Outbreak of OXA-232-producing carbapenem-resistant Klebsiella pneumoniae ST15 in a Chinese teaching hospital: a molecular epidemiological study.

Background and Aims: The incidence of OXA-232-producing carbapenem-resistant Klebsiella pneumoniae (CRKP) has been on the rise in China over the past five years, potentially leading to nosocomial epidemics. This study investigates the first outbreak of CRKP in the Second Affiliated Hospital of Jiaxing University. Methods: Between February 2021 and March 2022, 21 clinical isolates of OXA-232-producing CRKP were recovered from 16 patients in the Second Affiliated Hospital of Jiaxing University. We conducted antimicrobial susceptibility tests, whole genome sequencing, and bioinformatics to determine the drug resistance profile of these clinical isolates. Results: Whole-genome sequencing revealed that all 21 OXA-232-producing CRKP strains belonged to the sequence type 15 (ST15) and shared similar resistance, virulence genes, and plasmid types, suggesting clonal transmission between the environment and patients. Integrated genomic and epidemiological analysis traced the outbreak to two clonal transmission clusters, cluster 1 and cluster 2, including 14 and 2 patients. It was speculated that the CRKP transmission mainly occurred in the ICU, followed by brain surgery, neurosurgery, and rehabilitation department. Phylogenetic analysis indicated that the earliest outbreak might have started at least a year before the admission of the index patient, and these strains were closely related to those previously isolated from two major adjacent cities, Shanghai and Hangzhou. Comparative genomics showed that the IncFII-type and IncHI1B-type plasmids of cluster 2 had homologous recombination at the insertion sequence sites compared with the same type of plasmids in cluster 1, resulting in the insertion of 4 new drug resistance genes, including TEM-1, APH(6)-Id, APH(3'')-Ib and sul2. Conclusions: Our study observed the clonal spread of ST15 OXA-232-producing between patients and the hospital environment. The integration of genomic and epidemiological data offers valuable insights and facilitate the control of nosocomial transmission.

Protective Effects of MitoTEMPO on Nonalcoholic Fatty Liver Disease via Regulating Myeloid-Derived Suppressor Cells and Inflammation in Mice.

MitoTEMPO, a mitochondrial antioxidant, has protective effects on liver-related diseases. However, the role of MitoTEMPO on nonalcoholic fatty liver disease (NAFLD) and its possible mechanisms are largely unknown. Here, we investigated the effects of MitoTEMPO on NAFLD using high fat diet- (HFD-) induced obese mice as animal models. MitoTEMPO was intraperitoneally injected into HFD mice. Liver morphological changes were observed by H&E and Oil Red O staining, and the frequency of MDSCs in peripheral blood was analyzed by flow cytometry. Moreover, real-time quantitative PCR, western blot, and immunohistochemistry were conducted to detect the mRNA and protein expressions in the liver tissues. The results showed that the hepatic steatosis in liver tissues of HFD mice injected with MitoTEMPO was significantly ameliorated. Additionally, MitoTEMPO reduced the frequency of CD11b+Gr-1+ MDSCs in peripheral circulation and decreased Gr-1+ cell accumulation in the livers. Further studies demonstrated that MitoTEMPO administration suppressed the mRNA and protein expressions of MDSC-associated proinflammatory mediators, such as monocyte chemoattractant protein-1 (MCP-1), S100 calcium-binding protein A8 (S100A8), and S100 calcium-binding protein A9 (S100A9). Our results suggest that MitoTEMPO appears to be a potential chemical compound affecting certain immune cells and further ameliorates inflammation in obese-associated NAFLD.

Effect of aberrantly methylated androgen receptor target gene PCDH7 on the development of androgen-independent prostate cancer cells.

BACKGROUND: Androgen-independent prostate cancer (AIPC) is an extremely malignant tumor developed from the androgen dependent (ADPC). However, the mechanism of transition process from ADPC to AIPC remains unknown. OBJECTIVE: Here we aimed to identify the androgen receptor (AR) target gene and its roles in AIPC. METHODS: Target genes of AR were identified by ChIP-seq in AIPC cells. AR target gene PCDH7 was detected by real time PCR and western blot. Methylation of PCDH7 was measured by bisulfite sequencing and bisulfite amplicon sequencing. Cell growth, invasion and apoptosis were measured by CCK-8, transwell and flow cytometry, respectively. RESULTS: AR was significantly enriched in the upstream of PCDH7 gene. The expression of PCDH7 was significantly decreased, while the methylation of PCDH7 was increased in the AIPC cells compared to the ADPC cells. DNA methyltransferase inhibitor significantly suppressed the methylation and increased the mRNA and protein level of PCDH7. Moreover, overexpression of DNMT1 remarkably reduced the mRNA and protein level of PCDH7. DNA methyltransferase inhibitor decreased the cell growth and invasion while promote the cell apoptosis in the AIPC cells. AR significantly target PCDH7, whose hypermethylation may repress cell growth and invasion, and promote apoptosis in AIPC. CONCLUSIONS: This study might provide a novel potential target for the treatment of AIPC.

[Determination of purity and impurities of ethylene glycol for industrial use by gas chromatography].

A new test method was established for the determination of purity and impurities of ethylene glycol (EG) by gas chromatography (GC) using a Rtx-624 column (30 m×0.32 mm×1.8 µm). The method determined not only the impurities in EG from the ethylene oxidation process, such as diethylene glycol, triethylene glycol and (1,3-dioxolan-2-yl)methanol, but also the impurities from the oxalate hydrogenation process, such as 1,2-butanediol, 1,4-butanediol, 1,2-hexanediol, and ethylene carbonate, etc. The method showed good repeatability and high detection sensitivity. The lowest LOD of the impurities reached to 0.0002% (mass fraction), and the recoveries of the impurities were in the range of 91.2%-105.4%. The proposed method can be applied in production control, product testing and market trade of ethylene glycol.