Katharina Tenorio

Masterthesis

Title: Development and optimization of PCR-based detection of Y. pestis in medieval skeletal series from Creußen and Lübeck

The plague caused by Yersinia pestis (Y. pestis) hit Europe in pandemic waves throughout the last 2000 years. Particularly, the second pandemic also known as the Black Death (14th-18th century) claimed millions of lives and had significant impact on the socioeconomic development of Europe.
Y. pestis belongs to the genus Yersinia with 11 species, including two other human pathogens. The specific identification by PCR is difficult, because it has evolved as a clone of Y. pseudotuberculosis predominantly by gene loss and acquisition of virulence plasmids, e.g., the pla gene, which is frequently used as PCR target. Unfortunately, pla appears to be absent in Y. pestis from some phases of the second plague pandemic. Therefore, the use of multiple PCR targets should improve diagnostic efficacy. As phylogenetically close relatives of the pathogen may occur in soil, the sequencing of PCR products for the positive detections of the plague pathogen from historical archaeological skeleton material is essential.
The aims of my master's thesis are (1) to optimize and design PCR-based analysis systems for detection of Y. pestis and (2) to apply them to skeletal series from Creußen and Lübeck from the second plague pandemic. Knowledge gained from historical cases may provide better understanding of Y. pestis which has not yet been eradicated and is still a threatening pathogen, especially if it acquires antibiotic resistance.