(American Society for Microbiology, 2012) Mainar Jaime, Raúl Carlos; Andrés, S.; Vico, J. P.; San Román Aberasturi, Beatriz; Garrido González, Victoria; Grilló Dolset, María Jesús; IdAB. Instituto de Agrobiotecnología / Agrobioteknologiako Institutua; Gobierno de Navarra / Nafarroako Gobernua, IIQ14064.RI1; Universidad Pública de Navarra / Nafarroako Unibertsitate Publikoa
The ISO 6579:2002/Amd 1:2007 (ISO) standard has been the bacteriological standard method used in the European Union for
the detection of Salmonella spp. in pig mesenteric lymph nodes (MLN), but there are no published estimates of the diagnostic
sensitivity (Se) of the method in this matrix. Here, the Se of the ISO (SeISO) was estimated on 675 samples selected from two populations
with different Salmonella prevalences (14 farms with a ≥20% prevalence and 13 farms with a<20% prevalence) and
through the use of latent-class models in concert with Bayesian inference, assuming 100% ISO specificity, and an invA-based
PCR as the second diagnostic method. The SeISO was estimated to be close to 87%, while the sensitivity of the PCR reached up to
83.6% and its specificity was 97.4%. Interestingly, the bacteriological reanalysis of 33 potential false-negative (PCR-positive)
samples allowed isolation of 19 (57.5%) new Salmonella strains, improving the overall diagnostic accuracy of the bacteriology.
Considering the usual limitations of bacteriology regarding Se, these results support the adequacy of the ISO for the detection of
Salmonella spp. from MLN and also that of the PCR-based method as an alternative or complementary (screening) test for the
diagnosis of pig salmonellosis, particularly considering the cost and time benefits of the molecular procedure.
