Didier Raoult

Didier Raoult (born 13 March 1952) is a French biology researcher. He holds MD and PhD degrees, and specializes in infectious diseases. He is "classified among the first ten French researchers by the journal Nature, for the number of his publications (a credit of more than one thousand) and for his citations number, as it was reported in 2008 by the daily economic newspaper resuming his work.".^[1] Moreover, according to the source ISI Web Of Knowledge, Didier Raoult is the researcher who publishes the most in France to date (June 2012).

In 1984, he created ex nihilo the Rickettsia Unit at AMU. He also teaches infectious diseases in the Faculty of Medicine of the AMU, and since 1982 has managed 74 M.D. theses and since 1989, 38 PhD theses.

Since 2008, professor Raoult has been the director the "URMITE" i.e. the Research Unit in Infectious and Tropical Emergent Diseases, collaborating with CNRS (National Center for the Scientific Research), IRD (Research for the Development Institute), INSERM (National Institute of Health and Medical Research)and the Aix Marseille University, in Marseille. His laboratory employs 140 people, including 45 very active researchers who publish between 150 and 200 papers per year,^[1] and had produced 29 patents and he was involved in the creation of 4 startup to date.

Furthermore, in 2014, according to ISI Web of Knowledge, Didier Raoult microbiologist is the 7th most cited worldwide. He is also part of the list of 400 most cited authors in the biomedical world.^[2]

Early 2015, we can attribute to him 2,032 indexed publications and a h-index of 100 (Web of Science source 04.05.2015) including 7 papers in Science, and 2 in Nature, the two most visible scientific journals as one of Shanghai's ranking criteria.

Research topics

Giant Viruses

Raoult's team carried out the discovery of very large sizes of viruses :

• In 1992, the team discovers the largest virus known to date: the Mimivirus^[3]
• Later, they discover the first virophage,^[4] a virus able to infect another virus to reproduce. The discovery appears promising: "by exploiting this mechanism, scientists may consider profitably using the strategy of viral infection to attack the most resistant viruses."^[1]

• In 2009, the team discovers another giant virus, named Marseillevirus^[5]

• Since 2008, 4 new virophages were discovered e.g. Zamilon specific of genotypes.^[6]
• By using for the first time Vermamoeba, a protist living in humans and their environment, the team isolated eight strains of a new giant virus we named Faustovirus.^[7]

New bacteria

Since the 1990s, Raoult and his team have identified and described approximately 96 new pathogenic bacteria^[1] and showed their implication in human pathologies. Two bacteria have been named for him: Raoultella planticola and Rickettsia raoultii.

Rickettsia, Bartonella, Q fever

Raoult developed the field of the intracellular bacteria culture, then initiated the field of the emergent rickettsioses and with his team could identify 10 new human pathogenic Rickettsia species. The laboratory quickly became a National Reference Center (partnership with InVS : National Health Institute) and a WHO collaborator center.

For Bartonella, the team was the first to identify their role in endocarditis.

For Q fever, a disease transmitted by the bacterial agent Coxiella burnetii, the whole of the diagnostic protocols as well on serologic as molecular biology aspects were set up at the laboratory.^[8]

Whipple’s disease

Tropheryma whipplei, the causal agent of Whipple's disease, was described in 1907 by George Hoyt Whipple, M.D., but was isolated for the first time in Raoult's laboratory.^[9] The discovery of this bacteria completely changed the profile of the disease and it is now shown that the bacteria is relatively common in the environment and the stools.^[10]

Paleomicrobiology

Mediterranean Harbour, Marseilles has been exposed to multiple epidemics. This led Raoult's laboratory to collaborate with anthropologists and odontologists teams, in order to identify the cause of the plague epidemics. They developed an original technique of DNA extraction from dental pulp and showed that Yersinia pestis orientalis was at the origin of various plague epidemics (Justinian plague and medieval plague). This also led them to elucidate the cause of death of many of Napoleon’s soldiers during the Russian retreat, following the discovery of a mass grave in Vilnius. The possibilities of new discovery in this field are varied and promising.^[11]

Microbiogenomic

In 1999, Raoult decided to start a new program of genomics and to apply this to clinical microbiology. The team started with Rickettsia conorii and since then, 24 bacterial genomes have been sequenced, as well as those of 7 giant viruses (14 of these 31 sequenced genomes having been published)^[12]

Microbial culturomics

Microbial culturomics is a new approach of biodiversity applied to human microbiota. In a study carried out by the laboratory and published in Clinical Microbiology and Infection in September 2012,^[13] this technique permit us to realise five world records: - The largest number of bacterial species isolated from a human stool (human excrement) - The largest virus isolated from a human to date - The largest bacterium isolated from a man to date - The largest number of new bacterial species found in one study (31 species). - A recent review identified that more than 30% of the cultured microbes from the gut were first found by the team^[14] - In another work published in the Nature Microbiology journal in 2016, nearly 1,000 samples from the human digestive tract (stool, stomach, small intestine and colon) were analyzed. Professor Raoult's team was able to cultivate 1,170 different bacteria present in the digestive tract, including 247 species of bacteria that are entirely new. They also found 269 bacteria that were known only in the environment so they were isolated for the first time in humans and 250 bacteria that had already been isolated in humans but never in the digestive tract. All of these new species of bacteria are available in collections of international strains (Collection of Strains of the Rickettsia Unit, and Deutsche Sammlung von Mikroorganismen und Zellkulturen).^[15]

Probiotics

The last field of research developed by Raoult represents for him a major question of public health. It relates to the effects of probiotics and antibiotics on the gut flora of human beings and their possible effects on weight gain and weight loss.^[16][17] This is of particular relevance in terms of investigating possible causes of obesity.^[18]

In the journal Nature Reviews Microbiology of September 2009, Raoult indicated: "humans, particularly children, have been taking these same probiotics for many years, especially in fermented dairy products" and they would have their share of responsibility in the human obesity epidemic …" ^[19]

In 2012, he and his co-workers reported on host-specific effects of Lactobacillus species on weight change.^[20] His view that lactobacillus may contribute to weight-gain in some humans^[21] is controversial.^[22] According to Raoult, recent research results "suggest that manipulating the composition of the gut microbiota may prevent weight gain or facilitate weight loss in humans".^[18]

HIV en route to endogenisation

A work led by Didier Raoult and published in 2014 made an analogy between the evolution of the koala retroviruses that currently experience on-going endogenization and apparent spontaneous cure of HIV infection in 2 patients never treated with antiretrovirals and with no HIV-related clinical symptoms and no HIV RNA or DNA detected in the blood by standard diagnosis tests. HIV sequences obtained from these two patients using modern sequencing technologies showed that HIV genes were inactivated by replacement of tryptophan codons by stop cdons, which is probably due to the action of a cellular enzyme, APOBEC. This work is a paradigm shift in HIV research that considered eradication of any HIV DNA from patients cells as a necessary step towards a possible cure. It provides opportunities for assessment of the chances for patients of a spontaneously favorable course of HIV infection, and for treatment through the use of APOBEC ^[23]

Didier Raoult's book list

1. Kazar J, Raoult D. Rickettsiae and Rickettsial diseases. Slovak Academy of Sciences ed. Publishing House of the Slovak Academy of Sciences, 1991.
2. Argenson JN, Aubaniac JM, Curvale G, Groulier P, Drancourt M, Raoult D. L'infection ostéoarticulaire sur prothèse - Prévention, Diagnostic, Traitement. 1992.
3. Raoult D. Antimicrobial Agents and Intracellular Parasites. Boca Raton: CRC Press Book, 1993
4. Mege JL, Revillard JP, Raoult D. Immunité et Infection - Concepts immunologiques et perspectives thérapeutiques. Arnette, 1997.
5. Raoult D. Maîtrise de la prescription des antibiotiques dans les hôpitaux. Elsevier ed. Paris: Elsevier, 1998.
6. Raoult D. Dictionnaire de maladies infectieuses. Paris: Elsevier, 1998.
7. Yu VL, Merigan TC, Barriere SL, et al. Antimicrobial Therapy and Vaccines. Williams & Wilkins, 1998.
8. Raoult D, Nigoghossian JP, Cartapanis A. L'Université de la Méditerranée face aux défis du troisième millénaire. 1999.
9. Raoult D, Tilton R. Dictionnary of Infectious Diseases. Elsevier ed. Paris: Elsevier, 1999.
10. Raoult D. Les nouvelles maladies infectieuses. Que sais-je? ed. Paris: Presse Universitaires de France, 1999.
11. Raoult D, Brouqui P. Rickettsiae and Rickettsial Diseases at the Turn of the Third Millenium. Paris: Elsevier, 1999.
12. Yu VL, Weber R, Raoult D. Antimicrobial Therapy and Vaccine. 2d ed. New York: Apple Trees Production, LLC, 2002.
13. Hechemy KE, Avsic-Zupanc T, Childs JE, Raoult DA. Rickettsiology - present and Future Directions. Annals of the New York Academy of Sciences ed. United States of America: K-M Research/PCP, 2003.
14. Hechemy KE, Oteo JA, Raoult DA, Silverman DJ, Blanco JR. Rickettsioses - From Genome to proteome, Pathobiology, and Rickettsiae as an International Threat. Annals of the New York Academy of Sciences ed. New York: GYAT/PCP, 2005.
15. Raoult D. Les nouveaux risques infectieux, grippe aviaire, SRAS et après ? Paris: Lignes de Repères, 2005.
16. Hechemy KE, Oteo JA, Raoult DA, Silverman DJ, Blanco JR. Century of Rickettsiology - Emerging, reemerging Rickettsioses, Molecular Diagnostics, and Emerging Veterinary Rickettsioses. Annals of the New York Academy of Sciences ed. Boston,USA: Blackwell Publishing, 2006.
17. Raoult D, Parola P. Rickettsial Diseases. New York: Informa Healthcare USA, Inc, 2007.
18. Raoult D, Edition d'un ouvrage de référence sur les rickettsioses, 2007.
19. Raoult D, Drancourt M, Paleomicrobiology – Past Human Infection, Springer, 2008.
20. Raoult D, Dépasser Darwin, Plon, 2010.
21. Raoult D. Grippe aviaire, SRAS : vivre avec les nouveaux risques infectieux, 2012
22. Raoult D. De l'ignorance et de l'aveuglement : pour une science postmoderne, 2012
23. Raoult D. Of Ignorance and Blindness, 2013

See also

• Hospital of Timone
• Mimivirus
• Virophage
• Whipple's disease

Bibliography

• "Rencontre avec un chercheur de microbes", in Le Point, 1 January 2009, n° 1894.
• "Dépasser Darwin" (Beyond Darwin) 2011

References

1. 1 2 3 4 "Didier Raoult, a voluntary researcher". Les Échos. 29 October 2008. p. 13. 
2. ↑ Boyac, Kevin W.; Klavans, Richard; Sorensen, Aaron A.; Ioannidis, John P.A. (2013). "A list of highly influential biomedical researchers, 1996-2011". [European Journal of Clinical Investigation]. 43. DOI: 10.1111/eci.12171. 
3. ↑ Raoult, D; Audic, S; Robert, C; Abergel, C; Renesto, P; Ogata, H; La Scola, B; Suzan, M; Claverie, JM (2004). "The 1.2-megabase genomic sequence of Mimivirus". Science. 306 (5700): 1344–50. doi:10.1126/science.1101485. PMID 15486256. 
4. ↑ La Scola, B; Desnues, C; Pagnier, I; Robert, C; Barrassi, L; Fournous, G; Merchat, M; Suzan-Monti, M; Forterre, P; Koonin, Eugene; Raoult, Didier (2008). "The virophage is a single parasite of the giant mimivirus". Nature. 455 (7209): 100–4. doi:10.1038/nature07218. PMID 18690211. 
5. ↑ Boyer, M; Yutin, N; Pagnier, I; Barrassi, L; Fournous, G; Espinosa, L; Robert, C; Azza, S; Sun, S; Rossmann, M. G.; Suzan-Monti, M.; La Scola, B.; Koonin, E. V.; Raoult, D. (2009). "Giant Marseillevirus highlights the role amoebae have as a melting pot in emergence of chimeric microorganisms". Proceedings of the National Academy of Sciences. US. 106 (51): 21848–53. doi:10.1073/pnas.0911354106. PMC 2799887. PMID 20007369. 
6. ↑ Gaia M, Benamar S, Boughalmi M, Pagnier I, Croce O, Colson P, Raoult D, La Scola B. Zamilon, a novel virophage with Mimiviridae host specificity. PLoS One. 2014 ;9(4):e94923.
7. ↑ Reteno DG, Benamar S, Bou Khalil J, Andreani J, Armstrong N, Klose T, Rossmann M, Colson P, Raoult D, La Scola B. Faustovirus, an asfarvirus-related new lineage of giant viruses infecting amoebae. J Virol. 2015 Apr 15. [Epub ahead of print]
8. ↑ Raoult, Didier; Parola, Philippe (2007). Rickettsial Diseases. New York: Informed Healthcare. ISBN 978-0-8493-7611-5. 
9. ↑ Raoult, D; Birg, ML; Scola, B; Fournier, EP; Enea, M; Lepidi, H; Roux, V; Piette, JC; Vandenesch, F; Vital-Durand, Denis; Marrie, Tom J. (2000). "Cultivation of the bacillus of Whipple's disease". New England Journal of Medicine. 342 (9): 620–5. doi:10.1056/NEJM200003023420903. PMID 10699161. 
10. ↑ Fenollar, F; Puéchal, X; Raoult, D (2007). "Whipple's disease". New England Journal of Medicine. 356 (1): 55–66. doi:10.1056/NEJMra062477. PMID 17202456. 
11. ↑ Raoult, Didier; Drancourt, Michel (2008). Paleomicrobiology, past human infections. Heidelberg: Springer. ISBN 978-3-540-75854-9. 
12. ↑ Fournier, EP; Drancourt, M; Raoult, D (2007). "Bacterial genomic sequencing and its use in infectious diseases". Lancet Infect Say. 7 (11): 711–23. doi:10.1016/S1473-3099(07)70260-8. 
13. ↑ Lagier JC, Armougom F, Million M, Hugon P Pagnier I, Robert C, et al. Microbial culturomics: paradigm shift in the human gut microbiome study. Clinical Microbiology and Infection 2012; ePublication
14. ↑ Rajilic-Stojanovic M, et al.The first 1000 cultured species of the human gastrointestinal microbiota. FEMS Microbiol Rev 38 (2014) 996-1047
15. ↑ Lagier JC, Khelaifia S, Alou MT, Ndongo S, Dione N, Hugon P, Caputo A, Cadoret F, Traore SI, Seck EH, Dubourg G, Durand G, Mourembou G, Guilhot E, Togo A, Bellali S, Bachar D, Cassir N, Bittar F, Delerce J, Mailhe M, Ricaboni D, Bilen M, Dangui Nieko NP, Dia Badiane NM, Valles C, Mouelhi D, Diop K, Million M, Musso D, Abrahão J, Azhar EI, Bibi F, Yasir M, Diallo A, Sokhna C, Djossou F, Vitton V, Robert C, Rolain JM, La Scola B, Fournier PE, Levasseur A, Raoult D. Culture of previously uncultured members of the human gut microbiota by culturomics. Nat Microbiol. 2016 Nov 7;1:16203. doi: 10.1038/nmicrobiol.2016.203.
16. ↑ Raoult, D (2008). "Human microbiome: take-home lesson one growth promoters?". Nature. 454 (7205): 690–1. doi:10.1038/454690c. PMID 18685678. 
17. ↑ Angelakis E, Merhej V, Raoult D (2013). "Related actions of probiotics and antibiotics on gut microbiota and weight modification". The Lancet. Infectious Diseases (Review). 13 (10): 889–99. doi:10.1016/S1473-3099(13)70179-8. PMID 24070562. 
18. 1 2 Angelakis E, Armougom F, Million M, Raoult D (2012). "The relationship between gut microbiota and weight gain in humans". Future Microbiology (Review.). 7 (1): 91–109. doi:10.2217/fmb.11.142. PMID 22191449. 
19. ↑ Raoult, D (September 2009). "Probiotics and obesity: a link?". Nature Reviews Microbiology. 7 (9): 616. doi:10.1038/nrmicro2209. PMID 21548178. 
20. ↑ Million M, Angelakis E, Paul M, Armougom F, Leibovici L, Raoult D (August 2012). "Comparative meta-analysis of the effect of Lactobacillus species on weight gain in humans and animals". Microbial Pathogenesis. 53 (2): 100–8. doi:10.1016/j.micpath.2012.05.007. PMID 22634320. 
21. ↑ Million M, Raoult D (February 2013). "Species and strain specificity of Lactobacillus probiotics effect on weight regulation". Microbial Pathogenesis. 55: 52–4. doi:10.1016/j.micpath.2012.09.013. PMID 23332210. 
22. ↑ Lahtinen SJ, Davis E, Ouwehand AC (September 2012). "Lactobacillus species causing obesity in humans: where is the evidence?". Beneficial Microbes. 3 (3): 171–4. doi:10.3920/BM2012.0041. PMID 22968407. 
23. ↑ Colson, P; Ravaux, I; Tamalet, C; Glazunova, O; Baptiste, E; Chabrière, E; Wiedemann, A; Lacabaratz, C; Chefrour, M; Picard, C; Stein, A; Levy, Y; Raoult, D (2014-11-04). "HIV infection en route to endogenization: two cases". [Clin Microbiol Infect]. doi: 10.1111/1469-0691.12807.