Text Box: THE CHARACTERISTIC OF HAEMOPHILUS ISOLATES FROM PEDIATRIC INFECTION AND ANALYSES OF ANTIMICROBIAL RESISTANCE Guo Y-F, Zhang M-H and Zhen J-H Beijing Children's Hospital, China Objectives: To improve the culture methods for Haemophilus spp in routine detection and investigate the characteristics of Haemophilus. spp infection in the different parts of bodies of children, age, seasons and the conditions of antibiotic resistance. Methods: Totally 4924 clinical specimens were obtained in Beijing Children ‘s hospital.between 1999-2000. The chocolate media containing V factor, yeast extract and Vancomycin was appiled for cultuer. Bacitracin(300ug/disk) was used to inhibit other bacteria .K-B disk diffusion was employed for antibiotic susceptibility test and nitrocefin was used for β-lactamase detection. Results: 583 Haemophilus. spp strains were isolated. Among them, the rates of detection of specimens from throat, sputum, genital tract, urine, bronchial wash and pleural fluid were 30.2%, 8.7%, 15.4%, 0.4%, 1.9%, and 0.8%, respectively. The positive rates of detection of Haemophilus Para-influenzae (Hpi ) from bronchial wash , throat and sputum were higher than the that of Haemophilus influenzae (Hin). There was no apparent difference in gental tract. The positive rates of detection were increased with the age for the specimens of throat, sputum, bronchial wash.The antimicrobial resistance rate(I+R) to Ampicillin, Trimethoprin /sulfamethoxazole, Rifampin and Chloramphenic were 18%, 41%, 50%, and 13% for Hin isolates and 28%, 50%, 31% and 9.7% for Hpi isolates. The antimicrobal resistance rates of both Hin and Hpi to mipenam, cefaclor, cfuroxime, ceftriaxone, cefotaxime,ceftazidim, aztreonam, amoxicillin /cla,clarithromycin and ciprofloxacin were below 6.5%.75of 451(16.6%) isolates produced B-lactamase. Conclusions: The data indicated that the use of the bacitracin (300ug/disk) in the routine culture can improve the positive rate of detection. The low virulence conditional bacteria has become pathogenic bacteria, which can cause some serious infections in children,.so it's important to enhance the detection of Haemophilus. spp in other parts of bodies except expiratry tract..The pedeatricians should consern more about the antimicroal test and detection of β-lactamase to provide good treatment. 1876