Antimicrobial resistance and plasmid-mediated colistin resistance mechanism of diarrheagenic Escherichia coli recovered from foods in parts of China in 2020 / 中华预防医学杂志

Objective: To investigate the antimicrobial resistance of food-borne diarrheagenic Escherichia coli (DEC) and the prevalence of mcr genes that mediates mobile colistin resistance in parts of China, 2020. Methods: For 91 DEC isolates recovered from food sources collected from Fujian province, Hebei province, Inner Mongolia Autonomous Region and Shanghai city in 2020, Vitek2 Compact biochemical identification and antimicrobial susceptibility testing platform was used for the detection of antimicrobial susceptibility testing (AST) against to 18 kinds of antimicrobial compounds belonging to 9 categories, and multi-polymerase chain reaction (mPCR) was used to detect the mcr-1-mcr-9 genes, then a further AST, whole genome sequencing (WGS) and bioinformatics analysis were platformed for these DEC isolates which were PCR positive for mcr genes. Results: Seventy in 91 isolates showed different antimicrobial resistance levels to the drugs tested with a resistance rate of 76.92%. The isolates showed the highest antimicrobial resistance rates to ampicillin (69.23%, 63/91) and trimethoprim-sulfamethoxazole (59.34%, 54/91), respectively. The multiple drug-resistant rate was 47.25% (43/91). Two mcr-1 gene and ESBL (extended-spectrum beta-lactamase) positive EAEC (enteroaggregative Escherichia coli) strains were detected. One of them was identified as serotype of O11:H6, which showed a resistance profile to 25 tested drugs referring to 10 classes, and 38 drug resistance genes were predicted by genome analysis. The other one was O16:H48 serotype, which was resistant to 21 tested drugs belonging to 7 classes and carried a new variant of mcr-1 gene (mcr-1.35). Conclusion: An overall high-level antimicrobial resistance was found among foodborne DEC isolates recovered from parts of China in 2020, and so was the MDR (multi-drug resistance) condition. MDR strains carrying multiple resistance genes such as mcr-1 gene were detected, and a new variant of mcr-1 gene was also found. It is necessary to continue with a dynamic monitoring on DEC contamination and an ongoing research into antimicrobial resistance mechanisms.

Mechanism of Marsdenia tenacissima against ovarian cancer based on network pharmacology and experimental verification / 中国中药杂志

The present study aimed to explore the main active components and underlying mechanisms of Marsdenia tenacissima in the treatment of ovarian cancer(OC) through network pharmacology, molecular docking, and in vitro cell experiments. The active components of M. tenacissima were obtained from the literature search, and their potential targets were obtained from SwissTargetPrediction. The OC-related targets were retrieved from Therapeutic Target Database(TTD), Online Mendelian Inheritance in Man(OMIM), GeneCards, and PharmGKB. The common targets of the drug and the disease were screened out by Venn diagram. Cytoscape was used to construct an "active component-target-disease" network, and the core components were screened out according to the node degree. The protein-protein interaction(PPI) network of the common targets was constructed by STRING and Cytoscape, and the core targets were screened out according to the node degree. GO and KEGG enrichment analyses of potential therapeutic targets were carried out with DAVID database. Molecular docking was used to determine the binding activity of some active components to key targets by AutoDock. Finally, the anti-OC activity of M. tenacissima extract was verified based on SKOV3 cells in vitro. The PI3K/AKT signaling pathway was selected for in vitro experimental verification according to the results of GO function and KEGG pathway analyses. Network pharmacology results showed that 39 active components, such as kaempferol, 11α-O-benzoyl-12β-O-acetyltenacigenin B, and drevogenin Q, were screened out, involving 25 core targets such as AKT1, VEGFA, and EGFR, and the PI3K-AKT signaling pathway was the main pathway of target protein enrichment. The results of molecular docking also showed that the top ten core components showed good binding affinity to the top ten core targets. The results of in vitro experiments showed that M. tenacissima extract could significantly inhibit the proliferation of OC cells, induce apoptosis of OC cells through the mitochondrial pathway, and down-regulate the expression of proteins related to the PI3K/AKT signaling pathway. This study shows that M. tenacissima has the characteristics of multi-component, multi-target, and multi-pathway synergistic effect in the treatment of OC, which provides a theoretical basis for in-depth research on the material basis, mechanism, and clinical application.

Efficacy and Mechanism of Yishen Shengjing Prescription in Treatment of Oligoasthenospermia / 中国实验方剂学杂志

ObjectiveWe aimed to investigate the efficacy and mechanism of Yishen Shengjing Prescription （YSP） in the treatment of oligoasthenospermia in rats. MethodThe oligoasthenospermia rat model was established by injection with cyclophosphamide （35 mg·kg-1·d-1） for 5 consecutive days. Rats were randomly assigned into control group （without treating with cyclophosphamide）， model group， low- （YSP-L）， medium- （YSP-M）， and high- （YSP-H） dose （2.91， 5.83， and 11.66 g·kg-1， respectively） groups， Wuzi Yanzongwan （WYW， 1.03 g·kg-1） group， and L-carnitine （0.17 g·kg-1） group， with 8 rats in each group. After 28 days of drug intervention， the body weight， testicular weight， and testicular index of rats were recorded. The sperm quality in epididymis was detected by computer-assisted sperm analysis （CASA） system. Hematoxylin-eosin （HE） staining was employed for observation of testicular tissue morphology. The levels of malondialdehyde （MDA） and superoxide dismutase （SOD） in testicular tissue were detected by colorimetry. The levels of follicle-stimulating hormone （FSH）， luteinizing hormone （LH）， and testosterone （T） in serum were determined by enzyme-linked immunosorbent assay（ELISA）. TdT-mediated dUTP nick-end labeling （TUNEL） was employed to detect the apoptosis of testicular cells. The protein levels of B cell lymphoma-2（Bcl-2）， Bax， and cleaved Caspase-3 in testicular tissue were detected by Western blot. ResultCompared with the control group， the model group showed decreased body weight， testicular weight and index， sperm concentration and motility （P<0.01） and increased testicular pathological score （P<0.01）. Compared with the model group， the YSP-M， YSP-H， WYW， and L-carnitine groups showed increased body weight， testicular weight， testicular index， sperm concentration and motility and decreased testicular pathological score. After modeling， the SOD level decreased （P<0.01） while the MDA content increased （P<0.01） in the testicular tissue. YSP-H， WYW， and L-carnitine reversed the SOD and MDA level changes caused by modeling. Compared with the control group， the model group exhibited declined T level （P<0.01） and increased FSH and LH levels （P<0.01）. Compared with the model group， YSP， WYW， and L-carnitine increased the T level （P<0.01） and decreased the LH level （P<0.05， P<0.01）. The apoptosis rate of spermatogenic cells in the model group was higher than that in the control group （P<0.01）， whereas YSP-M， WYW， and L-carnitine reversed such changes （P<0.01）. The model group rats showed decreased expression of Bcl-2（P<0.05） and increased expression of Bax and cleaved Caspase-3 （P<0.05， P<0.01）. Compared the model group， YSP-M， YSP-H， WYW， and L-carnitine up-regulated the Bcl-2 expression and down-regulated the cleaved Caspase-3 expression （P<0.05， P<0.01）. ConclusionYSP improved the sperm quality of oligoasthenospermia model rats by regulating the antioxidant system and sex hormone levels and inhibiting the apoptosis of spermatogenic cells.

Research Status on Animal Models for Melasma / 中国实验方剂学杂志

Melasma， as a kind of melanosis， often occurs over the face of young and middle-aged women， which seriously affects the physical and mental health of patients. At present， it is believed that the occurrence of melasma is related to various factors such as ultraviolet radiation and changes in sex hormone levels in the body. However， the exact pathogenesis of melasma is still unclear and its clinical efficacy is not ideal. Therefore， it is of great clinical significance and social value to carry out basic researches on melasma diseases. Among them， the animal model of melasma acts as an important tool for studying melasma， and it is particularly important to clarify the pathophysiological mechanism of the occurrence and development of melasma. The common modeling methods include ultraviolet modeling， progesterone modeling and ultraviolet combined with progesterone modeling. However， there are still some problems in the practical application of animal models of melasma due to many influencing factors in the preparation of such animal models， and there is still a lack of a more complete and recognized model preparation scheme to this day， which reduces the success rate of model preparation and limits its application and popularization to some extent. In view of the key problems in the establishment and application of animal models of melasma， we comprehensively summarized the research status of the models from such aspects as experimental animals， modeling methods and model evaluation， and discussed the effects of different modeling methods and animal species， animal age and other factors on animal model of melasma by referring to and sorting out the recent literatures at home and abroad in recent years. This is to provide references for the preparation of more scientific， reasonable， economic and convenient animal models of melasma， lay a foundation for in-depth researches on the pathogenesis， prevention and treatment of melasma， and also provide reference for other animal model research.

Family with Sequence Similarity 83 Member H Promotes the Viability and Metastasis of Cervical Cancer Cells and Indicates a Poor Prognosis

PURPOSE: Family with sequence similarity 83 member H (FAM83H) plays key roles in tumorigenesis. However, the specific roles of FAM83H in cervical cancer (CC) have not been well studied. MATERIALS AND METHODS: The RNA-seq data of 306 CC tissues and three normal samples downloaded from The Cancer Genome Atlas were used to analyze the expression of FAM83H. The Kaplan-Meier method was used to draw survival curves. Associations between FAM83H expression and clinicopathological factors were analyzed by chi-square test. Cox proportional hazards model was used to analyze prognostic factors. Loss-of-function assays were conducted to discover the biological functions of FAM83H in cell proliferation, colony formation, invasion, and migration. Real-time Quantitative Reverse Transcription PCR (qRT-PCR) and Western blotting were used to measure the expression levels of FAM83H in CC cell lines. RESULTS: Our results demonstrated that FAM83H is overexpressed in CC tissues and that high FAM83H expression is associated with worse overall survival (OS). High FAM83H expression in CC was associated with clinical stage, pathologic tumor, and pathologic node. Univariate analysis suggested that FAM83H expression was significantly related to the OS of CC patients. Although multivariate analysis showed that FAM83H expression was not an independent prognostic factor for the OS of CC patients, the effects of FAM83H on CC cell growth and motility was significant. Loss-of-function experiments demonstrated that knockdown of FAM83H inhibited proliferation, colony formation, migration, and invasion of CC cells by inactivating PI3K/AKT pathway. CONCLUSION: FAM83H might play a crucial role in CC progression and could act as a novel therapeutic target in CC.

Genotypic Characterization of Methicillin-resistant Staphylococcus aureus Isolated from Pigs and Retail Foods in China / 生物医学与环境科学（英文）

<p><b>OBJECTIVE</b>To investigate the genotypic diversity of Methicillin-resistant Staphylococcus aureus (MRSA) isolated from pigs and retail foods from different geographical areas in China and further to study the routes and rates of transmission of this pathogen from animals to food.</p><p><b>METHODS</b>Seventy-one MRSA isolates were obtained from pigs and retail foods and then characterized by multi-locus sequencing typing (MLST), spa typing, multiple-locus variable number of tandem repeat analysis (MLVA), pulsed-field gel electrophoresis (PFGE), and antimicrobial susceptibility testing.</p><p><b>RESULTS</b>All isolated MRSA exhibited multi-drug resistance (MDR). Greater diversity was found in food-associated MRSA (7 STs, 8 spa types, and 10 MLVA patterns) compared to pig-associated MRSA (3 STs, 1 spa type, and 6 MLVA patterns). PFGE patterns were more diverse for pig-associated MRSA than those of food-associated isolates (40 vs. 11 pulse types). Among the pig-associated isolates, CC9-ST9-t899-MC2236 was the most prevalent clone (96.4%), and CC9-ST9-t437-MC621 (20.0%) was the predominant clone among the food-associated isolates. The CC9-ST9 isolates showed significantly higher antimicrobial resistance than other clones. Interestingly, CC398-ST398-t034 clone was identified from both pig- and food-associated isolates. Of note, some community- and hospital-associated MRSA strains (t030, t172, t1244, and t4549) were also identified as food-associated isolates.</p><p><b>CONCLUSION</b>CC9-ST9-t899-MC2236-MDR was the most predominant clone in pigs, but significant genetic diversity was observed in food-associated MRSA. Our results demonstrate the great need for improved surveillance of MRSA in livestock and food and effective prevention strategies to limit MDR-MRSA infections in China.</p>

Antimicrobial Resistance, Virulence Profile, and Molecular Characterization of Listeria monocytogenes Isolated from Ready-to-eat Food in China, 2013-2014 / 生物医学与环境科学（英文）

We aimed to investigate the potential pathogenic profile and antibiotic resistance of Listeria monocytogenes isolated from ready-to-eat food in China. Antimicrobial resistance was determined by broth microdilution following the Clinical and Laboratory Standards Institute protocol. Molecular serotyping, virulence, and resistance genes were identified using PCR. Multi-locus sequence typing was performed on resistant strains. A total of 11.53% (113/980) isolates were resistant, from which 82.3% (93/113) harbored all the virulence genes tested. The resistant strains were subtyped into 18 sequence types (STs), from which ST2, ST5, ST8, and ST9 were involved in listeriosis. This study indicated that several L. monocytogenes isolates from ready-to-eat foods in China have pathogenic potential and are resistant to antibiotics, including antibiotics used as medicines by humans for listeriosis treatment.