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Mikolajczyk-Martinez A, Ugorski M. Unraveling the role of type 1 fimbriae in Salmonella pathogenesis: insights from a comparative analysis of Salmonella Enteritidis and Salmonella Gallinarum. Poult Sci 2023; 102:102833. [PMID: 37356296 PMCID: PMC10404763 DOI: 10.1016/j.psj.2023.102833] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/19/2023] [Revised: 05/21/2023] [Accepted: 05/31/2023] [Indexed: 06/27/2023] Open
Abstract
Significant differences in pathogenicity between Salmonella Enteritidis and Salmonella Gallinarum exist despite the fact that S. Gallinarum is a direct descendant of S. Enteritidis. It was hypothesized that such various properties may be in part the result of differences in structure and functions of type 1 fimbriae (T1Fs). In S. Enteritidis, T1Fs bind to oligomannosidic structures carried by host cell glycoproteins and are called mannose-sensitive T1Fs (MST1F). In S. Gallinarum, T1Fs lost ability to bind such carbohydrate chains, and were named mannose-resistant MRT1Fs (MRT1F). Therefore, the present study was undertaken to evaluate the role of MST1Fs and MRT1Fs in the adhesion, invasion, intracellular survival and cytotoxicity of S. Enteritidis and S. Gallinarum toward chicken intestinal CHIC8-E11cells and macrophage-like HD11 cells. Using mutant strains: S. Enteritidis fimH::kan and S. Gallinarum fimH::kan devoid of T1Fs and in vitro assays the following observations were made. MST1Fs have a significant impact on the chicken cell invasion by S. Enteritidis as MST1F-mediated adhesion facilitates direct and stable contact of bacteria with host cells, in contrast to MRT1Fs expressed by S. Gallinarum. MST1Fs as well as MRT1Fs did not affected intracellular viability of S. Enteritidis and S. Gallinarum. However, absolute numbers of intracellular viable wild-type S. Enteritidis were significantly higher than S. Enteritidis fimH::kan mutant and wild-type S. Gallinarum and S. Gallinarum fimH::kan mutant. These differences, reflecting the numbers of adherent and invading bacteria, underline the importance of MST1Fs in the pathogenicity of S. Enteritidis infections. The cytotoxicity of wild-type S. Enteritidis and its mutant devoid of MST1Fs to HD11 cells was essentially the same, despite the fact that the number of viable intracellular bacteria was significantly lower in the mutated strain. Using HD11 cells with similar number of intracellular wild-type S. Enteritidis and S. Enteritidis fimH::kan mutant, it was found that the lack of MST1Fs did not affect directly the cytotoxicity, suggesting that the increase in cytotoxicity of S. Enteritidis devoid of MST1Fs may be associated with crosstalk between T1Fs and other virulence factors.
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Affiliation(s)
- Agata Mikolajczyk-Martinez
- Department of Biochemistry and Molecular Biology, Faculty of Veterinary Medicine, Wroclaw University of Environmental and Life Sciences, Wroclaw, Poland
| | - Maciej Ugorski
- Department of Biochemistry and Molecular Biology, Faculty of Veterinary Medicine, Wroclaw University of Environmental and Life Sciences, Wroclaw, Poland.
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Betancourt DM, Llana MN, Sarnacki SH, Cerquetti MC, Monzalve LS, Pustovrh MC, Giacomodonato MN. Salmonella Enteritidis foodborne infection induces altered placental morphometrics in the murine model. Placenta 2021; 109:11-18. [PMID: 33915480 DOI: 10.1016/j.placenta.2021.04.004] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 03/16/2021] [Accepted: 04/06/2021] [Indexed: 10/21/2022]
Abstract
INTRODUCTION Salmonella foodborne disease during pregnancy causes a significant fetal loss in domestic livestock and preterm birth, chorioamnionitis and miscarriage in humans. These complications could be associated with alterations in placental structure. This study was aimed to determine how a low dose of Salmonella Enteritidis during late gestation affects placental histomorphometric in mice. METHODS We used a self-limiting enterocolitis murine model. BALB/c pregnant animals received a low dose of Salmonella Enteritidis (3-4 x 102 CFU/mouse) on gestational day (GD) 15. At day 3 post infection bacterial loads, serum cytokines expression and placental histomorphometrics parameters were analyzed. RESULTS We found that a sub-lethal infection with Salmonella induced a significant drop in fetal weight -to-placental weight-ratio and an increase in the placental coefficient. After bacterial inoculation maternal organs were colonized, inducing placental morphometric alterations, including increased placental thickness, reduced surface area, and diminished major and minor diameters. Also, foci of necrosis accompanied by acute leukocyte infiltration in decidual zone, reduction of vascular spaces and vascular congestion in labyrinth zone, were also evident in placentas from infected females on GD 18. Our data shows that placentas from infected mothers are phenotypically different from control ones. Furthermore, expression of IFN-gamma and IL-6 was up regulated in response to Salmonella in maternal serum. DISCUSSION Our findings demonstrate that a low dose of Salmonella during late gestation alters the placental morphometry leading to negative consequences on pregnancy outcome such as significant reduction in fetal body weight.
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Affiliation(s)
- Diana M Betancourt
- Universidad de Buenos Aires (UBA), Consejo Nacional de Investigaciones Científicas y Técnicas (CONICET), Instituto de Investigaciones en Microbiología y Parasitología Médica (IMPaM-UBA-CONICET), Departamento de Microbiología, Parasitología e Inmunología, Facultad de Medicina, UBA, Buenos Aires, Argentina.
| | - Mariángeles Noto Llana
- Universidad de Buenos Aires (UBA), Consejo Nacional de Investigaciones Científicas y Técnicas (CONICET), Instituto de Investigaciones en Microbiología y Parasitología Médica (IMPaM-UBA-CONICET), Departamento de Microbiología, Parasitología e Inmunología, Facultad de Medicina, UBA, Buenos Aires, Argentina.
| | - Sebastián H Sarnacki
- Universidad de Buenos Aires (UBA), Consejo Nacional de Investigaciones Científicas y Técnicas (CONICET), Instituto de Investigaciones en Microbiología y Parasitología Médica (IMPaM-UBA-CONICET), Departamento de Microbiología, Parasitología e Inmunología, Facultad de Medicina, UBA, Buenos Aires, Argentina.
| | - M Cristina Cerquetti
- Universidad de Buenos Aires (UBA), Consejo Nacional de Investigaciones Científicas y Técnicas (CONICET), Instituto de Investigaciones en Microbiología y Parasitología Médica (IMPaM-UBA-CONICET), Departamento de Microbiología, Parasitología e Inmunología, Facultad de Medicina, UBA, Buenos Aires, Argentina.
| | | | - María C Pustovrh
- Departamento de Morfología, Facultad de Salud, Universidad Del Valle, Cali, Colombia.
| | - Mónica N Giacomodonato
- Universidad de Buenos Aires (UBA), Consejo Nacional de Investigaciones Científicas y Técnicas (CONICET), Instituto de Investigaciones en Microbiología y Parasitología Médica (IMPaM-UBA-CONICET), Departamento de Microbiología, Parasitología e Inmunología, Facultad de Medicina, UBA, Buenos Aires, Argentina.
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Mao F, Liu K, Wong NK, Zhang X, Yi W, Xiang Z, Xiao S, Yu Z, Zhang Y. Virulence of Vibrio alginolyticus Accentuates Apoptosis and Immune Rigor in the Oyster Crassostrea hongkongensis. Front Immunol 2021; 12:746017. [PMID: 34621277 PMCID: PMC8490866 DOI: 10.3389/fimmu.2021.746017] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/23/2021] [Accepted: 08/31/2021] [Indexed: 02/05/2023] Open
Abstract
Vibrio species are ubiquitously distributed in marine environments, with important implications for emerging infectious diseases. However, relatively little is known about defensive strategies deployed by hosts against Vibrio pathogens of distinct virulence traits. Being an ecologically relevant host, the oyster Crassostrea hongkongensis can serve as an excellent model for elucidating mechanisms underlying host-Vibrio interactions. We generated a Vibrio alginolyticus mutant strain (V. alginolyticus△vscC ) with attenuated virulence by knocking out the vscC encoding gene, a core component of type III secretion system (T3SS), which led to starkly reduced apoptotic rates in hemocyte hosts compared to the V. alginolyticusWT control. In comparative proteomics, it was revealed that distinct immune responses arose upon encounter with V. alginolyticus strains of different virulence. Quite strikingly, the peroxisomal and apoptotic pathways are activated by V. alginolyticusWT infection, whereas phagocytosis and cell adhesion were enhanced in V. alginolyticus△vscC infection. Results for functional studies further show that V. alginolyticusWT strain stimulated respiratory bursts to produce excess superoxide (O2•-) and hydrogen peroxide (H2O2) in oysters, which induced apoptosis regulated by p53 target protein (p53tp). Simultaneously, a drop in sGC content balanced off cGMP accumulation in hemocytes and repressed the occurrence of apoptosis to a certain extent during V. alginolyticus△vscC infection. We have thus provided the first direct evidence for a mechanistic link between virulence of Vibrio spp. and its immunomodulation effects on apoptosis in the oyster. Collectively, we conclude that adaptive responses in host defenses are partially determined by pathogen virulence, in order to safeguard efficiency and timeliness in bacterial clearance.
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Affiliation(s)
- Fan Mao
- Chinese Academy of Sciences Key Laboratory of Tropical Marine Bio-resources and Ecology and Guangdong Provincial Key Laboratory of Applied Marine Biology, South China Sea Institute of Oceanology, Chinese Academy of Science, Guangzhou, China
- Southern Marine Science and Engineering Guangdong Laboratory (Guangzhou), Guangzhou, China
| | - Kunna Liu
- Chinese Academy of Sciences Key Laboratory of Tropical Marine Bio-resources and Ecology and Guangdong Provincial Key Laboratory of Applied Marine Biology, South China Sea Institute of Oceanology, Chinese Academy of Science, Guangzhou, China
- Southern Marine Science and Engineering Guangdong Laboratory (Guangzhou), Guangzhou, China
- College of Earth and Planetary Sciences, University of Chinese Academy of Sciences, Beijing, China
| | - Nai-Kei Wong
- Chinese Academy of Sciences Key Laboratory of Tropical Marine Bio-resources and Ecology and Guangdong Provincial Key Laboratory of Applied Marine Biology, South China Sea Institute of Oceanology, Chinese Academy of Science, Guangzhou, China
- Department of Pharmacology, Shantou University Medical College, Shantou, China
| | - Xiangyu Zhang
- Chinese Academy of Sciences Key Laboratory of Tropical Marine Bio-resources and Ecology and Guangdong Provincial Key Laboratory of Applied Marine Biology, South China Sea Institute of Oceanology, Chinese Academy of Science, Guangzhou, China
- Southern Marine Science and Engineering Guangdong Laboratory (Guangzhou), Guangzhou, China
- College of Earth and Planetary Sciences, University of Chinese Academy of Sciences, Beijing, China
| | - Wenjie Yi
- Chinese Academy of Sciences Key Laboratory of Tropical Marine Bio-resources and Ecology and Guangdong Provincial Key Laboratory of Applied Marine Biology, South China Sea Institute of Oceanology, Chinese Academy of Science, Guangzhou, China
- Southern Marine Science and Engineering Guangdong Laboratory (Guangzhou), Guangzhou, China
- College of Earth and Planetary Sciences, University of Chinese Academy of Sciences, Beijing, China
| | - Zhiming Xiang
- Chinese Academy of Sciences Key Laboratory of Tropical Marine Bio-resources and Ecology and Guangdong Provincial Key Laboratory of Applied Marine Biology, South China Sea Institute of Oceanology, Chinese Academy of Science, Guangzhou, China
- Southern Marine Science and Engineering Guangdong Laboratory (Guangzhou), Guangzhou, China
| | - Shu Xiao
- Chinese Academy of Sciences Key Laboratory of Tropical Marine Bio-resources and Ecology and Guangdong Provincial Key Laboratory of Applied Marine Biology, South China Sea Institute of Oceanology, Chinese Academy of Science, Guangzhou, China
- Southern Marine Science and Engineering Guangdong Laboratory (Guangzhou), Guangzhou, China
| | - Ziniu Yu
- Chinese Academy of Sciences Key Laboratory of Tropical Marine Bio-resources and Ecology and Guangdong Provincial Key Laboratory of Applied Marine Biology, South China Sea Institute of Oceanology, Chinese Academy of Science, Guangzhou, China
- Southern Marine Science and Engineering Guangdong Laboratory (Guangzhou), Guangzhou, China
- *Correspondence: Yang Zhang, ; Ziniu Yu,
| | - Yang Zhang
- Chinese Academy of Sciences Key Laboratory of Tropical Marine Bio-resources and Ecology and Guangdong Provincial Key Laboratory of Applied Marine Biology, South China Sea Institute of Oceanology, Chinese Academy of Science, Guangzhou, China
- Southern Marine Science and Engineering Guangdong Laboratory (Guangzhou), Guangzhou, China
- *Correspondence: Yang Zhang, ; Ziniu Yu,
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Henard CA, Vázquez-Torres A. Nitric oxide and salmonella pathogenesis. Front Microbiol 2011; 2:84. [PMID: 21833325 PMCID: PMC3153045 DOI: 10.3389/fmicb.2011.00084] [Citation(s) in RCA: 73] [Impact Index Per Article: 5.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/02/2011] [Accepted: 04/08/2011] [Indexed: 12/12/2022] Open
Abstract
Nitric oxide (NO) and its congeners contribute to the innate immune response to Salmonella. This enteric pathogen is exposed to reactive nitrogen species (RNS) in the environment and at different anatomical locations during its infectious cycle in vertebrate hosts. Chemical generation of RNS enhances the gastric barrier to enteropathogenic bacteria, while products of the Salmonella pathogenicity island 1 type III secretion system and Salmonella-associated molecular patterns stimulate transcription of inducible NO synthase (iNOS) by cells of the mononuclear phagocytic cell lineage. The resulting NO, or products that arise from its interactions with oxygen (O2) or iron and low-molecular weight thiols, are preferentially bacteriostatic against Salmonella, while reaction of NO and superoxide (O2−) generates the bactericidal compound peroxynitrite (ONOO−). The anti-Salmonella activity of RNS emanates from the modification of redox active thiols and metal prosthetic groups of key molecular targets of the electron transport chain, central metabolic enzymes, transcription factors, and DNA and DNA-associated proteins. In turn, Salmonella display a plethora of defenses that modulate the delivery of iNOS-containing vesicles to phagosomes, scavenge and detoxify RNS, and repair biomolecules damaged by these toxic species. Traditionally, RNS have been recognized as important mediators of host defense against Salmonella. However, exciting new findings indicate that Salmonella can exploit the RNS produced during the infection to foster virulence. More knowledge of the primary RNS produced in response to Salmonella infection, the bacterial processes affected by these toxic species, and the adaptive bacterial responses that protect Salmonella from nitrosative and oxidative stress associated with NO will increase our understanding of Salmonella pathogenesis. This information may assist in the development of novel therapeutics against this common enteropathogen.
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Affiliation(s)
- Calvin A Henard
- Department of Microbiology, University of Colorado School of Medicine Aurora, CO, USA
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van Ampting MTJ, Schonewille AJ, Vink C, Brummer RJM, van der Meer R, Bovee-Oudenhoven IMJ. Intestinal barrier function in response to abundant or depleted mucosal glutathione in Salmonella-infected rats. BMC PHYSIOLOGY 2009; 9:6. [PMID: 19374741 PMCID: PMC2678068 DOI: 10.1186/1472-6793-9-6] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 07/01/2008] [Accepted: 04/17/2009] [Indexed: 12/24/2022]
Abstract
Background Glutathione, the main antioxidant of intestinal epithelial cells, is suggested to play an important role in gut barrier function and prevention of inflammation-related oxidative damage as induced by acute bacterial infection. Most studies on intestinal glutathione focus on oxidative stress reduction without considering functional disease outcome. Our aim was to determine whether depletion or maintenance of intestinal glutathione changes susceptibility of rats to Salmonella infection and associated inflammation. Rats were fed a control diet or the same diet supplemented with buthionine sulfoximine (BSO; glutathione depletion) or cystine (glutathione maintenance). Inert chromium ethylenediamine-tetraacetic acid (CrEDTA) was added to the diets to quantify intestinal permeability. At day 4 after oral gavage with Salmonella enteritidis (or saline for non-infected controls), Salmonella translocation was determined by culturing extra-intestinal organs. Liver and ileal mucosa were collected for analyses of glutathione, inflammation markers and oxidative damage. Faeces was collected to quantify diarrhoea. Results Glutathione depletion aggravated ileal inflammation after infection as indicated by increased levels of mucosal myeloperoxidase and interleukin-1β. Remarkably, intestinal permeability and Salmonella translocation were not increased. Cystine supplementation maintained glutathione in the intestinal mucosa but inflammation and oxidative damage were not diminished. Nevertheless, cystine reduced intestinal permeability and Salmonella translocation. Conclusion Despite increased infection-induced mucosal inflammation upon glutathione depletion, this tripeptide does not play a role in intestinal permeability, bacterial translocation and diarrhoea. On the other hand, cystine enhances gut barrier function by a mechanism unlikely to be related to glutathione.
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Salmonella enterica serovar Enteritidis dam mutant induces low NOS-2 and COX-2 expression in macrophages via attenuation of MAPK and NF-kappaB pathways. Microbes Infect 2008; 10:1431-9. [PMID: 18801455 DOI: 10.1016/j.micinf.2008.08.008] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/05/2008] [Revised: 07/28/2008] [Accepted: 08/08/2008] [Indexed: 01/10/2023]
Abstract
Although dam mutants of Salmonella have been proposed as live vaccines, their capacity to trigger cell inflammatory cascades has not been fully elucidated. We investigated in detail the ability of Salmonella enterica dam mutant to activate the signalling pathways of the inflammatory response in RAW 264.7 cells. Apoptosis in macrophages treated with Salmonella dam mutant was low. Similarly, the expression of both NOS-2 and COX-2 and subsequently the production of NO and PGE(2) was significantly reduced. Also, Salmonella dam mutant induced an attenuated activation of the inflammatory signalling pathway as indicated by the reduced degradation of IkappaBalpha and IkappaBbeta and the low IkappaBalpha phosphorylation found. In addition, translocation of p65 to the nucleus was notably impaired and the amount of phosphorylated p44, p42 and p38 MAPKs was clearly reduced in extracts from dam-infected macrophages. These results indicate that the lack of ERK and p38 phosphorylation at the proper time in dam-infected cells notably reduces the engagement of subsequent signalling pathways involved in the full activation of NF-kappaB in response to infection. Taken together, these results suggest that Salmonella activation of both signalling cascades in the inflammatory response is a mechanism requiring Dam protein participation.
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Alam MS, Zaki MH, Sawa T, Islam S, Ahmed KA, Fujii S, Okamoto T, Akaike T. Nitric oxide produced in Peyer's patches exhibits antiapoptotic activity contributing to an antimicrobial effect in murine salmonellosis. Microbiol Immunol 2008; 52:197-208. [DOI: 10.1111/j.1348-0421.2008.00030.x] [Citation(s) in RCA: 24] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/23/2022]
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Aita K, Irie H, Tanuma Y, Toida S, Okuma Y, Mori S, Shiga J. Apoptosis in murine lymphoid organs following intraperitoneal administration of dimethyl sulfoxide (DMSO). Exp Mol Pathol 2005; 79:265-71. [PMID: 16154562 DOI: 10.1016/j.yexmp.2005.07.001] [Citation(s) in RCA: 28] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/15/2005] [Accepted: 07/29/2005] [Indexed: 11/19/2022]
Abstract
A significant increase in lymphocyte apoptosis was detected by the TUNEL method in the thymus, spleen, and Peyer's patches (PP) following intraperitoneal (i.p.) administration of dimethyl sulfoxide (DMSO) (treatment, n = 47; control, n = 8). Interestingly, administration of low doses of DMSO caused apoptosis in only the PP, and suggested that i.p. administration of DMSO induced apoptosis for each lymphoid organ in a dose dependent manner. Moreover, in the early stage during the apoptotic change, a characteristic localization of lymphocytes undergoing apoptosis was observed. Briefly, early apoptosis occurred predominantly in the cortical mid-zone of the thymus, white pulp of the spleen, and germinal centers of PP. With increased time following administration, however, lymphocytes throughout lymphoid tissues, independent of characteristic localization during the early stage, seemed to undergo apoptosis, resulting in the severe loss of lymphocytes. In fact, the relative spleen weight significantly decreased at 24 h following DMSO administration (n = 7; P < 0.001 versus 8 control mice). Taken together, these results showed for the first time that the in vivo administration of DMSO to mice caused apoptosis in lymphoid organs, and also demonstrated that the apoptotic behavior varied between different lymphoid organs.
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Affiliation(s)
- Kiyoshi Aita
- Department of Pathology, Teikyo University School of Medicine, Kaga 2-11-1, Itabashi-ku, Tokyo 173-8605, Japan.
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Abstract
This review discusses the role that nitric oxide (NO) and its congeners play on various stages in the pathophysiology of Escherichia coli and Salmonella infections, with special emphasis on the regulatory pathways that lead to high NO synthesis, the role of reactive nitrogen species (RNS) in host resistance, and the bacterial molecular targets and defense mechanisms that protect enteric bacteria against the nitrosative stress encountered in diverse host anatomical sites. In general, NO can react directly with prosthetic groups containing transition metal centers, with other radicals, or with sulfhydryl groups in the presence of an electron acceptor. Binding to iron complexes is probably the best characterized direct reaction of NO in biological systems. The targets of RNS are numerous. RNS can facilitate oxidative modifications including lipid peroxidation, hydroxylation, and DNA base and protein oxidation. In addition, RNS can inflict nitrosative stress through the nitrosation of amines and sulfhydryls. Numerous vital bacterial molecules can be targeted by NO. It is therefore not surprising that enteropathogenic bacteria are armed with a number of sensors to coordinate the protective response to nitrosative stress, along with an assortment of antinitrosative defenses that detoxify, repair, or avoid the deleterious effects of RNS encountered within the host. NO and NO-derived RNS play important roles in innate immunity to Salmonella and E. coli. Enzymatic NO production by NO synthases can be enhanced by microbial and other inflammatory stimuli and it exerts direct antimicrobial actions as well as immunomodulatory and vasoregulatory effects.
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Giacomodonato MN, Sarnacki SH, Caccuri RL, Sordelli DO, Cerquetti MC. Host response to a dam mutant of Salmonella enterica serovar enteritidis with a temperature-sensitive phenotype. Infect Immun 2004; 72:5498-501. [PMID: 15322053 PMCID: PMC517460 DOI: 10.1128/iai.72.9.5498-5501.2004] [Citation(s) in RCA: 14] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
The temperature-sensitive dam mutant strain of Salmonella enterica serovar Enteritidis SD1 is highly attenuated and induces innate and protective immunity in mice. SD1 activates NF-kappaB and induces gamma interferon secretion. Early interaction of the SD1 mutant with intestinal epithelial cells was associated with ruffling of enterocytes. Invading bacteria were found inside Peyer's patches after inoculation.
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Affiliation(s)
- Mónica N Giacomodonato
- Centro de Estudios Farmacológicos y Botánicoas (CEFYBO-CONICET), Buenos Aires, Argentina
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Abstract
The Gram-negative pathogen Salmonella enterica can survive and replicate within a variety of mammalian cells. Regardless of the cell type, internalized bacteria survive and replicate within the Salmonella-containing vacuole, the biogenesis of which is dependent on bacterially encoded virulence factors. In particular, Type III secretion systems translocate bacterial effector proteins into the eukaryotic cell where they can specifically interact with a variety of targets. Salmonella has two distinct Type III secretion systems that are believed to have completely different functions. The SPI2 system is induced intracellularly and is required for intracellular survival in macrophages; it plays no role in invasion but is categorized as being required for Salmonella-containing vacuole biogenesis. In contrast, the SPI1 Type III secretion system is induced extracellularly and is essential for invasion of nonphagocytic cells. Its role in post-invasion processes has not been well studied. Recent studies indicate that Salmonella-containing vacuole biogenesis may be more dependent on SPI1 than previously believed. Other non-SPI2 virulence factors and the host cell itself may play critical roles in determining the intracellular environment of this facultative intracellular pathogen. In this review we discuss the recent advances in determining the mechanisms by which Salmonella regulate Salmonella-containing vacuole biogenesis and the implications of these findings.
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Affiliation(s)
- Leigh A Knodler
- Host-Parasite Interactions Section, Laboratory of Intracellular Parasites, National Institutes of Allergy and Infectious Diseases/NIH, Rocky Mountain Laboratories, Hamilton, MT 59840, USA
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Giacomodonato MN, Goren NB, Sordelli DO, Vaccaro MI, Grasso DH, Ropolo AJ, Cerquetti MC. Involvement of intestinal inducible nitric oxide synthase (iNOS) in the early stages of murine salmonellosis. FEMS Microbiol Lett 2003; 223:231-8. [PMID: 12829292 DOI: 10.1016/s0378-1097(03)00385-9] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022] Open
Abstract
Local induction of inducible nitric oxide synthase (iNOS) and apoptosis was examined in the intestine of mice infected with virulent Salmonella enterica serovar Enteritidis 5694 (S. enteritidis) and its attenuated derivative mutant E/1/3. Both, intestinal iNOS mRNA expression and iNOS activity showed a peak at 4 h only in animals receiving the virulent S. enteritidis. Aminoguanidine treatment abrogated intestinal epithelial damage produced by virulent S. enteritidis and diminished apoptosis at the tips of the villi. Unlike the virulent strain, mutant E/1/3 induced massive iNOS expression in Peyer's patches, these findings may be related to its protective capacity. Our results suggest that intestinal iNOS participates in the early response to intestinal infection and that the final effect depends on the nature of the insult.
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Affiliation(s)
- Mónica N Giacomodonato
- Centro de Estudios Farmacológicos y Botánicos (CEFYBO-CONICET), Serrano 669, 1414 Buenos Aires, Argentina
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