Hannah Livingstone, a student in the Mucosal Infections Group working with VMRC4Africa, is dedicated to studying the vaginal microbiota and bacterial vaginosis (BV). With a keen interest in microbiome research and women’s health, Hannah’s work focuses on the complexities of BV and its treatment challenges.
What first drew you to the field of studying the vaginal microbiota and bacterial vaginosis (BV)?
I was always interested in microbiome research, and when the opportunity to study both women’s health and the microbiome came along, I knew it was right for me.
Why are current treatments for BV often ineffective, and what challenges do researchers face in developing more reliable treatments?
BV is interesting because it’s polymicrobial. So any treatment would have to target members of the non-optimal community while simultaneously promoting optimal community members. Balancing these two factors is challenging and is part of the reason we see so much BV recurrence.
Why did you choose to focus on Gardnerella species, and what makes these bacteria significant in the context of BV?
Gardnerella is one of the main genera associated with BV. In fact, there was discourse around whether or not Gardnerella was the sole causative agent of BV. While we are now aware that isn’t the case, the role of Gardnerella in BV is still considered pivotal. Research involving Gardnerella has also been really dynamic in recent years owing to the finding that it comprises several species and genomospecies – not a single member G. vaginalis. It’s a really exciting time to study Gardnerella.
Roughly how many different strains of this bacteria exist, and do they vary significantly worldwide and over time?
While I can’t give an estimate of how many strains there are, there are a minimum of 13 genomospecies. There are currently six species descriptions: G. vaginalis, G. leopoldii, G. swidsinskii, G. piotii, G. greenwoodii and G. pickettii.
Why is it important to research the strains of Gardnerella found in South Africa?
Microbiome research suggests that strains from different geographical locations vary from each other. This makes it critical to have geographically representative biorepositories to allow regionally relevant research to take place.
You were featured in FameLab for your work on Gardnerella vaginalis. Are you still busy with this or related research? How does your research tie into the VMRC4Africa project?
I am! The project has expanded but I’m still studying Gardnerella. This work is important for VMRC4Africa because it provides a panel of pathobionts which can be used to do preliminary screenings for activity of L. crispatus. Characterising Gardnerella spp is also important to understand interactions within the non-optimal community and the mechanisms these organisms use to cause disease.
Can you briefly explain how you’re going about studying the DNA of Gardnerella species? How will this help explain their behaviour and resistance to existing treatments?
I’ll be extracting DNA from strains I have isolated from South African women. This DNA will then be sequenced, and I will use bioinformatic tools to identify any genetic determinants of antimicrobial resistance and virulence factors. Since we have these isolates in a biorepository, I will then be able to ascertain whether we observe these characteristics in vitro.
Gardnerella evades treatment by forming a biofilm or bacterial barrier. Can you share more about this? Do Lactobacillus species exhibit similar behaviour?
Lactobacillus species also form biofilms. However this isn’t considered to be negative, as stable colonisation of species such as L. crispatus is critical for maintenance of an optimal vaginal microbiota. The recalcitrance of Gardnerella biofilms towards antibiotics makes BV treatment tricky and can lead to recurrence of BV symptoms.
You’re also studying co-occurrence patterns of Gardnerella in women with and without BV. Why is this important for understanding and treating BV?
Following the genus being split in 2019, there have been questions about how Gardnerella species interact with each other. What was considered to be a single species has been revealed to be a rather diverse group. This leads to a line of questioning as to how these groups interact with each other, how they co-occur and whether or not they contribute to BV differentially.
What have been some of the most significant findings so far?
One of the key findings of my project so far is that the majority of strains I have isolated show phenotypic resistance to metronidazole, the frontline treatment for BV. I have also built up a biorepository of strains including isolates of different Gardnerella species from a single individual and both metronidazole-resistant and susceptible isolates of the same species.
Based on your research, what potential strategies are emerging for developing more effective and lasting treatments for BV? Will effective antibiotics for South African women with BV need to be adjusted over time as the bacteria evolve?
I’m really interested to see more data on multi-strain, vaginally derived vaginal probiotics and how these perform as an adjunct to standard antibiotic therapy. Drug repurposing is also a really interesting line of research, and I’m excited to see how this research can be applied to vaginal microbiome modulation.
What are your long-term goals in this field, and how do you hope your research will impact the understanding and treatment of BV?
My long-term goal is to build up a really well characterised biorepository of Gardnerella species which can be available for use in large-scale collaborative projects for many years to come.
What advice would you give to young scientists, especially women, who are interested in pursuing research in microbiology or related fields?
Always be open to learning new skill sets. Always be on the lookout for how techniques being used in other areas of research may be relevant to what you are investigating. Most importantly, don’t be afraid to put your hand up and ask a question.
Hannah Livingstone’s work with VMRC4Africa highlights the importance of understanding the vaginal microbiome and its role in bacterial vaginosis. Her research provides valuable insights into developing more effective treatments, emphasising the need for geographically relevant studies. Through her dedication, Hannah aims to make a lasting impact on women’s health in Africa.
Watch Hannah’s FameLab video for more insights into her research
