Identification of Bartonella Trw host-specific receptor on erythrocytes.

Each Bartonella species appears to be highly adapted to one or a limited number of reservoir hosts, in which it establishes long-lasting intraerythrocytic bacteremia as the hallmark of infection. Recently, we identified Trw as the bacterial system involved in recognition of erythrocytes according to their animal origin. The T4SS Trw is characterized by a multiprotein complex that spans the inner and outer bacterial membranes, and possesses a hypothetical pilus structure. TrwJ, I, H and trwL are present in variable copy numbers in different species and the multiple copies of trwL and trwJ in the Bartonella trw locus are considered to encode variant forms of surface-exposed pilus components. We therefore aimed to identify which of the candidate Trw pilus components were located on the bacterial surface and involved in adhesion to erythrocytes, together with their erythrocytic receptor. Using different technologies (electron microscopy, phage display, invasion inhibition assay, far western blot), we found that only TrwJ1 and TrwJ2 were expressed and localized at the cell surface of B. birtlesii and had the ability to bind to mouse erythrocytes, and that their receptor was band3, one of the major outer-membrane glycoproteins of erythrocytes, (anion exchanger). According to these results, we propose that the interaction between TrwJ1, TrwJ2 and band 3 leads to the critical host-specific adherence of Bartonella to its host cells, erythrocytes.

Murine model for Bartonella birtlesii infection: New aspects.

As a model of persistent infection, various aspects of Bartonella birtlesii infection in laboratory mice, including some immunodeficient mice, are presented, particularly focusing on conditions mimicking natural infection. Bacteraemia was explored using different mice strains routes and inoculum doses (3.4-5x10(7)CFU/mouse). Mice became bacteraemic for 5 (C57Bl6/6) to 10 weeks (Balb/c, Swiss) with peaks ranging from 2x10(3) to 10(5)CFU/mL of blood. The ID route induced the most precocious bacteraemia (day 3) while the higher and longer bacteraemia in immunocompetent mice was obtained with SC when infecting Balb/c with approximately 10(3) CFU/mouse. As opposed to ID, SC and IV routes, bacteraemia was obtained with the oral and ocular routes only for high doses (10(7)) and in 33-66% mice. It was significantly higher and longer in CD4-/- mice compared to CD8-/- and double KO mice at most time points. CD8-/- mice and the control group had near to superimposed kinetics. These results confirm the relevance of the present model.

[Interaction of bacteria of the genus Bartonella with the host: inhibition of apoptosis, induction of proliferation, and formation of tumors].

The bacteria of the genus Bartonella are the causative agents for earlier not diagnosed or re-emergent diseases of the humans, danger of which increases in relation with increasing number of persons with the disturbed immune status. Bartonellae are intracellular parasites, the places of their habitation in the humans and animals are the endothelial cells of blood vessels and erythrocytes. The modern data concerning major factors of the Bartonellae virulence and host-bacteria interactions were considered and discussed in this article. The induction of the type IV secretion system, effector protein transmission, inhibition of the endothelial cells apoptosis, and induction of their proliferation lead to formation of new blood vessels and tumors.

Quantitative analysis of valvular lesions during Bartonella endocarditis.

Cardiac valve pathology was evaluated in 15 patients with confirmed diagnosis of Bartonella endocarditis. Ten were infected by Bartonella quintana and 5 by Bartonella henselae. Histologic features of these cases, including fibrosis, calcification, vegetation, pattern of inflammation, and vascularization, were compared with those of valves from 25 cases of non-Bartonella endocarditis as controls using a computerized quantitative image analysis. Pathologic and immunohistologic testing for localization of Bartonella species in resected valves included Warthin-Starry stain and polyclonal antibody-based immunodetection. Compared with other cases of infective endocarditis, cases of Bartonella endocarditis are more fibrotic and calcified, less vascularized, with less extensive vegetation and chronic inflammation. These pathologic changes are suggestive of a prolonged infection. Warthin-Starry stain and immunohistologic testing demonstrated the presence of the organism, respectively, in 11 and 10 of the 13 tested valves. Results of both staining methods showed microorganisms in extracellular locations and in regions unaccompanied by inflammation. Pathology and immunohistology may contribute to the etiologic diagnosis of Bartonella endocarditis when serology and molecular techniques are not available.

Involvement of host cell tyrosine phosphorylation in the invasion of HEp-2 cells by Bartonella bacilliformis.

We have provided evidence that exposure of human cells to protein kinase inhibitors results in decreased invasion of these cells by Bartonella bacilliformis in a dose-dependent manner. Preincubation of human laryngeal epithelial cells in the presence of genistein, a tyrosine protein kinase inhibitor, decreased the invasion of these cells by B. bacilliformis significantly. Further, exposure of normal human umbilical vein endothelial cells to staurosporine, a potent inhibitor of protein kinase C and some tyrosine protein kinases, resulted in a considerable reduction in the number of organisms internalized by these cells. Moreover, Bartonella infection of HEp-2 cells induced tyrosine phosphorylation of several Triton X-100 soluble proteins with approximate molecular masses of 243, 215 179, 172 (doublet), 160, 145 and 110 kDa that were absent or reduced in the presence of genistein in cells after 1 h of infection. Exposure of HEp-2 cell monolayers to anti-alpha 5 and anti-beta 1 chain integrin monoclonal antibodies resulted in a moderate decrease in the invasion of these cells, suggesting a possible role of alpha 5 beta 1 integrins in the uptake of Bartonella into nucleated cells.

Comparison of the abilities of proteins from Bartonella bacilliformis and Bartonella henselae to deform red cell membranes and to bind to red cell ghost proteins.

Infections in humans by Bartonella bacilliformis, but not Bartonella henselae, are characterized by invasion of red cells. Supernatants of culture medium from B. bacilliformis and B. henselae each contain a protein which causes invagination of membranes of human red cells and formation of intracellular vacuoles. These two proteins are very similar in molecular mass, heat stability and mechanism of action. B. henselae does not bind to human red cells, but human red cell ghost membrane proteins were recognized by both bacteria, five by B. bacilliformis and the same five, and one additional protein by B. henselae. Two of these proteins had molecular masses consistent with actin and spectrin. Actin binds to five electroblotted outer membrane proteins from B. henselae and four of these proteins are retained on an actin-Sepharose column.

Nuevas contribuciones al estudio de la Bartonelosis o Enfermedad de Carrión / New contributions to the study of disease or Bartonellosis Carrion

El estudio de 145 casos con Bartonelosis (68 en fase aguda y 77 en fase eruptiva) demostró que un 50 por ciento (34/68) de los pacientes en fase aguda eran residentes nativos de zonas endémicas, lo que revela la susceptibilidad de algunos nativos. Lugares principales de adquisición de la Bartonelosis fueron: 60.6 por ciento Ancash, 30.3 por ciento Lima, 3.4 por ciento Amazonas, 2.7 por ciento Cajamarca y 2 por ciento Huancavelica (probable nueva zona de Bartonelosis). Los síntomas en la fase aguda en orden de importancia son: fiebre, palidez, hiporexia, decaimiento general, debilidad, postración, cefalea; y en los pacientes en fase eruptiva: sangrado de las verrugas, fiebre, malestar general, artralgias. Signos importantes en los pacientes en fase aguda, son: 97 por ciento de palidez, 91.2 por ciento de regular a mal estado general, 82 por ciento hepatomegalia, 79.1 por ciento de fiebre, 75.2 por ciento de regular a mal estado nutricional, 77.9 por ciento soplo sistólico, 71.6 por ciento ictericia, 70.1 por ciento linfoadenomegalia. Otros signos destacados en la evolución fueron: 29.4 por ciento edema pretibial, 26.4 por ciento somnolencia, 22 por ciento mialgias, 16.4 por ciento derrame pericárdico, 14.7 por ciento fondo de ojo anormal (la gran mayoría con retinopatía hemorrágica), 10.2 por ciento convulsiones. Un hallazgo interesante fue la positividad en el frontis sanguíneo y el aislamiento de Bartonella bacilliformis en la sangre de 13 por ciento (2/15) de pacientes en fase eruptiva. En los pacientes agudos, el promedio del hematocrito inicial fue de 17.21 por ciento un 61 por ciento presentó leucocitosis inicial y sólo el 17.2 por ciento tuvo linfopenia, y ningún caso de leucopenia. El 60 por ciento tuvo incremento de bilirrubina total, predominando el incremento de la bilirrubina total, predominando el incremento de la bilirubina directa sobre la indirecta...

Infección "in vitro" de los hematies humanos por bartonella / Human hemocytes infection \"in vitro\" by bartonella

La Enfermedad de Carrión es producida por Bartonella bacilliformis a través de la picadura de insecto del género Lutzomyia. La bacteria después de un periodo de incubación en el RES, parasita a los hematies. Conociendo estos aspectos dinámicos de la Bartonella, nos llevó a realizar la réplica de la infección In-Vitro. Para lo cual utilizamos dos cepas de Bartonella (21 y 051), el medio Agar de Fases y hematíes de los diferentes grupos sanguíneos humanossanos. Cultivamos el complejo Hematíes-Bartonellas, utilizando 15 frascos de Kolle con Medio Agar de Fases para cada una de las cepas de Bartonella. Resultados: A partir del sexto día de incubación, se observó el parasitismo de los hematíes por la bacteria, siendo más acentuado a las dos semanas de incubación. Conclusión: el parasitismo hemático en la infección in-vitro, es parecido a la infección natural de las personas en zonas endémicas de Bartonelosis

Infección "in vitro" de los hematies humanos por bartonella / Infection in vitro from human red blood cells by Bartonella

La Enfermedad de Carrión es producida por Bartonella bacilliformis a través de la picadura de insecto del género Lutzomyia. La bacteria después de un periodo de incubación en el RES, parasita a los hematies. Conociendo estos aspectos dinámicos de la Bartonella, nos llevó a realizar la réplica de la infección In-Vitro. Para lo cual utilizamos dos cepas de Bartonella (21 y 051), el medio Agar de Fases y hematíes de los diferentes grupos sanguíneos humanossanos. Cultivamos el complejo Hematíes-Bartonellas, utilizando 15 frascos de Kolle con Medio Agar de Fases para cada una de las cepas de Bartonella. Resultados: A partir del sexto día de incubación, se observó el parasitismo de los hematíes por la bacteria, siendo más acentuado a las dos semanas de incubación. Conclusión: el parasitismo hemático en la infección in-vitro, es parecido a la infección natural de las personas en zonas endémicas de Bartonelosis.