Acta Veterinaria Hungarica 55 (2), pp. 219–227 (2007) DOI: 10.1556/AVet.55.2007.2.8 0236-6290/$ 20.00 ' 2007 Akadémiai Kiadó, Budapest PREVALENCE OF SELECTED ENTEROPATHOGENIC BACTERIA IN HUNGARIAN FINISHING PIGS I. BIKSI 1* , MÆrta LŐRINCZ 1 , BeÆta MOLN`R 1 , T. KECSKS 2 , N. TAK`CS 3 , Darja MIRT 4 , A. CIZEK 5 , Z. PEJSAK 6 , G.-P. MARTINEAU 7 , J.-L. SEVIN 8 and O. SZENCI 1 1 Diagnostic Laboratory, Faculty of Veterinary Science, Szent IstvÆn University, H-2225 llő, Hungary; 2 Nagisz ZRt., NÆdudvar, Hungary; 3 Veterinary Diagnostic Services, New Mexico State University, Albuquerque, New Mexico, USA; 4 Novartis Veterina d.o.o., Ljubljana, Slovenia; 5 Institute of Microbiology and Immunology, University of Veterinary and Pharmaceutical Sciences, Brno, Czech Republic; 6 Swine Diseases Department, National Veterinary Research Institute, Puławy, Poland; 7 Ecole Nationale VØtØrinaire de Toulouse, France; 8 Coopagri Bretagne, France (Received 10 July 2006; accepted 20 September 2006) The aim of this study was to obtain prevalence estimates about the most important enteropathogenic bacteria: Lawsonia intracellularis, Brachyspira hyodysenteriae, Brachyspira pilosicoli, Salmonella enterica and Clostridium per- fringens A and C in Hungarian farrow-to-finish pig herds. A total of 31 herds were selected, from where six pooled faecal samples, each containing three indi- vidual rectal faecal samples were collected from fattening pigs of 56 months of age. All 186 samples were examined by polymerase chain reaction (PCR) for the presence of the pathogens mentioned above. Lawsonia intracellularis was found in 29 herds (93.55%) and in 108 samples (58.06%); B. hyodysenteriae in 14 herds (45.16%) and in 23 samples (12.37%); B. pilosicoli in 19 herds (61.29%) and in 53 samples (28.49%); S. enterica in 17 herds (54.83%) and in 40 samples (21.50%). We detected the presence of C. perfringens A in 19 herds (61.29%) and in 46 samples (24.73%), while C. perfringens C was found in 8 herds (25.81%) and in 11 samples (5.91%). All examined herds were infected with one or more of these agents. Herds with diarrhoea in the mid- to late finishing phase had almost 10 times higher prevalence of B. hyodysenteriae than herds without such a history. Key words: Lawsonia intracellularis, Brachyspira spp., Salmonella en- terica, Clostridium perfringens, prevalence, polymerase chain reaction (PCR) Enteric diseases in the fattening phase account for significant losses worldwide. The most important pathogens in this production stage are Lawsonia * Corresponding author: Imre Biksi; E-mail: biksi.imre@aotk.szie.hu; Fax: 0036 (29) 521-303