Phosphatidylinositol (3,5)-bisphosphate machinery regulates neurite thickness through neuron-specific endosomal protein NSG1/NEEP21.

Phosphatidylinositol (3,5)-bisphosphate [PtdIns(3,5)P2] is a critical signaling phospholipid involved in endolysosome homeostasis. It is synthesized by a protein complex composed of PIKfyve, Vac14, and Fig4. Defects in PtdIns(3,5)P2 synthesis underlie a number of human neurological disorders, including Charcot-Marie-Tooth disease, child onset progressive dystonia, and others. However, neuron-specific functions of PtdIns(3,5)P2 remain less understood. Here, we show that PtdIns(3,5)P2 pathway is required to maintain neurite thickness. Suppression of PIKfyve activities using either pharmacological inhibitors or RNA silencing resulted in decreased neurite thickness. We further find that the regulation of neurite thickness by PtdIns(3,5)P2 is mediated by NSG1/NEEP21, a neuron-specific endosomal protein. Knockdown of NSG1 expression also led to thinner neurites. mCherry-tagged NSG1 colocalized and interacted with proteins in the PtdIns(3,5)P2 machinery. Perturbation of PtdIns(3,5)P2 dynamics by overexpressing Fig4 or a PtdIns(3,5)P2-binding domain resulted in mislocalization of NSG1 to nonendosomal locations, and suppressing PtdIns(3,5)P2 synthesis resulted in an accumulation of NSG1 in EEA1-positive early endosomes. Importantly, overexpression of NSG1 rescued neurite thinning in PtdIns(3,5)P2-deficient CAD neurons and primary cortical neurons. Our study uncovered the role of PtdIns(3,5)P2 in the morphogenesis of neurons, which revealed a novel aspect of the pathogenesis of PtdIns(3,5)P2-related neuropathies. We also identified NSG1 as an important downstream protein of PtdIns(3,5)P2, which may provide a novel therapeutic target in neurological diseases.

Intestinal dysbiosis exacerbates susceptibility to the anti-NMDA receptor encephalitis-like phenotype by changing blood brain barrier permeability and immune homeostasis.

Changes in the intestinal microbiota have been observed in patients with anti-N-methyl-D-aspartate receptor encephalitis (NMDARE). However, whether and how the intestinal microbiota is involved in the pathogenesis of NMDARE susceptibility needs to be demonstrated. Here, we first showed that germ-free (GF) mice that underwent fecal microbiota transplantation (FMT) from NMDARE patients, whose fecal microbiota exhibited low short-chain fatty acid content, decreased abundance of Lachnospiraceae, and increased abundance of Verrucomicrobiota, Akkermansia, Parabacteroides, Oscillospirales, showed significant behavioral deficits. Then, these FMT mice were actively immunized with an amino terminal domain peptide from the GluN1 subunit (GluN1356-385) to mimic the pathogenic process of NMDARE. We found that FMT mice showed an increased susceptibility to an encephalitis-like phenotype characterized by more clinical symptoms, greater pentazole (PTZ)-induced susceptibility to seizures, and higher levels of T2 weighted image (T2WI) hyperintensities following immunization. Furthermore, mice with dysbiotic microbiota had impaired blood-brain barrier integrity and a proinflammatory condition. In NMDARE-microbiota recipient mice, the levels of Evan's blue (EB) dye extravasation increased, ZO-1 and claudin-5 expression decreased, and the levels of proinflammatory cytokines (IL-1, IL-6, IL-17, TNF-α and LPS) increased. Finally, significant brain inflammation, mainly in hippocampal and cortical regions, with modest neuroinflammation, immune cell infiltration, and reduced expression of NMDA receptors were observed in NMDARE microbiota recipient mice following immunization. Overall, our findings demonstrated that intestinal dysbiosis increased NMDARE susceptibility, suggesting a new target for limiting the occurrence of the severe phenotype of NMDARE.

Constructing an Ultra-Rapid Nanoconfinement-Enhanced Fluorescence Clinical Detection Platform by Using Machine Learning and Tunable DNA Xerogel "Probe".

Low mass transfer efficiency and unavoidable matrix effects seriously limit the development of rapid and accurate determination of biosensing systems. Herein, we have successfully constructed an ultra-rapid nanoconfinement-enhanced fluorescence clinical detection platform based on machine learning (ML) and DNA xerogel "probe", which was performed by detecting neutrophil gelatinase-associated lipocalin (NGAL, protein biomarker of acute kidney injury). By regulating pore sizes of the xerogels, the transfer of NGAL in xerogels can approximate that in homogeneous solution. Due to electrostatic attraction of the pore entrances, NGAL rapidly enriches on the surface and inside the xerogels. The reaction rate of NGAL and aptamer cross-linked in xerogels is also accelerated because of the nanoconfinement effect-induced increasing reactant concentration and the enhanced affinity constant KD between reactants, which can be promoted by ∼667-fold than that in bulk solution, thus achieving ultra-rapid detection (ca. 5 min) of human urine. The platform could realize one-step detection without sample pretreatments due to the antiligand exchange effect on the surface of N-doped carbon quantum dots (N-CQDs) in xerogels, in which ligand exchange between -COOH and underlying interfering ions in urine will be inhibited due to higher adsorption energy of -COOH on the N-CQD surface relative to the interfering ions. Based on the ML-extended program, the real-time analysis of the urine fluorescence spectra can be completed within 2 s. Interestingly, by changing DNA, aptamer sequences, or xerogel fluorescence intensities, the detection platform can be customized for targeted diseases.

Limitations on knowledge of autoimmune encephalitis and barriers to its treatment among neurologists: a survey from western China.

BACKGROUND: Autoimmune encephalitis (AE) is a group of severe antibody-mediated brain diseases. The understanding of clinical management of AE has developed rapidly. However, the knowledge level of AE and barriers to effective treatment among neurologists remains unstudied. METHODS: We conducted a questionnaire survey among neurologist in western China on knowledge of AE, treatment practices, and perspectives on barriers to treatment. RESULTS: A total of 1113 neurologists were invited and 690 neurologists from 103 hospitals completed the questionnaire with a response rate of 61.9%. Respondents correctly answered 68.3% of medical questions about AE. Some respondents (12.4%) never assayed for diagnostic antibodies if patients had suspected AE. Half (52.3%) never prescribed immunosuppressants for AE patients, while another 7.6% did not know whether they should do so. Neurologists who never prescribed immunosuppressants were more likely to have less education, a less senior job title, and to practice in a smaller setting. Neurologists who did not know whether to prescribe immunosuppressants were associated with less AE knowledge. The most frequent barrier to treatment, according to respondents, was financial cost. Other barriers to treatment included patient refusal, insufficient AE knowledge, lack of access to AE guidelines, drugs or diagnostic test, etc. CONCLUSION: Neurologists in western China lack AE knowledge. Medical education around AE is urgent needed and should be more targeted to individuals with less educated level or working in non-academic hospitals. Policies should be developed to increase the availability of AE related antibody testing or drugs and reduce the economic burden of disease.

Text Dialogue Analysis for Primary Screening of Mild Cognitive Impairment: Development and Validation Study.

BACKGROUND: Artificial intelligence models tailored to diagnose cognitive impairment have shown excellent results. However, it is unclear whether large linguistic models can rival specialized models by text alone. OBJECTIVE: In this study, we explored the performance of ChatGPT for primary screening of mild cognitive impairment (MCI) and standardized the design steps and components of the prompts. METHODS: We gathered a total of 174 participants from the DementiaBank screening and classified 70% of them into the training set and 30% of them into the test set. Only text dialogues were kept. Sentences were cleaned using a macro code, followed by a manual check. The prompt consisted of 5 main parts, including character setting, scoring system setting, indicator setting, output setting, and explanatory information setting. Three dimensions of variables from published studies were included: vocabulary (ie, word frequency and word ratio, phrase frequency and phrase ratio, and lexical complexity), syntax and grammar (ie, syntactic complexity and grammatical components), and semantics (ie, semantic density and semantic coherence). We used R 4.3.0. for the analysis of variables and diagnostic indicators. RESULTS: Three additional indicators related to the severity of MCI were incorporated into the final prompt for the model. These indicators were effective in discriminating between MCI and cognitively normal participants: tip-of-the-tongue phenomenon (P<.001), difficulty with complex ideas (P<.001), and memory issues (P<.001). The final GPT-4 model achieved a sensitivity of 0.8636, a specificity of 0.9487, and an area under the curve of 0.9062 on the training set; on the test set, the sensitivity, specificity, and area under the curve reached 0.7727, 0.8333, and 0.8030, respectively. CONCLUSIONS: ChatGPT was effective in the primary screening of participants with possible MCI. Improved standardization of prompts by clinicians would also improve the performance of the model. It is important to note that ChatGPT is not a substitute for a clinician making a diagnosis.

Salt-induced phosphoproteomic changes in the subfornical organ in rats with chronic kidney disease.

OBJECTIVES: Subfornical organ (SFO) is vital in chronic kidney disease (CKD) progression caused by high salt levels. The current study investigated the effects of high salt on phosphoproteomic changes in SFO in CKD rats. METHODS: 5/6 nephrectomized rats were fed a normal-salt diet (0.4%) (NC group) or a high-salt diet (4%) (HC group) for three weeks, while sham-operated rats were fed a normal-salt diet (0.4%) (NS group). For phosphoproteomic analysis of SFO in different groups, TiO2 enrichment, isobaric tags for relative and absolute quantification (iTRAQ) labeling, and liquid chromatography-tandem mass spectrometry (LC-MS/MS) were used. RESULTS: There were 6808 distinct phosphopeptides found, which corresponded to 2661 phosphoproteins. NC group had 168 upregulated and 250 downregulated phosphopeptides compared to NS group. Comparison to NC group, HC group had 154 upregulated and 124 downregulated phosphopeptides. Growth associated protein 43 (GAP43) and heat shock protein 27 (Hsp27) were significantly upregulated phosphoproteins and may protect against high-salt damage. Differential phosphoproteins with tight functional connection were synapse proteins and microtubule-associated proteins, implying that high-salt diet disrupted brain's structure and function. Furthermore, differential phosphoproteins in HC/NC comparison group were annotated to participate in GABAergic synapse signaling pathway and aldosterone synthesis and secretion, which attenuated inhibitory neurotransmitter effects and increased sympathetic nerve activity (SNA). DISCUSSION: This large scale phosphoproteomic profiling of SFO sheds light on how salt aggravates CKD via the central nervous system.

Long-term seizure outcomes in patients with autoimmune encephalitis: A prospective observational registry study update.

OBJECTIVE: This study was undertaken to update and evaluate long-term seizure outcomes in patients with autoimmune encephalitis (AE) based on a large cohort study with long follow-up. METHODS: In this prospective observational registry study, we analyzed data from patients with AE mediated by common types of neuronal surface antibodies (anti-N-methyl-d-aspartate receptor [NMDAR], anti-leucine-rich glioma-inactivated 1 [LGI1]/contactin-associated protein-like 2 [Caspr2], anti-γ-aminobutyric acid type B receptor [GABAB R]). All patients were recruited from the Department of Neurology at West China Hospital between October 2011 and June 2019, and data were collected prospectively on their demographic and clinical characteristics, treatment strategy, and seizure outcomes, with a median follow-up of 42 months (range = 6-93 months). Potential risk factors associated with seizure recurrence were also assessed. RESULTS: Of 320 AE patients, 75.9% had acute seizures, among whom >90% of patients had their last seizure within 12 months of disease onset. During our follow-up, 21 (9.3%) patients experienced seizure recurrence. Patients with anti-GABAB R encephalitis had a higher cumulative incidence of seizure recurrence than those with anti-NMDAR (log-rank p = .03) or anti-LGI1/Caspr2 encephalitis (log-rank p = .04). Among patients with anti-NMDAR encephalitis, women had a significantly higher cumulative incidence of seizure recurrence than men (log-rank p = .01). Interictal epileptiform discharges (IEDs) or seizures captured on continuous electroencephalogram (EEG) in the acute phase were identified as potential risk factors for seizure recurrence (p = .04, p = .007). Among 163 patients with ≥24 months of follow-up, five (3.1%) showed persistent seizures and required ongoing antiseizure medications despite aggressive immunotherapy. SIGNIFICANCE: Seizure recurrence occurred in a small number of patients and chronic epilepsy occurred in 3.1% of patients during prolonged follow-up. Across all types of AE, risk factors for seizure recurrence were IEDs or seizures captured on EEG in the acute phase; for anti-NMDAR encephalitis, female sex was also a risk factor.

Efficacy and tolerability of intravenous immunoglobulin versus intravenous methylprednisolone treatment in anti-N-methyl-d-aspartate receptor encephalitis.

BACKGROUND AND PURPOSE: The aim was to compare the effectiveness and safety of intravenous immunoglobulin (IVIg) or intravenous methylprednisolone (IVMP) versus IVIg plus IVMP (IPI) as initial therapy in anti-N-methyl-d-aspartate receptor (NMDAR) encephalitis. METHODS: This was a multicenter study of prospectively identified NMDAR encephalitis individuals who presented from October 2011 to August 2020 to the study hospitals of western China, with a median follow-up of 3.9 years. Prespecified candidate variables were the prescriptions of IVIg, IVMP or IPI. Propensity score matching was also performed to control potential confounders. RESULTS: A total of 347 NMDAR encephalitis patients were finally analyzed in this study. After TriMatch for NMDAR encephalitis, 37 triplets were generated. Compared to IVIg or IVMP, the administration of IPI exhibited a significant benefit of a higher response rate (86.5% vs. 55.6% vs. 68.7%, pcorr < 0.01), improved modified Rankin Scale score at 3, 6 and 12 months (pcorr < 0.05), and reduced further recurrence rate (10 of 37 [27.0%] vs. 9 of 37 [24.3%] vs. 2 of 37 [5.4%]; p log rank = 0.01). There was no association between treatment superiority and patient sex or the presence of tumors (p ≥ 0.05). Patients treated with IVMP had a significantly higher number of adverse events, but 99% of adverse events were mild to moderate and did not lead to a change in treatment. CONCLUSION: In patients with NMDAR encephalitis, adequate response, favorable outcome and less recurrence were each more likely to occur in individuals treated with a combined immunotherapy than in monotherapy individuals.

PTEN protects kidney against acute kidney injury by alleviating apoptosis and promoting autophagy via regulating HIF1-α and mTOR through PI3K/Akt pathway.

Phosphatase and tensin homolog (PTEN) deleted on human chromosome 10 is a tumor suppressor with bispecific phosphatase activity, which is often involved in the study of energy metabolism and tumorigenesis. PTEN is recently reported to participate in the process of acute injury. However, the mechanism of PTEN in Ischemia-Reperfusion Injury (IRI) has not yet been clearly elucidated. In this study, mice with bilateral renal artery ischemia-reperfusion and HK-2 cells with hypoxia/reoxygenation (H/R) were used as acute kidney injury models. We demonstrated that PTEN was downregulated in IRI-induced kidney as well as in H/R-induced HK-2 cells. By silencing and overexpressing PTEN with si-PTEN RNA and PHBLV-CMV-PTEN-flag lentivirus before H/R, we found that PTEN protected HK-2 cells against H/R-induced injury reflected by the change in cell activity and the release of LDH. Furthermore, we inhibited HIF1-α with PX-478 and inactivated mTOR with Rapamycin before the silence of PTEN in H/R model. Our data indicated that the renoprotective effect of PTEN worked via PI3K/Akt/mTOR pathway and PI3K/Akt/HIF1-α pathway, hence alleviating apoptosis and improving autophagy respectively. Our findings provide valuable insights into the molecular mechanism underlying renoprotection of PTEN on autophagy and apoptosis induced by renal IRI, which offers a novel therapeutic target for the treatment of AKI.

Prenatal exposure to di (2-ethylhexyl) phthalate causes autism-like behavior through inducing Nischarin expression in the mouse offspring.

Epidemiologic evidence has suggested a relationship between di (2-ethylhexyl) phthalate (DEHP) prenatal exposure and autism spectrum disorders (ASD), but the underlying mechanisms are still at large unknown. In this study, pregnant mice were intragastrically administered with DEHP once a day from GD 3 to GD 17 and the neurobehavioral changes of offspring were evaluated. In addition to the repetitive stereotyped behaviors, DEHP at the concentration of 50 mg/kg/day and above significantly impaired the sociability of the offspring (P < 0.05) and decreased the density of dendritic spines of pyramidal neurons in the prefrontal cortex (P < 0.05). At the same time, the expression of Nischarin protein in prefrontal lobe increased (P < 0.05). Similarly, after 12-h incubation of DEHP at the concentration of 100 nM, the total spine density, especially the mushroom and stubby spine populations, significantly decreased in the primary cultured prefrontal cortical neurons (P < 0.05). However, the inhibitory effect of DEHP were reversed by knockdown of Nischarin expression. Collectively, these results suggest that prenatal DEHP exposure induces Nischarin expression, causes dendritic spine loss, and finally leads to autism-like behavior in mouse offspring.

A Land of Controversy: Fibroblast Growth Factor-23 and Uremic Cardiac Hypertrophy.

Cardiac hypertrophy is a common feature in patients with CKD. Recent studies revealed that two phosphate regulators, fibroblast growth factor-23 and α-Klotho, are highly involved in the pathophysiologic process of CKD-induced cardiac hypertrophy. With decreasing renal function, elevated fibroblast growth factor-23 and decreased α-Klotho may contribute to cardiac hypertrophy by targeting the heart directly or by inducing systemic changes, such as vascular injury, hemodynamic disorders, and inflammation. However, several studies have demonstrated that disturbances in the fibroblast growth factor-23/α-Klotho axis do not lead to cardiac hypertrophy. In this review, we describe the cardiac effects of the fibroblast growth factor-23/α-Klotho axis and summarize recent progress in this field. In addition, we present not only the main controversies in this field but also provide possible directions to resolve these disputes.

The tst gene associated Staphylococcus aureus pathogenicity island facilitates its pathogenesis by promoting the secretion of inflammatory cytokines and inducing immune suppression.

Staphylococcus aureus (S. aureus) is an important pathogen causing various limited or systemic infections. Methicillin resistant S. aureus (MRSA) in particular presents a major clinical and public health problem. Toxic shock syndrome toxin-1 (TSST-1) encoded by the gene tst is an important virulence factor of tst positive S. aureus, leading to multi-organ malfunction. However, the mechanism of TSST-1 in pathogenesis is only partly clear. In this study, we investigated the prevalence of the tst gene in clinical isolates of S. aureus. Then, animal experiments were performed to further evaluate the influence of the presence of the tst gene associated Staphylococcus aureus Pathogenicity Island (SaPI) on body weight, serum cytokine concentrations and the bacterial load in different organs. In addition, macrophages were used to analyze the secretion of cytokines in vitro and bacterial survival in the cytoplasm. Finally, pathological analysis was carried out to evaluate organ tissue impairment. The results demonstrated that the prevalence of tst gene was approximately 17.8% of the bacterial strains examined. BALB/c mice infected with tst gene associated SaPI positive isolates exhibited a severe loss of body weight and a high bacterial load in the liver, heart, kidney and spleen. Pathological analysis demonstrated that tissue impairment was more severe after infection with tst gene associated SaPI positive isolates. Moreover, the secretion of IL-6, IL-2 and IL17A by macrophages infected with tst gene associated SaPI positive isolates clearly increased. Notably, IL-6 secretion in BALB/c mice infected with tst gene associated SaPI positive isolates was higher than that in BALB/c mice infected with negative ones. Together, these results indicated that the tst gene associated SaPI may play a critical role in the pathological process of infection via a direct and persistent toxic function, and by promoting the secretion of inflammatory cytokines that indirectly induce immune suppression.

The neuroprotective effect of apigenin against OGD/R injury in rat hippocampal neurons.

To investigate the effects of apigenin on the injury caused by oxygen and glucose deprivation in neurons and the underlying mechanisms, primary cultured rat hippocampal neurons were incubated with apigenin for 90 min before a 2-h oxygen and glucose deprivation followed by a 24-h reperfusion (OGD/R). Subsequently, cell viability, lactate dehydrogenase (LDH) leakage rate, apoptotic rate of neurons and activity of the sodium pump were assessed. In addition, activity of the sodium pump was also examined in the hippocampus of SD rats injected intraperitoneally with apigenin 90 min before a 10-min global cerebral ischemia/24-h reperfusion. The results showed that cell viability and activity of the sodium pump markedly decreased but LDH leakage rate and apoptotic rate significantly increased in OGD/R-treated neurons. However, pretreatment with apigenin (20-50µmol/L) reversed the changes dose-dependently. Compared to sham controls, activity of the sodium pump was significantly suppressed in global ischemia/reperfusion rats; application of apigenin (200mg/kg) restored the activity of the sodium pump. Furthermore, the neuroprotective effect of apigenin was blocked partly by the sodium pump inhibitor ouabain. Our findings provide the evidence that apigenin has a neuroprotective effect against OGD/R injury and the protective effect may be associated with its ability to improve sodium pump activity.

Advanced oxidation protein products promote NADPH oxidase-dependent ß-cell destruction and dysfunction through the Bcl-2/Bax apoptotic pathway.

The accumulation of plasma advanced oxidation protein products (AOPPs) has been linked with diverse disorders, including diabetes, chronic kidney disease, obesity, and metabolic syndrome. The aim of the present study was to evaluate the pathophysiological relevance of AOPPs in ß-cell destruction and dysfunction. Exposure of cultured rat ß-cells (INS-1) to AOPPs induced an increase in Bax expression, caspase-3 activity, and apoptosis as well as a decrease in Bcl-2 expression in a dose- and time-dependent manner. AOPP challenge rapidly increased the production of intracellular superoxide by activation of NADPH oxidases, demonstrated by p47phox translocation and interaction with p22phox and gp91phox, and this in turn led to apoptosis. AOPPs treatment resulted in ß-cell apoptosis, AOPPs accumulation, and decreased insulin content in pancreas and plasma in unilateral nephrectomized rats. Chronic inhibition of NADPH oxidase by apocynin prevented ß-cell apoptosis and ameliorated insulin deficiency in AOPP-challenged rats. This study demonstrates for the first time that accumulation of AOPPs promotes NADPH oxidase-dependent ß-cell destruction and dysfunction by the Bcl-2/Bax-caspase apoptotic pathway. This finding may provide a mechanistic explanation for ß-cell destruction and dysfunction in patients with diverse disorders.

Complete Sequences of mcr-1-Harboring Plasmids from Extended-Spectrum-ß-Lactamase- and Carbapenemase-Producing Enterobacteriaceae.

Here we completely sequenced four mcr-1-haboring plasmids, isolated from two extended-spectrum-ß-lactamase (ESBL)-producing Escherichia coli and two carbapenemase-producing Klebsiella pneumoniae clinical isolates. The mcr-1-harboring plasmids from an E. coli sequence type 2448 (ST2448) isolate and two K. pneumoniae ST25 isolates were identical (all pMCR1-IncX4), belonging to the IncX4 incompatibility group, while the plasmid from an E. coli ST2085 isolate (pMCR1-IncI2) belongs to the IncI2 group. A nearly identical 2.6-kb mcr-1-pap2 element was found to be shared by all mcr-1-carrying plasmids.

Detection of the mcr-1 Colistin Resistance Gene in Carbapenem-Resistant Enterobacteriaceae from Different Hospitals in China.

The spread of the plasmid-mediated colistin resistance gene, mcr-1, into carbapenem-resistant Enterobacteriaceae (CRE) clinical isolates poses a significant threat to global health. Here we report the identification of three mcr-1-harboring carbapenem-resistant Escherichia coli strains, collected from three patients in two provinces in China. Our results show that mcr-1-harboring CRE strains have started to spread in different hospitals in China. In addition, this report presents the first description of chromosomal integration of mcr-1 into a carbapenem-resistant E. coli strain.

RpoE is a Putative Antibiotic Resistance Regulator of Salmonella enteric Serovar Typhi.

Bacterial antimicrobial resistance has been associated with the up regulation of genes encoding efflux pumps and the down regulation of genes encoding outer membrane proteins (OMPs). Gene expression in bacteria is primarily initiated by sigma factors (σ factors) such as RpoE, which plays an important role in responding to many environmental stresses. Here, we report the first observation that RpoE serves as an antibiotic resistance regulator in Salmonella enteric serovar Typhi (S. Typhi). In this study, we found that the rpoE mutant (ΔrpoE) of S. Typhi GIFU10007 has elevated resistance to several antimicrobial agents, including ß-lactams, quinolones, and aminoglycosides. Genomic DNA microarray analysis was used to investigate the differential gene expression profiles between a wild type and rpoE mutant in response to ampicillin. The results showed that a total of 57 genes displayed differential expression (two-fold increase or decrease) in ΔrpoE versus the wild-type strain. The expressions of two outer membrane protein genes, ompF and ompC, were significantly down-regulated in ΔrpoE (six and seven-fold lower in comparison to wild-type strain) and RamA, a member of the efflux pump AraC/XylS family, was up-regulated about four-fold in the ΔrpoE. Our results suggest RpoE is a potential antimicrobial regulator in S. Typhi, controlling both the down regulation of the OMP genes and up-regulating the efflux system.