Risk of contamination of semen, vaginal secretions, follicular fluid and ovarian medulla with SARS-CoV-2 in patients undergoing ART.

STUDY QUESTION: Can severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) mRNA be detected in the reproductive tract of asymptomatic patients undergoing ART? SUMMARY ANSWER: SARS-CoV-2 mRNA is not detectable in semen, follicular fluid, vaginal secretions or residual medulla from ovarian tissue cryopreservation procedures in asymptomatic patients who undergo ART, irrespective of the results of a triage questionnaire and a nasopharyngeal SARS-CoV-2 RNA detection test. WHAT IS KNOWN ALREADY: The SARS-CoV-2 pandemic had a huge impact on the activities of fertility clinics. Although some studies reported the presence of SARS-CoV-2 mRNA in the reproductive system during or after acute COVID-19 symptomatic infections, uncertainties remain regarding the presence of viral mRNA in the reproductive material and follicular fluid of asymptomatic patients undergoing ART. STUDY DESIGN, SIZE, DURATION: An observational cohort trial of residual material samples including semen, follicular fluid, vaginal secretions and ovarian medulla was conducted during the second pandemic wave in Brussels from September 2020 to April 2021. PARTICIPANTS/MATERIALS, SETTING, METHODS: All patients who underwent ART (IUI, IVF/ICSI, oocyte and ovarian tissue cryopreservation) responded to a triage questionnaire at the beginning and end of the cycle and underwent nasopharyngeal swab collection for SARS-CoV-2 RNA detection by RT-PCR before the procedure according to standard recommendations. For semen analysis, only the questionnaire was requested the day before the sample collection. The ART cycles of patients with positive nasopharyngeal SARS-CoV-2 RNA detection tests and/or questionnaires were cancelled except for those that could not be postponed. After providing informed consent, swabs on residual materials were collected the day of the oocyte, ovarian tissue or semen collection and were processed for RT-qPCR. MAIN RESULTS AND THE ROLE OF CHANCE: A total of 394 samples from 291 patients were analysed. Amongst them, 20 samples were obtained from patients with a positive questionnaire but negative nasopharyngeal SARS-CoV-2 test and 20 others were from patients with a positive nasopharyngeal SARS-CoV-2 test. The remaining samples were collected from patients with a negative or unknown nasopharyngeal SARS-CoV-2 test and/or a negative or unknown triage questionnaire. Viral RNA for SARS-CoV-2 was undetectable in all of the samples. LIMITATIONS, REASONS FOR CAUTION: Considering the cancellation policy, only a limited number of samples from patients with positive triage questionnaires or nasopharyngeal SARS-CoV-2 tests were included in the analysis. WIDER IMPLICATIONS OF THE FINDINGS: The study suggested that there was no risk of reproductive tract contamination by SARS-CoV-2 in asymptomatic patients, irrespective of the results from a triage questionnaire or nasopharyngeal SARS-CoV-2 test. The results suggested that no additional measures to prevent staff or cross-patient contamination need to be implemented in the IVF and andrology laboratories. STUDY FUNDING/COMPETING INTEREST(S): This study was funded by the Université Libre de Bruxelles and by a grant from Ferring. A.D. and I.D. received a grant from Ferring for the study. The authors have no other conflict of interest to declare related to this study. TRIAL REGISTRATION NUMBER: N/A.

Updated emm-typing protocol for Streptococcus pyogenes.

OBJECTIVES: PCR-based typing of the emm gene Streptococcus pyogenes often results in the amplification of multiple bands. This has resulted in the misclassification of strains into types based on non-emm gene sequences. We aimed to improve the specificity of the emm typing PCR reaction using a primer called CDC3, the sequence for which has been previously used to identify emm genes in silico. METHODS: The proposed primer CDC3 was validated in silico from a global database of 1688 GAS genomes and in vitro with 32 isolates. PCR reactions were performed on genomic DNA from each isolate, using the published CDC1 forward primer with the CDC2 reverse primer or the new CDC3 reverse primer. The products were examined by gel electrophoresis, and representative PCR products were sequenced. RESULTS: In 1688 S. pyogenes genomes, the previous CDC2 reverse primer annealed in silico in 1671 emm genes and also in 2109 non emm genes in close proximity, whereas the new CDC3 primer annealed in 1669 emm genes only. The remaining 19 genes without a CDC3 binding site were chimeric emm genes. The PCR pair CDC1+CDC3 produced a single band at appropriate molecular weight in all 32 isolates tested, while the CDC1+CDC2 pair produced more than one band in 13 of 32 isolates (40%). CONCLUSIONS: The new CDC3 primer is more specific for emm genes than the previous CDC2 primer and represents a simple solution to reduce the potential for mistyping S. pyogenes strains.

H2O2, signal, substrate, mutagen and chemorepellent from physiology to biochemistry and disease.

The history of the study by our group of the generation, the role and the effects of H2O2 in the thyroid, is summarized. The relations with thyroid diseases are discussed: myxedematous cretinism, thyroiditis, thyroid cancer, congenital hypothyroiddism, are discussed. A new role of H2O2 in the chemorepulsion of bacteria is proposed.

Potential role of Noxes in the protection of mucosae: H(2)O(2) as a bacterial repellent.

Duox proteins are members of the NADPH oxidase (Nox) family and are responsible for hydrogen peroxide (H(2)O(2)) production by various tissue types including bronchial and intestinal mucosae. The antimicrobial killing role of H(2)O(2) in leukocytes and macrophages is generally considered as the paradigm of its function. We investigated here the positive role of H(2)O(2) in the prevention of cellular invasion by Salmonella. We show that H(2)O(2), under conditions that preserved bacterial growth, has a repellent effect on Salmonella motility on agar plates. In addition, H(2)O(2) produced by PCCl3, a rat thyroid cell line, reduces bacterial invasion of the cells by around 40%. To test whether the observed phenotype is attributable to H(2)O(2) production, we constructed a CHO stable cell line expressing Duox2 protein at the cell surface (CHO-D2). The transfected cells produce a high amount of H(2)O(2). Upon infection with Salmonella, the invasion of CHO-D2 cells was reduced by up to 60%. In both PCCl3 and CHO expressing Duox2 cells, normal invasion was restored upon incubation with catalase. Our data suggest that H(2)O(2) at reduced concentrations acts as a repellent for bacteria, keeping them away from cells, a situation that could naturally prevent mucosal cells infection in vivo.