Study on drug resistance of Mycoplasma pneumoniae and mutation of drug resistance gene locus in 23S rRNA
Objective To explore the drug resistance of Mycoplasma pneumoniae(MP)and the mutation of drug resistance gene locus in 23S rRNA in children with Mycoplasma pneumoniae pneumonia(MPP),so as to provide a basis for clinical treatment.Methods The clinical data of children with MPP admitted to our hospital from January 2022 to December 2023 were compared and analyzed.The mutation of drug resistance gene locus in 23S rRNA was detected by PCR technology.Combined with the results of drug sensitivity test,the correlation between drug resistance and gene mutation was discussed.Results A total of 78 MP strains were isolated from 78 children.These strains had a drug resistance rate of more than 50％to acetylspiramycin,erythromycin,clarithromycin and roxithromycin,with the drug resistance rates being 75.64％,73.08％,51.28％and 76.92％respectively.In contrast,the drug resistance rates to levofloxacin,ciprofloxacin and moxifloxacin were lower than 10％,which were 3.85％,3.85％and 1.28％respectively.Sequencing analysis of 78 MP strains showed that the mutation rate of drug resistance gene locus in 23S rRNA was 76.92％(60/78).Among them,47 strains had mutations at the A2063G locus(78.33％,47/60),9 strains had mutations at the A2064G locus(15％,9/60),and 4 strains had mutations at the A2063C locus(6.67％,4/60).Among the 47 MP strains with mutation at the A2063G locus,they were completely resistant to roxithromycin and acetylspiramycin.The drug resistance rates to erythromycin,clarithromycin,azithromycin,josamycin,levofloxacin,ciprofloxacin and moxifloxacin were 95.74％,63.83％,44.68％,17.02％,6.38％,6.38％and 2.13％respectively.Among the 9 MP strains with mutation at the A2064G locus,they were completely resistant to roxithromycin.The drug resistance rates to acetylspiramycin,erythromycin,clarithromycin,azithromycin and josamycin were 88.89％,88.89％,77.78％,33.33％and 22.22％respectively.They did not show drug resistance to levofloxacin,ciprofloxacin and moxifloxacin.Among the 4 MP strains with mutation at the A2063C locus,they were completely resistant to roxithromycin,acetylspiramycin and erythromycin.The drug resistance rate to clarithromycin was 75％,and the drug resistance rates to azithromycin and josamycin were 25％.They did not show drug resistance to levofloxacin,ciprofloxacin and moxifloxacin.There was no statistically significant difference in the drug resistance rates of MP strains with different mutation loci to commonly used antibacterial drugs(P＞0.05).In the group of patients with gene mutation,the incidences of cough,fever,shortness of breath,chills,weakened breath sounds,extrapulmonary infection and severe pneumonia were 100％,88.33％,66.67％,31.67％,71.67％,40％and 63.33％respectively.While in the group without gene mutation,the incidences of these symptoms were 94.44％,77.78％,44.44％,22.22％,27.78％,5.56％and 33.33％respectively.There was no statistically significant difference in cough,fever,shortness of breath and chills between the two groups(P＜0.05),but there was statistically significant difference in weakened breath sounds,extrapulmonary infection and severe pneumonia(P＞0.05).In the gene mutation group,14 cases had mixed infections,with an infection rate of 23.34％.Among them,4 cases had bacterial co-infections,including 2 cases of Pseudomonas aeruginosa,1 case of Klebsiella pneumoniae,and 1 case of Acinetobacter baumannii.10 cases had viral co-infections,including 5 cases of adenovirus,4 cases of influenza virus,and 1 case of respiratory syncytial virus.In the group without gene mutation,6 cases had mixed infections,with an infection rate of 33.34％.Among them,3 cases had bacterial co-infections,including 1 case of P.aeruginosa,1 case of K.pneumoniae,and 1 case of Streptococcus pneumoniae.Three cases had viral co-infections,including 2 cases of adenovirus and 1 case of respiratory syncytial virus.There was no statistically significant difference in the mixed infection rate between the two groups.Conclusion It was found that the drug resistance rate of MP strains in our hospital to macrolide antibiotics was relatively high,while the drug resistance rate to fluoroquinolone antibiotics was relatively low.The mutation of drug resistance gene locus in 23S rRNA was closely related to the drug resistance of MP strains.Among them,the mutation at the A2063G locus was significantly related to the high drug resistance rate.
Mycoplasma pneumoniaedrug resistance23S rRNAmutation of drug resistance gene locus
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