Clinical characteristics of patients with Staphylococcus aureus bloodstream infection and analysis of risk factors and predictive indicators for the development of septic shock / 国际检验医学杂志

Objective To investigate the clinical features of of patients with Staphylococcus aureus blood-stream infection and risk factors for septic shock.Methods A total of 51 patients diagnosed with Staphylococ-cus aureus bloodstream infection in the hospital from January 2018 to March 2023 were enrolled in the study.According to whether the patients developed septic shock,they were divided into septic shock group and non-septic shock group.The clinical data of the patients were collected,and the clinical laboratory indicators were detected on the day of blood culture samples were collected.Bacteria isolated from blood culture specimens of patients were identified and tested for drug sensitivity.The clinical data and clinical laboratory test indicators of the two groups were compared.Multivariate Logistic regression was used to analyze the independent risk factors of septic shock in patients with Staphylococcus aureus bloodstream infection.The receiver operating characteristic(ROC)curve was used to analyze the predictive value of clinical laboratory test indicators for septic shock in patients with Staphylococcus aureus bloodstream infection.Results Septic shock occurred in 12 of 51 patients,with an incidence of 23.5％.The proportion of patients with diabetes,gouty arthritis,the proportion of patients with long-term glucocorticoid use,the proportion of patients with respiratory tract in-fection,the proportion of patients who died,and the hospitalization cost in the septic shock group were higher than those in the non-septic shock group,and the differences were statistically significant(P＜0.05).Long-term glucocorticoid use was an independent risk factor for septic shock in Staphylococcus aureus bloodstream infection(P＜0.05).The combination of C-reactive protein(CRP),albumin(Alb),neutrophil/lymphocyte ratio(NLR)and procalcitonin(PCT)had high value in predicting septic shock in patients with Staphylococ-cus aureus bloodstream infection,and the area under the ROC curve was 0.983.Conclusion Long-term use of glucocorticoids can lead to an increased risk of septic shock in patients with Staphylococcus aureus blood-stream infection.The combined detection of CRP,Alb,NLR and PCT has a higher predictive value than single detection for septic shock in patients with Staphylococcus aureus bloodstream infection.

Analysis of risk factors for short-term death after allogeneic hematopoietic stem cell transplantation / 中国组织工程研究

BACKGROUND:Allogeneic hematopoietic stem cell transplantation is an effective and even the only way to cure various hematological diseases,but the short-term mortality rate is relatively high after transplantation. OBJECTIVE:To investigate the risk factors affecting the overall survival of patients with hematological diseases in the short term(within 100 days)after allogeneic hematopoietic stem cell transplantation,so as to reduce mortality and effectively prevent related risks in the short term(within 100 days)after allogeneic hematopoietic stem cell transplantation. METHODS:Clinical data of 585 patients with hematological diseases who underwent allogeneic hematopoietic stem cell transplantation at the Hematopoietic Stem Cell Transplantation Center of First Affiliated Hospital of Zhengzhou University from January 1,2018 to June 30,2021 were retrospectively analyzed.The risk factors that affected overall survival within 100 days after allogeneic hematopoietic stem cell transplantation were explored. RESULTS AND CONCLUSION:A total of 585 patients with hematologic diseases underwent allogeneic hematopoietic stem cell transplantation.92 patients died within 100 days after transplantation,with a mortality rate of 15.7%(92/585).The median age of death cases was 26.5 years old(1-56 years),and the median survival time of death cases was 48 days(0-97 days).Univariate analysis exhibited that age≥14 years old,acute graft-versus-host disease,grade IV acute graft-versus-host disease,bacterial bloodstream infection,as well as carbapenem-resistant organism bloodstream infection,were risk factors for overall survival within 100 days after allogeneic hematopoietic stem cell transplantation(P<0.05).Multivariate regression analysis showed that age≥14 years old,grades Ⅲ-Ⅳ acute graft-versus-host disease,bacterial bloodstream infection,and carbapenem-resistant organism bloodstream infections were independent risk factors for overall survival(within 100 days)in patients after allogeneic hematopoietic stem cell transplantation.Hazard ratios were 1.77(95%CI 1.047-2.991),7.926(95%CI 3.763-16.695),2.039(95%CI 1.117-3.722),and 3.389(95%CI 1.563-7.347),respectively.In conclusion,all-cause mortality rate after allogeneic hematopoietic stem cell transplantation is relatively high in the short term.A timely diagnosis and effective treatment of bacterial bloodstream infection and acute graft-versus-host disease are essential to improving allogeneic hematopoietic stem cell transplantation outcomes.

Changes and biological significance of ferroptosis in a mouse model of bloodstream infection induced by different bacteria / 中国组织工程研究

BACKGROUND:It is of great significance to find new diagnostic markers of the disease and molecular targets for the treatment of the disease and the alleviation of organ injury.Ferroptosis is a newly discovered form of cell death.Overactivation of ferroptosis in animal models of sepsis is associated with the activation of inflammatory response and the injury of the liver,heart,kidney and other important organs,but the relationship between ferroptosis and bloodstream infection is not very clear. OBJECTIVE:To study the changes and biological significance of ferroptosis in a mouse model of blood stream infection induced by different bacteria. METHODS:Blood stream infection models induced by gram negative bacteria Escherichia coli,Klebsiella pneumoniae and gram positive bacteria Staphylococcus aureus and Enterococcus faecalis were established in SPF-grade ICR male mice,with 42 mice in each group.The mRNA expression levels of ferroptosis marker genes transferrin receptor 1 and glutathione peroxidase 4 in the liver,myocardium and kidney were detected at 0.5,1,3,6,12,24 and 48 hours after modeling.Another 18 SPF-grade ICR male mice were selected and randomly divided into dimethyl sulfoxide(DMSO)control group,DMSO+Klebsiella pneumoniae group,and Ferrostatin-1+Klebsiella pneumoniae group,with 6 mice in each group.In the latter two groups,animal models of Klebsiella pneumoniae bloodstream infection were established by tail vein injection of Klebsiella pneumoniae suspension,and 5 mg/kg Ferrostatin-1 and an equal dose of DMSO were given intraperitoneally 1 hour prior to the modeling of bloodstream infection,respectively.Serum levels of alanine aminotransferase,aspartate aminotransferase,blood creatinine,blood urea nitrogen,phosphocreatine kinase isoenzyme,lactate dehydrogenase,and mRNA expression levels of ferroptosis marker genes in various tissues were assayed at 6 hours after modeling. RESULTS AND CONCLUSION:After bloodstream infection modeling,the mRNA expression levels of transferrin receptor 1 in the liver,myocardium and kidney of bloodstream infection mice with different bacteria increased first and then decreased;and the mRNA expression level of glutathione peroxidase 4 decreased first,then increased,and reached the peak at 6 hours after modeling.The changes in transferrin receptor 1 and glutathione peroxidase 4 mRNA levels in bloodstream infection mice induced by gram-negative bacteria were more significant than those in blood stream infection mice induced by gram-positive bacteria,especially in bloodstream infection mice induced by Klebsiella pneumoniae.At 6 hours after bloodstream infection induced by Klebsiella pneumoniae,the levels of alanine aminotransferase,aspartate aminotransferase,serum creatinine,blood urea nitrogen,creatine phosphate kinase isoenzyme,lactate dehydrogenase in mice were significantly increased.Before modeling,Ferrostatin-1 intervention significantly reduced the levels of alanine aminotransferase,aspartate aminotransferase,serum creatinine,blood urea nitrogen,creatine phosphate kinase isoenzyme,and lactate dehydrogenase.All these findings indicate that the activation of ferroptosis in bloodstream infection mice induced by different bacteria is obvious,and the activation of ferroptosis in bloodstream infection mice induced by gram-negative bacteria is more obvious.Inhibition of iron death significantly attenuates liver,myocardial,and kidney injury in the mouse model of bloodstream infection induced by Klebsiella pneumoniae.

Analysis of Treatment of Renal Atrophy Complicated with Multi-site Carbapenem-resist-ant Klebsiella Pneumoniae Infection / 医药导报

Objective To analyze the treatment of renal atrophy combined with multi-site carbapenem-resistant Kleb-siella pneumoniae(CRKP)infection,and to provide a reference for clinical rational drug use for such diseases.Methods Based on practical experience and referring to the latest literature,clinical pharmacists participated in the treatment of a case of renal atrophy complicated with multi-site CRKP infection.Recommendations were made,including adjusting the usage and dosage of meropenem,combining with polymyxin E,and timely de-escalation treatment.Results After the physician adopted the sug-gestion and adjusted the treatment plan,the patient's symptoms and infection indicators returned to normal,and the infection was effectively controlled.Conclusion Polymyxin E sodium methanesulfonate combined with high-dose meropenem had good clini-cal efficacy in the treatment of urinary tract and bloodstream infections caused by CRKP.

National bloodstream infection bacterial resistance surveillance report (2022) : Gram-negative bacteria / 中华临床感染病杂志

Objective:To report the results of national surveillance on the distribution and antimicrobial resistance profile of clinical Gram-negative bacteria isolates from bloodstream infections in China in 2022.Methods:The clinical isolates of Gram-negative bacteria from blood cultures in member hospitals of national bloodstream infection Bacterial Resistant Investigation Collaborative System（BRICS）were collected during January 2022 to December 2022. Antibiotic susceptibility tests were conducted by agar dilution or broth dilution methods recommended by Clinical and Laboratory Standards Institute（CLSI）. WHONET 5.6 and SPSS 25.0 software were used to analyze the data.Results:During the study period，9 035 strains of Gram-negative bacteria were collected from 51 hospitals，of which 7 895（87.4%）were Enterobacteriaceae and 1 140（12.6%）were non-fermenting bacteria. The top 5 bacterial species were Escherichia coli（ n=4 510，49.9%）， Klebsiella pneumoniae（ n=2 340，25.9%）， Pseudomonas aeruginosa（ n=534，5.9%）， Acinetobacter baumannii complex（ n=405，4.5%）and Enterobacter cloacae（ n=327，3.6%）. The ESBLs-producing rates in Escherichia coli， Klebsiella pneumoniae and Proteus spp. were 47.1%（2 095/4 452），21.0%（427/2 033）and 41.1%（58/141），respectively. The prevalence of carbapenem-resistant Escherichia coli（CREC）and carbapenem-resistant Klebsiella pneumoniae（CRKP）were 1.3%（58/4 510）and 13.1%（307/2 340）；62.1%（36/58）and 9.8%（30/307）of CREC and CRKP were resistant to ceftazidime/avibactam combination，respectively. The prevalence of carbapenem-resistant Acinetobacter baumannii（CRAB）complex was 59.5%（241/405），while less than 5% of Acinetobacter baumannii complex was resistant to tigecycline and polymyxin B. The prevalence of carbapenem-resistant Pseudomonas aeruginosa（CRPA）was 18.4%（98/534）. There were differences in the composition ratio of Gram-negative bacteria in bloodstream infections and the prevalence of main Gram-negative bacteria resistance among different regions，with statistically significant differences in the prevalence of CRKP and CRPA（ χ2=20.489 and 20.252， P<0.001）. The prevalence of CREC，CRKP，CRPA，CRAB，ESBLs-producing Escherichia coli and Klebsiella pneumoniae were higher in provinicial hospitals than those in municipal hospitals（ χ2=11.953，81.183，10.404，5.915，12.415 and 6.459， P<0.01 or <0.05），while the prevalence of CRPA was higher in economically developed regions（per capita GDP ≥ 92 059 Yuan）than that in economically less-developed regions（per capita GDP <92 059 Yuan）（ χ2=6.240， P=0.012）. Conclusions:The proportion of Gram-negative bacteria in bloodstream infections shows an increasing trend，and Escherichia coli is ranked in the top，while the trend of CRKP decreases continuously with time. Decreasing trends are noted in ESBLs-producing Escherichia coli and Klebsiella pneumoniae. Low prevalence of carbapenem resistance in Escherichia coli and high prevalence in CRAB complex have been observed. The composition ratio and antibacterial spectrum of bloodstream infections in different regions of China are slightly different，and the proportion of main drug resistant bacteria in provincial hospitals is higher than those in municipal hospitals.

Construction of a risk prediction model for bloodstream infection induced by carbapenem-resistant Klebsiella pneumoniae / 中国药房

OBJECTIVE To construct a risk prediction model for bloodstream infection （BSI） induced by carbapenem-resistant Klebsiella pneumoniae （CRKP）. METHODS Retrospective analysis was conducted for clinical data from 253 patients with BSI induced by K. pneumoniae in the First Hospital of Qinhuangdao from January 2019 to June 2022. Patients admitted from January 2019 to December 2021 were selected as the model group （n＝223）， and patients admitted from January 2022 to June 2022 were selected as the validation group （n＝30）. The model group was divided into the CRKP subgroup （n＝56） and the carbapenem- sensitive K. pneumoniae （CSKP） subgroup （n＝167） based on whether CRKP was detected or not. The univariate and multivariate Logistic analyses were performed on basic information such as gender， age and comorbid underlying diseases in two subgroups of patients； independent risk factors were screened for CRKP-induced BSI， and a risk prediction model was constructed. The established model was verified with patients in the validation group as the target. RESULTS Admissioning to intensive care unit （ICU）， use of immunosuppressants， empirical use of carbapenems and empirical use of antibiotics against Gram-positive coccus were independent risk factors of CRKP-induced BSI （ORs were 3.749， 3.074， 2.909， 9.419， 95%CIs were 1.639-8.572， 1.292- 7.312， 1.180-7.717， 2.877-30.840， P＜0.05）. Based on this， a risk prediction model was established with a P value of 0.365. The AUC of the receiver operating characteristic （ROC） curve of the model was 0.848 [95%CI （0.779， 0.916）， P＜0.001]， and the critical score was 6.5. In the validation group， the overall accuracy of the prediction under the model was 86.67%， and the AUC of ROC curve was 0.926 [95%CI （0.809， 1.000]， P＜0.001]. CONCLUSIONS Admission to ICU， use of immunosuppressants， empirical use of carbapenems and empirical use of antibiotics against Gram-positive coccus are independent risk factors of CRKP- induced BSI. The CRKP-induced BSI risk prediction model based on the above factors has good prediction accuracy.

Application of droplet digital PCR in etiological diagnosis of severe acute pancreatitis patients with suspected bloodstream infection / 中国感染控制杂志

Objective To explore the value of droplet digital polymerase chain reaction(ddPCR)in the etiological diagnosis of severe acute pancreatitis(SAP)patients with suspected bloodstream infection(BSI).Methods SAP patients admitted to the department of critical care medicine in a hospital July to September 2022 were enrolled.When BSI was suspected,venous blood was collected for both ddPCR detection and blood culture(BC)with antimi-crobial susceptibility testing(AST)simultaneously.The time required for two detection methods was recorded,and the detection results of ddPCR and BC were compared.The etiological diagnostic efficacy of ddPCR was calculated,and the correlation between the value of pathogen load detected by ddPCR and the level of infection parameters was explored.Results A total of 22 patients were included in the analysis,and 52 venous blood specimens were collec-ted for detection.BC revealed 17 positive specimens(32.7％)and 29 pathogenic strains,while ddPCR showed 41 positive specimens(78.8％)and 73 pathogenic strains.Detection time required for ddPCR was significantly lower than that of BC([0.16±0.03]days vs[5.92±1.20]days,P＜0.001).Within the detection range of ddPCR and taking BC results as the gold standard,the sensitivity and specificity of ddPCR were 80.0％and 28.6％,respective-ly.With the combined assessment of BSI based on non-blood specimen microbial evidence within a week,the sensi-tivity and specificity of ddPCR detection increased to 91.9％and 76.9％,respectively.ddPCR detected resistance genes of blaKPC,blaNDM/IMP,VanA/VanM,and mecA from 19,9,6,and 5 specimens,respectively.Correlation analysis showed a positive correlation between pathogen load and levels of C-reactive protein as well as procalcitonin(r=0.347,0.414,P＜0.05).Conclusion As a supplementary detection method for BC in BSI diagnosis,ddPCR has the advantages of higher sensitivity and shorter detection time,and is worthy of further exploration in clinical application.

Current status of maintenance hemodialysis-related infection in 124 medi-cal institutions in Guizhou Province / 中国感染控制杂志

Objective To understand the infection status of patients with maintenance hemodialysis(MHD)in Guizhou Province,and provide basis for the prevention and control of hemodialysis-related infection.Methods MHD patients in hemodialysis centers of 124 secondary and or higher grade medical institutions in Guizhou Province from July to December 2022 were surveyed.Survey content included the general conditions of patients,hemodialysis-related conditions,infection of pathogens of blood-borne diseases,and other infection-related conditions.Results A total of 15 114 MHD patients were surveyed,with age mainly ranging from 36 to＜60 years old(55.83％).Hemodialysis history ranged mainly from 1 year to＜5 years(59.37％),and the frequency of hemodi-alysis was mainly 3 times per week(73.91％).Autologous arteriovenous fistula(AVF)was the major vascular access for dialysis,with a total of 12 948 cases(85.77％).The main primary disease was chronic renal failure(99.89％).The infection rates of hepatitis B virus(HBV),hepatitis C virus(HCV),human immunodeficiency vi-rus(HIV),and Treponema pallidum in MHD patients were 5.29％,0.64％,0.24％,and 1.70％,respectively.HBV infection rates among MHD patients of different ages,different numbers of dialysis hospitals,and dialysis in-stitutions of different scales showed statistically significant differences(all P＜0.05).HCV infection rates among MHD patients of different ages,with different dialysis times and from institutions of different scales were signifi-cantly different(all P＜0.05).TP infection rates among MHD patients of different ages and different numbers of dialysis hospitals were all significantly different(all P＜0.05).Infection rates of HBV and HCV in MHD patients aged from 36 to 60 years old(not included)were relatively higher(6.10％and 0.84％,respectively).Patients with dialysis time ≥10 years had a higher HCV infection rate(1.64％).Infection rates of HCV,HIV,and TP in pa-tients dialyzed in medical institutions with ≥90 dialysis beds were relatively higher(0.74％,0.28％,and 1.94％,respectively).Medical institutions with＜30 dialysis beds had the highest HBV infection rate(18.64％).There were 9 cases(0.06％)of vascular puncture infection,12 cases(0.08％)of bloodstream infection,7 cases(0.05％)of vascular access-related bloodstream infection,and 30 cases(0.20％)of pulmonary infection.Vascular access-re-lated bloodstream infection rate and pulmonary infection rate among MHD patients with different types of vascular access showed statistically significant difference(all P＜0.05).Vascular access-related bloodstream infection rate(0.37％)and pulmonary infection rate(1.10％)of patients with non-cuffed catheters vascular access were higher than those of other types.Conclusion MHD patients in Guizhou Province are mainly middle-aged and young peo-ple,with more males than females.The dialysis frequency is mostly 3 times per week,and AVF is the major vascu-lar access.MHD patients are prone to complications such as infections of HBV,HCV,HIV,and TP,as well as bloodstream infection and pulmonary infection.

Risk factors for healthcare-associated bloodstream infection of carbape-nem-resistant Enterobacterales / 中国感染控制杂志

Objective To analyze the characteristics and influencing factors of healthcare-associated bloodstream infection(HA-BSI)of carbapenem-resistant Enterobacterales(CRE).Methods Retrospective nested case-control study was adopted.Fifty-six patients with CRE HA-BSI in a tertiary general hospital from January 2020 to Decem-ber 2022 were selected as the CRE group.With a 1:1 ratio,56 patients with carbapenem-sensitive Enterobacterales(CSE)BSI during the same period was selected as the CSE group.Distribution of infection strains and departments was analyzed,and the relevant factors for CRE BSI were analyzed by univariate and multivariate logistic regression analyses.Results The distribution of CRE BSI was mainly in intensive care unit(ICU,n=23,41.07％)and de-partment of hematology(n=17,30.36％).The main infection strains were Klebsiella pneumoniae(n=32,57.14％)and Escherichia coli(n=16,28.57％).Univariate analysis showed that malignant tumor,hospitalization history within 60 days,stay in ICU for＞48 hours before infection,mechanical ventilation,indwelling central venous cathe-ter,combined use of at least two kinds of antimicrobial agents,and duration of antimicrobial use ≥10 days were all related to CRE BSI(all P＜0.05).Multivariate logistic regression analysis found that stay in ICU＞48 hours before infection and duration of antimicrobial use ≥10 days before infection were independent risk factors for CRE HA-BSI(P＜0.05).Conclusion Clinical departments,especially ICU,should pay attention to the epidemiological history of patients,identify patients with high-risk factors for CRE BSI as early as possible,use antimicrobial agents ratio-nally and standardize invasive procedure,so as to reduce the occurrence of CRE HA-BSI.

Research advances in the prevention of catheter-related bloodstream infec-tion by locking solution / 中国感染控制杂志

Catheter-related bloodstream infection(CRBSI)is an important factor leading to death in patients with venous catheterization.Selection of catheter locking solution has become an important part in maintaining venous catheter.Locking solution with different chemical components have different effects on preventing CRBSI.There-fore,selecting a suitable and effective solution for locking is an important method to reduce the occurrence of CRB-SI.This paper reviews different types of domestic and foreign locking solutions with single or compound chemical compositions in the prevention of CRBSI,so as to provide theoretical reference for clinical health care workers in the selection and further research in locking solution.

Risk factors and mortality for carbapenem-resistant Acinetobacter baumannii bloodstream infection in elderly patients:a 10-year retrospective study / 中国感染控制杂志

Objective To assess the risk factors for carbapenem-resistant Acinetobacter baumannii(CRAB)bloodstream infection(BSI)and 28-day short-term mortality in elderly patients,and provide reference for the pre-vention and treatment of CRAB BSI.Methods Clinical data of patients aged ≥60 years and diagnosed with AB BSI in a hospital in Yulin City from January 2013 to December 2022 were retrospectively analyzed,including demogra-phic and microbiological characteristics,as well as clinical outcomes of the patients.Variables which were significant in univariate analysis were selected for multivariate analysis using binary logistic regression model and Cox propor-tional hazards model.Independent risk factors for infection were further determined,and survival analysis was per-formed using Kaplan-Meier curve.Results A total of 150 patients were included in the study,out of which 16 pa-tients(10.7％)had CRAB BSI and 134 had carbapenem-sensitive AB(CSAB)BSI.The 28-day short-term mortali-ty of AB BSI in elderly patients was 15.3％(23/150,95％CI:9.6％-21.1％),and the short-term mortality of CRAB BSI was higher than that of CSAB([56.3％,9/16]vs[10.4％,14/134]).Deep venous catheterization(OR:15.598,95％CI:1.831-132.910)and combined infections of other sites(OR:15.449,95％CI:1.497-159.489)were related to CRAB BSI in elderly patients.The independent risk factors for 28-day mortality in elderly patients with AB BSI were hemodialysis(OR:11.856,95％CI:2.924-48.076),intensive care unit admission(OR:9.387,95％CI:1.941-45.385),and pulmonary infection being suspected source of bacteremia(OR:7.019,95％CI:1.345-36.635).Conclusion The occurrence of CRAB BSI in elderly patients is related to the combined infection of other sites and deep vein catheterization.Hemodialysis,admission to ICU,and pulmonary infection being suspected source of bacteremia are independent risk factors for the prognosis of AB BSI in elderly patients.

Prevotella bloodstream infection:a 10-year single-center retrospective study / 中国感染控制杂志

Objective To improve clinicians'understanding on Prevotella bloodstream infection(BSI),reduce the rate of misdiagnosis and missed diagnosis,and broaden the ideas of diagnosis and treatment.Methods Clinical data of patients with Prevotella BSI at a hospital affiliated to a medical school of Nanjing University from May 2013 to May 2023 were collected.Risk factors,sources of infection,strains of infection,clinical manifestations,laboratory test results,treatment,and outcomes of patients with Prevotella BSI were retrospectively analyzed.Results A to-tal of 23 patients diagnosed with Prevotella BSI were included in analysis,15(65.2％)were males and 8(34.8％)were females.Most patients had related predisposing factors before BSI,such as surgical procedures(n=11,47.8％),malignant tumors(n=10,43.5％),diabetes(n=9,39.1％),and indwelling urinary catheter(n=10,43.5％),etc.There were 9 types of infected bacteria,mainly Prevotella buccalis(n=6,26.1％),Prevotella bivia(n=5,21.7％)and Prevotella intermedia(n=4,17.4％).The main sources of infection were hepatobiliary system(n=6,26.1％),abdominal and thoracic cavities(n=4,17.4％),as well as urogenital tract(n=4,17.4％).All pa-tients showed symptoms of chills and fever,with significantly elevated blood inflammation indicators.Four cases(17.4％)developed septic shock,and 18 cases(78.3％)had a good prognosis after appropriate anti-infection treat-ment.Conclusion When atypical BSI caused by Prevotella is suspected,predisposing factors should be removed as soon as possible,blood should be actively collected and performed culture,rational use of antimicrobial agents based on antimicrobial susceptibility testing is beneficial for rapid control of infection and improvement of prognosis.

Clinical characteristics and prognosis of carbapenem-resistant Klebsiella pneumoniae bloodstream infection in preterm infants / 中华传染病杂志

Objective:To investigate the clinical characteristics and prognosis of bloodstream infection caused by carbapenem-resistant Klebsiella pneumoniae (CRKP) in preterm infants, and to provide basis for early clinical diagnosis and infection control. Methods:The clinical data of infants with CRKP bloodstream infection admitted to the Preterm Infants Ward of Children′s Hospital Affiliated to Zhengzhou University from January 2015 to December 2022 were retrospectively analyzed. The risk factors for death in preterm infants caused by CRKP bloodstream infection were explored through multivariate logistic regression analysis, and the receiver operating characteristic (ROC) curve was used to analyze the clinical value of each factor on evaluating prognosis. The area under curves (AUC) of each factor in different ROC curve were compared by Delong′s test.Results:A total of 96 preterm infants with CRKP bloodstream infection were included, including 70 in the survival group and 26 in the death group. The first onset symptoms of CRKP bloodstream infection in preterm infants were persistent tachycardia (heart rate>180 per minute) (69 cases, 71.9%), fever (61 cases, 63.5%), and apnea (59 cases, 61.5%). There were 88(91.7%) cases of infection combined with septic shock, and 91(94.8%) cases required vasoactive drug support. Multivariate logistic regression analysis showed that the maximum vasoactive-inotropic score (VIS) within 48 hours of onset (odds ratio ( OR)=1.058, 95% confidence interval (95% CI) 1.022 to 1.095, P=0.001), concurrent purulent meningitis ( OR=8.029, 95% CI 1.344 to 47.972, P=0.022), and concurrent necrotizing enterocolitis (NEC) ( OR=10.881, 95% CI 1.566 to 75.580, P=0.016) were independent risk factors for death in preterm infants with CRKP bloodstream infection. The ROC curve showed that the AUCs for evaluating the prognosis of preterm infants with NEC and purulent meningitis were 0.784 and 0.711, respectively. The AUC for evaluating the prognosis of preterm infants with a maximum VIS ≥52.5 points within 48 hours of onset was 0.840, and the AUC for combining the three factors was 0.931. Compared with NEC and purulent meningitis, the AUC for combining factors was higher, the differences were statistically significant ( P=0.002, P<0.001). Conclusions:Preterm infants with CRKP bloodstream infection who have a maximum VIS ≥52.5 points within 48 hours of onset, with NEC and purulent meningitis have a higher risk of death.

Bloodstream infection by Rhodococcus corynebacterioides in a pediatric patient diagnosed with high-risk retinoblastoma / Infección del torrente sanguíneo por Rhodococcus corynebacterioides en un paciente pediátrico con diagnóstico de retinoblastoma de alto riesgo

Abstract Rhodococcus is a pathogen that is known to cause infections in animals and humans, mainly in cases of immunocompromised patients. A case of a pediatric cancer patient suffering from a bloodstream infection caused by Rhodococcus corynebacterioides was described in this work. Gram positive rods were isolated from blood cultures. The target bacterium was identified using a combination of biochemical tests, the MALDI-TOF mass spectrometry technique, and the analysis of the 16S rRNA sequence. Moreover, an antimicrobial susceptibility test was performed using the E-test. The isolated bacterium was identified as R. corynebacterioides. The 3-year-old patient was successfully treated with vancomycin and meropenem. This is the first published report of R. corynebacterioides in a pediatric patient diagnosed with retinoblastoma that developed a bloodstream infection. R. corynebacterioides should be considered among the opportunistic infectious agents affecting pediatric cancer patients.

Resumen Rhodococcus es un patógeno conocido por causar infecciones en animales y humanos, principalmente en pacientes inmunocomprometidos. En este trabajo se describe el caso de un paciente pediátrico con cáncer que presentó una infección del torrente sanguíneo causada por Rhodococcus corynebacterioides. A partir de hemocultivos, se aislaron bacilos gram positivos. La bacteria diana fue identificada usando una combinación de pruebas bioquímicas, por espectrometría de masas MALDI-TOF y por el análisis de la secuencia del gen 16S ARNr. Además, se realizó una prueba de sensibilidad a los antimicrobianos utilizando E-test. La cepa bacteriana se identificó como R. corynebacterioides. El paciente, de 3 años, fue tratado con vancomicina y meropenem, exitosamente. Este es el primer reporte de R. corynebacterioides como agente causal de una infección del torrente sanguíneo en un paciente pediátrico con retinoblastoma. R. corynebacterioides debe considerarse entre los agentes infecciosos oportunistas que afectan a los pacientes pediátricos con cáncer.

Characteristics analysis of epidemiological and antimicrobial resistance of 589 meliodosis bloodstream infection cases in Hainan / 中国热带医学

@#Objective　To provide data support for the prevention and control of melioidosis by analyzing epidemiological characteristics of melioidosis bloodstream infection and antibiotic resistance of its pathogen in Hainan Province from 2012 to 2021. Methods Data was collected from Hainan Antimicrobial Resistance Surveillance System, and WHONET 5.6 software was used to merge and analyze data. Results The case numbers of melioidosis bloodstream infection showed an increasing trend year by year from 2012 to 2021. The ratio of male to female patients was 4.6∶1, with 347 cases (58.91%) of patients aged 40-<60, the age group with the highest incidence. The number of cases from July to November were 424 cases (72.0%). Haikou and Sanya reported the largest case number, with 261 and 116 cases respectively. But there were no case reported from central area including Chengmai, Tunchang, Qiongzhong and Baoting. Burkholderia pseudomallei strains were isolated from both blood and other specimens in 105 of the 589 patients, with respiratory tract and wood specimens being the sites with the highest number of strains isolated other than blood; the resistance rates of Burkholderia pseudomallei to five antibiotics showed no obvious trend of change, with the lowest resistance rate to imipenem among the five drugs at 0.6%, followed by ceftazidime at 2.2%. Conclusion During the typhoon season, elderly, middle-aged male in coastal areas should pay attention to avoid or reduce their contact with mud and water. For patients with melioidosis bloodstream infection, imipenem or ceftazidime should be selected as early as possible for initial treatment.

Analysis of drug resistance and risk factors of multi drug resistant bacteria in bloodstream infection / 中国热带医学

@#Abstract: Objective To analyze the antimicrobial resistance rate and risk factors of multi drug resistant organisms (MDRO) in bloodstream infection for rational treatment. Methods　A total of 696 cases of bloodstream infections of Staphylococcus aureus, Enterococcus, Enterobacteriaceae (excluding Salmonella and Shigella), Pseudomonas aeruginosa and Acinetobacter in our hospital from 2017 to 2021 were selected, and 711 pathogenic strains were isolated from their whole blood samples. The antimicrobial resistance rates of various multi drug resistant strains were analyzed and the risk factors of MDRO infection were analyzed. Results　696 non repeated cases were screened out from 13 187 whole blood culture specimens, with a positive rate of 5.3%, and a total of 711 blood influenza pathogens were detected, among them, 350 strains of MDRO were detected with a detection rate of 49.23% (350/711). Among the pathogenic bacteria of bloodstream infection, Escherichia coli was the most, with 277 strains accounting for 38.96% (277/711), of which 201 strains were MDRO, accounting for 57.43% (201/350); followed by Klebsiella pneumoniae and Staphylococcus aureus, with 155 strains accounting for 21.80% (155/711) and 89 strains accounting for 12.52% (89/711), among which 43 strains of Klebsiella pneumoniae MDRO accounted for 12.29% (43/350) and 38 strains of Staphylococcus aureus MDRO accounted for 10.86% (38/350). The change trend of the three pathogens during 2017-2021 was not obvious. The drug sensitivity test showed that Escherichia coli and Klebsiella pneumoniae were highly resistant to cephalosporins and fluoroquinolones, and the drug resistance rate of aminoglycosides was relatively low. They had almost no resistance to cephalosporins and carbapenems. Staphylococcus aureus has a high resistance rate to lincomycin and macrolides, but no resistance to oxazolidinone, glycopeptides and glycylcyclins. There were 350 cases of MDRO infection and 361 cases of non MDRO infection. Univariate analysis showed that the age, sex, cardiovascular and cerebrovascular history, renal insufficiency, lung disease, hypoalbuminemia, hepatobiliary disease, electrolyte disorder and anemia of the patients had no statistical significance in MDRO infection (P>0.05); diabetes, urinary tract infection, surgical operation and burn were the influencing factors of MDRO (P<0.05). According to logistic analysis, diabetes, urinary tract infection, surgical operation and burn were the risk factors of MDRO infection (P<0.05). Conclusion　The infection of MDRO in patients with bloodstream infection is serious, and early prevention and control should be paid attention to, and the principle of graded use of antibiotics should be strictly observed, and the rational application should be carried out to actively and effectively control the production of MDRO.

Distribution and drug resistance analysis of pathogenic bacteria in a hospital blood culture, 2018-2022 / 中国热带医学

@#Abstract: Objective　To analyze the distribution and drug resistance of pathogenic bacteria in blood culture specimens of patients with bloodstream infections before and after COVID-19 (2018-2019 and 2020-2021), and to provide scientific basis and reference for rational treatment and effective control of bloodstream infections in the post-epidemic period. Methods Blood culture specimens were collected from patients in Zhongnan Hospital of Wuhan University in the two years before and after the COVID-19 outbreak (2018-2021). The Automated Blood Culture Systems were used to perform blood culture on blood specimens sent for clinical inspection, and the Vitek MS automatic bacterial identification mass spectrometer was used for strain identification and the Vitek 2 automatic bacterial drug susceptibility analyzer was used for drug susceptibility testing and drug resistance analysis. Results　Blood culture specimens were performed on 28 736 patients with suspected bloodstream infection submitted for inspection from January 2018 to December 2019, and a total of 2 181 strains of pathogenic bacteria were detected after removing duplicate strains, with a positive rate of 7.69%, including 1 046 strains of Gram-negative bacteria, accounting for 47.96%. From January 2020 to December 2021, blood culture specimens from 26 083 patients with suspected bloodstream infection were submitted for inspection, and a total of 2 111 strains of pathogenic bacteria were detected after excluding duplicate strains, with a positive rate of 8.09%, including 1 000 strains of Gram-negative bacteria accounted for 47.37%. The drug resistance of Klebsiella pneumoniae was relatively serious, and the sensitivity rate to ertapenem, polymyxin B and tigecycline was more than 90%. The main non-fermentative bacteria Acinetobacter baumannii was more than 50% sensitive to piperacillin/tazobactam, amikacin and polymyxin B. The sensitivity rates of Pseudomonas aeruginosa to piperacillin/tazobactam, ceftazidime, cefepime, amikacin, gentamicin, tobramycin, ciprofloxacin, levofloxacin, piperacillin and meropenem were more than 50%. Conclusions　In the two years before and after COVID-19, there are many types of pathogenic bacteria in bloodstream infection, but the distribution do not differ significantly. The pathogens of bloodstream infection are mainly distributed in ICU, hepatobiliary research institute, and nephrology department. Among them, Gram-negative bacteria such as Escherichia coli, Klebsiella pneumoniae and Acinetobacter baumannii are the main ones, and different pathogens showed great differences in drug resistance.

Analysis of 50 cases of bloodstream infection with Listeria monocytogenes / 中国热带医学

@#Abstract: Objective　To analyze the characteristics of bloodstream infection of Listeria monocytogenes and provide basis for the diagnosis and treatment of the disease. Methods　We retrospectively analyzed the cases of Listeria monomyrhosi bloodstream infection in Peking Union Medical College Hospital (PUMCH) from April 2012 to April 2022. The age, sex, onset time, underlying disease, symptoms, diagnosis, treatment and prognosis of the patients were analyzed, as well as the changes of white blood cells (WBC), neutrophils, lymphocytes, and C-reactive protein (CRP) before and after anti-infection treatment. Results　Fifty cases of Listeria monocytogenes bloodstream infection confirmed by blood culture were involved. The age of patients ranged from 0 to 82 (43.7±20.0) years old, among whom 20.0% were over 60 years old. The onset time of patients was the highest in spring (44.0%), followed by winter (24.0%), and relatively fewer in summer and autumn (14.0%-18.0%). The median diagnosis time was 3 days (1-60 days). After the etiological diagnosis, 45 patients (90.0%) had underlying diseases or pregnancy status, and 45 patients were adjusted to the target antibacterial treatment mainly with carbapenems (48.9%) and penicillins (44.4%). The level of WBC, neutrophils, lymphocytes, monocytes, and CRP after treatment were significantly lower than those pre-treatments (P<0.05). Among all patients, 36 cases (72.0%) were treated according to the Antimicrobial Treatment Guidelines for Fever Sanford, of which 26 cases (72.2%) were discharged from the hospital, two cases died, one case was transferred to other hospitals, and 7 cases had a poor prognosis. Conclusions　Autoimmune diseases, tumor diseases, pregnant patients are susceptible to Listeria monocytogenes infection. Penicillins are the first choice for effective empiric therapy. For the patients allergic to penicillins, trimethoprim/sulfamethoxazole or meropenem could be used.

A single-center study on the distribution and antibiotic resistance of pathogens causing bloodstream infection in patients with hematological malignancies / 中华血液学杂志

Objective: To study the incidence of bloodstream infections, pathogen distribution, and antibiotic resistance profile in patients with hematological malignancies. Methods: From January 2018 to December 2021, we retrospectively analyzed the clinical characteristics, pathogen distribution, and antibiotic resistance profiles of patients with malignant hematological diseases and bloodstream infections in the Department of Hematology, Nanfang Hospital, Southern Medical University. Results: A total of 582 incidences of bloodstream infections occurred in 22,717 inpatients. From 2018 to 2021, the incidence rates of bloodstream infections were 2.79%, 2.99%, 2.79%, and 2.02%, respectively. Five hundred ninety-nine types of bacteria were recovered from blood cultures, with 487 (81.3%) gram-negative bacteria, such as Klebsiella pneumonia, Escherichia coli, and Pseudomonas aeruginosa. Eighty-one (13.5%) were gram-positive bacteria, primarily Staphylococcus aureus, Staphylococcus epidermidis, and Enterococcus faecium, whereas the remaining 31 (5.2%) were fungi. Enterobacteriaceae resistance to carbapenems, piperacillin/tazobactam, cefoperazone sodium/sulbactam, and tigecycline were 11.0%, 15.3%, 15.4%, and 3.3%, with a descending trend year on year. Non-fermenters tolerated piperacillin/tazobactam, cefoperazone sodium/sulbactam, and quinolones at 29.6%, 13.3%, and 21.7%, respectively. However, only two gram-positive bacteria isolates were shown to be resistant to glycopeptide antibiotics. Conclusions: Bloodstream pathogens in hematological malignancies were broadly dispersed, most of which were gram-negative bacteria. Antibiotic resistance rates vary greatly between species. Our research serves as a valuable resource for the selection of empirical antibiotics.

Efficacy and safefy of Polymyxin B treatment for neutropenic patients suffering from refractory Gram-negative bacterial bloodstream infection / 中华血液学杂志

Objective: To assess the efficacy and safety of polymyxin B in neutropenic patients with hematologic disorders who had refractory gram-negative bacterial bloodstream infection. Methods: From August 2021 to July 2022, we retrospectively analyzed neutropenic patients with refractory gram-negative bacterial bloodstream infection who were treated with polymyxin B in the Department of Hematology of the First Affiliated Hospital of the Soochow University between August 2021 to July 2022. The cumulative response rate was then computed. Results: The study included 27 neutropenic patients with refractory gram-negative bacterial bloodstream infections. Polymyxin B therapy was effective in 22 of 27 patients. The median time between the onset of fever and the delivery of polymyxin B was 3 days [interquartile range (IQR) : 2-5]. The median duration of polymyxin B treatment was 7 days (IQR: 5-11). Polymyxin B therapy had a median antipyretic time of 37 h (IQR: 32-70). The incidence of acute renal dysfunction was 14.8% (four out of 27 cases), all classified as "injury" according to RIFLE criteria. The incidence of hyperpigmentation was 59.3%. Conclusion: Polymyxin B is a viable treatment option for granulocytopenia patients with refractory gram-negative bacterial bloodstream infections.