{"status":"ok","message-type":"work","message-version":"1.0.0","message":{"indexed":{"date-parts":[[2026,8,27]],"date-time":"2026-08-27T00:33:55Z","timestamp":1787790835388,"version":"build-2784847793"},"reference-count":60,"publisher":"MDPI AG","issue":"4","license":[{"start":{"date-parts":[[2020,12,14]],"date-time":"2020-12-14T00:00:00Z","timestamp":1607904000000},"content-version":"vor","delay-in-days":0,"URL":"https:\/\/creativecommons.org\/licenses\/by\/4.0\/"}],"funder":[{"name":"Programa de Apoyos a Proyectos de Investigacion e Innovacion Tecnologica, UNAM","award":["PAPIIT: IN222806, IN222913, IN216316"],"award-info":[{"award-number":["PAPIIT: IN222806, IN222913, IN216316"]}]}],"content-domain":{"domain":[],"crossmark-restriction":false},"short-container-title":["Vaccines"],"abstract":"<jats:p>The wide variety of pathogenic Leptospira serovars and the weak protection offered by the available vaccines encourage the search for protective immunogens against leptospirosis. We found that the secretin GspD of the type II secretion system (T2S) of Leptospira interrogans serovar Canicola was highly conserved amongst pathogenic serovars and was expressed in vivo during infection, as shown by immunohistochemistry. Convalescent sera of hamsters, dogs, and cows showed the presence of IgG antibodies, recognizing a recombinant version of this protein expressed in Escherichia coli (rGspDLC) in Western blot assays. In a pilot vaccination study, a group of eight hamsters was immunized on days zero and 14 with 50 \u00b5g of rGspDLC mixed with Freund\u2019s incomplete adjuvant (FIA). On day 28 of the study, 1,000 LD50 (Lethal Dose 50%) of a virulent strain of Leptospira interrogans serovar Canicola (LOCaS46) were inoculated by an intraoral submucosal route (IOSM). Seventy-five percent protection against disease (p = 0.017573, Fisher\u2019s exact test) and 50% protection against infection were observed in this group of vaccinated hamsters. In contrast, 85% of non-vaccinated hamsters died six to nine days after the challenge. These results suggest the potential usefulness of the T2S secretin GspD of Leptospira as a protective recombinant vaccine against leptospirosis.<\/jats:p>","DOI":"10.3390\/vaccines8040759","type":"journal-article","created":{"date-parts":[[2020,12,13]],"date-time":"2020-12-13T23:39:36Z","timestamp":1607902776000},"page":"759","update-policy":"https:\/\/doi.org\/10.3390\/mdpi_crossmark_policy","source":"Crossref","is-referenced-by-count":8,"title":["GspD, The Type II Secretion System Secretin of Leptospira, Protects Hamsters against Lethal Infection with a Virulent L. interrogans Isolate"],"prefix":"10.3390","volume":"8","author":[{"given":"Samantha Paulina","family":"Llanos Salinas","sequence":"first","affiliation":[{"name":"Teaching, Research and Extension Center for Animal Production in High Plateau, School of Veterinary Medicine and Zootechnics, National Autonomous University of Mexico, Queretaro 76795, Mexico"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Luz Olivia","family":"Castillo S\u00e1nchez","sequence":"additional","affiliation":[{"name":"Unidad Acad\u00e9mica de Medicina Veterinaria y Zootecnia, Universidad Aut\u00f3noma de Nayarit, Tepic 63155, Mexico"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Giselle","family":"Casta\u00f1eda Miranda","sequence":"additional","affiliation":[{"name":"Teaching, Research and Extension Center for Animal Production in High Plateau, School of Veterinary Medicine and Zootechnics, National Autonomous University of Mexico, Queretaro 76795, Mexico"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Ernesto Armando","family":"Rodr\u00edguez Reyes","sequence":"additional","affiliation":[{"name":"Divisi\u00f3n de Estudios de Posgrado, Facultad de Medicina, Universidad Nacional Aut\u00f3noma de M\u00e9xico, Coyoac\u00e1n 04510, Mexico"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Liliana","family":"Ordo\u00f1ez 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