Piglets from vaccinated sows had higher IgG levels at early time points and subsequently were colonized later and to a lower degree than piglets from non-vaccinated ones. The variability of H. parasuis isolates was investigated by 2 genotyping methods: enterobacterial repetitive intergenic consensus (ERIC)-PCR and multilocus sequence typing (MLST). A high turnover of strains was found in both groups of piglets, with few strains found on more than one sampling occasion. We found a higher number of H. parasuis strains (16 strains) within a given farm than previously thought. Overall, more H. parasuis diversity was found in piglets from non-vaccinated sows than in those from vaccinated sows.
These results indicate that vaccination of sows in a farm delays the colonization of piglets and reduces the carriage and heterogeneity of H. parasuis strains.
Cerdà-Cuéllar M, Naranjo JF, Verge A, Nofrarías M, Cortey M, Olvera A, Segalés J, Aragon V. Sow vaccination modulates the colonization of piglets by Haemophilus parasuis. Vet Microbiol. 2010 Apr 14. [Epub ahead of print].