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Background: Shewanella genus, as an important carrier of resistance genes, has the potential to transmit resistance to many antimicrobials in many circumstances, especially in aquatic environment. The aim of the study was to describe the risk of Shewanella xiamenensis in hospital environment through analysis of genomic comparison and resistance status. Methods: Seven S. xiamenensis strains were isolated from hospital wastewater. PCR and Sanger sequencing were carried out for detection of common carbapenemase genes. Antimicrobial susceptibility testing was performed to determine the antimicrobial profile. Whole genome sequencing was applied, and sequences were further used for genomic analysis. Results: Seven Shewanella xiamenensis were all positive for blaNDM and blaOXA-48. Antimicrobial susceptibility testing showed all Shewanella xiamenensis were resistant to cefotaxime, ceftazidime, imipenem, meropenem, gentamycin and trimethoprim-sulfamethoxazole. Whole genome sequencing and phylogenetic analysis demonstrated the diversity of Shewanella xiamenensis despite isolating from one wastewater pool. Conclusion: To the best of our knowledge, this is the first report of detection of three types blaOXA-48-like genes in one hospital in China. And we have detected multi-drug resistant S. xiamenensis from hospital wastewater. This emphasizes that the presence of naturally existing carbapenemases in the environment may be significantly overlooked and that the blaOXA-48-like genes in China may originate through the horizontal gene transfer from S. xiamenensis to Enterobacterales rather than import from other countries. [ABSTRACT FROM AUTHOR]

The prevalence of carbapenem-resistant Enterobacteriaceae (CRE) is increasing globally, with different molecular mechanisms described. Here we studied the molecular mechanisms of carbapenem resistance, including clonal and plasmid dissemination, of 67 CRE isolates collected between 2012 and 2016 from a tertiary hospital in Eastern China, an CRE endemic region. Species identification and susceptibility testing were performed using the BD Phoenix Automated Microbiology System. Isolates were characterized by PCR (for carbapenemases, ESBLs, AmpC and porin genes), multilocus sequence typing (MLST), pulsed-field gel electrophoresis (PFGE), and conjugation transfer experiments. Selected bla KPC-2 -harboring plasmids were subjected to next-generation sequencing using the Illumina Miseq platform. Among the 67 CRE isolates, 42 Klebsiella pneumoniae , 10 Serratia marcescens , 6 Enterobacter cloacae , 2 Raoultella ornithinolytica , 2 K. oxytoca , 1 K. aerogenes , and 4 Escherichia coli isolates were identified. Six different carbapenemases were detected, including bla KPC-2 (n = 45), bla KPC-3 (n = 1), bla NDM-1 (n = 6), bla NDM-5 (n = 1), bla IMP-4 (n = 2), and bla VIM-1 (n = 2); bla OXA-48-like genes were not detected. One E. cloacae strain possessed both bla NDM-1 and bla KPC-3, while two E. cloacae isolates harbored bla NDM-1 and bla VIM-1. ESBLs (CTX-M, SHV, and TEM) and/or AmpC (CMY, DHA, and ACT/MIR) genes were also identified in 59 isolates, including 13 strains that lacked carbapenemases. Several insertions or stop codon mutations were found within porin genes of K. pneumoniae, E. coli and S. marcescens isolates, both with and without carbapenemases. The 42 K. pneumoniae isolates belonged to 12 different sequence types (ST), with ST11 being the most common, while the 6 E. cloacae isolates comprised 4 different STs. The 10 S. marcescens all shared the same PFGE pulsotype, suggestive of clonal spread. Complete plasmid sequencing and PCR screening revealed both intra-strain and inter-species spread of a common bla KPC-2-harboring plasmid in our hospital. Taken together, our study revealed extensive genetic diversity among CRE isolates form a single Chinese hospital. CRE isolates circulating in the hospital differ significantly in their species, STs, porin genes, carbapenemase genes, and their plasmid content, highlighting the complex dissemination of CRE in this endemic region. [ABSTRACT FROM AUTHOR]

Patchouli alcohol (PA), a tricyclic sesquiterpene, is one of the critical bioactive ingredients and is mainly isolated from aerial part of Pogostemon cablin (known as guanghuoxiang in China) belonging to Labiatae. So far, PA has been widely applied in perfume industries. This review was written with the use of reliable information published between 1974 and 2016 from libraries and electronic researches including NCKI, PubMed, Reaxys, ACS, ScienceDirect, Springer, and Wiley-Blackwell, aiming at presenting comprehensive outline of security, pharmacokinetics, and bioactivities of PA and at further providing a potential guide in exploring the PA and its use in various medical fields. We found that PA maybe was a low toxic drug that was acquired numerously through vegetable oil isolation and chemical synthesis and its stability and low water dissolution were improved in pharmaceutics. It also possessed specific pharmacokinetic characteristics, such as two-compartment open model, first-order kinetic elimination, and certain biometabolism and biotransformation process, and was shown to have multiple biological activities, that is, immunomodulatory, anti-inflammatory, antioxidative, antitumor, antimicrobial, insecticidal, antiatherogenic, antiemetic, whitening, and sedative activity. However, the systematic evaluations of preparation, pharmaceutics, toxicology, pharmacokinetics, and bioactivities underlying molecular mechanisms of action also required further investigation prior to practices of PA in clinic. [ABSTRACT FROM AUTHOR]

Phyllanthus reticulatus (Euphorbiaceae) is a medicinal plant that has been used in Zhuang medicine since ancient times. Traditionally, it has the effect of removing toxins and detumescence and can be used to treat hepatitis in China and India. Our previous studies have proved that the ethyl acetate extract of its leaves (PRPE) has an anti-hepatoma effect. To predict targets of an ethyl acetate extract of Phyllanthus reticulatus leaves (PRPE) in hepatoma treatment via network pharmacology and verify the predictions in a mouse model of liver cancer. Chemical constituents and therapeutic targets of P. reticulatus (PRP) were searched and predicted via public databases. A protein-protein interaction network comprising common targets was constructed, and the key gene targets were identified. Gene Ontology (GO) and Kyoto Encyclopedia of Genes and Genomes (KEGG) analyses were used for biological function and pathway enrichment analyses. The effects of PRP on BEL-7404 and HepG 2 cells were determined by MTT assay, apoptosis was measured by flow cytometry and hoechst44432/PI. And a nude mouse xenograft model was established to verify the anti-tumour effect in vivo. The histopathology of tumours was observed by staining with haematoxylin and eosin (H&E). Reverse transcription-polymerase chain reaction (RT-PCR) and immunohistochemistry were used to determine the gene and protein expression levels of phosphoinositide 3-kinase (PI3K), Akt1, p53, caspase-3, Bcl-2 and Bax, respectively. Twenty-seven chemical components and 567 potential therapeutic targets of PRP were identified. GO analysis indicated that these targets are mainly associated with peptidyl-tyrosine phosphorylation and steroid metabolic process. KEGG analysis showed that the targets are mainly located in the PI3K/Akt, apoptosis, mitogen-activated protein kinase (MAPK), Ras and vascular endothelial growth factor (VEGF) signalling pathways. According to the p -adjust value, the PI3K/Akt pathway is the core pathway. In vitro, PRPE could inhibit proliferation and induce apoptosis in hepatoma cells. IC 50 values of PRPE were 2.48 and 6.34 mg/mL for BEL-7404 and hepG 2 cells, respectively. PRPE significantly reduced tumour volume and weight. H&E results showed that PRPE repaired necrotic areas in hepatoma cells. PRPE reduced the protein expression of PI3K, Akt1 and Bcl-2 and increased the protein expression of p53 and Bax. Meanwhile, PRPE reduced the mRNA expression of PI3K, AKT1 and BCL 2 and increased the mRNA expression of TP53, CASP3 and BAX. The targets of PRPE are the PI3K/Akt, apoptosis, MAPK, Ras and VEGF signalling pathways. Passing through the PI3K/Akt pathway to induce apoptosis is the main mechanism of PRPE. [Display omitted] • The targets of PRP are mainly located in the PI3K/Akt and apoptosis signalling pathways. • PRPE could induce apoptosis in hepatoma cells. • PRPE reduced the protein expression of PI3K, Akt1 and Bcl-2 and increased the protein expression of p53 and Bax. [ABSTRACT FROM AUTHOR]

Epidemiological characteristics and molecular features of carbapenem-resistant Enterobacter (CR- Ent ) species remain unclear in China. In this study, we performed a genomic study on 92 isolates from Enterobacter -caused infections from a multicenter study in China. Whole genome sequencing (WGS) was used to determine the genome sequence of 92 non-duplicated CR- Ent strains collected from multiple tertiary health centres. The precise species of Enterobacter strains were identified by average nucleotide identity (ANI) and in silico DNA-DNA hybridization (isDDH). Molecular features of high-risk CR- Ent sequence type (ST) lineages and carbapenemase-encoding plasmids were determined. The result revealed that the most common human-source CR- Ent species in China was E. xiangfangensis (66/92, 71.93%), and the proportion of carbapenemase-producing Enterobacter (CP- Ent ) in CR- Ent was high (72/92, 78.26%) in comparison to other global regions. Furthermore, ST171 and ST116 E. xiangfangensis were the major lineages of CP- Ent strains, and ST171 E. xiangfangensis was more likely to cause infections in older patients. Genomic analysis also highlighted the likelihood of intra-hospital/inter-hospital clonal transmission of ST171 and ST116 E. xiangfangensis . In addition, the bla NDM -harbouring IncX3-type plasmid was identified as the prevalent carbapenemase-encoding plasmid carried by CR- Ent in China in the form of multicenter for the first time. The high risk of carbapenemase-producing ST171 and ST116 Ent in China in the form of multicenter for the first time. The high risk of carbapenemase-producing ST171 and ST116 E. xiangfangensis , and the bla NDM -harbouring IncX3-type plasmid were detected and emphasized.

Since the discovery of NDM-1 and the worldwide reporting of different variants have raised alarms concerning global health, the problem of carbapenem-resistant Enterobacterales (CRE) has become increasingly serious. Therefore, research on the hydrolytic activity and molecular structure of NDM variants is beneficial to the development of antibacterial drugs. NDM has been evolving into variants that possess different hydrolysis activities toward β-lactam antibiotics. Here, we characterized a novel bla NDM variant, named bla NDM-33 , identified from a multidrug-resistant Escherichia coli strain from hospital sewage. NDM-33 differed from NDM-5 with a single-amino-acid substitution (A72T). bla NDM-5 was located in the Tn 125 -related bla NDM-33 region from an IncX3-type plasmid, pHD6415-NDM, that can be transferred horizontally. The genetic construct of bla NDM-33 showed higher MICs of carbapenems than a bla NDM-5 construct. Enzyme kinetics showed that NDM-33 had higher enzymatic activity for meropenem and cefazolin than NDM-5. The emergence of this novel NDM variant could pose a threat to public health because of its transferability and enhanced carbapenem activity. IMPORTANCE Our study described a novel NDM-33 variant from an E. coli strain isolated from hospital sewage, where it was associated with human disease and antibiotic exposure. Importantly, hospital sewage was increasingly considered to be related to CRE hosts. Pathogens were transmitted from reservoirs through direct and indirect contact, ingestion, and inhalation of contaminated water or aerosols. In addition, under the selective pressure of antibiotics, NDM variants will become the main strain in the hospital water system and evolve into high virulence and high resistance. The monitoring of NDM mutants is of great significance for preventing and controlling the evolution of superbugs.