血培养病原菌菌群分布及耐药分析

Analysis of the distribution and drug resistance of pathogenic bacteria in blood cultures

目的了解南华大学附属第一医院1997年1月～2004年6月年血培养病原菌菌群分布及近2年常见致病菌的耐药情况.方法4686份血标本经BACTEC 9050全自动血培养仪培养检测,分离出的致病菌用Sceptor半自动微生物鉴定系统进行鉴定及药敏试验.结果共分离出799株病原菌,血培养阳性率17.1%,检出病原菌分布于20个属,47个种.革兰阳性菌构成比明显高于革兰阴性菌,最常见的血培养菌属是葡萄球菌,占61.7%,其次是沙门菌、肠球菌、链球菌、埃希菌、假单胞菌及不动杆菌.各主要致病革兰阳性菌对万古霉素、呋喃妥因敏感,对环丙沙星较敏感,各主要致病革兰阴性菌对亚胺培南、头孢吡肟及阿米卡星敏感或较敏感.葡萄球菌的耐药情况严重,对青霉索耐药率高达90%以上,凝固酶阴性葡萄球菌(CNS)对多种抗生素耐药情况较金葡菌更严重.肠球菌对多数常用抗生素耐药,对红霉素耐药率高达85.9%.链球菌对青霉素和氨苄西林明显耐药.大肠埃希菌对亚胺培南、头孢替坦、阿米卡星敏感,对头孢吡肟、替卡西林/克拉维酸、阿莫西林/克拉维酸较敏感,对其他多种抗生素耐药.假单胞菌对亚胺培南、环丙沙星、阿米卡星及头孢他啶较敏感,对其他多种抗生素均耐药.不动杆菌对亚胺培南、环丙沙星、头孢吡肟、头孢噻肟、磺胺甲噁唑/甲氧苄啶及头孢他啶较敏感,对其他多种抗生素均耐药.沙门菌则对多种抗生素敏感.结论血培养病原菌以条件致病菌为主.检出菌中除沙门菌外,均存在严重耐药问题,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.

Objective To investigate the distribution of pathogenic bacteria in the blood culture collected from January 1997 to June 2004, and observe the drug resistance of common pathogenic bacteria during the last two years in the First Affiliated Hospital of Nanhua University. Methods 4,686 blood samples were (cultured) and detected by the BACTEC 9050, and the Sceptor half-automicroscan system was used to identify the pathogenic bacteria and conduct drug resistance test. Results Totally 799 strains of pathogenic bacteria were isolated. The positive rate was 17.1%. Pathogenic bacteria were distributed in 20 genera and 47 species. Gram-positive bacteria remained the more frequent pathogens than Gram-negative bacteria. The most common organism causing bloodstream infections was Staphylococcus (61.7% of the isolates). Salmonella Enterococcus, Streptococcus, Escherichia, Pseudomonas and Acinetobacter were next in order among the isolates. The dominant Gram-positive pathogenic bacteria were sensitive to vancomycin, nitrofurantoin and ciprofloxacin, and the dominant Gram-negative pathogenic bacteria were sensitive to imipenem, cefepime and amikacin. Staphylococcus was resistant against various antibiotics obviously and the resistance rate of Staphylococcus to penicillin was above 90%. The resistance rate of coagulase negative Staphylococcus (CNS) was higher than that of Staphylococcus aureus. Enterococcus was resistant against most antibiotics,and the resistance rate of Enterococcus to erythromycin was 85.9%. Streptococcus was resistant against penicillin and ampicillin. Escherichia coli was sensitive to imipenem, cefotetan, amikacin and was comparatively sensitive to cefepime, ticarcillin/clavulanate and amoxicillin/clavulanate, and resistant against various other antibiotics. Pseudomonas was comparatively sensitive to imipenem, ciprofloxacin, amikacin and ceftazidime, and resistant against various other antibiotics. Acinetobacter was comparatively sensitive to imipenem, ciprofloxacin, cefepime, cefotaxime, SMZ/TMP and ceftazidime, and resistant against various other antibiotics. Salmonella was sensitive to various antibiotics. (Conclusions) The most pathogenic bacteria isolated from blood specimens were opportunistic pathogens. (Except) Salmonella, drug resistance of isolated pathogenic bacteria is a serious problem. Monitoring the change of pathogen and the trends of antimicrobial resistance are very important in guiding the clinical administration of drugs.