A multicenter retrospective cohort study on the attributable risk of patients with Acinetobacter baumannii sterile body fluid infection / 中国感染控制杂志

Objective To investigate the attributable risk(AR)of Acinetobacter baumannii(AB)infection in criti-cally ill patients.Methods A multicenter retrospective cohort study was conducted among adult patients in inten-sive care unit(ICU).Patients with AB isolated from sterile body fluid and confirmed with AB infection in each cen-ter were selected as the infected group.According to the matching criteria that patients should be from the same pe-riod,in the same ICU,as well as with similar APACHE Ⅱ score(±5 points)and primary diagnosis,patients who did not infect with AB were selected as the non-infected group in a 1:2 ratio.The AR was calculated.Results The in-hospital mortality of patients with AB infection in sterile body fluid was 33.3％,and that of non-infected group was 23.1％,with no statistically significant difference between the two groups(P=0.069).The AR was 10.2％(95％CI:-2.3％-22.8％).There is no statistically significant difference in mortality between non-infected pa-tients and infected patients from whose blood,cerebrospinal fluid and other specimen sources AB were isolated(P＞0.05).After infected with AB,critically ill patients with the major diagnosis of pulmonary infection had the high-est AR.There was no statistically significant difference in mortality between patients in the infected and non-infec-ted groups(P＞0.05),or between other diagnostic classifications.Conclusion The prognosis of AB infection in critically ill patients is highly overestimated,but active healthcare-associated infection control for AB in the ICU should still be carried out.

Comparison of immune responses induced by recombinant attenuated Salmonella typhi carrying eukaryotic expression plasmid or prokaryotic expression plasmid of HCV core protein / 生物工程学报

Hepatitis C virus (HCV) core protein is considered to be an attractive candidate for development of protective HCV vaccines. However, this protein may attenuate the induction of systemic immune responses due to its immunomodulatory properties. In this study, we constructed a HCV core gene-containing eukaryotic expression plamid pCI-C, and an in vivo-inducible prokaryotic expression plasmid pZW-C, and transformed the recombinant plasmids into an attenuated Salmonella typhimurium aroA strain SL7207. The resulting bacterial strains SL7207/pCI-C and SL7207/pZW-C were used to orally immunize BALB/c mice, and the immune responses specific to HCV core protein were assessed. Immunization with the recombinant bacteria SL7207/pCI-C led to a persistent drop in percentage of CD3 CD4 T cells, and induced a weak anti-core IgG production. Splenocytes from SL7207/pCI-C immunized mice developed a relatively weak proliferation response and inferior cytotoxic activity compared to those from the mice immunized with bacteria SL7207/pZW-C. Boost immunization with SL7207/ pCI-C yielded limited improvement in immune strength, while the boost with bacteria SL7207/pZW-C significantly enhanced the immune response. These results suggest that de novo synthesis of native HCV core protein may blunt the induction of immune responses. Attenuated S. typhimurium carrying HCV core protein could efficiently activate systemic cellular and humoral responses, and may be a promising strategy for the development of core-based HCV vaccines.

Cause of HBeAg false-negative reaction and it countermeasures / 第二军医大学学报

Objective: To analyze the cause of HBeAg (one of HBV markers) false-negative reaction during ELISA examination and to discuss its countermeasures. Methods: The patients who were HBsAg (+), HBcAb (+) and HBeAg (-) by ELISA examination were further detected with the reagents of 4 different manufacturers in 2 steps: (1) The serum samples positive of HBsAg and HBcAb by ELISA using reagent A were further detected by qualitative analysis and Double-antibody sandwich ELISA using reagent A, B and C. (2) Reagent D (chemiluminescence method) was used to confirm the diagnosis if the results were positive or weakly positive of HBeAg, or the D values were within a specific range by ELISA using reagent A, B or C. The result of reagent D was taken as the final result. Results: The 274 sera negative of HBeAg were still negative when using reagent A, with the false-negative rate being 2.18%; 5 sera were positive when using reagent B, with false-negative rate being 0.36%; and 6 sera (including the 5 positive ones using reagent B and 1 negative case using reagent A and B) were positive when using reagent C, without false-negative case. All the 6 positive samples were confirmed by chemiluminescence using reagent D. Conclusion: It is suggested that ELISA examination using reagent A or B can lead to false-negative results of HBeAg. HBsAg (+), HBcAb (+) and HBeAg (-) sera in ELISA examination should be examined with combinations of reagents of different manufacturers.