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Salmonella porins

Javier Fernández, Beatriz Guerra, M Rosario Rodicio
Non-typhoidal serovars of Salmonella enterica (NTS) are a leading cause of food-borne disease in animals and humans worldwide. Like other zoonotic bacteria, NTS have the potential to act as reservoirs and vehicles for the transmission of antimicrobial drug resistance in different settings. Of particular concern is the resistance to critical "last resort" antimicrobials, such as carbapenems. In contrast to other Enterobacteriaceae (e.g., Klebsiella pneumoniae , Escherichia coli , and Enterobacter , which are major nosocomial pathogens affecting debilitated and immunocompromised patients), carbapenem resistance is still very rare in NTS...
April 8, 2018: Veterinary Sciences
Anna E Schager, C Coral Dominguez-Medina, Francesca Necchi, Francesca Micoli, Yun Shan Goh, Margaret Goodall, Adriana Flores-Langarica, Saeeda Bobat, Charlotte N L Cook, Melissa Arcuri, Arianna Marini, Lloyd D W King, Faye C Morris, Graham Anderson, Kai-Michael Toellner, Ian R Henderson, Constantino López-Macías, Calman A MacLennan, Adam F Cunningham
Antibodies acquired after vaccination or natural infection with Gram-negative bacteria, such as invasive Salmonella enterica serovar Typhimurium, can protect against disease. Immunization with naturally shed outer membrane vesicles from Gram-negative bacteria is being studied for its potential to protect against many infections, since antigens within vesicles maintain their natural conformation and orientation. Shedding can be enhanced through genetic modification, and the resulting particles, generalized modules for membrane antigens (GMMA), not only offer potential as vaccines but also can facilitate the study of B-cell responses to bacterial antigens...
March 6, 2018: MBio
Yang Zhang, Coral Dominguez-Medina, Nicola J Cumley, Jennifer N Heath, Sarah J Essex, Saeeda Bobat, Anna Schager, Margaret Goodall, Sven Kracker, Christopher D Buckley, Robin C May, Robert A Kingsley, Calman A MacLennan, Constantino López-Macías, Adam F Cunningham, Kai-Michael Toellner
In mice, the IgG subclass induced after Ag encounter can reflect the nature of the Ag. Th2 Ags such as alum-precipitated proteins and helminths induce IgG1, whereas Th1 Ags, such as Salmonella Typhimurium, predominantly induce IgG2a. The contribution of different IgG isotypes to protection against bacteria such as S. Typhimurium is unclear, although as IgG2a is induced by natural infection, it is assumed this isotype is important. Previously, we have shown that purified S. Typhimurium porins including outer membrane protein OmpD, which induce both IgG1 and IgG2a in mice, provide protection to S...
December 15, 2017: Journal of Immunology: Official Journal of the American Association of Immunologists
Stefani C Kary, Joshua R K Yoneda, Stephen C Olshefsky, Laura A Stewart, Steven B West, Andrew D S Cameron
Fluoroquinolone antibiotics are prescribed for the treatment of Salmonella enterica infections, but resistance to this family of antibiotics is growing. Here we report that loss of the global regulatory protein cyclic AMP (cAMP) receptor protein (CRP) or its allosteric effector, cAMP, reduces susceptibility to fluoroquinolones. A Δcrp mutation was synergistic with the primary fluoroquinolone resistance allele gyrA83, thus able to contribute to clinically relevant resistance. Decreased susceptibility to fluoroquinolones could be partly explained by decreased expression of the outer membrane porin genes ompA and ompF with a concomitant increase in the expression of the ciprofloxacin resistance efflux pump gene acrB in Δcrp cells...
November 2017: Antimicrobial Agents and Chemotherapy
Marisol Pérez-Toledo, Nuriban Valero-Pacheco, Rodolfo Pastelin-Palacios, Cristina Gil-Cruz, Christian Perez-Shibayama, Mario A Moreno-Eutimio, Ingeborg Becker, Sonia Mayra Pérez-Tapia, Lourdes Arriaga-Pizano, Adam F Cunningham, Armando Isibasi, Laura C Bonifaz, Constantino López-Macías
Several microbial components, such as bacterial DNA and flagellin, have been used as experimental vaccine adjuvants because of their inherent capacity to efficiently activate innate immune responses. Likewise, our previous work has shown that the major Salmonella Typhi (S. Typhi) outer membrane proteins OmpC and OmpF (porins) are highly immunogenic protective antigens that efficiently stimulate innate and adaptive immune responses in the absence of exogenous adjuvants. Moreover, S. Typhi porins induce the expression of costimulatory molecules on antigen-presenting cells through toll-like receptor canonical signaling pathways...
2017: Frontiers in Immunology
Fuguo Liu, Xiaoqian Tang, Xiuzhen Sheng, Jing Xing, Wenbin Zhan
Outer membrane protein C is a porin that resides in the outer membrane, and it has been identified as an antigenic protein in many bacteria, such as Escherichia coli, Salmonella typhi, Aeromonas hydrophila and Edwardsiella tarda. In the present work, we aimed at evaluating the immune protective potential of E. tarda OmpC as a DNA vaccine. For this purpose, a recombinant DNA plasmid encoding OmpC (pCG-OmpC) gene was constructed and its vaccine potential was analyzed in a flounder (Paralichthys olivaceus) model...
March 2017: Microbial Pathogenesis
Madhuranayaki Thulasingam, Subha Damodharan, Gopal Madhana Vigneshwari, Eswari P J Pandaranayaka, Luke Elizabeth Hanna, Ramakrishnan Usha, Sankaran Krishnaswamy
Porins form trimers in the outer membrane and help transport nutrients and waste products across the bacterial cell membrane. Porin loops are suitable candidates as display systems due to their high immunogenicity and presentation at the bacterial cell surface. In this study, Salmonella typhi porins (OmpC and OmpF) engineered with the Kennedy peptide from gp41 of HIV were characterised. The chimeric OmpC carrying the Kennedy peptide in loop7 did not trimerise, whereas the chimeric OmpF with the epitope in loop5 formed trimers and also was recognised by the antibodies in the HIV patient serum...
April 2017: Proteins
Hongmei Jiao, Hui Yang, Dan Zhao, Li He, Jin Chen, Guocai Li
Human health has been seriously endangered by highly prevalent salmonellosis and multidrug-resistant Salmonella strains. Current vaccines suffer from variable immune-protective effects, so more effective ones are needed to control Salmonella infection : Bacterial ghosts have been produced by the expression of lysis gene E from bacteriophage PhiX174 and can be filled with considerable exogenous substances such as DNA or drugs as a novel platform. In this study, Salmonella enteritidis (SE) ghosts were developed and loaded with Neisseria gonorrhoeae porin B (porB) to construct a novel inactive vaccine...
November 2016: FEMS Microbiology Letters
Marisol Pérez-Toledo, Paola A Martínez-Amador, Rodolfo Pastelin-Palacios, Armando Isibasi, Adam F Cunningham, Constantino López-Macías
In the present work, we report, for the first time, on the purification of the Salmonella Typhimurium OmpD porin. We assessed the integrity and purity of the protein and evaluated the immunogenicity of the protein and its ability to induce antibody without exogenous adjuvant. We observed that 10 μg OmpD induced high antibody levels of IgM and IgG, which were maintained for more than 260 days after immunization. Immunization with OmpD induced multiple IgG antibody isotypes including IgG1, IgG2a, IgG2b, and IgG3 subclasses...
October 2016: Gaceta Médica de México
Kathrin S Fröhlich, Katharina Haneke, Kai Papenfort, Jörg Vogel
Model enteric bacteria such as Escherichia coli and Salmonella enterica express hundreds of small non-coding RNAs (sRNAs), targets for most of which are yet unknown. Some sRNAs are remarkably well conserved, indicating that they serve cellular functions that go beyond the necessities of a single species. One of these 'core sRNAs' of largely unknown function is the abundant ∼100-nucleotide SdsR sRNA which is transcribed by the general stress σ-factor, σ(S) and accumulates in stationary phase. In Salmonella, SdsR was known to inhibit the synthesis of the species-specific porin, OmpD...
December 1, 2016: Nucleic Acids Research
Juan Manuel Carreño, Christian Perez-Shibayama, Cristina Gil-Cruz, Andrea Printz, Rodolfo Pastelin, Armando Isibasi, Dominic Chariatte, Yutaka Tanoue, Constantino Lopez-Macias, Bruno Gander, Burkhard Ludewig
Salmonella (S.) enterica infections are an important global health problem with more than 20 million individuals suffering from enteric fever annually and more than 200,000 lethal cases per year. Although enteric fever can be treated appropriately with antibiotics, an increasing number of antibiotic resistant Salmonella strains is detected. While two vaccines against typhoid fever are currently on the market, their availability in subtropical endemic areas is limited because these products need to be kept in uninterrupted cold chains...
July 29, 2016: Vaccine
Natalia Cernicchiaro, Samuel E Ives, Thomas S Edrington, Tiruvoor G Nagaraja, David G Renter
The efficacy of a Salmonella vaccine for reducing fecal shedding of Salmonella during the finishing period and lymph node (LN) carriage at harvest was investigated in commercial feedlot cattle. The study was designed as a pen-level randomized complete block with two treatment groups, a Salmonella Newport siderophore receptor and porin proteins-based vaccine (VAC) and a nonvaccinated control (CON). Cattle were randomly allocated into 24 pens within 12 blocks based on the time of allocation. Twenty to 25 fecal pats were collected from each of the study pen floors once a month from June to August 2013...
September 2016: Foodborne Pathogens and Disease
Howard T H Saw, Mark A Webber, Shazad Mushtaq, Neil Woodford, Laura J V Piddock
OBJECTIVES: The objective of this study was to study the contribution of the multidrug resistance AcrAB-TolC efflux system to carbapenem resistance in carbapenemase-producing Enterobacteriaceae and the impact of the efflux inhibitor PABN on this resistance. METHODS: Klebsiella pneumoniae, Escherichia coli, Salmonella enterica serovar Typhimurium and their corresponding AcrAB-TolC mutants, each carrying carbapenemase-carrying plasmids (pKpQIL-UK with blaKPC and pNDM-HK with blaNDM), were tested for their susceptibility to six β-lactam antibiotics according to the BSAC agar dilution method...
June 2016: Journal of Antimicrobial Chemotherapy
Jitendra Kumar, Vijay K Sharma, Dheeraj K Singh, Ashish Mishra, Surendra K Gond, Satish K Verma, Anuj Kumar, Ravindra Nath Kharwar
The endophytic Streptomyces coelicolor strain AZRA 37 was isolated from the surface sterilized root of Azadirachta indica A. Juss., commonly known as neem plant in India. Since only a few reports are available regarding epigenetic modulations of microbial entities, S. coelicolor was treated with different concentrations of 5-azacytidine for this purpose and evaluated for its antibacterial potential against five human pathogenic bacteria (Aeromonas hydrophila IMS/GN11, Enterococcus faecalis IMS/GN7, Salmonella typhi MTCC 3216, Shigella flexneri ATCC 12022 and Staphylococcus aureus ATCC 25923)...
2016: PloS One
Thatyane M Nobre, Michael W Martynowycz, Konstantin Andreev, Ivan Kuzmenko, Hiroshi Nikaido, David Gidalevitz
Small hydrophilic antibiotics traverse the outer membrane of Gram-negative bacteria through porin channels. Large lipophilic agents traverse the outer membrane through its bilayer, containing a majority of lipopolysaccharides in its outer leaflet. Genes controlled by the two-component regulatory system PhoPQ modify lipopolysaccharides. We isolate lipopolysaccharides from isogenic mutants of Salmonella sp., one lacking the modification, the other fully modified. These lipopolysaccharides were reconstituted as monolayers at the air-water interface, and their properties, as well as their interaction with a large lipophilic drug, novobiocin, was studied...
December 15, 2015: Biophysical Journal
Brigitta Kurenbach, Delphine Marjoshi, Carlos F Amábile-Cuevas, Gayle C Ferguson, William Godsoe, Paddy Gibson, Jack A Heinemann
UNLABELLED: Biocides, such as herbicides, are routinely tested for toxicity but not for sublethal effects on microbes. Many biocides are known to induce an adaptive multiple-antibiotic resistance phenotype. This can be due to either an increase in the expression of efflux pumps, a reduced synthesis of outer membrane porins, or both. Exposures of Escherichia coli and Salmonella enterica serovar Typhimurium to commercial formulations of three herbicides-dicamba (Kamba), 2,4-dichlorophenoxyacetic acid (2,4-D), and glyphosate (Roundup)-were found to induce a changed response to antibiotics...
March 24, 2015: MBio
Yi-Lin Tsai, Min-Cheng Wang, Po-Ren Hsueh, Ming-Che Liu, Rouh-Mei Hu, Yue-Jin Wu, Shwu-Jen Liaw
Proteus mirabilis isolates commonly have decreased susceptibility to imipenem. Previously, we found P. mirabilis hfq mutant was more resistant to imipenem and an outer membrane protein (OMP) could be involved. Therefore, we investigated the role of this OMP in carbapenem susceptibility. By SDS-PAGE we found this OMP (named ImpR) was increased in hfq mutant and LC-MS/MS revealed it to be the homologue of Salmonella YbfM, which is a porin for chitobiose and subject to MicM (a small RNA) regulation. We demonstrated that ImpR overexpression resulted in increased carbapenem MICs in the laboratory strain and clinical isolates...
2015: PloS One
Daniel Aguayo, Nicolás Pacheco, Eduardo H Morales, Bernardo Collao, Roberto Luraschi, Carolina Cabezas, Paulina Calderón, Fernando González-Nilo, Fernando Gil, Iván L Calderón, Claudia P Saavedra
OmpD is the major Salmonella enterica serovar Typhimurium (S. Typhimurium) porin and mediates hydrogen peroxide (H2O2) influx. The results described herein extend this finding to hypochlorous acid (HOCl), another reactive oxygen species that is also part of the oxidative burst generated by the phagosome. S. Typhimurium cells lacking OmpD show decreased HOCl influx, and OmpD-reconstituted proteoliposomes show an increase in the uptake of the toxic compound. To understand this physiologically relevant process, we investigated the role of key OmpD residues in H2O2 and NaOCl transport...
February 15, 2015: Archives of Biochemistry and Biophysics
Antonio Galiana, Laura Sánchez-Guillén, Juan Carlos Rodríguez, Rosa Cremades, Migue Santibañez, Rafaela Ferrari, Montserrat Ruiz-García, Pilar López, Gloria Royo
Introduction. The marA, soxS, ramA, acrB and ompF genes have been studied in order to characterize mechanisms of AcrAB-TolC active efflux pumps and membrane permeability alterations that reduce fluoroquinolones susceptibility in Salmonella spp. Methods. Mutations in marA, soxS, ramA, acrB and ompF genes were detected, as well as their expression levels in presence and absence of ciprofloxacin, calculating the level of change between them by qPCR. Data were analysed by using SPSS 19.0. Results. No mutations in these genes were found, but both AcrAB-TolC regulatory genes and structural acrB gene expression were affected by ciprofloxacin in both mutant strains and wild type bacterial strains (WT)...
December 2014: Revista Española de Quimioterapia: Publicación Oficial de la Sociedad Española de Quimioterapia
Saeeda Bobat, Matthew Darby, Dunja Mrdjen, Charlotte Cook, Erin Logan, Jennifer Auret, Elizabeth Jones, Corinna Schnoeller, Adriana Flores-Langarica, Ewan A Ross, Alykhan Vira, Constantino López-Macías, Ian R Henderson, James Alexander, Frank Brombacher, William G Horsnell, Adam F Cunningham
BACKGROUND: The impact of exposure to multiple pathogens concurrently or consecutively on immune function is unclear. Here, immune responses induced by combinations of the bacterium Salmonella Typhimurium (STm) and the helminth Nippostrongylus brasiliensis (Nb), which causes a murine hookworm infection and an experimental porin protein vaccine against STm, were examined. METHODOLOGY/PRINCIPAL FINDINGS: Mice infected with both STm and Nb induced similar numbers of Th1 and Th2 lymphocytes compared with singly infected mice, as determined by flow cytometry, although lower levels of secreted Th2, but not Th1 cytokines were detected by ELISA after re-stimulation of splenocytes...
December 2014: PLoS Neglected Tropical Diseases
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