Detection of Porcine reproductive and respiratory syndrome virus (PRRSV) antibodies in oral fluid specimens using a commercial PRRSV serum antibody enzyme-linked immunosorbent assay

Abstract

The purpose of the present study was to evaluate the diagnostic performance of a commercial serum antibody enzyme-linked immunosorbent assay (ELISA) modified to detect anti– Porcine reproductive and respiratory syndrome virus (PRRSV) antibodies in pen-based oral fluid specimens. Experimental and field oral fluid samples of defined status in reference to exposure of swine with PRRSV were used to derive the kinetics of detectable concentrations of antibody against PRRSV. Immunoglobulin (Ig)M and IgA were readily detected in oral fluid specimens from populations in which PRRSV infection was synchronized among all individuals but not in samples collected in commecial herds. In contrast, IgG was readily detected at diagnostically useful levels in both experimental and field samples for up to 126 days. Estimates of the IgG oral fluid ELISA performance were based on results from testing positive oral fluid samples ( n = 492) from experimentally inoculated pigs ( n = 251) and field samples ( n = 241) and negative oral fluid samples ( n = 367) from experimentally inoculated pigs ( n = 84) and field samples ( n = 283). Receiver operating characteristic analysis estimated the diagnostic sensitivity and specificity of the assay as 94.7% (95% confidence interval [CI]: 92.4, 96.5) and 100% (95% CI: 99.0, 100.0), respectively, at a sample-to-positive ratio cutoff of ≥0.40. The results of the study suggest that the IgG oral fluid ELISA can provide efficient, cost-effective PRRSV monitoring in commercial herds and PRRSV surveillance in elimination programs.

Probability of detecting Porcine reproductive and respiratory syndrome virus infection using pen-based swine oral fluid specimens as a function of within-pen prevalence

“…The first oral fluid-based antibody ELISA for swine, the PRRSV oral fluid Ig ELISA, was described in 2012. 6 Prior to this, the majority of swine oral fluid specimens were tested by PCR because antibody assays for pathogens of swine had not been adapted to the oral fluid matrix. The use of oral fluid PCRs was supported by research demonstrating their application to the oral fluid matrix.…”

“…[5][6][7][9][10][11][12] While PCR-based assays are useful for detecting the immediate circulation of pathogens, antibody-based assays are informative regarding herd immunity and the history of an infection in the population. Because both assays reflect different phases of infection, the best test can be selected to serve the need.…”

Antibody responses of swine following infection with Mycoplasma hyopneumoniae, M. hyorhinis, M. hyosynoviae and M. flocculare

“…The ELISA protocol has been described (Bereiter et al, 1990). For testing of pen-based oral fluids samples, 150 ml of oral fluid was mixed with 150 ml of Tris buffered saline, and then 200 ml of this final solution was added to the plate (Kittawornrat et al, 2012). One positive (serum from animals of known status) and one negative control sera plus a well containing PBS were run on each plate as quality controls.…”

“…2.5.2. Pen-based oral fluids Samples were collected from M. hyopneumoniae-, M. hyorhinis-and M. flocculare-infected animals as described (Kittawornrat et al, 2012) at time points listed in Table 2. A 5/8 00 cotton rope was cut to length so that the end was shoulder-high to the animals and hung in the center of the pen.…”

Oral fluid as material for non-invasive antibiotics detection in pigs

“…Płyn ustny znalazł zastosowanie jako materiał diagnostyczny do wykrywania zespołu rozrodczo-oddechowego świń (PRRS), cirkowirusa świń typu 2 (PCV2), grypy świń oraz infekcji Mycoplasma hyopneumoniae, Haemophilus parasuis, Mycoplasma hyorhinis (1, 15, 17, 25). Do badania płynu ustnego świń wykorzystywane są właściwe testy serologiczne oraz PCR, odpowiednio zaadaptowane i zoptymalizowane (15). Badania nad pleuropneumonią, podczas których pobierano próbki płynu ustnego od świń zakażonych Actinobacillus pleuropnneumoniae eksperymentalnie i naturalnie, wykazały, że testem ELISA IgA wykrywano w płynie ustnym zanim przeciwciała pojawiły się w surowicy, ale rejestrowano jednocześnie szybszy spadek ich stę-żenia w porównaniu do krwi.…”