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Objective:To compare the laboratory diagnostic methods of Mycoplasma pneumonia(MP) and evaluate its clinical value.Methods:A prospective study.Throat swabs and double sera of children with MP infection were collected from December 2016 to January 2017 in Shengjing Hospital Affiliated to China Medical University; throat swab samples of healthy children aged 3 to 5 in Chaoyang District, Beijing were collected from March to May 2017.Passive agglutination (PA) was used to detect the double serum.Taking the 4-fold increase or decrease of the specific antibody titer of the double serum as the gold standard, the receiver operating characteristic curve (ROC) was drawn, and the laboratory methods for detecting MP infection were compared and evaluated.Results:(1)A total of 93 children with MP infection were clinically diagnosed, including 42 males (45.2%) and 51 females (54.8%), with an average age of 5.5 years.Sixty cases (64.5%) of MP infection were diagnosed.There were 349 healthy children, 198 males and 151 females, with an average age of 4.3 years.The positive rate of throat swab culture was 0.6% (2 cases), and the positive rate of fluorescent quantitative PCR(qPCR) was 18.9% (66 cases). (2) The culture specificity was the highest (100.0%) and the sensitivity was the lowest (65.0%). PA and enzyme linked immunosorbent assay (ELISA) were used to detect a single serum in the acute phase, the sensitivity was 71.7% and 86.5% respectively.ROC curve suggested that the current clinical diagnostic threshold MP specific antibody IgM ≥ 1∶160 was not the best diagnostic threshold.Molecular biological diagnostic methods were the most sensitive, RNA simultaneous and testing (SAT) was 85.0% and qPCR was 93.0%; while the specificity was low, 75.7% (SAT) and 63.6% (qPCR), respectively.(3) At the same time, MP nucleic acid (SAT, PCR) of throat swabs and a single serum (ELISA, PA) of children in acute phase were detected, the sensitivity was increased to 95.0%-100.0%, and the specificity was 63.6%-75.7%.Conclusions:Molecular biology is highly sensitive in diagnosing MP infection.It has asymptomatic infection or is carried after infection.Whether it needs treatment needs to be combined with clinical practice, when MP detection is positive.The detection of a single serum in the acute phase with a course of about 1 week has high sensitivity and is of reference value for the diagnosis of MP infection, but the diagnosis needs to be combined with clinical practice.The sensitivity and accuracy of detecting MP infection by single serological test combined with SAT in acute phase are higher than that by single application.
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Objective To investigate the antibacterial effect of Fusidic acid on Mycoplasma pneumoniae and antibiotic resistant Mycoplasma pneumoniae in vitro.Methods Twenty-eight clinical strains of Mycoplasma pneumoniae isolated from patients with respiratory tract infection at Beijing Friendship Hospital Affiliated to the Capital University of Medical Sciences from January to December 2016 and 2 Mycoplasma pneumoniae reference strains were enrolled.The minimum inhibitory concentration (MIC) of Fusidic acid and Azithromycin were determined by using micro-dilution ration method.The chessboard method was used to check the antibacterial effect of combination between Fusidic acid and Azithromycin.The antibacterial activity of the Fusidic acid was evaluated by measuring the antibacterial rate of different concentrations.Results One isolate showed no mutation in 23SrRNA,26 isolates had one point mutation in loci 2063 and 1 isolate had one point mutation in loci 2064 among the 28 clinical isolates.The findings by micro-dilution method results showed that the MIC values of all the clinical isolates with mutations associated with macrolide resistance to Azithromycin were ＞ 1.000 0 mg/L,and the MIC values of all the clinical isolates with no mutations to azithromycin were ＜ 0.500 0 mg/L.The findings by micro-dilution method results showed that the MIC value of Fusidic acid for Mycoplasma pneumonia and drug resistance Mycoplasma pneumoniae was 1.000 0 mg/L.The Fractional Inhibitory Concentration index of Fusidic acid and Azithromycin combination was ≤0.500 0 mg/L.When the concentration of the Fusidic acid was lower than or equal to 32 MIC,the antibacterial effect of Fusidic acid against Mycoplasma pneumoniae increased with its higher concentration.When the concentration of the Fusidic acid was lower than or equal to 8 MIC,the longer the strain was exposed to the drug,the stronger antibacterial effect was against Mycoplasma pneumoniae.Conclusion If the treatment of Mycoplasma pneumoniae infection is not effective or the infection of patient is combined with bacteria,the application or combination of Fusidic acid may inhibit pathogenic bacteria effectively.Of course,how to use Fusidic acid in clinical treatment needs further study and discussion.
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Objective To explore the clinical significance of the union between marrow smear and marrow biopsy in the myelodysplastic syndrome(MDS) diagnosis. Methods Bone marrow aspirate and smear were initially abtained, then bone tissues encircled drill and section at the same point which is called as. easy one-step technology to 86 MDS patients were analysed. Results In 86 cases of MDS patients, there were 30 cases of hyperplasia extreme degree of reduction by 34.88 %, 56 eases of active, obvious and extremely active active (65.12 %), 43 cases for red RCMD (50.00 %), 32 cases for the granulocyte dysplasia (37.21%), 22 cases for megakaryocyte RCMD (25.58 %) in bone marrow aspiration smears; compared with 15 cases of hyperplasia extreme degree of reduction and the reduction (17.44 %), 71 eases of active, obviously active and extremely active (82.56 %); 16 cases for red RCMD (18.61%), 52 cases for the granulocyte dysplasia (60.47 %), 56 cases for megakaryocyte RCMD (65.12 %) in bone marrow biopsy sections. 66 cases in 86 cases of bone marrow biopsy and bone marrow smear of WHO classification were in line with the rate of 76.74 %.Conclusion The biopsy slide and the puncture smear synchronization observation is more advantageous than the conventional puncture smear morphology observation and combining two method may increase the accuracy in the MDS diagnosis.