The Correlation Between Drug-Resistance And Clinical Treatment Of Mycoplasma Pneumoniae In Children

Object:To explore the effectiveness and safety of Azithromycinsequential therapy treat mycoplasma pneumoniae infection in children,andtest whether durg-resistance have correlation with indisciplinely usedAzithromycin.Method: According to MP antibody titers1:320for MP infection asstandard to clinical diagnosis MP-IgM positive. From March2011toFebruary2013, a total of792children(screened5-13years old) with upperrespiratory infection complicating cough or(and) fever who suspected MPinfected were recruited. Among of them431MP-IgM positive cases weresubjects.According to differences frequency of macrolide antibioticsapplication and frequency of MP infection in one year,431children withMP positive were divided into experimental group(n=217) and controlgroup(n=214). Patients in experimental group were preliminary screeningsubjects who without MP infection and macrolide antibiotics appliedhistory in half of a year. Patients in control group were repeated MPinfected and indisciplinely used of macrolide antibiotics≥2times in oneyear. MP cultures of children in both groups were detected twice timeswhen they admitted. If their culture MP positive，23S rRNA V PCR productwere synthesis，and drug sensitivity test to9kinds of antibiotics weredetected. Compered the two groups diference in drug resistantrate.Children in experimental group whose positive culture MPantibiotics sensitivity and23S rRNA V had no mutation were gavemacrolides sequential therapy. In the end of2and4weeks aftermacrolides sequential therapy，detection MP cuture again. If their culture MP positive，analysed drug sensitivity and screened the23S rRNA Vmutation or not. At those two time points, the curative effects ofazithromycin sequential therapy were judged. Analysed whether it hadcorrelation between frequency of macrolide antibiotics irregularapplication and drug resistance rate in control group. Extra pulmonarycomplication and hospitalization time between two groups were analysisby statistics methods. The study protocol was approved by the EthicalReview Board of Investigation in Human Being of Guangdong Women andChildren Hospital Affiliated Guangzhou Medical University. Informedconsent was obtained from the parents of each participating participant.Result:1、MP-IgM test result：792suspected MP infection patients,MP antibody titer of1:320was431cases,the MP infection was54.4%。2、MP culture and drug sensitivity test results:Application MP rapid culture to431cases MP-IgM positive samples,105cases cultured positive,the positive rate24.36%。The experimental groupconsisted of56patients with MP culture postivie,among of them drugsusceptibility test of macrolide susceptible to25cases(44.6%) and31cases(55.4%) resistance。But49case in control group drug susceptibilitytest of macrolide susceptible12cases(22.5%) and37cases(75.5%)resistance.(In the drug-resistance strains22cases indisciplinely usedAzithromycin4times,13cases of3times,2cases of2times in one year)。The experimental group and control group had significant difference indrug resistant rate.The drug resistant rate and the irregular applicationof macrolide antibiotics had satistically significant relationship（χ2/χ2趋势=22.056/21.932，p<0.05）.The drug test have difference in twogroup and the total drug resistance rate was64.76%(68/105)。After2weeks Azithromycin Sequential treatment in experimental group,4cases MPculture were positive,but the drug test were sensitive。After4weeksAzithromycin Sequential treatment in experimental group,only1case MPculture was positive, the drug test also sensitive。3、23S rRNA V zone sequencing resultsFound on25cases in experimental group for MP drug sensitive strainsfor23S rRNA V region,14cases showed no mutation.After AzithromycinSequential Therapy2and4weeks,MP culture positive strain23S rRNA Vregion also had no mutation.other11samples without results.But incontrol group37cases had different gene mutation in23S rRNA V region.4、 Treatment resultsAfter2weeks Azithromycin Sequential Therapy in experimentalgroup,the cure rate was71.42%(10/14)。At the end of AzithromycinSequential Therapy,the cure rate was92.85%(13/14)。1case liver enzymeselevated in experimental group,but after Azithromycin Sequential Therapythe liver enzymes was normal.Follow up2weeks,the experimental grouphad no discomfort performance.16cases had Extrapulmonary complicationin control group(3cases myocardial injury,1cases Kawasaki disease,7cases with abdominal pain、vomiting、liver enzyme abnormalities、3casesrash、pleural effusion in1case with pulmonary atelectasis、joint pain1cases),after comprehensive treatment the clinical symptomsdisappeared。 The Extrapulmonary complication had statisticallysignificant（χ2=4.443，p<0.05）between experimental group and contrplgroup.The duration of hospitalization had difference between group andcontrpl group （χ2=7.305，p<0.05）。Conclusion: 1、During2011-2013in GuangZhou city MP infection in children wasabout54.4%.And we can obtained in GuangZhou city during2011-2013withoutthe occurrence of pneumonia mycoplasma infection outbreak。2、Rapid pneumonia mycoplasma culture positive rate:24.36%。how toimprove rapid MP culture positive rate need further studied。3、GuangZhou MP total drug resistance rate:64.76%。Roxithromycin was69.52%,Erythromycin was60.1%,azithromycin was26.67%,Sparfloxacin was0%.So children MP infection we suggest to select azithromycin.4、MP23S rRNA V mutations associated with MP drug resistance.2063and2064sites are most common。5、Azithromycin Sequential therapy is safe and effective without invivo induced resist strains,but it have connection between irregularapplication azithromycin and MP drug resistance,without regularmedication and drug resistance rate was positively correlated with theapplication times。6、MP not only infect respiratory tract,also can cause extrapulmonary complications through immune mechanism。The MP drug resistancestrains infection had such clinical characteristics：extrapulmonarycomplications more and serious。...