| Full text | |
| Author(s): |
Fernandes, Luis G. V.
;
Filho, Antonio F. S.
;
Souza, Gisele O.
;
Vasconcellos, Silvio A.
;
Romero, Eliete C.
;
Nascimento, Ana L. T. O.
Total Authors: 6
|
| Document type: | Journal article |
| Source: | MICROBIOLOGY-SGM; v. 162, n. 8, p. 1407-1421, AUG 2016. |
| Web of Science Citations: | 2 |
| Abstract | |
Pathogenic bacteria of the genus Leptospira are the causative agent of leptospirosis, an emergent infectious disease that affects humans and animals worldwide. Severe forms of the disease in humans include jaundice, multiple organ failure and intense haemorrhage. Up to now, mechanisms associated with the haemorrhage foci are poorly understood. We report in this work that, despite the low levels of antithrombin III in convalescent human serum samples, virulent, culture-attenuated and saprophyte strains of Leptospira are unable to bind and/or degrade this thrombin inhibitor, suggesting an indirect mechanism of pathogenesis. Lower levels of prothrombin were found in serum samples at the onset and convalescent phase of the disease when compared to normal human sera. The concomitant decreased levels of antithrombin III and prothrombin suggest a process of stimulated coagulation, which is corroborated by the increase of prothrombin fragment F1+2 in the serum samples. Data obtained with hamsters experimentally infected with virulent Leptospira interrogans serovars Kennewicki and Canicola strongly point out that haemorrhage is correlated with decreased levels of thrombin inhibitors and prothrombin. Activated coagulation might lead to an overconsumption of coagulation factors ultimately leading to bleeding and organ failure. (AU) | |
| FAPESP's process: | 14/50981-0 - Search for surface proteins among the genome sequences of Leptospira interrogans: functional and immunological characterization to understanding mechanisms involved in the bacterial pathogenesis |
| Grantee: | Ana Lucia Tabet Oller do Nascimento |
| Support Opportunities: | Research Projects - Thematic Grants |
| FAPESP's process: | 12/23913-9 - Indentification and characterization of proteins of Leptospira interrogans involved in host-pathogen interactions |
| Grantee: | Ana Lucia Tabet Oller do Nascimento |
| Support Opportunities: | Regular Research Grants |
| FAPESP's process: | 12/24164-0 - Characterization of the interaction of Leptospira interrogans with prothrombin/thrombin system and possible implications in virulence |
| Grantee: | Luis Guilherme Virgílio Fernandes |
| Support Opportunities: | Scholarships in Brazil - Doctorate |