摘要目的 晚发型败血症是新生儿期常见的感染性疾病,也是新生儿死亡的常见原因之一.新生儿一旦感染,病情可以迅速恶化,故早期有效的抗菌素治疗至关重要.该研究的目的 就是通过回顾性地分析晚发型新生儿败血症(LONS)的病原菌及其药敏,以指导临床早期对可疑LONS患儿合理用药.方法 对2002年1月1日至2005年12月31日温州医学院附属育英儿童医院NICU收住的具有临床表现以及至少一次血培养阳性的LONS临床特点、药敏进行回顾性分析.结果 102例LONS多通过皮肤、消化道、呼吸道等途径感染,临床表现无特异性.其中院内感染22例,社区感染80例,院内感染组与社区感染组比较,患儿胎龄小,体重轻,发病早(t=2.255、P＜0.01,t=8.818、P＜0.01,t=7.581、P＜0.05),差异有统计学意义.两组患儿血培养共检出110株病原菌,以凝固酶阴性葡萄球菌(CNS)居首(50/103,48.5%),其次为肺炎克雷伯杆菌(16/103,15.5%)、金黄色葡萄球菌(9/103,8.7%).社区感染主要病原菌为葡萄球菌属和大肠埃希菌,院内感染则为肺炎克雷伯菌.大部分(＞80%)的葡萄球菌尤其是CNS对青霉素类、红霉素及头孢唑啉耐药,MRSA达66.7%(6/9),但对万古霉素未发现耐药,大部分对利福平亦敏感.几乎所有(15/16)的ESBLS肺炎克雷伯菌具多重耐药性,仅对碳青霉烯类、氨基糖苷类以及喹诺酮类等少数抗菌药物敏感.发现1例对万古霉素耐药的粪肠球菌,然而,未发现B组链球菌感染的病例.结论 LONS临床表现非特异性,B组链球菌不是温州地区社区感染LONS的主要致病菌.由于医院和社区抗菌素的滥用,出现越来越多的多重耐药菌.对于可疑败血症患者应常规进行血培养以确定病原菌,并根据最可能的病原菌选用相关抗生素.为减少多重耐药菌感染的发生,应尽量减少第三代头孢菌素的使用.

abstractsObjective Late onset neonatal septicemia(systemic infection after 72 hours of life)remains a major cause of neonatal morbidity and mortality.Early treatment with appropriate antibiotics is critical since infected infants Call deteriorate rapidly.The aim of this study was to review the pathogens responsible for late onset neonatal septicemia(LONS)and their antimicrobial susceptibilities in order to guide the initial selection of appropriate antibiotics for infants with suspected LONS.Methods A retrospective chart review of all cases with LONS seen in the neonatal intensive care unit (NICU)of Yuying Children's Hospital of Wenzhou Medical College from January 1,2002 to December 31,2005 was conducted.All cases were selected based on the clinical presentation and at least one positive result of blood culture.The basic clinical characteristics and the results of blood culture and antimicrobial susceptibilities were analyzed.Results A total of 102 cases with LONS were identified.Among those 102 cases,80 were community acquired(infants admitted from home and the blood culture was done on admission)and 22 were hospital acquired (infants became sick while in the NICU and the blood culture was done prior to use of antibiotics).The clinical presentations were non-specific.Compared to the infants with community acquired LONS,infants with hospital acquired LONS were usually born more prematurely(mean gestational age 33±3 vs 39±2 wks,t=2.255,P＜0.01),with lower weight(mean weight 1.79±0.70 vs 3.23±0.67 kg,t=8.818,P＜0.01)and with younger age(mean age 12±6 vs 16±7 days,t=7.581,P＜0.05).Of the 102 csses,a total of 103 strains of bacteria were isolated.Among the pathogenic bacteria isolated,the most common were eoagulase-negative Staphylococcus(CoNS)(50/103,48.5%),followed by Klebsiella pneumoniae(16/103,15.5%).The main pathogens for community acquired LONS were Staphylococcus species and Escherichia coli.The most important pathogen responsible for hospital acquired LONS was KlebsieUa pneumoniae.Most(＞80%)of the Staphylococcus especially CoNS were resistant to common antibiotics such as penicillin,erythromyein and cefazolin.Significant numbers(6/9)of Staphylococcus aureus isolated were methicillin-resistant Staphylococcus aureus(MRSA).However,all of the Staphyloccus isolates were sensitive to vancomycin.Almost all(15/16)of the Klebsiella pneumoniae isolated were multidrug resistant due to production of extended-spectrum β-lactamases(ESBLs).They were sensitive only to a few antibiotics such as carbopenems,aminoglycosides and quinolones.There was also one strain of vancomycin-resistant Enterococcus(VRE).Furthermore,there was no a single case of late onset neonatal sepsis due to infection with group B Streptococcus(GBS).Conclusions The clinical manifestations of late onset neonatal sepsis are usually non-specific.GBS is not a significant pathogen responsible for community acquired LONS in the Wenzhou area.There are increasing numbers of multi-drug resistant bacterial species isolated from the newborn infants with late onset neonatal septicemia,which is most likely due the nonrestricted use of antibiotics in the hospitals as well as in the communities.A routine blood culture should be taken from any newborn infant who is suspected of LONS and empirical use of appropriate antibiotics should be initiated as soon as the blood specimen for culture has been drawn.To reduce the occurrence of multidrug resistant bacteria, the use of antibiotics especially the third generation cephalosporins in neonates should be restricted as much as possible.