Since its creation in 2013, Professor Baud's research team has been studying emerging infections in the Gynecology and Obstetrics field. Thanks to the expertise in maternal-fetal medicine and medical microbiology, along with precious local collaborations (Institute of Microbiology, Clinical Pharmacy, Neurosciences, Forensic Medicine, Infectious Disease - Travel Medicine), several clinical and basic research projects are conducted within the group.
Recently, the group has been very active in the investigation of the impact of Zika virus on pregnancy, during the recent epidemics. Various collaborations with the most affected countries led to an international recognition of this Lausanne research, crowned by publications in The Lancet, The Lancet Infectious Disease and BMJ.
Perinatal viral infections might impact the correct fetal development, leaving important consequences after birth. This is the case for well-known pathogens, like in the case of cytomegalovirus, and emergent pathogens like Zika virus. It is of crucial importance to study the pathogenesis and epidemiology of such viruses in order to envision effective measures to protect both the mothers and their children.
Our group is investigating specifically adverse effect of viral infections on the development of the fetal brain, by using an in vitro model of human neural progenitor cells.
In addition, our research group has put much effort on the development of an international Zika registry, with the goal to allow researchers to quantitatively estimate the risks, identify specific risk factors, better characterise the spectrum of disease and propose adequate prevention measures and clinical management strategies for exposed pregnancies and infected neonates.
A healthy urogenital tract is required for adequate sperm production and function in order to allow normal fertility. There is substantial evidence that bacterial infections of the male genital tract are associated with infertility. Pathogenic bacteria may impair fertility at several levels including inflammation, epididymitis, orchitis, obstruction of reproductive tracts and spermatozoa damage.
In the laboratory, we use an in vitro model of infection to study the impact of bacteria on spermatozoa physiology, by measuring several parameters, including viability, mitochondrial membrane potential, DNA fragmentation and motility. This allowed us to discover a negative effect of W. chondrophila (see below) on human spermatozoa and will be exploited in the future for other bacteria.
Presence of bacteria in the semen (bacteriospermia) is, however, not always associated with a pathological. Recent studies indicate that identification of bacteria in semen is frequent, including in fertile individuals with normal sperm. Consequently, as with other sites of the human body, it appears that semen has a specific microbiota. The majority of studies have focused on bacterial communities of gut and skin, which represent the main sites of colonization in the body. Nevertheless, importance of other microbial communities has been highlighted, including the vaginal microbiota.
We are currently analysing the bacterial content of men from couples with infertility issues.
Infertility affects one in seven couples and a specific cause is identified in only 50%. Although lifestyle and environmental factors have been proposed for idiopathic male infertility, no clear etiology has been identified. Bacterial infection or colonization might impair fertility potential.
By combining analyses of genital bacterial carriage of both partners of couples with fertility issues (inability to conceive >1 year), we aim at identifying specific bacterial signatures associated with their clinical and fertility conditions. Moreover, we want to explore what is the role of genital microbiota on the fertility treatment outcome.
Spontaneous preterm birth (PTB), defined as birth at <37 weeks of gestation, is a major health problem, with rates currently reaching >10% of all deliveries. PTB is the leading cause of neonatal mortality and morbidity. Specific vaginal floras have been associated with increased risk of PTB, while others showed a protective role.
Our laboratory is exploring the vaginal microbial content of women experiencing PTB, in order to compare it with the microbiota of women delivering at term. In addition, we are evaluating the impact of maternal colonization on newborn health.
Waddlia chondrophila, an emerging pathogen associated with miscarriages
Approximately 25% of women will experience at least one miscarriage during their life. Despite a large number of possible investigations, a cause of the miscarriage is identified in less than 50% of the cases. Intracellular bacteria, which are not routinely investigated in clinical practice, might represent possible agents of miscarriages of unknown etiology. Listeria monocytogenes, Chlamydia trachomatis and Coxiella burnetii are known intracellular bacteria associated with adverse pregnancy outcome. Recently, several studies identified Waddlia chondrophila, an emerging intracellular bacterium belonging to the order of Chlamydiales, to be strongly associated with adverse pregnancy outcomes both in women and animals. W. chondrophila positive serologies as well as PCR and immunohistochemistry (both in the genital tract and placenta) were more likely to be present in women with miscarriages.
Our group is currently investigating:
C. trachomatis is the most commonly reported sexually transmitted bacterial infection worldwide, with more than 100 million new cases annually, 90% being asymptomatic. However, infection may translate into significant complications such as miscarriage, preterm birth, neonatal pneumonia, tubal infertility, ectopic pregnancy, pelvic inflammatory disease (PID), blindness and urethritis.
Our group is currently focused on the initial steps of chlamydial infection, which, despite the notoriety of this bacterium, remains understudied. Our main goal is to identify all the cellular receptors exploited by this pathogen to penetrate into host cells.