Isolation and drug resistance analysis of 102 strains of Haemophilus from respiratory tract infection

Objective To investigate the isolation, identification and susceptibility of Haemophilus, and the produce rate of β-Lactamases. Methods Haemophilus isolated by a special Haemophilus culture medium(HAE) was identified by satellitism in sheep blood agar and Mueller-Hinton agar. The K B method was used to determine the susceptibility. Results One hundred and two strains of Haemophilus were isolated from 726 sputum or throat swab specimens and the rate was 14.0%. The prevalence of β-Lactamases in Haemophilus was 14.7%. The percentages of resistance of Haemophilus influenzae and Haemophilus parainfluenzae to ampicillin were 50.0% and 40.0%,trimethoprim sulfamethoxazole 79.0% and 82.5%, and ciprofloxacin 69.4% and 75.0% respectively,but the rate of susceptibility of Haemophilus to azithromycin, aztreonam, and the second and third generation cephalosporins was over 90%. Conclusion The rate of isolation of Haemophilus in the sputum swab was not obviously different form that in the throat swab. Haemophilus influenzae were the major form of respiratory tract infection. Azithromycin, aztreonam, and the second and third generation cephalosporins still have the excellent activity to the strains and can be used chiefly.