Pathogenic mechanism, detection methods and clinical significance of group B Streptococcus

Loratadine Derivative Lo-7: A Weapon against Drug-Resistant Enterococcus and Streptococcal Infections

The primary obstacles in the management of Enterococcus and Streptococcal infections are drug resistance and biofilm formation. Our study revealed that loratadine at a concentration of ≥25 μM exhibited significant inhibitory effects on biofilm formation in 167 clinical strains of Enterococcus faecalis and 15 clinical isolates of Streptococcus agalactiae, Streptococcus pyogenes, and Streptococcus pneumoniae. Additionally, the antibiofilm activity against E. faecalis and Streptococcal was demonstrated by several loratadine derivatives with altered side-chain carbamate moieties. This study investigated the antibacterial activity of the loratadine derivative Lo-7 against clinical strains of S. agalactiae and S. pyogenes, with minimum inhibitory concentrations ranging from 12.5 to 25 μM. The findings revealed that a low concentration of loratadine derivative Lo-7 (3.125 μM) significantly augmented the bactericidal efficacy of vancomycin against multidrug-resistant (MDR) S. agalactiae, both in vitro and in vivo. The loratadine derivative Lo-7, even at low concentrations, demonstrated significant efficacy in eliminating intracellular MDR S. agalactiae within macrophages, potentially indicating a unique advantage over vancomycin, linezolid, and loratadine. Mechanistically, exposure to the loratadine derivative Lo-7 resulted in membrane depolarization without affecting membrane permeability in S. agalactiae. The potential targeting of the SecG subunit of the SecYEG membrane-embedded channel by the loratadine derivative Lo-7 in S. agalactiae was identified through quantitative proteomics, a drug affinity responsive target stability assay, and molecular docking.

Menstrual Blood as a Diagnostic Specimen for Human Papillomavirus Genotyping and Genital Tract Infection Using Next-Generation Sequencing as a Novel Diagnostic Tool

BACKGROUND

Menstrual blood (MB) is a convenient specimen type that can be self-collected easily and non-invasively by women. This study assessed the potential application of MB as a diagnostic specimen to detect genital tract infections (GTIs) and human papillomavirus (HPV) infections in women.

METHOD

Genomic DNA was extracted from MB samples. Pacific Bioscience (Pacbio) 16S ribosomal DNA (rDNA) high-fidelity (HiFi) long-read sequencing and HPV PCR were performed.

RESULTS

MB samples were collected from women with a pathological diagnosis of CIN1, CIN2, CIN3 or HPV infection. The sensitivity and positive predictive value (PPV) of high-risk HPV detection using MB were found to be 66.7%. A shift in vaginal flora and a significant depletion in Lactobacillus spp. in the vaginal microbiota communities were observed in the MB samples using 16S rDNA sequencing.

CONCLUSIONS

In this study, we demonstrated that MB is a proper diagnostic specimen of consideration for non-invasive detection of HPV DNA and genotyping using PCR and the diagnosis of GTIs using metagenomic next-generation sequencing (mNGS). MB testing is suitable for all women who menstruate and this study has opened up the possibility of the use of MB as a diagnostic specimen to maintain women's health.

Establishment and application of a rapid molecular diagnostic platform for the isothermal visual amplification of group B Streptococcus based on recombinase polymerase

With growing concerns about Group B streptococcal (GBS) infections and their adverse effects on perinatal pregnancies, including infection, premature delivery, neonatal septicemia, and meningitis, it is urgent to promote GBS screening at all pregnancy stages. The purpose of this study is to establish a device-independent, fast, sensitive, and visual GBS detection method. Taking advantage of the characteristics of the recombinase polymerase isothermal amplification (RPA), the activity of the nfo nuclease cleavage base analog (tetrahydrofuran, THF) site, and the advantages of visual reading of the lateral flow chromatography strip (LFS), a GBS detection method was developed. This method focused on the conservative region of the Christie-Atkins-Munch-Petersen factor encoded by the cfb gene, a virulence gene specific to GBS. Two forward primers, two biotin-labeled reverse primers, and one fluorescein isothiocyanate (FITC)-labeled and C3spacer-blocked probe were designed. The study involved optimizing the primer pair and probe combination, determining the optimal reaction temperature and time, evaluating specificity, analyzing detection limits, and testing the method on 87 vaginal swabs from perinatal pregnant women. The results showed that the visual detection method of GBS-RPA-LFS, using the cfb-F1/R2/P1 primer probe, could detect GBS within 15 min at the temperature ranging from 39°C to 42°C. Furthermore, the method specifically amplified only GBS, without cross-reacting with pathogens like Lactobacillus iners, Lactobacillus crispatus, Candida albicans, Listeria monocytogenes, Yersinia enterocolitica, Klebsiella Pneumoniae, Enterobacter cloacae, Citrobacter freundii, Vibrio alginolyticus, Vibrio parahaemolyticus, Salmonella typhimurium, Staphylococcus aureus, Pseudomonas aeruginosa, or Trichomonas vaginalis. It could detect a minimum of 100 copies per reaction. In clinical 98 samples of vaginal swabs from pregnant women, the agreement rate between the GBS-RPA-LFS method and TaqMan real-time fluorescence quantification method was 95.92%. In conclusion, this study successfully established a combined RPA and LFS GBS in situ detection platform, with short reaction time, high sensitivity, high specificity, portability, and device independence, providing a feasible strategy for clinical GBS screening.

Zinc Oxide Quantum Dots May Provide a Novel Potential Treatment for Antibiotic-Resistant Streptococcus agalactiae in Lama glama

Streptococcus agalactiae is a significant pathogen that can affect both human beings and animals. The extensive current use of antibiotics has resulted in antibiotic resistance. In our previous research, we found that zinc oxide quantum dots (ZnO QDs) had inhibitory effects on antibiotic-resistant microorganisms. In this study, a strain of Streptococcus agalactiaeWJYT1 with a broad antibiotic-resistant spectrum was isolated and identified from Lama glama at Sichuan Agricultural University Teaching Animal Hospital. The genome for the resistance and virulence genes was analyzed. Additionally, the antibacterial effects and anti-virulence mechanism of ZnO QDs for S. agalactiaeWJYT1 were investigated. The results showed that the genome of S. agalactiaeWJYT1 is 1,943,955 bp, containing 22 resistance genes and 95 virulence genes. ZnO QDs have a good antibacterial effect against S. agalactiaeWJYT1 by reducing bacterial growth and decreasing the expression of virulence genes, including bibA, hylB, sip, and cip, which provides a novel potential treatment for S. agalactiae.

Vaginal microbiome and cervical cancer

The female reproductive tract, similar to other mucosal sites, harbors a specific microbiome commonly dominated by Lactobacillus species (spp.), which has an essential role in maintaining health and homeostasis. Increasing evidence shows that genital tract dysbiosis and/or specific bacteria and cytokines might have an active role in the development and/or progression of HPV infection and cervical intra-epithelial neoplasia (CIN) and as a result cervical cancer. Cross-sectional and longitudinal studies reported that Lactobacillus spp. depletion increases with severity of CIN and that this may negatively affect disease regression rates. It is plausible that Lactobacillus deplete microbiome composition may lead to a pro-inflammatory environment that can increase malignant cell proliferation and HPV E6 and E7 oncogene expression. Future longitudinal cohorts and mechanistic experiments on HPV transfected cells models will further permit exploration of the impact of Lactobacillus spp. on HPV infection.

Implications of Gut Microbiota in Epithelial-Mesenchymal Transition and Cancer Progression: A Concise Review

Advancement in the development of molecular sequencing platforms has identified infectious bacteria or viruses that trigger the dysregulation of a set of genes inducing the epithelial-mesenchymal transition (EMT) event. EMT is essential for embryogenesis, wound repair, and organ development; meanwhile, during carcinogenesis, initiation of the EMT can promote cancer progression and metastasis. Recent studies have reported that interactions between the host and dysbiotic microbiota in different tissues and organs, such as the oral and nasal cavities, esophagus, stomach, gut, skin, and the reproductive tract, may provoke EMT. On the other hand, it is revealed that certain microorganisms display a protective role against cancer growth, indicative of possible therapeutic function. In this review, we summarize recent findings elucidating the underlying mechanisms of pathogenic microorganisms, especially the microbiota, in eliciting crucial regulator genes that induce EMT. Such an approach may help explain cancer progression and pave the way for developing novel preventive and therapeutic strategies.