Identification of a class B acid phosphatase in Haemophilus parasuis Authors Paula Manrique-Ramírez Centre de Recerca en Sanitat Animal (CReSA), UAB-IRTA Núria Galofré-Milà Centre de Recerca en Sanitat Animal (CReSA), UAB-IRTA Marta Serrano Centre de Recerca en Sanitat Animal (CReSA), UAB-IRTA Virginia Aragon Centre de Recerca en Sanitat Animal (CReSA), UAB-IRTA Keywords: Haemophilus parasuis, non-specifi c acid phosphatases, phosphatase activity, Glässer’s disease Abstract An acid phosphatase activity was detected in the supernatant of Haemophilus parasuis, a Gram-negative pleomorphic bacillus and the causative agent of Glässer’s disease in pigs. To identify the gene responsible for the secreted activity, a genomic library of H. parasuis strain ER-6P was produced in Escherichia coli. Screening of the library allowed identifi cation of two homologs to known phosphatases: PgpB and AphA. PgpB was predicted to be located in the bacterial membrane through six transmembrane domains while AphA was predicted to have a signal peptide. The aphA gene was cloned and expressed in E. coli. Characterization of H. parasuis AphA indicated that this protein belongs to the class B nonspecifi c acid phosphatases. AphA contained sequence signatures characteristic of this family of phosphatases and its activity was inhibited by EDTA. The optimal pH of recombinant AphA differed from that of the phosphatase activity found in H. parasuis supernatants. In addition, the phosphatase activity from H. parasuis supernatants was not inhibited by EDTA, indicating that H. parasuis AphA does not account for the phosphatase activity observed in the supernatants. Our results demonstrate the presence of a class B acid phosphatase (AphA) in H. parasuis and suggest that the bacterium would also secrete another, as yet unidentifi ed phosphatase. [Int Microbiol 2014; 17(3):141-147]Keywords: Haemophilus parasuis · non-specifi c acid phosphatases · phosphatase activity · Glässer’s disease Author Biography Paula Manrique-Ramírez, Centre de Recerca en Sanitat Animal (CReSA), UAB-IRTA Downloads PDF Issue Vol. 17 No. 3 (2014) Section Research Articles License Submission of a manuscript to International Microbiology implies: that the work described has not been published before, including publication in the World Wide Web (except in the form of an Abstract or as part of a published lecture, review, or thesis); that it is not under consideration for publication elsewhere; that all the coauthors have agreed to its publication. The corresponding author signs for and accepts responsability for releasing this material and will act on behalf of any and all coauthors regarding the editorial review and publication process.If an article is accepted for publication in International Microbiology, the authors (or other copyright holder) must transfer to the journal the right–not exclusive–to reproduce and distribute the article including reprints, translations, photographic reproductions, microform, electronic form (offline, online) or any other reproductions of similar nature. Nevertheless, all article in International Microbiology will be available on the Internet to any reader at no cost. The journal allows users to freely download, copy, print, distribute, search, and link to the full text of any article, provided the authorship and source of the published article is cited. The copyright owner's consent does not include copying for new works, or resale. In these cases, the specific written permission of International Microbiology must first be obtained.Authors are requested to create a link to the published article on the journal's website. The link must be accompanied by the following text: "The original publication is available on LINK at <http://www.im.microbios.org>. Please use the appropiate URL for the article in LINK. Articles disseminated via LINK are indexed, abstracted, and referenced by many abstracting and information services, bibliographic networks, subscription agencies, library networks, and consortia.
