Actinobacillus seminis causes epididymitis in ruminants and spontaneous abortion. A. seminis virulence factors remain unknown; however, it has been shown that testosterone increased bacterial growth, adhesins expression, and protease expression, as well as biofilm production, suggesting the presence of a bacterial receptor for this hormone. The present study reported the isolation of two potential testosterone receptors from A. seminis grown in the presence of testosterone. A 75 kDa and a 55 kDa proteins were isolated from bacterial lysate with triazine orange-Sepharose CL6B column or with immobilized testosterone on polystyrene plates, respectively. Mass spectrometry identified the 75 kDa as the periplasmic LsrB, and the 55 kDa as the outer membrane OmpF from A. seminis. Molecular docking showed OmpF and LsrB interaction with testosterone in 59% and 55%, respectively. Testosterone plus furanone C-30 inhibits the expression of those proteins diminished bacterial growth, adhesin and protease expression. Cloning A. seminis lsrB into E. coli M15 strain improves clone development in a dose-dependent manner and induces the expression of proteases and putative adhesins. These findings strongly suggest that host testosterone could play a significant role in A. seminis pathogenesis, through OmpF and LsrB as testosterone receptors.

Gardnerella vaginalis is a key bacterium in the etiology of bacterial vaginosis (BV) and contributes to biofilm formation. Gardnerella is a facultative anaerobic bacterium, meaning it can grow both in the presence of oxygen and under anaerobic conditions. We conducted a prospective study in 2025, including 160 consecutive vaginal samples from women submitted for pathogenic bacteria. Clinical information on the referral form indicated in 87 women (54.4%), from which colpitis in 64 cases (73.6%). There were 43 pregnant women (26.9%), with an average age of 30.7 years. Each vaginal sample was cultured on Gardnerella agar and incubated in both CO2 and anaerobic atmospheres. The culture plates were examined after 24 and 48 h of incubation, independently of other results. In cases where suspicious colonies with beta-hemolysis were observed, bacterial identification was performed using MALDI-TOF mass spectrometry (Bruker). Gram-stained smears were evaluated according to the Nugent score. The bacteria Gardnerella vaginalis and Gardnerella leopoldii/swidsinskii were detected in 46 (28.8%) samples. The sensitivity of G. vaginalis and G. leopoldii/swidsinskii cultivation on Gardnerella agar in a CO2 atmosphere was 67.4% compared to anaerobic cultivation. Anaerobic cultivation on Gardnerella agar proved to be a superior method for the isolation of G. vaginalis and G. leopoldii/swidsinskii compared to cultivation in a CO2 atmosphere. The diagnosis of BV in clinical practice relies on standard Amsel's criteria, gram-stained vaginal smears evaluated using the Nugent scoring system or Ison-Hay criteria, and the isolation of G. vaginalis and G. leopoldii/swidsinskii.IMPORTANCEBacterial vaginosis (BV) is the most common vaginal infection among women of reproductive age and is associated with significant adverse outcomes, including preterm birth, spontaneous abortion, and increased susceptibility to sexually transmitted infections. Accurate and timely microbiological diagnosis is therefore clinically important. Our study demonstrates that anaerobic incubation on selective Gardnerella agar improves the detection of Gardnerella vaginalis and Gardnerella leopoldii/swidsinskii compared with incubation in a CO2-enriched atmosphere. Under anaerobic conditions, colonies were larger, hemolysis was more pronounced, and overall sensitivity was higher. Although BV diagnosis in clinical practice primarily relies on Amsel's criteria and Nugent scoring, optimized culture conditions provide valuable complementary microbiological evidence. These findings contribute to the optimization of laboratory procedures and may enhance the reliability of routine diagnostic workflows in women with suspected BV.

Pregnancy-related disorders, including preterm birth, preeclampsia, recurrent spontaneous abortion, and fetal growth restriction, represent major contributors to global maternal and infant morbidity and mortality. Their pathophysiology involves complex mechanisms such as immune dysregulation, inflammatory responses, oxidative stress, and metabolic disturbances. Interferon-stimulated gene 15 (ISG15), a ubiquitin-like protein, regulates diverse biological processes-including antiviral immunity, cellular metabolism, oxidative stress, and DNA damage response-through ISGylation, which covalently conjugates ISG15 to target proteins. In recent years, the potential role of ISG15 in pregnancy-related diseases has attracted growing interest. This review systematically outlines the molecular characteristics and functions of ISG15, with a focus on its research advances in preeclampsia, recurrent spontaneous abortion, preterm birth, and fetal growth restriction. Furthermore, it discusses the potential of ISG15 as a novel biomarker or therapeutic target for pregnancy-related disorders, providing new insights for early prevention and clinical management. Collectively, this review positions ISG15 as a critical regulator in pregnancy-related pathologies and underscores its translational potential.

Early pregnancy loss (EPL) is a common complication with incompletely understood pathogenesis. Recent studies highlight the roles of exosomes and their miRNAs in intercellular communication, and the influence of uterine decidual microbiota on pregnancy outcomes. This study aimed to characterize decidual exosomes and microbiota in EPL patients and explore their mechanistic roles in EPL development. Exosomes were extracted from decidual tissues of women undergoing normal pregnancy termination (NC group) and those with early pregnancy embryonic loss (EPL group). These exosomes were applied to treat trophoblast cells (HTR8/SVneo), and cell functions were examined using CCK-8, Transwell assays, and Annexin V-PI staining. Inflammation-related gene expression was quantified by qRT-PCR. Microarray analysis identified differentially expressed exosomal miRNAs, validated by qRT-PCR. 16S rRNA sequencing analyzed microbial community differences between groups, with key taxa identified using LEfSe. The roles of miR-483-5p mimics on Lactobacillales and trophoblast cells were also examined. Exosomes from both groups expressed CD63, HSP70, and Histone-H3, with typical membrane structures observed and particle sizes of 100-120 nm. Exosomes from the EPL group remarkably repressed trophoblast cell proliferation, migration, and invasion, promoted apoptosis, and upregulated TLR4, NF-κB, IL-6, TNF-α, and IL-8 mRNA levels. Microarray analysis revealed significant downregulation of miR-483-5p in exosomes from the EPL group. 16S rRNA sequencing showed distinct microbial communities in decidual tissues of the EPL group, particularly in Lactobacillales and Erysipelotrichaceae abundance. Hsa-miR-483-5p mimics enhanced Lactobacillales viability and colocalized with them. Combined treatment with miR-483-5p mimics and Lactobacillales reversed the inhibitory effects of exosomes from the EPL group on trophoblast cells and downregulated inflammatory factor expression. This study characterized exosomes in the decidual tissues of the EPL group and their inhibitory effects on trophoblast cells, identifying key miRNAs (miR-483-5p) and microbial taxa (Lactobacillales). These results indicate that exosomes and microbiota could play a role in EPL development by regulating trophoblast functions and inflammatory responses.

Background: Early pregnancy loss, defined as the spontaneous loss of a pregnancy before 20 weeks of gestation or when the fetus weighs less than 500 g, remains a common obstetric complication, affecting up to 15% of clinically recognized pregnancies. Chromosomal abnormalities, particularly aneuploidies such as trisomies and monosomy X, account for 50-60% of first-trimester losses, with incidence increasing alongside maternal age. Additional risk factors include maternal medical conditions, uterine anomalies, infections, and modifiable lifestyle factors. Pregnancies conceived through assisted reproductive technologies also carry a slightly higher risk of miscarriage, often influenced by maternal age and embryo quality. Methods: Two pathologists, blinded to each other's assessments, analyzed abortive material from patients who experienced spontaneous first-trimester abortion between January 2012 and January 2025 at Agostino Gemelli Hospital, Rome, Italy. Inclusion criteria were defined independently of patient demographics. No restrictions were applied regarding maternal age. With respect to gestational age, only first-trimester miscarriages (≤12 weeks of gestation) were considered. In cases of discordance, the case was reviewed and re-evaluated to reach a final diagnosis. Results: The findings of this study are presented as a proposed histopathological classification and diagnostic framework for first-trimester miscarriages. Specifically, a total of 1168 cases were categorized into eight distinct groups of miscarriage etiology based exclusively on the histomorphological features of chorionic villi and maternal decidua. Conclusions: Histopathological examination of products of conception is essential for confirming intrauterine pregnancy, identifying underlying maternal or fetal causes, and guiding future reproductive management, particularly in recurrent pregnancy loss. This study evaluates histopathological features of first-trimester losses, classifies findings by etiology, and proposes a practical diagnostic guide to support clinical decision-making and improve outcomes in subsequent pregnancies.

The risk of placenta accreta spectrum (PAS) associated with in vitro fertilization and embryo transfer (IVF-ET) in the context of mid-trimester pregnancy loss remains unclear. This study aimed to investigate the impact of IVF-ET on the incidence of PAS and identify the risk factors among women undergoing pregnancy loss following fetal demise or inevitable miscarriage during the second trimester. In our retrospective cohort study, we analyzed women who experienced second-trimester fetal loss due to fetal demise or inevitable miscarriage at the Sixth Affiliated Hospital of Sun Yat-sen University between January 2013 and October 2023. The participants were categorized into IVF-ET (n = 93) and non-IVF-ET (n = 134) groups. The primary outcome was the incidence of PAS, which was diagnosed clinically or pathologically. Secondary outcomes included morbid PAS, postpartum hemorrhage, and other complications. Our results indicated that the IVF-ET group had a significantly greater risk of experiencing PAS (39.8% vs 17.9%, P < .001) and morbid PAS (17.2% vs 3.7%, P < .001) compared to the non-IVF-ET group. The median postpartum blood loss was greater (230.0 [120.0-600.0] mL vs 120.0 [70.0-200.0] mL, P < .001), and the rates of postpartum hemorrhage (30.1% vs 12.7%, P = .001) and retained products of conception persisting >4 weeks (38.7% vs 19.4%, P < .001) were also greater in the IVF-ET group. Multivariate analysis revealed IVF-ET (adjusted odds ratio [aOR] = 3.13; P = .002), a hysteroscopic history (aOR = 3.58; P = .02), and uterine abnormalities (aOR = 3.74; P = .02) as independent risk factors for PAS. In the IVF-ET group, compared with fresh embryo transfer, cryopreserved embryo transfer (aOR = 3.52; P = .01) was associated with a markedly higher risk of PAS (50.9% vs 22.2%, P = .006) and remained an independent risk factor after adjustment (aOR = 3.52; P = .01). Among women with mid-trimester pregnancy loss, those who underwent IVF-ET, especially cryopreserved embryo transfer, had a high risk of PAS, leading to increased hemorrhagic morbidity and complications. These findings highlight the need for enhanced preoperative assessment, vigilant management, and strategies to preserve fertility in this high-risk population.