[Effects of antibiotic stewardship on neonatal bloodstream infections].

OBJECTIVE: To investigate the effects of antibiotic stewardship on the pathogen and clinical outcome of neonatal bloodstream infections (BSIs). METHODS: A retrospective study was performed on neonates with BSIs who were admitted to the neonatal ward in the years of 2010 (pre-stewardship) and 2013 (post-stewardship) for pathogens, antibiotic resistance, antibiotic use, and clinical outcomes. RESULTS: The admission rate of BSIs (6.47% vs 2.78%) and the incidence of nosocomial BSIs (0.70% vs 0.30%) in 2013 were significantly higher than in 2010 (P<0.01). However, there were no signicant differences in the clinical outcomes between the years of 2010 and 2013 (P>0.05). The four most common pathogens isolated from blood cultures, Staphylococcus haemolyticus, Staphylococcus epidermidis, Klebsiella pneumoniae ssp pneumoniae and E.coli, were similar between the two years. There were no significant differences in the detection rates of extended spectrum ß-lactamase-positve Klebsiella pneumoniae ssp pneumoniae or E.coli between the two years. The detection rates of methicillin-resistant Staphylococcus/ß-lactamase-positive Staphylococcus haemolyticus and Staphylococcus epidermidis were similar between the two years (P>0.05). CONCLUSIONS: Since the implementation of antibiotic stewardship, there has been no marked variation in the common pathogens and their antibacterial resistance in neonatal BSIs. The antibiotic stewardship could promote the recovery of patients with BSIs.

QTL Mapping and Validation of Adult Plant Resistance to Stripe Rust in Chinese Wheat Landrace Humai 15.

Stripe rust caused by Puccinia striiformis f. sp. tritici (Pst) is a devastating foliar disease that affects common wheat and barley throughout the world. The reasonable deployment of adult plant resistance (APR) wheat varieties is one of the best methods for controlling this disease. Wheat landraces are valuable resources for identifying the genes/QTLs responsible for disease resistance. Humai 15 is a Chinese spring wheat landrace and it has exhibited adequate levels of APR to the prevalent Pst races in field environments for many years. In this study, a population of 177 recombinant inbred lines (RILs) was derived from Humai 15 × Mingxian 169. After screening based on a 90K chip array using 45 RILs and Kompetitive Allelic Specific PCR marker genotyping for the population of RILs, a major effect QTL in Humai 15 was located on the centromere of chromosome 2B, where it accounted for up to 47.2% of the phenotypic variation. Two other minor QTL genes from Humai 15 were located on chromosome arms 3BS and 4BL. The Yr18 gene was identified on chromosome arm 7DS in Mingxian 169.

[Construction and expression of ricin A chain and green fluorescent protein fusion gene in E. coli].

OBJECTIVE: To study the expression and purification of a fusion protein of ricin A chain (RTA) and green fluorescent protein (GFP). METHODS: The DNA sequence encoding ricin A chain was inserted into pEGFPC1 first to make the template sequence of the fusion protein. The fusion gene was amplified from the plasmid pEGFP-RTA by PCR, and directly subcloned into T vector. The fusion gene then was cloned into expression vector pET-28a(+), and the sequence was confirmed by sequencing. Expression was induced by IPTG in E. coli BL21(DE3). The fusion protein was purified by metal chelated affinity chromatography. The cytotoxicity of fusion protein was analyzed by the MTT assay in HepG2 and Hela cells. RESULTS: The fusion protein of ricin A chain and GFP could be produced in E. coli transformed with the expression plasmid of pET-28a(+)-GFP-RTA. The molecular weight of the recombinant protein was measured by SDS-PAGE. The fusion protein showed a green fluorescence and had a similar cytotoxicity of RTA. CONCLUSION: A recombinant fusion protein of RTA and GFP expressed in E. coli is possessed of similar biological activity of individual GFP and RTA, which could be used in study of the intracellular trafficking and translocation of RTA.

[Studies on application of APAGE in male sterile wheat with alloplamic cytoplasm].

Four male sterile wheat with Aeglops kotschyi, Ae. variabilis, Ae. ventricosa and Ae. bicornis cytoplasm, were crossed with some wheat materials, and from the crosses a series of maintenance lines were selected. The APAGE(acid polyacrylamide gel electrophoresis) analysis indicated that most maintenance lines possessed the gliadin marker Gld1B3 of 1BL/1RS translocation chromosome. The root tip chromosomes of this maintenance lines had two satellite chromosomes, but other maintenance lines without Gld1B3 marker had the same four satellite chromosomes as other common wheat. Three male sterile wheats with Aeglops kotschyi, Ae. variabilis, Ae. ventricosa cytoplasm had the same fertility, but the male sterile wheat with Ae. bicornis cytoplasm could produce male sterile. Meantime, the paper discussed application of APAGE technology in breeding of non-1BL/1RS male sterile wheat.

[Identification of wheat and barley hybrid offspring by GISH and PAGE].

Genomic in situ hybridization (GISH) and polyacrylamide gel electrophoresis (PAGE) of wheat seed were used to identify the barley chromosome in offspring of wheat and barley hybrid. A sires of alien addition lines, alien substitution lines and translocation lines were detected by GISH. WBA984 and WBA9812 were alien addition lines, WBS0215 and WBS0264 were alien substitution lines,and WBT02125 and WBT02183 were translocation lines in chromosome terminal. SDS-PAGE analysis and A-PAGE patterns indicated that WBA9812 were 5H alien addition line, WBS0264 was 1 B/5H alien substitution line, and WBT02125 was 1 BL/5HL translocation line.