A solid-phase competition enzyme-linked immunosorbent assay (ELISA), recombinant VP2 (rVP2) protein, and monoclonal antibody (mAb) were developed for the specific and sensitive detection of porcine parvovirus (PPV) antibodies in pig sera. A total of 1,544 sera samples were collected from breeding pig farms located in the Gyeongsangbuk-do Province in the Republic of Korea. The optimal operating conditions of SC-ELISA were as follows. The concentration of rVP2 proteins coated on the wells was 4 μg/mL, the swine sera were diluted 1:2, and the HRP-conjugated PPV VP2 mAb (9A8 clone) was used at 500 ng/mL. These results suggest that the SC-rVP-ELISA assay may be a valuable alternative to the current diagnostic tools used to detect PPV-specific monoclonal antibodies and broadly monitor PPV infections in domestic pigs at different breeding stages.

Fast, cheap and sufficient serodiagnostic tools needs to be developed for the early detectionof brucellosis. Currently the tools cannot differentiate an active infection from vaccinated, norcan it differentiate other bacterial infections with lipopolysaccharides, especially Yersiniainfections. In this study, we purified recombinant outer membrane protein 10 and 28(rOmp10,rOmp28), and a dipstick assay(indirect or sandwich) was constructed with single(rOmp10 orrOmp28) and combined rOmps(rOmp10 and rOmp28) from Brucella(B.) abortus 544 to evaluatebovine Brucella positive serum collected during the beginning of the Korean outbreak from2006 to 2015. In application with single rOmp, rOmp10(70%; indirect, 92.11%; sandwichdipstick) and rOmp28(72.5%; indirect, 86.84%; sandwich dipstick) had comparable results. Inaddition, results indicated that dipstick with combined rOmps(rOmps10 and rOmp28) weresuperior in detecting positive serum samples, at 85% indirect and 100% sandwich dipstick. Surprisingly, the results were the same in detecting negative results at 97.78% for both singleand combined indirect dipsticks. The dipstick tools with rOmp10 and rOmp28 would be usefulfor a rapid screen method for bovine brucellosis.