Detection And Clinical Analysis Of Common Pathogen-resistant Genes In Children With Lobar Pneumonia

Objective : To understand the detection of bronchoalveolar lavage fluid(BALF)in children with mycoplasmal pneumonia(MP)and streptococcus pneumoniae(SP),and test related resistance genes.Regional clinical characteristics of children.Methods:A total of 69 BALF children with lobar pneumonia were collected,and the fluorescent and real-time quantitative polymerase chain reaction(FQ-PCR)were used to detect MP and SP nucleic acids in the above specimens.For MP-positive children,complete the detection of 23 SrRNA V region mutation sites(A2063G,A2064 G,A2063C,and A2063T).Those who test positive are included in the mutation group,and those who test negative are included in the non-mutation group.Detection of drug resistance genes(ermB,mefA,and mefE)related to macrolide antibiotics(MALs),and amplification and sequencing of the penicillin-binding proteins PBP1 A,PBP2B,and PBP2 X.The test results were divided into drug-resistant gene negative groups and drug-resistant genes Positive group,compare clinical data of children in each group.Results:1)In 69 cases of BALF in children with lobar pneumonia,54 were positive for the pathogen,and the positive rate was 78.26%.Among them,48 cases were MP positive(69.57%),14 cases were SP positive(20.29%),and 8 cases were MP combined with SP infection(11.60%);2)A total of 37(77.1%)site mutations were detected in 48 children with MP-infective lobar pneumonia.The mutation rates were: A2063 G,A2064G,A2063 C,A2063T.Multiple mutation sites can exist in the same child at the same time.A total of 6 cases(12.5%)of 4 mutation sites occurred simultaneously.A2063 G,A2063C,and A2064 G combined in 10 cases(20.8%),A2063 G combined with A2064 G positive in 6 cases(12.5 %),A2063 G combined with A2063 T positive 6 cases(12.5%),A2063 G combined with A2063 C positive 6 cases(12.5%);3)In 14 children with SP infection,the positive rates of ermB and mefA were 64.3% and 14%,respectively,and 2 cases(14.3%)occurred simultaneously,and no mefE gene was detected;4)PBPs gene mutations were found in 7 children with SP infection,including 3 cases of PBP1 A and PBP2 X mutations,3 cases of PBP2 B and PBP2 X mutations,1 case of PBP1 A and PBP2 B mutations,and PBP2 X mutations were the most common(85.7%).In this region,THr371 Ser and THr371 Ala were substituted for amino acids in PBP1A;THr451Ser,THr451 Ala and Ala624 Glu were substituted for amino acids in PBP2B;THr371Arg and Met400 Arg were substituted for amino acids in PBP2X;5)Compared with the MP non-mutated group,the serum levels of CRP,PCT and LDH were higher in children with the mutation group,and the proportion of patients with extrapulmonary complications increased.The duration of fever,length of hospital stay,days of MALs application and fever reduction were extended,and methylprednisolone was applied The proportion of IVIG increased significantly,and the above differences were statistically significant(P <0.05).Conclusion1)In children with MP infectious lobar pneumonia in this region,macrolide antibiotics,especially erythromycin resistance mutations,have a high rate of resistance,and mycoplasma infected with the same child has multiple resistance mutation sites;2)SP-infective lobar pneumonia,the positive rate for macrolide antibiotic resistance genes is also high,PBPs mutations were detected in 7 children with SP infection in this area,4 of them had high levels of Amide antibiotic resistance,3 patients with low level resistance;3)Children with lobar pneumonia with significantly elevated serum CRP,PCT,and LDH levels,many extrapulmonary comorbidities,average fever,and long hospital stay should consider MP resistance.