The OmpA-like protein Loa22 is essential for leptospiral virulence.
Pathogenic mechanisms of Leptospira interrogans, the causal agent of leptospirosis, remain largely unknown. This is mainly due to the lack of tools for genetic manipulations of pathogenic species. In this study, we characterized a mutant obtained by insertion of the transposon Himar1 into a gene encoding a putative lipoprotein, Loa22, which has a predicted OmpA domain based on sequence identity. The resulting mutant did not express Loa22 and was attenuated in virulence in the guinea pig and hamster models of leptospirosis, whereas the genetically complemented strain was restored in Loa22 expression and virulence. Our results show that Loa22 was expressed during host infection and exposed on the cell surface. Loa22 is therefore necessary for virulence of L. interrogans in the animal model and represents, to our knowledge, the first genetically defined virulence factor in Leptospira species.
Ristow
Paula
P
Unité de Biologie des Spirochètes, Institut Pasteur, Paris, France.
Bourhy
Pascale
P
da Cruz McBride
Flávia Weykamp
FW
Figueira
Claudio Pereira
CP
Huerre
Michel
M
Ave
Patrick
P
Girons
Isabelle Saint
IS
Ko
Albert I
AI
Picardeau
Mathieu
M
D000818:Animals; D001425:Bacterial Outer Membrane Proteins / Q000502:physiology*; D001483:Base Sequence; D006224:Cricetinae; D004251:DNA Transposable Elements; D004195:Disease Models, Animal; D006168:Guinea Pigs; D007668:Kidney / Q000378:metabolism / Q000382:microbiology / Q000473:pathology; D007921:Leptospira interrogans / Q000378:metabolism / Q000472:pathogenicity*; D007922:Leptospirosis / Q000382:microbiology*; D008099:Liver / Q000378:metabolism / Q000382:microbiology / Q000473:pathology; D008168:Lung / Q000378:metabolism / Q000382:microbiology / Q000473:pathology; D008969:Molecular Sequence Data; D017434:Protein Structure, Tertiary; D013154:Spleen / Q000378:metabolism / Q000382:microbiology / Q000473:pathology; D014774:Virulence
D001425:Bacterial Outer Membrane Proteins; D004251:DNA Transposable Elements; C078167:OMPA outer membrane proteins