产β-内酰胺酶鲍曼不动杆菌的耐药性分析

Antibiotic Resistance of Acinetobacter Baumanii Producing beta-Lactamases

目的:分析产生β-内酰胺酶的鲍曼不动杆菌对14种抗菌药物的耐药性。方法:双纸片协同试验和标准纸片扩散法确证试验检测超广谱β-内酰胺酶(ESBLs),改良三维试验检测AmpC酶。琼脂纸片扩散法检测其对14种抗菌药物的敏感性。结果:89株鲍曼不动杆菌中,ESBLs检出率,双纸片协同试验为10.1%、纸片扩散法确证试验为11.2%,两法符合率为90.2%;改良三维试验检测AmpC酶,阳性率为84.3%,其中有5株细菌产生ESBLs和AmpC两种酶。产酶株对β-内酰胺类药物高度耐药,耐药率在60%～100%,对庆大霉素、阿米卡星、环丙沙星、复方新诺明、氯霉素等多重耐药,耐药率达70%～83.3%,对亚胺培南的耐药率在10%～25%。结论:鲍曼不动杆菌对β-内酰胺类药物耐药机制主要是产AmpC酶,产ESBLs较少;同时产ESBLs及AmpC酶菌株对临床常用抗菌药物呈现出多重耐药,耐药性严重,仅对碳青霉烯类的亚胺培南耐药率较低。

Objective To analyze the antibiotic resistance of Acinetobacter baumanii proucing beta-lactamases. Methods Double disk synergy test and standard disk diffusion susceptibility test were used to examine extended-spectrum beta-lactamases （ESBLs）. Modified three-dimensional test was used to examine AmpC β-lactamases. The antibiotic resistance of Acinetobacter baumanii to 14 antibacterial agents was detected by Kirby -Bauer method. Results In 89 strains isolated from clinical specimens, double disk synergy test showed that the rate of strains producing ESBLs was 10.1% , standard disk diffusion susceptibility test showed the rate was 11.2% ,the coincidence rate of the two methods was 90.2 %. Modified three- dimensional test showed that the rate of strains proudcing AmpC enzymes was 84.3%. There were 5 strains producing both ESBLs and AmpC enzymes. Those strains were highly resistant to β-lactamase antibiotics, while the resistance rates were 600 - 100%. The resistance rates against gentamicin, amikacin, ciprofloxacin, snlfanilamides and chloramphenicol were also very high（70% - 83.3% ）. The resistance rate to imipenem was only 10% - 25%. Conclusions Proudcing AmpC enzyme is the main mechanism of resistance to β-lactamase antibiotics in acinetobacter baumanii. The resistance of ESBLs and AmpC producing strains is serious, and multi-drug resistances are common. Imipenem is the most effective antibiotic to Acinetobacter baumanii.