Parasitology



Heterogeneity in extracellular nucleotide hydrolysis among clinical isolates of Trichomonas vaginalis


T. TASCA a1a2a3, C. D. BONAN a4, G. A. DE CARLI a3, J. J. F. SARKIS a2 and J. F. ALDERETE a1c1
a1 Department of Microbiology, MC7758, University of Texas Health Science Center, 7703 Floyd Curl Drive, San Antonio, TX 78229-3900, USA
a2 Departamento de Bioquímica, Instituto de Ciências Básicas da Saúde, Universidade Federal do Rio Grande do Sul, Rua Ramiro Barcelos 2600 – Anexo, 90035-003 Porto Alegre, RS, Brazil
a3 Laboratório de Parasitologia Clínica, Departamento de Análises Clinicas, Faculdade de Farmácia, Pontificia Universidade Católica do Rio Grande do Sul, Avenida Ipiranga, 6681, Caixa Postal 1429, 90619-900, Porto Alegre, RS, Brazil
a4 Laboratório de Pesquisa Bioquímica, Departamento de Ciências Fisiológicas, Faculdade de Biociências, Pontificia Universidade Católica do Rio Grande do Sul, Avenida Ipiranga, 6681, Caixa Postal 1429, 90619-900, Porto Alegre, RS, Brazil

Article author query
tasca t   [PubMed][Google Scholar] 
bonan cd   [PubMed][Google Scholar] 
de carli ga   [PubMed][Google Scholar] 
sarkis jj   [PubMed][Google Scholar] 
alderete jf   [PubMed][Google Scholar] 

Abstract

Trichomonas vaginalis is a parasitic protozoan that causes trichomonosis, a sexually-transmitted disease, with serious sequelae to women and men. As the host–parasite relationship is complex, it is important to investigate biochemical aspects of the parasite that contribute to our understanding of trichomonal biology and pathogenesis. Nucleoside triphosphate diphosphohydrolase 1 (NTPDase 1), which hydrolyses extracellular ATP and ADP, and ecto-5′-nucleotidase, which hyrolyses AMP, have been characterized in laboratory isolates of T. vaginalis. Here we show that the extracellular ATP[ratio]ADP hydrolysis ratio varies among fresh clinical isolates, which presented higher ATPase and ADPase activities than long-term-grown isolates. Growth of parasites in iron-replete and iron-depleted medium resulted in different, albeit minor, patterns in extracellular ATP and ADP hydrolysis among isolates. Importantly, some isolates had low or absent ecto-5′-nucleotidase activity, regardless of environmental conditions tested. For isolates with ecto-5′-nucleotidase activity, high- and low-iron trichomonads had increased and decreased levels of activity, respectively, compared to organisms grown in normal TYM-serum medium. This suggests a regulation in expression of either the enzyme amounts and/or activity under the control of iron. Finally, we found no correlation between the presence or absence of dsRNA virus infection among trichomonad isolates and NTPDase and ecto-5′-nucleotidase activities.

(Received August 5 2004)
(Revised January 11 2005)
(Accepted January 12 2005)


Key Words: Trichomonas vaginalis; nucleoside triphosphate diphosphohydrolase; ecto-5′-nucleotidase; fresh isolates; heterogeneity.

Correspondence:
c1 Department of Microbiology, MC7758, UTHSCSA, 7703 Floyd Curl Drive, San Antonio, TX 78229-3900, USA. Tel: +210 567 3940. Fax: +210 567 6612. E-mail: alderete@uthscsa.edu


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