RESUMEN

Objective To investigate the antibiotic resistance profile and ftsⅠ genotypes of Haemophilus influenzae isolates from respiratory tract in children.Methods A total of 141 consecutive nonduplicate clinical strains of H.influenzae were collected from January to March 2016.Antimicrobial susceptibility was determined using Kirby-Bauer method.Beta-lactamase production was detected by nitrocefin disk test.PCR technique was employed for ftsⅠ genotyping.Antimicrobial resistance was compared between differentfisⅠ genotypes.Results The prevalence of β-lactamases was 40.4％ (57/141) in H.influenzae isolates.More than half (53.2％,75/141) of the strains were resistant to ampicillin.Mutation offtsI gene was positive in 72.3％ (102/141) of the isolates.The dominant genotype of genomic beta-lactamase-negative ampicillin-resistant (gBLNAR) strains was type Ⅲ (72/102,70.6％).The gBLNAR strains showed higher resistance rate to ampicillin and cefuroxime than the genomic beta-lactamase-negative ampicillin susceptible (gBLNAS) strains (P＜0.05).Conclusions High prevalence offisⅠgene mutation is found in the strains ofH.influenzae isolated from respiratory tract in children.The dominant genotype of gBLNAR strains was type Ⅲ.Mutation offtsⅠ gene in H.influenzae is associated with higher resistance rate to ampicillin and cefuroxime.