170088 20260318155254.0 doi 10.1016/j.vetmic.2026.110964 sideral 148652 ART-2026-148652 eng Saralegui, Luis Universidad de Zaragoza Engineering bright and genetically stable fluorescent Streptococcus suis strains for functional in vitro and in vivo applications 2026 Streptococcus suis is a major cause of streptococcal infections in pigs and an emerging zoonotic pathogen, resulting in substantial economic losses in the swine production industry. The limited efficacy of current vaccine strategies and the rise in antimicrobial resistance have intensified efforts to investigate the biology and pathogenesis of the microorganism as a basis for developing alternative control strategies. In this work, we engineered a genetically stable S. suis strain producing a superfolder green fluorescent protein that may serve to study this pathogen in a variety of in vitro and in vivo assays. Multiple S. suis strains from different genetic backgrounds were successfully transformed, exhibiting strong and stable fluorescence without compromising bacterial growth. Fluorescence intensity remained consistent over 15 serial passages in culture without the need for antibiotic selection, supporting its suitability for long-term experiments. The fluorescent strains were nicely distinguishable by fluorescence microscopy and enabled the detailed study of various biological aspects, including biofilm formation, interactions with eukaryotic cells, and differential growth. In murine infection models, the engineered strains caused streptococcal disease, unlike unencapsulated mutant derivatives, and were detected in internal organs via fluorescence microscopy. Altogether, this work provides a valuable tool for advancing research into S. suis. Access copy available to the general public Unrestricted info:eu-repo/grantAgreement/ES/MICINN/PID2023-146823OB-I00 info:eu-repo/semantics/openAccess by https://creativecommons.org/licenses/by/4.0/deed.es info:eu-repo/semantics/article info:eu-repo/semantics/publishedVersion García, Carla Universidad de Zaragoza Jurado, Paula Bosch, Camila van Setten, Marga Wessel, Vloet Bermúdez, Rocío Marín, Clara (orcid)0000-0002-1974-9025 Arenas, Jesús Universidad de Zaragoza (orcid)0000-0002-8134-0693 1009 773 Universidad de Zaragoza Dpto. Patología Animal Área Sanidad Animal 316 (2026), 110964 [12 pp.] Vet. microbiol. Veterinary Microbiology 0378-1135 7199980 http://zaguan.unizar.es/record/170088/files/texto_completo.pdf Versión publicada 2554922 http://zaguan.unizar.es/record/170088/files/texto_completo.jpg?subformat=icon icon Versión publicada oai:zaguan.unizar.es:170088 articulos driver 2026-03-18-13:51:58 ARTICLE