Objective To investigate the clonal relatedness of A.baumannii isolates from senile patients by conducting cross-sectional and longitudinal studies on antimicrobial susceptibility profiling and genomic diversity.Methods Cross-sectional study was done among the 170 non-repetitive A.baumannii isolates which were collected from senile patients during two years.Longitudinal study was conducted among 77 A.baumannii collected from 8 senile patients within longtime hospitalization.Results 75.3 ％ of the 170 isolates were non-susceptible to carbapenems,and the phenotype were XDR or MDR which spread evenly all over the senile wards.The isolates belonged to 36 pulsotypes determined by PFGE.Groups Ⅰ (contain119 isolates) were major epidemic strains,which were CRAB with XDR phenotype.In longitudinal study,comparison of pulsotypes was performed for each patient and all isolates were clustered into group Ⅰ except one isolate.All the 77 isolates were XDR.Conclusion Extensive drug-resistance of A.baumannii was a serious problem in the gerontal wards.Clone dissemina tion was the most important style of XDR strains spread.Horizontal infection control measures to interrupt person-to-person transmission should be reinforced to reduce the further spread of XDR A.baumannii.

Objective To set up a method of stools protein extraction,analysis and identification in order to get the new nonin-vasive indicators of human digestive diseases.Methods The stools proteins,collected from healthy persons,the patients with atrophic gastritis,those who suffed from gastric carcinoma and postoperative patients with gastric carcinoma respectively, were extracted in three different ways including saline,Tris-HCl buffer and Urea buffer,the best way was selected by using SDS-PAGE,then a preliminary analysis of stools proteins was performed by 1D LC-MS/MS.Results The methods of saline and Tris-HCl buffer could get more stools proteins than the method of urea.The proteins in stools from the healthy persons, the patients with atrophic gastritis,the patients with gastric carcinoma and postoperative patients with gastric carcinoma were all abundant and more than one hundred.There was a significant difference in stools protein maps among the various populations.Alpha1-antitrypsin,a number of immunoglobulin and keratin were identified in the stools from patients with gastric carcinoma but not postoperative patients with gastric carcinoma and the healthy persons.Conclusions In this re-search,there was a significant difference in stools protein maps among the healthy persons,the patients with atrophic gastri-tis,the patients with gastric carcinoma and postoperative patients with gastric carcinoma,not only the composition of stools proteins,but also the abundance of same proteins.Therefore,using proteomics technologies to screening of the noninvasive indicators in human stools is viable.The study recommended that the noninvasive indicators in human stools should be iden-tified with quantitative differences analysis combination of quality of mass spectrometer method in the future research.

Objective:To evaluate the measurement agreement of Roche 25(OH)D immunoassay(evaluation method) with LC-MS/MS (reference method).Methods:A total of 909 residual serum samples from routine health check participants were collected from May to June in 2019. 25(OH)D concentrations were measured by evaluation method and LC-MS/MS, respectively. Passing-bablok regression, intraclass correlation coefficient (ICC), Bland Altman plots and Kappa test were used to analyze the consistency and bias on the results derived from the two measurement methods.Results:The 25(OH)D concentration derived from evaluation method was significantly different from those from LC-MS/MS method ( P<0.001). Slope of regression for evaluation method and LC-MS/MS was 0.962(95% CI 0.919-1.007), while intercept was -0.185 (95% CI -1.191-0.745). The ICC was 0.765 (95% CI 0.735-0.792). Altman plot showed that the average deviation between evaluation method and LC-MS/MS was -0.902 ng/ml (0.300%). The coincidence rate of evaluation method′s judgment of vitamin D sufficiency, insufficiency and deficiency with LC-MS/MS was 83.39%, and the weighted Kappa values was 0.790. Conclusion:Roche automatic 25(OH)D immunoassay shows acceptable correlation and agreement with LC-MS/MS, however, it is to note that the deviation between immunoassay and LC-MS/MS may lead to wrong judgment of vitamin D nutritional status. It is recommended that each laboratory should establish own corresponding reference values for 25(OH)D concentrations derived from these two methods.