Michel Signoli

Yersinia pestis Orientalis in remains of ancient plague patients.

Yersinia pestis DNA was recently detected in human remains from 2 ancient plague pandemics in France and Germany. We have now sequenced Y. pestis glpD gene in such remains, showing a 93-bp deletion specific for biotype Orientalis. These data show that only Orientalis type caused the 3 plague pandemics.

New forensic approach to age determination in children based on tooth eruption

The present study proposes equations for age determination both in living and dead children, obtained with the help of stepwise ascending multiple linear regression. The equations should be applied, based on the number of erupted teeth and tooth germs, which were detected on radiographs, during clinical examination and in infant skeletal remains. The proposed equations proved to be efficient just like Demirjians method used as a reference today, and permit age estimation till 20 years of age.

Evidence of a Louse-Borne Outbreak Involving Typhus in Douai, 1710-1712 during the War of Spanish Succession

Background The new field of paleomicrobiology allows past outbreaks to be identified by testing dental pulp of human remains with PCR. Methods We identified a mass grave in Douai, France dating from the early XVIIIth century. This city was besieged during the European war of Spanish succession. We tested dental pulp from 1192 teeth (including 40 from Douai) by quantitative PCR (qPCR) for R. prowazekii and B. quintana. We also used ultra-sensitive suicide PCR to detect R. prowazekii and genotyped positive samples. Results and Discussion In the Douai remains, we identified one case of B. quintana infection (by qPCR) and R. prowazekii (by suicide PCR) in 6/21 individuals (29%). The R. prowazekii was genotype B, a genotype previously found in a Spanish isolate obtained in the first part of the XXth century. Conclusion Louse-borne outbreaks were raging during the XVIIIth century; our results support the hypothesis that typhus was imported into Europe by Spanish soldiers from America.

Limits of the Lamendin method in age determination

This study shows that epithelial attachment level, used as age determination criterion in Lamendins method, is not reliable for adults of either sex above the age of 49 years with periodontal diseases in any quadrant. The underestimation of calculated age increases from 7 to 19 years with chronological age. On the other hand, the present paper confirms the pertinence of dentin translucency as an age indicator in Lamendins method.

High Throughput, Multiplexed Pathogen Detection Authenticates Plague Waves in Medieval Venice, Italy

Background Historical records suggest that multiple burial sites from the 14th–16th centuries in Venice, Italy, were used during the Black Death and subsequent plague epidemics. Methodology/Principal Findings High throughput, multiplexed real-time PCR detected DNA of seven highly transmissible pathogens in 173 dental pulp specimens collected from 46 graves. Bartonella quintana DNA was identified in five (2.9%) samples, including three from the 16th century and two from the 15th century, and Yersinia pestis DNA was detected in three (1.7%) samples, including two from the 14th century and one from the 16th century. Partial glpD gene sequencing indicated that the detected Y. pestis was the Orientalis biotype. Conclusions These data document for the first time successive plague epidemics in the medieval European city where quarantine was first instituted in the 14th century.

Sexual dimorphism in teeth: discriminatory effectiveness of permanent lower canine size observed in a XVIIIth century osteological series

Recent studies have shown that the most dimorphic tooth is the mandibular canine. We have carried out a study on a random sample of 146 skeletons dating from the plague outbreak in Marseilles (1722). We studied 1284 maxillary and 1432 mandibular permanent teeth. Sexual dimorphism was tested on 89 individuals. We selected a set of four dental indices and calculated the dimorphism percentage by ratio expression male/female. Dimorphic ranking was made, by allotting the first rank to the tooth presenting the highest dimorphism and the last rank to the one presenting the lowest ratio. Comparisons of means were made on both sexes (sex determined by post-cranial data) through a Students test (t-test). We noted that lower canines and lateral incisor are the most interesting teeth in the dimorphic dental determination. The lower index presented the highest relative risk with RR = 1.56 [1.04-2.32]. In 58% of the cases, the lower dental index enabled a correct sex determination (determined on the basis of the post-cranial skeleton). These results showed the existence of a relative dental dimorphism (male > female mesiodistal diameters) with humans. In conclusion, this method, using dental measurements, may be used as an additional technique to determine sex on fragmentary adult skeletons, immature material, missing pieces or ambiguities on post-cranial remains.

Paleodemography and Historical Demography in the Context of an Epidemic: Plague in Provence in the Eighteenth Century

Abstract This article sheds an entirely new light on the study of the plague thanks to contributions from disciplines that are only seldom brought together around the same research topic: anthropology, archaeology, historical demography, history, microbiology and paleodemography. It confronts two types of documents: biological archives (the skeletons) and historical archives, the comparative study of which has provided new and original information.Distribution of the casualties by sex, age and intensity of the epidemic phase has been established and compared with previous results. The age distribution of deaths from the plague differs from “natural” mortality profiles and from deaths resulting from other epidemics or other demographic crises. The plague epidemic may be characterized as “non selective”, given that the bio- or paleodemographic sample may be considered as a reflection of the structure of the living population, something which is rarely observed.The results that we present concern a recent period for which the historical archives are of exceptional richness and provide a great deal of information on modern plague epidemics. The results from anthropological fieldwork and microbiology enable us to envisage similar research on more ancient epidemics, even in the absence of written documents.

Restricted diversity of dental calculus methanogens over five centuries, France.

Methanogens are acknowledged archaeal members of modern dental calculus microbiota and dental pathogen complexes. Their repertoire in ancient dental calculus is poorly known. We therefore investigated archaea in one hundred dental calculus specimens collected from individuals recovered from six archaeological sites in France dated from the 14th to 19th centuries AD. Dental calculus was demonstrated by macroscopic and cone-beam observations. In 56 calculus specimens free of PCR inhibition, PCR sequencing identified Candidatus Methanobrevibacter sp. N13 in 44.6%, Methanobrevibacter oralis in 19.6%, a new Methanomassiliicoccus luminyensis-like methanogen in 12.5%, a Candidatus Nitrososphaera evergladensis-like in one and Methanoculleus bourgensis in one specimen, respectively. One Candidatus Methanobrevibacter sp. N13 dental calculus was further documented by fluorescent in situ hybridization. The prevalence of dental calculus M. oralis was significantly lower in past populations than in modern populations (P = 0.03, Chi-square test). This investigation revealed a previously unknown repertoire of archaea found in the oral cavity of past French populations as reflected in preserved dental calculus.

Paléodémographie et démographie historique en contexte épidémique : la peste en Provence au XVIIIe siècle

Cet article apporte un eclairage totalement nouveau a l’etude de la peste grâce aux apports de disciplines qui ne se rencontrent que rarement autour d’un meme sujet de recherche : anthropologie, archeologie, demographie historique, histoire, microbiologie et paleodemographie. Il confronte deux types de documents : les archives biologiques (les squelettes) et les archives historiques, dont la mise en parallele a apporte des informations originales et inedites.La repartition des victimes par sexe, par âge et selon l’intensite de la phase epidemique a pu etre etablie et comparee a des resultats anterieurs. La repartition des deces par peste selon l’âge differe des profils de mortalite « naturelle » et de ceux resultant d’autres epidemies ou d’autres crises demographiques. On peut qualifier l’epidemie de peste de « non selective », l’echantillon bio- ou paleodemographique pouvant etre tenu comme un reflet de la structure de la population vivante, cas de figure qui est rarement observe.Les resultats que nous presentons concernent une periode recente pour laquelle les archives historiques sont d’une richesse exceptionnelle, ce qui nous offre une tres bonne connaissance des epidemies de peste modernes. Les resultats obtenus en anthropologie de terrain et en microbiologie nous permettent d’envisager des recherches similaires sur des epidemies plus anciennes, meme en l’absence de documents ecrits.

Paleoproteomics of the Dental Pulp: The plague paradigm

Chemical decomposition and fragmentation may limit the detection of ancient host and microbial DNA while some proteins can be detected for extended periods of time. We applied paleoproteomics on 300-year-old dental pulp specimens recovered from 16 individuals in two archeological funeral sites in France, comprising one documented plague site and one documented plague-negative site. The dental pulp paleoproteome of the 16 teeth comprised 439 peptides representative of 30 proteins of human origin and 211 peptides representative of 27 proteins of non-human origin. Human proteins consisted of conjunctive tissue and blood proteins including IgA immunoglobulins. Four peptides were indicative of three presumable Yersinia pestis proteins detected in 3/8 dental pulp specimens from the plague-positive site but not in the eight dental pulp specimens collected in the plague-negative site. Paleoproteomics applied to the dental pulp is a new and innovative approach to screen ancient individuals for the detection of blood-borne pathogens and host inflammatory response.