血培养中病原菌的分布及耐药分析

目的：了解血培养中分离菌株的构成比及耐药情况。方法：标本经BacT／Alerti120血培养仪培养，分离所得菌株用法国梅里埃API系统进行鉴定和K—B法做药敏。结果：在2046份标本中，分离菌株279株，阳性率为13．63％。其中革兰阳性菌占85．66％，革兰阴性菌占14．33％，耐甲氧西林凝固酶阴性葡萄球菌（MRCNS）检出率非常高，达69．45％（116／167），远远高于MRSA的检出率15．62％（5／32）。药敏结果显示未发现耐万古霉素的阳性球菌。MRCNS中复方磺胺甲恶唑、青霉素、红霉素、环丙沙星、克林霉素，氯霉素、四环素的耐药率分别为100％，100％，100％，100％、66．7N、66．7％，33．3％；耐甲氧西林金黄色葡萄球菌（MRSA）中分别为100％，100％，80％，20％，40％，40％，60％。在粪肠球菌药敏中青霉素、氨苄西林始终保持较稳定的抗菌活性，耐药率均〈10％，对万古霉素最敏感。革兰阴性菌对第一、第二代头孢菌素耐药都在50％以上，对喹诺酮类如环丙沙星耐药高达60％，对碳青酶烯类最敏感。结论：及时掌握血培养中细菌分布与其对抗菌药物耐药现象和动态，对合理用药具有重要意义。

Distribution and resistance of pathogentic bacteria in blood culture

Objective To investigate the distribution and drug-resistance of the bacteria isolated from blood in our hospital during last two years.Methods Bacteria in blood was cultured with BacT/Alert 120,and identified with API identified tests(API Inc,France).Antibiotics sensitivity was examined with Kirby-Bauer(K-B) method.Results Two hundred and seventy-nine strains of bacteria were isolated from 2046 blood culture samples,Gram-negative bacteria strains(85.66%),gram-positive bacteria strains(14.33%).The positive rate of MRCNS was much higher than that of MRSA(69.45% vs 15.62%).No resistance to vancomycin was found in these strain.The drug-resistance of MRCNS to trimethoprim/sulfamethoxazole(100%),penicillin G(100%),erythromycin(100%),ciprofloxacin(100%),clindamycin(66.7%),chloramphenicol(66.7%),tetracycline(33.3%) were higher than that of MRSA to these drugs(100%,100%,80%,20%,40%,40% and 60% respectively).Resistance of enterococus faecalis to penicillin G,ampicillin was smaller than 10%.Gram negative bacteria was sensitive to carbopenems.Its resistance to first and second generation of cephlosporins was higher than 50%,and higher than 60% to quinolones resistance. Conclusion The distribution and their drug resistance characteristics of pathogenic bacteria in septicemia are important to the application of antibiotics.