Abstract: Objective  The distribution of pathogenic bacteria and characteristics of drug resistance changes of bronchoalveolar lavage in hospitalized  children with pneumonia in Suzhou  2013 to 2018 were retrospectively analyzed,  to provide a basis for the rational use of antimicrobial agents to effectively control related infections. Methods  For the children with pneumonia who were hospitalized from January 2013 to December 2018,  bronchoalveolar lavage(BALF) was extracted to detect the pathogen for the need of diagnosis and treatment.Results  A  total of 3 242 BALF samples were collected,  from which 418 samples of pathogens were isolated.The positive rate of pathogen isolation was 12.89%. The main strains were Streptococcus pneumoniae and Haemophilus influenzae,  with the detection rates of  38.28%  and  21.05%,  respectively. Streptococcus pneumoniae was significantly resistant to erythromycin,  compound neostigmine,  clindamycin and tetracycline,  and the drug resistance rate was not significantly changed (P>0.05). Haemophilus influenzae was highly sensitive to ceftriaxone,  metopenan and ceftapexin,  and the drug resistance rate to ampicillin increased yearly (P<0.05).The positive rate of βlactamase was also significantly increased (P<0.05).Conclusion  BALF etiological test can be used to detect children with pneumonia at a young agebecause of the refractory pneumonia with treatment difficulties and no clear etiological data.The distribution and drug resistance rate of  BALF pathogenin Soochow have their own characteristics,  so drug resistance monitoring and analysis should be strengthened. The clinical rational drug use should be duided according to the characteristics of the drug use in children.

Key words: pneumonia, , bacterial, bronchoalveolar lavage fluid, children