The in vitro and in vivo anti-virulence activities of Cinnamomum bejolghota by inhibiting type three secretion system effector proteins of Salmonella

ABSTRACTAlthoughBordetella pertussiscontains and transcribes loci encoding type III secretion system (TTSS) homologues, expression of TTSS-associated proteins has been reported only for non-laboratory-adapted Irish clinical isolates. Here we confirm such a result for clinical isolates obtained from patients treated in Argentinean hospitals. Moreover, we demonstrate that the expression of TTSS-associated proteins is independent both of the year in which the isolate was obtained and of the types of polymorphic alleles for other virulence factors but is dependent on environmental growth conditions. Interestingly, we observed that TTSS-associated protein expression is lost after successivein vitropassages but becomes operative again when bacteria come into contact with the host. Thisin vivoactivation of TTSS expression was observed not only for clinical isolates previously adapted to the laboratory after successivein vitropassages but also for vaccine strains that did not express the systemin vitro. The reversibility of TTSS expression, demonstrated by its switching off-on when the bacterium comes into contact with the host, appears to be an adaptive response of this pathogen.

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Analysis of the Virulence of an Atypical EnteropathogenicEscherichia coliStrainIn VitroandIn Vivoand the Influence of Type Three Secretion System

BioMed Research International ◽

10.1155/2014/797508 ◽

2014 ◽

Vol 2014 ◽

pp. 1-9 ◽

Cited By ~ 3

Author(s):

Suely C. F. Sampaio ◽

Fabiana C. Moreira ◽

Ana M. A. Liberatore ◽

Mônica A. M. Vieira ◽

Terezinha Knobl ◽

...

Keyword(s):

Secretion System ◽

Mesenteric Lymph Nodes ◽

Invasive Potential ◽

Virulence Potential ◽

Type Three Secretion System ◽

Isogenic Mutant Strain ◽

Type Three Secretion

Atypical enteropathogenicEscherichia coli(aEPEC) inject various effectors into intestinal cells through a type three secretion system (T3SS), causing attaching and effacing (A/E) lesions. We investigated the role of T3SS in the ability of the aEPEC 1711-4 strain to interact with enterocytesin vitro(Caco-2 cells) andin vivo(rabbit ileal loops) and to translocate the rat intestinal mucosain vivo. A T3SS isogenic mutant strain was constructed, which showed marked reduction in the ability to associate and invade but not to persist inside Caco-2 cells. After rabbit infection, only aEPEC 1711-4 was detected inside enterocytes at 8 and 24 hours pointing to a T3SS-dependent invasive potentialin vivo. In contrast to aEPEC 1711-4, the T3SS-deficient strain no longer produced A/E lesions or induced macrophage infiltration. We also demonstrated that the ability of aEPEC 1711-4 to translocate through mesenteric lymph nodes to spleen and liver in a rat model depends on a functional T3SS, since a decreased number of T3SS mutant bacteria were recovered from extraintestinal sites. These findings indicate that the full virulence potential of aEPEC 1711-4 depends on a functional T3SS, which contributes to efficient adhesion/invasionin vitroandin vivoand to bacterial translocation to extraintestinal sites.

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Regulation of the Locus of Enterocyte Effacement in Attaching and Effacing Pathogens

Journal of Bacteriology ◽

10.1128/jb.00336-17 ◽

2017 ◽

Vol 200 (2) ◽

Cited By ~ 14

Author(s):

R. Christopher D. Furniss ◽

Abigail Clements

Keyword(s):

Secretion System ◽

Effector Proteins ◽

The Core ◽

Genetic Feature ◽

Gut Epithelium ◽

Type Three Secretion System ◽

Gut Mucosa ◽

Enterocyte Effacement ◽

Type Three Secretion ◽

Complex Regulatory Network

ABSTRACTAttaching and effacing (AE) pathogens colonize the gut mucosa using a type three secretion system (T3SS) and a suite of effector proteins. The locus of enterocyte effacement (LEE) is the defining genetic feature of the AE pathogens, encoding the T3SS and the core effector proteins necessary for pathogenesis. Extensive research has revealed a complex regulatory network that senses and responds to a myriad of host- and microbiota-derived signals in the infected gut to control transcription of the LEE. These signals include microbiota-liberated sugars and metabolites in the gut lumen, molecular oxygen at the gut epithelium, and host hormones. Recent research has revealed that AE pathogens also recognize physical signals, such as attachment to the epithelium, and that the act of effector translocation remodels gene expression in infecting bacteria. In this review, we summarize our knowledge to date and present an integrated view of how chemical, geographical, and physical cues regulate the virulence program of AE pathogens during infection.

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Chemical Inhibitors of the Type Three Secretion System: Disarming Bacterial Pathogens

Antimicrobial Agents and Chemotherapy ◽

10.1128/aac.00975-12 ◽

2012 ◽

Vol 56 (11) ◽

pp. 5433-5441 ◽

Cited By ~ 69

Author(s):

Miles C. Duncan ◽

Roger G. Linington ◽

Victoria Auerbuch

Keyword(s):

Bacterial Infections ◽

Pathogenic Bacteria ◽

Bacterial Pathogens ◽

Secretion System ◽

Effector Proteins ◽

Host Cells ◽

Magic Bullet ◽

Antimicrobial Drugs ◽

Type Three Secretion System ◽

Type Three Secretion

ABSTRACTThe recent and dramatic rise of antibiotic resistance among bacterial pathogens underlies the fear that standard treatments for infectious disease will soon be largely ineffective. Resistance has evolved against nearly every clinically used antibiotic, and in the near future, we may be hard-pressed to treat bacterial infections previously conquered by “magic bullet” drugs. While traditional antibiotics kill or slow bacterial growth, an important emerging strategy to combat pathogens seeks to block the ability of bacteria to harm the host by inhibiting bacterial virulence factors. One such virulence factor, the type three secretion system (T3SS), is found in over two dozen Gram-negative pathogens and functions by injecting effector proteins directly into the cytosol of host cells. Without T3SSs, many pathogenic bacteria are unable to cause disease, making the T3SS an attractive target for novel antimicrobial drugs. Interdisciplinary efforts between chemists and microbiologists have yielded several T3SS inhibitors, including the relatively well-studied salicylidene acylhydrazides. This review highlights the discovery and characterization of T3SS inhibitors in the primary literature over the past 10 years and discusses the future of these drugs as both research tools and a new class of therapeutic agents.

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Salmonella Pathogenicity Island 1 (SPI-1): The Evolution and Stabilization of a Core Genomic Type Three Secretion System

Microorganisms ◽

10.3390/microorganisms8040576 ◽

2020 ◽

Vol 8 (4) ◽

pp. 576

Author(s):

Nicole A. Lerminiaux ◽

Keith D. MacKenzie ◽

Andrew D. S. Cameron

Keyword(s):

Transcription Factors ◽

Pathogenicity Island ◽

Secretion System ◽

Effector Proteins ◽

Gene Promoters ◽

Salmonella Pathogenicity Island ◽

Evolutionary Origins ◽

Type Three Secretion System ◽

History Of ◽

Type Three Secretion

Salmonella Pathogenicity Island 1 (SPI-1) encodes a type three secretion system (T3SS), effector proteins, and associated transcription factors that together enable invasion of epithelial cells in animal intestines. The horizontal acquisition of SPI-1 by the common ancestor of all Salmonella is considered a prime example of how gene islands potentiate the emergence of new pathogens with expanded niche ranges. However, the evolutionary history of SPI-1 has attracted little attention. Here, we apply phylogenetic comparisons across the family Enterobacteriaceae to examine the history of SPI-1, improving the resolution of its boundaries and unique architecture by identifying its composite gene modules. SPI-1 is located between the core genes fhlA and mutS, a hotspot for the gain and loss of horizontally acquired genes. Despite the plasticity of this locus, SPI-1 demonstrates stable residency of many tens of millions of years in a host genome, unlike short-lived homologous T3SS and effector islands including Escherichia ETT2, Yersinia YSA, Pantoea PSI-2, Sodalis SSR2, and Chromobacterium CPI-1. SPI-1 employs a unique series of regulatory switches, starting with the dedicated transcription factors HilC and HilD, and flowing through the central SPI-1 regulator HilA. HilA is shared with other T3SS, but HilC and HilD may have their evolutionary origins in Salmonella. The hilA, hilC, and hilD gene promoters are the most AT-rich DNA in SPI-1, placing them under tight control by the transcriptional repressor H-NS. In all Salmonella lineages, these three promoters resist amelioration towards the genomic average, ensuring strong repression by H-NS. Hence, early development of a robust and well-integrated regulatory network may explain the evolutionary stability of SPI-1 compared to T3SS gene islands in other species.

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CesD2 of Enteropathogenic Escherichia coli Is a Second Chaperone for the Type III Secretion Translocator Protein EspD

Infection and Immunity ◽

10.1128/iai.71.4.2130-2141.2003 ◽

2003 ◽

Vol 71 (4) ◽

pp. 2130-2141 ◽

Cited By ~ 35

Author(s):

Bianca C. Neves ◽

Rosanna Mundy ◽

Liljana Petrovska ◽

Gordon Dougan ◽

Stuart Knutton ◽

...

Keyword(s):

Escherichia Coli ◽

Type Iii Secretion ◽

Type Iii Secretion System ◽

Secretion System ◽

Effector Proteins ◽

Translocator Protein ◽

Type Iii ◽

Genes Encoding

ABSTRACT Enteropathogenic Escherichia coli (EPEC) and enterohemorrhagic E. coli are extracellular pathogens that employ a type III secretion system to export translocator and effector proteins, proteins which facilitates colonization of the mucosal surface of the intestine via formation of attaching and effacing (A/E) lesions. The genes encoding the proteins for A/E lesion formation are located on a pathogenicity island, termed the locus of enterocyte effacement (LEE), which contains eae encoding intimin as well as the type III secretion system and effector genes. Many type III secreted proteins are stabilized and maintained in a secretion-competent conformation in the bacterial cytosol by specific chaperone proteins. Three type III chaperones have been described thus far within the EPEC LEE region: CesD, for the translocator proteins EspB and EspD; CesT, for the effector proteins Tir and Map; and CesF, for EspF. In this study we report the characterization of CesD2 (previously Orf27), a second LEE-encoded chaperone for EspD. We show specific CesD2-EspD protein interaction which appears to be necessary for proper EspD secretion in vitro and pathogenesis in vivo as demonstrated in the A/E-lesion-forming mouse pathogen Citrobacter rodentium.

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Small Molecule Inhibitor of Type Three Secretion System Belonging to a Class 2,4-disubstituted-4H-[1,3,4]-thiadiazine-5-ones Improves Survival and Decreases Bacterial Loads in an AirwayPseudomonas aeruginosaInfection in Mice

BioMed Research International ◽

10.1155/2018/5810767 ◽

2018 ◽

Vol 2018 ◽

pp. 1-13 ◽

Cited By ~ 5

Author(s):

Anna B. Sheremet ◽

Naylia A. Zigangirova ◽

Egor S. Zayakin ◽

Sergei I. Luyksaar ◽

Lydia N. Kapotina ◽

...

Keyword(s):

Small Molecule ◽

Small Molecule Inhibitor ◽

Secretion System ◽

Resistant Bacteria ◽

Lung Pathology ◽

Antibiotic Resistant ◽

Molecule Inhibitor ◽

Type Three Secretion System ◽

Type Three Secretion

Pseudomonas aeruginosais a cause of high mortality in burn, immunocompromised, and surgery patients. High incidence of antibiotic resistance in this pathogen makes the existent therapy inefficient. Type three secretion system (T3SS) is a leading virulence system ofP. aeruginosathat actively suppresses host resistance and enhances the severity of infection. Innovative therapeutic strategies aiming at inhibition of type three secretion system ofP. aeruginosaare highly attractive, as they may reduce the severity of clinical manifestations and improve antibacterial immune responses. They may also represent an attractive therapy for antibiotic-resistant bacteria. Recently our laboratory developed a new small molecule inhibitor belonging to a class 2,4-disubstituted-4H-[1,3,4]-thiadiazine-5-ones, Fluorothiazinon (FT), that effectively suppressed T3SS in chlamydia and salmonellain vitroandin vivo.In this study, we evaluate the activity of FT towards antibiotic-resistant clinical isolates ofP. aeruginosaexpressing T3SS effectors ExoU and ExoS in an airway infection model. We found that FT reduced mortality and bacterial loads and decrease lung pathology and systemic inflammation. In addition, we show that FT inhibits the secretion of ExoT and ExoY, reduced bacteria cytotoxicity, and increased bacteria internalizationin vitro. Overall, FT shows a strong potential as an antibacterial therapy of antibiotic-resistantP. aeruginosainfection.

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Role for the Burkholderia pseudomallei Type Three Secretion System Cluster 1bpscNGene in Virulence

Infection and Immunity ◽

10.1128/iai.01351-10 ◽

2011 ◽

Vol 79 (9) ◽

pp. 3659-3664 ◽

Cited By ~ 23

Author(s):

Tanya D'Cruze ◽

Lan Gong ◽

Puthayalai Treerat ◽

Georg Ramm ◽

John D. Boyce ◽

...

Keyword(s):

Mammalian Cells ◽

Burkholderia Pseudomallei ◽

Gene Clusters ◽

Secretion System ◽

Host Cells ◽

Infection Model ◽

Content Type ◽

Type Three Secretion System ◽

Type Three Secretion

ABSTRACTBurkholderia pseudomallei, the causal agent of melioidosis, employs a number of virulence factors during its infection of mammalian cells. One such factor is the type three secretion system (TTSS), which is proposed to mediate the transport and secretion of bacterial effector molecules directly into host cells. TheB. pseudomalleigenome contains three TTSS gene clusters (designated TTSS1, TTSS2, and TTSS3). Previous research has indicated that neither TTSS1 nor TTSS2 is involved inB. pseudomalleivirulence in a hamster infection model. We have characterized aB. pseudomalleimutant lacking expression of the predicted TTSS1 ATPase encoded bybpscN. This mutant was significantly attenuated for virulence in a respiratory melioidosis mouse model of infection. In addition, analysesin vitroshowed diminished survival and replication in RAW264.7 cells and an increased level of colocalization with the autophagy marker protein LC3 but an unhindered ability to escape from phagosomes. Taken together, these data provide evidence that the TTSS1bpscNgene product plays an important role in the intracellular survival ofB. pseudomalleiand the pathogenesis of murine infection.

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Arginine glycosylation enhances methylglyoxal detoxification

Scientific Reports ◽

10.1038/s41598-021-83437-0 ◽

2021 ◽

Vol 11 (1) ◽

Author(s):

Samir El Qaidi ◽

Nichollas E. Scott ◽

Philip R. Hardwidge

Keyword(s):

Secretion System ◽

Effector Proteins ◽

Glutathione Synthetase ◽

Synthetase Activity ◽

Host Cell Proteins ◽

T3ss Effector ◽

Type Three Secretion System ◽

Arginine Residues ◽

Host Signaling ◽

Type Three Secretion

AbstractType III secretion system effector proteins have primarily been characterized for their interactions with host cell proteins and their ability to disrupt host signaling pathways. We are testing the hypothesis that some effectors are active within the bacterium, where they modulate bacterial signal transduction and physiology. We previously determined that the Citrobacter rodentium effector NleB possesses an intra-bacterial glycosyltransferase activity that increases glutathione synthetase activity to protect the bacterium from oxidative stress. Here we investigated the potential intra-bacterial activities of NleB orthologs in Salmonella enterica and found that SseK1 and SseK3 mediate resistance to methylglyoxal. SseK1 glycosylates specific arginine residues on four proteins involved in methylglyoxal detoxification, namely GloA (R9), GloB (R190), GloC (R160), and YajL (R149). SseK1-mediated Arg-glycosylation of these four proteins significantly enhances their catalytic activity, thus providing another important example of the intra-bacterial activities of type three secretion system effector proteins. These data are also the first demonstration that a Salmonella T3SS effector is active within the bacterium.

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