| Objectives1,According to the results of blood culture in hematological patients,analyzing the current pathology and drug resistance of bloodstream infection;2,Analyzing main gram-negative bacteria’s drug resistance rate and the changes ofdrug resistance in the past three years,providing the basis for empirical anti-infective treatment;3,Studying the differential diagnosis value of procalcitonin(PCT)in coagulase-negative staphylococcal(CNS)bloodstream infection(BSI)and contamination in hematology patients,so doctors can timely and correctly distinguish betweenCNS bloodstream infection and contamination,reducing the use of unnecessary antibiotics.MethodsRetrospectivelyanalyzing the results of blood culture of all hospitalized patients in the Department of Hematology,the First Affiliated Hospital of Soochow University,Suzhou,China and collecting the data of basic clinical characteristics,the source of the specimens,the results of bacterial susceptibility test and related laboratory tests of patients.According to the data,we can analyze main gram-negative bacteria’s drug resistance rate and the changes of drug resistance in the past three years,which provides the basis for empirical anti-infective treatment.The patients with coagulase-negative staphylococcal blood culture were divided into real bloodstream infection group and pollution group.The basic situation of the two groups was compared and analyzed by SPSS 21.0 software.The measurement data were tested by t test,and the count data weretested byχ2 test.The diagnostic value was evaluated by ROC curve.Main Results1,In this retrospective analysis,we collect a total of 10307 hospitalized patients in hematology department of the First Affiliated Hospital of Soochow University from January 2013 to December 2015.A total of 6309 samples of blood culture were collected and 664 strains were positive,the positive rate was 10.5%.The count of Gram-positive strains was 326,accounting for 49.1%.Most of them were coagulase-negative staphylococcus,Staphylococcus aureus accounts for only 1.8%;Gram-negative bacteria were detected in 306 cases,the top three were Escherichia coli,Klebsiellapneumonia,Pseudomonas aeruginosa.2,Gram-negative bacteria’s drug resistance rate of commonly used antibiotic: the highest rate of resistance to ampicillin,up to 98.2%,the resistance rate of cefazolin,cefuroxime,cefotaxime,ceftriaxone and cefoperazone was all more than 85%.For Ceftazidime,cefepime is more sensitive,the resistance rate is 48.5% and 40.9%.For the combination of β-lactamase complex preparations such as cefoperazone / sulbactam and piperacillin / tazobactam,the resistance rate is lower than cephalosporins’,29.5% and 33.0% respectively.The resistance rate to imipenem was 26.9%,the resistance rate to amikacin was 20.5 %,the lowest of all the commonly used antibiotics;3,Three-year drug resistance changes of the first threeGram-negative bacteria: the overall detection rate of Escherichia coli was increasing year by year.The resistance rate toamikacin increased from 10.5% in 2013 to 17.4% in 2015,and the resistance rate to imipenem decreased to 4.3% in 2015 compared with that in2014;Klebsiellapneumoniae’s resistance to 3,4-generation cephalosporins increased significantly,theresistance rate toceftazidimeincreased from 31.6% in 2013 to 70.4% in 2015,to cefepime from 21.1% in 2013 to 51.9% in 2015.Happily,it’s resistance rate to amikacin decreased,from 21.1% in 2013 to 11.1% in 2015;Although,Pseudomonas aeruginosa’sresistance rate of antibiotic decreased in these three years,but it’s resistance rate to imipenem is still up to 21.7% in 2015,we didn’t findcefepime-resistant and amikacin-resisitantPseudomonas aeruginosa from 2013 to 2015;4,Clinical significance of procalcitonin in the differentiation of blood stream infection caused by coagulase-negative staphylococcal and contamination: there is a difference between CNS bloodstream infection group andcontamination group in the heat peak,CRP levels and serum PCT levels by t test.The heat peak value,CRP,and PCT were higher than those in the pollution group.So we drew the ROC curve,the results showed that when the procalcitonin was 0.374 ng / mL,the Youden index is the largest,at this time,the area under the curve(AUC)was 0.830 ± 0.032(95% CI: 0.767 ~ 0.893,P <0.001),the sensitivity was 54.5% and the specificity was 94.4%.Conclusion1,The incidence of bloodstream infection in our department was about 5.7%,and the positive rate of blood culture was 10.5%.Gram-negative bacteria were mainly Escherichia coli(15.5%)and Klebsiellapneumoniae(10.5 %),Gram-positive bacteria were mainly Staphylococcus epidermidis(12.1%)and Staphylococcus aureus(10.9%).2,Most of the detective gram-negative bacteria’s resistance rate to carbapenem antibiotics is still lower than 30%,So carbapenem antibiotics are still the best choices to treat Gram-negative bacteria infectionexcept Acinetobacterbaumanniifor hematology patients.3,The first three detective Gram-negative bacteria were Escherichia coli,Klebsiellapneumoniaeand Pseudomonas aeruginosa.Among them,Escherichia coli has no significant changes in drug resistance in three years,which mildly increases in a small number of antibiotics;Klebsiellapneumoniae on the three or four generations of cephalosporin resistance rate increased significantly,especially for cefepimewhich is from 21.1% in 2013 up to 51.9% in 2015,and Pseudomonas aeruginosa’s resistance rate to common antibiotics is down significantly.4,Coagulase-negative staphylococci accounted for 75.6% of detective gram-positive bacteria,No vancomycin,linezolid and teicoplanin resistant strains.Staphylococcus aureus accounted for only 3.7% of positive bacteria,of which methicillin-resistant Staphylococcus aureus(MRSA)accounted for 33.3%.5,Procalcitonin(PCT)has a certain clinical value in the identification of infection or contamination of coagulase-negative staphylococcal(CNS),the cut-off value is 0.374 ng / mL,and its specificity is higher than C-reactive Protein(CRP),the current commonly used indicator. |
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