早产儿细菌感染病原菌分布及耐药性变迁

目的探讨新生儿重症监护病房（NICU）早产儿细菌感染的病原菌分布及耐药性变迁，为防治早产儿感染、指导临床用药、减少耐药性提供依据。方法对1997年10月至2007年10月收入我院NICU治疗的早产儿感染患儿血液、痰液、脐部等部位标本进行培养并做药敏试验。结果①733株细菌中革兰阴性杆菌占65．35％，以肺炎克雷伯氏菌、大肠埃希氏菌及铜绿假单胞菌为主；革兰阳性球菌占31．11％，以金黄色葡萄球菌、表皮葡萄球菌及其他凝固酶阴性葡萄球菌为主；②血培养中L型细菌的检出率为28．74％，葡萄球菌中耐甲氧西林葡萄球菌占23．68％，革兰阴性杆菌中产超广谱β-内酰胺酶（ESBLs）细菌占22．00％，产头孢菌素酶（AmpC）细菌占1．28％，产超超广谱β-内酰胺酶（SSBL）细菌占0．85％；③革兰阳性球菌对青霉素类、大环内酯类抗生素耐药率高达50％以上，且有升高趋势，对万古霉素及哌拉西林／他唑巴坦耐药率较低。革兰阴性杆菌对一代、三代头孢菌素类抗生素的耐药率高达50％以上，对四代头孢菌素类、碳青霉烯类及加酶抑制剂的β-内酰胺类抗生素耐药率较低。嗜麦芽窄食假单胞菌对亚胺培南-西司他汀（泰能）100％耐药，对头孢哌酮／舒巴坦、环丙沙星、哌拉西林／他唑巴坦的耐药率较低。结论①早产儿细菌感染病原菌以革兰阴性杆菌为主，且病原菌的耐药性有升高趋势；②要重视凝固酶阴性葡萄球菌、铜绿假单胞菌及嗜麦芽窄食假单胞菌等条件致病菌的感染，加强消毒隔离；③临床上要依据药敏试验结果合理选用抗生素，减少耐药菌株的产生。

The distribution of pathogens and variation of drug resistance in bacterial infection of preterm infants

Objective To investigate the distribution of pathogens and variation of drug resistance in preterm infants infected by bacterias, for the purpose of prevention of preterm infections and guidance of clinical medication. Methods Samples of blood,sputum and umbilical part et al,from the infected preterm infants admitted to our neonatal intensive care unit from October 1997 to October 2007 were cultured and susceptibility tested. Results （1）Of the total 733 isolated pathogenic strains, the isolates rate of Gram-negative bacillus was 65.35% ,and the main pathogens were Klebsiella pneumoniae, Escherichia coli and Pseudomonas aeruginosa. The isolates rate of Gram-positive coccus was 31. 11% , and the main pathogens were Staphylococcus aureus, Staphylococcus epidermidis,and other coagulase negative staphylococcus; （2）75 strains （28.74%）from blood cultures were L-type bacterias. 23.68% of the staphylococci were meticillin resistant. Among the Gram-negative bacillus, the detection rate of Entended spectrum beta-laetamase producing strains （ESBLs）, AmpC beta-laeta- mases, and super spectrum beta-lactamases（SSBL） , were 22.00% , 1.28 % and 0.85 % , respectively ; （3）The resistance rates of Gram-positive coccus to penicillins and macrolide antibiotics were higher than 50.00% , but were low to vancomycin and piperacillin/tazobactam. The resistance rates of Gram-negative bacillu to archicephem and tert-cephem antibiotic were higher than 50.00% , and were low to tetra-cephalosporins, carbopenems, β-lactam antibiotics plus enzyme inhibitor. The resistance rates of Stenotrophomonas maltophilia to imipenem were 100% ,but were low to cefoperazone/sulbactam, ciprofloxacin, piperacillin/tazobactam. Conclusion （1） The main pathogens of bacterial infection in preterm infants were Gram-negative bacillus, and the drug resistances of pathogens were increased during the last ten years ; （2）More attention should be paid to the opportunistic infection by coagulase negative staphylococcus, Pseudomonas aeruginos