Insights into bovine endometritis with special reference to phytotherapy

Bovine reproductive immunoinfertility: pathogenesis and immunotherapy

Infertility is one of the primary factors for cattle reproduction in the present scenario. Reproduction-related immunoinfertility mainly involves immunization against the antigens related to reproductive hormones (LHRH, GnRH, Gonadal steroids, PGF2α and oxytocin), spermatozoa, seminal plasma and ovum. Anovulation, delayed ovulation, sperm immobilization, failure of fertilization, prolonged uterine involution, extended calving interval, prolonged post-partum estrus and reduced conception rate could be a result of immunoinfertility that occur due to the blockage of receptor site by antibodies formed against hormones, sperm and ovum. Immunoinfertility can be treated in the animal by giving sexual rest to females, by using various reproductive technologies such as in-vitro fertilization, gamete intra fallopian tube transfer, and intracytoplasmic sperm injection, sperm washing and by treating the animals with immunomodulators such as LPS, Oyster glycogen, etc. This review summarizes the different causes of bovine reproductive immunoinfertility and amelioration strategies to overcome it.

Evaluation of blood serum iron concentration as an alternative biomarker for inflammation in dairy cows

This study aimed to clarify the relationship between acute phase protein (APP) concentrations and serum Fe concentrations to determine whether serum iron (Fe) can be clinically applied as a substitute for APPs in cows. One hundred five Holstein-Friesian breed lactating dairy cows were enrolled in this study. Cows with inflammatory diseases were 16 subclinical, and 15 severe mastitis cows, in addition to 15 mild and 16 severe sole ulcer cows. The plasma haptoglobin (HPT), alpha-1 acid glycoprotein (AGP), SAA, serum Fe levels, and other biochemical parameters in the cows were measured. The two-sample t-tests and multiple logistic regression analysis were used to compare the control and inflammatory disease groups. ROC analysis was used to evaluate the ability to diagnose inflammation disease. From the results, the proposed diagnostic cutoff value for plasma SAA and serum Fe concentrations to identify dairy cows with inflammatory diseases based on analyses of ROC curves were set at > 3.65 mg/l and < 120.50 µg/dl, respectively. Therefore, instead of using expensive inflammatory markers to evaluate the inflammatory state at the first treatment day for inflammatory diseases in cow, it shows the useful for screening with serum Fe concentration that can be measured easily and inexpensively as alternative inflammatory biomarkers.

Assessing the efficacy of probiotics in augmenting bovine reproductive health: an integrated in vitro, in silico, and in vivo study

The aim of this study was to isolate and characterize bovine-vaginal probiotics genotypically and phenotypically using in silico and evaluate their in vivo performance in buffaloes with endometritis. For the in vitro isolation and characterization, vaginal swabs were collected from 34 cows and 17 buffaloes, and 709 primary bacterial isolates with probiotic activity were obtained using MRS agar media. Two isolates Lactiplantibacillus plantarum KUGBRC (LPKUGBRC) and Pediococcus pentosaceus GBRCKU (PPGBRCKU) demonstrated optimum in vitro probiotic activities as compared to Lacticaseibacillus rhamnosus GG including, acid production, secretion of fatty acids and exopolysaccharide, cell surface hydrophobicity, self-aggregating and co-aggregating capacity with pathogens, anti-microbial activity and bacteriocin-like compounds against pathogens Escherichia coli and Staphylococcus aureus in cell-free supernatant and absence of hemolytic activity. Their phenotypic capacity was confirmed by analyzing the whole genome sequencing data and identifying genes and pathways associated with probiotic properties. These probiotic isolates have shown no virulence genes were discovered in their genomic study. In vivo study of 92 buffaloes suffering from clinical endometritis with purulent cervico-vaginal mucus (CVM) were randomly allocated 40 × 10⁸ CFU/ml LPKUGBRC and PPGBRCKU and 40 ml Normal saline. The LPKUGBRC reduced the duration between administration of probiotic to induction of healthy estrus significantly. However, no effect was observed on pregnancy rate. These results suggest that LPKUGBRC and PPGBRCKU probiotic bacteria demonstrate probiotic efficiency and adaptability. Further sourced from the same niche as the targeted infection, they offer a distinct advantage in targeting the specific microbial population associated with endometritis. The findings of this study highlight the potential of LPKUGBRC and PPGBRCKU probiotics in treating endometritis and suggest further exploration of their clinical applications.

Enhanced expression of miR-26a ameliorates lipopolysaccharide-induced endometritis by targeting MAP3K8 to inactivate MAPK signaling pathway

Endometritis is a severe postpartum inflammatory disease that puts cows' reproductive health at risk and causes the dairy industry to suffer significant financial losses. The present study aimed to investigate the regulatory role of miR‑26a in LPS‑induced bovine endometrial epithelial cells (bEECs) and the implication for endometritis. Here, we found inflammatory cell infiltration and destruction of endometrial structure in cow uterus, and dramatic increase in myeloperoxidase (MPO) activity and upregulation of pro-inflammatory cytokines (IL-1β, TNF-α, and IL-6) in endometritis. Meanwhile, miR-26a was down-regulated, but MAP3K8 was increased in the uterine tissue of endometritis. Similarly, the expression of miR-26a was significantly decreased in LPS-stimulated bEECs, while MAP3K8 was risen. In addition, we further verified that MAP3K8 was a target of miR-26a by dual-luciferase reporter assay. Under LPS stress, over-expressing miR-26a markedly decreased MAP3K8 expression levels, along with the reduced expression of inflammatory factors, such as IL-1β, TNF-α and IL-6, whereas this effect was countered by the inhibition of miR-26a. Furthermore, we demonstrated that miR-26a overexpression prevented the MAPK pathway from being activated by targeting MAP3K8. Then we carried out experiments in LPS-stimulated mice uterus to expound that MAP3K8 was essential in endometritis development, which further confirmed the reliability of the above results. In conclusion, overexpression of miR-26a effectively inhibited the expression of MAP3K8 in LPS-induced bEECs and thereby partially suppressed the activation of MAPK signaling pathway. miR-26a and MAP3K8 may be a promising biomarker and therapeutic target for dairy cow endometritis.

In-Depth Analysis of an Obligate Anaerobe Paraclostridium bifermentans Isolated from Uterus of Bubalus bubalis

Simple Summary

Non-specific uterine infections in bovine (uterine line inflammation) are a significant issue for the dairy industry. These infections are responsible for significant financial losses all over the world. Paraclostridium bifermentans is an obligate anaerobe, gram-positive rod-shaped bacteria belonging to the Clostridia class and the Peptostreptococcaceae family produces endospores. This bacterium has the ability to infiltrate bovine uterine endometrial epithelial cells and cause infection in the endometrium epithelial cells. Our study found that an examination of a buffalo uterus with yellowish purulent discharge reported the presence of pathogenic bacteria Paraclostridium bifermentans, where its genomic characterization, substrate utilization, and antibiotic susceptibility potentiality was studied. This discovery indicates the presence of virulence genes as well as pathogenic features. This is the first report of P. bifermentans from the bovine uterus environment.

Abstract

Chronic non-specific contamination of the reproductive tract in animals is a major issue during early postpartum, natural coitus, or artificial insemination. Uterine infection is one of the major concerns reducing fertility, production loss, and early culling of the animals. Therefore, the aim of this study was to identify any novel bacterium if present in the uterine environment of Bubalus bubalis causing infections. A strictly anaerobic bacterial strain designated as Paraclostridium bifermentans GBRC was isolated and characterized. Bacterium was found to be Gram positive moderate rod with motility. The optimum growth was observed at 40 ± 2 °C. The pathogenic characteristics of the GBRC strain, such as hemolysis, gelatin hydrolysis, and the production of volatile sulfur compounds, were similar to those seen in the epithelial layer invading pathogenic strains. Assembled genome size was 3.6 MB, with 78 contigs, and a G + C content of 28.10%. Furthermore, the whole genome sequence analysis confirmed the presence of genes encoding virulence factors and provided genomic insights on adaptation of the strain in the uterine environment. Based on the phenotypic and genetic differences with phylogenetic relatives, strain GBRC is proposed to represent a first reported species of the genus Paraclostridium with potential pathogenic character, from the buffalo uterine environment. This study analysis of the GBRC strain serves as a key reference point for the investigation of potential pathogenic strains that may cause endometritis and metritis in bovine.

miR-424-5p overexpression inhibits LPS-stimulated inflammatory response in bovine endometrial epithelial cells by targeting IRAK2

Endometritis is inflammation of endometrium due to various factors and is a common cause of infertility. Several remedies used for endometritis like antibiotics, hormones, and herbs. Studies confirm that microRNAs play a significant role in various inflammatory diseases. However, the role of miR-424-5p in endometritis is not clear. In our study, histopathology, real-time quantitative polymerase chain reaction, Western blot analysis, immunofluorescence, ELISA, and dual-luciferase reporter assay were used to elucidate the effect of miR-424-5p in lipopolysaccharide (LPS)-primed inflammatory response in bovine endometrial epithelial cells (BEECs) and clarify the potential mechanism. Our results revealed that miR-424-5p mimics noticeably decrease the production of proinflammatory cytokines (IL-1β, IL-6, and TNF-α), while miR-424-5p inhibitors have inverse effects in BEECs. Moreover, overexpression of miR-424-5p on BEECs cells also suppressed NF-κB p65 activation. Afterwards, we verified that miR-424-5p inhibited Interleukin 1 Receptor Associated Kinase 2 (IRAK2) expression by binding to the 3'-UTR of IRAK2 mRNA. Further, co-transfection of miR-424-5p inhibitors and siRNA-IRAK2 revealed that negative regulation of miR-424-5p on LPS-induced inflammatory response in BEECs was mediated by IRAK2.Mutually, miR-424-5p pharmacologic stabilization represents an entirely unique medical aid for cow endometritis and other inflammation-related diseases.

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.

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.

Gut microbiota mediate the protective effects on endometritis induced by Staphylococcus aureus in mice

Endometritis, the inflammation of the endometrial lining caused by bacterial pathogens, is associated with reproductive failure. Recent studies have shown that gut microbiota play an important role in infectious diseases. However, the roles of the gut microbiota in endometritis remain unclear. Here, we assessed the effects and mechanisms of the gut microbiota during endometritis induced by Staphylococcus aureus (S. aureus). A mouse gut microbiota-dysbiosis model was established by a mixture of antibiotics (Abx) and subsequently, a model of endometritis was established by the uterine perfusion of S. aureus. Fecal microbiota transplantation (FMT) was performed to evaluate the relationship between gut microbiota and endometritis. The results showed that the mice with gut microbiota-dysbiosis developed uterine inflammation, while this inflammatory response of the uterus was alleviated in mice with FMT to gut microbiota-dysbiosis. In addition, S. aureus-induced endometritis was greater in severity in the mice with gut dysbiosis as compared to the untreated mice. Moreover, these effects were reversed in mice with FMT to the gut microbiota-dysbiosis. GC-MS analysis demonstrated that the levels of short-chain fatty acids (SCFAs) in the feces of mice with gut microbiota-dysbiosis significantly decreased and pretreatment with sodium butyrate or sodium propionate increased the concentrations of butyrate or propionate in both the circulation and uterine tissues, thereby reducing the severity of endometritis induced by S. aureus. In addition, the increased pathogen load in the uteri of the mice with gut microbiota-dysbiosis was associated with a reduction in the phagocytic ability and responsiveness of neutrophils. In conclusion, the gut microbiota offer a protective effect against S. aureus-induced endometritis by regulating the levels of SCFAs and maintaining the phagocytic ability and responsiveness of neutrophils.

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.

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.

Influence of endometritis on milk yield of zero-grazed dairy cows on smallholder farms in Rwanda

Endometritis being a post-partum uterine infection in dairy cows is likely with substantial production loss through reduction in milk yield (MY), discarded milk during treatment and withdrawal period, and increased cost of veterinary treatment. This study quantified the influence of endometritis on MY of zero-grazed dairy cows managed on smallholder farms in Rwanda. The study enrolled a total of 461 cows within their 21 to 60 days in milk to examine for clinical endometritis (CLE) and subclinical endometritis (SCLE). A cow was considered having endometritis if it was positive for at least one test (CLE or SCLE), otherwise was negative. The MY data were collected prospectively from endometritis positive and negative cows for 30-day post-endometritis diagnosis. Compared to cows negative for endometritis, the positive endometritis cows were 2.4 times more (29.7 vs. 70.3%) with daily MY 15.3% lower (7.5 ± 0.2 vs. 8.9 ± 0.3 litres; p<0.05), representing a reduction of 1.4 ± 0.2 litres of milk/cow/day. Of the CLE positive cows, 33.4% (104/311) were treated using different veterinary drugs, which resulted in 23.5% more discarded milk compared (p<0.05) to untreated positive cows. Discarded milk was higher (p<0.05) among cows treated with oxytetracycline (65.9 ± 4.4 litres) compared to cows treated with procaine penicillin G and dihydrostreptomycin (35.5 ± 2.7 litres). The percentage of total milk loss was much higher (45.6%) among CLE positive cows that received treatment compared to the untreated cows (16.3%). These results demonstrate a strong association between MY loss and endometritis. A timely diagnosis and treatment of the disease is recommended using conventional veterinary drugs that have zero withholding time for milk to reduce the MY loss and associated economic loss, estimated at 154 US$ in a lactation.

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.