Genetic Diversity of Polymyxin-Resistance Mechanisms in Clinical Isolates of Carbapenem-Resistant Klebsiella pneumoniae: a Multicenter Study in China.

Polymyxin has been the last resort to treat multidrug-resistant Klebsiella pneumonia. However, recent studies have revealed that polymyxin-resistant carbapenem-resistant Klebsiella pneumonia (PR-CRKP) emerged due to the mutations in chromosomal genes or the plasmid-harboring mcr gene, leading to lipopolysaccharide modification or efflux of polymyxin through pumps. Further surveillance was required. In the present study we collected PR-CRKP strains from 8 hospitals in 6 provinces/cities across China to identify the carbapenemase and polymyxin resistance genes and epidemiological features by whole-genome sequencing (WGS). The broth microdilution method (BMD) was performed to determine the MIC of polymyxin. Of 662 nonduplicate CRKP strains, 15.26% (101/662) were defined as PR-CRKP; 10 (9.90%) were confirmed as Klebsiella quasipneumoniae by WGS. The strains were further classified into 21 individual sequence types (STs) by using multilocus sequence typing (MLST), with ST11 being prevalent (68/101, 67.33%). Five carbapenemase types were identified among 92 CR-PRKP, blaKPC-2 (66.67%), blaNDM-1 (16.83%), blaNDM-5 (0.99%), blaIMP-4 (4.95%), and blaIMP-38 (0.99%). Notably, 2 PR-CRKP strains harbored both blaKPC-2 and blaNDM-1. The inactivation of mgrB, associated significantly with high-level polymyxin resistance, was mainly caused by the insertion sequence (IS) insertion (62.96%, 17/27). Furthermore, acrR was inserted coincidently by ISkpn26 (67/101, 66.33%). The deletion or splicing mutations of crrCAB were significantly associated with ST11 and KL47 (capsule locus types), and diverse mutations of the ramR gene were identified. Only one strain carried the mcr gene. In summary, the high IS-inserted mgrB inactivation, the close relationship between ST11 and the deletion or splicing mutations of the crrCAB, and the specific features of PR-K. quasipneumoniae constituted notable features of our PR-CRKP strains in China. IMPORTANCE Polymyxin-resistant CRKP is a serious public health threat whose resistance mechanisms should be under continuous surveillance. Here, we collected 662 nonduplicate CRKP strains across China to identify the carbapenemase and polymyxin resistance genes and epidemiological features. Polymyxin resistance mechanism in 101 PR-CRKP strains in China were also investigated, 9.8% of which (10/101) were K. quasipneumoniae, as determined via WGS, and inactivation of mgrB remained the most crucial polymyxin resistance mechanism, significantly related to high-level resistance. Deletion or splicing mutations of crrCAB were significantly associated with ST11 and KL47. Diverse mutations of the ramR gene were identified. The plasmid complementation experiment and mRNA expression analysis further confirmed that the mgrB promoter and ramR played a critical role in polymyxin resistance. This multicenter study contributed to the understanding of antibiotic resistance forms in China.

Analysis of distribution characteristics and drug resistance of pathogens isolated from ascites of patients in Children's Hospital Affiliated to Zhengzhou University, 2015-2021 / 中国热带医学

@#Abstract: Objective　To investigate the distribution and drug resistance of pathogenic bacteria separated from ascites of patients in Children’s Hospital Affiliated to Zhengzhou University from 2015 to 2021, and to provide a basis for rational clinical antimicrobial agents. Methods　Bacterial culture, bacterial identification and drug sensitivity analysis were performed on 1 058 non-duplicate ascites culture specimens from January 2015 to December 2021. The clinica1 and microbiologica1 data were ana1yzed by WHONET 5.6 and SAS 9.4 Results　Of the 1 058 specimens, 586 (55.39%) were positive for pathogenic bacteria, with a total of 781 strains isolated. There was no significant trend of increase or decrease in the positivity rate over different years. Male children (63.99%) were more prevalent than female children. Appendicitis (59.22%) was the most common disease and Escherichia coli was the most common causative bacteria. Among neonates (≤28 d), the bacteria with the highest detection rate were Klebsiella pneumoniae (23.50%) and Enterococcus faecium (23.50%), while among children (>28 d), the highest detection rate was Escherichia coli (35.98%). Gram-negative bacteria accounted for 64.79% of the 781 strains, mainly Escherichia coli (38.28%), Klebsiella pneumoniae (8.58%), and Pseudomonas aeruginosa (5.89%); Gram-positive bacteria accounted for 29.45%, mainly Enterococcus faecium (8.58%), Streptococcus constellatus (2.69%), and Enterococcus avium (2.43%); fungi accounted for 1.66% and anaerobic bacteria accounted for 4.10%. The resistance rates of Escherichia coli to cefoperazone/sulbactam, piperacillin/tazobactam, imipenem and meropenem were 6.02%, 4.35%, 4.35%, and 3.68%, respectively. The resistance rates of Klebsiella pneumoniae to these drugs were 59.70%, 59.70%, 50.75% and 53.73% respectively. Linezolid-resistant strains of Enterococcus faecium were found. Conclusion　Appendicitis is the most common abdominal infection in children, and the distribution of ascites pathogens varies with ages and diseases. The pathogenic bacteria are mainly Gram-negative bacteria, and the drug resistance of Klebsiella pneumoniae was more serious. It is particularly important to use antibiotics correctly and rationally to reduce the emergence of drug resistant bacteria.

Prediction of stock price direction using the LASSO-LSTM model combines technical indicators and financial sentiment analysis.

Correctly predicting the stock price movement direction is of immense importance in the financial market. In recent years, with the expansion of dimension and volume in data, the nonstationary and nonlinear characters in finance data make it difficult to predict stock movement accurately. In this article, we propose a methodology that combines technical analysis and sentiment analysis to construct predictor variables and then apply the improved LASSO-LASSO to forecast stock direction. First, the financial textual content and stock historical transaction data are crawled from websites. Then transfer learning Finbert is used to recognize the emotion of textual data and the TTR package is taken to calculate the technical indicators based on historical price data. To eliminate the multi-collinearity of predictor variables after combination, we improve the long short-term memory neural network (LSTM) model with the Absolute Shrinkage and Selection Operator (LASSO). In predict phase, we apply the variables screened as the input vector to train the LASSO-LSTM model. To evaluate the model performance, we compare the LASSO-LSTM and baseline models on accuracy and robustness metrics. In addition, we introduce the Wilcoxon signed rank test to evaluate the difference in results. The experiment result proves that the LASSO-LSTM with technical and sentiment indicators has an average 8.53% accuracy improvement than standard LSTM. Consequently, this study proves that utilizing historical transactions and financial sentiment data can capture critical information affecting stock movement. Also, effective variable selection can retain the key variables and improve the model prediction performance.

Clinical profiles and antimicrobial resistance patterns of invasive Salmonella infections in children in China.

Invasive Salmonella infections result in a significant burden of disease including morbidity, mortality, and financial cost in many countries. Besides typhoid fever, the clinical impact of non-typhoid Salmonella infections is increasingly recognized with the improvement of laboratory detection capacity and techniques. A retrospective multicenter study was conducted to analyze the clinical profiles and antimicrobial resistance patterns of invasive Salmonella infections in hospitalized children in China during 2016-2018. A total of 130 children with invasive Salmonella infections were included with the median age of 12 months (range: 1-144 months). Seventy-nine percent of cases occurred between May and October. Pneumonia was the most common comorbidity in 33 (25.4%) patients. Meningitis and septic arthritis caused by nontyphoidal Salmonella (NTS) infections occurred in 12 (9.2%) patients and 5 (3.8%) patients. Patients < 12 months (OR: 16.04) and with septic shock (OR: 23.4), vomit (OR: 13.33), convulsion (OR: 15.86), C-reactive protein (CRP) ≥ 40 g/L (OR: 5.56), and a higher level of procalcitonin (PCT) (OR: 1.05) on admission were statistically associated to an increased risk of developing meningitis. Compared to 114 patients with NTS infections, 16 patients with typhoid fever presented with higher levels of CRP and PCT (P < 0.05). The rates of resistance to ampicillin, sulfamethoxazole/trimethoprim, ciprofloxacin, and ceftriaxone among Salmonella Typhi and NTS isolates were 50% vs 57.3%, 9.1% vs 24.8%, 0% vs 11.2%, and 0% vs 9.9%, respectively. NTS has been the major cause of invasive Salmonella infections in Chinese children and can result in severe diseases. Antimicrobial resistance among NTS was more common.

MicroRNA-182-5p aggravates ulcerative colitis by inactivating the Wnt/ß-catenin signaling pathway through DNMT3A-mediated SMARCA5 methylation.

This research focused on novel molecular mechanisms underlying microRNA (miR)-182-5p in ulcerative colitis (UC). Colon tissues were obtained from UC patients, and dextrose sodium sulfate (DSS)-induced mouse and interleukin-1ß (IL-1ß)-induced Caco-2 cell models were generated. Then, miR-182-5p, SMARCA5, and the Wnt/ß-catenin signaling pathway were altered in IL-1ß-stimulated Caco-2 cells and DSS-treated mice to assess their function. MiR-182-5p and SMARCA5 were upregulated and DNMT3A, ß-catenin, and Cyclin D1 were downregulated in UC patients, IL-1ß-stimulated Caco-2 cells, and DSS-treated mice. Mechanistically, miR-182-5p targeted DNMT3A to upregulate SMARCA5, thus blocking the Wnt/ß-catenin signaling pathway. Moreover, SMARCA5 silencing or Wnt/ß-catenin signaling pathway activation repressed apoptosis and augmented proliferation and epithelial barrier function of IL-1ß-stimulated Caco-2 cells. SMARCA5 silencing annulled the impacts of miR-182-5p overexpression on IL-1ß-stimulated Caco-2 cells. SMARCA5 silencing or miR-182-5p inhibition ameliorated intestinal barrier dysfunction in DSS-treated mice. Collectively, miR-182-5p aggravates UC by inactivating the Wnt/ß-catenin signaling pathway through DNMT3A-mediated SMARCA5 methylation.

Comparative Genomic Analysis of Streptococcus pneumoniae Strains: Penicillin Non-susceptible Multi-drug-Resistant Serotype 19A Isolates.

Streptococcus pneumoniae can cause several diseases including otitis media, sinusitis, pneumonia, sepsis and meningitis. The introduction of pneumococcal vaccines has changed the molecular epidemiological and antibiotic resistance profiles of related diseases. Analysis of molecular patterns and genome sequences of clinical strains may facilitate the identification of novel drug resistance mechanism. Three multidrug resistance 19A isolates were verified, serotyped and the complete genomes were sequenced combining the Pacific Biosciences and the Illumina Miseq platform. Genomic annotation revealed that similar central networks were found in the clinical isolates, and Mauve alignments indicated high similarity between different strains. The pan-genome analysis showed the shared and unique cluster in the strains. Mobile elements were predicted in the isolates including prophages and CRISPER systems, which may participate in the virulence and antibiotic resistance of the strains. The presence of 31 virulence factor genes was predicted from other pathogens for PRSP 19339 and 19343, while 30 for PRSP 19087. Meanwhile, 33 genes antibiotic resistance genes were predicted including antibiotic resistance genes, antibiotic-target genes and antibiotic biosynthesis genes. Further analysis of the antibiotic resistance genes revealed new mutations in the isolates. By comparative genomic analysis, we contributed to the understanding of resistance mechanism of the clinical isolates with other serotype strains, which could facilitate the concrete drug resistance mechanism study.

Circular RNA HECTD1 Mitigates Ulcerative Colitis by Promoting Enterocyte Autophagy Via miR-182-5p/HuR Axis.

OBJECTIVE: Ulcerative colitis (UC) is a chronic colitis with unknown etiology. Circular RNA (circRNA) has shown regulatory effect in many diseases, but the role of circRNA in UC is barely known. This study uncovers the function and regulatory mechanism of circRNA HECTD1 (circHECTD1) in UC. METHODS: Colonic mucosal tissues of 60 patients with active UC and 30 healthy controls were collected for H&E staining. Lipopolysaccharide (LPS) and dextran sulfate sodium (DSS) were used to induce inflammation and UC in Caco-2 cells and C57BL/6 mice where modification of circHECTD1, miR-182-5p and/or human antigen R (HuR) took place. The Caco-2 cells and the colon tissues of DSS-treated mice were collected for analysis of the expression levels of inflammatory cytokines, NLRP3 inflammasome, and autophagy-related proteins. The interactions among circHECTD1, miR-182-5p, and HuR were verified. RESULTS: The colonic mucosal tissues of UC patients showed impaired autophagy and decreased expressions of circHECTD1 and HuR. Overexpression of circHECTD1 or HuR or inhibition of miR-182-5p suppressed inflammation and promoted autophagy of LPS-induced Caco-2 cells. The expression of HuR was promoted by circHECTD1 via miR-182-5p in Caco-2 cells. Overexpression of circHECTD1 reduced colonic injuries and inflammation by promoting autophagy in DSS-treated mice. CONCLUSION: Overexpression of circHECTD1 alleviates UC by promoting HuR-dependent autophagy via miR-182-5p. This study highlights the therapeutic potential of circHECTD1 for UC and adds to the knowledge of circRNA in the pathogenesis of UC.

Carbapenem-Resistant Klebsiella pneumoniae Osteomyelitis Treated with Ceftazidime-Avibactam in an Infant: A Case Report.

Increasing cases of carbapenem-resistant Klebsiella pneumoniae (CR-KP) infections have been observed globally where multi-drug resistance to CR-KP can make the infection difficult to treat. In recent years, the ß-lactam/ß-lactamase inhibitor, ceftazidime-avibactam (CAZ-AVI), has been developed to treat complicated urinary tract infections and complicated intra-abdominal infections. CAZ-AVI is approved for children over 3-month old but has yet to be investigated for cases of osteomyelitis. Only three case reports exist in literature on the use of CAZ-AVI for CR-KP osteomyelitis in adults. In this report, we present an infant with primary hematogenous osteomyelitis and septic arthritis in the right shoulder following surgical treatment for a heart murmur. Bacterial isolation revealed a strain of CR-KP, which was successfully treated with CAZ-AVI after initial administration of imipenem-based treatments.

The complete chloroplast genome of a medicinal plant Viscum articulatum Burm.f. (Loranthaceae).

Viscum articulatum is usually used as famous ethno-medicinal plant and popular drink in many provinces of China. In this study, the characterization of the complete chloroplast genome of V. articulatum was analyzed using the Illumina NovaSeq platform. The whole chloroplast genome sequence of V. articulatum is 131,825 including a large single-copy region (LSC, 76,069 bp), a small single-copy region (SSC, 8990 bp), and a pair of repeated regions (IRs, 23,383 bp, each). Further gene annotation in our study revealed the chloroplast genome contains 114 genes, including 36 tRNA genes, 8 rRNA genes and 70 protein-coding genes. A total of 118 simple sequence repeats (SSRs) were identified in the chloroplast genome. Phylogenetic development was analyzed based on V. articulatum with other species of Loranthaceae, the phylogenetic tree in our study revealed that V. articulatum is a lineage independent of other species in genus Viscum.

Interaction Mechanisms between Lithium Polysulfides/Sulfide and Small Organic Molecules.

Lithium polysulfides (LiPSs)/sulfide are essential in secondary lithium batteries. In this work, we used density functional theory computational methods to obtain the law of constraining lithium polysulfides/sulfide by the affinitive interactions at the electronic level. The proton transfer, the orientation of polysulfides, the electron affinity, and the acid dissociation constant of small organic molecules were examined to elucidate the lithium polysulfides/sulfide binding mechanism with functional groups. The carboxyl groups exhibited a strong ability to dissolve the low-order polysulfides via proton transfer, although this type of group is highly unstable. In comparison, 1,2-diaminopropane with adjacent amino groups can strongly anchor the high-order polysulfides. The electrostatic attractions between lithium-ion and the electron-rich groups and their number and location dominated the binding energetics. Also, the entropy contribution to the binding should be considered. The information gained from these results can serve as a criterion for the selection of co-solvent for the electrolyte or postmodified functional groups for decorating the cathode in the lithium-sulfur system.

Listeriosis Cases and Genetic Diversity of Their L. monocytogenes Isolates in China, 2008-2019.

Listeriosis, caused by Listeria monocytogenes, is a severe food-borne infection. The nationwide surveillance in China concerning listeriosis is urgently needed. In the present study, 144 L. monocytogenes isolates were collected from the samples of blood, cerebrospinal fluid (CSF), and fetal membrane/placenta in China for 12 years from 2008 to 2019. We summarized these listeriosis patients' demographical and clinical features and outcomes. The susceptibility profile for 12 antibiotics was also determined by the broth microdilution method. Multilocus sequence typing (MLST) and serogroups of these listeria isolates were analyzed to designate epidemiological types. We enrolled 144 cases from 29 healthcare centers, including 96 maternal-neonatal infections, 33 cases of bacteremia, 13 cases of neurolisteriosis, and two cutaneous listeriosis. There were 31 (59.6%) fetal loss in 52 pregnant women and four (9.8%) neonatal death in 41 newborns. Among the 48 nonmaternal-neonatal cases, 12.5% (6/48) died, 41.7% (20/48) were female, and 64.6% (31/48) occurred in those with significant comorbidities. By MLST, the strains were distinguished into 23 individual sequence types (STs). The most prevalent ST was ST87 (49 isolates, 34.0%), followed by ST1 (18, 12.5%), ST8 (10, 6.9%), ST619 (9, 6.3%), ST7 (7, 4.9%) and ST3 (7, 4.9%). Furthermore, all L. monocytogenes isolates were uniformly susceptible to penicillin, ampicillin, and meropenem. In summary, our study highlights a high genotypic diversity of L. monocytogenes strains causing clinical listeriosis in China. Furthermore, a high prevalence of ST87 and ST1 in the listeriosis should be noted.

Characterization of the complete chloroplast genome of medical plant Curculigo orchioides Gaertn. (Amaryllidaceae).

Curculigo orchioides Gaertn. distributed in subtropical regions of Asia including southern China and India. The plant is used as a traditional medicine in China for the treatment of menorrhagia, osteoporosis, and other gynecological problems. The complete chloroplast genome was reported in this study using the Illumina NovaSeq platform. The whole genome of this species was 157,472 bp in length, with a total GC content of 37.44%. The large single copy (LSC) was 86,507 bp, the small single copy (SSC) was 16,867 bp, and both of the two inverted repeats (IRs) were 27,049 bp, respectively. A total of 132 unique genes were identified, among which are 86 protein-coding genes, 38 tRNA genes and 8 rRNA genes. The phylogenetic analysis revealed that C. orchioides was highly clustered with C. capitulata. Our study will provide useful fundamental data for further phylogenetic and evolutionary studies of C. orchioides.

The complete chloroplast genome sequence of Ficus altissima (Moraceae).

Ficus altissima plays an important role on biodiversity in tropical forests. In this study, the complete chloroplast genome sequence and the genome features of F. altissima were analyzed using the Illumina NovaSeq platform. The whole chloroplast genome sequence of F. altissima is 160,251 including a large single-copy region (LSC, 88,468 bp), a small single-copy region (SSC, 20,009 bp), and a pair of repeat regions (IRs, 25,887 bp, each). Further gene annotation revealed the chloroplast genome contains 124 genes, including 79 protein-coding genes, 37 tRNA genes, and 8 rRNA genes. A total of 82 simple sequence repeats (SSRs) were identified in the chloroplast genome. Phylogenetic development was analyzed based on F. altissima with other species of Moraceae. This information will be useful for study on the evolution and genetic diversity of F. altissima in the future.

Human antigen R (HuR) and Cold inducible RNA-binding protein (CIRP) influence intestinal mucosal barrier function in ulcerative colitis by competitive regulation on Claudin1.

To investigate the effects of RNA-binding proteins cold-inducible RNA binding protein (CIRP) and human antigen R (HuR) on expression of Claudin1 and mucosal barrier function in ulcerative colitis (UC). The clinical specimens of UC patients and healthy volunteers were collected. In the clinical experiments, the expressions of CIRP, Claudin1, and HuR, along with their correlations in tissues of UC patients were analyzed by qRT-PCR, Western blot and Pearson correlation coefficient, respectively. The chi-square test was utilized to assess the relevance between CIRP/HuR/Claudin1 level and clinicopathological characteristics of UC patients. The in vitro and in vivo models of UC were established by lipopolysaccharide treatment or dextran sulfate sodium injection. For cell experiments, after loss- and gain-of-function, the roles of CIRP or HuR in the apoptosis and proliferation of enterocytes were examined by flow cytometry and CCK-8 assay. The intestinal epithelial barrier function was inspected after determination on transepithelial electrical resistance value, horseradish peroxidase permeability and expressions of tight junction proteins (Occludin, ZO-1, and JAM-1). The relationship between HuR, CIRP, and Claudin1 was performed by RNA immunoprecipitation and dual-luciferase reporter gene assay. For in vivo experiments, the disease activity index score, weight loss and colon length of mice were assessed to observe the effect of CIRP or HuR on the UC mouse models. Histological analysis of colon tissues was conducted by H&E staining. FITC-dextran tracking was applied to inspect the intestinal mucosal barrier function of UC mouse models. In this study, high expression of CIRP and low expressions of HuR and Claudin1 were observed in patients, cells and mouse models of UC. The expressions of CIRP, HuR, and Claudin1 were correlated with the severity of patients with UC. There was a negative correlation between CIRP and Claudin1, and as a positive correlation between HuR and Claudin1. Claudin1 can be suppressed by CIRP, while enhanced by HuR. HuR and CIRP can competitively bind to Claudin1. HuR upregulation or CIRP downregulation promoted proliferation, suppressed apoptosis and ameliorated the damage of the barrier function in enterocytes. The in vivo experiments verified that the ameliorated damage of the intestinal mucosal barrier function in UC mice occurred with HuR overexpression or CIRP knockdown. CIRP and HuR confer pivotal effect on the intestinal mucosal barrier function of UC through competitively binding to Claudin1 mRNA.

LncRNA TUG1 regulates the balance of HuR and miR-29b-3p and inhibits intestinal epithelial cell apoptosis in a mouse model of ulcerative colitis.

This study aimed to investigate the role of long non-coding RNA (lncRNA) taurine up-regulated 1 (TUG1) in the development of ulcerative colitis (UC) and to explore the underlying mechanisms. A murine model of UC was induced by dextran sodium sulfate (DSS) exposure. The colonic epithelial YAMC cells were treated with TNF-α to simulate the inflammatory environment of intestinal epithelial cells (IECs). RNA pull-down and RIP assays were performed to analyze the interaction between TUG1 and HuR. Luciferase activity assay was conducted to evaluate the interaction between TUG1 and miR-29b-3p. Cell proliferation was evaluated by MTT assay. Cell apoptosis was assessed by flow cytometry and western blot analysis of apoptosis-related proteins. TUG1 overexpression promoted cell proliferation and inhibited cell apoptosis in the TNF-α-stimulated YAMC cells. The mechanistic analysis showed that TUG1 positively regulated the HuR/c-myc axis via its interaction with HuR, leading to upregulation of c-myc expression; meanwhile, TUG1 negatively regulated the miR-29b-3p/CDK2 signaling via binding to miR-29b-3p, leading to derepression of CDK2 expression. Further animal experiments showed that TUG1 overexpression attenuated UC progression in the DSS-induced UC in mice. Collectively, TUG1 inhibits IEC apoptosis and UC progression by regulating the balance of HuR and miR-29b-3p.

Microbiological profiles and antimicrobial resistance patterns of pediatric bloodstream pathogens in China, 2016-2018.

OBJECTIVES: This study aimed to investigate the microbiological profiles and antimicrobial resistance patterns of bloodstream pathogens in Chinese children. METHODS: This retrospective study was conducted at 13 tertiary hospitals in China during 2016-2018. The first bloodstream isolates of the same species from one pediatric patient < 18 years were included to this study for analysis. Antimicrobial susceptibility testing was determined based on minimum inhibitory concentrations or Kirby-Bauer disk diffusion methods according to the 2018 Clinical and Laboratory Standards Institute guidelines. RESULTS: Overall, 9345 nonduplicate bloodstream isolates were collected. Top 10 pathogens included Coagulase-negative staphylococcus (CoNS) (44.4%), Escherichia coli (10.2%), Klebsiella pneumoniae (5.9%), Staphylococcus aureus (5.0%), Streptococcus pneumoniae (4.9%), Pseudomonas aeruginosa(2.8%), Enterococcus faecium (2.7%), Stenotrophomonas maltophilia (2.4%), Salmonella spp. (2.3%), and Streptococcus agalactiae (2.0%). The commonest pathogens apart from CoNS in age group 0-28 days, 29 days-2 months, 3-11 months, 1-5 years, and ≥ 5 years were Escherichia coli (17.2%), Escherichia coli (14.0%), Escherichia coli (7.9%), Streptococcus pneumoniae (10.7%) ,and Staphylococcus aureus (13.6%), respectively. The overall prevalence of extended-spectrum ß-lactamases-producing Enterobacteriaceae, carbapenem-resistant Klebsiella pneumoniae, carbapenem-resistant Acinetobacter baumannii, and carbapenem-resistant Pseudomonas aeruginosa were 41.4, 28.4, 31.7, and 5.6%, respectively. The overall prevalence of methicillin-resistant Staphylococcus aureus, penicillin-resistant Streptococcus pneumoniae and vancomycin-resistant Enterococcus was 38.1, 28.3, and 0.7%, respectively. CONCLUSIONS: The major bacterial pathogens have differences in different age groups, ward types, and regions in Chinese children, and the commonest causing microorganism was the Escherichia coli, especially in neonates and infants. High prevalence of important resistant phenotypes is of a serious concern.

Clinical and Molecular Epidemiologic Characteristics of Ceftazidime/Avibactam-Resistant Carbapenem-Resistant Klebsiella pneumoniae in a Neonatal Intensive Care Unit in China.

BACKGROUND: Ceftazidime/avibactam (CZA)-resistant carbapenem-resistant Klebsiella pneumoniae (CRKP) infections occur in adults worldwide but are rarely observed in neonates. We evaluated the activities of CZA against CRKP and described the clinical and molecular epidemiology of CZA-resistant CRKP in a NICU prior to CZA approval in China. METHODS: A laboratory-based surveillance of CRKP was conducted from July 2017 to June 2018. Clinical data were initially reviewed. Antimicrobial susceptibility was determined by the broth microdilution method. CZA-resistant CRKP isolates were submitted to carbapenemase types screening and multilocus sequence typing. RESULTS: Over 23.3% (10/43) of CRKP strains were resistant to CZA, MIC50 and MIC90 values being 0.5 µg/mL and >32µg/mL, respectively. Most neonates shared similar clinical features with cesarean (n=8), preterm birth (n=6), low birth weight (n=5), and exposure to carbapenems/ß-lactam (n=8). All CZA-resistant CRKP isolates were highly resistant to most tested drugs except for polymyxin B (POL) and tigecycline (TGC). CZA-resistant CRKP isolates showed greater sensitivity to amikacin (AMK), nitrofurantoin (NIT), levofloxacin (LVX) and ciprofloxacin (CIP), compared with CZA-sensitive CRKP. All CZA-resistant CRKP isolates harbored carbapenemase genes, blakpc-2 (n=5) being predominant, followed by blaNDM-1 (n=4) and blaNDM-5 (n=2). Among these CZA-resistant CRKP isolates, a total of eight different STs were identified. CRKP harboring KPC belonged to ST1419, ST37 and ST11, while NDM types were assigned to ST784, ST1710, ST37 and ST324. Furthermore, other ß-lactamase genes including blaSHV and blaCTX-M were also found. CONCLUSION: Over 23.3% of CRKP strains isolated from neonates were resistant to CZA. Cesarean, preterm birth, low birth weight, and exposure to carbapenems/ß-lactam were similar clinical features of most neonates with CZA-resistant CRKP. The predominant carbapenemases of CZA-resistant CRKP were KPC-2 and NDM-1, and KPC-2 producing K. pneumoniae assigned into 3 STs, which indicate the genetic diversity of clinical CZA-resistant CRKP isolates.

Silencing of RHEB inhibits cell proliferation and promotes apoptosis in colorectal cancer cells via inhibition of the mTOR signaling pathway.

Colorectal cancer (CRC) is commonly known as one of the most prominent reasons for cancer-related death in China. Ras homolog enriched in brain (RHEB) and the mammalian target activity of rapamycin (mTOR) signaling pathway were found correlated with CRC, but their specific interaction in CRC was still to be investigated. Therefore, we explored whether RHEB gene silencing affected the cell proliferation, differentiation, and apoptosis by directly targeting the mTOR signaling pathway in cells previously harvested from CRC patients. A microarray analysis was subsequently conducted to investigate the relationship between RHEB and mTOR. Eighty-three adjacent normal tissues and CRC tissues were selected. Immunohistochemistry was carried out to detect the positive expression rates of RHEB and Ki-67 in the CRC tissues. Cells were then transfected with different siRNAs to investigate the potential effects RHEB would have on CRC progression. The expressions of RHEB, 4EBP1, ribosomal protein S6 kinase (p70S6K), proliferating cell nuclear antigen (PCNA), B cell lymphoma 2 (bcl-2), and bcl-2-associated X protein (bax) were determined and then the cell cycle, cell proliferation, and apoptotic rate were also measured. We identified RHEB and mTOR as upregulated genes in CRC. Cells treated with RHEB silencing showed a decreased extent of mTOR, p70S6K, 4EBP1 phosphorylation and expression of RHEB, Ki-67, mTOR, p70S6K, 4EBP1, bcl-2, and PCNA as well as decreased activity of cell proliferation and differentiation; although, the expression of bax was evidently higher. Collectively, our data propose the idea that RHEB gene silencing might repress cell proliferation and differentiation while accelerating apoptosis via inactivating the mTOR signaling pathway.

Downregulation of Proline Hydroxylase 2 and Upregulation of Hypoxia-Inducible Factor 1α are Associated with Endometrial Cancer Aggressiveness.

INTRODUCTION: Proline hydroxylase 2 (PHD2) is involved in tumorigenesis. This study aimed to examine PHD2 and hypoxia-inducible factor 1α (HIF-1α) expression in different endometrial tissues and explore the correlations between PHD2 and HIF-1α expression with clinicopathological characteristics of endometrial cancer. METHODS: We collected 50 tissue sections of endometrial adenocarcinoma, 30 of atypical endometrial hyperplasia, and 30 of control normal endometrium. The expression of PHD2 was detected by PCR, Western blot, and immunohistochemical analysis. RESULTS: PHD2 mRNA and protein levels reduced in endometrial cancer tissues compared to normal endometrium (p<0.05). In contrast, HIF-1α expression levels increased in endometrial cancer tissues compared to normal endometrium (p<0.05). In addition, PHD2 and HIF-1α levels were correlated with lymphovascular stromal invasion (LVSI), postoperative FIGO stage, and lymph node metastasis of endometrial cancer (p<0.05). CONCLUSION: Our findings suggest that reduced expression of PHD2 and increased expression of HIF-1α are associated with endometrial cancer aggressiveness. PHD2 might be a novel biomarker and a potential target for endometrial cancer management.

Microbiological and clinical characteristics of Streptococcus gallolyticus subsp. pasteurianus infection in China.

BACKGROUND: Infections by Streptococcus gallolyticus subsp. pasteurianus (SGSP) is often underestimated. Herein, the epidemiological features and resistant characteristics of SGSP in mainland China are characterized to enable a better understanding of its role in clinical infections. METHODS: In the present work, 45 SGSP isolates were collected from the samples of bloodstream, urine, aseptic body fluid, and fetal membrane/placenta from patients in 8 tertiary general hospitals of 6 cities/provinces in China from 2011 to 2017. The identification of all isolates was performed using traditional biochemical methods, 16S rRNA and gyrB sequencing, followed by the characterization of their antibiotic resistance profiling and involved genes. RESULTS: Among 34 non-pregnancy-related patients, 4 (4/34,11.8%) patients had gastrointestinal cancer, 10 (10/34, 29.4%) patients had diabetes, and one patient had infective endocarditis. Moreover, 11 cases of pregnant women were associated with intrauterine infection (9/11, 81.2%) and urinary tract infection (1/11, 9.1%), respectively. Except one, all other SGSP isolates were correctly identified by the BD Phoenix automated system. We found that all SGSP isolates were phenotypically susceptible to penicillin, ampicillin, cefotaxime, meropenem, and vancomycin. Forty strains (40/45, 88.9%) were both erythromycin and clindamycin-resistant, belonging to the cMLSB phenotype, and the majority of them carried erm(B) gene (39/40, 97.5%). Although the cMLSB/erm(B) constituted the most frequently identified phenotype/genotype combination (25/40, 62.5%) among all erythromycin-resistant cMLSB isolates, erm(B)/erm(A), erm(B)/mef(A/E), and erm(B)/erm(T) was detected in 7, 4, and 3 isolates, respectively. Furthermore, 43 strains (43/45, 95.6%) were tetracycline-resistant, and out of these, 39 strains (39/45, 86.7%) carried tet(L), 27(27/45, 60.0%) strains carried tet(O), and 7 (7/45, 15.6%) strains carried tet(M), alone or combined, respectively. All erythromycin-resistant isolates were also resistant to tetracycline. CONCLUSIONS: It is important to study and draw attention on SGSP, an underreported opportunistic pathogen targeting immunodeficient populations, notably elderly subjects, pregnant women and neonates.