Genotype Profiles of Actinobacillus pleuropneumoniae Isolated from Pigs in Vojvodina, Serbia
Background: Actinobacillus pleuropneumoniae (A. pleuropneumoniae) is one of the most important bacterial respiratory pathogens. It is the only etiological agent of porcine pleuropneumonia (PPP) or it appears as a secondary bacterial infection in the swine respiratory disease complex (PRDC). In Serbia, apart from the identification of serotype 2, no tests have been performed to establish the presence of other A. pleuropneumoniae serotypes in the pig population. The aim of this study was to perform genotyping of A. pleuropneumoniae isolates originating from pig farms in Serbia by apx genes and using multiplex polymerase chain reaction (mPCR).
Materials, Methods & Results: Isolates of A. pleuropneumoniae examined in this study were obtained from lungs with macroscopically visible alterations characteristic of a A. pleuropneumoniae. A total of 46 isolates were examined. They were extracted from the lung tissue samples of pig carcasses from 9 farms across different parts of Serbia. Genotyping of isolates was performed in the previously described manner. Briefly, 5 pairs of oligonucleotide primers were used for amplification of 4 different apx genes which encode synthesis of exotoxins (ApxI , ApxII , ApxIII i ApxIV) characteristic for all A. pleuropneumoniae serotypes and biovars. Amplification of appropriate genome parts was performed with a reaction chain polymerase (PCR) in multiplex (m) format using appropriate diagnostic kits to extract DNA from bacteria and perform mPCR reaction. The results of genotyping of 46 isolates of A. pleuropneumoniae indicate the existence of a large number of different serotypes of A. pleuropneumoniae on the studied farms or that different serotypes of this microorganism circulate in the pig population in Serbia. In addition to the detection of dominant serotype 2, which was established on 7 farms, of which in 4 farms it was the only detected serotype, in the examined pig population the presence of serotypes 3, 5, 6, 7 and 9 was also found. Furthermore, the presence of 2 different serotypes of A. Pleuropneumoniae was also detected on 3 farms; on the first farm serotypes 2 and 3, on the second farm serotypes 2 and 6, and on the third farm serotypes 2 and 7.
Discussion: Although the research was done with a relatively small number of isolates of A. pleuropneumoniae, comparing the obtained results with the results on the presence and prevalence of appropriate serotypes from other countries, we concluded that there is significant diversity of this pathogen in the pig population in farms of Serbia. Detection of different serotypes of A. pleuropneumoniae in the pig population and the presence of several different serotypes on 1 farm was established for the very first time in Serbia. All isolates from our study can be characterized as highly virulent, considering that the clinical symptoms, pathological findings and the results of bacteriological examination indicated A. pleuropneumoniae to be the cause of animal death. Like in the neighbouring countries, the strongly pathogenic serotype 9 and the less pathogenic serotype 2 are the most frequently identified causative agents of porcine pleuropneumonia in the Autonomous
Province of Vojvodina, Republic of Serbia. The necessity to establish the presence of all A. pleuropneumoniae serotypes in the pig population, and in particular to determine the presence of different serotypes on individual farms, is crucial for several reasons: making a definitive diagnosis; development of prophylactic strategies for medicines; implementation of immunoprophylactic vaccination.
Keywords: swine, porcine pleuropneumonia, PPP, serovar 2, serotype, lung, PCR.
Angen O., Heegaard P.M., Lavritsen D.T. & Sørensen V. 2001. Isolation of Actinobacillus pleuropneumoniae serotype 2 by immunomagnetic separation. Veterinary Microbiology. 79: 19-29.
Bosse J.T., Li Y., Sarkozi, R., Gottschalk M., Angen Ø., Nedbalcova K. & Langford P.R. 2017. A unique capsule locus in the newly designated Actinobacillus pleuropneumoniae serovar 16 and development of a diagnostic PCR. Journal of Clinical Microbiology. 55: 902-907.
Dubreuil J.D., Jacques Mario., Khyali R.M. & Gottschalk M. 2000. Actinobacillus pleuropneumoniae surface polysaccharides: their role in diagnosis andimmunogenicity. Animal Health Research Reviews. 1(2): 73-93.
Gottschalk M. 2015. The challenge of detecting herds sub-clinically infected with Actinobacillus pleuropneumoniae. Veterinary Journal. 206: 30-38.
Ivetić V., Žutić M., Romanić S., Valter D. & Drezga J. 1996. Prilog poznavanju aktinobacilusne pleuropneumonije i serovarne distribucije kauzalnog agensa u velikim aglomeracijama svinja. Zbornik kratkih sadržaja. 9. Savetovanja Veterinara Srbije (Zlatibor, Serbia).pp.107-109.
Rayamajhi N., Sung J., Sang G.K., Deog Y.L., Jeong M. & Han S.Y. 2005. Development and use of a multiplex polymerase chain reaction assay based on Apx toxin genes for genotyping of Actinobacillus pleuropneumoniae isolates. Journal of Veterinary Diagnostic Investigation. 17: 359-362.
Sarkozi R., Makrai L. & Fodor L. 2015. Identification of a proposed new serovar of Actinobacillus pleuropneumoniae: Serovar 16. Acta Veterinaria Hungarica. 63: 444-450.
Savić B., Radanović O., Jovičić D., Nešić K., Ivanović S., Stevančević O., Cvetojević Đ. & Kasagić D. 2015. Survey of infectious agents associated with porcine respiratory disease complex (PRDC) in serbian swine herds using polymerase chain reaction (PCR) detection. Acta Veterinaria Belgrade. 65(1): 79-88.
Schaller A., Kuhnert P., de la Puente-Redondo V.A., Nicolet J. & Frey J. 2000. Apx toxins in Pasteurellaceae species from animals. Veterinary Microbiology. 74: 365-376.
Žutić M., Lepšanović Z., Krnjajić D. & Ašanin R. 1999. Actimicrobial susceptibility and plasmid profiles of Actinobacillus pleuropneumoniae strains isolated from swine. Book of Abstracts 13th International Congress of the Hungarian Society for Microbiology (Budapest, Hungary). p.114.
How to Cite
Copyright (c) 2022 Kosta Kojić, Ognjen Stevančević, Božidar Savić, Nenad Stojanac, Ivana Davidov, Jovan Spasojević, Marko Cincović
This work is licensed under a Creative Commons Attribution 4.0 International License.
This journal provides open access to all of its content on the principle that making research freely available to the public supports a greater global exchange of knowledge. Such access is associated with increased readership and increased citation of an author's work. For more information on this approach, see the Public Knowledge Project and Directory of Open Access Journals.
We define open access journals as journals that use a funding model that does not charge readers or their institutions for access. From the BOAI definition of "open access" we take the right of users to "read, download, copy, distribute, print, search, or link to the full texts of these articles" as mandatory for a journal to be included in the directory.
La Red y Portal Iberoamericano de Revistas Científicas de Veterinaria de Libre Acceso reúne a las principales publicaciones científicas editadas en España, Portugal, Latino América y otros países del ámbito latino