Translational Microbiology
Discovering better ways to detect and prevent diseases caused by bacterial pathogens of major global health importance.
Our focus
Our group research focuses on bacterial pathogens of major global health importance, including:
- Streptococcus pneumoniae (the pneumococcus)
- Streptococcus pyogenes (group A streptococcus, GAS)
- Streptococcus agalactiae (group B streptococcus, GBS).
We investigate how infections are best diagnosed and prevented through vaccines, study how bacteria colonise, transmit and cause disease, and work closely with clinicians, epidemiologists and immunologists across the Asia‑Pacific region to support translation and global impact.
Our research areas
Improing vaccine strategies in low-middle income settings by identifying:
- Impact of vaccines in children and adults
- Optimal vaccination schedules
- Vaccine impact on antimicrobial resistance
- Improved vaccine strategies in humanitarian crisis settings
- Burden of pneumococcal disease in the Asia-Pacific.
Better diagnostics and disease surveillance using molecular microbiology
- Developing diagnostics for children with severe pneumonia
- Discovery of new serotypes and variants to inform vaccine and surveillance strategies
- Using genomics to understand antimicrobial resistance and the pneumococcal population structure.
Understanding the biology of bacterial pathogens and using laboratory and animal models to answer key questions for:
- Bacterial-viral interactions
- Bacterial colonisation and carriage
- Bacterial transmission and disease.
Contact us
For more information on our research at the Translational Microbiology group please contact us.
Ronan Chen, Research Assistant
Email:
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Group Leaders
Team Leaders
Group Members
Improved diagnostics for serious childhood pneumonia
MATE-Asia study
On target, on time: advancing diagnosis for children with complicated pneumonia across Asia.
Using molecular diagnostics to improve the detection of childhood lung infections, enabling better patient care and informing vaccine strategies across Asia.
Read more...Finding Pneumo
Community-acquired pneumonia (CAP) is a leading cause of childhood mortality and morbidity worldwide. Streptococcus pneumoniae (pneumococcus) is the leading bacterial cause with over 100 different serotypes.
Using cutting-edge techniques, including the technique developed in the MATE & MATE-Asia studies, we will determine the specific serotype of pneumococci causing disease in children with CAP and empyema (a severe form of pneumonia) across 6 hospitals in Australia.
We also aim to understand the effect of the most recently introduced pneumococcal conjugate vaccine which targets 20 serotypes (PCV20) on the pneumococcal serotype distribution in Australian children.
Vaccine strategies for low-middle-income countries
Vaccine impact studies
Introducing pneumococcal conjugate vaccines (PCV) results in a dramatic reduction in pneumococcal diseases such as pneumonia. PCVs also reduce colonisation (carriage) of the pneumococci included in the vaccine, preventing progression to disease and spread to others (herd protection).
Using microbiological techniques, we are measuring the impact of PCV on pneumococcal nasopharyngeal carriage in children and/or adults in Fiji, Mongolia, Lao and Papua New Guinea.
Vaccine trials
Despite the substantial reduction in pneumococcal disease following its introduction, there is little evidence to guide decision-makers on which vaccine to choose. The high price of the pneumococcal vaccines remains a significant barrier to implementation in many countries.
We used microbiology to assess differences in licensed vaccines and examine the effect of different schedules with fewer doses.
These trials were conducted in Ho Chi Minh City and Nha Trang to assess the impact on nasopharyngeal carriage, and therefore, likely herd protection.
Pneumococcal carriage following vaccine introduction
Use of genomics to determine the effect of vaccine introduction on pneumococcal antimicrobial resistance
Vaccine introduction reduces the carriage of vaccine serotypes (which tend to have more antimicrobial resistance (AMR)) and reduces the use of antibiotics by preventing pneumococcal infections.
Our aim is to determine the effectiveness of PCV13 against pneumococcal AMR in Lao and other settings.
Identify emerging non-vaccine serotypes and serotype persistence
There are over 100 serotypes of S. pneumoniae. The current pneumococcal vaccines protect against 10 or 13 serotypes. Following PCV introduction, non-vaccine types become more common (“serotype replacement”) in both carriage and disease. Vaccine types can also persist despite PCV introduction.
Using new molecular techniques, we determine which serotypes are causing severe pneumonia in children across Asia and monitor serotype replacement and serotype persistence.
We are using genomics to understand what subtypes (genetic lineages) may emerge in the post-PCV era to understand and address emerging future vaccination challenges, particularly around persisting serotypes and their public health importance.
Discovery of novel serotypes and variants
We are discovering and characterizing novel genetic variants (and potentially new serotypes) in low and middle-income countries across the Asia-Pacific
Our work aims to understand how these variants can be mistyped using common methods used in carriage studies and disease surveillance programs, and whether they would be targeted by existing vaccines, to inform future vaccine strategies.
Interactions of respiratory bacteria and viruses
Interactions between pneumococcus and viruses
The contribution of bacterial-viral co-infections to the onset and severity of disease is increasingly attracting global interest.
Co-infections of Streptococcus pneumoniae with respiratory viruses (e.g. Influenza or Respiratory Syncytial Virus) impact the severity of acute respiratory infections.
We aim to explain the interplay between pneumococci and respiratory viruses, understand the mechanisms involved and the implications and applications of these interactions for vaccines.
Group A streptococcus and viral interactions
The bacterium Streptococcus pyogenes (group A streptococcus, GAS or “Strep A”) causes a range of mild to severe infections, from sore throat to toxic shock syndrome. There is recent clinical epidemiological evidence that viruses are important in GAS pathogenesis, but little is known about this process.
We are using murine and specialized cell-culture models to examine the effect of viruses on S. pyogenes colonisation, transmission (spread), disease and the mechanisms involved.
Recently completed projects
Bulabula MaPei project
We investigated whether a single dose of oral azithromycin given to women in labour in Fiji reduces young infant Skin and Soft Tissue Infection (SSTI) rates and carriage of bacteria commonly causing maternal and infant infections.
More on Asia-Pacific Health projects
Centre of Research Excellence for Pneumococcal Disease - completed in 2025
This CRE was funded by the NHMRC until 2025 to gnerate new evidence to support decisions regarding the sustainability of national immunisation for pneumococcal conjugate vaccine (PCV) programs.
Funding
- Gates Foundation
- GAVI The Vaccine Alliance
- National Health and Medical Research Council
- Wellcome Trust
- Pfizer
- Research for Health in Humanitarian Crises
- The Murdoch Children’s Research Institute
- ISPPD - Robert Austrian Awards in Pneumococcal Vaccinology
- Jack Brockhoff Foundation
- MSD Pneumococcus Investigator Studies Program (MISP)
- Thrasher Research Fund
- Rebecca Cooper Fellowship
- Angior Foundation
- DHB foundation
- Victorian Critical Vaccinees Collection (VC2)
- National Variety Trials (NVT)
Collaborations
Australian collaborators
- Murdoch Children’s Research Institute (MCRI)
- Campus partners, including The Royal Children’s Hospital (RCH) - Centre for International Child Health (CICH) and The University of Melbourne Department of Paediatrics
- The University of Melbourne Department of Microbiology and Immunology
- Peter Doherty Institute
- La Trobe University
- Menzies School of Health Research
- Telethon Kids Institute
- QIMR Berghofer Medical Research Institute
- Sydney Children’s Hospitals Network (SCHN)
- The Children’s Hospital at Westmead
- Royal North Shore Hospital
- Queensland Children’s Hospital, Brisbane
- Perth Children’s Hospital
International collaborators
- Colonial War Memorial Hospital, Fiji
- The Fiji Ministry of Health and Medical Services
- The Mongolian Ministry of Health
- National Center of Communicable Diseases (NCCD), Mongolia
- Pasteur Institute, Vietnam
- St George’s University of London (SGUL), UK
- Laos-Oxford-Mahosot Welcome Research Unit (LOMWRU)
- Papua New Guinea Institute of Medical Research
- London School of Hygiene and Tropical Medicine
- Public Health England
- Eijkman Institute, Indonesia
- Universitas Padjadjaran/Hasan Sadikin General Hospital - Department of Child Health, Indonesia
- University of Bern, Switzerland
- Philippine General Hospital, University of the Philippines
- Duke-National University of Singapore, Singapore
- Siriraj Hospital, Mahidol University, Bangkok, Thailand
- Boston Children’s Hospital
- Yale School of Public Health
- Wellcome Sanger Institute, UK
Featured publications
Streptococcus pneumoniae nasopharyngeal carriage in Vietnamese children during the first five years of life: a post hoc analysis. Lancet Reg Health West Pac 2026. Marincek et al. DOI: 10.1016/j.lanwpc.2026.101805
Effect of pneumococcal conjugate vaccination on pneumococcal carriage in hospitalised children aged 2-59 months in Mongolia: an active pneumonia surveillance programme. The Lancet Microbe 2024. von Mollendorf et al. DOI: 10.1016/S2666-5247(24)00171-X
Effect of pneumococcal conjugate vaccine six years post-introduction on pneumococcal carriage in Ulaanbaatar, Mongolia. Nature Communications 2024. von Mollendorf et al. DOI: 10.1038/s41467-024-50944-3
Impact of reduced dose PCV10 schedules on pneumococcal carriage in Vietnam. New England Journal of Medicine 2024. Yoshida et al. DOI: 10.1056/NEJMoa2400007
Streptococcus pneumoniae serotype 33G: genetic, serological, and structural analysis of a new capsule type. Microbiology Spectrum 2024. Manna et al. DOI: 10.1128/spectrum.03579-23
Efficacy against pneumococcal carriage and the immunogenicity of reduced-dose (0 + 1 and 1 + 1) PCV10 and PCV13 schedules in Ho Chi Minh City, Viet Nam: a parallel, single-blind, randomised controlled trial. The Lancet Infectious Diseases 2023. Temple et al. DOI: 10.1016/S1473-3099(23)00061-0
Effect of different schedules of ten-valent pneumococcal conjugate vaccine on pneumococcal carriage in Vietnamese infants: results from a randomised controlled trial. The Lancet Regional Health Western Pacific 2022. Smith-Vaughan et al. DOI: 10.1016/j.lanwpc.2022.100651
Effect of ten-valent pneumococcal conjugate vaccine introduction on pneumococcal carriage in Fiji: results from four annual cross-sectional carriage surveys. The Lancet Global Health 2018. Dunne*, Satzke* et al. DOI: 10.1016/S2214-109X(18)30383-8
The PneuCarriage Project: A Multi-Centre Comparative Study to Identify the Best Serotyping Methods for Examining Pneumococcal Carriage in Vaccine Evaluation Studies. PLOS Medicine 2015. Satzke et al. DOI: 10.1371/journal.pmed.1001903
Standard method for detecting upper respiratory carriage of Streptococcus pneumoniae: updated recommendations from the World Health Organization Pneumococcal Carriage Working Group. Vaccine 2013. Satzke et al. DOI: 10.1016/j.vaccine.2013.08.062
Effect of ten-valent pneumococcal conjugate vaccine introduction on pneumococcal carriage in Fiji: results from four annual cross-sectional carriage surveys. Lancet Glob Health. 2018 Dec;6(12):e1375-e1385. Satzke et al. DOI: 10.1016/S2214-109X(18)30383-8
The PneuCarriage Project: a multi-centre comparative study to identify the best serotyping methods for examining pneumococcal carriage.
Plos Medicine 2015. Satzke et al. DOI: 10.1371/journal.pmed.1001903
Standard method for detecting upper respiratory carriage of Streptococcus pneumoniae: updated recommendations from the World Health Organization. Vaccine 2013. Satzke et al. DOI: 10.1016/j.vaccine.2013.08.062