Incidence of uterine infections, major bacteria and antimicrobial resistance in postpartum dairy cows in southern Ethiopia.

BACKGROUND: Uterine infections, primarily caused by bacterial pathogens, pose a significant problem for dairy farmers worldwide, leading to poor reproductive performance and economic losses. However, the bacteria responsible for uterine infections have not been adequately studied, nor has the antibiotic susceptibility of the causative bacteria been frequently tested in Ethiopia. This study aims to estimate the cumulative incidence of uterine infections in postpartum dairy cows, identify bacterial causes and determine antimicrobial susceptibility profile of the isolated bacteria. METHODS: A prospective cohort study was conducted in which 236 cows from 74 dairy farms were monitored biweekly from calving to 90 days postpartum for metritis, endometritis and other disorders. Aseptic uterine swab samples were collected from 40 cows with uterine infections. The samples were cultured, and the isolated bacteria were tested for antimicrobial susceptibility using the disk diffusion method. RESULTS: Out of 236 cows monitored during the postpartum phase, 45 (19.1%) were found to have contracted uterine infection. The cumulative incidence of metritis was 11.4% (n = 27), while the cumulative incidence of endometritis was 7.6% (n = 18). Of the 40 cultured swab samples, 29 (72.5%) had one or more bacteria isolated. The most commonly isolated bacteria were Escherichia coli (45%), coagulase-positive staphylococci (30%), and Klebsiella spp. (22.5%). Other bacterial spp, including Arcanobacterium pyogenes (12.5%), Fusobacterium spp. (12.5%), Enterobacter aerogenes (12.5%), coagulase-negative staphylococci (12.5%), Streptococcus spp. (7.5%), Salmonella spp, (5%) Proteus spp (5%) and Pasteurella spp (2.5%) were also isolated. All of the isolated bacteria demonstrated resistance to at least one of the antimicrobials tested. Multidrug resistance was observed in E. coli, Klebsiella spp., A. pyogenes, and Fusobacterium spp. Gentamicin was found to be the most effective antimicrobial against all bacteria tested, while tetracycline was the least effective of all. CONCLUSION: The study found that a significant proportion of cows in the population were affected by uterine infections and the isolated bacteria developed resistance to several antimicrobials. The study emphasizes the need for responsible use of antimicrobials to prevent the emergence of antimicrobial resistance. It also highlights the importance of raising awareness among dairy farmers to avoid the indiscriminate use of antibiotics and its consequences.

The dogma of the sterile uterus revisited: does microbial seeding occur during fetal life in humans and animals?

In brief: Opposing conclusions have been drawn regarding the presence of viable bacteria in the healthy pregnant uterus. Current evidence in humans and animals suggests that fetomaternal tissues present only traces of bacteria whose viability is still to be proven. Abstract: The debate about the pioneer colonization of the fetus is still open, being the 'in utero colonization' hypothesis versus the 'sterile womb paradigm' the two opposing sides. The seed in this field of research sprouted in human medicine in the last decade and became a central topic in other mammals as well. We aimed to review the literature on bacterial colonization of the healthy placenta, amniotic fluid, and meconium as representatives of the fetal environment. What emerges is that confirming the colonization of fetomaternal tissues by viable bacteria is challenging in humans as well as in animals. Contamination represents the major risk in this type of research as it can be related to different parts of the study design. Sampling at natural parturition or postpartum introduces risk for colonization by the vaginal microbiome of the mother or from the environment. Culture does not reveal the presence of unculturable microorganisms, and sequencing does not allow confirming bacterial viability, while also introducing the variability associated with the data analysis. Therefore, on the basis of the present review, we provide some guidelines on the best practices when performing this type of studies. What emerges from the current literature in humans and animals is that fetomaternal tissues are characterized by a very low biomass, that the viability of bacteria eventually present is still to be confirmed, while massive colonization happens at birth, priming the individual, regardless of the species.

Exploring the microbiome of two uterine sites in cows.

Bacterial communities in the mammalian reproductive system can be rich and diverse, differing in structure and quantity depending on location. In addition, its microbiome is associated with the state of health of this tract and reproductive success. This study evaluated the microbiome composition of the uterine body (UB) and uterine horn mucosa (UH) samples using 16S rRNA sequencing of samples extracted from cows in the Amazon region. It was observed that four main phyla were shared between the uterine sites: Actinobacteria, Bacteroidetes, Firmicutes, and Proteobacteria. Linear discriminant analysis effect size and heat tree analysis showed that members of Lachnospiraceae (NK3A20 group) and Oscillospiraceae were significantly more abundant in the UB than in UH. In addition, there are more unique genera in the UB than in the UH. A higher bacterial load in UB than in UH is expected because of the exposure to external factors of UB. However, comparing the site's communities through beta diversity did not generate well-defined clustering. Thus, it can be attributed to the closeness of the sites, which would make the niches similar ecologically and microbiologically. Therefore, this research provides knowledge to understand biomarkers in the prior reproduction period.

Bacteria Isolated From Equine Uteri in The United Arab Emirates: A Retrospective Study.

The United Arab Emirates (UAE) presents a unique environment in which to breed horses with a non-physiological breeding season coupled with high temperatures and humidity for much of the year. This study aimed to describe bacterial isolates from the uteri of mares in the UAE and compare them to those reported elsewhere in the world. Bacterial antibiotic resistance was also analyzed to give a starting point for future monitoring. A total of 2,022 swabs taken over five breeding seasons from the endometrium (n = 1,350) or from uterine lavages (n = 672) were submitted for microbiological culture and antibiotic sensitivity testing. At 48 hours post-inoculation 616 of 2,022 (30.5%) of cultures showed microbial growth from which 690 isolates were identified. Most positive plates (548 of 616; 89%) grew one isolate; 68 cultures had two (62 of 616; 10.1%) or three (6 of 616; 1%) isolates. The most frequently isolated bacteria were ß-hemolytic Streptococcus (36.5%; 252 of 690), E. coli (10.6%; 73 of 690), P. aeruginosa (10.1%; 70 of 690), K. pneumoniae (8.8%; 61 of 690) and Aeromonas hydrophila (4.1%; 28 of 690). The lowest level of antibiotic susceptibility for all isolates was shown by trimethoprim-sulphonamide (36.4%; 198 of 544), with amikacin showing the highest (76.1%; 271 of 356). A significant decrease in susceptibility to doxycycline, enrofloxacin, and erythromycin, but a significant increase for amoxicillin with clavulanic acid, was seen for ß-hemolytic Streptococcus. Decreasing susceptibility of trimethoprim-sulphonamide between two time periods was seen for E. coli. Compared to other studies UAE-based mares had a high incidence of P. aeruginosa and K. pneumoniae isolates, whereas E. coli was represented far less frequently as an isolate.

Tracing the source and route of uterine colonization by exploring the genetic relationship of Escherichia coli isolated from the reproductive and gastrointestinal tract of dairy cows.

The source and route of bacterial colonization of the uterus are still not established. The objective was to investigate the source and route of bacterial colonization of the uterus by exploring the genetic relationship among E. coli strains isolated from the gastrointestinal and the reproductive tract of dairy cows pre- and postpartum. Secondarily, uterine health status (metritis vs. healthy) was evaluated. Cows (n = 34) had the rectoanal junction (RAJ), vulva, and vagina swabbed every three days starting six days before expected calving until nine days postpartum. The uterus was swabbed postpartum. A blood sample was collected at all time points, but cultures were negative. Whole-genome sequencing was performed on 44 isolates recovered from eight cows (four metritic and four healthy) with growth on selective E. coli media from the RAJ, vulva and/or vagina and uterus. Clonal isolates were found in the RAJ or the vulva prepartum and in the vulva, vagina or uterus postpartum. Clonal isolates were also found in the RAJ, the vulva, the vagina and the uterus postpartum. Clonal isolates were found in individual cows and different cows. Absence of clustering based on virulence factor genes and all genes indicate no strain specificity to body site or uterine health status. These findings indicate that the gastrointestinal tract is the likely source of bacteria that colonize the reproductive tract via ascending colonization of the uterus through the lower genital tract. Additionally, cow to cow transmission occurs, and strains are not specific to body site or to health status.

Infectious Endometritis in Mares: Microbiological Findings in Field Samples.

Endometritis is a major cause of infertility and subfertility in the mare. Early diagnosis and identification of the pathogens involved in infectious endometritis are crucial to initiate correct treatments in time, in order to optimize fertility and reduce the risk of bacterial resistance development. In this retrospective study (from 2014 to 2018), 394 samples (uterine swabs and lavages) obtained from mares before breeding, regardless of clinical history of endometritis were analyzed. Our bacteriological procedure included the subculturing from the enrichment in Brain Heart Infusion Broth of the samples resulted negative after direct smearing. A total of 386 microorganisms were isolated from 230 positive samples (58%). At least one microorganism was isolated from 33% of the samples after direct smearing and from another 25% after enrichment. The results, obtained from both direct smearing and enrichment, also show a significative difference between positive uterine lavages (80%) and swabs (53%). The most frequently isolated bacteria were α-haemolytic Streptococcus (27%), Escherichia coli (27%), ß-haemolytic Streptococcus (26.1%) and Staphylococcus spp. (19.1%). In monoculture, the most common isolated microorganisms were α-haemolytic Streptococcus (13%), Staphylococcus spp. (12.2%), ß-haemolytic Streptococcus (11.4%) and Escherichia coli (9.8%). Focusing on the samples with a pure culture, Gram-negative bacteria grew preferably after direct smearing, while Gram-positive after enrichment. In conclusion, the present study shows that uterine lavage with high volume of fluid statistically significantly increased the sensitivity of the bacteriological examination and highlights the key role of the enrichment step in the routine bacteriological laboratory procedure by increasing the isolation rate.

Current findings in endometrial microbiome: impact on uterine diseases.

Microbiome or microbiota is essential to regulate many mammalian physiological processes, including reproduction. Like other organs or tissues, the upper female reproductive tract used to be considered as devoid of microorganisms; however, a non-infection-related bacterial community was discovered in the uterus from humans and other mammals, and its composition is related to reproductive success. The dysbiosis of endometrial microbiota is associated with benign and malign uterine diseases. Hence, this review addressed the current knowledge about uterine microbiota alterations and their association with common endometrial diseases, including endometrial polyposis, endometriosis, uterine myomatosis, endometrial hyperplasia, and endometrial cancer. There is a specific bacterial community in the endometrium in the most-analyzed uterine diseases. However, the constant finding consists in a reduced abundance of Firmicutes and Lactobacillus, while there is an increased abundance of Proteobacteria (such as Escherichia coli and Enterococcus), Bacteroidetes (Prevotella, for example), and Actinobacteria (as Gardnerella), in contrast to healthy endometrium. Besides, we discussed the future usefulness of the endometrial microbiota components as biomarkers to diagnose uterine diseases and their probable clinical outcomes. In addition, we analyzed their potential use as probiotics since they could provide an alternative or complement to existing therapies.

Characterization of microbial communities and predicted metabolic pathways in the uterus of healthy mares.

Background: Culture-independent techniques have made it possible to expand the knowledge about the composition of bacterial communities present in the healthy uterus and their role in health and disease, mainly in humans. However, in animals like mares, there is a dearth of information regarding this area. Aim: To narrow this knowledge gap, the objective of this study was to identify and characterize the composition and function of the uterine microbiome of a group of Chilean purebred mares (CPM), an equine breed with the oldest genealogical record in South America and an economical important reproductive industry. Methods: From uterine biopsy samples obtained during estrus, DNA extraction and targeted sequencing were performed to investigate the bacterial diversity and its probable metabolic function. Results: CPM biopsy samples were characterized by having a varied microbial composition, where the four most relatively abundant phyla were Proteobacteria (69.6%), Firmicutes (21.1%), Bacteroidetes (7.8%), and Actinobacteria (1.06%); which made up 99.6% of the total identified phyla. In contrast, Actinobacteria and Fusobacteria were the phyla not identified in all samples. Of a total of 59 genera identified across all samples, Staphylococcus was the most abundant genus with an average relative abundance of 18.88%, followed by Pseudomonas (17.9%), Escherichia/Shigella (10.42%), and Klebsiella (9.92%). Conclusion: These findings contribute to the knowledge of microbes' presence in the uterus, while future studies are required to demonstrate the role of these microorganisms in health and disease.

The function and mechanism of action of uterine microecology in pregnancy immunity and its complications.

The human microbiota influences physiology, disease, and metabolic reproduction. The origin of uterine bacteria is controversial. The main assumption is that the germs enter the uterine cavity from the vagina through the cervical canal, bloodstream, fallopian tubes, and gynecological surgical channels. Understanding the microbiota at various anatomical sites is critical to the female reproductive system and pregnancy. Today's study focuses on the role of uterine bacteria in pregnancy and embryo implantation. According to our findings, the uterine microbiome influences embryo implantation and pregnancy outcome. Pregnancy is a natural, evolutionarily selected approach to human reproduction. During pregnancy, the microbiota of the reproductive tract changes, facilitating the maintenance of pregnancy, and the human immune system undergoes a series of changes that recognize and adapt to the non-self. From the beginning of pregnancy, a non-self fetus must establish a placenta of embryonic origin to protect itself and promote growth; the VMB tends to be more stable and lactobacillus-dominated in late gestation than in early gestation. Any material that disrupts this connection, such as microbial changes, is associated with a higher risk of poor health and poor pregnancy outcomes in women (eclampsia). The presence of any material that disrupts this connection, such as microbial changes, is associated with a higher risk of poor health and poor pregnancy outcomes (preeclampsia, preterm birth, gestational diabetes, etc.). In this work, we review the last decade of relevant research to improve our understanding of the mechanisms by which the microbiota of the female reproductive tract influences female reproductive health. This work discusses the mechanisms associated with the reproductive tract microbiota and pregnancy immunity, as well as the impact of an abnormal microbiota on adverse pregnancy outcomes. Emphasis is placed on the characteristics and sources of the female vaginal, uterine, and placental microbiota and the importance of a well-stabilized local human microbiota and immune system for embryo implantation, placental development, fetal growth, and pregnancy outcome.

Ascension of Chlamydia is moderated by uterine peristalsis and the neutrophil response to infection.

Chlamydia trachomatis is a common sexually transmitted infection that is associated with a range of serious reproductive tract sequelae including in women Pelvic Inflammatory Disease (PID), tubal factor infertility, and ectopic pregnancy. Ascension of the pathogen beyond the cervix and into the upper reproductive tract is thought to be necessary for these pathologies. However, Chlamydia trachomatis does not encode a mechanism for movement on its genome, and so the processes that facilitate ascension have not been elucidated. Here, we evaluate the factors that may influence chlamydial ascension in women. We constructed a mathematical model based on a set of stochastic dynamics to elucidate the moderating factors that might influence ascension of infections in the first month of an infection. In the simulations conducted from the stochastic model, 36% of infections ascended, but only 9% had more than 1000 bacteria ascend. The results of the simulations indicated that infectious load and the peristaltic contractions moderate ascension and are inter-related in impact. Smaller initial loads were much more likely to ascend. Ascension was found to be dependent on the neutrophil response. Overall, our results indicate that infectious load, menstrual cycle timing, and the neutrophil response are critical factors in chlamydial ascension in women.

Bovine Genital Leptospirosis and reproductive disorders of live subfertile cows under field conditions.

Bovine genital leptospirosis (BGL) is characterized by silent chronic reproductive disorders, most related to early embryonic death leading to estrus repetition, subfertility and abortions. However, most studies were conducted in slaughterhouses, which lacks reproductive and sanitary history of the studied animals. This study aimed to evaluate the occurrence of Leptospira sp. infection in live cows with history of low reproductive efficiency. Blood, urine, cervico-vaginal mucus and uterine fragment were collected from nine cows of the same herd presenting reproductive failure (abortions, estrus repetition and chronic infertility). Serology (MAT) and molecular analysis (PCR and nucleotide sequencing) were performed. Serology showed three (33.3%) seroreactive cows, two to Sejroe and one to Icterohaemorrhagiae serogroups. Six cows (66.7%) presented leptospiral DNA on genital samples, while all urine samples were negative. L. interrogans was identified in five samples, very closely related to strains from Sejroe (n = 3) and Icterohaemorrhagiae (n = 2) serogroups, while L. noguchii was identified in one sample. Results from this preliminary study demonstrates the presence of leptospires on uterus and reinforces the negative impact of leptospiral infection on reproductive tract, highlighting its association with reproductive failures on live animals.

Levofloxacin or gonadotropin releasing hormone agonist treatment decreases intrauterine microbial colonization in human endometriosis.

OBJECTIVE: We examined the hypothesis that antibiotic treatment with or without gonadotropin releasing hormone agonist (GnRHa) may decrease intrauterine infection with consequent decrease in tissue inflammation, cell proliferation and angiogenesis in human endometriosis. STUDY DESIGN: This is a prospective non-randomized observational study. Endometrial/endometriotic samples were collected during surgery from 53 women with endometriosis and 47 control women who were treated with levofloxacin (LVFX, 500 mg, once per os) or GnRHa (1.88 mg/IM for 3 months) before surgery. Endometrial samples were analyzed by broad-range polymerase-chain reaction (PCR) amplification of bacteria targeting V5-V6 region of 16S rRNA gene. Immunohistochemical analysis was performed using antibodies against CD138 (Syndecan-1, a marker of plasma cells), CD68 (marker of macrophages), Ki-67 (cell proliferation marker), and CD31 (vascular cells marker). RESULTS: 16S rDNA metagenome assay indicated that treatment with either of LVFX or GnRHa + LVFX significantly decreased some components of major bacterial genera comparing to untreated group. In women with endometriosis, treatment with either of LVFX or GnRHa + LVFX significantly decreased Gardnerella, Prevotella, Acidibactor, Atopobium, Megasphaera, and Bradyrhizobium (p < 0.05 for each) comparing to untreated group. Cochran-Mantel-Haenszel test indicated that occurrence rate of chronic endometritis was significantly decreased after GnRHa + LVFX treatment comparing to GnRHa treatment group (p = 0.041). These findings were coincided with significantly decreased CD68-stained macrophage infiltration, Ki-67- stained cell proliferation and CD31-stained micro-vessel density in endometria and endometriotic lesions with histology proven improvement in the morphological appearance of ovarian endometrioma. CONCLUSIONS: These findings suggest that clinical administration of a broad-spectrum antibiotic with or without GnRHa may be effective in improving uterine infection with decrease of tissue inflammation, cell proliferation, and angiogenesis in human endometriosis.

Reduced Uterine Tissue Damage during Chlamydia muridarum Infection in TREM-1,3-Deficient Mice.

Genital infections with Chlamydia trachomatis can lead to uterine and oviduct tissue damage in the female reproductive tract. Neutrophils are strongly associated with tissue damage during chlamydial infection, while an adaptive CD4 T cell response is necessary to combat infection. Activation of triggering receptor expressed on myeloid cells-1 (TREM-1) on neutrophils has previously been shown to induce and/or enhance degranulation synergistically with Toll-like receptor (TLR) signaling. Additionally, TREM-1 can promote neutrophil transepithelial migration. In this study, we sought to determine the contribution of TREM-1,3 to immunopathology in the female mouse genital tract during Chlamydia muridarum infection. Relative to control mice, trem1,3-/- mice had no difference in chlamydial burden or duration of lower-genital-tract infection. We also observed a similar incidence of hydrosalpinx 45 days postinfection in trem1,3-/- compared to wild-type (WT) mice. However, compared to WT mice, trem1,3-/- mice developed significantly fewer hydrometra in uterine horns. Early in infection, trem1,3-/- mice displayed a notable decrease in the number of uterine glands containing polymorphonuclear cells and uterine horn lumens had fewer neutrophils, with increased granulocyte colony-stimulating factor (G-CSF). trem1,3-/- mice also had reduced erosion of the luminal epithelium. These data indicate that TREM-1,3 contributes to transepithelial neutrophil migration in the uterus and uterine glands, promoting the occurrence of hydrometra in infected mice.

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.

Using PacBio sequencing to investigate the effects of treatment with lactic acid bacteria or antibiotics on cow endometritis

BACKGROUND: Endometritis is the most common disease of dairy cows and traditionally treated with antibiotics. Lactic acid bacteria can inhibit the growth of pathogens and also have potential for treatment of endometritis. Using PacBio single-molecule real-time sequencing technology, we sequenced the fulllength l6S rRNA of the microbiota in uterine mucus samples from 31 cows with endometritis, treated with lactic acid bacteria (experimental [E] group) and antibiotics (control [C] group) separately. Microbiota profiles taken before and after treatment were compared. RESULTS: After both treatments, bacterial species richness was significantly higher than before, but there was no significant difference in bacterial diversity. Abundance of some bacteria increased after both lactic acid bacteria and antibiotic treatment: Lactobacillus helveticus, Lactococcus lactis, Lactococcus raffinolactis, Pseudomonas alcaligenes and Pseudomonas veronii. The bacterial species that significantly decreased in abundance varied depending on whether the cows had been treated with lactic acid bacteria or antibiotics. Abundance of Staphylococcus equorum and Treponema brennaborense increased after lactic acid bacteria treatment but decreased after antibiotic treatment. According to COG-based functional metagenomic predictions, 384 functional proteins were significantly differently expressed after treatment. E and C group protein expression pathways were significantly higher than before treatment (p < 0.05). CONCLUSIONS: In this study, we found that lactic acid bacteria could cure endometritis and restore a normal physiological state, while avoiding the disadvantages of antibiotic treatment, such as the reductions in abundance of beneficial microbiota. This suggests that lactic acid bacteria treatment has potential as an alternative to antibiotics in the treatment of endometritis in cattle.

Changes in the Distribution of Intrauterine Microbiota May Attribute to Immune Imbalance in the CBA/J×DBA/2 Abortion-Prone Mice Model.

Background: Female Genital Tract (FGT) is an important micro-ecological area of human body. Microbiota in the lower reproductive tract may subsequently invade the uterine cavity during embryo implantation and produce immune responses. CBA/J×DBA/2 mating combination has been widely used as an abortion-prone mice model but whether microbiota existed in their uterine cavity remains unclear. In this context, the role of the microbial communities in immune response deserves attention. Objective: To investigate the relationship between the distribution of microbiota in the uterine cavity of CBA/J×DBA/2 abortion-prone mouse model and the immune imbalance of the maternal-fetal interface. Methods: In this study, female CBA/J mice were paired with male DBA/2 mice to develop an abortion-prone model (BA group), and with male BALB/c mice to build a standard pregnancy model (BC group). The non-pregnant female mice were served as the control group (C group). Uterine flushing fluid and sera were collected on day 13.5 of pregnancy. 16S rRNA sequencing technology was used to analyze the distribution of intrauterine microbiota. Phylogenetic Investigation of Communities were conducted to predict the microbiota functions by Reconstruction of Unobserved States (PICRUST) and Kyoto Encyclopedia of Genes and Genomes (KEGG). The serum IL 10, INF-γ, and TNF-α levels were examined using Enzyme-linked immunosorbent assay (ELISA) method. Results: All samples were detected with microbial communities. The α diversity (p = 0.00077) had significant differences among three groups. Proteobacteria was the most dominant phylum in C group (mean = 83.21%) and BA group (mean = 43.23%). Firmicutes was dominant in BC group (mean = 46.4%), as well as the second dominant one in C group (mean = 12.63%) and BA group (mean = 40.55%). Microbiota functions were associated with metabolism and immune response through the NOD-like receptor signaling pathway. The serum IL 10 level in BA group were significantly lower than that in BC group (10.14 ± 1.90 pg/ml, n = 8; vs. 19.03 ± 1.82 pg/ml, n = 10; p = 0.004). The serum TNF-α and INF-γ level in BA group were also significantly higher than that in BC group (523.1 ± 58.14 pg/ml, n = 8 vs. 310.3 ± 28.51 pg/ml, n = 10, p = 0.0029; 69.22 ± 5.38 pg/ml, n = 8 vs. 50.85 ± 2.45 pg/ml, n = 10, p = 0.0042). Conclusion: Microbial communities were colonized in uterine cavity of CBA/J mice both at non-pregnant stage and pregnant stage when mated with both BALB/c and DBA/2 male mice. The differentially abundant microbiome may be attributed to the immune tolerance through binding to the NOD-like receptor.

Effects of parity, blood progesterone, and non-steroidal anti-inflammatory treatment on the dynamics of the uterine microbiota of healthy postpartum dairy cows.

This study evaluated the effects of treatment with meloxicam (a non-steroidal anti-inflammatory drug), parity, and blood progesterone concentration on the dynamics of the uterine microbiota of 16 clinically healthy postpartum dairy cows. Seven primiparous and 9 multiparous postpartum Holstein cows either received meloxicam (0.5 mg/kg SC, n = 7 cows) once daily for 4 days (10 to 13 days in milk (DIM)) or were untreated (n = 9 cows). Endometrial cytology samples were collected by cytobrush at 10, 21, and 35 DIM, from which the microbiota analysis was conducted using 16S rRNA gene sequence analysis. A radioimmunoassay was used to measure progesterone concentration in blood serum samples at 35 DIM and cows were classified as ˃ 1 ng/mL (n = 10) or ≤ 1 ng/mL (n = 6). Alpha diversity for bacterial genera (Chao1, Shannon-Weiner, and Camargo's evenness indices) were not affected by DIM, meloxicam treatment, parity, or progesterone category. For beta diversity (genera level), principal coordinate analysis (Bray-Curtis) showed differences in microbiota between parity groups. At the phylum level, the relative abundance of Actinobacteria was greater in primiparous than multiparous cows. At the genus level, there was lesser relative abundance of Bifidobacterium, Lactobacillus, Neisseriaceae, Paracoccus, Staphylococcus, and Streptococcus and greater relative abundance of Bacillus and Fusobacterium in primiparous than multiparous cows. Bray-Curtis dissimilarity did not differ by DIM at sampling, meloxicam treatment, or progesterone category at 35 DIM. In conclusion, uterine bacterial composition was not different at 10, 21, or 35 DIM, and meloxicam treatment or progesterone category did not affect the uterine microbiota in clinically healthy postpartum dairy cows. Primiparous cows presented a different composition of uterine bacteria than multiparous cows. The differences in microbiota associated with parity might be attributable to changes that occur consequent to the first calving, but this hypothesis should be investigated further.

Characterization of microbes associated with cervico-vaginal adhesion in the reproductive system of camels (Camelus dromedaries).

Vaginal and cervical adhesions are severe long-standing reproductive disorder in dromedaries and consequently result in a high culling rate. This study was designed to compare the microbial communities of the vaginae, cervices, and uteri of normal (n = 10) camels versus camels suffering from cervico-vaginal adhesion (n = 23). Vaginal, cervical, and uterine swab samples were collected from control and affected animals. Furthermore, serum samples were obtained for serological testing of Chlamydiosis and Coxiellosis. For bacteriological and fungal examination, swab samples were plated on Columbia and Saboraud's dextrose agar, respectively. Polymerase chain reaction (PCR) assay was applied to samples expressed seropositive for Chlamydiosis. Vaginal swab bacterial cultures showed that the affected animals were significantly infected with Staphylococcus aureus (P = 0.0322, CI: 0.25-0.95) than the control, while mycological cultures showed that both control and affected animals were infected with Cryptococcus and Candida albicans. Corynebacterium spp. (22.7%), Pseudomonas spp. (4.5%), Klebsiella spp. (9.1%), T. pyogenes (18.2%), and anaerobic bacteria (Fusobacterium necrophorum and Clostridium spp.; 34.78%) were also identified in affected animals. Cervical samples from affected animals were distinguished by the existence of S. aureus (27.8%), Klebsiella spp. (5.6%), Corynebacterium spp. (22.2%), Cryptococcus (16.7%), Proteus spp. (11.1% (, T. pyogenes (11.1%), Pseudomonas spp. (5.6%), and Fusobacterium necrophorum (17.4%). Uterine samples from affected animals were characterized by the presence of S. aureus (22.2%), Streptococcus (22.2%), Corynebacterium spp. (11.1%), E. coli (11.1%), and Pseudomonas spp. (11.1%). Anaerobic bacteria were not isolated from control nor affected animals. Enzyme immunoassays revealed that 50% and 34.8% of the control and affected animals were positive for Coxiella burnetii, respectively, Chlamydia was detected in 43.5% of samples from affected animals, only 60% of which were confirmed positive. These results show that microbial communities linked with cervico-vaginal adhesion in dromedary camels are likely to be polymicrobial. The findings of this study are helpful in designing antimicrobial therapies toward reducing the incidence for cervico-vaginal adhesion.

A philosophical perspective on the prenatal in utero microbiome debate.

Within the last 6 years, a research field has emerged that focuses on the characterization of microbial communities in the prenatal intrauterine environment of humans and their putative role in human health. However, there is considerable controversy around the existence of such microbial populations. The often contentious debate is primarily focused on technical aspects of the research, such as difficulties to assure aseptic sampling and to differentiate legitimate signals in the data from contamination. Although such discussions are clearly important, we feel that the problems with the prenatal microbiome field go deeper. In this commentary, we apply a philosophical framework to evaluate the foundations, experimental approaches, and interpretations used by scientists on both sides of the debate. We argue that the evidence for a "sterile womb" is based on a scientific approach that aligns well with important principles of the philosophy of science as genuine tests of the hypothesis and multiple angles of explanatory considerations were applied. In contrast, research in support of the "in utero colonization hypothesis" is solely based on descriptive verifications that do not provide explanatory insight, which weakens the evidence for a prenatal intrauterine microbiome. We propose that a reflection on philosophical principles can inform not only the debate on the prenatal intrauterine microbiome but also other disciplines that attempt to study low-biomass microbial communities.