Javier Pizarro-Cerda's upbringing gave him curiosity, an interest in biology and science, as well as a lifelong passion for music! After his studies in Costa Rica, he came to Europe to become a scientist.
Today at the Institut Pasteur in Paris, his research on plague and other Yersinia infections follows on from the work of his predecessors and also explores the history of deadly epidemics of the past.
After benefiting from such a rich inheritance, Javier is now keen to pass his knowledge on to future generations of scientists.
A tribute to his country, Costa Rica
Javier was born in the Costa Rican capital, San José. He remembers growing up surrounded by abundant nature, and he took pleasure in observing the natural environment. Every day in the garden of his family home, he would see birds in a kaleidoscope of colors – hummingbirds, brightly hued finches, motmots and many more. Costa Rica alone has over 800 bird species, more than the combined number of species in North America and Europe!
This fantastic biodiversity sparked his interest in studying biology and life sciences.
"As a family we would go for trips on Sundays to volcanoes at an altitude of 3,300m, and on the way we would see all sorts of wildlife – coatis, agoutis, armadillos, sloths and monkeys. The plant life was also lush and green, with tree ferns, flame trees, mango trees and orchids. From where we lived, we had the choice between traveling west to the Pacific coast or east to the Caribbean Sea."
A heritage of science and music
Javier's father was a pediatric physician in San José. He was also a scientist, researching potential therapeutic rehydration solutions for children affected by severe intestinal infections. Javier remembers that his father used to receive scientific journal articles through the post.
"I was intrigued by these letters with stamps from Italy, Hungary or elsewhere. They were a window onto the world!"
His father ultimately succeeded in developing a solution, known as "Pizarro's solution," which is still used in Latin America today.
Javier's mother worked in a bank. In her free time, she would play the guitar and sing Latin American songs, and that was something Javier grew to love, too. Wherever he has traveled, he has always played music on all sorts of different instruments. Together with Latin American colleagues at the Institut Pasteur, he founded the "Music Lab," a shared space where Institut Pasteur staff can meet and play music together. And he didn't think twice about making his own musical instruments available to get the Music Lab off the ground. In moments of down time with colleagues on the Paris campus, he loves playing jazz standards on the guitar or accompanying furious Chuck Berry riffs on the double bass!
Crossing borders and embracing an international scientific community
From an initial interest in biology, Javier turned his attention to microbiology, and he went to study at the University of Costa Rica. The classes on evolution and genetics were his favorite parts of the course. He also took French lessons at the Alliance française.
France has long been an inspiring country for Latin America because of its values, its culture and its art.
After university, Javier attended a school of veterinary medicine, where he began his research on bacterial diseases with Dr. Edgardo Moreno. He found himself working in collaboration with laboratories and scientists at the Marseille-Luminy Immunology Center.
At the age of 26, Javier headed for Europe, joining the team in Marseille to embark on a PhD. His team worked with Philippe Sansonetti, an eminent Institut Pasteur scientist.
For his postdoctoral studies, he joined Pascale Cossart's team, before becoming a Research Associate.
"When I arrived at the Institut Pasteur, during meetings, the scientists would look at me strangely because I spoke French with a hybrid Costa Rican–Marseille accent!"
"My working relationship with Pascale was intense and transparent. We published some landmark results, especially on the secretion of a natural antibiotic by Listeria bacteria."
A new heritage at the Institut Pasteur...
In 2017, Javier became Head of the Yersinia Unit and the World Health Organization (WHO) Collaborating Center for Plague, where his teams work on bubonic and pneumonic plague.
A week after he took up the role, WHO issued an international alert for what would be the worst plague outbreak for more than a century, in Madagascar.
The team headed to Madagascar to boost diagnostic capabilities in the field, and they worked with colleagues from the Institut Pasteur de Madagascar to characterize the Yersinia pestis strains responsible for the outbreak.
Building on the work of their predecessors, Javier and his teams are currently developing a bubonic plague vaccine. The results are promising, with a 100% success rate in a mouse model, and a patent has been filed.
In 2022, the team also conducted some remarkable comparative genetics research on the Black Death that swept through Europe in the Middle Ages. The scientists wanted to find out whether the plague bacillus had led to the selection of protective genes against the pathogen in humans. They analyzed ancient DNA samples extracted from the remains of individuals who died before, during and after the devastating plague pandemic. The results of their research revealed genetic variability in individuals who survived, which still persists in our genes today. The research also shows how the Black Death may have shaped the evolution of immunity genes, setting the course for how we currently respond to autoimmune diseases.
Plague is a fascinating topic because it draws on a wide range of knowledge: microbiology and public health – which are areas of expertise for our unit –, as well as human population genetics, paleogenomics and history, and we are lucky to be able to interact with colleagues who are experts in these disciplines and who enable us to travel back in time through human history.
Javier's laboratory hosts the National Reference Center for Plague and other Yersinia Infections, which also covers the intestinal infections caused by other bacteria in the genus Yersinia.
Of the 26 species in the genus Yersinia, three are pathogenic for humans.
Yersinia pestis is the pathogen responsible for bubonic plague, or Black Death.
But there are also two species which cause intestinal yersiniosis: Yersinia pseudotuberculosis and Yersinia enterocolitica.
These bacteria are present worldwide and are responsible for enteritis, especially in temperate countries. They are the third leading cause of bacterial enteritis in France and Europe. They mainly spread through fecal-oral transmission, after eating contaminated food.
The scientists are seeking to answer these two questions:
- How do the bacteria that cause intestinal yersiniosis circulate in France?
- What are the sources of contamination for humans?
"Over and above my role as a scientist, I like being able to pass on knowledge to new generations of scientists. I have taught on practical and theoretical courses in France, Argentina, Costa Rica, Greece and China. In France, I have also been involved in "Pint of Science" events, which aim to take science out of the lab and encourage interactions with the public over the course of an evening."
Key dates in Javier Pizarro-Cerda's career
1990 and 1994: BSc and MSc from the University of Costa Rica
1995 and 1998: DEA postgraduate degree and PhD from Aix-Marseille University, in Jean-Pierre Gorvel's laboratory
1998: "Clodomiro Picado Twight" Costa Rican National Science and Technology Award
1999-2017: Postdoctoral fellowship then Research Associate in the Bacteria-Cell Interactions Unit led by Pascale Cossart at the Institut Pasteur in Paris
2012: Member of the Costa Rican Academy of Sciences
2015: Medal from the French Senate for work to promote dialog between France and Latin America
2016: Head of the "Systems Biology of Bacterial Infections" group, promoted to Director of Research
2017: Georges, Jacques and Elias Canetti Prize, Institut Pasteur
During the course of his career, Javier Pizarro-Cerda has developed his research as a visiting scientist at various international laboratories, including the Center for Microscopy & Microanalysis (University of Queensland, Australia), the Weizmann Institute of Science (Rehovot, Israel), the University of Texas Southwestern (Dallas, United States), the Max Planck Institute for Infection Biology (Berlin, Germany) and the Biozentrum (Basel, Switzerland).