Antibody responses of swine following infection with Mycoplasma hyopneumoniae, M. hyorhinis, M. hyosynoviae and M. flocculare Joa ˜o Carlos Gomes Neto a,1 , Erin L. Strait a,2 , Matthew Raymond a,3 , Alejandro Ramirez a , F. Chris Minion b, * a Veterinary Diagnostic and Production Animal Medicine, College of Veterinary Medicine, Iowa State University, Ames, IA 50011, United States b Veterinary Microbiology and Preventive Medicine, College of Veterinary Medicine, Iowa State University, Ames, IA 50011, United States 1. Introduction Mycoplasma infections continue to be of concern to swine producers world-wide. While Mycoplasma hyopneu- moniae is the etiologic agent of enzootic pneumonia and a major contributor to porcine respiratory disease complex (Opriessnig et al., 2011; Thacker and Minion, 2012), many Veterinary Microbiology 174 (2014) 163–171 A R T I C L E I N F O Article history: Received 18 February 2014 Received in revised form 6 August 2014 Accepted 8 August 2014 Keywords: Swine mycoplasmas Serology ELISA Oral fluids A B S T R A C T Several mycoplasma species possessing a range of virulence have been described in swine. The most commonly described are Mycoplasma hyopneumoniae, Mycoplasma hyorhinis, Mycoplasma hyosynoviae, and Mycoplasma flocculare. They are ubiquitious in many pig producing areas of the world, and except for M. hyopneumoniae, commercial antibody- based assays are lacking for most of these. Antibody cross-reactivity among these four mycoplasma species is not well characterized. Recently, the use of pen-based oral fluids for herd surveillance is of increasing interest. Thus, this study sought to measure pig antibody responses and the level of cross-reactivity in serum and pen-based oral fluids after challenge with four species of swine mycoplasmas. Four groups of four mycoplasma-free growing pigs were separately inoculated with the different mycoplasma species. Pen- based oral fluids and serum samples were collected weekly until necropsy. Species- specific Tween 20 ELISAs were used to measure antibody responses along with four other commercial M. hyopneumoniae ELISAs. Animals from all groups seroconverted to the challenge species of mycoplasma and no evidence of cross-contamination was observed. A delayed antibody response was seen with all but M. hyorhinis-infected pigs. Cross-reactive IgG responses were detected in M. hyopneumoniae- and M. flocculare-infected animals by the M. hyorhinis Tween 20 ELISA, while sera from M. hyosynoviae and M. flocculare-infected pigs were positive in one commercial assay. In pen-based oral fluids, specific anti-M. hyopneumoniae IgA responses were detected earlier after infection than serum IgG responses. In summary, while some antibody-based assays may have the potential for false positives, evidence of this was observed in the current study. ß 2014 Elsevier B.V. All rights reserved. * Corresponding author. Tel.: +1 515 294 6347; fax: +1 515 294 8500. E-mail address: fcminion@iastate.edu (F.C. Minion). 1 Currently at 352 Food Science Complex, University of Nebraska, Lincoln, NE 68583, United States. 2 Currently at Merck Animal Health, 35500 W. 91st St, DeSoto, KS, 66018, United States. 3 Currently at Department of Pathology, University of Wisconsin, Madison, WI 53715, United States. Contents lists available at ScienceDirect Veterinary Microbiology jo u rn al ho m epag e: ww w.els evier.c o m/lo cat e/vetmic http://dx.doi.org/10.1016/j.vetmic.2014.08.008 0378-1135/ß 2014 Elsevier B.V. All rights reserved.