某院流感嗜血杆菌耐药性及其对氨苄西林耐药机制

目的了解流感嗜血杆菌对常用抗菌药物的耐药性及其对氨苄西林的耐药机制。方法采用纸片扩散法和头孢硝噻吩纸片法,对2012年1月1日—12月31日某院住院及门诊患者送检标本分离的流感嗜血杆菌耐药性和β-内酰胺酶进行检测,聚合酶链反应(PCR)法对耐氨苄西林菌株进行TEM型和ROB型β-内酰胺酶基因扩增。结果 100例流感嗜血杆菌感染患者,年龄段分布主要为1~10岁,占61.00%。流感嗜血杆菌对氨苄西林耐药率为35.00%(35株),对复方磺胺甲口恶唑耐药率高,达64.65%;对左氧氟沙星和阿奇霉素敏感率最高,分别为97.96%、96.84%,对环丙沙星、头孢噻肟、氯霉素、头孢呋辛和氨苄西林/舒巴坦敏感率均较高,依次为96.91%、92.78%、85.71%、77.89%和74.75%。100株流感嗜血杆菌中,21株β-内酰胺酶阳性,且均为氨苄西林耐药株。对35株耐氨苄西林菌株进行TEM和ROB基因检测,结果 22株TEM型阳性,未检出ROB阳性株。结论流感嗜血杆菌对复方磺胺甲口恶唑敏感率低,对其他常用抗菌药物敏感率高;流感嗜血杆菌对氨苄西林的主要耐药机制为产TEM型β-内酰胺酶。

Antimicrobial resistance and ampicillin resistance mechanism of Haemophilus influenzae from a hospital

ObjectiveTo study the resistance to commonly used antimicrobial agents and ampicillin resistance mechanism of Haemophilus influenzae (H. influenzae). MethodsAntimicrobial resistance and β lactamase of H. influenzae isolated from inpatients and outpatients in a hospital from January 1 to December 31, 2012 were detected by Bauer Kirby disc diffusion method and nitrocefin based test, TEM and ROB β lactamase genes were amplified by polymerase chain reaction (PCR). ResultsOf 100 patients infected with H. influenzae, 61.00% were aged 1-10 years. The resistance rate to ampicillin was 35.00%(n=35)，resistance to sulphamethoxazole/trimethoprim was up to 64.65%；susceptibility rate to levofloxacin, azithromycin, ciprofloxacin, cefotaxime, chloramphenicol, cefuroxime, ampicillin / sulbactam   was 97.96%, 96.84%,96.91%, 92.78%,85.71%,77.89% and 74.75% respectively. Of 100 H.influenzae isolates, 21 were  β lactamase positive strains, and all were resistant to ampicillin. 35 ampicillin resistant strains were performed TEM and ROB genes detection, of which 22 were TEM positive, ROB positive strain was not found. ConclusionH.influenzae is sensitive to most antimicrobial agents except sulphamethoxazole/trimethoprim. Producing of TEM β lactamase is the major mechanism of ampcillin resistance in H.influenzae.