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 analyze the clinical characteristics, risk factors, and drug resistance of pathogenic bacteria in patients with blood stream infections (BSI) after orthopedic surgery, so as to provide reference and basis for clinical diagnosis and treatment.MethodsA retrospective analysis was made on the clinical data of 6 348 orthopedic patients admitted for surgery between January 2017 and December 2019. There were 3 598 males and 2 750 females. Their age ranged from 18 to 98 years, with an average of 66 years. The data of patients were collected, and the risk factors of BSI were analyzed by univariate analysis and logistic regression analysis. The distribution of BSI pathogenic bacteria, the results of drug sensitivity test, the incidence of BSI in patients after orthopedic surgery in different years, and the common sites of BSI secondary infection were summarized.ResultsBSI occurred in 106 (1.67%) of 6 348 patients after orthopedic surgery. There were 71 cases (66.98%) of secondary infection. The mortality of postoperative BSI patients was 1.89%, and the difference was significant when compared with that of non-postoperative BSI patients (0.24%) (χ2=5.313, P=0.021). The incidences of BSI in 2017, 2018, and 2019 were 1.18%, 1.53%, and 2.17%, respectively, showing an increasing trend year by year (trend χ2=6.610, P=0.037). Statistical analysis showed that the independent risk factors for BSI after orthopedic surgery (P<0.05) included the trauma, length of hospital stay≥14 days, emergency surgery, postoperative leukocyte counting<4×109/L, level of hemoglobin≤90 g/L, albumin≤30 g/L, the time of indwelling ureter>24 hours, use of deep vein catheter insertion, and merging other site infection. Blood culture showed 56 strains (52.83%) of Gram-positive bacteria, 47 strains (44.34%) of Gram-negative bacteria, and 3 strains (2.83%) of fungi. The top three pathogenic bacteria were coagulase negative Staphylococci (CNS; 36 strains, 33.96%), Escherichia coli (16 strains, 15.09%), and Staphylococcus aureus (15 strains, 14.15%). The detection rates of extended-spectum β-lactamases producing strains of Escherichia coli and Klebsiella pneumoniae were 56.25% (9/16) and 44.44% (4/9), respectively. The detection rates of methicillin-resistant strains in Staphylococcus aureus and CNS were 46.67% (7/15) and 72.22% (26/36), respectively.ConclusionPostoperative BSI in orthopedic patients is caused by multiple factors. Preventive measures should be taken according to related risk factors and perioperative risk assessment should be strengthened. Staphylococcus and Escherichia coli are the most common pathogenic bacteria in BSI after orthopedic surgery. The infection rate and drug-resistant bacteria are increasing year by year. Therefore, drug resistance monitoring should be strengthened.
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 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.
Objective
To analyze distribution and drug resistance of pathogens in bloodstream infection in Sichuan Antibiotic Resistance Monitoring Network in 2016, and to provide the basis for clinical rational use of antimicrobial drugs in Sichuan province.
Methods
A total of 14 543 strains of bacteria in bloodstream infection were collected from Sichuan Antibiotic Resistance Monitoring Network in 2016. Bacteria strains were identified to species, drug susceptibility test was performed by using the MIC and disc diffusion method (KB method). The results were interpreted according to the clinical laboratory standards institute CLSI 2016. Drug resistance was analyzed by using WHONET 5.6 software.
Results
Among the 14 543 strains of bacteria, Escherichia coli (34.5%), Klebsiella pneumoniae (10.7%), Staphylococcus epidermidis (10.2%), Staphylococcus aureus (7.2%), Staphylococcus hominis (6.0%) ranked the first five. Resistance rate to imipenem was 0.9% for Escherichia coli, resistance rate to imipenem was 2.4% for Klebsiella pneumoniae. No vancomycin-resistance and linezolid-resistance Staphylococcus epidermidis, Staphylococcus aureus and Staphylococcus hominis were found. MRSA detection rate was 25.8%.
Conclusion
Gram negative bacteria are the main pathogens in the blood cultures in Sichuan province, while attention should pay to the Staphylococcus.
Bloodstream infections are featured by acute onset, rapid progression and high mortality. Early identification and accurate prognostic assessment are crucial for improving patient outcomes. This article reviews five novel biomarkers in assessing the severity and prognosis of patients with acute bloodstream infection, namely soluble triggering receptor expressed on myeloid cell-1, soluble form of the urokinase plasminogen activator receptor, presepsin, heparin-binding protein and microRNAs, all of which are positively correlated with the severity of patients’ condition, and some perform better than traditional biomarkers. However, they still have limitations such as inadequate specificity or sensitivity and lack of large-scale verification. In the future, it is necessary to integrate molecular detection and artificial intelligence to optimize application strategies and provide personalized diagnosis and treatment.
