Uterine Microbiota and Immune Parameters Associated with Fever in Dairy Cows with Metritis

OBJECTIVE

This study aimed to evaluate bacterial and host factors causing a fever in cows with metritis. For that, we investigated uterine microbiota using a metagenomic sequencing of the 16S rRNA gene (Study 1), and immune response parameters (Study 2) in metritic cows with and without a fever.

PRINCIPAL FINDINGS (STUDY1)

Bacterial communities were similar between the MNoFever and MFever groups based on distance metrics of relative abundance of bacteria. Metritic cows showed a greater prevalence of Bacteroidetes, and Bacteroides and Porphyromonas were the largest contributors to that difference. A comparison of relative abundance at the species level pointed to Bacteroides pyogenes as a fever-related species which was significantly abundant in the MFever than the MNoFever and Healthy groups; however, absolute abundance of Bacteroides pyogenes determined by droplet digital PCR (ddPCR) was similar between MFever and MNoFever groups, but higher than the Healthy group. The same trend was observed in the total number of bacteria.

PRINCIPAL FINDINGS (STUDY2)

The activity of polymorphonuclear leukocyte (PMN) and the production of TNFα, PGE2 metabolite, and PGE2 were evaluated in serum, before disease onset, at 0 and 3 DPP. Cows in the MNoFever had decreased proportion of PMN undergoing phagocytosis and oxidative burst compared with the MFever. The low PMN activity in the MNoFever was coupled with the low production of TNFα, but similar PGE2 metabolite and circulating PGE2.

CONCLUSION/SIGNIFICANCE

Our study is the first to show a similar microbiome between metritic cows with and without a fever, which indicates that the host response may be more important for fever development than the microbiome. Bacteroides pyogenes was identified as an important pathogen for the development of metritis but not fever. The decreased inflammatory response may explain the lack of a febrile response in the MNoFever group.

Selenium Plays a Protective Role in Staphylococcus aureus-Induced Endometritis in the Uterine Tissue of Rats

The essential trace element selenium (Se) modulates the functions of many regulatory proteins in signal transduction, conferring benefits in inflammatory diseases. Endometritis is a reproductive obstacle disease both in humans and animals. Staphylococcus aureus is the major pathogen that causes endometritis. The present study analyzes the protection and mechanism of Se-methylselenocysteine (MSC) and methylseleninic acid (MSA) on S. aureus-induced endometritis. An atomic fluorescence spectrophotometry study showed that the uterine Se content increased with the addition of MSC and MSA. Histopathology observation and TUNEL detection showed that Se supplementation displayed a greater defense against uterine inflammatory damage. The quantitative PCR (qPCR) and ELISA analyses showed that the expressions of tumor necrosis factor alpha (TNF-α) and interleukin-6 (IL-6) increased with S. aureus infection and decreased with the addition of MSC and MSA. The Toll-like receptor 2 (TLR2) expression showed the same status as the inflammatory cytokines. The Western blot results showed that the increased phosphorylation of IκBα and NF-κB p65 was also reduced by the addition of MSC and MSA. The qPCR and Western blot results also showed that the transcription expressions and the protein dissociation of caspase-9, caspase-3, caspase-7, caspase-6, and poly(ADP-ribose) polymerase (PARP), which were increased by S. aureus infection, were inhibited by Se supplementation. All of the results displayed that the protection conferred by MSC was stronger than MSA. The present study indicated the Se supplementation might be a potential prevention and control measure for S. aureus-induced endometritis.

[Findings in uteri and ovaries from Eringer cows slaughtered due to fertility problems]

Eringer cows are often slaughtered due to fertility problems which result from inflammatory and degenerative changes of the uterus or hormonal imbalances. Twenty-one genital tracts from Eringer cows suffering from fertility problems were collected in the abattoir. The purpose of the study was the macroscopic evaluation of the ovaries and the uterus followed by a histological and microbiological analysis of the uterus. Data from inseminations and calvings were provided by the Eringer breeding association and through the internet portal www.agate.ch. Median age of the cows was 6.9 years, number of calves per cow was 2.5 and median period between last calving and slaughter was 1.5 years. In 13 from 21 of the urogenital tracts examined, macroscopic abnormalities of the ovaries and/or histologic or microbiologic findings in the uterus could explain fertility-associated slaughter.

[NEW APPROACHES TO THE EARLY DIAGNOSIS OF INTRAUTERINE VIRAL INFECTIONS IN NEWBORNS]

The importance of intrauterine viral infections in newborns pathology remain incompletely understood, as there is the problem of early verification of the etiologic pathogen. The aim of the study was to develop diagnostic criteria for intrauterine viral infections by introducing rapid diagnostic methods, the study of perinatal factors, medical history, clinical course and laboratory data. Clinical and laboratory examination 834 mothers and their newborn patients with suspected intrauterine infection. We observed 224 children with verified intrauterine viral infection. Studied the history of perinatal risk factors, clinical features and laboratory data. Studies have shown that the predominant form of mixed infections (85.7%). On the basis of statistical methods developed diagnostic criteria and algorithm of differential diagnosis of all possible variants of infection. Testing diagnostic algorithm has shown high reliability of diagnostic criteria, which allows recommend them for clinical use.

Puerperal influence of bovine uterine health status on the mRNA expression of pro-inflammatory factors

After parturition, uterine bacterial infections lead to inflammatory processes such as subclinical/clinical endometritis with high prevalence in dairy cows. Endometrial epithelial cells participate in this immune response with the production of pro-inflammatory factors. The objective of the present study was to evaluate the endometrial mRNA expression pattern of pro-inflammatory factors during a selected postpartum (pp) period. Dairy cows with three different uterine health conditions on days 24-30 pp (healthy: n = 11, subclinical endometritis: n = 10, clinical endometritis: n = 10) were sampled using the cytobrush technique. Subsequently, each cow was sampled 3 more times in weekly intervals (days 31-37 pp; days 38-44 pp; days 45-51 pp). Samples were subjected to mRNA analysis performed by RT-qPCR. Additionally, an analysis of cultivable bacteria was performed at the early/late stage of the selected puerperal period. mRNA expression of 16 candidate genes was analyzed by using two different approaches. The first approach referred to the initial grouping on days 24-30 pp to reveal long-term effects of the uterine health on the subsequent puerperal period. The second approach considered the current uterine health status at each sampling to elucidate the impact of different points in time. Long-term effects seem to appear for chemokines, prostacyclin synthase and prostaglandin D2 synthase. If related to the current uterine health, the majority of candidate genes were significantly higher expressed in endometritic cows on days 45-51 pp in contrast to earlier stages of the puerperium. Microbiological analysis revealed the significantly higher prevalence of Trueperella pyogenes findings in cows with clinical endometritis on days 24-30 pp, but no correlations were found on days 45-51 pp. In conclusion, a strong immune response to subclinical/clinical endometritis in the late puerperium may be related to the negative impact of these conditions on reproductive performance in dairy cows.

[Pathogenetic substantiation of surgical treatment safety in early reproductive losses]

Early loss of pregnancy is associated with high rate of chronic inflammatory processes of genital organs. While still and tubal pregnancy a multicomponent associations of microorganisms in genital ways are revealed, accordingly, in 66.7 and 48.9% women, morphological signs of inflammatory process--in 72.2 and 51.1%. Application of endoscopic methods of diagnosis and treatment of women in early loss of pregnancy is highly effective, permits to reveal comorbidities, to perform miniinvasive organ preserving interventions in necessary volume. Performance of complex anti-inflammatory treatment of women in early loss of pregnancy is substantiated with the objective to escape negative outcomes, and for improvement of immediate and late results of surgical treatment.

Silent chorioamnionitis and associated pregnancy outcomes: a review of clinical data gathered over a 16-year period

OBJECTIVE

To assess neonatal outcomes and associated findings in pregnant women identified after delivery as having had underlying subclinical chorioamnionitis by either histology or bacterial culture.

METHODS

In 16 years, 8974 clinical, histological, and bacterial culture data were obtained retrospectively.

RESULTS

Placental histology was analyzed in 4237 pregnancies (2785 term and 1452 preterm) and 4737 amniotic cavity cultures were obtained during 5446 cesarean deliveries (3268 term and 1469 preterm). Histological results and bacterial cultures were both available in 1270 of the preterm deliveries. Histology revealed inflammation, suggestive of infection, in 13.6% of placentas. Subclinical acute chorioamnionic inflammation was confirmed in 142 out of 2785 term pregnancies (5.1%) and in 436 out of 1452 preterm pregnancies (30.0%, P<0.001). Bacteriological culture of the intrauterine cavity was obtained from the lower uterine segment of the uterus during cesarean section. A positive culture was found in 19.9% of all cases (941/4737), this proportion was significantly higher in preterm deliveries (343/1273, 26.9%) than in term (17.3%, P<0.001). The lower the birth-weight or gestational age, the higher the frequency of silent infections in the uterine cavity.

CONCLUSIONS

Our study findings support the association between intra-amniotic infections and preterm delivery.

Determination of selected parameters for non-specific and specific immunity in cows with subclinical endometritis

Endometritis in dairy cow herds is a serious economic problem all over the world due to the large economic losses. The aim of the study was a comparative evaluation of selected indicators of non-specific and specific immunity in cows with subclinical endometritis and in cows without inflammation of the uterus. The study was performed on 40 cows on day 65 after delivery. Based on the results of cytological tests, the cows were divided into two groups: experimental (subclinical endometritis) and control (20 cows in each group). A flow cytometric analysis was performed for the leukocyte surface molecules CD4, CD8, CD14, CD21, CD25. Moreover the phagocytic activity of granulocytes and monocytes/macrophages in peripheral blood and uterine washings was determined. It has been demonstrated that the percentage of phagocytic granulocytes and monocytes/macrophages in both the peripheral blood and uterine washings was significantly lower for cows with subclinical endometritis when compared to cows undergoing a normal puerperal period (p<0.001). A significant (p≤0.001) decrease in the percentage of CD4+, CD14+, CD25+ and CD4+CD25+ leukocytes was also observed in peripheral blood of the cows from the experimental group. In uterine washings a significant decrease (p<0.001) in CD21+ and increase in CD8+ lymphocytes was detected. The results indicate that dysfunction of cell immunity coexisting with subclinical endometritis may be the main factor causing advanced inflammation of the uterus. Knowledge of immunological mechanisms observed in cows with subclinical endometritis could aid in choosing the right adjuvant therapy using immunomodulating agents.

Bacterial infections in Myd88-deficient mice

Three breeding colonies of Myd88(-/-) mice had a history of significant morbidity and mortality. Although strain-specific poor reproductive performance might explain neonatal death and dystocia, mice were found dead or required euthanasia because of moribundity, distended abdomen, head tilt, and seizures. Histopathology results included bacteremia, placentitis, metritis, peritonitis with abscess formation, and suppurative meningoencephalitis. Intralesional gram-negative coccobacilli were present, often in extremely high number. Cultures of samples of the cardiac blood of a mouse and from water-bottle sipper tubes provided to some affected mice grew Pseudomonas aeruginosa. In addition, affected tissues from 2 mice and feces from a third tested PCR-positive for P. aeruginosa. Although the mice had received autoclaved reverse-osmosis-purified drinking water, we suspect that the mice were inoculated with P. aeruginosa through contaminated sipper tubes. Because of the deficiency in most of the Toll-like receptor signaling pathways, these Myd88(-/-) mice were unlikely to have developed competitive innate and adaptive immune responses, resulting in bacterial infections. These clinical cases underscore the importance of understanding how genotype, phenotype and environment affect animal health. Sound husbandry and experimental practices are needed to prevent the exposure of immuno-deficient mice to pathogens.

Streptococcus equi subsp. zooepidemicus isolates from equine infectious endometritis belong to a distinct genetic group

Streptococcus equi subsp. zooepidemicus is the pathogen most commonly isolated from the uterus of mares. S. zooepidemicus is an opportunistic pathogen and part of the resident flora in the caudal reproductive tract. The aim of this study was to investigate whether a genotypically distinct subpopulation of S. zooepidemicus is associated with endometritis in the mare, by genotyping and comparing uterine S. zooepidemicus strains with isolates from the vagina and clitoral fossa. Mares with (n=18) or without (n=11) clinical symptoms of endometritis were included. Uterine samples were obtained using a guarded endometrial biopsy punch, whereas a swab was used to recover samples from the cranial vagina and the clitoral fossa. If S. zooepidemicus was present, up to three colonies were selected from each anatomical location (max. 9 isolates per mare). Bacterial isolates were characterized by pulsed-field gel electrophoresis (PFGE) and multilocus sequence typing (MLST). S. zooepidemicus was isolated from the endometrium of 12 mares. A total of 88 isolates were analyzed by PFGE: 31 from the endometrium, 26 from the cranial vagina and 31 isolates from the clitoral fossa. For MLST 21 isolates were chosen. Results demonstrated a higher genetic similarity of the isolates obtained from infectious endometritis compared to isolates obtained from the caudal reproductive tract. In conclusion, we demonstrate for the first time that a genetically distinct group of S. zooepidemicus is associated with infectious endometritis in the mare.

The diagnosis and prevalence of subclinical endometritis in cows evaluated by different cytologic thresholds

The aims of our study were to determine (1) how the prevalence of cytologically determined subclinical endometritis varies when using three different cytological threshold ratios to categorize cows as either with or without endometritis, (2) how the number of animals categorized as having endometritis changes from the fourth to the sixth wk postpartum when using each threshold, (3) how subclinical endometritis influences the number of days open, and (4) how the results of cytological and bacterial examinations correlate. To answer these questions, 222 clinically healthy cows in two herds were examined in the fourth (Exam 1) and the sixth wk (Exam 2) postpartum, when endometrial surface scrapings for bacteriologic and cytologic examination were collected by cytobrush from their uterine horns. After each examination, all cows were categorized using three different thresholds: (1) > 18% polymorphonuclear leucocytes in Exam 1 and > 10% in Exam 2, (2) > 8% in both exams, and (3) > 5% in both exams. It was found that: (1) The number of cows categorized as having endometritis increased as the threshold was lowered, and ranged from 18.9% to 75.4% according to herd, time of examination, and the threshold used; (2) with all three thresholds and in both herds, the number of cows categorized as having endometritis in Exam 1 was approximately double that in Exam 2; whereas depending on the herd and the threshold used, 6.1% to 17.0% of the cows that were negative in the first exam were positive in the second, and 7.4% to 33.3% were positive in both exams; (3) cows were open for a significantly greater number of days if categorized as having endometritis with the first threshold in Exam 1 (mean ± SEM 151.5 ± 9.5 vs. 115.9 ± 7.8; P < 0.01), or with either the first or the second threshold in Exam 2 (mean ± SEM 155.0 ± 15.0 vs. 125.1 ± 6.6; P < 0.05); and (4) the most common bacteria were Streptococcus acidominimus and Escherichia coli, and the correlation between cytologic and bacteriologic findings was low (Φ = 0.08 to 0.17 for different tested thresholds). Subclinical endometritis seems to be associated more with the postpartum recovery of the endometrium than with bacterial infection.

Diversity and succession of bacterial communities in the uterine fluid of postpartum metritic, endometritic and healthy dairy cows

The diversity of the uterine bacterial composition in dairy cows is still poorly understood, although the emerging picture has shown to be increasingly complex. Understanding the complexity and ecology of microorganisms in the uterus of postpartum dairy cows is critical for developing strategies to block their action in reproductive disorders, such as metritis/endometritis. Here, we used PCR-Denaturing Gradient Gel Electrophoresis (DGGE) and DNA pyrosequencing to provide a comprehensive description of the uterine bacterial diversity and compare its succession in healthy, metritic and endometritic Holstein dairy cows at three intervals following calving. Samples were collected from 16 dairy cows housed in a dairy farm located in upstate New York. PCR-DGGE revealed a complex profile with extensive differences in the community structure. With few exceptions, clustering analysis grouped samples from cows presenting the same health status. Analysis of >65,000 high-quality 16S rRNA gene sequences showed that the uterine bacterial consortia, regardless of the health status, is mainly composed of members of the phyla Bacteroidetes, Fusobacteria, Firmicutes, Proteobacteria, and Tenericutes. In addition to these co-dominant phyla, sequences from Spirochaetes, Synergistetes, and Actinobacteria appear less frequently. It is possible that some sequences detected in the uterine fluid resulted from the presence of fecal or vaginal contaminants. Overall, the bacterial core community was different in uterine fluid of healthy cows, when compared to cows suffering from postpartum diseases, and the phylogenetic diversity in all the combined samples changed gradually over time. Particularly at the 34–36 days postpartum (DPP), the core community seemed to be specific for each health status. Our finding reveals that the uterine microbiota in dairy cows varies according with health status and DPP. Also, it adds further support to the hypothesis that there is uterine contamination with diverse bacterial groups following calving and emphasizes the role of unidentified microorganisms in this context.

Chlamydia muridarum enters a viable but non-infectious state in amoxicillin-treated BALB/c mice

In culture, exposure to penicillin and other stressors induce chlamydiae to enter a non-infectious but viable state termed persistence. Chlamydiae may reenter their normal developmental cycle after stressor removal. Though aberrant RB similar to those present in culture models of persistence have been observed within infected tissues, the existence of persistent chlamydiae has not been definitively demonstrated in vivo. As a result, the role of persistent organisms in pathogenesis is undefined. In order to establish an experimentally tractable model of in vivo persistence, Chlamydia muridarum vaginally-infected mice were gavaged with either water or amoxicillin (amox). Vaginal swabs were collected for chlamydial titration and RNA isolated for quantification of pre-16s rRNA. Uterine tissue was analyzed by transmission electron microscopy (TEM). Although amox-treatment reduced vaginal shedding by >99%, C. muridarum pre-16s rRNA accumulation was unchanged by treatment. These data indicate that the amox-exposed organisms were viable but not infectious. Furthermore, TEM analyses demonstrated that inclusions in amox-treated animals contained primarily large, aberrant RB, but those observed in untreated control animals were normal. Collectively, these data suggest that amoxicillin treatment induces C. muridarum to enter the persistent state in vivo. This model also represents the first experimentally tractable animal model of chlamydial persistence.

Host genetic background impacts disease outcome during intrauterine infection with Ureaplasma parvum

Ureaplasma parvum, an opportunistic pathogen of the human urogenital tract, has been implicated in contributing to chorioamnionitis, fetal morbidity, and fetal mortality. It has been proposed that the host genetic background is a critical factor in adverse pregnancy outcome as sequela to U. parvum intra-amniotic infection. To test this hypothesis we assessed the impact of intrauterine U. parvum infection in the prototypical TH1/M1 C57BL/6 and TH2/M2 BALB/c mouse strain. Sterile medium or U. parvum was inoculated into each uterine horn and animals were evaluated for intra-amniotic infection, fetal infection, chorioamnionitis and fetal pathology at 72 hours post-inoculation. Disease outcome was assessed by microbial culture, in situ detection of U. parvum in fetal and utero-placental tissues, grading of chorioamnionitis, and placental gene expression of IL-1α, IL-1β, IL-6, TNF-α, S100A8, and S100A9. Placental infection and colonization rates were equivalent in both strains. The in situ distribution of U. parvum in placental tissues was also similar. However, a significantly greater proportion of BALB/c fetuses were infected (P<0.02). C57BL/6 infected animals predominantly exhibited mild to moderate chorioamnionitis (P<0.0001), and a significant reduction in placental expression of IL-1α, IL-1β, IL-6, TNF-α, S100A8, and S100A9 compared to sham controls (P<0.02). Conversely, severe protracted chorioamnionitis with cellular necrosis was the predominant lesion phenotype in BALB/c mice, which also exhibited a significant increase in placental expression of IL-1α, IL-1β, IL-6, TNF-α, S100A8, and S100A9 (P<0.01). Fetal pathology in BALB/c was multi-organ and included brain, lung, heart, liver, and intestine, whereas fetal pathology in C57BL/6 was only detected in the liver and intestines. These results confirm that the host genetic background is a major determinant in ureaplasmal induced chorioamnionitis with fetal infection and fetal inflammatory response.

The effect of intrauterine administration of mannose or bacteriophage on uterine health and fertility of dairy cows with special focus on Escherichia coli and Arcanobacterium pyogenes

The objective of this study was to evaluate the effects of intrauterine administration of 50 g of ultrapure mannose or a bacteriophage cocktail and the presence of Escherichia coli and Arcanobacterium pyogenes in the uterine lumen on uterine health and reproductive performance of lactating dairy cows. The study was conducted on a commercial dairy farm located near Ithaca, New York, from May 4 to January 20, 2011, and 597 cows were enrolled. The cows were divided randomly into 3 treatment groups, and treatments were administered at 2 ± 1 d in milk (DIM). Treatment 1 consisted of intrauterine administration of 50 g of ultrapure mannose powder divided in 4 pills; treatment 2 consisted of intrauterine administration of a bacteriophage cocktail that included 4 different phages in one pill, with a dose of approximately 10⁷ plaque-forming units; and treatment 3 consisted of intrauterine administration of one empty pill (control). Intrauterine fluid swabs were collected on day of treatment and at 10 ± 3 DIM; uterine lavage samples were collected at 35 ± 3 DIM. Swabs and uterine lavage samples were cultured for E. coli and A. pyogenes. The intrauterine administration of mannose and bacteriophage did not affect uterine health, reproduction performance, or outcome of intrauterine secretion cultures for E. coli and A. pyogenes. Prevalence of intrauterine E. coli at 2 ± 1 DIM and A. pyogenes at 2 ± 1, 10 ± 3, and 35 ± 3 were affected by retained placenta. Additionally, prevalence of intrauterine E. coli at 10 ± 3 and A. pyogenes at 35 ± 3 DIM were associated with metritis, and cows that were diagnosed with clinical endometritis at 35 ± 3 DIM had greater prevalence of intrauterine E. coli at 2 ± 1 DIM and A. pyogenes at 35 ± 3 DIM. Furthermore, cows positive for E. coli at 2 ± 1 and 10 ± 3 DIM and for A. pyogenes at 10 ± 3 DIM had 1.63, 2.34, and 1.54 increased odds of having metritis. Cows positive for A. pyogenes at 35 ± 3 DIM and for E. coli at 2 ± 1 DIM had 19.8 and 2.66 higher odds of being diagnosed with clinical endometritis, respectively. Additionally, cows negative for E. coli at 2 ± 1 DIM were 1.39 times more likely to conceive than cows positive cows for E. coli.

[The proteins of fast phase of inflammation in prognosis of condition of newborn in case of pregnancy complicated by hydramnion and under the risk of intrauterine infection]

The content of alpha-macroglobulin associated with pregnancy, alpha2-glycoprotein, alpha1-antitripsin, and lactolerrin in blood serum of pregnant women and umbilical serum under hydramnion and risk of development of intrauterine infection of fetus is investigated. It is demonstrated that in case ofpresence in blood of pregnant woman of G-antibodies to C. trachomatis under low titers (1:20, 1:40) the increase of levels of alpha-macroglobulin, alpha2-glycoprotein, al-antitripsin and especially of lactoferrin in serum of pregnant women testifies the high risk of presence of intrauterine infection of fetus and probability of birth of child with low values on Apgar scale.

Intrauterine infection and preterm labor

Preterm labor is defined as labor that begins before 37 completed weeks of pregnancy. More than 12% of infants born in the USA are preterm. At least 40% of preterm births are associated with intrauterine infection. Toll-like receptors (TLRs) are members of a family of cell-surface proteins responsible for recognition of a diverse spectrum of bacterial, viral and fungal pathogens. TLRs initiate the host innate (i.e. non-adaptive) immune response, inducing a proinflammatory cascade involving cytokines, chemokines, prostaglandins, and other effector molecules that result in the characteristic phenomena of labor, such as uterine contractions and rupture of fetal membranes. These cascades may also be activated by mechanisms that are not primarily infectious but are accompanied by inflammatory responses. Now that the molecular mechanisms linking infection and labor have been, to a large extent, elucidated, the challenge is to identify points of overlap with non-infectious causes of labor and to find intervention strategies that can minimize the negative impact of preterm delivery.

[Infectious agent detection in reproductive disorders in swine herds. Retrospective evaluation of diagnostic laboratory examinations]

OBJECTIVE

The detection rate of various viral and bacterial agents causing reproductive failure in sows was analysed.

MATERIAL AND METHODS

Samples from abortion/uterus (n=714), sera from weak born piglets (n=317), cervical swabs (n=881) and urogenital organs from slaughtered sows (n=416) that had been submitted between January 2006 and June 2009 were included in this analysis. Various PCR assays were run to detect PRRSV, PCV2, PPV, Chlamydia spp. and Leptospira spp. Other bacterial agents were examined using standard cultural methods.

RESULTS

In material from abortion, detection rates of 14.7% for PCV2 and 6.8% for PRRSV EU genotype were revealed using PCR screening. The other agents were detected in single cases only (PPV 2.2%, PRRSV US genotype 1.8%, Chlamydia spp. 1.0%, Leptospira spp. 0.8%). Single PCR yielded a significantly higher detection rate for PCV2 than PCR screening. Comparing results from abortion/uterus and serum samples from weak born piglets, a significantly higher detection rate of PCV2 and PRRSV was found in sera. Bacteriological examination revealed bacterial agents in more than 75% of all cervical swabs. However, half of them had to be considered as contaminated due to the diversity of the isolated bacteria. Bacteriological testing of urogenital organs from slaughtered sows yielded positive results in 60% of all samples, with a remarkably lower proportion of contaminated samples of 7.4%.

CONCLUSION

It is assumed that 60-70% of all cases of reproductive failure are similarly not caused by primary infections. If PRRSV infection is suspected, examination of serum samples from weak born piglets is much better than the testing of foetuses or other material from abortion. Due to poor detection rates, the examination of foetuses/abortion material by screening PCR cannot be recommended. In the case of bacterial infections of the urogenital system, the cultural examination of organs from slaughtered sows is more often successful than the testing of cervical swabs.

Time-dependent mRNA expression of selected pro-inflammatory factors in the endometrium of primiparous cows postpartum

BACKGROUND

Inflammatory processes and infections of the uterine wall must be accepted as a physiological event in dairy cows after calving. This might result in clinical or subclinical endometritis which is assumed to impair reproductive performance in the current lactation. Several cytokines and acute phase proteins have been discussed as local and systemic mediators of these inflammatory processes. The aim of the present study was to investigate the endometrial mRNA expression of the chemokine CXC ligand 5 (CXCL5), interleukin 1β (IL1B), IL6, IL8, tumour necrosis factor alpha (TNF), prostaglandin-endoperoxide synthase 2 (PTGS2) and haptoglobin (HP) in the postpartum period.

METHODS

Endometrial samples were obtained from primiparous cows (n = 5) on days 10, 17, 24, 31, 38 and 45 postpartum (pp) using the cytobrush technique. Cytological smears were prepared from cytobrush samples to determine the proportion of polymorphonuclear neutrophils (PMN). Total RNA was extracted from endometrial samples, and real-time RT-PCR was performed.

RESULTS

A time-dependent mRNA expression of the investigated factors was found for the course of the postpartum period. In detail, a significantly higher expression of these factors was observed on day 17 pp compared to day 31 pp. Furthermore, the proportion of PMN peaked between days 10-24 pp and decreased thereafter to low percentages (< 5%) on day 31 pp and thereafter. In addition, CXCL5, IL1B, IL8 and HP mRNA expression correlated significantly with the proportion of PMN (P < 0.05). A significantly higher CXCL5, IL1B, IL6, IL8, PTGS2 and TNF mRNA content was observed in samples from cows with an inflamed endometrium compared with samples from cows with a healthy endometrium (P < 0.05).

CONCLUSIONS

These results show that inflammatory cytokines and acute phase proteins are expressed in the bovine endometrium in a time-related manner during the postpartum period, with a significant expression peak on day 17 pp as a possible mucosal immune response in the uterus. The evaluation of the expression patterns of such candidate genes may reveal more information than only determining the percentage of PMN to judge the severity of an inflammation.

Recent advances in understanding the microbiology of the female reproductive tract and the causes of premature birth

Data derived from molecular microbiological investigations of the human vagina have led to the discovery of resident bacterial communities that exhibit marked differences in terms of species composition. All undergo dynamic changes that are likely due to intrinsic host and behavioral factors. Similar types of bacteria have been found in both amniotic fluid and the vagina, suggesting a potential route of colonization. Given that not all of the species involved in intrauterine infections are readily cultivated, it is important that culture-independent methods of analysis must be used to understand the etiology of these infections. Further research is needed to establish whether an ascending pathway from the vagina to the amniotic cavity enables the development of intrauterine infections.

Results of bacteriological and cytological examinations of the endometrium of subfertile mares in stud farms in Serbia

Uterine microbiology, antimicrobial susceptibility and endometrial cytology were investigated in a total of 51 mares with fertility problems from 16 different stud farms in Serbia. Uterine cultures were performed after collection with a double guarded uterine swab, and endometrial cytology was evaluated after collection of endometrial cells with a special device (cytology brush). In 21 of 51 mares, at least one bacterial species was isolated from the uterus; the most frequent were Streptococcus equi subsp. zooepidemicus (13 isolates) and E. coli (four isolates). All isolates of Streptococcus equi subsp. zooepidemicus were susceptible to penicillin. Results from endometrial cytology were inconsistent; in 17 animals with positive bacteriological culture, cytology was not altered. It can be concluded that in Serbia, as in many other contries, Streptococcus equi subsp. zooepidemicus is the main cause for equine endometritis. It can be easily diagnosed by uterine culture but endometrial cytology does not always prove the existence of an endometrial infection with this agent.

[Impact of intrauterine infection on long-term brain development of premature rats]

OBJECTIVE

To investigate the impact of intrauterine infection induced by LPS injection on long-term brain development of premature rats.

METHODS

Eighteen day-gestation pregnant rats were randomly assigned to a control group receiving an intraperitoneal injection of normal saline, and two infection groups that were intraperitoneally injected with 0.3 mg/kg or 0.6 mg/kg LPS. Twenty-four hours after injection, 7 pregnant rats of each group were sacrificed. The pathological changes of the placenta after hematoxylin and eosin staining were observed under a light microscope. The neural cell apoptosis of fetal brains was examined by the TUNEL assay. The remained pregnant rats were induced to labour before 21 gestation days. The long-term brain development of premature rats was tested with the Y type electric maze on postnatal day 42.

RESULTS

Obvious pathological changes were observed in the placenta in the infection groups. The apoptotic neural cells in the fetal brain increased in the infection groups compared with that in the control group (32.41+/-5.36 in the 0.3 mg/kg infection group and 66.41+/-7.61 in the 0.6 mg/kg infection group vs 8.00+/-0.36 in the control group; P<0.01). The number of trials to criterion in the Y type maze test in the infection groups was much more than that in the control group [117.8+/-8.7 (0.3 mg/kg infection group) and 194.4+/-13.7 (0.6 mg/kg infection group) vs 56.8+/-3.7 (control group); P<0.01]. The number of correct reactions in memory retaining in the infection groups was lower than that in the control group (0.62+/-0.09 in the 0.3 mg/kg infection group and 0.37+/-0.09 in the 0.6 mg/kg infection group vs 0.92+/-0.06 in the control group; P<0.05).

CONCLUSIONS

Intrauterine infection can cause fetal rats' neural cell apoptosis and affect adversely long-term brain development of neonatal rats.

Specific strains of Escherichia coli are pathogenic for the endometrium of cattle and cause pelvic inflammatory disease in cattle and mice

Background

Escherichia coli are widespread in the environment and pathogenic strains cause diseases of mucosal surfaces including the female genital tract. Pelvic inflammatory disease (PID; metritis) or endometritis affects ∼40% of cattle after parturition. We tested the expectation that multiple genetically diverse E. coli from the environment opportunistically contaminate the uterine lumen after parturition to establish PID.

Methodology/Principal Findings

Distinct clonal groups of E. coli were identified by Random Amplification of Polymorphic DNA (RAPD) and Multilocus sequence typing (MLST) from animals with uterine disease and these differed from known diarrhoeic or extra-intestinal pathogenic E. coli. The endometrial pathogenic E. coli (EnPEC) were more adherent and invasive for endometrial epithelial and stromal cells, compared with E. coli isolated from the uterus of clinically unaffected animals. The endometrial epithelial and stromal cells produced more prostaglandin E₂ and interleukin-8 in response to lipopolysaccharide (LPS) purified from EnPEC compared with non-pathogenic E. coli. The EnPEC or their LPS also caused PID when infused into the uterus of mice with accumulation of neutrophils and macrophages in the endometrium. Infusion of EnPEC was only associated with bacterial invasion of the endometrium and myometrium. Despite their ability to invade cultured cells, elicit host cell responses and establish PID, EnPEC lacked sixteen genes commonly associated with adhesion and invasion by enteric or extraintestinal pathogenic E. coli, though the ferric yersiniabactin uptake gene (fyuA) was present in PID-associated EnPEC. Endometrial epithelial or stromal cells from wild type but not Toll-like receptor 4 (TLR4) null mice secreted prostaglandin E₂ and chemokine (C-X-C motif) ligand 1 (CXCL1) in response to LPS from EnPEC, highlighting the key role of LPS in PID.

Conclusions/Significance

The implication arising from the discovery of EnPEC is that development of treatments or vaccines for PID should focus specifically on EnPEC and not other strains of E. coli.