Distribution and antibiotic resistance profile of 350 strains of Haemophilus influenzae isolated from children / 中国感染与化疗杂志

ABSTRACT

Objective To analyze the distribution and antibiotic resistance profile of Haemophilus influenzae strains isolated from children for better antibiotic use.Methods The clinical and laboratory data concerning 350 strains ofH.influenzae were collected and analyzed retrospectively from 2014 to 2015 in our hospital,including pathogen source,production of beta lactamases and antimicrobial susceptibility.Antimicrobial susceptibility testing was carried out by using disk diffusion method.The results were interpreted according to the breakpoints of the Clinical and Laboratory Standards Association (CLSI) in 2014,and analyzed using WHONET 5.6 software.Results H.influenzae infection was more common in infants and young children.The prevalence of beta lactamase was 53.1％ in H.influenzae isolates.The H.influenzae isolates showed the highest resistance rate to trimethoprimsulfamethoxazole (76.9％),but relatively high susceptible rate to ciprofloxacin (99.1％),ceftizoxime (98.9％),chloramphenicol (95.4％),tetracycline (88.3％),amoxicillin-clavulanic acid (87.7％),cefuroxime (74.9％),azithromycin (65.4％),cefaclor (56.6％) and ampicillin (46.0％).All these H.influenzae strains were susceptible to ceftriaxone and meropenem.Conclusions Beta-lactamases are highly prevalent in the H.influenzae strains isolated from children,which is the main mechanism underlying ampicillin resistance in H.influenzae.Ampicillin is therefore not appropriate for first-line treatment ofH.influenzae infections.The H.influenzae strains are highly resistant to trimethoprim-sulfamethoxazole.In addition to beta-lactams,ciprofloxacin is the most active agent against H.influenzae strains,followed by chloramphenicol.