浙江省儿童医院1991～2000年儿童败血症病原菌变迁及耐药分析

目的：探讨浙江省部分地区近10年小儿败血症病原菌的变迁及近年常见致病菌的耐药性。方法：对1991－2000年浙江省儿童医院住院患儿送检的血标本,分别采用肉汤（1991－1996年）及VITAL AER全自动血培养仪（1997－2000年）进行培养,采用API系统及VITEK全自动微生物鉴定仪进行菌株鉴定及药敏试验,按美国NCCLS标准判断结果。结果：革兰阳性菌检出构成比明显高于革兰阴性菌,凝固酶阴性葡萄球菌（CNS）10年间逐年增加,到2000年检出构成比达69．0％,金黄色葡萄球菌及大肠埃希菌逐年下降,分别从1991年35．4％、18．2％下降到2000年5．3％、1．5％。葡萄球菌对青霉素的耐药率达90％以上,对红霉素的耐药率70％以上;耐苯唑西林CNS达60．2％,明显高于金黄色葡萄球菌10．3％;未发现耐方古霉素的葡萄球菌和肠球菌。大肠埃希菌、假单胞菌及其他肠杆菌对亚胺培南／西司他丁均敏感,而对氨苄西林、第1代头孢菌素的耐药率多在50％以上。结论：（1）儿科败血症病原以革兰阳性菌占优势,葡萄球菌居首位,新生儿和婴儿以CNS为主,学龄儿童以金黄色葡萄球菌为主;（2）革兰阴性菌中,新生儿和婴儿以大肠埃希菌为主,学龄儿童以沙门菌为主;（3）儿科检出菌存在严重耐药问题,及时监测病原菌变化及耐药趋势以指导临床用药至关重要。

Changes of pathogenic bacteria in pediatric patients of septicemia and drug resistance there of in Zhejiang Children's Hospital 1991 approximately 2000

OBJECTIVE: To investigate the changes of pathogenic bacteria detected from the blood culture of pediatric patients with septicemia in the past 10 years, and to observe the drug resistance thereof in the past two years. METHODS: The blood samples of 4 425 pediatric patients aged 0 approximately 14 with the diagnosis of septicemia 1991 approximately 2000 in Zhejiang Children's Hospital were cultured in broth (1991 approximately 1996) or VITA AER blood culture apparatus (1997 approximately 2000). Analytic Product Inc. (API ) system and KB paper strip method and VITEK automicroscan were used to identify the species and conduct drug resistance test. The results were interpreted according to the guideline of National Committee for Clinical Laboratory Standards. RESULTS: In the past 10 years, Gram-positive bacteria remained the more frequent pathogens than Gram-negative bacteria in pediatric patients with septicemia. The proportion of coagulase-negative staphylococcus (CNS) had been increasing and reached 69% in 2000. The proportions of Staphylococcus aureus and Escherichia coli decreased from 35.4% and 18.2% in 1991 to 5.3% and 1.5% in 2000. In the past two years, the drug resistance rate of staphylococci against penicillin and erythromycin were more than 90% and 70% respectively. The oxacillin resistance rate of CNS was 60.3%, significantly higher than that of Staphylococcus aureus (10.3%). No strain of Staphylococcus and Enterococcus resistant to vancomycin was found.Escherichia coli and Psudomonas aeruginosa and other species of Enterobacteriae were sensitive to imipenem/cilastin sodium, whereas the resistance rate of them to ampicillin and first generation cephalosporins was more than 50%. CONCLUSION: (1) Gram-positive bacteria are the predominant pathogens of pediatric patients with septicemia, with the species of Staphylococcus ranking first among which CNS is the main pathogen for infants and Staphylococcus aureus is the main pathogen for school children. (2) Escherichia coli is the most frequently found pathogenic Gram-negative bacterium in infants with septicemia whereas Salmonella in school children. (3) Drug resistance of isolated pathogenic bacteria in department of pediatrics is a serious problem. Monitoring the change of pathogen and the trends of antimicrobial resistance is very important in guiding therapy.