Analysis of serotype distribution and antibiotic resistance of Haemophilus influenzae in hospitalized children / 中华实用儿科临床杂志

ABSTRACT

Objective:To explore the serotype, antibiotic resistance and β-lactamase gene of Haemophilus influenzae strains isolated from hospitalized children, thus providing reference for clinical diagnosis and treatment. Methods:A total of 148 Haemophilus influenzae strains collected from January 2016 to December 2018 in hospitalized children of Children′s Hospital, Capital Institute of Pediatrics were retrospectively analyzed.The serotype and genotype of Haemophilus influenzae strains were examined by slide agglutination test and PCR, respectively.The sensitivity of isolates to Ampicillin and other antimicrobials was detected by the E-test and disk diffusion methods.The β-lactamase phenotype was tested by nitrocefin disk method.The carrying of β-lactamase gene TEM-1 and ROB-1 were detected by PCR.The drug resistance rate was compared by χ2 test. Results:All the 148 strains were nontypeable Haemophilus influenzae (NTHi), and capsular gene was not amplified.The rate of resistance to Ampicillin, Ampicillin/Sulbactam, Cefuroxime, and Azithromycin were 68.9%(102/148 strains), 40.5%(60/148 strains), 53.4%(79/148 strains) and 56.1%(83/148 strains), respectively.The Haemophilus influenzae isolates showed the highest resistance rate to Trimethoprim-sulfamethoxazole, which was up to 91.9%(136/148 strains). The sensitive rate of isolates to Ceftriaxone, Meropenem and Levofloxacin were all 100.0%(148/148 strains). The prevalence of β-lactamase was 64.8%(96/148 strains) in Haemophilus influenzae and the genotype was TEM-1.The drug resistance rates of β-lactamase positive strains to Ampicillin, Ampicillin/Sulbactam and Azithromycin were significantly higher than those of other strains( χ2=123.222, 27.973, 70.273, all P<0.01). Conclusions:The most prevalent serotype of Haemophilus influenzae is NTHi in children. Haemophilus influenzae carried TEM-1 gene had a high positive rate of β-lactamase production, which was the main mechanism of drug resistance to Ampicillin.Ceftriaxone and Meropenem were the most active agents against Haemophilus influenzae.