{"status":"ok","message-type":"work","message-version":"1.0.0","message":{"indexed":{"date-parts":[[2026,9,29]],"date-time":"2026-09-29T09:11:47Z","timestamp":1790673107909,"version":"4.1.0"},"reference-count":42,"publisher":"MDPI AG","issue":"2","license":[{"start":{"date-parts":[[2016,4,19]],"date-time":"2016-04-19T00:00:00Z","timestamp":1461024000000},"content-version":"vor","delay-in-days":0,"URL":"https:\/\/creativecommons.org\/licenses\/by\/4.0\/"}],"content-domain":{"domain":[],"crossmark-restriction":false},"short-container-title":["Pathogens"],"abstract":"<jats:p>Streptococcus suis is an important swine pathogen and emerging zoonotic agent worldwide causing meningitis, endocarditis, arthritis and septicemia. Among the 29 serotypes identified to date, serotype 2 is mostly isolated from diseased pigs. Although several virulence mechanisms have been characterized in S. suis, the pathogenesis of S. suis infections remains only partially understood. This study focuses on the response of S. suis P1\/7 to sub-inhibitory concentrations of amoxicillin. First, capsule expression was monitored by qRT-PCR when S. suis was cultivated in the presence of amoxicillin. Then, the pro-inflammatory potential of S. suis P1\/7 culture supernatants or whole cells conditioned with amoxicillin was evaluated by monitoring the activation of the NF-\u03baB pathway in monocytes and quantifying pro-inflammatory cytokines secreted by macrophages. It was found that amoxicillin decreased capsule expression in S. suis. Moreover, conditioning the bacterium with sub-inhibitory concentrations of amoxicillin caused an increased activation of the NF-\u03baB pathway in monocytes following exposure to bacterial culture supernatants and to a lesser extent to whole bacterial cells. This was associated with an increased secretion of pro-inflammatory cytokines (CXCL8, IL-6, IL-1\u03b2) by macrophages. This study identified a new mechanism by which S. suis may increase its inflammatory potential in the presence of sub-inhibitory concentrations of amoxicillin, a cell wall-active antibiotic, thus challenging its use for preventive treatments or as growth factor.<\/jats:p>","DOI":"10.3390\/pathogens5020037","type":"journal-article","created":{"date-parts":[[2016,4,19]],"date-time":"2016-04-19T06:32:53Z","timestamp":1461047573000},"page":"37","update-policy":"https:\/\/doi.org\/10.3390\/mdpi_crossmark_policy","source":"Crossref","is-referenced-by-count":12,"title":["Impact of Sub-Inhibitory Concentrations of Amoxicillin on Streptococcus suis Capsule Gene Expression and Inflammatory Potential"],"prefix":"10.3390","volume":"5","author":[{"given":"Bruno","family":"Haas","sequence":"first","affiliation":[{"name":"Groupe de Recherche en \u00c9cologie Buccale (GREB), Facult\u00e9 de M\u00e9decine Dentaire, Universit\u00e9 Laval, Quebec City, QC G1V 0A6, Canada"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Daniel","family":"Grenier","sequence":"additional","affiliation":[{"name":"Groupe de Recherche en \u00c9cologie Buccale (GREB), Facult\u00e9 de M\u00e9decine Dentaire, Universit\u00e9 Laval, Quebec City, QC G1V 0A6, Canada"},{"name":"Centre de Recherche en Infectiologie Porcine et Avicole (CRIPA), Fonds de Recherche du Qu\u00e9bec\u2014Nature et Technologies (FRQNT), Saint-Hyacinthe, QC J2S 2M2, Canada"}],"role":[{"vocabulary":"crossref","role":"author"}]}],"member":"1968","published-online":{"date-parts":[[2016,4,19]]},"reference":[{"key":"ref_1","unstructured":"Karriger, L.R.A., Schwartz, K.J., Stevenson, G., and Zimmerman, J. 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