SEROLOGICAL PROFILES FOR LAWSONIA INTRACELLULARIS IN SWINE FARMS

Abstract

Farm prevalence studies in several countries in Europe, Asia and Northern America indicated that 24 to 47% of pig farms had a serious incidence with PPE in the past years. Herd prevalence for finishing pigs in other EU countries has been estimated to range between 88 and 100% (1, 2, 3). Porcine proliferative enteropathy (PPE) known as porcine proliferative ileitis is produced by Lawsonia intracellularis. PPE affects animals from 6 weeks of age and produce important damage, diarrhoea and poor performance in growing pigs. PPE are observed most commonly in the postweaned pig between 6 and 20 weeks of age. The purpose of this study was to determine the prevalence of L. intracellularis from 12 swine farms by enzyme-linked immunosorbent assay. Materials and method There were taken in study 12 pig farms from west side of Romania with young pigs (35-70 days of age) and fattening (100-150 days of age). In total 61 blood samples from 12 farms were analyzed by using a blocking ELISA by kit Bioscreen Ileitis antibody ELISA (Synbiotics Europe SAS, France). Results and discussions In 10 from 12 studied farms we found one or more positive samples. Our results show that the most affected categories were fattening (100-150 days). From 61 tested samples 31 samples were positive (49,1%), 11 samples had value of percentage of inhibition (PI) between 20 and 30 (18%), and 19 samples were negative (31,1%). The shift of seropositivity to higher age categories (fattening) may be principally connected with the very early antibiotic therapy of swine dysentery in the post-weaning period. In relation to the infection dynamic in the herd demonstrated an increase in the antibodies prevalence in animals from nursery to fattening. Usually seroconversion can be detected between 16 and 24 weeks of age by an increasing percentage of inhibition (PI). A positive test result reflects the exposure of pigs to infection L. intracellularis at least 2 to 3 weeks before (2). The low prevalence in the antibodies detection in weaning pigs suggests a low passive immunity.