integrated into the plasmid, and that it is no longer mobilizable.

Transcriptome Profile Reveals Differences between Remote and Ischemic Myocardium after Acute Myocardial Infarction in a Swine Model.

Acute myocardial infarction (AMI) is the consequence of an acute interruption of myocardial blood flow delimiting an area with ischemic necrosis. The loss of cardiomyocytes initiates cardiac remodeling in the myocardium, leading to molecular changes in an attempt to recover myocardial function. The purpose of this study was to unravel the differences in the molecular profile between ischemic and remote myocardium after AMI in an experimental model. To mimic human myocardial infarction, healthy pigs were subjected to occlusion of the mid-left anterior descending coronary artery, and myocardial tissue was collected from ischemic and remote zones for omics techniques. Comparative transcriptome analysis of both areas was accurately validated by proteomic analysis, resulting in mitochondrion-related biological processes being the most impaired mechanisms in the infarcted area. Moreover, Immune system process-related genes were up-regulated in the remote tissue, mainly due to the increase of neutrophil migration in this area. These results provide valuable information regarding differentially expressed genes and their biological functions between ischemic and remote myocardium after AMI, which could be useful for establishing therapeutic targets for the development of new treatments.

Dietary fiber alters immunity and intestinal barrier function of different breeds of growing pigs.

Dietary fiber (DF) regulates immune response and barrier function by interacting with epithelial cells and immune cells. However, the differences in the regulation of intestinal health of different pig breeds by DF remain obscure. A total of 60 healthy pigs (20 pigs/breed) from Taoyuan black (TB), Xiangcun black (XB), and Duroc (DR) pigs (body weight = 11.00 ± 1.00kg) were fed two different levels (low and high) of DF for 28 days to evaluate the differences in the modulation of intestinal immunity and barrier function by DF in different pig breeds. TB and XB pigs had higher plasma Eos level, Eos%, and Lym% but lower Neu level compared with the DR pigs when fed low DF (LDF). The TB and XB pigs had higher plasma Eos, MCV, and MCH levels and Eos% while lower Neu% compared with the DR pigs when fed high DF (HDF). HDF decreased IgA, IgG, IgM, and sIgA concentrations in the ileum of TB and XB pigs compared with the DR pigs, while the plasma IgG and IgM concentrations of TB pigs were higher than those of the DR pigs. Moreover, compared with the DR pigs, HDF decreased the levels of IL-1β, IL-17, and TGF-β in the plasma, and IL-1β, IL-2, IL-6, IL-10, IL-17, IFN-γ, TGF-β, and TNF-α in the ileum of TB and XB pigs. However, HDF did not affect the mRNA expression of cytokines in the ileum of TB, XB, and DR pigs, while HDF increased the TRAF6 expression of TB pigs compared with the DR pigs. In addition, HDF increased the Claudin abundance of TB and DR pigs compared with the pigs feeding with LDF. Moreover, in the LDF and HDF groups, the XB pigs had higher protein abundances of Claudin and ZO-1 compared with the TB and DR pigs. DF regulated the TB and DR pigs' plasma immune cells, the XB pigs showed enhanced barrier function, and the DR pigs had increased ileal inflammation, which indicates that Chinese indigenous pigs are more DF tolerant than the DR pigs.

Nasal staphylococci community of healthy pigs and pig-farmers in Aragon (Spain). Predominance and within-host resistome diversity in MRSA-CC398 and MSSA-CC9 lineages

This study investigated the diversity and carriage rate of nasal Staphylococcus spp., and within-host variability of antimicrobial resistance (AMR), virulence determinants, immune evasion cluster (IEC) types and genetic lineages of S. aureus isolates. Also, the co-carriage rate of CoNS with S. aureus in the same nasal niche of healthy pigs and pig-farmers were studied in four pig-farms (A-D) in Aragon (Spain). Nasal samples of 40 pigs (10 pigs/farm) and 10 pig-farmers (2–3/farm) were collected for staphylococci recovery and isolates (up to 9 per sample) were identified by MALDI-TOF-MS. The virulence and AMR genes and spa-types of S. aureus isolates were investigated by PCR/sequencing. Of the 243 staphylococci identified (10 different species), 142 were S. aureus and 51 distinct isolates were selected for further characterization (that corresponded to one S. aureus/sample or more than one if they showed different AMR phenotypes). The highest carriage rate in pigs was S. aureus (65%) and S. chromogenes (22.5%), whereas in the pig-farmers, S. aureus (80%) and S. epidermidis (40%). Methicillin-resistant S. aureus (MRSA) were detected in 60% of pigs and 70% of pig-farmers. Only six S. aureus isolates were methicillin-susceptible (MSSA), all from farm-C. A multidrug resistance (MDR) phenotype was detected in all MRSA and in 83.3% of the MSSA isolates. All MRSA isolates were CC398 with spa-type t011 being the predominant (92.7%), while t034, t1451 (only in pig-farmers) and t4571 (in pigs) were also found. MSSA-CC9 isolates (t191, t1430) were detected in farm-C. All S. aureus isolates were negative for luk-S/F-PV, tst, and scn genes, except one MSSA-CC45-t065-IEC-type C isolate from a pig-farmer. About 34.6% and 75.0% of the pigs and pig-farmers S. aureus carriers, respectively, harboured within-host varied spa-types or resistomes. Moreover, 40% of pigs and pig-farmers with MRSA-CC398 had no CoNS nasal co-carriage, and 23.3% had ≥2 CoNS carriage. Conversely, only 16.7% of MSSA carriers had no CoNS co-carriage, whereas 50% had ≥2 CoNS carriages. The very high MRSA level and within-host resistome diversities highlight the need for multiple samplings to account for the dynamics of AMR crisis and control of inter-host transmission of S. aureus in pig-farms using “One Health” approach.

The evaluation of the effect of tafluprost on the intraocular pressure of healthy male guinea pigs under different light-and-darkness regimes.

Ocular hypertension is one of the most underdiagnosed ocular abnormalities among guinea pigs around the world. The current study investigates the effect of 0.0015% preservative-free tafluprost ophthalmic solution (Zioptan) on the intraocular pressure of 16 healthy male guinea pigs (Cavia porcellus) under different light/darkness regimes. All guinea pigs received a single drop of tafluprost at 5:30 in the right eye, whereas the contralateral eyes served as control to receive a placebo. Then, the animals were randomly divided into two groups; group A was exposed to light, whereas group B was placed in darkness from 5:30 to 18:00. Rebound tonometry (TonoVet) was instrumented to measure IOP values at 5:30 (baseline), 6:00, 7:00, 8:00, 9:00 and then every 3h until 18:00. The maximum IOP reduction associated with tafluprost was observed at 6:00 by -1.4±1.1mmHg (p-value=0.026) and -2.5±1.2mmHg (p-value=0.011) in group A and B, respectively (repeated measure ANOVA test). There was a significant difference between the mean right and left eye IOP values in both groups at 5:30, 6:00, 7:00 and 8:00 (p-value <0.05), which was greater in amount in group B compared to group A due to the effect of darkness on IOP reduction. It is suggested that the variations of IOP in different light/dark conditions be taken into consideration when applying ocular hypotensive agents on guinea pigs' eyes.

Individualised flow-controlled versus pressure-controlled ventilation in a porcine oleic acid-induced acute respiratory distress syndrome model.

A continuous gas flow provided by flow-controlled ventilation (FCV) facilitates accurate dynamic compliance measurement and allows the clinician to individually optimise positive end-expiratory and peak pressure settings accordingly. The aim of this study was to compare the efficiency of gas exchange and impact on haemodynamics between individualised FCV and pressure-controlled ventilation (PCV) in a porcine model of oleic acid-induced acute respiratory distress syndrome (ARDS). Randomised controlled interventional trial conducted on 16 pigs. Animal operating facility at the Medical University Innsbruck. ARDS was induced in lung healthy pigs by intravenous infusion of oleic acid until moderate-to-severe ARDS at a stable Horowitz quotient (PaO 2 FiO 2-1 ) of 80 to 120 over a period of 30 min was obtained. Ventilation was then either performed with individualised FCV ( n = 8) established by compliance-guided pressure titration or PCV ( n = 8) with compliance-guided titration of the positive end-expiratory pressure and peak pressure set to achieve a tidal volume of 6 ml kg -1 over a period of 2 h. Gas exchange parameters were assessed by the PaO 2 FiO 2-1 quotient and CO 2 removal by the PaCO 2 value in relation to required respiratory minute volume. Required catecholamine support for haemodynamic stabilisation was measured. The FCV group showed significantly improved oxygenation [149.2 vs. 110.4, median difference (MD) 38.7 (8.0 to 69.5) PaO 2 FiO 2-1 ; P = 0.027] and CO 2 removal [PaCO 2 7.25 vs. 9.05, MD -1.8 (-2.87 to -0.72) kPa; P = 0.006] at a significantly lower respiratory minute volume [8.4 vs. 11.9, MD -3.6 (-5.6 to -1.5) l min -1 ; P = 0.005] compared with PCV. In addition, in FCV-pigs, haemodynamic stabilisation occurred with a significant reduction of required catecholamine support [norepinephrine 0.26 vs. 0.86, MD -0.61 (-1.12 to -0.09) μg kg -1 min -1 ; P = 0.037] during 2 ventilation hours. In this oleic acid-induced porcine ARDS model, individualised FCV significantly improved gas exchange and haemodynamic stability compared with PCV. Protocol no.: BMBWF-66.011/0105-V/3b/2019).

Characterisation of new animal cell cultures’ sensitivity to &lt;i&gt;Coxsackievirus B5&lt;/i&gt; and &lt;i&gt;Herpes simplex virus‑1&lt;/i&gt;

The increase in the number of cell cultures for virology and biotechnology enhances the chances of a successful response to threats related to outbreaks of well-known and new human infectious diseases. It is a vital task to search for cell cultures sensitive to a wide spectrum of viruses.The aim of the study was to investigate the sensitivity of new diploid animal cell cultures (fibroblasts of a foetal pig’s kidneys and larynx) to Coxsackievirus B5 (CVB5) and Herpes simplex virus-1 (HSV-1).Materials and methods. The cultures of porcine foetal kidney fibroblasts (PFKF) and porcine foetal larynx fibroblasts (PFLF) were derived from a foetus of a healthy pig by mild trypsinisation. The study determined the sensitivity of these new PFKF and PFLF cultures to the above-mentioned viruses by the cytopathic effect (CPE) expressed as a percentage. The infectious activity of CVB5 was studied using real-time polymerase chain reaction (PCR) with the determination of amplification cycle threshold values (Ct); that of HSV-1 was studied using quantitative titration of the virus-containing liquid (VCL). Infectious activity values were expressed as tissue culture 50% infective doses (TCID50).Results. The authors developed diploid PFKF and PFLF cell cultures. PFKF cells demonstrated high sensitivity to CVB5, with a CPE of 87.5±3.3% after passage 3 and a satisfactory concentration of enterovirus RNA in the VCL of 22–24 Ct . The sensitivity of PFKF cells to HSV-1 corresponded to a CPE of 92.1±5.5%. In these cells, the infectious activity of HSV-1 corresponded to 104.25 TCID50/0.2 mL. The experiments with PFLF cells showed low CPE and infectious activity values for both viruses.Conclusions. The study demonstrated high CPE values with the CVB5 (CB5-8100) and HSV-1 (HSV-1/L-2) strains as examples and confirmed the sensitivity of the new diploid PFKF cell culture to these test viruses. Thus, the PFKF cell culture offers potential applications in virology and biotechnology and may be a candidate for testing other strains of CVB5 and HSV-1.

Porcine intestinal glycosphingolipids recognized by Brachyspira hyodysenteriae.

Swine dysentery caused by Brachyspira hyodysenteriae is a disease present worldwide with an important economic impact on the farming business, resulting in an increased use of antibiotics. In the present study, we investigated the binding of B. hyodysenteriae to glycosphingolipids from porcine small intestinal epithelium in order to determine the glycosphingolipids involved in B. hyodysenteriae adhesion. Specific interactions between B. hyodysenteriae and two non-acid glycosphingolipids were obtained. These binding-active glycosphingolipids, were characterized by mass spectrometry as lactotetraosylceramide (Galβ3GlcNAcβ3Galβ4Glcβ1Cer) and the B5 glycosphingolipid (Galα3Galβ4GlcNAcβ3Galβ4Glcβ1Cer). Comparative binding studies using structurally related reference glycosphingolipids showed that B. hyodysenteriae binding to lactotetraosylceramide required an unsubstituted terminal Galβ3GlcNAc sequence, while for binding to the B5 pentaosylceramide the terminal Galα3Galβ4GlcNAc sequence is the minimum element recognized by the bacteria. Binding of Griffonia simplicifolia IB4 lectin to pig colon tissue sections from healthy control pig and B. hyodysenteriae infected pigs showed that in the healthy pigs the Galα3Gal epitope was mainly present in the lamina propria. In contrast, in four out of five pigs with swine dysentery there was an increased expression of Galα3Gal in the goblet cells and in the colonic crypts, where B. hyodysenteriae also was present. The one pig that had recovered by the time of necropsy had the Galα3Gal epitope only in the lamina propria. These data are consistent with a model where a transient increase in the carbohydrate sequence recognized by the bacteria occur in colonic mucins during B. hyodysenteriae infection, suggesting that the mucins may act as decoys contributing to clearance of the infection. These findings may lead to novel strategies for treatment of B. hyodysenteriae induced swine dysentery.

Permanent Tooth Eruption Patterns in Nigerian Local Pigs.

Pigs are diphyodonts with heterodont dentition and have been used in studies involving teeth and jawbone regeneration, and dental implants. Patterns of tooth eruption are used to age animals and determine the effects of environmental and genetic influences on occurrence of variations. As with other species, variations exist in the tooth eruption pattern in pigs. The aim of this study was to determine the permanent teeth eruption patterns of Nigerian local pigs. Twenty-six healthy pigs were observed throughout the study period. Pigs were firmly held in dorsal or lateral recumbency and their mouths gently held open to visually examine all quadrants of the dental arches (right and left maxillary, right and left mandibular). Observations were recorded from 16 weeks of age, until the last permanent tooth erupted. Results obtained from the study showed that males had lower mean values for eruption time (54%) of examined teeth in comparison to females. The mean values of eruption time for the maxillary third incisor, the mandibular and maxillary canines, and the mandibular fourth premolar teeth were statistically significant in the males (P = .0017, P = .0088, P = .0002 and P = .0244, respectively). Sixty-nine percent of the adult pigs did not have eruption of the mandibular first premolar, while polydontia was observed in the maxillary and mandibular incisors. These results show that intra-breed and inter-breed variations exist in the dental eruption pattern in pigs. The data obtained from this study can be used for comparative dental studies and can aid further research on the developmental anatomy of Nigerian local pigs.

Characterising spinal cerebrospinal fluid flow in the pig with phase-contrast magnetic resonance imaging

BackgroundDetecting changes in pulsatile cerebrospinal fluid (CSF) flow may assist clinical management decisions, but spinal CSF flow is relatively understudied. Traumatic spinal cord injuries (SCI) often cause spinal cord swelling and subarachnoid space (SAS) obstruction, potentially causing pulsatile CSF flow changes. Pigs are emerging as a favoured large animal SCI model; therefore, the aim of this study was to characterise CSF flow along the healthy pig spine.MethodsPhase-contrast magnetic resonance images (PC-MRI), retrospectively cardiac gated, were acquired for fourteen laterally recumbent, anaesthetised and ventilated, female domestic pigs (22–29 kg). Axial images were obtained at C2/C3, T8/T9, T11/T12 and L1/L2. Dorsal and ventral SAS regions of interest (ROI) were manually segmented. CSF flow and velocity were determined throughout a cardiac cycle. Linear mixed-effects models, with post-hoc comparisons, were used to identify differences in peak systolic/diastolic flow, and maximum velocity (cranial/caudal), across spinal levels and dorsal/ventral SAS. Velocity wave speed from C2/C3 to L1/L2 was calculated.ResultsPC-MRI data were obtained for 11/14 animals. Pulsatile CSF flow was observed at all spinal levels. Peak systolic flow was greater at C2/C3 (dorsal: − 0.32 ± 0.14 mL/s, ventral: − 0.15 ± 0.13 mL/s) than T8/T9 dorsally (− 0.04 ± 0.03 mL/s; p < 0.001), but not different ventrally (− 0.08 ± 0.08 mL/s; p = 0.275), and no difference between thoracolumbar levels (p > 0.05). Peak diastolic flow was greater at C2/C3 (0.29 ± 0.08 mL/s) compared to T8/T9 (0.03 ± 0.03 mL/s, p < 0.001) dorsally, but not different ventrally (p = 1.000). Cranial and caudal maximum velocity at C2/C3 were greater than thoracolumbar levels dorsally (p < 0.001), and T8/T9 and L1/L2 ventrally (p = 0.022). Diastolic velocity wave speed was 1.41 ± 0.39 m/s dorsally and 1.22 ± 0.21 m/s ventrally, and systolic velocity wave speed was 1.02 ± 0.25 m/s dorsally and 0.91 ± 0.22 m/s ventrally.ConclusionsIn anaesthetised and ventilated domestic pigs, spinal CSF has lower pulsatile flow and slower velocity wave propagation, compared to humans. This study provides baseline CSF flow at spinal levels relevant for future SCI research in this animal model.

An investigation of fusion strategies for boosting pig cough sound recognition

The recognition of pig cough sounds is an effective way to monitor pig respiratory diseases which seriously affect healthy pig breeding. Due to the complexity of the pig-housing environment, achieving high precision cough recognition by relying only on a single feature or classifier is challenging. Therefore, in this study we investigated two fusion strategies, namely feature fusion and classifier fusion, to boost classification accuracy. For feature fusion, we improved the previously proposed feature fusion algorithm and selected better acoustic and image features for fusion. We also proposed a novel classifier fusion algorithm. In the algorithm, the support vector machine (SVM) classifiers trained by the acoustic features and deep features were fused by soft voting for pig cough prediction. The sound data collected in the pig barn were used to validate the proposed methods. Our methods achieved a substantial classification rate of 97.47% and 99.20% for feature fusion and classifier fusion, respectively. The results demonstrate that our proposed fusion strategies can significantly improve the recognition accuracy of pig cough sounds.

Epidemiology and Genetic Characteristics of Porcine Reproductive and Respiratory Syndrome Virus in the Hunan and Hebei Provinces of China.

Porcine reproductive and respiratory syndrome virus (PRRSV) is a significant threat to the pig industry in China. However, the epidemiological characteristics of PRRSV after the outbreak of African swine fever in China were not thoroughly investigated. In the present study, the serological and epidemiological investigations of PRRSV in pigs from the Hunan and Hebei provinces of China were assessed. The results showed that 73.12% (95% CI 71.74-74.49) of pigs were positive for PRRSV-special antibody by enzyme-linked immunosorbent assay. Out of 5799 samples, 482 (8.31%, 95% CI 7.60-9.02) samples were positive for PRRSV nucleic acids. The positive rates of PRRSV in healthy pigs from farms and slaughterhouses were 2.27% (47/2072) and 7.70% (217/2818), which were lower than that in diseased pigs (23.98%, 218/909). Furthermore, the full-length OFR5 gene sequences of 43 PRRSV strains were sequenced and analysed. Phylogenetic analysis revealed that 43 isolates were classified into three lineages, namely lineage 1 (n = 24), lineage 8 (n = 15), and lineage 3 (n = 4). Lineage 1 could be further divided into sublineage 1.5 (n = 2) and sublineage 1.8 (n = 22), and lineage 8 was classified into sublineage 8.1 (n = 3) and sublineage 8.7 (n = 12). Collectively, our findings revealed the severe prevalence of PRRSV in the Hunan and Hebei provinces, where sublineage 1.8 and sublineage 8.7 predominated. The present study provides the update information of the epidemiological and genetic characteristics of PRRSV in the investigated regions, which will be beneficial for PRRS control.

Ventilation Induces Changes in Pulse Wave Transit Time in the Pulmonary Artery.

Pulse wave transit time (PWTT) shortens as pulmonary artery pressure (PAP) increases and was therefore suggested as a surrogate parameter for PAP. The aim of this analysis was to reveal patterns and potential mechanisms of ventilation-induced periodic changes in PWTT under resting conditions. To measure both PWTT and PAP in five healthy pigs, two pulmonary artery Mikro-Tip™ catheters were inserted into the pulmonary vasculature: one with the tip placed in the pulmonary artery trunk, and a second one placed in a distal segment of the pulmonary artery. Animals received pressure-controlled mechanical ventilation. Ventilation-dependent changes were seen in both variables, PWTT and mean PAP; however, changes in PWTT were not synchronous with changes in PAP. Thus, plotting the value of PWTT for each heartbeat over the respective PAP revealed a characteristic hysteresis. At the beginning of inspiration, PAP rose while PWTT remained constant. During further inspiration, PWTT started to decrease rapidly as mPAP was about to reach its plateau. The same time course was observed during expiration: while mPAP approached its minimum, PWTT increased rapidly. During apnea this hysteresis disappeared. Thus, non-synchronous ventilation-induced changes in PWTT and PAP were found with inspiration causing a significant shortening of PWTT. Therefore, it is suggested that the respiratory cycle should be considered when using PWTT as a surrogate for PAP.

Renin-angiotensin-aldosterone system function in the pig-to-baboon kidney xenotransplantation model

After pig-to-baboon kidney transplantation, episodes of hypovolemia and hypotension from an unexplained mechanism have been reported. This study evaluated the renin-angiotensin-aldosterone system post–kidney xenotransplantation. Kidneys from genetically-engineered pigs were transplanted into 5 immunosuppressed baboons after the excision of the native kidneys. Immunosuppressive therapy was based on the blockade of the CD40/CD154 costimulation pathway. Plasma renin, angiotensinogen (AGT), angiotensin II (Ang II), aldosterone levels, and urine osmolality and electrolytes were measured in healthy pigs, healthy nonimmunosuppressed baboons, and immunosuppressed baboons with life-supporting pig kidney grafts. After pig kidney transplantation, plasma renin and Ang II levels were not significantly different, although Ang II trended lower, even though plasma AGT and potassium were increased. Plasma aldosterone levels were unchanged. Urine osmolality and sodium concentration were decreased. Even in the presence of increasing AGT and potassium levels, lower plasma Ang II concentrations may be because of reduced, albeit not absent, the reactivity of pig renin to cleave baboon AGT, suggesting an impaired response of the renin-angiotensin-aldosterone system to hypovolemic and hypotensive episodes. The maintenance of aldosterone may be protective. The reduced urine osmolality and sodium concentration reflect the decreased ability of the pig kidney to concentrate urine. These considerations should not prohibit successful clinical pig kidney xenotransplantation.

Oropharyngeal, proximal colonic, and vaginal microbiomes of healthy Korean native black pig gilts

BackgroundExploring the microbiome in multiple body sites of a livestock species informs approaches to promote its health and performance through efficient and sustainable modulation of these microbial ecosystems. Here, we employed 16S rRNA gene sequencing to describe the microbiome in the oropharyngeal cavity, proximal colon, and vaginal tract of Jeju Black pigs (JBP), which are native to the Korean peninsula.ResultsWe sampled nine 7-month-old JBP gilts raised under controlled conditions. The most abundant phyla that we found within the oropharyngeal microbiota were Proteobacteria, Bacteroidetes, Fusobacteria and Firmicutes, collectively providing core features from twenty-five of their genera. We also found a proximal colonic microbial core composed of features from twenty of the genera of the two predominant phyla, Firmicutes, and Bacteroidetes. Remarkably, within the JBP vaginal microbiota, Bacteroidetes dominated at phylum level, contrary to previous reports regarding other pig breeds. Features of the JBP core vaginal microbiota, came from seventeen genera of the major phyla Bacteroidetes, Firmicutes, Proteobacteria, and Fusobacteria. Although these communities were distinct, we found some commonalities amongst them. Features from the genera Streptococcus, Prevotella, Bacillus and an unclassified genus of the family Ruminococcaceae were ubiquitous across the three body sites. Comparing oropharyngeal and proximal colonic communities, we found additional shared features from the genus Anaerorhabdus. Between oropharyngeal and vaginal ecosystems, we found other shared features from the genus Campylobacter, as well as unclassified genera from the families Fusobacteriaceae and Flavobacteriaceae. Proximal colonic and vaginal microbiota also shared features from the genera Clostridium, Lactobacillus, and an unclassified genus of Clostridiales.ConclusionsOur results delineate unique and ubiquitous features within and across the oropharyngeal, proximal colonic and vaginal microbial communities in this Korean native breed of pigs. These findings provide a reference for future microbiome-focused studies and suggest a potential for modulating these communities, utilizing ubiquitous features, to enhance health and performance of the JBP.

Development, preparation, and evaluation of a novel non-adjuvanted polyvalent dermatophytes vaccine

Ringworm is a worldwide distributed contagious disease infecting both man and animals that constitute an economic, zoonotic, and health problem concern all over the world. During the last decade, attention has been directed to vaccination as an ideal approach to the control of such diseases. In the present study, non-adjuvanted polyvalent vaccines were prepared from locally isolated hot and virulent dermatophyte species, namely Trichophyton verrucosum (T. verrucosum), Trichophyton mentagrophytes (T. mentagrophytes), and Microsporum canis (M. canis) were immunologically evaluated. The prepared vaccine evaluation was focused on the aspects of immunogenicity and protective efficacy using guinea pigs. Both in its living or inactivated forms, the vaccine-induced significant humoral and cell-mediated immune responses and achieve proper protection of guinea pigs against challenging infections with homologous and heterologous dermatophyte strains. On the other hand, investigations on dermatophyte exo-keratinases showed that it was better produced and more expressed in a mineral-based medium containing pure keratin (3 g/L) than in the same medium with human hair supplementation (2.6 g/L). The maximum dermatophyte productivity of exo-keratinases was found to be between 18 and 21 days post-incubation. Using sodium dodecyl sulfate–polyacrylamide gel electrophoresis (SDS-PAGE), two fractions with molecular weights of 40 kDa (fraction I) and 28 kDa (fraction II) have been identified in the culture filtrate of the three involved dermatophyte species. Both fractions demonstrated keratinolytic activity. The specific activity of the isolated keratinases (number of Keratinase units (KU)/mg protein) was stronger in fraction I, where it reached 18.75, 15.38, and 14 KU/mg protein as compared to 12.9, 8.74, and 12 KU/mg protein in fraction II of T. verrucosum, T. mentagrophytes, and M. canis, respectively. The dermatophyte exo-keratinases proved to be immunogenic as they stimulated high keratinase-specific antibody titers and induced strong delayed skin hypersensitivity reactions in vaccinated animals. Anti-keratinase-specific IgG was detected in sera of guinea pigs immunized with the inactivated or living polyvalent dermatophyte vaccines by a homemade enzyme-linked immunosorbent assay (ELISA) using dermatophyte exo-keratinases as coating antigen. The intradermal injection of dermatophyte exo-keratinases induced specific delayed skin reactions in guinea pigs immunized with the inactivated or the living polyvalent dermatophyte vaccines. The intradermal injection of dermatophyte exo-keratinases in the control non-sensitized guinea pigs was associated with itching, swelling, and bloody scar formation, however, no skin indurations were formed. The development of those post-exo-keratinases injection reactions in the control non-sensitized apparently healthy guinea pigs group, suggests an exo-keratinases possible role in the pathogenesis of dermatophytosis.

Exploration of plasma metabolite levels in healthy nursery pigs in response to environmental enrichment and disease resilience.

The purpose of this study was to explore plasma metabolite levels in young healthy pigs and their potential association with disease resilience and estimate genetic and phenotypic correlation with the change in lymphocyte concentration following disease challenge. Plasma samples were collected from 968 healthy nursery pigs over 15 batches at an average of 28 ± 3.23 d of age. Forty-four metabolites were identified and quantified by nuclear magnetic resonance. Pigs were then introduced into a natural disease challenge barn, and were classified into four groups based on the growth rate of each animal in the grow-to-finish phase (GFGR) and treatment rate (TR): resilient (RES), average (MID), susceptible (SUS), and dead (pigs that died before harvest). Blood samples were collected from all pigs before and 2 wk after disease challenge and complete blood count was determined. Environmental enrichment (inedible point source objects) was provided for half of the pigs in seven batches (N = 205) to evaluate its impact on resilience and metabolite concentrations. Concentration of all metabolites was affected by batch, while entry age affected the concentration of 16 metabolites. The concentration of creatinine was significantly lower for pigs classified as "dead" and "susceptible" when compared to "average" (P < 0.05). Pigs that received enrichment had significantly lower concentrations of six metabolites compared with pigs that did not receive enrichment (P ≤ 0.05). Both, group classification and enrichment affected metabolites that are involved in the same pathways of valine, leucine, and isoleucine biosynthesis and degradation. Resilient pigs had higher increase in lymphocyte concentration after disease challenge. The concentration of plasma l-α-aminobutyric acid was significantly negatively genetically correlated with the change in lymphocyte concentration following challenge. In conclusion, creatinine concentration in healthy nursery pigs was lower in pigs classified as susceptible or dead after disease challenge, whilst l-α-aminobutyric may be a genetic biomarker of lymphocyte response after pathogen exposure, and both deserve further investigation. Batch, entry age, and environmental enrichment were important factors affecting the concentration of metabolites and should be taken into consideration in future studies.