摘要
目的 测定 2 6株临床分离院内感染嗜麦芽寡养单胞菌对常用抗菌药物的耐药性 ,探索产 β-内酰胺酶菌株对亚胺培南的耐药机制。方法 采用琼脂二倍稀释法测定 19种抗菌药物对 2 6株临床分离的院内感染嗜麦芽寡养单胞菌的体外抗菌活性 ,并比较产酶株与非产酶株对抗菌药物的敏感性 ;测定产酶株所产 β-内酰胺酶对亚胺培南的稳定性和丝氨酸 β-内酰胺酶、金属 β-内酰胺酶抑制剂的抑酶保护效应。结果 新型氟喹诺酮类药物司帕沙星、左氧氟沙星、加替沙星和多西环素对 2 6株嗜麦芽寡养单胞菌有较强抗菌活性 ,抑菌率分别为 96 .2 %、96 .2 %、92 .3%、84 .6 % ,SMZ/ TMP和替卡西林 /克拉维酸抑菌率分别为 6 5 .4 %和 5 0 % ,亚胺培南、头孢他啶、头孢哌酮和氨曲南的敏感性较差 ,耐药率在 80 %以上 ;产酶株与非产酶株药敏结果比较 ,产酶株对含酶抑制剂β-内酰胺类抗生素的敏感性较非产酶株高 ,而对其它抗菌药物的敏感性变化不大。酶稳定性试验显示 ,有 4株产酶菌产碳青霉烯水解酶 ,酶抑制试验表明 ,克拉维酸对这 4株菌所产酶无抑酶保护效应 ,而金属β-内酰胺酶抑制剂 EDTA对 4株菌所产酶有抑制作用 ,且酶活性能被 Zn Cl2 复活。结论 新型氟喹诺酮类药物对嗜麦芽寡养单胞菌院内感染株有较强的抗菌活性 ;
Objective To investigate the resistant rates of S.maltophiliaisolated from nosocomial infections against 19 antimicrobial agents, and the resistant mechianism of imipenem was assayed by the stability of imipenem to β-lactamases. Methods Standard agar dilution method of NCCLS was performed on 26 strains isolated from nosocomial infections against 19 antimicrobial agents and spectrophotomertrical method was used to study the stability of imipenem to β-lactamases and β-lactamase inhibitors (clavulanate) and EDTA. Results Levofloxacin, sparfloxacin, gatifloxacin and doxycycline showed the highest antibacterial activity against S.maltophilia, their sensitive rates were 96.2%, 96.2%, 92.3% and 84.6%, respectively. SMZ/TMP and ticarcillin/clavulanic acid had a slightly lower sensitive rates, which were 65.4% and 50%, respectively. 26 strains showed the highest resistance to imipenem, ceftazidime, cefoperazone and aztreonam, the drug-resistant rates were over 80%. Compared with non β-lactamase producing strains, the β-lactamase producing strains showed the higher susceptibity to antibiotics with β-lactamase inhibitors. Test of the stability of imipenem to β-lactamases indicated that 4 of 26 strains produced carbapenem-hydrolyzing enzymes. Their hydrolytic activity was inhibited by EDTA, but not by β-lactamase inhibitors clavulanate, and they were partially reversible by the addition of zinc cation. Conclusions The newer fluoroquinolones has the highest antibacterial activity against S.maltophilia. Carbapenem-hydrolyzing enzymes produced by 4 strains are probably metallo β-lactamases.
出处
《中国抗生素杂志》
CAS
CSCD
北大核心
2003年第8期477-481,共5页
Chinese Journal of Antibiotics
基金
汕头大学研究与发展基金赞助 (项目编号 :L0 0 0 1 0 )
