流感嗜血杆菌下呼吸道感染的实验和临床研究

Laboratory and clinical investigation on lower respiratory tract infection by Haemophilus influenzae

目的探讨提高流感嗜血杆菌（Ｈｉ）分离率的方法，调查Ｈｉ下呼吸道感染的临床特点及对抗生素的敏感性。方法比较改良哥伦比亚巧克力琼脂（ＩＣＣＡ）与血琼脂加金黄色葡萄球菌划线（ＢＡＳＳ）对Ｈｉ的分离率；以ＫｒｉｂｒｙＢａｕｅｒ（ＫＢ）法测定Ｈｉ对２０种抗生素的敏感性，以肉汤微量稀释法测定１２种抗生素对Ｈｉ的最小抑菌浓度（ＭＩＣ）；分析９２例Ｈｉ下呼吸道感染的临床特点。结果ＩＣＣＡ的分离率为２０％，与ＢＡＳＳ法（１３％）比较，差异有显著性（Ｐ＜０．０１）；第三代头孢菌素和喹诺酮类抗生素抗菌活性高，氨苄西林的耐药率为２１％，而第一代头孢菌素耐药率达４５％～４９％；９２例下呼吸道感染患者中６７例（７３％）临床上以支气管肺炎为主要表现。结论ＩＣＣＡ可提高Ｈｉ的分离率；Ｈｉ下呼吸道感染临床表现无特异性，但对Ｈｉ耐药有增加趋势。

Objective To improve the positive rate of Hi isolation and to study the epidemiology, antibiotic sensitivity and clinical characteristics of the lower respiratory tract infection by Hi. Methods Modified Columbia chocolate agar(ICCA) was compared with blood agar staphy stick (BASS) for the primary isolation of Hi from sputa. The sensitivities of 20 antibiotics to Hi were determined in vitro by KB method and MICs of 12 antibiotics were determined by broth microdilution method. The clinical characteristics of 92 cases with lower respiratory tract infection by Hi were analyzed. Results The isolation rate of Hi by ICCA was 20%,which was higher than 13% of BASS( P <0.01). The third generation cephalosporins and the quinolones were most active against Hi. The resistant rate against Hi of ampicillin was 21%, however, that of the third generation cephalosporins was 45%～49%. 67(73%) of 92 cases were bronchopneumonia. Conclusions The isolation rate of Hi could be improved by ICCA. The clinical characteristic of lower respiratory tract infection by Hi was not specific. There has been a steady increase of antibiotic resistance during these years.