Tolerance and Innate Immunity Shape the Development of Postpartum Uterine Disease and the Impact of Endometritis in Dairy Cattle

The Effect of Housing System on Disease Prevalence and Productive Lifespan of Dairy Herds-A Case Study

Selected technological solutions can impact health status of animals. The aim of this case study was to determine the effect of different housing systems on disease prevalence and the productive lifespan of dairy cows. In total, 480 cows kept indoors on one farm in four buildings using four different housing systems (a free-stall barn with a slatted floor; a free-stall barn with a self-cleaning floor; an open-pack barn with deep litter; a tie-stall barn with shallow litter) were analyzed. The data from 6 years, based on veterinary reports, were processed statistically in Statistica 13.00. The study demonstrated that the average productive lifespan was longer (p ≤ 0.01), by up to more than 8 months, in the system with deep litter, which was also characterized by the lowest disease prevalence (p ≤ 0.01), especially foot and some reproductive disorders. This trend was maintained in each year of the study period (2015-2020). In the tie-stall barn, the prevalence of mastitis was reduced, but the risk of lameness, retained placenta, parturient paresis and displaced abomasum was higher in this system (p ≤ 0.01). Overall morbidity was highest in the free-stall barns. Lower morbidity was associated with an increase in productive herd life.

IFN-τ mediated miR-26a targeting PTEN to activate PI3K/AKT signalling to alleviate the inflammatory damage of bEECs

Endometritis is the failure of embryo implantation and an important cause of infertility in dairy cows. IFN-τ is a type I interferon unique to ruminants. In regulating the process of inflammatory response, IFN-τ can be expressed through MicroRNAs (miRNAs) to regulate the process of inflammation. However, IFN-τ regulates lipopolysaccharide (LPS)-induced inflammatory injury of bEECs through the highly conserved miR-26a in mammals, and the mechanism remains unclear. Bovine endometrial epithelial cells (bEECs)were isolated and cultured to establish an inflammatory injury model. RT–qPCR and ELISA were used to detect the secretion of inflammatory factors. Dual-luciferase assays and target gene silencing assays determine the regulatory role of miRNAs. The target protein was detected by immunofluorescence and western blotting. This study showed that the expression of miR-26a was significantly down-regulated in mouse endometrium inflammatory injury tissue and LPS stimulated bEECs; and IFN-τ reversed the expression of miR-26a. The study also showed that the overexpression of miR-26a significantly inhibited the secretion of pro-inflammatory cytokines IL-1β, IL-6 and TNF-α. In addition, studies have shown that miR-26a inhibits its translation by targeting PTEN 3′-UTR, which in turn activates the Phosphatidylinositide 3-kinases/protein kinase B (PI3K/AKT) pathway, so that nuclear factor kappa-B (NF-κB) signaling is inhibited. In summary, the results of this study further confirm that IFN-τ as an anti-inflammatory agent can up-regulate the expression of miR-26a and target the PTEN gene to inhibit the inflammatory damage of bEECs.

Effect of retained placenta and clinical mastitis on reproduction parameters, immune response, and steroidogenic receptors gene expression in postpartum crossbred dairy cows

The purpose of this study was to evaluate the effect of retained placenta (RP) and clinical mastitis (CM) on the reproductive efficiency of crossbred dairy cows during the postpartum period and the effect in some innate immune system indicators. For this, two experiments were carried out. In the first, a total of 232 cows were evaluated and divided as: healthy control (n = 184), RP (n = 22), and CM (n = 26) groups. The RP and CM was evaluated until 30 days postpartum (DPP) and reproductive rates were measured. In experiment 2, cows were divided in control (n = 10), RP (n = 10), and CM (n = 30) groups. Between 40 and 50 DPP, clinical, gynecological examination and endometrial cytobrush were performed to evaluate subclinical endometritis (SE) and gene expression of interleukins 1β (IL-1β) and 6 (IL-6), chemokine ligand 5 (CCL5), estrogen α (ESR1), and progesterone (PGR) receptors by qRT-PCR analysis. In experiment 1, the conception rate at 1st artificial insemination (AI) was lower in RP and CM groups and pregnancy rate at 150 days decreased in CM group. Calving-to-1st AI interval and days open were shorter in healthy cows. In experiment 2, the occurrence of SE was 26.7% and higher in RP and CM groups. The expression of IL-1β increased in RP and CM groups, while IL-6 was less expressed in RP group. The CCL5, ESR1, and PGR were similar between groups. In conclusion, cows with RP and CM had their reproductive efficiency negatively affected and had they initial pro-inflammatory response improved by the increase of IL-β.

Heritability of subclinical endometritis in Norwegian Red cows

Subclinical endometritis (SCE) is highly prevalent in dairy cows, causing negative effects on reproductive outcomes and the producer economy. Genetic selection for animals with better resilience against uterine disease should be prioritized due to both sustainability and animal welfare. Therefore, the aim of the present study was to estimate the heritability of SCE in the Norwegian Red (NR) population. Moreover, future perspectives of the condition as a fertility phenotype for breeding are discussed. A total of 1,642 NR cows were sampled for SCE at the time of artificial insemination, using cytotape. The percentage of polymorphonuclear cells (PMN) in each sample was established by cytology, through the counting of 300 PMN and epithelial cells. The mean percentage of PMN was 5%. Different trait definitions were examined, and SCE was defined as binary traits, based on the following cut-off levels of PMN: Cyto0 = PMN >0, Cyto3 = PMN >3%, Cyto5 = PMN >5%, Cyto10 = PMN >10%, and Cyto20 = PMN >20%. The mean ranged from 0.07 (Cyto20) to 0.59 (Cyto0). We also analyzed PMN as a continuous variable using percent PMN. Information on the animals and herds was obtained from the Norwegian Dairy Herd Recording System. The pedigree of cows with data included a total of 24,066 animals. A linear animal model was used to estimate the heritability. The only trait definition that had an estimated genetic variance larger than the standard error was Cyto5, with an estimated heritability of 0.04. For all other definitions, the genetic variance was not significantly different from zero. A cut-off level of 5% PMN has been established as a general threshold for the definition of SCE in earlier literature. The standard errors of the estimated variance components were relatively large, and results should be interpreted with caution. However, the current study indicates that SCE is heritable at a similar level to that of clinical endometritis and metritis, and has potential as a future fertility phenotype to be used for breeding purposes. A more feasible method to diagnose SCE is needed to establish larger data sets.

A Genome-Wide Association Study for Tolerance to Paratuberculosis Identifies Candidate Genes Involved in DNA Packaging, DNA Damage Repair, Innate Immunity, and Pathogen Persistence

Although the genetic susceptibility to diseases has been extensively studied, the genetic loci and the primary molecular and cellular mechanisms that control disease tolerance are still largely unknown. Bovine paratuberculosis (PTB) is an enteritis caused by Mycobacterium avium subsp. paratuberculosis (MAP). PTB affects cattle worldwide and represents a major issue on animal health. In this study, the associations between host genetic and PTB tolerance were investigated using the genotypes from 277 Spanish Holstein cows with two distinct phenotypes: cases) infected animals with positive PCR and bacteriological culture results but without lesions in gut tissues (N= 24), and controls) animals with negative PCR and culture results but with PTB-associated lesions (N= 253). DNA from peripheral blood of the study population was genotyped with the Bovine EuroG MD Bead Chip, and the corresponding genotypes were imputed to whole-genome sequencing (WGS) data. A genome-wide association study was performed using the WGS data and the defined phenotypes in a case-control approach. A total of 142 single nucleotide polymorphisms (SNPs) were associated (false discovery rate ≤ 0.05, P values between 1.5 × 10^-7 and 5.7 × 10^-7) with tolerance (heritability= 0.55). The 40 SNPs with P-values < 5 × 10^-7 defined 9 QTLs and 98 candidate genes located on BTA4, BTA9, BTA16, BTA25, and BTA26. Some of the QTLs identified in this study overlap with QTLs previously associated with PTB, bovine tuberculosis, mastitis, somatic cell score, bovine diarrhea virus persistent infection, tick resistance, and length of productive life. Two candidate genes with important roles in DNA damage response (ERCC4 and RMI2) were identified on BTA25. Functional analysis using the 98 candidate genes revealed a significant enrichment of the DNA packaging process (TNP2/PRMI1/PRM2/PRM3). In addition, the TNF-signaling (bta04668; TRAF5/CREB5/CASP7/CHUK) and the toxoplasmosis (bta05145; TGFβ2/CHUK/CIITA/SOCS1) pathways were significantly enriched. Interestingly, the nuclear Factor NF-κβ Inhibitor Kinase Alpha (CHUK), a key molecule in the regulation of the NF-κB pathway, was enriched in both pathways. Taken together, our results define a distinct immunogenetic profile in the PTB-tolerant animals designed to control bacterial growth, modulate inflammation, limit tissue damage and increase repair, thus reducing the severity of the disease.

The endometrial transcriptomic response to pregnancy is altered in cows after uterine infection

Pregnancy induces changes in the transcriptome of the bovine endometrium from 15 days after insemination. However, pregnancy is less likely to occur if cows had a postpartum bacterial infection of the uterus, even after the resolution of disease. We hypothesized that uterine bacterial infection alters the endometrial transcriptomic signature of pregnancy after the resolution of disease. To examine the endometrial transcriptomic signature of pregnancy, cows were inseminated 130 days after intrauterine infusion of pathogenic Escherichia coli and Trueperella pyogenes, subsequently endometrium was collected 16 days after insemination for RNA sequencing. We found 171 pregnancy regulated genes in cows 146 days after bacterial infection. When comparing our findings with previous studies that described the endometrial transcriptomic signature of pregnancy in healthy cows, 24 genes were consistently differentially expressed in pregnancy, including MX1, MX2 and STAT1. However, 12 pregnancy regulated genes were found only in the endometrium of healthy cows, including ISG15 and TRANK1. Furthermore, 28 pregnancy regulated genes were found only in the endometrium of cows following bacterial infection and these were associated with altered iNOS, TLR, and IL-7 signaling pathways. Although 94 predicted upstream regulators were conserved amongst the studies, 14 were found only in the endometrium of pregnant healthy cows, and 5 were found only in cows following bacterial infection, including AIRE, NFKBIA, and DUSP1. In conclusion, there were both consistent and discordant features of the endometrial transcriptomic signature of pregnancy 146 days after intrauterine bacterial infusion. These findings imply that there is an essential transcriptomic signature of pregnancy, but that infection induces long-term changes in the endometrium that affect the transcriptomic response to pregnancy.

Staphylococcus aureus Induces Goat Endometrial Epithelial Cells Apoptosis via the Autophagy and Endoplasmic Reticulum Stress Pathway

Simple Summary

The toxicity mechanism of Staphylococcus aureus on goat endometrial epithelial cells (gEECs) is still unelucidated. The purpose of this experiment was to investigate the molecular mechanism of gEECs death caused by S. aureus in terms of autophagy and endoplasmic reticulum (ER) stress. We found that the accumulation of autophagosomes exacerbated S. aureus-induced gEECs apoptosis, and that ER stress was involved in the regulation of the autophagy. These findings may provide new insight into the therapeutic target of endometrial cell injury.

Abstract

Increasing evidence indicates that autophagy and endoplasmic reticulum (ER) stress are involved in the regulation of cell death; however, the role of autophagy and ER stress in Staphylococcus aureus-induced endometrial epithelial cell damage is still unelucidated. In the present study, our results showed that infection with S. aureus increased the cytotoxicity and the protein expression of Bax, caspase-3, and cleaved-PARP-1 in goat endometrial epithelial cells (gEECs). Moreover, after infection, the expression of LC3II and autophagosomes were markedly increased. The autophagosome inhibitor 3-methyladenine (3-MA) significantly decreased the cytotoxicity and the expression of caspase-3, and cleaved-PARP-1; however, the autophagosome–lysosome fusion inhibitor chloroquine (CQ) increased their expression. Additionally, the protein expression of GRP78, EIF2α, and ATF4 were also markedly increased after infection. The ER stress inhibitor 4-PBA decreased the cytotoxicity and the expression of LC3II and apoptosis-related proteins in S. aureus-infected gEECs. Collectively, our findings prove that the accumulation of autophagosomes exacerbated S. aureus-induced gEECs apoptosis, and that ER stress was involved in the regulation of the autophagy and apoptosis.

Comparative gene expression profile in circulating PBMCs of Bos indicus and crossbred cattle to understand disease tolerance mechanism

The present investigation was performed to compare the global gene expression profile in peripheral blood mononuclear cells (PBMCs) of Bos indicus and crossbred (Bos taurus × B. indicus) cattle. Previously, several studies revealed the disease tolerance potential of B. indicus cattle but underlying genetic mechanism is still not fully explored. The PBMCs model was used for this investigation as it plays crucial role in the immune system regulation. Transcriptomic analysis revealed total 6767 significantly differentially expressed transcripts (fold change (absolute) >2.0, p < .05). In addition, 4149 transcripts were upregulated, 2618 transcripts were downregulated and fold change (absolute) of differentially expressed transcript varied from -223.32 to 213.63. Functional annotation analysis of differentially expressed genes confirmed their role in various molecular pathways viz. innate immune response, antigen processing and presentation, MHC protein complex, defense response to bacterium, regulation of immune response, positive regulation of JAK-STAT cascade, cytoskeletal protein binding, etc. Protein-protein interaction network analysis provided understanding of inter-relationship of immune genes with differentially expressed genes. In conclusion, this study could provide comprehensive information about the dysregulated genes and biological pathways in PBMCs which might be responsible for disease tolerance in B. indicus cattle.

The Antioxidant Role of Selenium via GPx1 and GPx4 in LPS-Induced Oxidative Stress in Bovine Endometrial Cells

This study investigated the antioxidant role of selenium (Se) in the form of selenomethionine (SLM) in LPS-induced oxidative stress via the glutathione peroxidase (GPx) enzymes and the Nrf2/HO-1 transcription factor. The impact of serum supplementation in culture media on GPxs was also studied. The bovine uterus is constantly exposed to exogenous pathogens postpartum, and the endometrium is the first contact against bacteria invasion. Endometritis is an inflammation of the endometrium and is brought about by bacterial lipopolysaccharide capable of inducing oxidative stress. The BEND cells were supplemented at the point of seeding with the following SLM concentrations 0, 100, 500, and 1000 nM for 48 h. BEND cells, cultured with or without SLM (100 nM), were initially incubated for 48 h, and then, we serum starved the SLM group for 24, 48, and 72 h. Similarly, an assay involving serum volume (0, 2, 5, and 10%) supplementation in culture media (v/v) with or without SLM (100 nM) was performed for 48 h. The BEND cells were also seeded into four experimental groups and cultured for an initial 48 h as follows: control, LPS (20 μg/mL), SLM (100 nM), and SLM + LPS groups followed by 6-h LPS treatment. The role of SLM in modulating the expressions of GPx1 and GPx4 and the Nrf2 transcription factor-related genes was assessed using qRT-PCR and Western blot techniques. The results showed serum starvation in the presence of SLM supplementation decreased the expression of GPx1 enzyme but increased GPx4 compared to the control. The addition of SLM to cell culture media in an FBS limiting condition improved the expressions of both GPx1 and GPx4. SLM supplementation promoted GPx enzymes' expressions in a serum-free media (0%) and at 2% FBS in media. However, it did not improve their expressions at 10% FBS in media than the untreated groups. Together, our data show the protective role of Se by regulating the expressions of GPx1 and GPx4 enzymes in BEND cells. It also shows that SLM promoted the expression of Nrf2 transcription factor-related genes at both the mRNA and protein levels in BEND cells during LPS stimulation.

A Review of the Diversity of the Genital Tract Microbiome and Implications for Fertility of Cattle

Cattle have a genital microbiome that is established early in life, even before calving. Microbial influx into the reproductive system of cows, during calving or mating, is unavoidable and is likely to alter the commensal microflora composition. It is now well established that a commensal endometrial flora is largely responsible for the overall fertility of cows. These microbes are important for maintenance of structural integrity of the genital mucosal barrier, immunomodulation, and protection against pathogens. Further, the genital microbiome functions in the semiochemical communication between a male and female. An optimal balance between the abundance and diversity of the microbiome is essential to promote female genital tract health. Disruption of this balance leads to dysbiosis and genital diseases and perturbed fertility. As part of the global strategy of One World, One Health, there is a need to reduce antibiotic use in animals. This area of research has the potential to expand the knowledge about the nexus between the endometrial microbiome and fertility including being probiotic in different species.

Progesterone differentially affects the transcriptomic profiles of cow endometrial cell types

Background

The endometrium is a heterogeneous tissue composed of luminal epithelial (LE), glandular epithelial (GE), and stromal cells (ST), experiencing progesterone regulated dynamic changes during the estrous cycle. In the cow, this regulation at the transcriptomic level was only evaluated in the whole tissue. This study describes specific gene expression in the three types of cells isolated from endometrial biopsies following laser capture microdissection and the transcriptome changes induced by progesterone in GE and ST cells.

Results

Endometrial LE, GE, and ST cells show specific transcriptomic profiles. Most of the differentially expressed genes (DEGs) in response to progesterone are cell type-specific (96%). Genes involved in cell cycle and nuclear division are under-expressed in the presence of progesterone in GE, highlighting the anti-proliferative action of progesterone in epithelial cells. Elevated progesterone concentrations are also associated with the under-expression of estrogen receptor 1 (ESR1) in GE and oxytocin receptor (OXTR) in GE and ST cells. In ST cells, transcription factors such as SOX17 and FOXA2, known to regulate uterine epithelial-stromal cross-talk conveying to endometrial receptivity, are over-expressed under progesterone influence.

Conclusions

The results from this study show that progesterone regulates endometrial function in a cell type-specific way, which is independent of the expression of its main receptor PGR. These novel insights into uterine physiology present the cell compartment as the physiological unit rather than the whole tissue.

Supplementary Information

The online version contains supplementary material available at 10.1186/s12864-022-08323-z.

Milk production status and associated factors among indigenous dairy cows in Raya Kobo district, north eastern Ethiopia

Background

Result

Conclusion

Effects of a single transdermal administration of flunixin meglumine in early postpartum Holstein Friesian dairy cows: Part 1. Inflammatory and metabolic markers, uterine health, and indicators of pain

The objectives of this study were to assess the effects of a single transdermal administration of flunixin meglumine (FM) in early postpartum Holstein Friesian dairy cows on serum concentrations of inflammatory and metabolic markers, uterine health, and indicators of pain. The hypothesis was that the anti-inflammatory, antipyretic, and analgetic effects of the pharmaceutic agent would reduce systemic inflammation, resulting in improved metabolic and inflammatory profile, diminished incidence of metritis, and reduced expression of pain. A total of 500 cows (153 primiparous, 347 multiparous) from 3 different commercial dairy farms in the northeast of Germany were included in a randomized controlled clinical trial. Farms were preselected based on high haptoglobin concentrations in their fresh lactating cows. Cows were excluded if they had experienced dystocia, stillbirth, or twin birth, or if they showed any signs of milk fever, retained fetal membranes, or fever (>40°C). The cows were treated once with either FM (3.33 mg/kg) or a placebo as control (CON) through transdermal administration between 24 to 36 h postpartum (d 2). General health examinations were performed (daily from d 2-8 and additionally on d 15 postpartum), vaginal discharge was assessed using the Metricheck device (d 8 and 15 postpartum) and serum samples were analyzed for inflammatory and metabolic markers (d 2, 4, and 6 postpartum). Effects of treatment, parity, sampling day, and their interactions were evaluated using mixed effects models. Primiparous cows treated with FM showed lower serum haptoglobin concentrations (0.90 ± 0.08 vs. 1.17 ± 0.07 g/L; ± standard error of the mean) and higher serum albumin concentrations (35.5 ± 0.31 vs. 34.8 ± 0.31 g/L) on d 6 postpartum. They also had a lower risk for purulent vaginal discharge with or without a fever compared with CON cows on d 15 postpartum (odds ratio for CON vs. FM: 1.63, 95% CI: 1.26-2.00), and body temperature was lower throughout the first 15 d in milk (39.1 ± 0.11 vs. 39.2 ± 0.11°C). Multiparous cows treated with FM had lower serum β-hydroxybutyrate concentrations on d 4 postpartum (0.71 ± 0.05 vs. 0.78 ± 0.05 mmol/L) and d 6 postpartum (0.74 ± 0.05 vs. 0.80 ± 0.05 mmol/L). Regardless of parity, FM-treated cows were significantly less likely to abduct their tail from their body (14.3 vs. 23.6%) and show an arched back (27.9 vs. 39.7%) on the day after treatment compared with CON cows. It can be concluded that FM treatment slightly reduced inflammation and diminished the risk for metritis in primiparous cows, improved metabolic profile in multiparous cows, and reduced expressions of pain in all cows.

Dietary β-Carotene on Postpartum Uterine Recovery in Mice: Crosstalk Between Gut Microbiota and Inflammation

As the precursor of vitamin A, β-carotene has a positive effect on reproductive performance. Our previous study has shown that β-carotene can increase antioxidant enzyme activity potentially through regulating gut microbiota in pregnant sows. This study aimed to clarify the effect of β-carotene on reproductive performance and postpartum uterine recovery from the aspect of inflammation and gut microbiota by using a mouse model. Twenty-seven 6 weeks old female Kunming mice were randomly assigned into 3 groups (n=9), and fed with a diet containing 0, 30 or 90 mg/kg β-carotene, respectively. The results showed that dietary supplementation of β-carotene reduced postpartum uterine hyperemia and uterine mass index (P<0.05), improved intestinal villus height and villus height to crypt depth ratio, decreased serum TNF-α and IL-4 concentration (P<0.05), while no differences were observed in litter size and litter weight among three treatments. Characterization of gut microbiota revealed that β-carotene up-regulated the relative abundance of genera Akkermansia, Candidatus Stoquefichus and Faecalibaculum, but down-regulated the relative abundance of Alloprevotella and Helicobacter. Correlation analysis revealed that Akkermansia was negatively correlated with the IL-4 concentration, while Candidatus Stoquefichus and Faecalibaculum had a negative linear correlation with both TNF-α and IL-4 concentration. On the other hand, Alloprevotella was positively correlated with the TNF-α, and Helicobacter had a positive correlation with both TNF-α and IL-4 concentration. These data demonstrated that dietary supplementation of β-carotene contributes to postpartum uterine recovery by decreasing postpartum uterine hemorrhage and inhibiting the production of inflammatory cytokines potentially through modulating gut microbiota.

Effects of feeding rumen-protected linseed fat to postpartum dairy cows on plasma n-3 polyunsaturated fatty acid concentrations and metabolic and reproductive parameters

High-yielding dairy cows experience a negative energy balance and inflammatory status during the transition period. Fat supplementation increases diet energy density, and plasma n-3 polyunsaturated fatty acids (PUFA) have been proposed to improve immune function. This study tested the hypothesis that dietary supplementation with a rumen-protected and n-3 PUFA-enriched fat could ameliorate both the energetic deficit and immune status of postpartum high-yielding dairy cows, improving overall health and reproductive efficiency. At 11 d in milk (DIM), cows were randomly allocated to groups (1) n-3 PUFA (n = 29), supplemented with encapsulated linseed oil supplying additional up to 64 g/d (mean 25 ± 4 g/d) of α-linolenic acid (ALA), or (2) control (n = 31), supplemented with hydrogenated palm oil without ALA content. Fat supplements of the n-3 PUFA and control groups were available through an automated, off-parlor feeding system, and intake depended on the cow's feeding behavior. Plasma ALA concentrations were higher in n-3 PUFA than control cows, following a linear relation with supplement ingestion, resulting in a lower n-6/n-3 ratio in plasma. Metabolic parameters (body condition score and glucose and β-hydroxybutyric acid blood concentrations) were unaffected, but milk yield improved with increased intake of fat supplements. Plasma total adiponectin concentrations were negatively correlated with ingestion of n-3 PUFA-enriched fat supplement, following a linear relation with intake. Conception rate to first AI increased with higher intake of both fats, but a decrease of calving-to-conception interval occurred only in n-3 PUFA cows. Postpartum ovarian activity and endometrial inflammatory status at 45 DIM were unaffected. In conclusion, this study evinced a positive linear relation between rumen-protected linseed fat intake and plasma n-3 PUFA concentrations, which modulated adiponectin expression and improved reproductive parameters.

Tanshinone ⅡA inhibits the lipopolysaccharide-induced epithelial-mesenchymal transition and protects bovine endometrial epithelial cells from pyolysin-induced damage by modulating the NF-κB/Snail2 signaling pathway

Mixed infection with Escherichia coli and Trueperella pyogenes (T. pyogenes) leads to purulent endometritis, but the underlying molecular mechanisms remain unclear. The aim of this study was to investigate the effect of tanshinone ⅡA (Tan ⅡA) on E. coli and T. pyogenes -induced purulent endometritis and explore the underlying mechanism. First, lipopolysaccharide (LPS) isolated from E. coli and bacteria-free filtrates (BFFs) isolated from T. pyogenes were used to induce a model of bovine endometrial epithelial cell (bEEC) damage in vitro. bEECs were pretreated with or without Tan ⅡA for 2 h, before LPS and BFFs were introduced to induce damage to investigate the protective effect of Tan IIA. Then, the cytolytic activity and inflammatory response in bEECs were examined using CCK-8, LDH and RT-qPCR assays. Furthermore, we confirmed the molecular mechanism by which Tan ⅡA reversed the damaged phenotypes in LPS- and BFFs-induced bEECs via the NF-κB/Snail2 pathway using qPCR and Western blotting. Tan ⅡA significantly decreased the cytolytic activity and inflammatory response in LPS- and BFFs-induced bEECs. In addition, Tan ⅡA reversed the dysregulation of E-cadherin, N-cadherin and vimentin. Moreover, Tan ⅡA significantly inhibited the activation of the NF-κB signaling pathway and decreased the expression level of Snail2, which is the main regulator of the epithelial-mesenchymal transition (EMT). In summary, Tan ⅡA inhibits the LPS-induced EMT and protects bEECs from pyolysin-induced damage by modulating the NF-κB/Snail2 signaling pathway.

Oxysterols protect bovine endometrial cells against pore-forming toxins from pathogenic bacteria

Many species of pathogenic bacteria secrete toxins that form pores in mammalian cell membranes. These membrane pores enable the delivery of virulence factors into cells, result in the leakage of molecules that bacteria can use as nutrients, and facilitate pathogen invasion. Inflammatory responses to bacteria are regulated by the side-chain-hydroxycholesterols 27-hydroxycholesterol and 25-hydroxycholesterol, but their effect on the intrinsic protection of cells against pore-forming toxins is unclear. Here, we tested the hypothesis that 27-hydroxycholesterol and 25-hydroxycholesterol help protect cells against pore-forming toxins. We treated bovine endometrial epithelial and stromal cells with 27-hydroxycholesterol or 25-hydroxycholesterol, and then challenged the cells with pyolysin, which is a cholesterol-dependent cytolysin from Trueperella pyogenes that targets these endometrial cells. We found that treatment with 27-hydroxycholesterol or 25-hydroxycholesterol protected both epithelial and stomal cells against pore formation and the damage caused by pyolysin. The oxysterols limited pyolysin-induced leakage of potassium and lactate dehydrogenase from cells, and reduced cytoskeletal changes and cytolysis. This oxysterol cytoprotection against pyolysin was partially dependent on reducing cytolysin-accessible cholesterol in the cell membrane and on activating liver X receptors. Treatment with 27-hydroxycholesterol also protected the endometrial cells against Staphylococcus aureus α-hemolysin. Using mass spectrometry, we found 27-hydroxycholesterol and 25-hydroxycholesterol in uterine and follicular fluid. Furthermore, epithelial cells released additional 25-hydroxycholesterol in response to pyolysin. In conclusion, both 27-hydroxycholesterol and 25-hydroxycholesterol increased the intrinsic protection of bovine endometrial cells against pore-forming toxins. Our findings imply that side-chain-hydroxycholesterols may help defend the endometrium against pathogenic bacteria.

Effects of dietary starch content and body condition score at calving on reproductive parameters in Holstein dairy cows

Nutritional modifications can potentially impact the reproductive performance and ultimately the economic results of dairy herds. The objectives were to investigate the effects of feeding a high starch (HS) diet and body condition score (BCS) at calving on reproductive responses and uterine health in Holstein dairy cows. One hundred seventy-four multiparous cows were randomly assigned to 1 of 2 experimental diets from 16 until 50 days in milk (DIM; n = 87 per group); normal starch (228 g/kg diet DM; NS) or high starch (270 g/kg diet DM; HS) diets. Each dietary treatment group was further subdivided based on BCS at calving as normal BCS (BCS ≤ 3.5; NBCS; n = 45) and high BCS (BCS ≥ 3.75; HBCS; n = 42). Transrectal ultrasonography was carried out at 10 DIM, and thereafter twice weekly until the onset of ovarian cyclicity or d 50 DIM. Feeding HS diet significantly affected the proportion of cows cycling by 30 and 40 DIM. Number of services per conception and calving interval (CI) were significantly improved in cows fed the HS compared to the NS diet (2.08 vs. 2.51 and 427.14 vs. 445.30 days for cows fed HS and NS diets, respectively). In summary, feeding higher starch diets from 16 till 50 DIM could be an effective strategy to improve the economic variables related to reproduction in dairy cows.

ISGylation Inhibits an LPS-Induced Inflammatory Response via the TLR4/NF-κB Signaling Pathway in Goat Endometrial Epithelial Cells

Simple Summary

Endometritis is a common and important reproductive disease of domestic animals, leading to repeated infertility, abortion, and ovarian dysfunction, which affects the reproductive rate and production performance of female domestic animals, and causes serious financial loss to farmers. Infection with Gram-negative bacteria, the release of LPS and activation of the TLR4/NF-κB signaling pathway are the principal factors responsible for the disease. However, the mechanism of the interaction between endometrial immunity and bacterial infection is not entirely clear. Ubiquitin-like protein ISG15 can regulate the TLR4/NF-κB signaling pathway via the ISGylation modification system, which modulates the inflammatory response. In the present study, we found that ISG15 proteins were mainly located in the cytoplasm of goat endometrial epithelial cells (gEECs) and that the expression of key genes and proteins of ISGylation increased in LPS-induce gEECs. Overexpression and silencing of the ISG15 gene demonstrated that ISGylation inhibited an LPS-induced inflammatory response via the TLR4/NF-κB signaling pathway in gEECs. Here, we provide the experimental basis for further exploration of the role of the ISGylation modification system in the inflammatory response of endometrium and a potential method for the treatment of endometritis.

Abstract

Endometritis is a common and important reproductive disease of domestic animals. The principal factors responsible for the disease are infection with Gram-negative bacteria, the release of Lipopolysaccharides (LPS) and activation of the TLR4/NF-κB signaling pathway. However, we do not fully understand the interaction between endometrial immunity and bacterial infection in the disease etiology. The ubiquitin-like protein ISG15 can regulate the TLR4/NF-κB signaling pathway via the ISGylation modification system, modulating the inflammatory response. In the present study, we found that ISG15 protein was expressed mainly in the cytoplasm of goat endometrial epithelial cells (gEECs) and that the expression of key genes and proteins of ISGylation increased in LPS-induced gEECs. Overexpression and silencing of the ISG15 gene demonstrated that ISGylation inhibited an LPS-induced inflammatory response via the TLR4/NF-κB signaling pathway in gEECs. Here, we provide the experimental basis for further exploration of the role of the ISGylation modification system in the inflammatory response of endometrium and a potential method for the treatment of endometritis.

Effects of Resveratrol on Receptor Expression and Serum Levels of Estrogen and Progesterone in the Rat Endometritis Model

Endometritis is characterized by inflammation of the endometrial lining that leads to reduced reproductive potential. Restoring the impaired hormonal balance is an important component of endometritis treatment. The purpose of the current study was to evaluate the effects of resveratrol on estrogen and progesterone hormone status in endometritis. Mature female Sprague Dawley rats were used, and endometritis was induced by intrauterine infusion of Escherichia coli. Animals were treated with resveratrol alone or combined with marbofloxacin. Compared to the non-treated endometritis group, resveratrol treatment reduced serum oestradiol levels, increased serum progesterone levels, enhanced estrogen receptor (ER) expression in the uterine stroma, decreased ESR1 gene expression, and raised ESR2 gene expression. Resveratrol administration combined with marbofloxacin also increased ER expression in the uterine gland and progesterone receptor expression in the uterine epithelium. The findings of this study suggest that the actions of resveratrol on progesterone levels and estrogen receptor expression might be responsible for its beneficial effect in rats with endometritis.

Development of an intrauterine infection model in the postpartum dairy cow

AIMS

To develop an intrauterine infection model for Trueperella pyogenes in postpartum dairy cows and to assess the effect of this infection on the degree of intrauterine inflammation and concentrations of progesterone in serum.

METHODS

The oestrous cycles of 36 healthy, non-pregnant, postpartum dairy cows were synchronised. They were then treated by intrauterine infusion of 0.5 g cephapirin before being blocked by age and randomly assigned to treatment with intrauterine infusion of saline (n = 18), 10⁷ (n = 9) or 10⁹ (n = 9) cfu of T. pyogenes, approximately 4 days after the expected time of ovulation (Day 0). Prior to intrauterine infusion on Day 0 and again on Days 3, 7, 10, and 15, cytobrush samples were collected from the uterus of each cow for microbiology and assessment of the percentage of polymorphonuclear neutrophils (PMN%). Blood samples were collected on the same days for measurement of concentrations of progesterone in serum, and uterine lumen diameter was assessed daily using transrectal ultrasonography.

RESULTS

Trueperella pyogenes was isolated from 5/18 (28%), 7/9 (78%) and 8/9 (89%) cows infused with saline, 10⁷ or 10⁹ cfu of T. pyogenes, respectively (p < 0.001). Mean PMN% in the control cows did not change over time (p > 0.05), whereas it was higher on Days 7 and 10 than Day 0 in the 10⁷ cfu group, and higher on Days 3 and 10 than Day 0 in the 10⁹ cfu group (p < 0.05). The percentage of observations with uterine lumen diameters >2 mm was higher in cows infused with 10⁷ (29.3 (95% CI = 14.5-44.2)%) or 10⁹ cfu (19.2 (95% CI = 7.0-31.5)%) than in control cows (3.1 (95% CI = 0.1-6.0)%) (p < 0.001). Mean concentrations of progesterone in serum were higher in cows infused with 10⁷ cfu (2.01 (SE 0.19) ng/mL) than cows infused with 10⁹ cfu (1.01 (SE 0.27) ng/mL), with the control group intermediate (1.41 (SE 0.19) ng/mL) (p = 0.03).

CONCLUSIONS

Infusion of 10⁷ or 10⁹ cfu of T. pyogenes resulted in the establishment of intrauterine infection in 83% of cows. Infection resulted in increased uterine lumen diameter, and an inflammatory response, i.e. elevated PMN%.

CLINICAL RELEVANCE

This intrauterine infection model may be useful for future research on, for example, the pathogenesis of intrauterine infection in postpartum dairy cows.

Methionine supply during the peripartum period and early lactation alter immunometabolic gene expression in cytological smear and endometrial tissue of holstein cows

The objective of the present study was to evaluate the effect of feeding rumen-protected methionine (RPM) during the peripartal period and early lactation on mRNA gene expression profiles of uterine cytological smear and endometrial samples of Holstein cows (n = 20). Treatments consisted of a supplementation with RPM [MET; n = 11; RPM at a rate of 0.08 % of DM: Lys:Met = 2.8:1, (Smartamine® M Adisseo, Alpharetta, GA, USA)] and no supplementation (CON; n = 9; Lys:Met = 3.5:1). Uterine cytology smears and endometrial samples were collected at 15, 30, and 73 days in milk (DIM) and analyzed for expression of genes related with metabolism, inflammation, and methionine metabolism. Regarding the cytological smear samples, RPM supplementation tended to increase mRNA expression of methionine adenosyltransferase 1 alpha (MAT1A) and increased the mRNA expression of fibroblast growth factor 7 (FGF7), with an effect of time for the latter. On the other hand, RPM decreased mRNA expression for glucose transporter 4 (GLUT4), interleukin 1 beta (IL-1β), interleukin 6 (IL-6), interleukin 8 (IL-8), prostaglandin E synthase 3 (PTGES3), translocator protein 18 kDa (TSPO), mucin 1 (MUC1) and superoxide dismutase (SOD1) in cytological smear samples. There was an effect of time for all variables except MAT1A, with decreasing expression over time. There was a TRT × TIME interaction for GLUT4 mRNA expression, with higher GLUT4 mRNA expression for cows fed CON than for cows fed RPM at time 15 and a tendency to higher expression for cows fed CON on time 30 when compared with cows fed RPM. For uterine tissue samples, feeding RPM increased the mRNA expression of lecithin-cholesterol acyltransferase (LCAT), S-adenosyl-l-homocysteine hydrolase (SAAH), FGF7, GLUT4, and apolipoproteins 3 (APOL3), with an effect of time for APOL3 where its expression increased over time. There was a tendency for cows fed RPM to have decreased IL1β mRNA expression. In conclusion, feeding RPM during transition period and early lactation is beneficial for uterine immune response and metabolism in early lactation as indicated by the favorable expressions of genes affecting the uterine immunometabolism during such a challenging period.

Bisphosphonate inhibitors of squalene synthase protect cells against cholesterol-dependent cytolysins

Certain species of pathogenic bacteria damage tissues by secreting cholesterol-dependent cytolysins, which form pores in the plasma membranes of animal cells. However, reducing cholesterol protects cells against these cytolysins. As the first committed step of cholesterol biosynthesis is catalyzed by squalene synthase, we explored whether inhibiting this enzyme protected cells against cholesterol-dependent cytolysins. We first synthesized 22 different nitrogen-containing bisphosphonate molecules that were designed to inhibit squalene synthase. Squalene synthase inhibition was quantified using a cell-free enzyme assay, and validated by computer modeling of bisphosphonate molecules binding to squalene synthase. The bisphosphonates were then screened for their ability to protect HeLa cells against the damage caused by the cholesterol-dependent cytolysin, pyolysin. The most effective bisphosphonate reduced pyolysin-induced leakage of lactate dehydrogenase into cell supernatants by >80%, and reduced pyolysin-induced cytolysis from >75% to <25%. In addition, this bisphosphonate reduced pyolysin-induced leakage of potassium from cells, limited changes in the cytoskeleton, prevented mitogen-activated protein kinases cell stress responses, and reduced cellular cholesterol. The bisphosphonate also protected cells against another cholesterol-dependent cytolysin, streptolysin O, and protected lung epithelial cells and primary dermal fibroblasts against cytolysis. Our findings imply that treatment with bisphosphonates that inhibit squalene synthase might help protect tissues against pathogenic bacteria that secrete cholesterol-dependent cytolysins.

Adipokines as biomarkers of postpartum subclinical endometritis in dairy cows

Adipokines emerged as regulators of metabolism and inflammation in several scenarios. This study evaluated the relationship between adipokines (adiponectin, chemerin and visfatin) and cytological (subclinical) endometritis, by comparing healthy (without), transient (recovered by 45 days postpartum (DPP)) and persistent (until 45 DPP) endometritis cows (n = 49). Cows with persistent endometritis had higher adiponectin concentrations in plasma (at 21 DPP, P < 0.05 and at 45 DPP, P < 0.01) and in uterine fluid (at 45 DPP, P < 0.001), and higher chemerin concentrations in plasma (P < 0.05) and uterine fluid (P < 0.01) at 45 DPP than healthy cows. Cows with persistent endometritis had higher gene transcription in the cellular pellet of uterine fluid and protein expression in the endometrium of these adipokines and their receptors than healthy cows. Adiponectin plasma concentrations allowed to discriminate healthy from persistent endometritis cows, in 87% (21 DPP) and 98% (45 DPP) of cases, and adiponectin and chemerin uterine fluid concentrations at 45 DPP allowed for this discrimination in 100% of cases. Cows with concentrations above the cutoff were a minimum of 3.5 (plasma 21 DPP), 20.4 (plasma 45 DPP), and 33.3 (uterine fluid 45 DPP) times more at risk of evidencing persistent endometritis at 45 DPP than cows with concentrations below the cutoff. Overall, results indicate a relationship between adipokine signalling and the inflammatory status of the postpartum uterus of dairy cows, evidencing that adipokines represent suitable biomarkers of subclinical endometritis, able to predict the risk of persistence of inflammation.

Uterine infection alters the transcriptome of the bovine reproductive tract three months later

Infection of the postpartum uterus with pathogenic bacteria is associated with infertility months later in dairy cattle. However, it is unclear whether these bacterial infections lead to long-term changes in the reproductive tract that might help explain this infertility. Here we tested the hypothesis that infusion of pathogenic bacteria into the uterus leads to changes in the transcriptome of the reproductive tract 3 months later. We used virgin Holstein heifers to avoid potential confounding effects of periparturient problems, lactation, and negative energy balance. Animals were infused intrauterine with endometrial pathogenic bacteria Escherichia coli and Trueperella pyogenes (n = 4) and compared with control animals (n = 6). Three months after infusion, caruncular and intercaruncular endometrium, isthmus and ampulla of the oviduct, and granulosa cells from ovarian follicles >8 mm diameter were profiled by RNA sequencing. Bacterial infusion altered the transcriptome of all the tissues when compared with control. Most differentially expressed genes were tissue specific, with 109 differentially expressed genes unique to caruncular endometrium, 57 in intercaruncular endometrium, 65 in isthmus, 298 in ampulla, and 83 in granulosa cells. Surprisingly, despite infusing bacteria into the uterus, granulosa cells had more predicted upstream regulators of differentially expressed genes than all the other tissues combined. In conclusion, there were changes in the transcriptome of the endometrium, oviduct and even granulosa cells, 3 months after intrauterine infusion of pathogenic bacteria. These findings imply that long-term changes throughout the reproductive tract could contribute to infertility after bacterial infections of the uterus.

The effect of pegbovigrastim on early-lactation disease, production, and reproduction in dairy cows

The objective of this randomized, double-blind, controlled trial was to evaluate the effect of pegbovigrastim (pegylated recombinant bovine granulocyte colony-stimulating factor) on early-lactation disease, milk yield, and reproduction on commercial dairy farms. A total of 1,607 Holstein cows from 6 farms in Ontario and Québec, Canada, were randomly assigned to receive two 2.7-mL subcutaneous injections of either 15 mg of pegbovigrastim (n = 798; Imrestor, Elanco) or sterile physiological saline (placebo; n = 809). The first injection was administered by investigators 1 wk before expected calving, and the second by farm personnel within 24 h after calving, according to the product label. Producers inspected cows daily and using standardized disease definitions, recorded cases of retained placenta, metritis, displaced abomasum, and clinical mastitis until 63 d in milk. Progesterone concentration was measured in serum at wk 3, 5, 7, and 9 postpartum. Cows were examined for purulent vaginal discharge using the Metricheck (Simcro) device and endometritis using the cytobrush method at wk 5 postpartum. Milk production and reproduction data were obtained from farm management software and the national milk recording database. Disease and culling outcomes were assessed with logistic regression, milk production with linear regression, and time-to-event outcomes with proportional hazards regression. All analyses considered parity and pre-treatment body condition score and their interaction with treatment, and accounted for clustering of cows within farm. In a subset of 246 cows, the effect of treatment on metabolic markers (serum concentrations of glucose, β-hydroxybutyrate, nonesterified fatty acids, cholesterol, haptoglobin, albumin, and calcium) was assessed in wk 1 and 2 postpartum. Pegbovigrastim had no significant effects on the incidence of retained placenta, metritis, displaced abomasum, clinical or subclinical mastitis, purulent vaginal discharge, or endometritis. Treatment reduced the serum concentration of glucose, slightly reduced the concentration of albumin, and slightly increased concentrations of β-hydroxybutyrate and nonesterified fatty acids, with no effect on the other markers. There were no differences between treatments in culling risk, time to first insemination, pregnancy at first insemination, or time to pregnancy. Milk yield over the first 3 test days of lactation was 1.0 kg per day lower in the pegbovigrastim group, although a mechanism for that effect could not be explained through analysis of our data.

Invited review: The influence of immune activation on transition cow health and performance-A critical evaluation of traditional dogmas

The progression from gestation into lactation represents the transition period, and it is accompanied by marked physiological, metabolic, and inflammatory adjustments. The entire lactation and a cow's opportunity to have an additional lactation are heavily dependent on how successfully she adapts during the periparturient period. Additionally, a disproportionate amount of health care and culling occurs early following parturition. Thus, lactation maladaptation has been a heavily researched area of dairy science for more than 50 yr. It was traditionally thought that excessive adipose tissue mobilization in large part dictated transition period success. Further, the magnitude of hypocalcemia has also been assumed to partly control whether a cow effectively navigates the first few months of lactation. The canon became that adipose tissue released nonesterified fatty acids (NEFA) and the resulting hepatic-derived ketones coupled with hypocalcemia lead to immune suppression, which is responsible for transition disorders (e.g., mastitis, metritis, retained placenta, poor fertility). In other words, the dogma evolved that these metabolites and hypocalcemia were causal to transition cow problems and that large efforts should be enlisted to prevent increased NEFA, hyperketonemia, and subclinical hypocalcemia. However, despite intensive academic and industry focus, the periparturient period remains a large hurdle to animal welfare, farm profitability, and dairy sustainability. Thus, it stands to reason that there are alternative explanations to periparturient failures. Recently, it has become firmly established that immune activation and the ipso facto inflammatory response are a normal component of transition cow biology. The origin of immune activation likely stems from the mammary gland, tissue trauma during parturition, and the gastrointestinal tract. If inflammation becomes pathological, it reduces feed intake and causes hypocalcemia. Our tenet is that immune system utilization of glucose and its induction of hypophagia are responsible for the extensive increase in NEFA and ketones, and this explains why they (and the severity of hypocalcemia) are correlated with poor health, production, and reproduction outcomes. In this review, we argue that changes in circulating NEFA, ketones, and calcium are simply reflective of either (1) normal homeorhetic adjustments that healthy, high-producing cows use to prioritize milk synthesis or (2) the consequence of immune activation and its sequelae.

LPS Mediates Bovine Endometrial Epithelial Cell Pyroptosis Directly Through Both NLRP3 Classical and Non-Classical Inflammasome Pathways

As a highly inflammatory form of programmed cell death, pyroptosis is triggered by pro-inflammatory signals and associated with inflammation. It is characterized by cell swelling and large bubbles emerging from the plasma membrane, which release cytokines during inflammation. Compared with other types of cell death, pyroptosis has a distinct morphology and mechanism and involves special inflammasome cascade pathways. However, the inflammasome mechanism through which endometrial epithelial cell pyroptosis occurs in LPS-mediated inflammation remains unclear. We confirmed that there was an increased mRNA and protein expression of the IL-6, TNF-α, IL-1β, IL-18 cytokines, the inflammasome molecules NLRP3, CASPASE-1, CASPASE-4, and GSDMD in LPS-induced primary bovine endometrial epithelial cells (BEECs) in an in vitro established inflammatory model using ELISA, real-time PCR (RT-PCR), vector construction and transfection, and Western blotting. Scanning electron microscopy and lactate dehydrogenase (LDH) activity assays revealed induced cell membrane rupture, which is the main characteristic of pyroptosis. In conclusion, the cytolytic substrate GSDMD’s cleavage by caspase-1 or caspase-4 through the NLRP3 classical and non-classical inflammasome pathways, GSDMD N-terminus bind to the plasma membrane to form pores and release IL -18, IL-1β cause cell death during LPS induced BEECs inflammation.

Modulation of Bovine Endometrial Cell Receptors and Signaling Pathways as a Nanotherapeutic Exploration against Dairy Cow Postpartum Endometritis

Simple Summary

The provision of updated information on the molecular pathogenesis of bovine endometritis with host-pathogen interactions and the possibility of exploring the cellular sensors mechanism in a nanotechnology-based drug delivery system against persistent endometritis were reported in this review. The mechanism of Gram-negative bacteria and their ligands has been vividly explored, with the paucity of research detail on Gram-positive bacteria in bovine endometritis. The function of cell receptors, biomolecules proteins, and sensors were reportedly essential in transferring signals into cell signaling pathways to induce immuno-inflammatory responses by elevating pro-inflammatory cytokines. Therefore, understanding endometrial cellular components and signaling mechanisms across pathogenesis are essential for nanotherapeutic exploration against bovine endometritis. The nanotherapeutic discovery that could inhibit infectious signals at the various cell receptors and signal transduction levels, interfering with transcription factors activation and pro-inflammatory cytokines and gene expression, significantly halts endometritis.

Abstract

In order to control and prevent bovine endometritis, there is a need to understand the molecular pathogenesis of the infectious disease. Bovine endometrium is usually invaded by a massive mobilization of microorganisms, especially bacteria, during postpartum dairy cows. Several reports have implicated the Gram-negative bacteria in the pathogenesis of bovine endometritis, with information dearth on the potentials of Gram-positive bacteria and their endotoxins. The invasive bacteria and their ligands pass through cellular receptors such as TLRs, NLRs, and biomolecular proteins of cells activate the specific receptors, which spontaneously stimulates cellular signaling pathways like MAPK, NF-kB and sequentially triggers upregulation of pro-inflammatory cytokines. The cascade of inflammatory induction involves a dual signaling pathway; the transcription factor NF-κB is released from its inhibitory molecule and can bind to various inflammatory genes promoter. The MAPK pathways are concomitantly activated, leading to specific phosphorylation of the NF-κB. The provision of detailed information on the molecular pathomechanism of bovine endometritis with the interaction between host endometrial cells and invasive bacteria in this review would widen the gap of exploring the potential of receptors and signal transduction pathways in nanotechnology-based drug delivery system. The nanotherapeutic discovery of endometrial cell receptors, signal transduction pathway, and cell biomolecules inhibitors could be developed for strategic inhibition of infectious signals at the various cell receptors and signal transduction levels, interfering on transcription factors activation and pro-inflammatory cytokines and genes expression, which may significantly protect endometrium against postpartum microbial invasion.

Aucubin ameliorates the LPS-induced inflammatory response in bovine endometrial epithelial cells by inhibiting NF-κB and activating the Keap1/Nrf2 signalling pathway

Cows are susceptible to pathogenic bacterial infection after pregnancy, leading to inflammation of the endometrium. Aucubin (AU) has been proven to exhibit highly effective anti-inflammatory activity, but its ability to protect against endometritis in dairy cows remains unclear. Therefore, the goal of the present study was to evaluate the protective effect of AU on the LPS-induced inflammatory response of bovine endometrial epithelial cells (BEECs). After pre-treating BEECs with AU (10, 20 and 50 μM) for 6 hr, the cells were stimulated with LPS for 3 hr. Subsequently, BEECs apoptosis was analysed by flow cytometry, the expression of pro-inflammatory cytokine mRNA was detected by qRT-PCR, and changes in NF-κB and Keap1/Nrf2 signalling were analysed by western blotting and immunofluorescence analyses. The results showed that AU can reduce TNF-α, IL-1β, IL-6, COX-2 and iNOS mRNA expression in BEECs and reduce cell apoptosis. Furthermore, AU significantly reduced the level of NF-κB p65 and IκB phosphorylation and inhibited the nuclear translocation of NF-κB p65. AU also activated the Keap1/Nrf2 pathway, promoting the nuclear transfer of Nrf2 and increasing Keap1, Nrf2, HO-1 and NQO1 mRNA and protein levels. Taken together, these results indicate that AU ameliorates the LPS-induced inflammatory response by inhibiting NF-κB and activating the Keap1/Nrf2 signalling pathway, which has a protective effect on BEECs.

MicroRNA: Could It Play a Role in Bovine Endometritis?

Endometritis in dairy cows is a major economic problem worldwide; without advances in lifestyle management and drug treatment, it causes high morbidity and death. Micro ribonucleic acid (miRNAs) these days is seen as an important part of gene control networks. It is a class of small nucleotides 20-25, single-stranded RNA molecules. In endometritis, the inflammatory response caused by the gram-negative bacteria Escherichia coli (E. coli) alters the expression of miRNA which can regulate the innate immune system. This manuscript reviews (1) the interaction of miRNAs with the signaling of NF-κB and dysregulation of miRNAs and NF-κB activity in endometritis and (2) the activity of miR-let-7c, miR-148a, and miR-488 in NF-κB activation and their effect on endometritis. Cows with reduced immunity are more vulnerable to transition diseases, such as endometritis. During post-partum, cows undergo stress, metabolic disorders, hormonal imbalance, negative energy balance, and changes in diet. One of the many categories of regulatory molecules, which explain its natural function and pathological impact on NF-κB dysregulation, is important to inform the complexity of the immune system and to develop treatments for endometritis. It shows that miRNAs could have multiple applications in veterinary medicine. Nevertheless, a comprehensive study of is essential which should be aimed at exploring the role of microRNA at physiological level and its effect due to dysfunction and dysregulation.

Failure of clinical cure in dairy cows treated for metritis is associated with reduced productive and reproductive performance

Objectives were to assess reproductive and productive outcomes associated with failure of clinical cure in dairy cows diagnosed with metritis following antimicrobial therapy. This retrospective cohort study included data from 3 experiments performed in 5 dairies. Metritis was characterized by the presence of watery, fetid, reddish-brownish vaginal discharge within 21 DIM (study d 0). Cows not diagnosed with metritis (i.e., cows may have had other diseases postpartum; NoMT; n = 1,194) were paired based on lactation number and calving date. All cows with metritis received antimicrobial therapy (ampicillin or ceftiofur). Clinical cure was evaluated on d 10 based on vaginal discharge score, and cows were categorized as cured (MTC; n = 1,111) or not cured (MTnoC; n = 299). Purulent vaginal discharge (28 ± 3 or 32 ± 3 DIM), cytological endometritis (35 ± 3 or 39 ± 3 DIM), and estrous cyclicity (50 ± 3 and 64 ± 3, 36 ± 3 and 50 ± 3, or 37 ± 5 and 51 ± 5 DIM) were evaluated in subgroups of cows. Proportions of cows with purulent vaginal discharge and cytological endometritis were greatest for MTnoC (91.7 and 91.4%), intermediate for MTC (74.0 and 73.3%), and smallest for NoMT (38.1 and 36.4%). Proportion of cyclic cows was smaller for MTnoC compared with MTC and NoMT (62.0, 71.0, and 71.0%). Pregnancy per artificial insemination following first service was smaller for cows with metritis compared with their counterparts with no metritis (NoMT = 28.1, MTC = 26.1, MTnoC = 22.0%). Pregnancy loss tended to be greater for MTnoC compared with MTC (NoMT = 11.5, MTC = 11.1, MTnoC = 18.4%). Hazard of pregnancy by 300 DIM was smallest for MTnoC, intermediate for MTC, and greatest for NoMT. Death by 60 DIM (3.9, 1.1, and 0.6%) and removal from herd by 300 DIM (26.3, 17.4, and 15.4%) were greatest for MTnoC compared with MTC and NoMT, respectively. Milk production among multiparous cows was smaller for MTnoC compared with MTC and NoMT in the first 10 mo postpartum, whereas MTC produced less milk compared with NoMT only during the first 2 mo postpartum (NoMT = 42.0 ± 0.22, MTC = 40.6 ± 0.28, MTnoC = 37.7 ± 0.54 kg/d). Failure of clinical cure was not associated with milk yield in primiparous cows (NoMT = 35.2 ± 0.31, MTC = 33.9 ± 0.31, MTnoC = 35.0 ± 0.52 kg/d). Cows diagnosed with metritis that do not undergo clinical cure by 10 d of onset of antimicrobial therapy have impaired reproductive performance, reduced milk production, and increased risk of leaving the herd.

Chlorogenic acid ameliorates mice clinical endometritis by activating Keap1/Nrf2 and inhibiting NFκB signalling pathway

OBJECTIVES

Clinical endometritis is a common reproductive disorder in mammals that seriously endangers animal health and causes economic losses worldwide. This study aims to use lipopolysaccharide and Trueperella pyogenes exotoxin as modelling reagents (LC) to perfuse the mouse uterus in order to establish a model of clinical endometritis and to investigate the anti-inflammatory and antioxidant effects of chlorogenic acid (CGA).

METHODS

In this study, five LC uterine perfusions were selected to model clinical endometritis. The anti-inflammatory and antioxidant effects of CGA were clarified. Through HE staining, proinflammatory cytokines, blood testing, NFκB and Keap1/Nrf2 signalling pathways and other index changes to explore the protection mechanism of CGA.

KEY FINDINGS

After CGA treatment, the appearance, inflammatory damage and blood indicators of the mouse uterus returned to normal. Simultaneously, CGA could inhibit the activation of NFκB and reduce the release of inflammatory cytokines; CGA could also activate Keap1/Nrf2, promote the dissociation of Keap1 and Nrf2 and significantly increase the expression of the downstream genes HO-1 and NQO1.

CONCLUSIONS

The above results together explain that five LC uterine perfusions can be used to establish a mouse model of clinical endometritis. CGA can treat clinical endometritis by activating Keap1/Nrf2 and inhibiting the NFκB signalling pathway.

Tanshinone IIA exhibits anti-inflammatory and antioxidative effects in LPS-stimulated bovine endometrial epithelial cells by activating the Nrf2 signaling pathway

Endometritis is a major disease in productive bovines, and is also caused by conditional pathogens after delivery. The integrity and activity of bovine endometrial epithelial cells (bEECs) determine the development of endometritis. Tanshinone IIA, a compound purified from Salvia miltiorrhiza bunge, has been reported to have anti-inflammatory effects. The aim of this study was to investigate the anti-inflammatory effects of tanshinone IIA in the LPS-induced inflammatory response of bEECs. The results showed that tanshinone IIA inhibited the mRNA expression levels of COX-2 and iNOS, and reduced the expression levels of IL-1β, TNF-α, IL-6 and IL-8 induced by LPS. In addition, we found that tanshinone IIA inhibited the level of MDA, but increased the activities of CAT and SOD. To evaluate the anti-inflammatory mechanism of tanshinone IIA, we examined the activation of Nrf2. The results showed that the Nrf2 signaling pathway was significantly activated by tanshinone IIA. In conclusion, these results showed that tanshinone IIA exhibited anti-inflammatory and antioxidative effects by activating the Nrf2 signaling pathway.

Risk factors associated with testing positive for tuberculosis in high-yielding Holstein cows

Tuberculosis remains a significant infectious disease of farm animals and humans worldwide. The objective of this study was to assess various risk factors associated with testing positive for bovine tuberculosis (bTB) in high-yielding Holstein cows in an intensive dry-lot dairy operation. In a retrospective observational study, 9312 records from Holstein cows from a large dairy herd in northern Mexico were used. The incidence rate of lactating cows reactor to bTB was 7.3 cases/100 cow years (95% CI = 6.7-7.9%). Multiple logistic regression models indicated that cows with total milk yield during the first lactation >10,200 kg were 1.3 times (95% confidence intervals (CI) for odds ratio (OR) = 1.2-1.6) more likely to be detected as bTB reactors than cows with total milk yield <10,200 kg (8.2 vs. 6.4%; P < 0.01). The risk of being reactor to bTB increased with x̅ total milk yield/lactation >11,500 kg (OR=2.7, 95% CI = 2.3-3.3; 10.4 vs. 4.2%) compared with cows with x̅ total milk yield/lactation <11,500 kg. Cows with >10,200 kg 305-day milk yield in the last lactation was associated (P < 0.01) with 1.3 times higher odds (95% CI for OR = 1.1-1.5) of being classed as reactors than cows with <10,200 kg. Cows with peak milk yield >48 kg were 1.9 times (95% CI for OR = 1.6-2.2) more likely to be reactor to bTB than cows with peak milk yield <48 kg (9.2 vs. 5.1%; P < 0.01). Cows with either puerperal metritis (OR = 0.07, 95% CI = 0.5-0.9) or carrying twins (OR = 0.05, 95% CI = 0.01-0.19) had a protective role for being reactor to bTB. This study showed that increased milk production was associated with a higher risk of becoming positive to tuberculin skin test in high-yielding Holstein cows.

Pre- and Post-partum Concentrations of Interleukin 1α, Interleukin 8, and α1-Acid Glycoprotein in Vaginal Fornix and Endometrium of Dairy Cows With Clinical Cervicitis

Innate immunity is the principal sensor responsible of the local immune response to control mucosal bacterial contamination of the reproductive tract after parturition, triggering a pro-inflammatory process in the mucosa of the uterus, the vaginal and the cervix. However, knowledge about the inflammation process and outcome of the cervix in dairy cows is scarce even though it plays an important anatomic and functional role between the vagina and the uterus. The objective of the present study was to describe the cellular and humoral local innate immune response during clinical cervicitis (CC) in the uterus and vaginal fornix in pre- and post-partum periods of dairy cows. A retrospective descriptive study was performed involving 26 animals, characterized as clinical cervicitis cows (n = 19) and healthy cows (n = 7). Blood and mucus of the different compartments of the genital tract were sampled and records of the cows' genital exam were performed four times: −1 w (day −7 ± 2, prepartum), +1 w (day +7 ± 4), +3 w (day +21 ± 4) and +5 w (day +35 ± 4) postpartum. Clinical cervicitis was defined as cows exhibiting a cervix grade−2 and healthy cows were defined as a cow clinically normal with a grade-0 cervix at time +5 w. Blood white cell count, vaginal fornix and endometrial neutrophils percentage, and the concentrations of interleukin 1α (IL1), interleukin 8 (IL8), and α1-acid glycoprotein (AGP) in mucus were determined. The results showed that 23% of the cows were categorized as CC at time +5 w. Cases of CC with purulent vaginal discharge or subclinical endometritis shown the highest cytokine production. At +3 w, IL1, IL8, and AGP concentrations in the uterus and the fornix were significantly higher in CC than healthy cows (CH). In conclusion, the 3-week postpartum is a critical point to evaluate cytokines and acute phase proteins; where IL1 and IL8 variation kept a direct relation with neutrophils numbers and function. The presence of AGP in the endometrium infer a homeostatic proinflammatory protective balance effect, modulating the local uterine innate immune response during peripartum.

Prediction of Calving to Conception Interval Length Using Algorithmic Analysis of Endometrial mRNA Expression in Bovine

Simple Summary

Our study aimed to develop the unsupervised clustering model based solely on selected markers to investigate the association between calving conception interval length, subclinical endometritis, and endometrial gene expression. An algorithmic analysis of endometrial gene expression showed a higher predictive ability to identify cows exhibiting excellent fertility than previously used methods, highlighting the correlation between INHBA/INHA and calving–conception interval length.

Abstract

After parturition, the uterus undergoes significant reconstruction, allows the endometrium to create an environment for subsequent embryo development. Here, we used an unsupervised algorithmic approach to select characteristic endometrial mRNA expression patterns of proposed markers and investigate each marker’s role as an individual indicator of reproductive success. Clinically healthy cows at a sixth week postpartum were examined, the percentage of neutrophils (PMNs%) in the cytological smear was calculated, and an endometrial biopsy was taken for qPCR. Based on pregnancy examination, cows were divided into three groups: Pregnant before 100 days postpartum (P100, n = 11), pregnant between 100–200-day (P200, n = 14), and culled (C, n = 10). Animals were also classified based on two PMNs% thresholds > 5% PMNs and > 10% PMNs. The expression of IL1B, IL6, CXCL8, and IL17A was higher in >10%PMNs. The expression of PTGS1 was higher in the P200 compared to P100. Upregulation of inhibin A subunit (INHA) and downregulation of inhibin β A subunit (INHBA) were observed in the P100. INHBA/INHA ratio was the most accurate linear predictor of the calving-to-conception interval. The application of the k-means algorithm allowed the identification of five unique expression patterns. The sensitivity and specificity of predicting allocation to P100 were 81% and 79%. We also documented the low efficiency of genes associated with subclinical endometritis and PMNs% in determining reproductive capability. These results suggested the presence of distinctive expression patterns in 6 weeks postpartum, correlated with cows’ reproductive capacity. Furthermore, we proposed the INHBA/INHA ratio as an indicator of calving-to-conception interval length.

Molecular characterization of extended-spectrum β-lactamase-producing Escherichia coli isolated from postpartum uterine infection in dairy cattle in India

BACKGROUND AND AIM

Selection and dissemination of plasmid-encoded extended-spectrum β-lactamase (ESBL) among Enterobacteriaceae confers resistance to beta-lactam antibiotics. The purpose of this study was to determine the prevalence and molecular characteristics of ESBL-producing organisms isolated from dairy cattle with a uterine infection.

MATERIALS AND METHODS

Bacterial isolates (n=62) were characterized by biochemical test for genus and species determination. Antimicrobial susceptibility tests were performed by Kirby-Bauer disk diffusion method using panel of antibiotics for initial screening of ESBL organism. Phenotypic confirmation of ESBL-suspected strains was done by combination disk method and double-disk method. Multiplex polymerase chain reaction (PCR) was carried out for phylogrouping of Escherichia coli isolates as well as for genotyping ESBL genes. Enterobacterial repetitive intergenic consensus-PCR method was used for genotypic characterization of isolates.

RESULTS

Antibiotic susceptibility profile of E. coli (n=40) isolates showed high rates of resistance for ampicillin (95.0%), cefpodoxime (97.5%), cefotaxime (87.5%), and ceftriaxone (70%). However, low rates of resistance were observed for cefoxitin (25%), amoxicillin/clavulanic acid (20%), ceftazidime (17.5%), gentamicin (10%), and ertapenem (7.5%). A total of 39/40 E. coli isolates were confirmed as ESBL with Epsilometer test as well as the genotypic method and 28 (70%) of them were multidrug-resistant. Genotype blaCTX-M was observed as a predominant beta-lactamase type with the preponderance of CTX-M Group 1. The following combinations were observed: blaTEM + blaCTX-M in 15 (36.2%) isolates, blaTEM /blaSHV in 8 (5.2%) isolates, and blaCTX-M /blaSHV in 6 (5.2%) isolates. The phylogenetic grouping of E. coli strains revealed the highest prevalence for B1 (22.0%) followed by A (20%).

CONCLUSION

This report shows a high frequency of ESBL E. coli from cattle with postpartum uterine infections. These isolates showed reduced susceptibility to common antibiotics used for the treatment of uterine infections greater affecting the therapeutic outcome.

The Role of Exosomal Epigenetic Modifiers in Cell Communication and Fertility of Dairy Cows

Abnormal uterine function affects conception rate and embryo development, thereby leading to poor fertility and reproduction failure. Exosomes are a nanosized subclass of extracellular vesicles (EV) that have important functions as intercellular communicators. They contain and carry transferable bioactive substances including micro RNA (miRNA) for target cells. Elements of the cargo can provide epigenetic modifications of the recipient cells and may have crucial roles in mechanisms of reproduction. The dairy industry accounts for a substantial portion of the economy of many agricultural countries. Exosomes can enhance the expression of inflammatory mediators in the endometrium, which contribute to various inflammatory diseases in transition dairy cows. This results in reduced fertility which leads to reduced milk production and increased cow maintenance costs. Thus, gaining a clear knowledge of exosomal epigenetic modifiers is critical to improving the breeding success and profitability of dairy farms. This review provides a brief overview of how exosomal miRNA contributes to inflammatory diseases and hence to poor fertility, particularly in dairy cows.

Curcumin inhibits lipopolysaccharide and lipoteichoic acid-induced expression of proinflammatory cytokines and production of PGE2 in the primary bubaline endometrial stromal cells

Infection of the uterus with Gram-positive Trueperella pyogenes and Gram-negative Escherichia coli is a common cause of postpartum endometritis in the cattle and buffalo and the condition is treated with antimicrobial drugs. The presence of drug residues in the milk and development of resistant bacteria necessitate the evaluation of alternate therapies for endometritis. Accordingly, we tested the immunomodulatory effect of curcumin in the bubaline endometrial stromal cells after treatment with the lipoteichoic acid (LTA) of Gram-positive Staphylococcus aureus and lipopolysaccharide (LPS) of Gram-negative E. coli that activate toll-like receptors (TLR-2 and TLR-4, respectively). Confluent primary culture of endometrial stromal cells was treated with LTA (1 µg/mL) and/or LPS (0.1 µg/mL), in the presence or absence of curcumin (30 µM for 24 h). PGE₂ was assayed in the supernatant and the relative expression of proinflammatory cytokines (PICs) (IL1B, IL6, IL8 and TNFA) transcripts were quantified using real-time PCR. LTA was not effective in stimulating PGE₂ production or upregulating the PIC expression except IL8. LTA+LPS increased PGE₂ production and upregulated IL6 and IL8 genes. Curcumin inhibited the basal and LTA+LPS induced production of PGE₂ and upregulation of PIC production. It was apparent that LPS, but not LTA, is a potent stimulator of PGE₂ from the bubaline endometrial stromal cells. Curcumin downregulated the expression of LPS and/or LTA induced PICs and PGE₂ and may be an alternate to antimicrobial drugs for the therapeutic management of endometritis.

Protective Effect of Hydroxytyrosol on LPS-Induced Inflammation and Oxidative Stress in Bovine Endometrial Epithelial Cell Line

Bovine endometritis is a serious pathogen-induced infectious disease that affects the physiological processes of estrus, pregnancy and the postpartum condition. The inflamed endometrium responds by activating an inflammatory intracellular signaling cascade that leads to increased expression of proinflammatory cytokines and reactive oxygen species (ROS). Oxidative stress is closely related to several pathological conditions in perinatal dairy cows and play a key role in tissue damage. Hydroxytyrosol (HT), a natural phenolic alcohol with a strong antioxidant activity, displayed a wide range of biological effect. The aim of this study was to evaluate the protective effects of HT in an in vitro model of lipopolysaccharide (LPS)-induced inflammation in bovine uterine endometrial cells. Our results showed that HT had a significant protective effect in LPS-induced inflammation and oxidative stress. HT was also able to increase the capacity of endogenous antioxidant systems through the up-regulation of the NRF2 pathway. Furthermore, HT restored the tight junction protein expressions. In conclusion, our results showed the protective effects of HT in LPS-stimulated BEND cells. Therefore, the results of this study suggest an important protective role of HT in the treatment and prevention of uterine pathologies in dairy cows.

Serum biochemical profile in buffalo endometritis and impact of treatment with PGF2α and intrauterine gentamicin infusion on postpartum reproductive performance

Improving reproductive performance of repeat breeder buffalo cows due to clinical endometritis is crucial in overcoming infertility problems in buffalo cows. The aim of the present study was to use PGF2α and/or gentamicin 10% for treatment of endometritis and to determine biochemical parameters in serum that could be used to diagnose endometritis in buffalo cows. A total of 64 anestrous buffalo cows were assigned into one of five treatment groups: group one (n = 9) buffalo cows were physiological normal cows and served as a control group; group 2 buffalo cows had endometritis, but were not treated (n = 10); group 3 buffalo cows had endometritis and were treated with intrauterine delivery of 100 ml of a 10% gentamicin sulfate solution in three times within 1 week (n = 15); group 4 buffalo cows received two I.M. doses of PGF2α (2 ml Estrumate IM) at the time of corpus luteum dominance (n = 15) (treatment 4 does not make sense as you stated that the cows were in anestrus) on the ovary; group 5 buffalo cows received two IM doses of PGF2α at an 11 day interval and the 10% gentamicin solution as described for group 3. Serum samples were collected from control, pre-treated, and post-treated buffalo cows with endometritis to evaluate the diagnostic biochemical parameters. The days to first estrus (DFE), number of services per conception (S/C), days open (DO), and pregnancy rate (Preg) were the measures for determining reproductive performance for the buffalo cows. The buffalo cows treated by gentamicin and PGF2 exhibited their first estrus earlier than cows in the other four groups of cows. The number of days open for control cows was greater (P < 0.05) than for the other groups and the control cows, as were the number of services per conception (P < 0.05) and pregnancy rate (30%: P < 0.05). The receiver operating characteristic (ROC) curve was used to identify biochemical parameters in serum to predict endometritis. Creatine kinase (CK), aspartate aminotransferase (AST), and concentrations of total bilirubin and immunoglobulins in serum were greater (P < 0.05), while serum albumin values were lower (P < 0.05) in serum of buffalo cows with endometritis. From the ROC analyses, CK was the most predictable biomarker for endometritis with an area under the curve of 0.889, sensitivity of 80%, and specificity of 100% (P < 0.001). In conclusion, the use of gentamicin and PGF2 for treatment of endometritis improves the reproductive performance of buffalo cows, and concentrations of CK serve as an aid for diagnosing endometritis.Graphical abstract.

Leukocyte populations in peripheral blood of dromedary camels with clinical endometritis

Endometritis represents the main cause of reproductive failure in dromedary camels. In dromedary camels, associations between endometritis-causing pathogen-species, disease severity, and systemic changes in the immune system have not been evaluated. In the current study, there was use of flow cytometry and immunofluorescence of membrane proteins for the evaluation of leukocyte subsets and the cellular phenotype in blood of camels with clinical endometritis and evaluations of associations with disease severity and endometritis-causing pathogens. Animals with endometritis had markedly larger numbers of total leukocytes and neutrophils. Although total lymphocyte and monocyte counts did not differ between camels with and without clinical endometritis, there were lesser numbers of total and effector CD4-positive T cells in camels with endometritis. Among monocytes, number of camel inflammatory monocytes (Mo-II) was markedly greater, whereas Mo-III numbers were less in the blood of camels with clinical endometritis. Number of inflammatory monocytes was also indicative of endometritis severity grade. Among camels with clinical endometritis, E. coli- and S. aureus-infected animals had similar endometritis grades and comparable phenotype and composition patterns of leukocytes. Neutrophils and monocytes of camels with clinical endometritis had fewer cell adhesion molecules (i.e., CD11a and CD18). Collectively, the results from the current study allowed for identification of associations between endometritis severity grade and larger numbers of inflammatory monocytes. The results also indicate there is no association between endometritis pathogen-species and changes in phenotype or composition of blood leukocytes.

Association of bovine uterine involution disturbances with serum neuropeptide concentrations

Background and Aim

Puerperal diseases influence fertility and should be diagnosed as soon as possible. This study aimed to evaluate the applicability of serum concentrations of substance P (SP), vasoactive intestinal polypeptide (VIP), and interleukin (IL)1β in the early diagnosis of uterine involution disturbances.

Materials and Methods

Blood serum samples of 86 dairy cows from six different farms were harvested within the first 20 days after calving from cows with uterine involution disturbances and healthy controls, respectively. Serum concentrations for SP, VIP, and IL-1β were determined using commercially available ELISA test kits. Statistical analyses included timely changes in blood serum levels and group comparisons of healthy cows and cows with uterine disease.

Results

SP concentrations increased significantly within 20 days after calving (p<0.04) with no significant difference observed between the groups. Moreover, no significant differences were found between VIP and log IL-1β.

Conclusion

Results showed that none of the examined serum parameters seems suitable as indicator of uterine involution disorders. Due to the timely changes in serum concentrations of SP after calving, a correlation to diseases might not be precluded. Further research is needed as regards the establishment of normative values concerning this parameter.

Biofilm forming potentiality of Escherichia coli isolated from bovine endometritis and their antibiotic resistance profiles

OBJECTIVE

The objectives of this study were to determine the biofilm-forming capability and antimicrobial susceptibility of Escherichia coli recovered from bovine endometritis samples.

MATERIALS AND METHODS

A total of 120 uterine specimens were collected from cows suffering from endometritis for bacteriological examination. Antimicrobial susceptibility testing was carried out for all isolated E. coli by using the disc diffusion method. The isolates were phenotypically studied for biofilm-forming ability by cultivation on yeast extract -casamino acids Congo red agar (CRA). Some randomly selected isolates were chosen for the molecular identification of some virulence and resistance genes.

RESULTS

A total of 58(48.3%) E. coli isolates could be isolated from the 120 samples. Antimicrobial susceptibility testing exhibited that 91.4%, 79.3%, 79.3%, 74.1%, and 58.6% of the isolates were sensitive to gentamicin, amoxicillin-clavulanic acid, ciprofloxacin, cephalexin, and sulfamethoxazole- trimethoprim, respectively. On the other hand, 91.4% and 70.7% isolates were resistant to cefotaxime and doxycycline, respectively. Cultivation on CRA revealed that 46.6% of isolates were biofilm producers. The molecular detection of resistance and virulence genes declared that all isolates harbored bla TEM, sul1, tetA, qnrS, bla CTX-M , and fimH with a percentage of 100%, papC (40%), and hlyA (10%). FimH was the most prevalent biofilm-associated gene.

CONCLUSION

The present study highlights the high prevalence of multi-drug- resistant E. coli associated with bovine endometritis. The detection of the fimH gene is circumstantial evidenced that this gene has a crucial role in biofilm formation in intrauterine pathogenic E. coli.

[Bovine uterine diseases: Aspects of microbiology, molecular biology, and immunology]

Postpartum uterine diseases, such as puerperal metritis and clinical endometritis may affect over 40 % of cows in dairy farms. Regardless of their severity, these diseases are one of the main reasons for impaired fertility, causing declines in dairy cow productivity and hence, resulting in economic losses. Although uterine diseases have been the topic of scientific discussion for many years, until now it was not possible to agree on uniform definitions for the different kinds of manifestation. By including technical innovations and testing procedures, enormous scientific progress and a deeper knowledge of the physiology as well as the pathologic mechanisms have been achieved. Bovine metritis and endometritis may be regarded as multifactorial diseases caused by a combination of microbial infection, the dysregulation of the immune system, and additional risk factors. These interactions have been analyzed on microbial and molecular biological levels as well as by the use of bioinformatics and molecular genetics. As a result, new species of bacteria and inflammatory mediators possibly contributing to the development of uterine diseases have recently been described. Additionally, metabolic and genetic risk factors and their roles in leading to fertility impairment have been evaluated. In conclusion, it was possible to identify new approaches for possible therapeutic and preventive methods, a subset of which may already be implemented into daily practical routine. This article provides an overview of recent scientific results concerning bovine metritis and endometritis with a focus on microbial, microbiological and immunological studies.

Recent advances and future directions for uterine diseases diagnosis, pathogenesis, and management in dairy cows

Researchers, veterinarians, and farmers' pursuit of a consistent diagnosis, treatment, and prevention of uterine diseases remains challenging. The diagnosis and treatment of metritis is inconsistent, a concerning situation when considered the global threat of antimicrobial resistance dissemination. Endometritis is an insidious disease absent on routine health programs in many dairy farms and from pharmaceutical therapeutics arsenal in places like the US market. Conversely, a multitude of studies advanced the understanding of how uterine diseases compromise oocyte, follicle, and embryo development, and the uterine environment having long-lasting effects on fertility. The field of uterine disease microbiome also experienced tremendous progress and created opportunities for the development of novel preventives to improve the management of uterine diseases. Activity monitors, biomarkers, genomic selection, and machine learning predictive models are other innovative developments that have been explored in recent years to help mitigate the negative impacts of uterine diseases. Albeit novel tools such as vaccines for metritis, immune modulators, probiotics, genomic selection, and selective antimicrobial therapy are promising, further research is warranted to implement these technologies in a systematic and cost-effective manner.