Carriage of Clostridioides difficile in healthy infants in the community of Handan, China: A 1-year follow-up study.

OBJECTIVE: Clostridioides difficile may colonize healthy infants and young children asymptomatically and for the long-term. C. difficile genotypes and the rate and determinants of colonization differ substantially and vary among countries and regions. A 1-year follow-up study was performed to determine the incidence, kinetics and influencing factors of C. difficile intestinal colonization. METHODS: Twenty-nine healthy infants (14 girls and 15 boys) living at home with their parents in Handan City were followed by survey from birth to 1 year of age, specifically from October 2014 through December 2015. C. difficile isolates were typed by PCR ribotyping and analyzed for the presence of toxin genes. RESULTS: During the follow-up study period in the first year of life, 20 of the 29 total enrolled infants acquired C. difficile. A total of 437 fecal samples were obtained, and 111 (25.4%) samples contained C. difficile, including 79 (71.2%) toxigenic strains. The toxigenic isolates comprised six PCR ribotypes, and two PCR ribotypes were identified as nontoxigenic strains. CONCLUSION: Our study showed that C. difficile colonization increase with age during the 12-month period, and the dominant toxigenic types of C. difficile isolates in infants were those involved in long-term colonization. Feeding patterns may affect the dynamic progress of C. difficile colonization.

Epidemiological investigation of Clostridioides difficile colonization in Chinese community infants.

Clostridioides difficile is a colonizer of the human gut; asymptomatic colonization has been reported to be more common in infants and is highly variable across regions even with no symptoms of diarrhea or death. Antibiotic treatment strategies might increase the antibiotic resistance of C. difficile. We performed a one-point study involving 1098 healthy infants (0-36 months) to address the deficiency of reports on C. difficile colonization in Chinese community infants. The C. difficile colonization rate was 22.8% (250/1098), and more than half of the strains (55.2%) were toxigenic isolates. Among the 138 toxigenic isolates, 111 were of the A+B+CDT- genotype, 26 strains were A-B+CDT-, and one strain was A+B+CDT+. Fifteen different PCR ribotypes were found among the 250 isolates, and PCR-ribotype HB03 appeared to be dominant type, accounting for 19.6% (49/250). High levels of resistance to antimicrobial agents were observed. Our study showed that age and hospitalization before stool collection were positively correlated with the C. difficile colonization rate, whereas the delivery term was negatively related to the colonization rate. Particular attention should be paid to the increasing resistance of C. difficile to rifamycin.

[Effect of water-nitrogen coupling on photosynthesis and ultrastructure of cucumber leaves under CO2 enrichment]. / CO2åŠ å¯Œä¸‹æ°´æ°®è€¦åˆå¯¹é»„ç“œå¶ç‰‡å ‰åˆä½œç”¨å’Œè¶ å¾®ç»“æž„çš„å½±å“.

Using split plot and then-split plot design, effects of water-nitrogen coupling on photosynthesis and ultrastructure of cucumber (Cucumis sativus) (Jinyou No.35) under CO2 enrichment were investigated. The main plot had two CO2 concentrations: ambient CO2 concentration (400 µmol·mol-1, A) and doubled CO2 concentration (800±20 µmol·mol-1, E). The split plot had two treatments: no drought stress (95% of field capacity, W) and drought stress (75% of field capacity, D). The then-split plot contained low nitrogen treatment (450 kg·hm-2, N1) and high nitrogen treatment (900 kg·hm-2, N2). The results showed that under the condition of drought and high nitrogen, increasing CO2 enhanced the cucumber plant height, and no matter what kinds of water treatment, CO2 enrichment increased the leaf area significantly under high nitrogen. Under the condition of normal irrigation, the photosynthetic rate, stomatal conductance and transpiration rate of high nitrogen treatment were higher than low nitrogen treatment, while it was under the drought condition. Elevated CO2 enhanced the water use efficiency of cucumber leaf which increased with increasing nitrogen application rate. Under drought stress, cucumber adaxial surface porosity density was increased, and the CO2 enrichment and high nitrogen significantly reduced the stomatal density. Increasing nitrogen application improved the number of chloroplast, and reduced that of starch grains. Drought stress decreased the number of chloroplast, but tended to promote the number of starch grains. Drought stress increased the chloroplast length and width, and the size of the starch grains, while high nitrogen reduced the length and width of the chloroplast and starch grains. CO2 enrichment and high nitrogen increased grana thickness and layers (except ADN2), and the slice layer of EDN2 was significantly higher than that of ADN2. In conclusion, CO2 enrichment and suitable water and nitrogen could promote the development of chloroplast thylakoid membrane system, significantly increase the thickness of grana and the number of grana lamella, and effectively improve the chloroplast structure of cucumber, which would benefit the photosynthesis of cucumber plants and ability to utilize CO2 and water and nitrogen.

[Influence of anti-ICOS antibody on quantity and function of CD4(+);CD25(+);Foxp3(+);Treg from lymph and blood of rats with bronchial asthma].

AIM: To investigate the influences of anti-ICOS antibody (anti-ICOSAb) on quantity and function of CD4(+);CD25(+);Foxp3(+);Treg cells from lymph and peripheral blood of rats with bronchial asthma. METHODS: The mononuclear cells (MNC) from lymph and blood were co-cultured with anti-ICOSAb, and then the percentage of CD4(+);CD25(+);Foxp3(+);Treg cells were analyzed by flow cytometer (FCM) and the levels of IL-10 and TGF-ß1 in supernatants were determined by ELISA. RESULTS: The MNC were collected from lymph and blood at 0, 24 and 48 h after the last challenge, respectively, and the cells were cultured for 96 h in vitro. The percentage of CD4(+);CD25(+);Foxp3(+);Treg cells in the MNC from lymph was significantly higher than that from blood in each group (P<0.05); The percentage of CD4(+);CD25(+);Foxp3(+);Treg cells in the MNC from lymph and blood in asthma group was significantly lower compare with the normal control group (P<0.05); The percentage of CD4(+);CD25(+);Foxp3(+);Treg cells in the MNC from lymph and blood in the anti-ICOSAb group obviously decreased compare with the asthma group (P<0.05). At 0 h after the last challenge, the level of IL-10 in the supernatant of MNC from lymph and blood in the anti-ICOSAb group were significantly lower than that of the control and asthma groups (P<0.05), while there were no significant differences of TGF-ß1 expression in the supernatant of MNC from lymph and blood in each group at different time points. CONCLUSION: Blocking the ICOS/ICOSL signaling pathway by anti-ICOSAb could exacerbate the deficiency of CD4(+);CD25(+);Foxp3(+);Treg cells from lymph and blood in bronchial asthmatic rat, meanwhile inhibit the CD4(+);CD25(+);Foxp3(+);Treg cells secreting IL-10 at 0 h after the last challenge, but have no significant effect on the secretion of TGF-ß1.

[Changes and the clinical significance of CD4⁺ CD25⁺ regulatory T cells and Th17 cells in peripheral blood of infants with respiratory syncytial virus bronchiolitis].

AIM: To observe the percentages of CD4(+);CD25(+); regulatory T cells (Tregs) and Th17 cells and the levels of IL-10, TGF-ß and IL-17 in peripheral blood of infants with respiratory syncytial virus (RSV) bronchiolitis. The relationship between above cells, cytokines and RSV bronchiolitis was determined. METHODS: Thirty-three infants with RSV bronchiolitis, twenty-eight infants with non-RSV pneumonia and twenty-six healthy infants were enrolled. The percentages of Tregs and Th17 cells in peripheral blood were detected by flow cytometer (FCM), and the levels of IL-10, TGF-ß and IL-17 in plasma were determined by ELISA. RESULTS: The percentage of Tregs and the levels of IL-10 and TGF-ß in infants with RSV bronchiolitis were significantly lower than those in infants with non-RSV pneumonia and healthy infants (P<0.05), while the percentage of Th17 cells and the level of IL-17 in infants with RSV bronchiolitis were significantly higher than those in infants with non-RSV pneumonia and healthy infants (P<0.05). CONCLUSION: The imbalance between Tregs and Th17 cells in peripheral blood of infants with RSV bronchiolitis may be one of the pathogenesis of RSV bronchiolitis.

[Expression of RhoA in the lung tissue of acute lung injury rats and the influence of RhoA on the expression of IL-8 and IL-10].

AIM: To investigate the expression of RhoA in the lung tissue of acute lung injury (ALI) rats induced by oleic acid (OA) and explore the influence of RhoA on the level of IL-8 and IL-10 in serum. Discussion RhoA and acute lung injury relationship. METHODS: Establish rat oleic acid acute lung injury model, Wet/Dry weights (W/D) were detected. Pathological changes of the lung tissue were examined. The levels of IL-8 and IL-10 in serum were detected by ELISA and the expression of RhoA in homogenate of lung tissue was determined by PCR. RESULTS: W/D and ALI score in ALI group at 6, 12, 24 and 48 h were higher than those in control group (P<0.01) and intervention group at the same time point (P<0.05). The level of IL-10(ng/L) in serum in ALI group at 2, 6, 12, 24 and 48 h was remarkably higher than that in control group (P<0.01), but was lower compared with intervention group at the same time point (P<0.01). The level of IL-8(pg/L) in serum at 2, 6, 12, 24 and 48 h in ALI group were higher than those in control group(P<0.01) and intervention group at the same time point(P<0.01).Compared with that of control group, the expression of RhoA in homogenate of lung tissue in ALI group at 2, 6, 12, 24 and 48 h was higher(P<0.01), but there was no difference between ALI group and intervention group at the same time point(P>0.05). CONCLUSION: The expression of RhoA in lung tissue of ALI rats induced by OA is increased. RhoA expression increase that can cause lung damage degree increase in rats. RhoA can aggravate the pathology changes of ALI rats, which might be related to up regulating expression of IL-8 and down regulating expression of IL-10 by RhoA.