新生儿重症监护室细菌耐药的调查

Investigation of bacterial resistance in neonatal intensive care units

目的 了解新生儿重症监护室(NICU)内感染常见病原菌的菌种、构成比及耐药情况,以利临床合理选用抗生素。方法 2000年至2001年2年间对NICU中110名新生儿进行细菌学和细菌耐药检测,对不同标本群的阳性结果用x^2检验进行统计分析。结果 110名新生儿共接受了331次细菌学检查,阳性为121次,其中革兰阴性菌91株,革兰阳性菌30株,主要为鲍曼不动杆菌、铜绿假单胞菌、大肠埃希菌。阳性菌株中13株为产ESBLs阳性菌株,气道内组检出大肠埃希菌ESBLs阳性率高于非气道内组(x^2=3.9158,P<0.005)。革兰阳性菌耐药率最高的为红霉素(95.0％)和青霉素(92.6％),耐药率最低的为万古霉素(3.3％);革兰阴性菌耐药率最高的为氨苄西林(98.8％)、头孢呋新(98.2％)和氨苄西林/舒巴坦(90.0％),耐药率最低的为阿米卡星(6.1％)和亚胺培南(6.7％)。检出率最高的三种菌株对氨苄西林的耐药率最高,分别为鲍曼不动杆菌100％,铜绿假单胞菌96.0％,大肠埃希菌90.5％。结论 NICU中革兰阴性菌仍是导致感染的主要病原体,ESBLs阳性菌株的增加与临床上侵袭性医疗手段的运用增多相关。氨苄西林已经成为临床上耐药率最高的药种之一,革兰阳性菌对万古霉素、革兰阴性菌对阿米卡星和亚胺培南具有良好的敏感性。

Objective To explore the etiological bacterial and the drug resistant patterns in neonatal infections at the neonatal intensive care unit (NICU). Methods Bacterial cultures and their resistance surveillance were conducted in 110 newborns at the NICU of Xinhua Hospital during 2 years time from 2000 to 2001. The results were analyzed according to NCCLS (2000). The chi-square test was used to determine the difference of positive results in different groups. Results Three hundred and thirty-one cultures were performed from 110 infected newborns and specimens 121 were positive. The total positive rate was 36.6%. Among these 121 positive strains, 91 were gram-negative and 30 gram-positive. The main pathogens were Acinetobacter baumannii (25 strains) , Pseudomonas aerug-inosa (25 strains) ,and Escherichia coli (21 strains). Thirteen ESBLs positive strains were found in the 121 strains. The occurrence rate of ESBLs positive strains from Escherichia coli in the endotracheal group was higher than other groups with significant difference ( X =3. 9158, P < 0. 005). Resistance of Gram-positive strains to erythromycin (95.0% )was the highest, to penicillin was the higher(92. 6% ) , and to vancomycin (3. 3% ) was the lowest. The highest resistance of Gram-negative strains was to ampicillin (98.8% ) , to cefuroxime the next(98.2% ) and ampi-cillin/sulbactam the lowest(90.0% ). The gram-negative strains were lowly resistant to both amikacin (6. 1% ) and imipenem (6. 7% ). The three main isolates that have been cultured most frequently were;l. Acinetobacter baumannii highly resistant to ampicillin (100% ) , and to Ciprofloxacin (92.0% ) ; 2. Pseudomonas aeruginosa highly resistant to ampicillin (96.0% ) and cefazolin (96.0% ) ; 3. Escherichia coli highly resistant to ampicillin (90. 5% ) . Conclusion Gram-negative strains are the main pathogens causing infections in NICU. Adopting cultures from the endotrache is one of the most important procedures to reveal the pathogens in NICU. Invasive procedures are the main sources to cause ESBLs positive infection. Either gram-positive strains or gram-negative strains are highly resistant to ampicillin. Gram-positive strains are rarely resistant to vancomycin and gram-negative strains are still sensitive to arni-kacin and irnipenem.