Curcumin reduces myocardial ischemia-reperfusion injury, by increasing endogenous H2S levels and further modulating m6A.

BACKGROUND: Our previous research shows that Curcumin (CUR) attenuates myocardial ischemia-reperfusion injury (MIRI) by reducing intracellular total RNA m6A levels. However, the mechanism remains unknown. METHODS: For ischemia-reperfusion (IR), H9c2 cells were cultured for 6 h in serum-free low-glycemic (1 g/L) medium and a gas environment without oxygen, and then cultured for 6 h in high-glycemic (4.5 g/L) medium supplemented with 10% FBS and a 21% oxygen environment. The effects of different concentrations of CUR (5, 10, and 20 µM) treatments on signaling molecules in conventionally cultured and IR-treated H9c2 cells were examined. RESULTS: CUR treatment significantly up-regulated the H2S levels, and the mRNA and protein expression of cystathionine γ-lyase (CSE), and down-regulated the mRNAs and proteins levels of thiosulfate sulfurtransferase (TST) and ethylmalonic encephalopathy 1 (ETHE1) in H9c2 cells conventionally cultured and subjected to IR. Exogenous H2S supply (NaHS and GYY4137) significantly reduced intracellular total RNA m6A levels, and the expression of RNA m6A "writers" METTL3 and METTL14, and increased the expression of RNA m6A "eraser" FTO in H9c2 cells conventionally cultured and subjected to IR. CSE knockdown counteracted the inhibitory effect of CUR treatment on ROS production, promotion on cell viability, and inhibition on apoptosis of H9c2 cells subjected to IR. CONCLUSION: CUR attenuates MIRI by regulating the expression of H2S level-regulating enzymes and increasing the endogenous H2S levels. Increased H2S levels could regulate the m6A-related proteins expression and intracellular total RNA m6A levels.

Successful pregnancy in the blind hemicavity of Robert's uterus: a rare case report and brief literature review.

BACKGROUND: Robert's uterus is a rare congenital anomaly, characterized as an asymmetric septate uterus that has a blind hemicavity with unilateral menstrual fluid retention and a unicornuate hemicavity connecting to the cervix unimpededly. Patients with Robert's uterus generally present with menstrual disorders and dysmenorrhea, and some may have reproductive problems as well, including infertility, recurrent miscarriage, preterm labor and obstetric complications. In this case, we describe a successful pregnancy implanted on the obstructed hemicavity and delivered a liveborn girl. Meanwhile, we highlight diagnostic and therapeutic difficulties in patients with atypical symptoms of Robert's uterus. CASE PRESENTATION: A 30-year-old Chinese primigravida sought for emergency treatment at 26 weeks and 2 days of gestation because of preterm premature rupture of membranes (PPROM). At the age of 19, the patient was misdiagnosed with hyperprolactinemia and pituitary microadenoma for showing symptom of hypomenorrhea and was suspected to have a uterine septum in the first trimester. She was diagnosed with Robert's uterus at 22 weeks of gestation by repetitious prenatal transvaginal ultrasonography, which was subsequently confirmed by magnetic resonance imaging. At 26 weeks and 3 days of gestation, the patient was suspected to have oligohydramnion, irregular uterine contraction, and umbilical cord prolapse, and she expressed a strong will of saving the baby. Emergency cesarean delivery was performed and a small hole, together with several weak spots, was found at the lower and back wall of the septum of the patient. The treatment was effective and both the mother and the infant, who had an extremely low birth weight, were discharged in good health conditions. CONCLUSIONS: Pregnancy in the blind cavity of Robert's uterus with living neonates is incredibly rare. In our case, the favorable outcome may result from the unusual hole found at the septum, which may play a role in communicating amniotic fluid between the two hemicavities so to keep the neonate alive. we highlight the importance of early diagnosis and pre-pregnancy treatment of this uterine malformation, and the timely termination of pregnancy, for improving birth quality and reducing mortality.

Bone Penetration of Cycloserine in Osteoarticular Tuberculosis Patients of China.

The cycloserine concentrations in plasma and bone that were collected during operations on 28 osteoarticular tuberculosis (TB) patients treated daily with a 500-mg cycloserine-containing regimen were determined. The median concentrations in plasma and bone were 16.29 µg/mL (interquartile range [IQR], 6.47 µg/mL) and 24.33 µg/g (IQR, 14.68 µg/g), respectively. The median bone/plasma penetration ratio was 0.76 (range, 0.33 to 1.98). Cycloserine could effectively penetrate bone and acquire concentrations comparable to those in plasma, which favors its usage in osteoarticular TB treatment.

pH/ROS dual-sensitive and chondroitin sulfate wrapped poly (ß-amino ester)-SA-PAPE copolymer nanoparticles for macrophage-targeted oral therapy for ulcerative colitis.

An oral nanoparticle (NPs) encapsulated in chitosan/alginate hydrogel (CA-Gel) with dual-sensitive in pH and reactive oxygen species (ROS) was developed to load curcumin (CUR) based on the intracellular-specific characteristics of macrophages. Chondroitin sulfate (CS) wrapped PBAE-SA-PAPE with intracellular pH/ROS dual-sensitive characteristics and CUR via a simple nanoprecipitation method to form NPs (CS-CUR-NPs), and mixed CA-Gel to acquire the final preparation (CS-CUR-NPs-Gel). CS-CUR-NPs displayed an ideal average particle size (179.19±5.61nm) and high encapsulating efficiency (94.74±1.15%). CS showed a good targeting ability on macrophages and the CA-Gel contribution in protecting NPs from being destroyed in the upper gastrointestinal tract. As expected, CS-CUR-NPs-Gel could significantly alleviate inflammation in DSS-induced UC mice via TLR4-MAPK/NF-κB pathway. This study is the first to attempt to design a novel pH/ROS dual-stimulated release strategy in helping intracellular CUR delivery and anticipated for efficient anti-UC therapy.

Influence of ambient air pollution on successful pregnancy with frozen embryo transfer: A machine learning prediction model.

Numerous air pollutants have been reported to influence the outcomes of in vitro fertilization (IVF). However, whether air pollution affects implantation in frozen embryo transfer (FET) process is under debate. We aimed to find the association between ambient air pollution and implantation potential of FET and test the value of adding air pollution data to a random forest model (RFM) predicting intrauterine pregnancy. Using a retrospective study of a 4-year single-center design，we analyzed 3698 cycles of women living in Shanghai who underwent FET between 2015 and 2018. To estimate patients' individual exposure to air pollution, we computed averages of daily concentrations of six air pollutants including PM2.5, PM10, SO2, CO, NO2, and O3 measured at 9 monitoring stations in Shanghai for the exposure period (one month before FET). Moreover, A predictive model of 15 variables was established using RFM. Air pollutants levels of patients with or without intrauterine pregnancy were compared. Our results indicated that for exposure periods before FET, NO2 were negatively associated with intrauterine pregnancy (OR: 0.906, CI: 0.816-0.989). AUROC increased from 0.712 to 0.771 as air pollutants features were added. Overall, our findings demonstrate that exposure to NO2 before transfer has an adverse effect on clinical pregnancy. The performance to predict intrauterine pregnancy will improve with the use of air pollution data in RFM.

Anti-inflammatory effect of Rhein on ulcerative colitis via inhibiting PI3K/Akt/mTOR signaling pathway and regulating gut microbiota.

This study aimed to analyze the therapeutic effect of Rhein on ulcerative colitis (UC) in mice and its possible mechanism. LPS-induced UC cell model and DSS-induced UC mouse model were used to analyze the antiinflammatory effect of Rhein on UC in vitro and in vivo, respectively. Network pharmacology analysis was conducted to identify potential signaling pathways involved in Rhein treating UC, and the results were further confirmed through western blotting assay. 16sRNA sequencing was performed to study the regulatory effect of Rhein on gut microbiota in UC mice. As indicated by the results, Rhein could significantly inhibit the production of pro-inflammatory cytokines (e.g., TNF-α, IL-6 and IL-1ß) in vivo and in vitro, and alleviate DSS-induced UC-associated symptoms in mice (e.g., colon shortening, weight loss, diarrhea and hematochezia). The PI3K/Akt/mTOR signaling pathway was predicted as the potential interacting protein of Rhein in the treatment of UC through network pharmacology analysis. It was found through western blotting assay that the Rhein treatment could significantly inhibit the PI3K/Akt/mTOR signaling pathway by decreasing the phosphorylated protein levels of PI3K, Akt, mTOR and p70S6K1. By 16sRNA gene sequencing analysis, Rhein administration could partially reverse the gut dysbacteriosis of mice induced by DSS and decrease pathogenic bacteria (e.g., Enterobacteriaceae and Turicibacter). It was positively correlated with the production of pro-inflammatory cytokines above, whereas the increase in probiotics (e.g., Unspecified-S24-7 and Rikenellaceae) was negatively correlated with the production of pro-inflammatory cytokines. In conclusion, Rhine had anti-UC efficacy, which was demonstrated by mitigating the UC symptoms and reducing intestinal inflammation by inhibiting the PI3K/Akt/mTOR signaling pathway and modulating gut microbiota.

[Mechanism of combined treatment of rhein and emodin in Rhubarb for ulcerative colitis].

This study aimed to explore the efficacy and mechanism of combined rhein and emodin in the treatment of ulcerative colitis(UC) from the aspects of network pharmacology, animal inflammation improvement and molecular mechanism. Network pharmacology predicted that combined rhein and emodin acted on 52 potential targets, mainly participating in signaling pathways such as cancer, PI3 K/AKT, microRNAs in cancer and apoptosis. PI3 K/AKT signaling pathway has been reported to be closely related to UC, and the optimal candidate pathway for combined therapy. The UC mice model was established by dextran sodium sulfate, and then the modeled mice were randomly divided into control group, model group, rhein group, emodin group, rhein+emodin group and sulfasalazine group. After administration, compared with the conditions in model group, body weight, disease activity index(DAI) score, colon length, TNF-α, IL-6, IL-1ß and myeloperoxidase(MPO) of mice in rhein+emodin group were improved(P<0.01); colonic mucosal injury was significantly reduced; the expression of p-PI3 K/PI3 K and p-AKT/AKT proteins were down-regulated(P<0.01). All the above indices were better than those in the rhein/emodin group alone. The Jin's Q-values of the effect of combined rhein and emodin on colon length, TNF-α, IL-6, IL-1ß, MPO, p-PI3 K/PI3 K and p-AKT/AKT were all greater than 1.15, which indicated that there was obvious synergistic effect between rhein and emodin. In all, rhein and emodin have synergistic effect in the treatment of UC, and the mechanism may be related to the inhibition of PI3 K/AKT signaling pathway and the down-regulation of proinflammatory factors. They are the new components in the treatment of UC, which is worthy of attention.

Lipid metabolism in asthma: Immune regulation and potential therapeutic target.

Asthma is a chronic inflammatory disease of the lungs that poses a considerable health and socioeconomic burden. Several risk factors work synergistically to affect the progression of asthma. Lipid metabolism, especially in distinct cells such as T cells, macrophages, granulocytes, and non-immune cells, plays an essential role in the pathogenesis of asthma, as lipids are potent signaling molecules that regulate a multitude of cellular response. In this review, we focused on the metabolic pathways of lipid molecules, especially fatty acids and their derivatives, and summarized their roles in various cells during the pathogenesis of asthma along with the current pharmacological agents targeting lipid metabolism.

CircNOL10 suppresses breast cancer progression by sponging miR-767-5p to regulate SOCS2/JAK/STAT signaling.

BACKGROUND: Circular RNAs (circRNAs) have caught increasing attentions and interests for their important involvement in cancer initiation and progression. This study aims to investigate the biological functions of circNOL10 and its potential molecular mechanisms in breast cancer (BC). MATERIALS AND METHODS: qRT-PCR and western blot assays were performed to measure the expression of related genes. CCK-8, colony formation, flow cytomerty and transwell assays were used to assess cell proliferation, cell cycle, migration and invasion. RNA pull-down, luciferase reporter and RIP assays were applied to address the potential regulatory mechanism of circNOL10. RESULTS: CircNOL10 was down-regulated in BC tissues and cells. Low expression of circNOL10 was associated with larger tumor size, advanced TNM stage, lymph node metastasis and unfavorable prognosis. Overexpression of circNOL10 inhibited cell proliferation, migration, invasion and EMT in vitro and slowed xenograft tumor growth in vivo. Mechanistically, circNOL10 could act as a molecular sponge for miR-767-5p, leading to the up-regulation of suppressors of cytokine signaling 2 (SOCS2) and inactivation of JAK2/STAT5 pathway. Moreover, circNOL10-mediated suppression of malignant phenotypes was attenuated by miR-767-5p. Similar to circNOL10, enforced expression of SOCS2 also resulted in the suppression of cell proliferation and metastasis. Furthermore, knockdown of SOCS2 reversed the tumor-suppressive effect induced by circNOL10. CONCLUSIONS: CircNOL10 repressed BC development via inactivation of JAK2/STAT5 signaling by regulating miR-767-5p/SOCS2 axis. Our findings offer the possibility of exploiting circNOL10 as a therapeutic and prognostic target for BC patients.

Entrapment of Macrophage-Target Nanoparticles by Yeast Microparticles for Rhein Delivery in Ulcerative Colitis Treatment.

In this study, we developed an advanced colitis-targeted nanoparticles (NPs)-into-yeast cell wall microparticles (YPs) drug delivery system for ulcerative colitis (UC) therapy. In brief, YPs entrap hyaluronic acid (HA), and polyethylenimine (PEI) modified rhein (RH)-loaded ovalbumin NPs (HA/PEI-RH NPs) to form HA/PEI-RH NYPs. YPs can make HA/PEI-RH NPs pass through gastric environment stably and be degraded by ß-glucanase to promote drug release from HA/PEI-RH NYPs in the colon. Cellular uptake evaluation confirmed that HA/PEI-RH NPs could specifically target and enhance the uptake rate via HA ligands. In biodistribution studies, HA/PEI-RH NYPs were able to efficiently accumulate in the inflammed colon in mice. In vivo experiments revealed that the HA/PEI-RH NYPs could significantly alleviate inflammation by inhibiting the TLR4/MyD88/NF-κB signaling pathway. Therefore, HA/PEI-RH NYPs have advantages of good gastric stability, ß-glucanase-sensitive release ability, macrophage-targeted ability, and anti-UC effects. These advantages indicate YPs-entrapped multifunctional NPs are a promising oral drug delivery system for UC therapy.

Mycobacterium vicinigordonae sp. nov., a slow-growing scotochromogenic species isolated from sputum.

A slow-growing, scotochromogenic mycobacterial strain (24T) was isolated from the sputum of a Chinese male human. Phylogenetic analysis using the 16S rRNA gene assigned strain 24T to the Mycobacterium gordonae complex, which includes Mycobacterium gordonae and Mycobacterium paragordonae. The phenotypic characteristics, unique mycolic acid profile and the results of phylogenetic analysis based on hsp65 and rpoB sequences strongly supported the taxonomic status of strain 24T as a representative of a species distinct from the other members of the M. gordonae complex. The genomic G+C content of strain 24T was 65.40mol%. Genomic comparisons showed that strain 24T and M. gordonae ATCC 14470T had an average nucleotide identity (ANI) value of 81.00 % and a DNA-DNA hybridization (DDH) value of 22.80 %, while the ANI and DDH values between strain 24Tand M. paragordonae 49 061T were 80.98 and 22.80 %, respectively. In terms of phylogenetic, phenotypic and chemotaxonomic features, strain 24T is distinguishable from its closest phylogenetic relatives and represents a novel species of the genus Mycobacterium, therefore the name Mycobacterium vicinigordonae sp. nov. is proposed. The type strain is 24T (=CMCC 93559T=DSM 105979T).

Highly efficient BiVO4single-crystal nanosheets with dual modification: phosphorus doping and selective Ag modification.

BiVO4, a visible-light response photocatalyst, has shown tremendous potential because of abundant raw material sources, good stability and low cost. There exist some limitations for further applicaitions due to poor capability to separate electron-hole pairs. In fact, a single-component modification strategy is barely adequate to obtain highly efficient photocatalytic performance. In this work, P substituted some of the V atoms from VO4oxoanions, namely P was doped into the V sites in the host lattice of BiVO4by a hydrothermal route. Meanwhile, Ag as an attractive and efficient electron-cocatalyst was selectively modified on the (010) facet of BiVO4nanosheets via facile photo-deposition. As a result, the obtained dually modified BiVO4sheets exhibited enhanced photocatalytic degradation property of methylene blue (MB). In detail, photocatalytic rate constant (k) was 2.285 min-1g-1, which was 2.78 times higher than pristine BiVO4nanosheets. Actually, P-doping favored the formation of O vacancies, led to more charge carriers, and facilitated photocatalytic reaction. On the other hand, metallic Ag loaded on (010) facet effectively transferred photogenerated electrons, which consequently helped electron-hole pairs separation. The present work may enlighten new thoughts for smart design and controllable synthesis of highly efficient photocatalytic materials.

MTOR suppresses autophagy-mediated production of IL25 in allergic airway inflammation.

INTRODUCTION: Airway epithelial cells are recognised as an essential controller for the initiation and perpetuation of asthmatic inflammation, yet the detailed mechanisms remain largely unknown. This study aims to investigate the roles and mechanisms of the mechanistic target of rapamycin (MTOR)-autophagy axis in airway epithelial injury in asthma. METHODS: We examined the MTOR-autophagy signalling in airway epithelium from asthmatic patients or allergic mice induced by ovalbumin or house dust mites, or in human bronchial epithelial (HBE) cells. Furthermore, mice with specific MTOR knockdown in airway epithelium and autophagy-related lc3b-/- mice were used for allergic models. RESULTS: MTOR activity was decreased, while autophagy was elevated, in airway epithelium from asthmatic patients or allergic mice, or in HBE cells treated with IL33 or IL13. These changes were associated with upstream tuberous sclerosis protein 2 signalling. Specific MTOR knockdown in mouse bronchial epithelium augmented, while LC3B deletion diminished allergen-induced airway inflammation and mucus hyperproduction. The worsened inflammation caused by MTOR deficiency was also ameliorated in lc3b-/- mice. Mechanistically, autophagy was induced later than the emergence of allergen-initiated inflammation, particularly IL33 expression. MTOR deficiency increased, while knocking out of LC3B abolished the production of IL25 and the eventual airway inflammation on allergen challenge. Blocking IL25 markedly attenuated the exacerbated airway inflammation in MTOR-deficiency mice. CONCLUSION: Collectively, these results demonstrate that allergen-initiated inflammation suppresses MTOR and induces autophagy in airway epithelial cells, which results in the production of certain proallergic cytokines such as IL25, further promoting the type 2 response and eventually perpetuating airway inflammation in asthma.

Cigarette smoke-initiated autoimmunity facilitates sensitisation to elastin-induced COPD-like pathologies in mice.

It is currently not understood whether cigarette smoke exposure facilitates sensitisation to self-antigens and whether ensuing auto-reactive T cells drive chronic obstructive pulmonary disease (COPD)-associated pathologies.To address this question, mice were exposed to cigarette smoke for 2 weeks. Following a 2-week period of rest, mice were challenged intratracheally with elastin for 3 days or 1 month. Rag1-/- , Mmp12-/- , and Il17a-/- mice and neutralising antibodies against active elastin fragments were used for mechanistic investigations. Human GVAPGVGVAPGV/HLA-A*02:01 tetramer was synthesised to assess the presence of elastin-specific T cells in patients with COPD.We observed that 2 weeks of cigarette smoke exposure induced an elastin-specific T cell response that led to neutrophilic airway inflammation and mucus hyperproduction following elastin recall challenge. Repeated elastin challenge for 1 month resulted in airway remodelling, lung function decline and airspace enlargement. Elastin-specific T cell recall responses were dose dependent and memory lasted for over 6 months. Adoptive T cell transfer and studies in T cells deficient Rag1-/- mice conclusively implicated T cells in these processes. Mechanistically, cigarette smoke exposure-induced elastin-specific T cell responses were matrix metalloproteinase (MMP)12-dependent, while the ensuing immune inflammatory processes were interleukin 17A-driven. Anti-elastin antibodies and T cells specific for elastin peptides were increased in patients with COPD.These data demonstrate that MMP12-generated elastin fragments serve as a self-antigen and drive the cigarette smoke-induced autoimmune processes in mice that result in a bronchitis-like phenotype and airspace enlargement. The study provides proof of concept of cigarette smoke-induced autoimmune processes and may serve as a novel mouse model of COPD.

Early recruited neutrophils promote asthmatic inflammation exacerbation by release of neutrophil elastase.

Neutrophils can regulate adaptive immune responses and contribute to chronic inflammation including asthma. However, the roles and mechanisms of neutrophils in initiating eosinophilic airway inflammation remain incompletely understood. Neutrophil elastase (NE) is a component of azurophilic granules and a serine protease with potent functions during inflammation. Here, we showed that neutrophils were early recruited at the onset of asthmatic inflammation by related chemokines. Furthermore, neutrophils could capture allergens and release NE to promote neutrophil aggregation at first. Then they prompt eosinophil infiltration and amplify type 2 immune responses in later phases. Also, this process can be rescued by administration of the NE inhibitor (GW311616). Our data collectively indicate that neutrophils could contribute to asthmatic inflammation by releasing NE.

MTOR Suppresses Environmental Particle-Induced Inflammatory Response in Macrophages.

Increasing toxicological and epidemiological studies have demonstrated that ambient particulate matter (PM) could cause adverse health effects including inflammation in the lung. Alveolar macrophages represent a major type of innate immune responses to foreign substances. However, the detailed mechanisms of inflammatory responses induced by PM exposure in macrophages are still unclear. We observed that coarse PM treatment rapidly activated mechanistic target of rapamycin (MTOR) in mouse alveolar macrophages in vivo, and in cultured mouse bone marrow-derived macrophages, mouse peritoneal macrophages, and RAW264.7 cells. Pharmacological inhibition or genetic knockdown of MTOR in bone marrow-derived macrophages leads to an amplified cytokine production upon PM exposure, and mice with specific knockdown of MTOR or ras homolog enriched in brain in myeloid cells exhibit significantly aggregated airway inflammation. Mechanistically, PM activated MTOR through modulation of ERK, AKT serine/threonine kinase 1, and tuberous sclerosis complex signals, whereas MTOR deficiency further enhanced the PM-induced necroptosis and activation of subsequent NF κ light-chain-enhancer of activated B cells (NFKB) signaling. Inhibition of necroptosis or NFKB pathways significantly ameliorated PM-induced inflammatory response in MTOR-deficient macrophages. The present study thus demonstrates that MTOR serves as an early adaptive signal that suppresses the PM-induced necroptosis, NFKB activation, and inflammatory response in lung macrophages, and suggests that activation of MTOR or inhibition of necroptosis in macrophages may represent novel therapeutic strategies for PM-related airway disorders.

NAMPT regulates PKM2 nuclear location through 14-3-3ζ: Conferring resistance to tamoxifen in breast cancer.

The resistance against tamoxifen therapy has become one of the major obstacles in the clinical treatment of breast cancer. Nicotinamide phosphoribosyltransferase (NAMPT) is an essential enzyme catalyzing nicotinamide adenine dinucleotide biosynthesis and is important for tumor metabolism. The study here sought to explore the effect of NAMPT on breast cancer survival with tamoxifen conditioning. We found that NAMPT was highly expressed in breast cancer cells compared with normal mammary epithelial cells. Inhibition of NAMPT by FK866 inhibited cell viability and aggravated apoptosis in cancer cells treated with 4-hydroxytamoxifen. NAMPT overexpression upregulated 14-3-3ζ expression. Knockdown of 14-3-3ζ reduced cell survival and promoted apoptosis. Activation of Akt signaling, rather than ERK1/2 pathway, is responsible for 14-3-3ζ regulation by NAMPT overexpression. Furthermore, NAMPT overexpression led to PKM2 accumulation in the cell nucleus and could be dampened by 14-3-3ζ inhibition. In addition, NAMPT overexpression promoted xenografted tumor growth and apoptosis in nude mice, while 14-3-3ζ inhibition attenuated its effect. Collectively, our data demonstrate that NAMPT contributes to tamoxifen resistance through regulation of 14-3-3ζ expression and PKM2 translocation.

In Vitro Activities of Bedaquiline and Delamanid against Nontuberculous Mycobacteria Isolated in Beijing, China.

Due to the natural resistance of nontuberculous mycobacteria (NTM) against multiple antibiotics, treatment of infections caused by them is often long-course and less successful. The main objective of our study was the evaluation of in vitro susceptibility of 209 isolates consisting of different NTM species against bedaquiline and delamanid. Furthermore, reference strains of 33 rapidly growing mycobacterium (RGM) species and 19 slowly growing mycobacterium (SGM) species were also tested. Bedaquiline exhibited strong in vitro activity against both reference strains and clinical isolates of different SGM species, as the majority of the strains demonstrated MICs far below 1 µg/ml. Bedaquiline (Bdq) also exhibited potent activity against the recruited RGM species. A total of 29 out of 33 reference RGM strains had MICs lower than 1 µg/ml. According to the MIC distributions, the tentative epidemiological cutoff (ECOFF) values, and the pharmacokinetic data, a uniform breakpoint of 2 µg/ml was temporarily proposed for NTM's Bdq susceptibility testing. Although delamanid (Dlm) was not active against most of the tested reference strains and clinical isolates of RGM species, it exhibited highly variable antimicrobial activities against the 19 tested SGM species. Eleven species had MICs lower than 0.25 µg/ml, and 7 species had MICs greater than 32 µg/ml. Large numbers of M. kansasii (39/45) and M. gordonae (6/10) clinical isolates had MICs of ≤0.125 µg/ml. This study demonstrated that bedaquiline had potent activity against different NTM species in vitro, and delamanid had moderate activity against certain species of SGM. The data provided important insights on the possible clinical application of Bdq and Dlm to treat NTM infections.

GeneXpert of stool versus gastric lavage fluid for the diagnosis of pulmonary tuberculosis in severely ill adults.

PURPOSE: Stool is an alternative specimen matrix for tuberculosis (TB) tests, because Mycobacterium tuberculosis (MTB) can be swallowed and detected in the samples from digestive tract. We aimed to assess the performance of GeneXpert on stool and gastric lavage fluid (GALF) in diagnosing TB among patients with severe pulmonary TB. METHODS: We enrolled adults with suspected pulmonary TB who were unable to produce sputum at visit between January 2016 and June 2018. Bacteriological samples consisted of one transtracheal aspirate sputum specimen, one stool specimen and/or one gastric lavage fluid specimen. Bacterial culture of transtracheal aspirate sputum provided the gold standard. RESULTS: Of 65 individuals recruited for analysis, MGIT culture identified the presence of MTB in 32 samples. Overall, 29 of 32 stool samples from culture-positive cases were detected by the GeneXpert test, demonstrating a sensitivity of 90.6%. For GALF, 13 patients were detected as infected with MTB by GeneXpert, yielding a sensitivity of 56.5%. The statistical analysis revealed that GeneXpert showed significantly better sensitivity in detecting MTB from stool samples than GALF samples (P = 0.003). Among individuals with GeneXpert-positive stool, the percentage of individuals with comorbid diabetes was significantly higher than among individuals with GeneXpert-negative stool (19.4% vs. 2.9%, P = 0.034). CONCLUSIONS: In conclusion, our data reveal that GeneXpert provides a higher detection rate on stool compared to GALF, indicating stool should be considered as an alternative for adult TB patients unable to produce sputum. Individuals with diabetes are more likely to have positive GeneXpert stool than nondiabetic individuals.

Change in prevalence and molecular characteristics of isoniazid-resistant tuberculosis over a 10-year period in China.

BACKGROUND: Isoniazid (INH) represents the cornerstone for the treatment of cases infected with Mycobacterium tuberculosis (MTB) strains. Several molecular mechanisms have been shown to be the major causes for INH resistance, while the dynamic change of mutations conferring INH resistance among MTB strains during the past decade is still unknown in China. METHODS: In this study, we carried out a comparative analysis of the INH minimal inhibitory concentration (MIC) distribution, and investigate the dynamic change of molecular characteristics among INH-resistant MTB strains between 2005 and 2015. RESULTS: The proportion of INH resistance (39.0%, 105/269) in 2015 was significantly higher than in 2005 (30.0%, 82/273; P = 0.03). Among 269 isolates collected in 2015, 76 (28.3%, 76/269) exhibited high-level INH-resistance (MIC≥32 mg/L), which was significantly higher than that in 2005 (20.5%, 56/273, P = 0.04). In addition, a significantly higher percentage of INH-resistant isolates carried inhA promoter mutations in 2015 (26.7%) versus that in 2005 (14.6%, P = 0.04), while no significant difference was observed in the rates of isolates containing katG mutations between 2005 (76.8%) and 2015 (70.5%, P = 0.33). Notably, the proportion of MTB isolates with inhA mutations (26.7%, 28/105) for patients who had previous exposure to protionamide (PTH) was higher than that for patients who had no previous exposure to PTH (21.4%, 6/28). CONCLUSIONS: In conclusion, our results demonstrated that the proportion of INH-resistant MTB isolates significantly increased during the last decade, which was mainly attributed to an increase of high-level INH-resistant MTB. In addition, prior exposure to PTH may be associated with the increased frequency of INH-resistant tuberculosis strains with inhA mutations in China.