Y Pestis Essay

Y. pestis is a nonmotile, gram-negative, nonsporulating, rod-shaped coccobacillus and a facultative anaerobe. Infamous for being the causative agent in plague, has been implicated in at least three devastating pandemics in modern history. The second plague pandemic includes the Black Death epidemic which caused the deaths of a third of the estimated European population in the fourteenth century (Haensch et al, 2010). More than five hundred years after the Black Death, during the third plague pandemic, Y. pestis was finally discovered and isolated by Alexandre Yersin, the organism’s namesake (Wayangankar et al, 2015). Before Yersin’s findings, little to nothing could be done to treat plague victims, but now that the cause of the disease is evident, treatment is both effective and relatively affordable (Perry and Fetherston, 1997). Although occurrences of plague are still reported around the world, they are often isolated outbreaks concentrated in overcrowded areas of third-world countries (Wayangankar et al, 2015). The discovery of plague’s etiological agent and the study of its pathogenesis has led to a significant reduction in its incidence rate around the world and near eradication in the developed world. Genomic comparison between modern and medieval strains of Y. pestis show no unique characteristics which suggests that perceived increase in virulence during the second pandemic is not due to a phenotypical change. Thus, other external factors like the environment, vector of infection, and susceptibility of hosts must account for the rapid and widespread …show more content…
pestis forms a gel-like envelope around the cell. Production of this protein is crucial to pathogenicity which explains the lack of virulence in fleas whose average body temperature is closer to 25°C. Presence of antibodies for the F1 antigen is correlated with infection resistance in animals and may be comparable in humans (Perry and Fetherston,