RNA-Seq analysis of the T3SA regulon in Shigella flexneri reveals two new chromosomal genes upregulated in the on-state

Publication date: Available online 21 March 2019Source: MethodsAuthor(s): Navoun Silué, Endrei Marcantonio, F-X Campbell-ValoisAbstractShigella spp. are enterobacteria that invade human colonic mucosal cells using their Type Three Secretion Apparatus (T3SA). Shigella spp. possess a large plasmid that encodes most of its virulence factors and has been the focus of seminal work that defined the T3SA regulon. Thus, a global assessment of the transcriptional response regulated by the T3SA has been lacking. Herein we used RNA-Seq to identify genes that are differentially expressed when the T3SA is active (on-state) versus inactive (off-state). The quality of the RNA-Seq dataset was validated by its correlation with a prior microarray study. Using novel insights about the expression of non-coding regions, bioinformatic tools and experimentations, we demonstrated the existence of six operons and evidence that ipaH2.5 is a pseudogene. In addition, 86 chromosomal genes were downregulated in the on-state including several non-coding transcripts corresponding to short antisense RNA embedded in the 16S and 23S RNA genes, and 40 coding transcripts, whose cognate proteins were highly connected at the genetic and biochemical levels. Finally, we identified two novel chromosomal genes dubbed gem1 and gem3, which were upregulated in the on-state similarly to genes belonging to the T3SA regulon. The latter findings were validated on biological triplicates by droplet digital PCR. To our k...
Source: Methods - Category: Molecular Biology Source Type: research

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ConclusionsHMOs in maternal milk are among important factors shaping GI tract microbiota composition in one ‐month old breastfed infants. Infant's ability to metabolise different HMOs strongly correlate with faecal microbiota composition, and with phylotypes within generaBifidobacterium, Bacteroides andLactobacillus.This article is protected by copyright. All rights reserved
Source: Molecular Nutrition and Food Research - Category: Food Science Authors: Tags: Research Article Source Type: research
In this study, we identified 37 genus-level core bacteria from feces of 101 healthy mice with different ages, sexes, and mouse strains in three previous studies. They collectively represented nearly half of the total sequences, and predominantly included carbohydrate- and amino acids-metabolizing bacteria and immunomodulatory bacteria. Among them, Anaerostipes indwelt the gut of all healthy mice. Co-abundance analysis showed that these core genera were clustered into five groups (Group C1–C5), which were ecologically related. For example, the abundances of Group C2 including probiotics Bifidobacterium and Lactobacill...
Source: Frontiers in Microbiology - Category: Microbiology Source Type: research
Conclusion This study confirms the in vitro antibacterial activity of BIOCITRO® against Gram-negative and Gram-positive bacteria. For most of the strains, the product reached the bactericidal effect at the same concentration of the bacteriostatic effect and maximum difference between MIC and MBC was two dilution steps. The less susceptible species of the study were S. enterica ssp. enterica and E. coli with MBC90 values of 256 and 128 μg/mL, respectively, while the most susceptible was C. perfringens with MBC90 of 16 μg/mL. After short exposition time to the product, the significant effect over the viability of ...
Source: Frontiers in Microbiology - Category: Microbiology Source Type: research
In conclusion, we unraveled the secretome of G. adiacens, an oral bacterium well-documented in infective endocarditis, but also recently shown to be involved in oral infections. Importantly, the secretome of G. adiacens comprised of a large number of putative virulence factors. Of particular importance is the finding that the G. adiacens secretome comprised of a number of “moonlighting” proteins, which in other species are shown to enhance bacterial colonization and virulence through their multifunctional roles (Pavkova et al., 2017; Graf et al., 2019). Thus, our results provide a basis for investigating the ro...
Source: Frontiers in cellular and infection microbiology - Category: Microbiology Source Type: research
AbstractShigella type III effector OspF, a nuclear translocation protein, has been showed to have an essential role inShigella flexneri infection and virulence; OspF increases inflammation and induces bacterial invasion by down-regulating MAPK kinases pathway. Nevertheless, the exact mechanisms underlying its nuclear translocation and signaling remain unclear. In the following study, we constructed series of OspF truncated mutants to identify the OspF nuclear localization signals which mapped to the amino acids 209 –239. Moreover, we found that this sequence was essential to bind the canonical nuclear import adaptor ...
Source: World Journal of Microbiology and Biotechnology - Category: Microbiology Source Type: research
This study aimed to evaluate anti-Shigella flexneri activities of Crinum jagus water/ethanol extract. In vitro activities were assayed by disc diffusion and agar dilution methods and in vivo section on Shigella flexneri-induced diarrhea in rats. This was done by oral administration of 9 X 108 CFU of Shigella flexneri to rats that were treated twice daily with Crinum jagus water/ethanol extract for seven consecutive days. Ciprofloxacin was used as positive control. Daily Shigella flexneri load was evaluated. After one treatment week, animals were then sacrificed and interleukins (IL-2 and INF-γ), immunoglobulins (IgA ...
Source: Methods of Information in Medicine - Category: Information Technology Authors: Tags: Evid Based Complement Alternat Med Source Type: research
In this study, eight phages were sequentially separated from sewage (Table 2). Phages vB_EcoS_IME18 (IME18), vB_EcoS_IME253 (IME253), vB_EcoM_IME281 (IME281), vB_EcoM_IME338 (IME338), vB_EcoM_IME339 (IME339), vB_EcoM_IME340 (IME340), vB_EcoM_IME341 (IME341), and vB_EcoS_IME347 (IME347) formed clear, bright plaques on soft agar plates (Supplementary Figure S2). TEM imaging showed that phages IME281 (Figure 1), IME339 (Figure 2), IME340 (Figure 3), and IME341 (Figure 4) had a prolate head and a tail with a contractile sheath. The elongated icosahedral head was ∼100 nm long and 80 nm wide, while the tail tube was ∼100...
Source: Frontiers in Microbiology - Category: Microbiology Source Type: research
Conclusion: Some Lactobacillus strains exhibit anti-CRE activity, which suggests potential applications for controlling or preventing CRE colonization or infection. Introduction Although Enterobacteriaceae are normal flora of the human intestinal system, they are also common pathogens causing human infections in the setting of both community-acquired and healthcare-associated infections (Hsueh et al., 2010; Toh et al., 2012; Lai et al., 2014; Jean et al., 2016). In this era of widespread antibiotic resistance, Enterobacteriaceae are no exception. Recently, the emergence of carbapenem-resistant Enterobacteriaceae (C...
Source: Frontiers in Microbiology - Category: Microbiology Source Type: research
We report a 1-year, multisite, age-stratified, matched case-control study following on to the GEMS study. Six sites (Bamako, Mali; Manhiça, Mozambique; Basse, The Gambia; Mirzapur, Bangladesh; Kolkata, India; and Bin Qasim Town, Karachi, Pakistan) participated in this study. Children aged 0–59 months at each site who sought care at a sentinel hospital or health centre during a 12-month period were screened for diarrhoea. New (onset after ≥7 diarrhoea-free days) and acute (onset within the previous 7 days) episodes of diarrhoea in children who had sunken eyes, whose skin lost turgor, who received intravenous...
Source: The Lancet Global Health - Category: International Medicine & Public Health Source Type: research
Giuseppe Ristagno1*, Francesca Fumagalli1, Barbara Bottazzi2, Alberto Mantovani2,3,4, Davide Olivari1, Deborah Novelli1 and Roberto Latini1 1Department of Cardiovascular Research, Mario Negri Institute for Pharmacological Research IRCCS, Milan, Italy 2Humanitas Clinical and Research Center-IRCCS, Milan, Italy 3Humanitas University, Milan, Italy 4The William Harvey Research Institute, Queen Mary University of London, London, United Kingdom The long pentraxin PTX3 is a member of the pentraxin family produced locally by stromal and myeloid cells in response to proinflammatory signals and microbial moieties. The p...
Source: Frontiers in Immunology - Category: Allergy & Immunology Source Type: research
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