Molecular typing of Streptococcus suis isolates from Iberian pigs: A comparison with isolates from common intensively-reared commercial pig breeds
Artículo de investigación publicado en The Veterinary Journal
1 de diciembre de 2014
The Iberian pig (IP) is a traditional Spanish breed variety of the domestic pig (Sus scrofa domesticus) with high economic importance because of the value of the dry-cured products in national and international markets. The genetic characteristics of tonsillar and clinical Streptococcus suis isolates from the IP maintained under extensive or intensive management conditions were investigated. S. suis isolates from IP pigs were compared with S. suis isolates from intensively-farmed pigs of common breeds (CBP). S. suis was isolated from 48.4% of the IP tonsils examined, indicating wide distribution among IP pigs. Serotypes 1 (9.4%), 2 (8.6%) and 9 (7%) were the most commonly found, although a high percentage of S. suis isolates were not typeable by coagglutination testing. No significant differences in carrier rates or serotype diversity were observed between management systems, indicating that intensive farming does not influence S. suis colonisation. Both pulsed-field gel electrophoresis and multiple-locus variable number tandem repeat analysis showed a serotype-based distribution of S. suis IP isolates. Serotypes 1 and 2 S. suis isolates were grouped in the same cluster, whereas isolates of serotypes 9 and 7 were assigned to another cluster. All clinical and most tonsillar serotype 2 IP isolates were assigned to sequence type 1 (ST1) and exhibited the virulence genotype mrp+/epf+/sly+, indicating a high distribution of this genetic lineage among IP as well as a population of serotype 2 common to IPs and CBPs. The only clinical isolate of serotype 9 from IP was assigned to ST123, a sequence type associated with clinical isolates in CBPs in Spain
Sanchez V., Fernandez-Garayzabal JF., Barcena C., Briones V., Dominguez L., Gottschalk M. y Vela AI..
 | Departamento de Sanidad Animal. Facultad de Veterinaria. Universidad Complutense (UCM). |
| Servicio de Identificación y Caracterización Microbiana (ICM). Centro de Vigilancia Sanitaria Veterinaria (VISAVET). Universidad Complutense (UCM). |
 | Centro de Investigación en Sanidad Animal (CISA). Instituto Nacional de Investigación y Tecnología Agraria y Alimentaria (INIA). |
| Faculté de Médicine Vétérinaire. Université de Montréal (UM). | |
