Young Investigator Awardees 2006

Gilbert Daniel Greub born 1967 in Neuchatel, Switzerland; MD, PhD, researcher at the Institute of Microbiology, University of Lausanne, Switzerland, in recognition of his outstanding research accomplishments in the field of Chlamydia-like organisms. He described for the first time the developmental cycle of Parachlamydia, studied the genetic, evolutionary history, and interactions of this obligate intracellular organism with amoebae and macrophages, and demonstrated a role of Parachlamydia in pneumonia.

Research interests
Discovering new agents of pneumonia is the main objective of Gilbert Greub’s research group. To reach this goal, he uses amoebal co-culture to selectively grow amoebae-resisting bacteria, which allows investigation of their pathogenicity. Gilbert Greub provided serological and molecular evidence suggesting a role of Parachlamydia in pneumonia. He showed that this Chlamydia-like organism resists against human macrophages. Furthermore, he demonstrated that Parachlamydia remains unrecognised by macrophages and is able to modulate the biogenesis of phagosomes. He also showed the existence of the crescent body, an infectious developmental stage only present in Parachlamydiaceae. Recently, he discovered a F-like tra operon in a genomic island on the chromosome of a Parachlamydia-related bacteria. This is the first evidence of a putative conjugative DNA transfer among obligate intracellular bacteria. Further ongoing research is directed at elucidating the biology and pathogenicity of other amoebae-resisting chlamydiae such as Waddlia and Simkania.

Stephan Jürgen Harbarth born 1967 in Immenstadt, Germany; MD, MS, Senior Research Associate, hospital epidemiologist and attending physician at the University Hospital, Geneva, Switzerland, in recognition of his outstanding contributions in the field of infectious disease epidemiology, focussing on prevention and control of nosocomial infections and antimicrobial resistance in hospitals. In addition he pioneered studies on the cultural and regulatory factors that influence antimicrobial use in different countries.

Research Interests
Stephan Harbarth’s research interest is focussed on the epidemiology and prevention of antibiotic-resistant, healthcare-associated infections.  In particular, his studies on the impact and control of nosocomial MRSA transmission have increased our understanding of the epidemiology of MRSA and improved our ability to combat this microorganism.

His other important contributions to the field of antibiotic resistance, which had an impact on policy making, are research on the adverse effects of prolonged antibiotic prophylaxis after surgery and on the ecologic bias associated with group-level data analyses of antibiotic-use-versus-resistance relationships as well as several well conducted intervention studies.  For instance, in a recently published article, Stephan Harbarth investigated the clinical usefulness of a rapid on-admission screening test for MRSA. A substantial decrease in MRSA infections was seen in a medical ICU after increasing compliance with on-admission screening and implementing a strategy that linked the rapid test to pre-emptive isolation of MRSA patients.

Complementary research interests include the molecular epidemiology of emerging pathogens such as community-acquired MRSA, the pharmaco-epidemiology of antibiotic use (including international analyses of macro-level determinants of antibiotic overuse), and improved and rapid diagnosis of severe infections in critically ill patients.