ABSTRACT
Objective To investigate antimicrobial resistance of Escherichia coli (E.coli )isolated from patients with bloodstream infection,and provide evidence for rational use of antimicrobial agents in clinical practice.Methods BacT/A-lert automated blood culture system and VITEK 2 automated identification system were used for bacterial culture and identi-fication.Antimicrobial susceptibility testing and detection of extended-spectrum β-lactamases (ESBLs)-producing strains were performed by Kirby-Bauer method.Results From 2009 to 2011 ,a total of 235 strains of E.coli were isolated from patients with bloodstream infection,90 (38.30%)of which were ESBLs positive strains.The resistant rates of ESBLs-producing strains to ampicillin,cefotaxime and ceftriaxone were all 100%,but susceptibility rate to imi-penem/cilastatin and meropenem were all 100%,to cefmetazole and amikacin were >90%.The resistant rate of non-ESBLs-producing strains to ampicillin was the highest (70.63%),susceptibility rate to imipenem/cilastatin and meropenem were both 100%,to amikacin,cefotaxime,and cefmetazole were all >95%.The resistant rate of ES-BLs-producing strains was significantly higher than that of the non-ESBLs-producing strains.Ofβ-lactamase inhibi-tor,only susceptibility rate of ESBLs-producing E.coli to cefoperazone/sulbactam was>90%,susceptibility rates to piperacillin/tazobactam and ticarcillin/clavulanate were both<80%.Conclusion Antimicrobial resistant rate of ESBLs-producing strains causing bloodstream infection is high,individualized treatment strategies should be made according to antimicrobial resistance of bacteria causing infection in patients.
ABSTRACT
Objective To develop a rapid expansion assay and determine the predominant epitope for HBV-specific CD8 T cells from peripheral blood mononuclear cells(PBMC) of patients with acute hepatitis B(AHB).Methods PBMC were isolated from a patient with HLA-A2 positive AHB,and the frequency of HBV-specific CD8 T-cells was determined using 3 kinds of HLA-A2 antigenic peptide florescence-labeled pentamer agents,i.e.S183-191 and S335-343 derived from HLA-A2 restricted HBsAg epitope,and C18-27 derived from HBcAg epitope.Cytokines and corresponding epitopic peptides were used for induction of positive CD8 T-cell expansion and enrichment in PBMC for 1-2 weeks.T epitope-specific CD8 T-cells were quantified and sorted by flow cytometry.Results After cultivation with antigenic peptide stimulation and proper cultural condition,the frequency increased significantly in the pentamer positive HBV-specific CD8 T cells in total CD8 T cells.The peak value was observed in 2-week cultivation.At the time the HBV-specific CD8 T cell frequencies increased from 0.21% to 15.17% for S183-191,and from 0.44% to 1.79% for S335-343,representing 73.8-folds and 3.1-folds increase for each epitope respectively.However,the frequency of C18-27-specific CD8 T-cells was negative and without obvious proliferation after stimulation.Conclusions Under stimulation of HBV epitopic peptide in proper culture condition,the specific CD8 T lymphocytes may be induced and expanded in quantity via sort-term conditioned culture.CD8 T cells specific for S183-191 may play an important role in the control of acute HBV infection.
ABSTRACT
171.1?mol/L) was 25.0%, 37.7% and 46.3%, the percentage of the fulminating hepatitis was 3.0%, 5.9% and 14.0%, and the mean hospital stay days for the convalescent patients were 31.59?18.97, 31.13?13.70 and 37.51?18.33 days, respectively. All these variables were significantly higher in aged group compared with youth and middle-aged groups. The levels of alanine transaminase (ALT) lowered significantly with the advance of age, and they were 1 711.7?1 063.4, 1 423.0?913.2 and 1 162.7?792.5U/L, respectively. The same was true in serum albumin and choline esterase (ChE). On the other hand, the percentage of acute hepatitis without jaundice decreased to 17.9%, 6.4%and 2.5% from the youth to the aged. However, TBIL on admission (131.41?106.97 vs 169.60?136.11 vs 164.36?106.22?mol/L) and the elevation of the peak of TBIL (135.01?109.15 vs 186.08?150.64 vs 209.63?143.74?mol/L) of the middle-aged and the aged were significantly higher than those of the youth. There was no significant difference in the symptoms, the ratio of direct to total bilirubin, mortality to complications among them. Furthermore, the serum IgM and IgG antibodies against HEV were negative in about 8.1% of the patients with HEV. Conclusion With a higher incidence and more severe hepatic damage, the middle-aged and the aged patients need a longer duration for recovery than the young patients.