Serovar-Dependent Gene Regulation and Antimicrobial Tolerance in Streptococcus suis Biofilms

[EN] Introduction: Streptococcus suis is a zoonotic pathogen of great relevance to the swine industry, characterized by high genetic diversity and multiple serovars (SVs) with varying clinical prevalence. Biofilm formation represents a key factor in its virulence, antimicrobial resistance and infect...

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Detalles Bibliográficos
Autores: Delgado García, Mario, Arenas Fernández, Carmen, Mencía Ares, Óscar, Manzanares Vigo, Lucía, Pastor Calonge, Ana Isabel, González Fernández, Alba, Gutiérrez Martín, César Bernardo, Martínez Martínez, Sonia
Tipo de recurso: artículo
Estado:Versión publicada
Fecha de publicación:2025
País:España
Institución:Universidad de León
Repositorio:BULERIA. Repositorio Institucional de la Universidad de León
OAI Identifier:oai:dnet:buleria_____::df3ee1bf2d0172993f22920245b08d67
Acceso en línea:https://www.mdpi.com/2079-6382/14/12/1224
https://hdl.handle.net/10612/28200
Access Level:acceso abierto
Palabra clave:Sanidad animal
Veterinaria
Antibiotic
Biofilm
Gene expression
Serovar
Resistance
RNA
RT-qPCR
Streptococcus suis
3109 Ciencias Veterinarias
Descripción
Sumario:[EN] Introduction: Streptococcus suis is a zoonotic pathogen of great relevance to the swine industry, characterized by high genetic diversity and multiple serovars (SVs) with varying clinical prevalence. Biofilm formation represents a key factor in its virulence, antimicrobial resistance and infection persistence. Methods: We integrated gene expression profiling of biofilm-associated genes by RT-qPCR and antimicrobial susceptibility in planktonic and mature biofilm against five antibiotics in S. suis field isolates belonging to SV1, SV2, SV7 and SV9. Results: Expression of quorum sensing and adhesion genes (luxS, fbps, sadP and srtA) was significantly higher in SV2, the poorest biofilm formers, and inversely correlated with biofilm biomass, suggesting these factors act during early biofilm establishment. Correlation analysis indicated coordinated regulation among genes involved in quorum sensing, adhesion and capsule synthesis. Antimicrobial susceptibility testing revealed a high frequency of non-wild type phenotypes in planktonic cells for tetracycline, erythromycin and clindamycin (>80%), while ampicillin and ciprofloxacin were less frequent. Mature biofilms exhibited a significant increase in antimicrobial tolerance for all antibiotics tested, with SV2 showing the greatest susceptibility. Conclusions: These data highlight serovar-specific biofilm regulation patterns and enhanced drug tolerance in established S. suis biofilms