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 characteristics of the pathogens causing bloodstream infection after general surgery in infant and young children patients, and to provide the references for disease treatment and nosocomial infection control. Methods The clinical and laboratory examination data after general surgery in infant and young children patients, who were admitted to our hospital from January 2012 to March 2017, were retrospectively collected. The pathogens and drug resistance were analyzed by SPSS 18.0 software. Results In this study, 109 cases were included, and 117 strains of the pathogens were isolated, including 53 isolates (45.3%) of gram negative bacteria, 41 isolates (35.0%) of gram positive bacteria, and 23 isolates (19.7%) of fungi. Escherichia coli (16/117, 13.7%), Enterococcus faecium (13/117, 11.1%), Candida parapsilosis (12/117, 10.3%), Klebsiella pneumoniae (9/117, 7.7%) and Enterococcus faecalis (8/117, 6.8%) were the top 5 species. Strains producing extended-spectrum beta-lactamase accounted for 87.5% of E. coli (14/16) and 44.4% (4/9) of K. pneumoniae isolates. Both E. faecium and E. faecalis were susceptible to vancomycin. C. parapsilosis showed the susceptibility to the antifungal agents. Conclusion Gram negative bacteria are predominant pathogens causing bloodstream infection after general surgery in infant and young children patients, and infection caused by resistant isolates should be prevented and controlled.
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.
Objective To investigate the clinical characteristics and bacterial drug resistance of bloodstream infection of gram-negative bacteria, and provide guidance for clinical rational drug use and control of hospital infection. Methods A retrospective analysis was conducted in the patients diagnosed as severe pneumonia with blood culture of gram-negative bacteria from January 2015 to December 2017 in Beijing Anzhen Hospital. Results A total of 60 severe pneumonia patients suffered from bloodstream infection of gram-negative bacteria were recruited including 34 males and 26 females aging from 42 to 89 years and 73.4 years in average. In the 60 patients, 32 cases were infected with Klebsiella pneumonias, 20 cases were infected with Acinetobacter baumanni, and 8 cases were infected with Escherichia coli. The antimicrobial susceptibility testing result of Klebsiella pneumonias showed that the drug susceptibility rate was 100% to tigecycline, and 6.3% to amikacin. Escherichia coli was sensitive to Amikacin, imipenem, ceftazidime and meropenem while resistance to other drugs. The antimicrobial resistance of Acinetobacter baumanni was 28.6% for cefoperazone/sulbactam, and 14.3% for tigecycline. C-reactive protein, procalcitonin and SOFA scores were higher in the patients infected with Acinetobacter baumanni. Neutrophils and blood lactic acid were higher in the patients infected with Klebsiella pneumonias. There were no statistical differences in white blood cell, platelet or motality rate between the patients infected with Acinetobacter baumanni and the patients infected with Klebsiella pneumonias. SOFA scores and blood lactic acid had significantly statistical relevance with prognosis. Conclusion There is a high proportion of drug resistance of Klebsiella pneumoniae and Acinetobacter baumanni in the bloodstream infection of gram-negative bacteria.
Objective To review the clinical features and trend in antimicrobial resistance of Acinetobacter baumannii (A. baumannii) bloodstream infections. Methods Retrospective analysis was performed by collecting data of underlying diseases, potential risk factors, clinical characteristics, blood test results, Acute Physiology and Chronic Health EvaluationⅡ (APACHEⅡ) scores at onset, bacterial resistance to antibiotics and antimicrobial therapy were collected in Hunan Provincial People’s Hospital from January 2010 to June 2016. Results There were 114 non-duplicated A. baumannii complex blood isolates identified in this research. All patients had at least one underlying disease and accepted at least one surgery or invasive operation within the past 14 days. Multidrug-resistant A. baumannii (MDRAB) was isolated from 89 (78.1%) patients. Of the 114 strains of A. baumannii, 12.3% were resistant to tigecycline, 55.3% to amikacin and 61.4% to cefoperazone-sulbactam. The overall mortality was 51.8% (59/114). The patients with MDRAB had higher mortality rate than those with non-MDRAB (62.9% vs. 12.0%, χ2=20.268, P<0.001). With higher incidence of being in the intensive care unit, intubation/tracheotomy and increased APACHEⅡ score among patients with MDRAB bacteremia (P<0.05). Compared with subjects treated with tigecycline based regimen, those treated with non tigecycline for multidrug resistantA. baumannii had a higher mortality (64.8% vs. 60.0%) but there was no statistical significance (P>0.05). Conclusions The isolated A. baumannii are mainly multidrug resistant and with high mortality. Being in the intensive care unit, increased APACHEⅡ score and intubation/tracheotomy were risk factors for higher mortality among patients with MDRAB bloodstream infection. Tigecycline based regimen doesn’t improve patients’ prognosis.
ObjectiveTo explore the prognostic risk factors of bloodstream infections caused by Acinetobacter baumannii in the hospital, to provide a basis for clinical diagnosis and treatment.MethodsA retrospective analysis was performed on the medical records of patients diagnosed with Acinetobacter baumannii bloodstream infection in Guangxi Zhuang Autonomous Region People’s Hospital between January 2013 and December 2018. The patients were divided into survival group and non-survival group according to the outcome within 30 days after blood culture was collected. Univariate and multivariate logistic analyses were used to identify the risk factors of Acinetobacter baumannii bloodstream infections.ResultsA total of 123 patients were included, including 48 in the survival group and 75 in the non-survival group. Third generation cephalosporins [odds ratio (OR)=2.492, 95% confidence interval (CI) (2.125, 2.924), P<0.001], carbapenems [OR=1.721, 95%CI (1.505, 1.969), P<0.001], multidrug resistant-Acinetobacter baumannii infection [OR=1.240, 95%CI (1.063, 1.446), P=0.006], post-operation [OR=0.515, 95%CI (0.449, 0.590), P<0.001], mechanical ventilation [OR=1.182, 95%CI (1.005, 1.388), P=0.043], indwelling central venous catheter [OR=0.116, 95%CI (0.080, 0.169), P<0.001], mixed infection or septic shock [OR=3.935, 95%CI (2.740, 5.650), P<0.001], APACHE Ⅱ score (≥15) [OR=5.939, 95%CI (5.029, 7.013), P<0.001], chronic kidney disease [OR=1.440, 95%CI (1.247, 1.662), P<0.001], immune system disease [OR=28.620, 95%CI (17.087, 47.937), P<0.001], use of corticosteroids [OR=0.520, 95%CI (0.427, 0.635), P<0.001], and combined antifungal agents [OR=0.814, 95%CI (0.668, 0.992), P=0.041] were independent factors for predicting the prognosis of patients with bloodstream infections caused by Acinetobacter baumannii.ConclusionsThe third generation cephalosporins, carbapenem, MDR-Acinetobacter baumannii infection, post-operation, mechanical ventilation, indwelling central venous catheter, mixed infection or septic shock, APACHE Ⅱ score (≥15), chronic kidney disease, immune system disease, use of corticosteroids, and combined antifungal agents were independent factors for predicting the prognosis of patients with bloodstream infections caused by Acinetobacter baumannii. In the clinical work, it is needed to carry out timely detection of microbial etiology, timely report, and reasonable treatment.
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.