The OmpA-Like Protein Loa22 Is Essential for Leptospiral Virulence

Children's Hospital Boston, United States of America
PLoS Pathogens (Impact Factor: 8.06). 08/2007; 3(7):e97. DOI: 10.1371/journal.ppat.0030097
Source: PubMed

ABSTRACT Author Summary

The spirochetes, which include medically important pathogens such as the causative agents of Lyme disease, syphilis, and leptospirosis, constitute an evolutionarily unique group of bacteria. Leptospirosis is a zoonotic disease that causes a high rate of mortality and morbidity in humans and animals throughout the world each year. The year 2007 marks the centenary of the discovery of the causative agent of leptospirosis, Leptospira interrogans. Until now, the genetic obstacles posed by leptospires (principally, the difficulties in generating targeted mutants) have hampered the identification of virulence genes. In this study, we describe an avirulent mutant in a pathogenic Leptospira that was obtained via disruption of loa22, a gene that encodes an outer membrane protein containing an OmpA domain. This mutation resulted in an avirulent mutant in the guinea pig model, and reintroduction of loa22 into the mutant restored Leptospira's ability to kill guinea pigs. Our results therefore indicate that loa22 is a virulence determinant that is, to our knowledge, the first identified for this pathogen.


Available from: Albert I Ko, Sep 24, 2014
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