Objective To evaluate the basic performance and clinical application value of nanopore sequencing, in order to provide new ideas for the rapid detection of clinical etiology. Methods From December 2021 to May 2022, blood samples from inpatients suspected of bloodstream infection in Renmin Hospital of Wuhan University were collected, and the nanopore sequencing platform and blood culture method were used to simultaneously identify the pathogenic bacteria in the blood samples of the selected patients, and identify the pathogenic bacteria in the blood samples of the selected patients. The basic performance and clinical utility of nanopore sequencing were evaluated. Results A total of 251 patients were included, and 119 patients (47.4%) were found to have pathogens by nanopore sequencing, which was higher than that of 23 patients (9.2%) by blood culture (χ2=79.167, P<0.001). The results of the two methods are not consistent (kappa=0.052, P=0.175). Nanopore sequencing has a certain missed detection rate. In terms of the types of pathogenic bacteria detected, 47 bacteria and 15 fungi were detected by nanopore sequencing. Conclusion Compared with blood culture, nanopore sequencing has a higher detection rate and more types of pathogens. This technology has obvious advantages in the rapid diagnosis of bloodstream infection pathogens.
中心静脉置管是现代重症医学救治危重患者的常用方法, 目前应用十分广泛。尽管这些导管提供了必要的血管通路, 但也将患者置于局部和全身性感染并发症的危险之中, 增加了感染的发生率, 并使导管相关性血流感染( catheter-related bloodstream infections, CRBSI) 更为常见, 明显延长了ICU 住院时间并增加了医疗费用。本文就近年来CRBSI 的发病机制、微生物学、诊断及治疗, 尤其是如何根据病原体对CRBSI 进行治疗做一概述。
Objective To analyze the species distribution and resistance of the pathogens isolated fromblood cultures of the patients in intensive care unit ( ICU) , and provide a basis for prevention and control of bloodstream infections in critically ill patients. Methods The data of blood cultures of the patients in ICUduring January 2009 to December 2011 was investigated retrospectively.Results In the last 3 years, positive rate of blood cultures of ICU patients was 15. 4% , 15. 7% , and 17. 6% respectively. Among the isolates, Gram-positive bacteria were predominant ( 52. 3% ) , followed in order by gram-negative bacteria ( 33. 1% ) and fungi ( 14. 7% ) . Aerobe and facultative anaerobe were the predominant bacterial isolates ( 99. 7% ) . Enterococcus faeciumand Staphylococcus spp. were the most common gram-positive bacteria, and 4. 5% of E. faecium isolates were resistant to vancomycin. Rate of methicillin-resistance for S. aureus and S. epidermidis was 73. 5% and 93. 7% respectively. In terms of gram-negative bacteria, Acinetobacter calcoaceticus- A. baumannii complex were the leading species, 96. 9% of the isolates had multi-drug resistance and 14. 1% of the isolates had extra-drug resistance. Klebsiella pneumonia and Escherichia coli isolates were less frequently isolated and those producing extended spectrum beta-lactamases accou ted for 70. 3% and 80. 0% of the isolates respectively. Candida spp. was the most common fungi isolates ( 96. 7% )with an annual change of species distribution and declining susceptibility to azoles.Conclusions Gram-positive bacteria should be the major target for prevention and control of bloodstream infections in critically ill patients. Whereas, more attention should be paid to the infection caused by candida spp. and multidrug resistant gram-negative bacteria.
ObjectiveTo explore the prognostic risk factors for patients with gram positive coccus bloodstream infections. MethodsBy retrospective analysis, 93 patients with gram positive coccus bloodstream infections were recruited from the China-Japan Friendship Hospital during January 2013 to April 2015.According to the 28-day survival situation, the patients were divided into a survival group and a death group.The clinical data including basic diseases and invasive operation were collected.Logistic regression analysis was used to evaluate the risk factors for predicting prognosis. ResultsThe albumin concentration in the death group was lower than that in the survival group (P < 0.05).The D-Dimer concentration, APACHEⅡscores, the percentage of patients with mechanical ventilation, and the percentage of patients with deep venous cannels in the death group were all higher than those in the survival group (P < 0.05).The percentages with diabetes mellitus, surgery, tumor, renal failure in the patients with enterococcus bloodstream infections were much higher than those patients with other gram positive coccus bloodstream infections (P < 0.05), but were not different with those patients with Staphylococcus aureus bloodstream infection (P > 0.05).The APACHEⅡscore and albumin concentration had statistical significance for predicting the 28-day and 90-day mortality.The area under the receiver operating characteristic (ROC) curve was 0.768 and 0.775.If using APACHEⅡscore > 22.5 as cut off value for predicting death in 28 days, the sensitivity was 70.0%, and the specificity was 81.2%.If Using albumin concentration < 32.5 g/L as a cutoff value for predicting death in 28 days, the sensitivity was 55.3%, and the specificity was 86.7%. The logistic multifactor analysis revealed only the lower albumin concentration was an independent prognostic factor for 28-day mortality of the patients with gram positive coccus bloodstream infections (P < 0.05). ConclusionsThe patients with diabetes mellitus, surgery, tumor, and renal failure need to be cautious of enterococcus bloodstream infection.The low albumin concentration suggests a poor prognosis in patients with gram positive coccus bloodstream infections.
Objective To investigate the predictors for carbapenem-resistant Acinetobacter baumannii, Enterobacteriaceae and Pseudomonas aeruginosa (CR-AEP) as the pathogens of bloodstream infection (BSI) for intensive care unit (ICU) patients. Methods A retrospective case-control study based on ICU- healthcare-associated infection (HAI) research database was carried out. The patients who have been admitted to the central ICU between 2015 and 2019 in the ICU-HAI research database of West China Hospital of Sichuan University were selected. The included patients were divided into two groups, of which the patients with ICU-acquired BSI due to CR-AEP were the case group and the patients with BSI due to the pathogens other than CR-AEP were the control group. The clinical features of the two groups of patients were compared. Logistic regression model was used to identify the predictors of BSI due to CR-AEP.ResultsA total of 197 patients with BSI were included, including 83 cases in the case group and 114 cases in the control group. A total of 214 strains of pathogenic bacteria were isolated from the 197 BSI cases, including 86 CR-AEP strains. The results of multivariate logistic regression analysis showed that previous use of tigecycline [odds ratio (OR)=2.490, 95% confidence interval (CI) (1.141, 5.436), P=0.022] was associated with higher possibility for CR-AEP as the pathogens of BSI in ICU patients with BSI, while previous use of antipseudomonal penicillin [OR=0.497, 95%CI (0.256, 0.964), P=0.039] was associated with lower possibility for that. Conclusion Previous use of tigecycline or antipseudomonal penicillin is the predictor for CR-AEP as the pathogens of BSI in ICU patients with BSI.
Objective To investigate the species distribution and antibiotic resistance of pathogens fromcatheter-related bloodstream infections ( CRBSI) in intensive care unit( ICU) , to provide evidence for the guidance of clinical rational administration.Methods A retrospective analysis was performed to review the microbiological and susceptibility test data of all CRBSI patients in ICU from January 2009 to December 2011. The patterns of antibiotic resistance among the top seven bacteria were compared. Results 67 cases of CRBSI were detected with 81 strains, including 40 Gram-positive ( G+ ) bacteria( 49.4% ) , 38 Gram-negative( G- ) bacteria ( 46.9% ) , and 3 fungi ( 3.7% ) . The main pathogens causing CRBSI were coagulase negative Staphylococci ( 27 strains, 33.3%) , Acinetobacter baumannii ( 12 strains, 14.8% ) , Klebsiella pneumoniae( 9 strains, 11. 1% ) , Staphylococcus aureus ( 8 strains, 9. 9% ) , Pseudomonas aeruginosa ( 7 strains, 8. 6% ) , Escherichia coli ( 6 strains, 7.4% ) , suggesting that Staphylococcus epidermidis was predominant pathogenic G+ bacteria, and Acinetobacter baumannii was predominant G- bacteria. The antibiotic resistance tests demonstrated that isolated G- bacillus was highly sensitive to carbopenem, while vancomycin-resistant G+ bacteria were not found. Conclusions Within the latest 3 years, the predominant pathogens of CRBSI in ICU are Staphylococcus epidermidis and Acinetobacter baumannii. Acinetobacter baumannii exhibited high drug resistance to all antibiotics.
Objective To investigate the species distribution and antibiotic resistance among the bloodstream infections in intensive care unit ( ICU) . Methods A retrospective analysis was performed to review the microbiological and susceptibility test data of all bloodstream infections in ICU from January 2004 to September 2009. The patterns of antibiotic resistance among the top five bacteria were compared. Results 89 cases of bloodstream infection were detected with 112 strains, including 55 Gram-positive ( G+ ) bacteria( 49. 1% ) , 55 Gram-negative ( G- ) bacteria ( 49. 1% ) , and 2 fungi ( 1. 8% ) . The main pathogens causing bloodstream infection were Burkholderia spp. ( 33, 29. 5% ) , S. epidermidis( 31, 27. 7% ) , Klebsiella pneumoniae ( 7, 6. 3% ) , S. aureus ( 7, 6. 3% ) , S. hominis ( 6, 5. 4% ) , Acinetobacter baumannii ( 6,5. 4% ) , Pseudomonas aeruginosa( 5, 4. 5% ) and S. haemolyticus( 5, 4. 5%) , suggesting that Burkholderia spp. was predominant pathogenic G- bacteria, and coagulase-negative staphylococcus was predominant G+ bacteria. The antibiotic resistance tests demonstrated that isolated G- bacillus was highly sensitive to carbopenem, while vancomycin-resistant G+ cocci were not found. Conclusions Within the latest 5 years,the prevalence of G+ bacteria infection is almost equivalent to G- bacteria in blood stream infection.Coagulase-negative staphylococcus is the mainly G+ bacteria and Burkholderia spp. is predominant in G- bacteria. Carbopenemand glycopeptides still remain to be the first choice.