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Freie Universität Berlin

1. Ewers, Christa. Molecular epidemiologic analyses of bacteria of the genera Pasteurella and Mannheimia to establish valid diagnostic tools based on Multiplex polymerase chain reactions.

Degree: 2006, Freie Universität Berlin

In this experimental thesis, an extensive collection of the important veterinary pathogenic genera Pasteurella and Mannheimia from various hosts and disease complexes were charac-terized with pheno- and genotypical methods. The molecular analyses were necessary to re-place the currently established ambiguous phenotypical identification methods with valid, unambiguous molecular tools. With these tools, future molecular epidemiological studies are enabled, which finally will lead to a valid analysis of the actual prevalence as well as the pathogenic role of these important veterinary pathogens. To our knowledge, with a total of 289 P. multocida ssp.-, 25 P. sensu stricto- as well as 104 M. species, for the first time such a large collection has been analysed, facilitating the establishment of valid diagnostical tools. Via PCR and DNA-DNA-hybridization, Pasteurella ssp. and spp. were investigated for the presence of 16 virulence associated genes [psl, ompH, oma87, ptf, pfha, nanB, nanH, toxA, tbpA, tonB, hgbA, hgbB, sodA, sodC, iga, escv], one spe-cies-specific [kmt] and five capsule genes [capA, capB, capD, capE, capF], while M. haemolytica and additional Mannheimia species were screened for the presence of 12 viru-lence associated genes [lktA, pomA, gcp, trBA, tonB, irp, sodA, sodC, escv, iga, adh]. Nearly all P. multocida ssp. strains showed a combination of genes, coding for outer membrane proteins (psl, ompH, oma87), colonisation factors (ptf, nanB, nanH), superoxide dismutase (sodC, sodA) as well as iron acquisition systems (tonB, hgbA, hgbB). In contrast, tbpA (31.5 %), coding for an iron acquisition system which seems to be specific for strains from ruminants, pfha (37.0 %), coding for filamentous hemagglutinine, as well as toxA (12.5 %), coding for dermonecrotoxin, were found to be less prevalent. Isolates of P. sensu stricto possessed mostly none of these genes, or, depending on the species investigated, ompH, oma87, psl and tonB only. Thus, genotypically these species could be easily differenti-ated from P. multocida ssp.. 86.9 % of the P. multocida ssp. harboured a combination of three genes encoding adhesins, namely ptf, nanH and nanB. In addition, 39.0 % of those strains reacted positive for pfhA, a gene which was rarely seen in strains of capsule type D (4.8 %). The simultaneous expression of fimbriae, sialidases and hemagglutinine in P. multocida ssp. is a fundamental requirement for successful infection of the host and host tissues, respec-tively, and may be one reason for the wide host spectrum of Pasteurella. Additionally, the finding that genes hgbA, hgbB and tonB, involved in iron acquisition, were found in combina-tion in 76.5 % of the strains, as well as the presence of tbpA in 20.4 % of them should theo-retically give P. multocida ssp. an advantage in multiplication in different hosts. Thus, the data generated also give relevant information for future experimental studies, investigating the role of adhesins as well as iron acquisition systems during pathogenesis of different… Advisors/Committee Members: n (gender), Univ.-Prof. Dr. L.H. Wieler (firstReferee), Univ.-Prof. Dr. W. Müller (furtherReferee), Univ.-Prof. em. Dr. E. Hellmann (furtherReferee).

Subjects/Keywords: Pasteurella; Mannheimia; Virulenzgenmuster; molekularbiologische Diagnostik; Multiplex-PCR; 600 Technik, Medizin, angewandte Wissenschaften::630 Landwirtschaft::630 Landwirtschaft und verwandte Bereiche

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APA · Chicago · MLA · Vancouver · CSE | Export to Zotero / EndNote / Reference Manager

APA (6th Edition):

Ewers, C. (2006). Molecular epidemiologic analyses of bacteria of the genera Pasteurella and Mannheimia to establish valid diagnostic tools based on Multiplex polymerase chain reactions. (Thesis). Freie Universität Berlin. Retrieved from http://dx.doi.org/10.17169/refubium-5296

Note: this citation may be lacking information needed for this citation format:
Not specified: Masters Thesis or Doctoral Dissertation

Chicago Manual of Style (16th Edition):

Ewers, Christa. “Molecular epidemiologic analyses of bacteria of the genera Pasteurella and Mannheimia to establish valid diagnostic tools based on Multiplex polymerase chain reactions.” 2006. Thesis, Freie Universität Berlin. Accessed September 18, 2020. http://dx.doi.org/10.17169/refubium-5296.

Note: this citation may be lacking information needed for this citation format:
Not specified: Masters Thesis or Doctoral Dissertation

MLA Handbook (7th Edition):

Ewers, Christa. “Molecular epidemiologic analyses of bacteria of the genera Pasteurella and Mannheimia to establish valid diagnostic tools based on Multiplex polymerase chain reactions.” 2006. Web. 18 Sep 2020.

Vancouver:

Ewers C. Molecular epidemiologic analyses of bacteria of the genera Pasteurella and Mannheimia to establish valid diagnostic tools based on Multiplex polymerase chain reactions. [Internet] [Thesis]. Freie Universität Berlin; 2006. [cited 2020 Sep 18]. Available from: http://dx.doi.org/10.17169/refubium-5296.

Note: this citation may be lacking information needed for this citation format:
Not specified: Masters Thesis or Doctoral Dissertation

Council of Science Editors:

Ewers C. Molecular epidemiologic analyses of bacteria of the genera Pasteurella and Mannheimia to establish valid diagnostic tools based on Multiplex polymerase chain reactions. [Thesis]. Freie Universität Berlin; 2006. Available from: http://dx.doi.org/10.17169/refubium-5296

Note: this citation may be lacking information needed for this citation format:
Not specified: Masters Thesis or Doctoral Dissertation

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