The impact of heat stress on imipenem susceptibility in imipenem resistant NTHi
Ontology highlight
ABSTRACT:
INSTRUMENT(S): Illumina HiSeq 2500
ORGANISM(S): Haemophilus influenzae
SUBMITTER: Stefano Leo
PROVIDER: E-MTAB-6237 | biostudies-arrayexpress |
REPOSITORIES: biostudies-arrayexpress
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Project description:Pneumonia is a serious problem worldwide. We recently demonstrated that innate defense mechanisms of the lung are highly inducible against pneumococcal pneumonia. To determine the breadth of protection conferred by stimulation of lung mucosal innate immunity, and to identify cells and signaling pathways activated by this treatment, mice were treated with an aerosolized bacterial lysate, then challenged with lethal doses of bacterial and fungal pathogens. Mice were highly protected against a broad array of Gram-positive, Gram-negative, and Class A bioterror bacterial pathogens, and Aspergillus fumigatus. Protection was associated with rapid pathogen killing within the lungs, and this effect was recapitulated in vitro using a respiratory epithelial cell line. Gene expression analysis of lung tissue showed marked activation of NF-kappaB, Type I and II interferon, and antifungal Card9-Bcl10-Malt1 pathways. Cytokines were the most strongly induced genes, but the inflammatory cytokines TNF and IL-6 were not required for protection. Lung-expressed antimicrobial peptides were also highly upregulated. Taken together, stimulated innate resistance (StIR) appears to occur through the activation of multiple host defense signaling pathways in lung epithelial cells, inducing rapid pathogen killing, and conferring broad protection against virulent bacterial and fungal pathogens. Augmentation of innate antimicrobial defenses of the lungs might have therapeutic value for protection of patients with neutropenia or impaired adaptive immunity against opportunistic pneumonia, and for defense of immunocompetent subjects against a bioterror threat or epidemic respiratory infection. Keywords: differential gene expression; time course; innate immunity; pneumonia; immunocompromised host; lung epithelium Gene expression patterns in mouse lung homogenates were analyzed 2h after exposure to aerosolized PBS (Sham treatment), 2h after exposure to aerosolized NTHi lysate or 4h after exposure to aerosolized NTHi lysate. Each group consisted of six mice.
2010-06-24 | E-GEOD-13740 | biostudies-arrayexpress
Project description:NTHi bacteria or saline were inoculated into the middle ears of mice. Mice were sacrificed at various times to monitor the course of infection. We used Mouse430_2 arrays to profile gene expression in response to bacterial infection RNA extracted at sacrifice
2015-09-01 | E-GEOD-66141 | biostudies-arrayexpress
Project description:Chronic Otitis Media (OM) develops after sustained inflammation and is characterized by secretory middle ear epithelial metaplasia and effusion, most frequently mucoid. Non-typeable Haemophilus influenzae (NTHi), the most common acute OM pathogen, is known to activate inflammation and mucin expression in vitro and in animal models of OM. The goals of this study were to: examine expression profiling epithelial effects of NTHi challenge in murine middle ears. We used microarrays to detail examine the global programme of gene expression underlying epithelial effects of NTHi challenge in murine middle ears during this study. Weekly transtympanic inoculation of Balb/c mice with 300 µg/ml of NTHi lysates vs saline was performed. Bacteria were grown on chocolate agar at 37ºC in 5% CO2 overnight and inoculated in brain heart infusion (BHI) broth supplemented with 3.5 mg of nicotinamide adenine dinucleotide per ml. After overnight incubation, bacteria were subcultured into 5 ml of fresh brain heart infusion (BHI) and upon reaching log phase growth, NTHi were washed and suspended in phosphate-buffered saline (PBS) followed by sonication for lysis. Three transtympanic inoculation of 6 Balb/c mice middle ears (3 animals, 6 ears) with 50 uL of 300 ug/ml of NTHi bacterial lysate and 6 Balb/c mice middle ears (3 animals, 6 ears) with 50 uL of 1X phosphate buffered saline (PBS) were carried out weekly over 4 weeks (injection on days 7, 14, and 21). On day 28, the mice were euthanized and their bullae harvested. Expression microarray analysis was performed at 1 and 7 days. Microarray findings were validated in independent animal samples and in a cultured murine middle ear epithelial cell (mMEEC) line.
2012-11-13 | E-GEOD-40087 | biostudies-arrayexpress
Project description:Nontypeable Haemophilus influenzae (NTHi) is a commensal microorganism of the normal human nasopharyngeal flora, yet also an opportunistic pathogen of the upper and lower respiratory tracts. Changes in gene expression patterns in response to host microenvironments are likely critical for survival. One such system of gene regulation is the ability to carefully regulate iron uptake. A central regulatory system that controls iron uptake, mediated by the ferric uptake regulator Fur, is present in multiple bacteria, including NTHi. Previous work has identified a small RNA, HrrF, that is Fur-regulated in NTHi 86-028NPrpsL.To understand the contribution made by HrrF to gene regulation in NTHi, hrrF was deleted in the NTHi strain 86-028NPrpsLM-bM-^HM-^Ffur. Using RNA-Seq, we identified protein-encoding genes whose expression was repressed or activated by HrrF. These data comprise transcriptional anaylses of an rpsL mutant of 86-028NP, an isogenic fur mutant of 86-028NPrpsL, an isogenic fur mutant of 86-028NPrpsL also containing a full deletion of hrrF, and an isogenic fur mutant of 86-028NPrpsL also containing a deletion of only the 3' portion of hrrF. All strains were grown in defined medium containing 10 M-BM-5g/ml human hemoglobin to mid-log phase. Cells were then harvested and RNA extracted. A total of three biological replicates were generated for these analyses. Analysis of transcriptomes using the Illumina HiSeq 2000 of four strains of nontypeable Haemophilus influenzae which include NTHi 86-028NPrpsL, NTHi 86-028NPrpsLM-bM-^HM-^Ffur, NTHi 86-028NPrpsLM-bM-^HM-^FfurM-bM-^HM-^FhrrF, and NTHi 86-028NPrpsLM-bM-^HM-^FfurM-bM-^HM-^FhrrF3' strains. For each strain three biological replicates were analyzed.
2014-08-26 | E-GEOD-58891 | biostudies-arrayexpress
Project description:Non-typeable Haemophilus influenzae (NTHi) is a common acute otitis media pathogen, with an incidence that is increased by previous antibiotic treatment. NTHi is also an emerging causative agent of other chronic infections in humans, some linked to morbidity, and all of which impose substantial treatment costs. In this study we explore the possibility that antibiotic exposure may stimulate biofilm formation by NTHi bacteria. We discovered that sub-inhibitory concentrations of beta-lactam antibiotic (i.e., amounts that partially inhibit bacterial growth) stimulated the biofilm-forming ability of NTHi strains, an effect that was strain and antibiotic dependent. When exposed to sub-inhibitory concentrations of beta-lactam antibiotics NTHi strains produced tightly packed biofilms with decreased numbers of culturable bacteria but increased biomass. The ratio of protein per unit weight of biofilm decreased as a result of antibiotic exposure. Antibiotic-stimulated biofilms had altered ultrastructure, and genes involved in glycogen production and transporter function were up regulated in response to antibiotic exposure. Down-regulated genes were linked to multiple metabolic processes but not those involved in stress response. Antibiotic-stimulated biofilm bacteria were more resistant to a lethal dose (10M-BM-5g/mL) of cefuroxime. Our results suggest that beta-lactam antibiotic exposure may act as a signaling molecule that promotes transformation into the biofilm phenotype. Loss of viable bacteria, increase in biofilm biomass and decreased protein production coupled with a concomitant up-regulation of genes involved with glycogen production might result in a biofilm of sessile, metabolically inactive bacteria sustained by stored glycogen. These biofilms may protect surviving bacteria from subsequent antibiotic challenges, and act as a reservoir of viable bacteria once antibiotic exposure has ended. 12 samples
2014-06-04 | E-GEOD-58213 | biostudies-arrayexpress
Project description:The impact of heat stress on imipenem susceptibility in imipenem resistant NTHi
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Project description:This study assessed proteomic profile of Candida albicans after serial systemic infection in a murine model. The animals were infected initially by wild-type C. albicans SC5314 (WT) with an inoculum of of 3.5x105 cells via lateral tail vein. Then, five days post-infection, the animals were euthanized and their kidneys were removed, homogenized in lysis buffer, plated on SDA and incubated for 24 h at 35 °C. Colonies recovered from infected kidney were used to prepare inoculum for the subsequent infections as described for WT, totalizing five serial passages (P1-P5) and they were also used to protein extraction. By LC-MS/MS, 479 proteins were identified, with 56 proteins statistically significant in abundance in P1, 29 proteins in P3 and 97 proteins in P4. Regarding biological processes, the majority of proteins were related to carbohydrate metabolism, stress response and amino acid metabolism. The proteins were also categorized according to their potential role in virulence factors such as biofilm production, yeast-to-hyphae transition, phenotypic switching, proteins related to stress response and uncharacterized proteins. Therefore, serial infection associated with proteomic approach enabled to deepen the knowledge about host-pathogen interaction.
2019-07-01 | PXD012944 | Pride
Project description:Acquisition of a new strain of non-typeable Haemophilus influenzae (NTHi) is often associated with exacerbation of chronic obstructive pulmonary disease (COPD). We have previously reported that COPD patients who are homozygous null for SIGLEC14 gene is less susceptible to COPD exacerbation than those who have wild-type allele with functional SIGLEC14 gene. In order to gain insight into the mechanism behind the COPD exacerbation, and to find new clues that may lead to the discovery of objective biomarker of COPD exacerbation, Siglec-14/THP-1 and Siglec-5/THP-1 cell lines, which mimic monocytes from homozygous wild-type and homozygous SIGLEC14-null person, respectively, were incubated with or without NTHi, and their gene expression profiles were compared by using Affymetrix Human Genome U133 Plus 2.0 Array. Four samples (2 cell lines x 2 conditions) were analyzed. No replicates were made.
2014-08-04 | E-GEOD-47929 | biostudies-arrayexpress
Project description:Clostridium acetobutylicum, the endospore-forming anaerobe best known for its ABE (acetone-butanol-ethanol) fermentation, has received renewed attention recently for the biological production of butanol, both for bulk chemical production and as a potential biofuel. With butanol production in mind, most of the recent research on C. acetobutylicum has focused on increasing butanol production, tolerance to butanol, and optimizing it for various substrates. However, an equally important trait, though less understood, is its sporulation program, which it coupled to solvent formation. The model organism for endospore formation is Bacillus subtilis, but significant physiological, metabolic, and genomic differences exist between the two organisms. Despite these differences, the major sporulation-related transcription/sigma factors are conserved between the two species. These transcription/sigma factors are activated in a cascade manner such that Spo0A becomes active first, followed by M-OM-^CF, then M-OM-^CE, then M-OM-^CG, and finally M-OM-^CK. The goal of this study is to determine the regulons of 4 of these transcription/sigma factors (Spo0A, M-OM-^CF, M-OM-^CE, and M-OM-^CG) and compare them to those in B. subtilis. To accomplish this goal, individual mutant strains were created for Spo0A, M-OM-^CF, M-OM-^CE, and M-OM-^CG, in which the transcription/sigma factor is silenced. These mutants were then compared transcriptionally using microarrays to determine the regulon of each transcription/sigma factor. To help avoid false positives, comparisons were made between strains in which the downstream transcription/sigma factor is silenced (e.g., for the Spo0A regulon, the Spo0A mutant was compared against the M-OM-^CF mutant and the M-OM-^CE mutant, since they are both upregulated by Spo0A) rather than just the WT. For each regulon, 4 timepoints were taken, since it is very difficult to synchronize sporulation in C. acetobutylicum cultures, and dye-swaps were prepared for each timepoint. Four transcription/sigma factor regulons were investigated: Spo0A, M-OM-^CF, M-OM-^CE, and M-OM-^CG. For Spo0A, two comparison were made: Spo0A mutant vs M-OM-^CF mutant and Spo0A mutant vs M-OM-^CE mutant. For M-OM-^CF, two comparison were also made: M-OM-^CF mutant vs M-OM-^CE mutant and M-OM-^CF mutant vs M-OM-^CG mutant. Finally for M-OM-^CE and M-OM-^CG, only one comparison for each was made: M-OM-^CE mutant vs M-OM-^CG mutant and M-OM-^CG mutant vs wild-type, respectively. For each comparison, 4 timepoints were analyzed, and dye-swaps were prepared for each timepoint comparison. Timepoints were chosen based on when each transcription/sigma factor was expected to be active, based on a previous study [Jones, SW, et al. Genome Biol. 2008;9(7):R114.].
2011-02-28 | E-GEOD-24103 | biostudies-arrayexpress
Project description:Clostridium acetobutylicum is a Gram positive, endospore forming firmicute that has been known as the model organims for ABE (acetone-butanol-ethanol) fermentation. With its ability to consume a wide variety of substrates, C. acetobutylicum carries out a biphasic ABE fermentation, which consists of the acidogenic growth phase with the formation of butyric acid and acetic acid, followed by the solventogenic stationary phase with the formation of acetone, butanol and ethanol, characterised by the reassimilation of acids. The production butanol is of renewed ineterest both as a potential biofuel and bulk chemical production. Both butanol and butyrate posses toxic characteristic and here, we focus on understanding and modeling the stress response of C. acetobutylicum to one of the two important toxic metabolites: butanol. C. acetobutylicum cultures were grown, three biological replicates, to mid-exponential phase and then stressed with four levels of butanol (0 mM - No stress; 30 mM - Low stress; 60 mM - Medium stress; & 90 mM - High stress). Samples were collected following the stress at 0, 15, 30, 45, 60 and 75 min, post stress. These sampling times, which are of the order of the doubling time of these cells, were meant to capture largely the direct and immediate impact of these stresses on gene expression. The RNA extracted from two biological replicates were used for microarray hybridization foloowing cDNA generationa nd labelling using Agilent 44K arrays, while the third was used for q-RT-PCR validation. For each stress level, 6 time points with 2 biological replicates and dye swaps (Cy3/Cy5) were prepared for comparison. The hybridization was perfomed against an equal amount of oppositely labeled cDNA from common reference pool prepared using equal amounts of labeled cDNA from all four stress levels.
2013-08-20 | E-GEOD-48031 | biostudies-arrayexpress