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.

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.

Evaluation of the combination treatments with intravenous fosfomycin for carbapenem-resistant Klebsiella pneumoniae

SUMMARY OBJECTIVE: The aim of this study was to evaluate the combination treatments with intravenous fosfomycin for carbapenem-resistant Klebsiella pneumoniae infections in a tertiary-care center. METHODS: Between December 24, 2018 and November 21, 2022, adult patients diagnosed with bloodstream infection or ventilator-associated pneumonia due to culture-confirmed carbapenem-resistant Klebsiella pneumoniae in the anesthesiology and reanimation intensive care units were investigated retrospectively. RESULTS: There were a total of 62 patients fulfilling the study inclusion criteria. No significant difference was recorded in 14- and 30-day mortality among different types of combination regimens such as fosfomycin plus one or two antibiotic combinations. Hypokalemia (OR:5.651, 95%CI 1.019-31.330, p=0.048) was found to be a significant risk factor for 14-day mortality, whereas SOFA score at the time of diagnosis (OR:1.497, 95%CI 1.103-2.032, p=0.010) and CVVHF treatment (OR:6.409, 95%CI 1.395-29.433, p=0.017) were associated with 30-day mortality in multivariate analysis. CONCLUSION: In our study, high mortality rates were found in patients with bloodstream infection or ventilator-associated pneumonia due to carbapenem-resistant Klebsiella pneumoniae, and no significant difference was recorded in 14- and 30-day mortality among different types of combination regimens such as fosfomycin plus one or two antibiotic combinations.

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.

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.

Screening and clinical significance of intestinal colonization of carbapenem-resistant Enterobacteriaceae (CRE) in patients before haploidentical hematopoietic stem cell transplantation / 中国输血杂志

【Objective】 To investigate the situation of carbapenem-resistant Enterobacteriaceae(CRE) colonization in patients undergoing haploidentical hematopoietic stem cell transplantation (haplo-HSCT). 【Methods】 A total of 241 consecutive patients who underwent haplo-HSCT in the First Affiliated Hospital of Soochow University from June 1, 2021 to June 1, 2022 were enrolled. Anal swab screening was performed within 48 hours of admission and blood cultures were taken when the patient developed fever. Univariate and multivariate analysis were used to analyze the colonization rate, distribution, risk factors and the correlation between CRE colonization and post-transplant bloodstream infection(BSI). 【Results】 Among 241 patients with haplo-HSCT, there were 90 cases in CRE colonization positive group, with a colonization rate of 37.3% (90/241). Multivariate logistic regression analysis showed that sex (OR 2.42, 95% CI 1.38-4.22, P<0.05) and history of infection within 30 days before transplantation (OR 3.37, 95% CI 1.59-7.17, P<0.05) may be independent risk factors for CRE intestinal colonization. Of the 95 CRE strains, the top five species were carbapenem-resistant Klebsiella pneumoniae (38/95, 40.0%), carbapenem-resistant Escherichia coli (29/95, 30.5%), carbapenem-resistant Enterobacter cloacae (13/95, 13.6%), carbapenem-resistant Klebsiella acidophilus (6/95, 6.3%) and carbapenem-resistant Proteus mirabilis (3/95, 3.1%). The incidence of post-transplant BSI was 12.0% (29/241) in the CRE-colonized group and 3.3% (8/241) in the non-colonized group. In the colonization group, 100% of the pathogens of BSI were identical with those of CRE colonization. 【Conclusion】 Bacterial culture of anal swab during haplo-HSCT is helpful for detection of CRE colonization in intestinal tract, which provides some clinical basis for active monitoring of key flora, prevention and control of infection.

Clinical outcomes and early immune reconstitution in patients with acute lymphoblastic leukemia underwent allogeneic hematopoietic stem cell transplantation / 中国输血杂志

【Objective】 To investigate the correlation between early immune reconstitution and clinical outcomes in patients with acute lymphoblastic leukemia (ALL) underwent allogeneic hematopoietic stem cell transplantation (allo-HSCT). 【Methods】 The basic information and treatment data of 99 patients with ALL undering allo-HSCT from December 2018 to February 2022 were collected. The proportions of CD3+ T, CD3+CD4+ T, CD3+CD8+ T and CD3-CD16+CD56+ NK cells were detected before and 30, 60 and 90 days after transplantation using flow cytometry. The correlation between early cellular immune reconstitution and neutrophil engraftment, platelet engraftment, infection, and acute and chronic graft-versus-host disease (GVHD) was analyzed. 【Results】 Among 99 ALL patients, the median time of neutrophil engraftment was day +11 (range, 8-28), and the median time of platelet engraftment was day +14 (range, 10-120). The cumulative incidence of blood stream infection (BSI) was 11.10% and the cumulative incidence of CMV within 100 days of transplantation was 40.40%. The cumulative incidence of EBV within 100 days was 7.10%. The cumulative incidence of acute graft-versus-host disease (aGVHD) was 22.30%. The cumulative incidence of chronic graft-versus-host disease (cGVHD) within 1 year of transplantation was 16.20%. 1 -year cumulative relapse rate was 13.84%. The 1 -year cumulative disease-free survival (DFS) for all patients was 80.60% and the 1-year overall survival (OS) was 90.30%. The CD4+/CD8+ ratio was positively associated with the development of aGVHD at 30 days post-transplant (OR 1.21, 95CI 1.01-1.45, P<0.05). The proportion of CD16+ CD56+ NK cell were higher in the group without BSI than that in the BSI group before and 30 days after transplantation (P < 0.05). The proportion of CD4+ T-cell were lower in the CMV infection group than that in the group without CMV infection at 60 and 90 days post-transplant(P<0.05). The higher level of CD4+ T-cells at 60 days post-transplant was a protective factor for CMV infection within 100 days (HR 0.91, 95CI 0.84-0.99, P<0.05). 【Conclusion】 Early immune reconstitution after allo-HSCT in patients with ALL is associated with aGVHD, CMV and BSI.

Isolation and identification of Balneatrix alpica from patient′s blood and hot spring water / 中华微生物学和免疫学杂志

Objective:To identify and characterize two Balneatrix alpica strains isolated from a patient′s blood sample (strain X117) and the natural hot spring water in the patient′s residential district (strain GN-1), and to provide experimental evidence for the pathogenic diagnosis of clinical infection caused by this rare pathogen. Methods:Biochemical phenotypic identification, matrix-assisted laser desorption ionization time-of-flight mass spectrometry (MALDI-TOF MS), 16S rRNA gene sequencing, phylogenetic analysis, single-nucleotide polymorphism (SNP) analysis, and genome-wide analysis were performed to accurately determine the taxonomic status of the isolates X117 and GN-1 by using Balneatrix alpica DSM 16621 T as a reference. Microdilution broth method was used to test their antimicrobial susceptibility. The virulence genes carried by them were annotated and analyzed using the virulence factor database (VFDB). Results:Strains X117 and GN-1 formed light yellow or tan colonies with mottled surfaces on Columbia blood agar and chocolate agar plates after 4 d of culture. They were Gram-negative rods and positive for oxidase and indole tests, which were consistent with the characteristics of Balneatrix alpica DSM 16621 T. The phylogenetic analysis based on the 16S rRNA gene showed that the isolates X117 and GN-1 were both Balneatrix alpaca. The average nucleotide identity (ANI) values between the two isolates and Balneatrix alpica DSM 16621 T were 98.44% and 98.41%, respectively, and the digital DNA-DNA hybridization (dDDH) values were both 87.1%. The SNP distance between the two strains was 13, indicating that X117 and GN-1 might belong to the same clone. The antibiotic susceptibility testing showed that all of the three Balneatrix alpica strains were sensitive to the commonly used antibiotics against Gram-negative rods. The virulence genes carried by the three Balneatrix alpica strains were mainly involved in adhesion, invasion, flagella and biofilm formation. Conclusions:This study identified a case of bloodstream infection caused by Balneatrix alpica which was closely related to natural hot spring water. Natural hot spring water migh be an important source of clinical infections caused by this species.

Diagnosis of community-acquired bloodstream infection in the elderly at primary care / 中华全科医师杂志

Bloodstream infection (BSI) is a serious clinical condition with high fatality rate. The elderly patients account for a large proportion of community-acquired BSI cases, and general practitioners should play an important role in early identification and diagnosis of community elderly BSI patients. This article reviews the status quo of diagnosis of community-acquired BSI in the elderly. Based on clinical manifestations, accessible biomarkers and blood cultures, general practitioners can make an early diagnosis and timely transfer the patients to reduce the fatality rate of community-acquired BSI.

Comparison of monitoring systems for central line-associated blood stream infections (CLABSI) between China and the United States / 中华临床感染病杂志

Catheter-associated bloodstream infection(CRBSI) is one of the most common hospital-associated infections, and the incidence of central line-associated blood stream Infections (CLABSI) is the highest in CRBSI. This paper analyzes the current monitoring system of CLABSI in China, and compares the concept and method of National Healthcare Safety Network (NHSN) monitoring system, in order to make suggestions for the CLABSI monitoring system in China, and further improve the quality of medical safety.

Risk factors of mortality in Klebsiella pneumoniae bloodstream infection and construction of a prediction model for prognosis of patients / 中华临床感染病杂志

Objective:To explore the risk factors of mortality in patients with Klebsiella pneumoniae bloodstream infection, and to construct a predictive model. Methods:The clinical data of 234 patients with Klebsiella pneumoniae bloodstream infection admitted in the First Hospital of Qinhuangdao from January 2020 to December 2022 were retrospectively analyzed, including 202 cases admitted during January 2020 to June 2022 (model set), and 32 cases admitted during July to December 2022 (validation set). There were 64 cases died (fatal group) and 138 cases survived (survival group) within 28 d after admission in model set. Multivariate Logistic regression was used to analyze the risk factors of death in patients with Klebsiella pneumoniae bloodstream infection and a mortality prediction model was constructed. The constructed model was applied in validation set, and the consistency between predicted mortality and real mortality was analyzed. Results:Multivariate Logistic regression analysis showed that male sex ( OR=2.598, 95% CI 1.179-5.725, P=0.018), age≥65 years ( OR=4.420, 95% CI 2.029-9.627, P<0.001), admitted to intensive care unit (ICU) ( OR=10.299, 95% CI 4.752-22.321, P<0.001), and the empirical use of quinolones antibiotics ( OR=4.288, 95% CI 1.127-16.317, P=0.033) were independent risk factors for 28-day mortality in Klebsiella pneumoniae bloodstream infection patients. The regression equation for predicting the risk of death was -3.469+ male × 0.955+ age ≥ 65 years × 1.486+ admitted to ICU × 2.332+ empirical use of quinolone antibiotics × 1.456. The area under the ROC curve (AUC) for predicting death in the model set was 0.831, with sensitivity and specificity of 71.9% and 80.4%, respectively. The AUC for predicting death in the validation set was 0.881, with sensitivity and specificity of 91.7% and 75.0%, respectively. Conclusion:The constructed mortality prediction model in the study has good application value for the prognosis of patients with Klebsiella pneumoniae bloodstream infection.

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.

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 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.

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.

Epidemiological characteristics and influencing factors of nosocomial Escherichia coli infection in children / 公共卫生与预防医学

Objective To analyze the epidemiological characteristics of nosocomial Escherichia coli infection and risk factors of ESBLs-producing Escherichia coli infection in children, and to provide scientific basis for better prevention of nosocomial Escherichia coli infection in children. Methods A total of 169 children with nosocomial infection hospitalized in Handan Regional Children's Hospital from January 2020 to December 2020 were selected by random sampling method. After specimen collection, bacteria were identified by VitEK-32 identification system , and drug sensitivity of isolated pure Escherichia coli colony was identified by automatic drug sensitivity analyzer Phoenix 100. Statistical analysis of drug resistance of Escherichia coli. The clinical data of the children were retrieved from the case system by uniformly trained professionals, and the department distribution, underlying diseases, clinical characteristics, antibiotic resistance, length of hospital stay, surgery, invasive exercises and other clinical data of all the children were counted. Factor logistic regression analysis of the risk factors of nosocomial infection of ESBLs Escherichia coli in children in the hospital. Results A among of 39 strains of Escherichia coli were detected in children with nosocomial infection in children's hospital. The main specimens were 22 strains (56.41%) in sputum, 11 strains (28.21%) in urine and 6 strains (15.38%) in blood.Twenty-one strains of ESBLs Escherichia coli were detected, with a positive rate of 53.85%. Fever was the most common first symptom in 37 cases (94.87%). Children with ESBLs (+) Escherichia coli infection were significantly higher than those with ESBLs (-) Escherichia coli in age, length of hospitalization, neonates/recent use of broad-spectrum antibiotics, complicated underlying diseases, and invasive operation (P<0.05). Multivariate logistic regression analysis showed that recent use of antibiotics, combined with underlying diseases, and invasive operation were independent risk factors for ESBLs infection in children in hospital (P<0.05). Conclusion The incidence of nosocomial Escherichia coli infection in children is high, and active intervention should be carried out for children who have recently used antibiotics, complicated with underlying diseases, and invasive operations to reduce the risk of ESBLs Escherichia coli infection.

The value of immediate bedside blood cultures in the adjustment of antibiotics for children with bloodstream infections in PICU / 中国小儿急救医学

Objective:To explore the value of immediate bedside blood culture in the adjustment of antibiotics for children with bloodstream infections in pediatric intensive care units(PICU).Methods:Retrospective analysis of children in PICU at Henan Children′s Hospital from May 2017 to March 2021 was conducted.The cases were divided into laboratory blood culture(LBC) group and satellite blood culture(SBC) group according to different blood culture methods.The difference in the time to blood culture incubation, time to blood culture positivity, microbial results time and antibiotic adjustment time were compared between two groups.Results:A total of 3 720 blood cultures were completed in 2 718 children, including 1 888 in LBC group and 1 832 in SBC group, with a positive rate of 3.5% in LBC group and 4.9% in SBC group, and a significantly higher positive rate in SBC group compared to LBC group( χ2=3.954, P=0.046). The differences in age, sex, site of infection, survival rate at 28 d after discharge, pediatric critical illness score, and pediatric risk of mortality Ⅲ score between LBC group and SBC group with positive blood cultures were not statistically significant ( P>0.05). Children in SBC group had significantly shorter specimen receipt time, time to obtain microbiological results, and antibiotic adjustment time than those in LBC group[0.33(0.03, 1.78) h vs. 3.38(1.38, 7.29) h, (57.40±21.92) h vs. (68.14±21.26) h, and (52.53±27.23) h vs. (66.41±28.57) h, all P<0.05]. Conclusion:Immediate bedside blood culture shortens the time from culture to final result reporting, increases the positive rate of blood culture, and saves time on accurate antibiotic treatment for critically ill children.

Prognostic value of Pitt bacteremia score in patients with extensively drug-resistant Klebsiella pneumoniae bloodstream infection / 中华急诊医学杂志

Objective:To investigate the predictive value of Pitt bacteremia score (PBS) on 28-day mortality of patients with extensively drug-resistant Klebsiella pneumoniae (XDR-KP) bloodstream infection.Methods:A retrospective cohort study was conducted to analyze the clinical characteristics of patients with XDR-KP bloodstream infection admitted to the Emergency Intensive Care Unit of Nanjing Drum Tower Hospital from January, 2018, to December, 2021. The patients were divided into the survival and non-survival groups according to the 28-day survival. Multivariate logistic regression analysis was performed to determine the risk factors of 28-day mortality of the patients. Receiver operating curve (ROC) curve was drawn to analyze the predictive value of PBS in 28-day mortality of patients with XDR-KP bloodstream infection. The correlations between PBS, and acute physiology and chronic health evaluation II (APACHE II) and sequential organ failure (SOFA) assessment were performed using Pearson correlation coefficient. The optimal cut-off value of PBS score was used as the boundary point to group the differences between APACHE II and SOFA scores in different groups. Kaplan-Meier method was used to analyze the prognosis of patients with XDR-KP bloodstream infection.Results:A total of 118 patients (82 males and 36 females) with XDR-KP bloodstream infection, aged (65.98±15.16) years, were included in this study. The 28-day mortality was 61.02%. The PBS was significant higher in the non-survival group than in the survival group [(5.68±1.86) vs. (2.48±1.02), P=0.011]. Multivariate logistic regression analysis showed that PBS ( OR=4.940, 95% CI: 2.720-8.968, P=0.008), APACHE II score ( OR=1.630, 95% CI: 1.361-1.952, P=0.010) and SOFA score ( OR=1.879, 95% CI: 1.451-2.422, P=0.009) were independently risk factors of 28-day mortality of patients with XDR-KP bloodstream infection. The area under the ROC curve of the PBS predicting 28-day mortality was 0.970 (95% CI: 0.945-0.995, P<0.001), and the optimal cut-of value was 3.5. In addition, PBS was significantly associated with APACHE II score ( r=0.916, P<0.001) and SOFA score ( r=0.829, P<0.001). Moreover, Kaplan-Meier analysis showed that the 28-day survival rate of patients with PBS <3.5 was significantly higher than that of patients with PBS >3.5 ( P=0.001). Conclusions:PBS is a significant, independent predictor of 28-day mortality in patients with XDR-KP bloodstream infection.

Distribution of pathogenic bacteria of bloodstream infection after chemotherapy in patients with acute leukemia and risk factors analysis of the occurrence of adverse events and prediction model construction / 白血病·淋巴瘤

Objective:To investigate the distribution of pathogenic bacteria of bloodstream infection after chemotherapy in patients with acute leukemia (AL), to analyze the risk factors for the occurrence of adverse events and to construct a nomogram model to predict the occurrence of adverse events.Methods:The clinical data of 313 AL patients with bloodstream infection who were admitted to the First Hospital of Jilin University from January 2018 to December 2020 were retrospectively analyzed, and the incidence, fatality and distribution characteristics of pathogenic bacteria after chemotherapy in AL patients were analyzed; the occurrence of adverse events (death or infectious shock) in patients with different clinicopathological characteristics were compared. Unconditional logistic binary regression model multifactor analysis was used to screen independent risk factors for the occurrence of adverse events in AL patients with bloodstream infection after chemotherapy; the nomogram model for predicting the occurrence of adverse events was developed by using R software; the Hosmer-Lemeshow test was used to verify the predictive effect of the model.Results:Of the 313 AL patients, the overall fatality rate was 4.2% (13/313), the all-cause fatality rate of bloodstream infection was 3.5% (11/313). Of the 313 cases, 254 cases (81.1%) were Gram-negative bacteria infection, mainly including 115 cases (45.3%) of Escherichia coli, 80 cases (31.5%) of Klebsiella pneumoniae, and 29 cases (11.4%) of Pseudomonas aeruginosa, and 10 cases (3.9%) died; 51 cases (16.3%) were Gram-positive cocci infection, mainly including 22 cases (43.1%) of Streptococcus spp., 20 cases (39.2%) of Staphylococcus spp., 7 cases (13.7%) of Enterococcus faecalis, and 0 case died; 8 cases (2.6%) were fungal infection, including 4 cases (1.3%) of Candida tropicalis, 2 cases (0.6%) of Candida subsmoothis, 1 case (0.3%) of Candida smooth, 1 case (0.3%) of new Cryptococcus, and 3 cases (37.5%) died. The differences in the occurrence rates of adverse events were statistically significant when comparing different treatment stage, risk stratification, timing of sensitive antibiotic use, total duration of fever, and glucocorticoid use in chemotherapy regimen, infecting bacteria carbapenem resistance, and leukemia remission (all P < 0.05). The results of logistic binary regression analysis showed that the use of glucocorticoid in chemotherapy regimen, the total duration of fever ≥7 d, the timing of sensitive antibiotic use ≥24 h, and carbapenem resistance of the infecting bacteria were independent risk factors for the occurrence of adverse events in AL patients with bloodstream infection after chemotherapy (all P < 0.05). A nomogram prediction model for the occurrence of adverse events in AL patients with bloodstream infection was established, and the nomogram model was calibrated and validated with good calibration and discrimination. Conclusions:The pathogenic bacteria of bloodstream infection after chemotherapy in AL patients is mainly Gram-negative bacteria, and the presence of glucocorticoid in chemotherapy regimen, long total duration of fever, poor timing of sensitive antibiotics, and infecting bacteria carbapenem resistance are risk factors for the occurrence of adverse events in AL patients with bloodstream infection after chemotherapy, and the nomogram prediction model based on these factors has a reliable predictive ability for the occurrence of adverse events.

Clinical observation of polymyxin B in the treatment of CRKP-BSI in patients with hematological malignancies / 中国药房

OBJECTIVE To analyze the efficacy and safety of polymyxin B in the treatment of carbapenem-resistant Klebsiella pneumoniae （CRKP）-bloodstream infection （BSI） in patients with hematologic malignancies. METHODS The medical records of patients with hematologic malignancies with CRKP-BSI who received polymyxin B for at least 3 days in our hospital from September 2019 to June 2021 were retrospectively analyzed. All patients were initially treated with a triple therapy namely polymyxin B+tigecycline+carbapenems for anti-infection therapy. RESULTS A total of 10 patients were enrolled as the study subjects. Eleven strains of CRKP were cultured in blood， including 10 strains of CRKP produced Klebsiella pneumoniae carbapenemase（KPC） and 1 strain of CRKP produced both KPC and metal-beta-lactamase； 9 strains were sensitive to colistin， 7 strains were sensitive to tigecycline， 5 strains were sensitive to amikacin and 2 strains were sensitive to compound sulfamethoxazole. All patients were accompanied by neutropenia， with an average duration of （14.1±6.4） days. They were all characterized by fever， chills and fatigue. After treatment， 6 patients were cured and discharged， 4 patients died of ineffective treatment of septic shock. No serious adverse events related to polymyxin B occurred in all patients. CONCLUSIONS Polymyxin B can be used as a therapeutic drug for CRKP-BSI in patients with hematological malignancies. No serious adverse event related to polymyxin B occurs during the treatment.