title: The expression of heterologous MAM-7 in Lactobacillus rhamnosus reduces its intrinsic capacity to inhibit colonization of pathogen Vibrio parahaemolyticus in vitro.
abstract: BACKGROUND
  Vibrio parahaemolyticus (V. parahaemolyticus) is a Gram-negative, halophilic bacterium recognized as one of the most important foodborne pathogen. When ingested, V. parahaemolyticus causes a self-limiting illness (Vibriosis), characterized mainly by watery diarrhoea. Treatment is usually oral rehydration and/or antibiotics in complicated cases. Since 1996, the pathogenic and pandemic V. parahaemolyticus O3:K6 serotype has spread worldwide, increasing the reported number of vibriosis cases. Thus, the design of new strategies for pathogen control and illness prevention is necessary. Lactobacillus sp. grouped Gram positive innocuous bacteria, part of normal intestinal microbiota and usually used as oral vaccines for several diarrheic diseases. Recombinants strains of Lactobacillus (RL) expressing pathogen antigens can be used as part of an anti-adhesion strategy where RL block the pathogen union sites in host cells. Thus, we aimed to express MAM-7 V. parahaemolyticus adhesion protein in Lactobacillus sp. to generate an RL that prevents pathogen colonization.
  
  
  RESULTS
  We cloned the MAM-7 gene from V. parahaemolyticus RIMD 2210633 in Lactobacillus expression vectors. Recombinant strains (Lactobacillus rhamnosus pSEC-MAM7 and L. rhamnosus pCWA-MAM7) adhered to CaCo-2 cells and competed with the pathogen. However, the L. rhamnosus wild type strain showed the best capacity to inhibit pathogen colonization in vitro. In addition, LDH-assay showed that recombinant strains were cytotoxic compared with the wild type isogenic strain.
  
  
  CONCLUSIONS
  MAM-7 expression in lactobacilli reduces the intrinsic inhibitory capacity of L. rhamnosus against V. parahaemolyticus.
authors.affiliation: Escuela de Tecnología Médica, Facultad de Medicina, Universidad Mayor, Camino La Pirámide 5750, Santiago, Huechuraba, Chile. sebastian.beltran.v@gmail.com.|Centro de Genómica y Bioinformática, Facultad de Ciencias, Universidad Mayor, Camino La Pirámide 5750, Santiago, Huechuraba, Chile. sebastian.beltran.v@gmail.com.
authors.forename: Sebastian
authors.initials: S
authors.lastname: Beltran
authors.affiliation: Escuela de Tecnología Médica, Facultad de Medicina, Universidad Mayor, Camino La Pirámide 5750, Santiago, Huechuraba, Chile. cbergmannmunoz@gmail.com.|Centro de Genómica y Bioinformática, Facultad de Ciencias, Universidad Mayor, Camino La Pirámide 5750, Santiago, Huechuraba, Chile. cbergmannmunoz@gmail.com.
authors.forename: Cristian A
authors.initials: CA
authors.lastname: Munoz-Bergmann
authors.affiliation: Centro de Genómica y Bioinformática, Facultad de Ciencias, Universidad Mayor, Camino La Pirámide 5750, Santiago, Huechuraba, Chile. elola.ana@gmail.com.
authors.forename: Ana
authors.initials: A
authors.lastname: Elola-Lopez
authors.affiliation: Centro de Genómica y Bioinformática, Facultad de Ciencias, Universidad Mayor, Camino La Pirámide 5750, Santiago, Huechuraba, Chile. javieranqr@gmail.com.
authors.forename: Javiera
authors.initials: J
authors.lastname: Quintana
authors.affiliation: Centro de Genómica y Bioinformática, Facultad de Ciencias, Universidad Mayor, Camino La Pirámide 5750, Santiago, Huechuraba, Chile. cristopher.segovia@gmail.com.
authors.forename: Cristopher
authors.initials: C
authors.lastname: Segovia
authors.affiliation: Centro de Genómica y Bioinformática, Facultad de Ciencias, Universidad Mayor, Camino La Pirámide 5750, Santiago, Huechuraba, Chile. annette.trombert@umayor.cl.
authors.forename: Annette N
authors.initials: AN
authors.lastname: Trombert
mesh_terms: D018829:Adhesins, Bacterial / Q000032:analysis*; D001422:Bacterial Adhesion / Q000502:physiology*; D018441:Biofilms / Q000254:growth & development; D018938:Caco-2 Cells; D002460:Cell Line; D003602:Cytotoxicity, Immunologic; D004591:Electrophoresis, Polyacrylamide Gel; D015870:Gene Expression; D005840:Gentian Violet; D006801:Humans; D052201:Lacticaseibacillus rhamnosus / Q000502:physiology*; D016133:Polymerase Chain Reaction; D014735:Vibrio Infections / Q000517:prevention & control; D014736:Vibrio parahaemolyticus / Q000254:growth & development / Q000378:metabolism / Q000472:pathogenicity*
chemical_list: D018829:Adhesins, Bacterial; D005840:Gentian Violet