Isolation identification and drug resistance analysis of Haemophilus in the elderly with respiratory tract infection

Objective To investigate the isolation,identification and susceptibility of Haemophilus,and the produce rate of β-lactamases in the elderly with respiratory tract infection.Methods Haemophilus isolated by a special haemophilus culture medium was identified by satellites in sheep blood agar and Mueller-Hinton agar.The positive results of both were confirmed by NHI card.The producing rate of β-lactamases was examined by cephalosporin 87/312.The agar diffusion method was used to determine the susceptibility.Results Of one hundred and nineteen strains of haemophilus isolated from 1 138 specimens,the detected rate accounting for 10.5%,there were 25 strains of haemophilus influenzae(21.0%) and 94 haemophilus parainfluenzae (79.0%).The haemophilus β-lactamases producing rate was 23.5%.The rate of drug resistance was higher to levofloxacin,ampicillin and bactrim,reaching 15.0% to 54.6% in haemophilus influenzae,and 19.2% to 56.5% in haemophilus parainfluenzae,but was lower to amoxicillin/clavulanic acid,aztreonam and the second and third generation cephalosporins,all below 10%.Conclusions The isolated haemophilus parainfluenzae are the major form of respiratory tract infection.The susceptibility of amoxicillin/clavulanic acid,aztreonam and the second and third generation cephalosporins is higher than that of the other and could be of choice.