suisproteins demonstrated in this study will be evaluated in detail as antigens leading to the development of novel serodiagnostic assessments forM

suisproteins demonstrated in this study will be evaluated in detail as antigens leading to the development of novel serodiagnostic assessments forM. ELISA reactions were observed in all infected pigs by 14 days postinfection at the latest and until week 14, the end of the experiments. During acute clinical attacks of eperythrozoonosis, a derailment of the antibody response, determined by decreases in both theM. suisnet ELISA values and the figures ofM. suis-specific immunoblot bands, was accompanied by peaking levels of autoreactive IgG antibodies. In conclusion, theM. suis-specific antigens found to stimulate specific IgG antibodies are potentially useful for the development of novel serodiagnostic assessments. Mycoplasma suis(formerlyEperythrozoon suis) belongs to a group of hemotrophic bacteria which have recently been reclassified within the genusMycoplasma(16,17,18,19,22,29).M. suisis an epicellular hemoparasite that attaches to and causes deformity and damage to porcine erythrocytes (32). The producing disease, traditionally called porcine eperythrozoonosis (PE), has been reported worldwide and is considered a problem of feeder pigs, where it manifests as a febrile acute icteroanemia with low morbidity and high Etifoxine hydrochloride mortality (8). Chronic low-gradeM. suisinfections vary from asymptomatic infections to a range of clinical conditions, including (i) anemia, moderate icterus, and general unthriftiness in newborns, (ii) growth retardation in feeder pigs, and (iii) poor reproductive overall performance in sows (3,8,34). Moreover,M. suisis suspected of suppressing the host’s immune response, leading to an increased proneness to contamination with other infectious brokers of porcine respiratory and enteric diseases (33). The lack of an in vitro cultivation system is the crucial barrier to systematic analyses of the biology ofM. suisas well as the development of useful diagnostic procedures for, e.g., the accurate assessment of the Etifoxine hydrochloride prevalence and significance ofM. suisin pig populations (5,20). Hitherto, laboratory Etifoxine hydrochloride diagnosis ofM. suisusually relies on the microscopic examination of chemically stained peripheral blood smears to directly visualize the microorganisms attached to erythrocytes (15). Recently established PCR assays forM. suiscan detect acutely diseased animals and also asymptomatic carrier pigs and are therefore principally suitable tools for the diagnosis of PE (6,10,15). However, PCR-based methods are still restricted to specialized, well-equipped research laboratories. Methods to detect carrier animals are important for investigating the epidemiology ofM. suisinfections. For these purposes, serological assays are still the methods of choice. A specific and sensitive serological assay based on definedM. suisantigens would allow extensive prevalence studies and be relevant as a matter of routine in diagnostic laboratories. However, attempts to analyze the humoral immune response of pigs toM. suishave been impeded by the poor sensitivities and specificities of current antibody assays, which comprise the match fixation test, the indirect hemagglutination assay, and the enzyme-linked immunosorbent assay (ELISA) (2,12,25,26,27,28). Serodiagnostic assays explained so far have the intrinsic disadvantage of employing complex and undefinedM. suisantigens obtained from the peripheral blood of experimentally infected pigs. Analogous toM. pneumoniaerespiratory contamination in humans as well asM. synoviaeandM. gallisepticuminfections in chickens,M. suisis capable of transiently inducing in swine the expression of cold-reactive antierythrocyte autoantibodies known as chilly agglutinins (CA) (21,24,33). CA are of the immunoglobulin M (IgM) isotype and are directed against carbohydrate antigens expressed around the erythrocyte surface (7,21,33). The biological activities of CA are considered directly responsible for pathogenic effects in PE such as acrocyanosis and pallor and probably also for any suppressive effect on T-lymphocyte blastogenic responses (33). In the blood of experimentally infected pigs, CA andM. suis-specific antibodies appear simultaneously (33). As a result, CA may interfere with the identification ofM. suis-specific serum antibodies by ELISAs, which are still dependent on using blood-derivedM. suisantigens. In these assays, CA bound to stray erythrocyte membrane residues in the blood-derived crude antigen would be targeted by secondary anti-swine immunoglobulin antibody conjugates, thereby maskingM. suis-specific reactivities (25). This fact may limit the validity of serological diagnostic methods. Moreover, the lack of knowledge about theM. suisantigens which are acknowledged SORBS2 during contamination has surely delayed.