Objective:To investigate the prognostic factors of severe patients with bloodstream infection (BSI) caused by Enterobacteriaceae bacteria. Methods:Patients suffered from BSI caused by Enterobacteriaceae bacteria admitted to department of critical care medicine of Binzhou Medical University Hospital from October 2016 to October 2019 were enrolled. The information of gender, age, combined shock, acute physiology and chronic health evaluationⅡ(APACHEⅡ), sequential organ failure assessment (SOFA), sensitivity of initial antibiotics, as well as the baseline of procalcitonin (PCT), white blood cell count (WBC), platelet (PLT), albumin (ALB) were collected. The 72-hour PCT clearance rate (72 h PCTc) was calculated after 72 hours' treatment. According to the clinical outcome after 28 days, the patients were divided into recovery group and death group. The differences of clinical indicators between the two groups were compared, and then the statistical significant variables were further performed by Logistic regression to analyze the factors affecting the prognosis of patients. The receiver operating characteristic (ROC) curve was drawn to evaluate the predictive efficacy of the factors in severe BSI. Results:A total of 86 patients were enrolled, among whom 54 cases recovered while 32 cases died, and the 28-day mortality was 37.2%. There was no significant difference in gender, age, sensitivity of initial antibiotics, baseline levels of PCT and WBC between two groups. In the death group, the shock incidence, APACHEⅡscore, SOFA score were significantly higher than those in recovery group [shock incidence: 84.4% (27/32) vs. 46.3% (25/54), APACHEⅡ: 24.94±7.65 vs. 17.02±6.57, SOFA: 11.00±3.27 vs. 6.30±2.65, all P < 0.01]; the PLT and ALB baseline levels, 72 h PCTc were significantly lower than those in recovery group [PLT (×10 9/L): 73.38±49.15 vs. 138.69±101.80, ALB (g/L): 25.47±5.91 vs. 28.59±4.53, 72 h PCTc: -44 (-170, 27)% vs. 63 (40, 77)%, all P < 0.01]. The above 6 variables were included in Logistic regression. The results showed that SOFA score was a risk factor for death in these patients [odds ratio ( OR) = 1.930, P = 0.037], while 72 h PCTc and ALB were protective factors ( OR values were 0.043, 0.783, P values were 0.008, 0.047). The SOFA, 72 h PCTc and ALB can be used to predict the prognosis of severe BSI, and the diagnostic value of the combination of three factors was the largest [area under the ROC curve (AUC) = 0.953, 95% confidence interval (95% CI) was 0.909-0.997], the sensitivity was 100%, and the specificity was 79.6%. Conclusions:Severe patients with BSI caused by Enterobacteriaceae bacteria had a high mortality. Higher SOFA score, and lower ALB and 72 h PCTc predicted the adverse outcome. The combination of the three factors has the greatest prognostic efficacy.

Aflatoxin B1(AFB1)is a secondary metabolite produced by Aspergillus aflatoxin and Aspergillus parasiticus.It has strong immunotoxicity and carcinogenicity and seriously harms the health of humans and livestock.Therefore,this study aims to explore the effect of selenomethionine(SeMet)in alleviating AFB1-induced thymic damage.Fifty 35-day-old rabbits were randomly divid-ed into 5 groups,with 10 rabbits in each group.They are the control group,AFB1 group,AFB1+0.2Se group(0.2 mg/kg SeMet),AFB1+0.4Se group(0.4 mg/kg SeMet)and AFB1+0.6Se group(0.6 mg/kg SeMet).The test period was 21 d.On the 17th day,each rabbit in the AFB1 group and each SeMet group was gavaged with AFB1(0.3 mg/kg)every day for 5 consecutive days.Rabbit thymus tissue was taken for HE,TUNEL and PCNA detection.ELISA was used to detect the ex-pression of inflammatory factors in thymus tissue,and GSH-Px,T-AOC and MDA kits were used to detect oxidative stress indicators in thymus tissue.The results showed that AFB1 exposure caused a very significant increase in MDA levels in rabbit thymus tissue by 116.04％,and a signifi-cant decrease in the activities of antioxidant enzymes GSH-Px and T-AOC by 29.20％and 52.17％respectively.In addition,AFB1 induced an inflammatory response in the thymus,promoting TNF-a secretion to increase by 124.71％,IL-6 by 174.72％,and IL-1β by 62.38％compared with the con-trol group.SeMet pretreatment significantly improved the pathological changes of the thymus in rabbits and reduced its oxidative stress and inflammatory response.Therefore,we confirmed that SeMet alleviates AFB1-induced thymic damage and improves the immune performance of rabbits.