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Berberine (BBR) is a traditional Chinese herb with broad antimicrobial activity. Gut microbiota plays an important role in the metabolism of bile acids and cholesterol. Our study investigated the effects of BBR on alleviating cholesterol and bile acid metabolism disorders induced by high cholesterol diet in mice. Adult male C57BL/6J mice fed with high cholesterol diet (HC) containing 1.25 % cholesterol (HC group) or fed with chow diet containing 0.02 % cholesterol (Chow group) served as controls. BBR50 and BBR100 group mice were fed with HC, and oral BBR daily at doses of 50 or 100 mg/kg respectively for 8 weeks. The results showed that BBR could reshape the homeostasis and composition of gut microbiota. The abundance of Clostridium genera was significantly inhibited by BBR, which resulted in a significant reduction of secondary bile acids within the enterohepatic circulation and a significant lower hydrophobic index of bile acids. The absorption of cholesterol in intestine, the deposition of cholesterol in liver and the excretion of cholesterol in biliary tract were significantly inhibited by BBR, which promoted the unsaturation of cholesterol in bile. These findings suggest the potential utility of BBR as a functional food to alleviate the negative effects of high cholesterol diet.
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Berberina , Ácidos e Sais Biliares , Colesterol na Dieta , Colesterol , Microbioma Gastrointestinal , Camundongos Endogâmicos C57BL , Animais , Berberina/farmacologia , Ácidos e Sais Biliares/metabolismo , Masculino , Colesterol/metabolismo , Camundongos , Microbioma Gastrointestinal/efeitos dos fármacos , Colesterol na Dieta/efeitos adversos , Colesterol na Dieta/metabolismo , Dieta Hiperlipídica/efeitos adversos , Fígado/metabolismo , Fígado/efeitos dos fármacosRESUMO
AIM: To investigate the differences in gut microbiota composition among nonpregnant women of reproductive age, healthy pregnant women, and gestational diabetes (GD) patients. METHODS: A total of 45 outpatients were enrolled and divided into three groups: nonpregnant women of reproductive age (control group, n = 23), healthy pregnant women (normal group, n = 10), and GD patients (GD group, n = 12). Faecal samples were collected and sequenced using 16S rRNA gene sequencing to analyse the microbial composition. RESULTS: (1) Pregnant patients exhibited an increase in the abundance of Streptococcus (Pnormal = 0.01286, PGD = 0.002965) and Blautia (Pnormal = 0.0003924, PGD = 0.000246) but a decrease in the abundance of Roseburia (Pnormal = 0.0361, PGD = 0.007075), Phascolarctobacterium (Pnormal = 0.0003906, PGD = 0.02499) and Lachnoclostridium (Pnormal = 0.0003906, PGD = 0.03866). (2) Compared with healthy pregnant women, GD patients had an excessive increase in Streptococcus abundance and decrease in Roseburia abundance. The increase in Blautia abundance and the decrease in Phascolarctobacterium and Lachnoclostridium abundance in GD patients were less than those in healthy pregnant women. (3) The abundance of Faecalibacterium prausnitzii decreased significantly in GD patients (PGD = 0.02985) but not in healthy pregnant patients (Pnormal = 0.1643). CONCLUSIONS: Abnormal increases and decreases in the abundances of gut microbiota components, especially Faecalibacterium prausnitzii, were observed in GD patients. TRIAL REGISTRATION: The cross-sectional research was conducted in accordance with the Declaration of Helsinki, and approved by Sir Run Run Shaw Hospital Clinical Trials and Biomedical Ethics Committee. The study has been registered in the Chinese Clinical Trial Registry (ChiCTR1900026164, 24/09/2019, http://www.chictr.org.cn/showproj.aspx?proj=43,455 ).
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Diabetes Gestacional , Microbioma Gastrointestinal , Feminino , Humanos , Gravidez , Estudos Transversais , Diabetes Gestacional/microbiologia , Fezes/microbiologia , RNA Ribossômico 16S/genéticaRESUMO
OBJECTIVES: To investigate the molecular characteristics and transferability of plasmid-borne linezolid resistance genes optrA, cfr, poxtA2 and cfr(D) genes in one linezolid-resistant Enterococcus faecalis DM86 from retail meat. METHODS: E. faecalis DM86 was screened for the presence of known linezolid resistance genes via PCR analysis. Conjugation experiments were used to evaluate the transferability of the resistance genes. The complete genome of E. faecalis DM86 was obtained using both the Illumina and Nanopore platforms. RESULTS: Analysis of the complete sequence showed that E. faecalis DM86 belonged to sequence type 116 (ST116). Four linezolid resistance genes were identified on three plasmids, designated as pDM86-2-cfr, pDM86-3-optrA and pDM86-4-poxtA [cfr(D) co-located]. IS1216 mobile elements were found to flank the cfr and optrA locus on these two plasmids. pDM86-3-optrA encoded the RDK-type OptrA protein and a common genetic array of 'IS1216-fexA-optrA-erm(A)-IS1216' was identified on this plasmid. The cfr(D) gene was closely associated with the poxtA2 gene on pDM86-4-poxtA, and similar plasmids and structures were reported recently in the E. faecalis of animal origin. The intra- and inter-species horizontal transferability of this plasmid to E. faecalis JH2-2, Enterococcus faecium BM4105RF and Staphylococcus aureus RN4220 was also proved, with a frequency of 2.8â×â10-3, 1.7â×â10-3 and 3.4â×â10-5, respectively. CONCLUSIONS: This was the first report of the co-existence of up to four plasmid-borne linezolid resistance genes in one E. faecalis. Thus, efficient actions should be exerted to circumvent the microbiota contamination of food and the further spread of these antimicrobial resistance reservoirs.
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Enterococcus faecium , Infecções por Bactérias Gram-Positivas , Animais , Linezolida/farmacologia , Enterococcus faecalis , Antibacterianos/farmacologia , Farmacorresistência Bacteriana/genética , Plasmídeos/genética , Carne , Testes de Sensibilidade MicrobianaRESUMO
BACKGROUND: Cholesterol gallstone disease is a common disease. Reducing cholesterol burden is important to prevent/treat gallstone. In this study, we investigated the application of diosgenin (DG) to prevent the formation of gallstone in mice. METHODS: Adult male C57BL/6J mice were fed with the lithogenic diet (LD) only or LD supplemented with DG or ezetimibe for 8 weeks. Incidences of gallstone formation were documented. Intestine and liver tissues were collected to measure the lipid contents and expression of genes in cholesterol metabolism. Caco2 cells were treated with DG to monitor the regulation on cholesterol absorption and the transcriptional regulation of Npc1l1 gene. Changes of gut microbiota by DG was analyzed. Intraperitoneal injection of LPS on mice was performed to verify its effects on STAT3 activation and Npc1l1 expression in the small intestine. RESULTS: LD led to 100% formation of gallstones in mice. In comparison, dietary DG or ezetimibe supplementary completely prevents gallstones formation. DG inhibited intestinal cholesterol absorption in mice as well as in Caco2 cells by down-regulation of Npc1l1 expression. DG could directly inhibit phosphorylation of STAT3 and its transcriptional regulation of Npc1l1 expression. Furthermore, DG could modulate gut microbiota profiles and LPS mediated STAT3 activation and Npc1l1 expression. CONCLUSION: Our results demonstrated that dietary DG could inhibit intestinal cholesterol absorption through decreasing NPC1L1 expression to prevent cholesterol gallstone formation.
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Diosgenina , Cálculos Biliares , Humanos , Camundongos , Masculino , Animais , Cálculos Biliares/prevenção & controle , Cálculos Biliares/metabolismo , Proteínas de Membrana Transportadoras/genética , Proteínas de Membrana Transportadoras/metabolismo , Diosgenina/farmacologia , Diosgenina/metabolismo , Células CACO-2 , Lipopolissacarídeos , Camundongos Endogâmicos C57BL , Intestinos , Colesterol , Dieta , Ezetimiba/farmacologia , Ezetimiba/metabolismo , Fígado/metabolismoRESUMO
MicroRNAs (miRNAs) play important roles in posttranscriptional regulation and may serve as targets for the diagnosis and treatment of cancers. Nevertheless, a comprehensive understanding of miRNAs profiles in gastric cancer progression is still lacking. Here, we report that miR-129-5p is downregulated in gastric cancer by analyzing TCGA database (n = 41) and clinical tumor samples (n = 60). MiR-129-5p transfection suppressed gastric cancer cell proliferation through inducing G1 phase arrest in vitro and inhibit xenograft tumor growth in vivo. MiR-129-5p directly targeted the 3' untranslated regions (3' UTR) of HOXC10 mRNA and downregulated its expression. Importantly, miR-129-5p could reverse the oncogenic effect induced by HOXC10. We systemically screened the downstream target of HOXC10 by ChIP sequencing, and found that HOXC10 could transcriptionally regulate the expression of Cyclin D1 and facilitate G1/S cell cycle transition. Notably, high levels of HOXC10 and Cyclin D1 were related with poor prognosis of gastric cancer patients (n = 90). These findings reveal a novel role of miR-129-5p/HOXC10/Cyclin D1 axis in modulating cell cycle and gastric tumorigenesis, which might provide potential prognostic biomarkers and therapeutic targets for gastric cancer patients.
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Pontos de Checagem do Ciclo Celular/genética , Ciclina D1/genética , Proteínas de Homeodomínio/genética , MicroRNAs/genética , Neoplasias Gástricas/genética , Regiões 3' não Traduzidas/genética , Animais , Linhagem Celular , Linhagem Celular Tumoral , Proliferação de Células/genética , Progressão da Doença , Regulação para Baixo/genética , Feminino , Fase G1/genética , Regulação Neoplásica da Expressão Gênica/genética , Células HEK293 , Humanos , Camundongos , Camundongos Endogâmicos BALB C , Oncogenes/genética , Fase S/genética , Estômago/patologiaRESUMO
Chiral alcohols are important building blocks in the pharmaceutical and fine chemical industries. The enantioselective reduction of prochiral ketones catalyzed by transition metal complexes, especially asymmetric transfer hydrogenation (ATH) and asymmetric hydrogenation (AH), is one of the most efficient and practical methods for producing chiral alcohols. In both academic laboratories and industrial operations, catalysts based on noble metals such as ruthenium, rhodium, and iridium dominated the asymmetric reduction of ketones. However, the limited availability, high price, and toxicity of these critical metals demand their replacement with abundant, nonprecious, and biocommon metals. In this respect, the reactions catalyzed by first-row transition metals, which are more abundant and benign, have attracted more and more attention. As one of the most abundant metals on earth, iron is inexpensive, environmentally benign, and of low toxicity, and as such it is a fascinating alternative to the precious metals for catalysis and sustainable chemical manufacturing. However, iron catalysts have been undeveloped compared to other transition metals. Compared with the examples of iron-catalyzed asymmetric reduction, cobalt- and nickel-catalyzed ATH and AH of ketones are even seldom reported. In early 2004, we reported the first ATH of ketones with catalysts generated in situ from iron cluster complex and chiral PNNP ligand. Since then, we have devoted ourselves to the development of ATH and AH of ketones with iron, cobalt, and nickel catalysts containing novel chiral aminophosphine ligands. In our study, the iron catalyst containing chiral aminophosphine ligands, which are expected to control the stereochemistry at the metal atom, restrict the number of possible diastereoisomers, and effectively transfer chiral information, are successful catalysts for enantioselective reduction of ketones. Among these novel chiral aminophosphine ligands, 22-membered macrocycle P2N4 exhibited extraordinary enantioselectivities when combined with iron(0) cluster Fe3(CO)12. A broad scope of ketones including aromatic, heteroaromatic, and ß-ketoesters can be reduced smoothly with excellent enantioselectivities (up to 99% ee) approaching or exceeding those achievable with the noble metal catalysts. Notably, the chiral iron-based catalyst proved to be highly efficient for both ATH as well as AH of various ketones. Until now, such "universal" catalyst is very rare. Preliminary studies suggest that the AH reaction most likely involved iron particles as the active catalytic species. These research results point to a new direction in developing viable effective nonprecious metal catalysts for asymmetric reduction and probably for other asymmetric catalytic reactions as well.
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We report herein the design and synthesis of a series of novel 5-bromo-7-azaindolin-2-one derivatives containing a 2,4-dimethyl-1H-pyrrole-3-carboxamide moiety. These newly synthesized derivatives were evaluated for in vitro activity against selected cancer cell lines by MTT assay. Results revealed that some compounds exhibit broad-spectrum antitumor potency, and the most active compound 23p (IC50: 2.357-3.012 µM) was found more potent than Sunitinib (IC50: 31.594-49.036 µM) against HepG2, A549 and Skov-3, respectively.
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Antineoplásicos/síntese química , Compostos Aza/síntese química , Indóis/síntese química , Pirróis/síntese química , Células A549 , Antineoplásicos/farmacologia , Compostos Aza/farmacologia , Sobrevivência Celular/efeitos dos fármacos , Ensaios de Seleção de Medicamentos Antitumorais , Células Hep G2 , Humanos , Indóis/farmacologia , Pirróis/farmacologia , SunitinibeRESUMO
We report herein the design and synthesis of a series of novel imidazo[1,2-a]pyridine amide-cinnamamide hybrids linked via an alkyl carbon chain. All 38 new hybrids were evaluated for their antimycobacterial activity against M. tuberculosis (MTB) H37Rv ATCC 27294 using the microplate Alamar Blue assay (MABA). Although the hybrids are less active than the two reference compounds, the promising activity (MICs: 4 µg/mL) of 2,6-dimethylimidazo[1,2-a]pyridine amide-cinnamamide hybrids 11e and 11k could be a good starting point to further find new lead compounds against multi-drug-resistant tuberculosis.
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Cinamatos/síntese química , Mycobacterium tuberculosis/efeitos dos fármacos , Piridinas/síntese química , Anti-Infecciosos/síntese química , Anti-Infecciosos/química , Anti-Infecciosos/farmacologia , Cinamatos/química , Cinamatos/farmacologia , Farmacorresistência Bacteriana Múltipla/efeitos dos fármacos , Testes de Sensibilidade Microbiana , Estrutura Molecular , Piridinas/química , Piridinas/farmacologia , Relação Estrutura-AtividadeRESUMO
Chiral molecules, such as alcohols, are vital for the manufacturing of fine chemicals, pharmaceuticals, agrochemicals, fragrances, and novel materials. These molecules need to be produced in high yield and high optical purity and preferentially catalytically. Among all the asymmetric catalytic reactions, asymmetric hydrogenation with H2 (AH) is the most widely used in the industry. With few exceptions, these AH processes use catalysts based on the three critical metals, rhodium, ruthenium, and iridium. Herein we describe a simple, industrially viable iron catalyst that allows for the AH of ketones, a process currently dominated by ruthenium and rhodium catalysts. By combining a chiral, 22-membered macrocyclic ligand with the cheap, readily available Fe3(CO)12, a wide variety of ketones have been hydrogenated under 50 bar H2 at 45-65 °C, affording highly valuable chiral alcohols with enantioselectivities approaching or surpassing those obtained with the noble metal catalysts. In contrast to AH by most noble metal catalysts, the iron-catalyzed hydrogenation appears to be heterogeneous.
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BACKGROUND: The rise of linezolid resistance has been widely observed both in clinical and non-clinical settings. However, there were still data gaps regarding the comprehensive prevalence and interconnections of linezolid resistance genes across various niches. RESULTS: We screened for potential linezolid resistance gene reservoirs in the intestines of both humans and animals, in meat samples, as well as in water sources. A total of 796 bacteria strains out of 1538 non-duplicated samples were identified to be positive for at least one linezolid resistance gene, optrA, poxtA, cfr, and cfr(D). The prevalence of optrA reached 100% (95% CI 96.3-100%) in the intestines of pigs, followed by fish, ducks, and chicken at 77.5% (95% CI 67.2-85.3%), 62.0% (95% CI 52.2-70.9%), and 61.0% (95% CI 51.2-70.0%), respectively. The meat and water samples presented prevalences of 80.0% (95% CI 70.6-87.0%) and 38.0% (95% CI 25.9-51.9%), respectively. The unreported prevalence of the cfr(D) gene was also relatively higher at 13.0% (95% CI 7.8-21.0%) and 19.0% (95% CI 10.9-25.6%) for the feces samples of ducks and pigs, respectively. Enterococci were the predominant hosts for all genes, while several non-enterococcal species were also identified. Phylogenetic analysis revealed a significant genetic distance among linezolid resistance gene reservoirs, with polyclonal structures observed in strains within the same niche. Similar genetic arrays harboring assorted insertion sequences or transposons were shared by reservoirs displaying heterogeneous backgrounds, though large diversity in the genetic environment of linezolid resistance genes was also observed. CONCLUSIONS: The linezolid resistance genes were widespread among various niches. The horizontal transfer played a crucial role in driving the circulation of linezolid resistance reservoirs at the human-animal-environment interfaces. Video Abstract.
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Antibacterianos , Enterococcus faecium , Humanos , Animais , Suínos , Linezolida/farmacologia , Antibacterianos/farmacologia , Filogenia , Enterococcus faecalis/genética , Enterococcus faecium/genética , Farmacorresistência Bacteriana/genética , Patos , Água , Testes de Sensibilidade MicrobianaRESUMO
BACKGROUND: The intake of high-fructose corn syrup (HFCS) may increase the risk of colorectal cancer (CRC). This study aimed to explore the potential effects and mechanisms of resistant starch (RS) in HFCS-induced colon tumorigenesis. METHODS: The azoxymethane/dextran sodium sulfate (AOM/DSS) and ApcMin/+ mice models were used to investigate the roles of HFCS and RS in CRC in vivo. An immunohistochemistry (IHC) staining analysis was used to detect the expression of proliferation-related proteins in tissues. 16S rRNA sequencing for microbial community, gas chromatography for short-chain fatty acids (SCFAs), and mass spectrometry analysis for glycolysis products in the intestines were performed. Furthermore, lactic acid assay kit was used to detect the glycolysis levels in vitro. RESULTS: RS suppressed HFCS-induced colon tumorigenesis through reshaping the microbial community. Mechanistically, the alteration of the microbial community after RS supplement increased the levels of intestinal SCFAs, especially butyrate, leading to the suppression of glycolysis and CRC cell proliferation by downregulating HK2. CONCLUSIONS: Our study identified RS as a candidate of protective factors in CRC and may provide a potential target for HFCS-related CRC treatment.
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Introduction: Ceftazidime/avibactam (CZA) is an effective alternative for the treatment of infections caused by KPC-producing carbapenem-resistant Klebsiella pneumoniae (CRKP). However, KPC variants with CZA resistance have been observed in clinical isolates, further limiting the treatment options of clinical use. Methods: In this study, we isolated three KPC-14-producing CRKP from two patients in intensive care units without CZA therapy. The antimicrobial susceptibility was determined using the broth microdilution method. Three CRKP were subjected to whole-genome sequencing to analyze the phylogenetic relatedness and the carriage of antimicrobial resistance genes and virulence factors. Long-read sequencing was also performed to obtain the complete sequences of the plasmids. The horizontal transfer of the blaKPC-14 gene was evaluated by conjugation experiments. Results: Three CRKP displayed resistance or reduced susceptibility to ceftazidime/avibactam, colistin, and tigecycline. Single-nucleotide polymorphism (SNP) analysis demonstrated the close phylogenetic distance between these strains. A highly similar IncFII/IncR plasmid encoding blaKPC-14 was shared by three CRKP, with blaKPC-14 located in an NTEKPC-Ib element with the core region of ISKpn27- blaKPC-14-ISKpn6. This structure containing blaKPC-14 was also observed in another tet(A)-carrying plasmid that belonged to an unknown Inc-type in two out of three isolates. The horizontal transferability of these integrated plasmids to Escherichia coli EC600 was confirmed by the cotransmission of tet(A) and blaKPC-14 genes, but the single transfer of blaKPC-14 on the IncFII/IncR plasmid failed. Three CRKP expressed yersiniabactin and carried a hypervirulence plasmid encoding rmpA2 and aerobactin-related genes, and were thus classified as carbapenem-resistant hypervirulent K. pneumoniae (hvKP). Discussion: In this study, we reported the evolution of a mosaic plasmid encoding the blaKPC-14 gene via mobile elements in extensively drug-resistant hvKP. The blaKPC-14 gene is prone to integrate into other conjugative plasmids via the NTEKPC-Ib element, further facilitating the spread of ceftazidime/avibactam resistance.
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Pseudomonas aeruginosa is one of the most common opportunistic pathogens causing severe nosocomial infections for its patterns of multidrug resistance, particularly for carbapenems. Timely epidemiological surveillance could greatly facilitate infection control of P. aeruginosa and many deadly pathogens alike. IR Biotyper (IRBT), is a novel real-time typing tool, based on a Fourier-transform infrared (FTIR) spectroscopy system. It is critical to comprehensively establish and evaluate the feasibility of IRBT in P. aeruginosa strain typing. In the current study, we first established standards and schemes for its routine laboratory application, and we found that Mueller-Hinton agar plates give better discriminatory power than blood agar plates. Data showed that the cut-off value of 0.15 with an additional 0.025 range was optimal. Secondly, 27 clinically isolated carbapenem-resistant P. aeruginosa (CRPA) strains collected from October 2010 to September 2011 were evaluated for typing effectiveness by comparing IRBT to the other commonly used typing methods, such as multi-locus sequence typing (MLST), pulsed-field gel electrophoresis (PFGE) and whole-genome sequencing (WGS)-based typing. When using WGS-based typing as the reference method, the typing method of FTIR spectroscopy (AR = 0.757, SID = 0.749) could better cluster P. aeruginosa strains than MLST and in silico serotyping (AR = 0.544, SID = 0.470). Though PFGE showed the highest discriminatory power, low concordance was observed between PFGE and the other methods. Above all, this study demonstrates the utility of the IRBT as a quick, low-cost, real-time typing tool for the detection of CRPA strains.
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Linezolid resistance has represented a global concern with its wide dissemination among nosocomial pathogens in recent years. One hundred and two linezolid-resistant Staphylococcus capitis (LRSC) were constantly isolated from 2011 to 2021, which demonstrated single clonal dissemination in a Chinese tertiary hospital. A structurally similar cfr-carrying plasmid was identified among 90 isolates. A chromosomal cfr was located beside a Tn4001-like transposon and ISEnfa4 in one strain (LR95). The loss of cfr-carrying plasmid was observed in 11 isolates and the in vitro passage experiments. Conjugation experiments demonstrated the horizontal transferability of the cfr-carrying plasmid into Staphylococcus aureus RN4220. Both cfr-positive LRSC and S. aureus showed no significant differences in growth rates, while only the former displayed competition defect, suggesting this plasmid imposed a certain fitness cost on LRSC. Hence, ongoing measurements are supposed to be adopted to control the spread of these antimicrobial-resistant bacteria.
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The linezolid resistance mediated by optrA has exhibited an increasing trend among Gram-positive bacteria, which greatly limits the treatment options for severe bacterial infections. However, the prevalence of optrA was usually underestimated based on the existing screening methods. In this study, we used a traditional method and an improved method that included a high-salinity condition treatment after enrichment to screen for optrA-carrying bacteria from stool samples from 1,018 healthy donors in Hangzhou, China. The fecal carriage rate of optrA-carrying bacteria was 19.25% when screened by the improved method (196/1,018), which was much higher than that of the traditional method at 5.89% (60/1,018). Enterococci were the majority of the optrA-positive isolates, while five nonenterococcal isolates were also obtained, including two Streptococcus gallolyticus, one Vagococcus lutrae, one Lactococcus garvieae, and one Lactococcus formosensis isolate. Whole-genome sequencing analysis identified four novel OptrA variants, IDKKGPM, IDKKGP, KLDK, and EYDDI, in these isolates, whose optrA-flanking regions with a fexA gene downstream were bounded by different insertion sequences. In conclusion, our optimized method displayed high sensitivity in the detection of optrA-positive bacteria in fecal samples and revealed a high carriage rate in a healthy population. Although enterococci are dominant, multiple optrA-carrying Gram-positive bacteria were also found. IMPORTANCE This study represented an optimized screening approach for the optrA gene, which is an important mechanism of antimicrobial resistance to linezolid as a last resort for the treatment of infections caused by multiresistant Gram-positive bacteria. We revealed a high fecal carriage rate of the optrA gene among adults by this method and reported the first identification of optrA in Lactococcus formosensis as well as the identification of this gene in Vagococcus lutrae and of the poxtA gene in Ligilactobacillus salivarius of human origin, suggesting the wide spread of the optrA gene in the Gram-positive bacterial community.
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Enterococcus faecium , Infecções por Bactérias Gram-Positivas , Oxazolidinonas , Adulto , Humanos , Oxazolidinonas/farmacologia , Linezolida , Antibacterianos/farmacologia , Enterococcus faecalis/genética , Farmacorresistência Bacteriana/genética , Enterococcus/genética , Infecções por Bactérias Gram-Positivas/diagnóstico , Infecções por Bactérias Gram-Positivas/epidemiologia , Infecções por Bactérias Gram-Positivas/microbiologia , Testes de Sensibilidade MicrobianaRESUMO
Dissemination of the Klebsiella pneumoniae carbapenemase (KPC)-encoding gene among Enterobacterales is common but relatively rare in Aeromonas spp. In this study, we characterized two KPC-2-producing Aeromonas hydrophila strains (Ah2101 and Ah2111), each isolated from a patient in different intensive care units (ICUs) of a Chinese hospital. Whole-genome sequencing (WGS) revealed simultaneous carriage of the bla KPC-2 and imiH genes, both of which encode high-level carbapenem resistance in these two A. hydrophila isolates. The two isolates were shown to be clonally related and each isolate harbored two distinguishable bla KPC-2-bearing plasmids, only one of which was transferrable to A. hydrophila, but not Escherichia coli EC600 via conjugation. The genetic element that contains bla KPC-2 in these two plasmids, namely ISKpn27-Δbla TEM-1-bla KPC-2-ISKpn6, was structurally identical, commonly detected in Enterobacterales, and associated with Tn3-based transposons. In addition, more than sixty putative genes that encode various virulence factors were identified in these two A. hydrophila isolates. This is the first study that reports clonal dissemination of carbapenem-resistant A. hydrophila strains carrying structurally different bla KPC-2-bearing plasmids. Further investigation is warranted to monitor the future transmission of bla KPC-2-bearing plasmids in A. hydrophila in clinical settings.
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This study reported the identification of a novel ceftazidime-avibactam-resistant KPC-2 variant, KPC-123, in a Citrobacter koseri isolated from a patient in a Chinese hospital following ceftazidime-avibactam treatment of infection caused by OXA-232-producing Klebsiella pneumoniae. This novel KPC-123 consisting of 302 amino acids differs from KPC-2 by two insertions after positions 179 (ins179_TY) and 270 (ins270_DDKHSEA), respectively. Conjugation and cloning experiments confirmed that KPC-123 was able to confer high-level resistance to ceftazidime and ceftazidime/avibactam (MICs of 128 mg/L and 64/4 mg/L, respectively) and elevated MIC values of cefotaxime, cefepime, and aztreonam (4 mg/L, 2 mg/L, and 4 mg/L, respectively) but retained susceptibility to carbapenems. Whole-genome sequencing and genomic analysis revealed that bla KPC-123 within the "ISKpn27-bla KPC-ISKpn6" structure was located on a 93,814-bp conjugative plasmid that was almost identical to a bla KPC-2-carrying plasmid harbored in a K. pneumoniae isolate from the same sampling site of the patient, suggesting the transfer and in vivo evolution of this bla KPC-carrying plasmid. Hence, active surveillance of ceftazidime/avibactam resistance and the underlying mechanisms, which may facilitate the prevention and control of the dissemination of resistance, is needed.
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Recently, there has been an increase in the incidence of malignant tumors among the older population. Moreover, there is an association between aging and cancer. During the process of senescence, the human body suffers from a series of imbalances, which have been shown to further accelerate aging, trigger tumorigenesis, and facilitate cancer progression. Therefore, exploring the junctions of aging and cancer and searching for novel methods to restore the junctions is of great importance to intervene against aging-related cancers. In this review, we have identified the underlying pathogenetic mechanisms of aging-related cancers by comparing alterations in the human body caused by aging and the factors that trigger cancers. We found that the common mechanisms of aging and cancer include cellular senescence, alterations in proteostasis, microbiota disorders (decreased probiotics and increased pernicious bacteria), persistent chronic inflammation, extensive immunosenescence, inordinate energy metabolism, altered material metabolism, endocrine disorders, altered genetic expression, and epigenetic modification. Furthermore, we have proposed that aging and cancer have common means of intervention, including novel uses of common medicine (metformin, resveratrol, and rapamycin), dietary restriction, and artificial microbiota intervention or selectively replenishing scarce metabolites. In addition, we have summarized the research progress of each intervention and revealed their bidirectional effects on cancer progression to compare their reliability and feasibility. Therefore, the study findings provide vital information for advanced research studies on age-related cancers. However, there is a need for further optimization of the described methods and more suitable methods for complicated clinical practices. In conclusion, targeting aging may have potential therapeutic effects on aging-related cancers.
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Cholesterol gallstone disease is a common global condition. This study investigated the role of plant sterols (PS) in the prevention of gallstone formation and the underlying mechanisms. Adult male mice were fed a lithogenic diet (LD) alone or supplemented with PS (LD-ps), phospholipids (LD-pl) or both PS and phospholipids (LD-ps/pl) for 8 weeks. Incidences of gallstone formation were compared among the groups. Lipids in the bile, liver and serum were analyzed. The expression of genes involved in cholesterol absorption, transport and metabolism in the liver and small intestine was determined. The incidences of gallstone formation were 100% (10/10), 20% (2/10), 100% (10/10) and 40% (4/10) in the LD, LD-ps, LD-pl and LD-ps/pl groups, respectively. Serum cholesterol and intestinal cholesterol absorption were decreased in PS-supplemented mice. The expression of genes related to cholesterol transport and metabolism in the liver was down-regulated by dietary PS. PS supplementation decreased Niemann-Pick C1-like 1 expression in the small intestine and reduced intestinal cholesterol absorption. Our results demonstrated that PS could inhibit intestinal cholesterol absorption and thus prevent cholesterol gallstone formation.
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Colesterol/metabolismo , Cálculos Biliares/prevenção & controle , Absorção Intestinal/efeitos dos fármacos , Fitosteróis/farmacologia , Animais , Colesterol/administração & dosagem , Colesterol/efeitos adversos , Dieta , Suplementos Nutricionais , Masculino , Camundongos , Camundongos Endogâmicos C57BLRESUMO
Background: Hepatic lipid metabolism regulates biliary composition and influences the formation of cholesterol gallstones. The genes Hmgcr and Cyp7a1, which encode key liver enzymes, are regulated by circadian rhythm-related transcription factors. We aimed to investigate the effect of circadian rhythm disruption on hepatic cholesterol and bile acid metabolism and the incidence of cholesterol stone formation. Methods: Adult male C57BL/6J mice were fed either a lithogenic diet (LD) only during the sleep phase (time-restricted lithogenic diet feeding, TRF) or an LD ad libitum (non-time-restricted lithogenic diet feeding, nTRF) for 4 weeks. Food consumption, body mass gain, and the incidence of gallstones were assessed. Circulating metabolic parameters, lipid accumulation in the liver, the circadian expression of hepatic clock and metabolic genes, and the gut microbiota were analyzed. Results: TRF caused a dysregulation of the circadian rhythm in the mice, characterized by significant differences in the circadian expression patterns of clock-related genes. In TRF mice, the circadian rhythms in the expression of genes involved in bile acid and cholesterol metabolism were disrupted, as was the circadian rhythm of the gut microbiota. These changes were associated with high biliary cholesterol content, which promoted gallstone formation in the TRF mice. Conclusion: Disordered circadian rhythm is associated with abnormal hepatic bile acid and cholesterol metabolism in mice, which promotes gallstone formation.