Whole genome analysis reveals new insights into the molecular characteristics of Clostridioides difficile NAP1/BI/027/ST1 clinical isolates in the People's Republic of China.

Background: The epidemic new strain NAP1/BI/027/ST-1 of Clostridioides difficile (C. difficile) causes more severe coliti and a higher mortality rate than historical strains. However, C. difficile NAP1/BI/027/ST-1 (C. difficile RT027) infections have been rarely reported in Asia, particularly in China. Purpose: The objective of this study was to strengthen the understanding of the molecular characterizations of C. difficile RT027 in China. Patients and methods: Two C. difficile NAP1/BI/027/ST-1 were detected from two patients, and no additional isolates were found. Whole genome sequencing (WGS) was used to characterize two C. difficile RT027 isolates and control strain CD6 (from Hong Kong), and comparative genomic analysis was performed to compare genomic differences between seven isolates from Mainland China, CD6, and 10 isolates from North America and Europe. Results: The comparative genomic analysis revealed that isolates obtained from Mainlan China were outside of the two epidemic lineages, FQR1 and FQR2, and might have decreased virulence and transmissibility for outbreak. Furthermore, unique SNP mutations were detected in isolates obtained from Mainland China, which may affect the biological function of C. difficile. Conclusion: We speculate that C. difficile RT027 isolates in Mainland China may have different features, compared to those in North America and Europe.

Simultaneous determination of eight components in Angelica sinensis based on UHPLC-ESI-MS/MS method for quality evaluation.

A method employing ultra-high performance liquid chromatography-tandem mass spectrometry (UHPLC-MS/MS) for determination of eight components including ferulic acid, senkyunolide A, butylphthalide, ligustilide, butylidenephalide, senkyunolide I, senkyunolide H and levistolide A in Angelica sinensis was established. The separation was carried out using a Waters ACQUITY UHPLC BEH C18 column with gradient elution with 0.1% formic acid aqueous and acetonitrile at a flow rate of 0.4 mL/min. Good linearity was attained with R2 of 0.9983-0.9998 in wide concentration ranges. The method had limit of detection (LOD) and quantitation (LOQ) in the range of 0.42-6.98 ng/mL and 1.39-23.28 ng/mL, respectively. Intra- and inter-day precisions varied with relative standard deviations (RSDs) from 0.33% to 0.88% and 0.37% to 1.04%, respectively. Moreover, the average recoveries were in a satisfactory range of 92.7%-102.1% with RSDs of less than 3.60%. Finally, the method was successfully applied to analyze 19 batches of A. sinensis samples grown in Min County, Gansu province, China, as well as that collected in other regions. The findings indicated that the established method is reliable and may thus be applied as a powerful tool for qualitative and quantitative analysis of components in A. sinensis, which has its implications in quality control of A. sinensis.

Ureaplasma urealyticum-derived lipid-associated membrane proteins introduce IL-6, IL-8, and TNF-α cytokines into human amniotic epithelial cells via Toll-like receptor 2.

OBJECTIVE: The purpose of this study was to determine the role of Ureaplasma urealyticum-derived lipid-associated membrane proteins (LAMPs) in the host innate immune system, specifically their effect on Toll-like receptors (TLRs). METHODS: LAMPs were derived from U. urealyticum strains, and human amniotic epithelial cells (HAECs) were isolated from healthy full-term placentas. Cytokine concentrations were determined by enzyme-linked immunosorbent assay (ELISA) and TLR2 mRNA by real-time PCR. Expression of TLR2 was confirmed by Western blotting and immunohistochemistry. RESULTS: LAMPs induced HAECs to produce inflammatory cytokines interleukin (IL)-6, IL-8, and tumor necrosis factor (TNF)-α. Cytokine production was reduced after blocking TLR2 using TLR2 inhibitor (anti-hTLR2-IgA). CONCLUSIONS: LAMPs isolated from U. urealyticum induced TLR2-dependent up-regulation of inflammatory genes and cytokines in HAECs.

In vitro activities of tedizolid compared with other antibiotics against Gram-positive pathogens associated with hospital-acquired pneumonia, skin and soft tissue infection and bloodstream infection collected from 26 hospitals in China.

To evaluate the in vitro antimicrobial activities of tedizolid, linezolid and other comparators against clinically significant Gram-positive cocci isolates from hospital-acquired pneumonia (HAP), skin and soft tissue infection (SSTI) and bloodstream infection (BSI), 2140 nonduplicate isolates (23.7 % isolated from HAP, 46.8 % from SSTI and 29.5 % from BSI) were consecutively collected in 26 hospitals in 17 cities across China during 2014. These pathogens included 632 methicillin-resistant Staphylococcus aureus, 867 methicillin-sensitive Staphylococcusaureus, 299 coagulase-negative Staphylococcus (CoNS), 104 Enterococcus faecalis, 99 Enterococcusfaecium, 13 Streptococcus pneumoniae, 23 α-haemolytic Streptococcus and 103 ß-haemolytic Streptococcus. MICs of routine clinical antibiotics were determined by broth microdilution method according to the Clinical and Laboratory Standards Institute guidelines 2015. Tedizolid, linezolid, vancomycin, daptomycin, teicoplanin and tigecycline showed high in vitro activity against Gram-positive pathogens (≥98.0 % susceptible), and tedizolid exhibited four- to eight fold greater activity than linezolid against the pathogens tested, with MIC90s of methicillin-resistant Staphylococcus aureus, α-haemolytic Streptococcus and ß-haemolytic Streptococcus (0.25 vs 2 µg ml-1); methicillin-sensitive Staphylococcu saureus, E. faecalis and E. faecium (0.5 vs 2 µg ml-1); methicillin-resistant CoNS and methicillin-sensitive CoNS (0.25 vs 1 µg ml-1); and Streptococcuspneumoniae (0.125 vs 0.5 µg ml-1). Tedizolid MIC90s associated with different infections did not show significant differences, and the drug exhibited excellent activity against surveyed Gram-positive pathogens associated with HAP, SSTI and BSI, including linezolid-nonsusceptible strains. These data suggest that tedizolid could be an alternative to linezolid for the treatment of infections caused by Gram-positive organisms.

[The role of peripheral blood mononuclear cells (PBMC) of HBV-infected mothers in the intrauterine infection of their fetuses].

OBJECTIVE: To study the role of the HBV-infected mothers' PBMC in intrauterine transmission of HBV to their fetuses. METHODS: Thirty pregnant women with serum HBV DNA negative and PBMC HBV DNA positive and their newborns were used as the study group. Ten pregnant women with serum HBV negative and their infants served as the control group. HBV DNA in serum and in PBMC was detected using nested polymerase chain reaction (n-PCR). The mothers' PBMC in newborns' peripheral blood was examined using heminested-PCR. RESULTS: Four newborns were serum HBV DNA positive and 8 newborns were HBV DNA positive in PBMC in the study group. Among them, 2 newborns were HBV DNA positive in both serum and PBMC, 6 cases were positive in PBMC only, and 2 cases were positive in serum only. Five mothers had the GSTM1 gene; and it was not detected in 3 newborns. Among the 8 newborns with HBV DNA positive in PBMC, 3 did not have the GSTM1 gene, at the same time their mothers possessed the GSTM1 gene. Mothers' PBMC were detected in all of these three newborns' peripheral blood. HBV DNA in serum and in PBMC of the control group infants were all negative. CONCLUSION: HBV-infected PBMC of the mother may serve as a vector in HBV intrauterine infection.

[Study on intrauterine infection of hepatitis B virus in pregnant women with hepatitis B surface antigen and hepatitis B e antigen negative].

OBJECTIVE: To explore the significance of intrauterine infection of hepatitis B virus in pregnant women with hepatitis B surface antigen (HBsAg) and hepatitis B e antigen (HBeAg) negative by nested polymerase chain reaction (PCR). METHODS: Twenty-four pregnant women with HBsAg and HBeAg negative but other HBV markers positive together with their infants were included as study group. Sixteen pregnant women with HBV marker negative and their infants were in the control group. HBV DNA in sera and peripheral blood mononuclear cells (PBMCs) of two groups was detected by nested PCR respectively. RESULTS: (1) In the study group, the positive rates of HBV DNA of pregnant women were 33% (8/24) in the sera and 42% (10/24) in PBMCs. Three women were detected HBV DNA in both serum and PBMCs. The rate of HBV infection was 63% (15/24); (2) also in the study group, the positive rates of HBV DNA of the infants were 13% (3/24) in the sera and 25% (6/24) in PBMCs. One newborn was detected HBV DNA in both serum and PBMCs, the rate of intrauterine infection of HBV was 33% (8/24); (3) HBV DNA was detected in sera and/or in PBMCs from four newborns of pregnant women with HBV DNA positive only in PBMCs, the positive ratio was 4/7. CONCLUSIONS: HBV intrauterine infection is possible in pregnant women with HBsAg and HBeAg negative. Detecting HBV-DNA in sera and PBMCs of pregnant women and their newborns by PCR is important clinical significance.