Mechanisms of Pathogenesis, Infective Dose and Virulence in Human Parasites

PLoS Pathogens

Helen C. Leggett¹  Charlie K. Cornwallis¹  Stuart A. West¹ 

[1] Department of Zoology, Oxford University, Oxford, United Kingdom

关键词: Parasitic diseases;    Pathogens;    Bacterial pathogens;    Virulence factors;    Dose prediction methods;    Skin infections;    Parasite evolution;    Staphylococcal infection;   

DOI  :  10.1371/journal.ppat.1002512

学科分类：生物科学（综合）

来源: Public Library of Science

【 摘 要 】

The number of pathogens that are required to infect a host, termed infective dose, varies dramatically across pathogen species. It has recently been predicted that infective dose will depend upon the mode of action of the molecules that pathogens use to facilitate their infection. Specifically, pathogens which use locally acting molecules will require a lower infective dose than pathogens that use distantly acting molecules. Furthermore, it has also been predicted that pathogens with distantly acting immune modulators may be more virulent because they have a large number of cells in the inoculums, which will cause more harm to host cells. We formally test these predictions for the first time using data on 43 different human pathogens from a range of taxonomic groups with diverse life-histories. We found that pathogens using local action do have lower infective doses, but are not less virulent than those using distant action. Instead, we found that virulence was negatively correlated with infective dose, and higher in pathogens infecting wounded skin, compared with those ingested or inhaled. More generally, our results show that broad-scale comparative analyses can explain variation in parasite traits such as infective dose and virulence, whilst highlighting the importance of mechanistic details.

【 授权许可】

CC BY