新生儿重症监护病房耐甲氧西林金黄色葡萄球菌定植率和危险因素分析

目的 分析NICU中耐甲氧西林金黄色葡萄球菌(MRSA)皮肤定植率和危险因素.方法 选取NICU收治新生儿1678例,其中男938例,女740例;日龄1～28 d,平均(5.9±6.4)d.使用无菌棉签采集新生儿鼻翼两侧和鼻腔底部标本,行金黄色葡萄球菌(SA)培养和鉴定.采用PCR法检测mecA基因以鉴定MRSA.统计SA和MRSA皮肤定植率,比较不同住院时间MRSA皮肤定植率的差异,分析MRSA皮肤定植与相关参数的相关性.结果 NICU中新生儿SA和MRSA皮肤定植率分别为21.10％(354/1678例)和3.69％ (62/1678例).随住院时间的延长(住院1、3、7d),新生儿MRSA皮肤定植率明显增加,差异具有统计学意义(P＜0.05),但住院7d和14 d MRSA皮肤定植率差异无统计学意义(P＞0.05).Logistic回归分析显示:胎龄、体质量和Apgar评分与MRSA皮肤定植率呈负相关,而手术或侵入性操作和抗生素使用与MRSA皮肤定植率呈正相关.结论 NICU新生儿MRSA皮肤定植率较高,住院7d内其定植率随住院时间延长而增加;MRSA皮肤定植与新生儿胎龄、体质量、Apgar评分、手术或侵入性操作和抗生素使用密切相关.     

Comparison of community-acquired methicillin-resistant <Emphasis Type="Italic">Staphylococcus</Emphasis><Emphasis Type="Italic">aureus</Emphasis> bacteremia to other staphylococcal species in a neonatal intensive care unit

Hospital acquired infections including staphylococcal species are common in neonatal intensive care units. Community-associated methicillin-resistant Staphylococcus aureus (CA-MRSA) was recently observed in our unit. The clinical and laboratory characteristics of all neonates with Staphylococcus aureus bacteremia during an 11-year period were retrospectively reviewed. Three groups of patients were compared: 1. Patients with CA-MRSA defined as MRSA-resistant only to beta-lactams, but sensitive to all other antibiotic groups and carried SCCmec IV. 2. Patients with multi-drug-resistant (MDR)-MRSA and 3. Patients with MSSA (methicillin-sensitive S. aureus). Forty-three neonates with documented S. aureus bacteremia were included. Of these 41 were preterm babies. Eleven infants had CA-MRSA, 20 had MDR-MRSA and 12 had MSSA bacteremia, the Panton-Valentine-Leukocidine gene (pvl-gene) was not present in any of these strains. Risk factors, clinical manifestations and laboratory tests were similar in all three groups studied. Although neonates infected with CA-MRSA were more premature and had more related diseases, the mortality rate was similar in all groups (9.1% in the CA-MRSA group). Skin infections, osteomyelitis or pneumatocele were not observed more frequently in the CA-MRSA group. We did not find significant differences in risk factors or outcomes in neonates in the three groups. One possible explanation for this observation is that the CA-MRSA outbreak strain did not contain the pvl-gene, which has been suggested to be a significant virulence factor.     

Outpatient Management of Community-associated Methicillin-resistant Staphylococcus aureus Skin and Soft Tissue Infection

During the past decade, there has been a dramatic increase in the number of patients presenting with skin and soft tissue infections in the outpatient setting. The predominant causative bacterium for these infections has recently been identified as community-associated methicillin-resistant Staphylococcus aureus (CA-MRSA). It is estimated that nearly 80% of infections caused by CA-MRSA manifest as skin and soft tissue infections which are of mild to modest severity. However, invasive disease and fatal illness has been reported among otherwise healthy adults and children. The rapid evolution of CA-MRSA presents a unique challenge for pediatric health care providers. As such, it is critical to raise awareness regarding the epidemiology, microbiology, and evidence-based treatment options for treating skin and soft tissue infections in the age of CA-MRSA. The aims of this article include discussion regarding the epidemiology, microbiology, and evidence-based management of CA-MRSA as well as publication of a more relevant one-page evidence-based treatment flow diagram and antimicrobial prescribing table for health care providers practicing in the ambulatory care setting.     

Community-associated methicillin-resistant Staphylococcus aureus in Indigenous communities in Canada

Community-associated methicillin-resistant Staphylococcus aureus (CA-MRSA) infections have emerged as a significant issue in some Indigenous communities (including First Nations, Inuit and Métis) in Canada. Primarily associated with skin and soft-tissue infections, this organism can also result in significant morbidity and mortality. Canadian and American guidelines for managing CA-MRSA infections have been published. The specific epidemiology, microbiology and susceptibility patterns, and the social/environmental circumstances of CA-MRSA infections in Indigenous communities need to be considered for strategies to reduce transmission. While reducing household crowding and improving in-home potable water supply are optimal strategies to reduce the impact of this illness, implementing Canadian guidelines along with increased prevention strategies are recommended as interim measures.     

Elimination of methicillin-resistant Staphylococcus aureus from a neonatal intensive care unit after hand washing with triclosan

Abstract Evaluating hand wash products in terms of user acceptability and effectiveness against methicillin-resistant Staphylococcus aureus (MRSA) has been part of a long-term strategy to eliminate endemic MRSA from the neonatal intensive care unit at the Royal Women's Hospital (Brisbane). Following the introduction of a new hand wash disinfectant (triclosan 1% wt/vol), new cases of MRSA colonization were monitored for 12 months. In addition, the use of antibiotics, the incidence of multi-resistant Gram-negative cultures and neonatal infections were noted. No changes were made to any procedures or protocols during the trial. All babies colonized with MRSA had been discharged from the nursery within 7 months of the introduction of triclosan and in the subsequent 9 months no new MRSA isolates had been reported. Reduction in the use of vancomycin has resulted in a cost saving of approximately $A17000. The total number of Gram-negative isolates has not increased, although Pseudomonas aeruginosa is now reported more often. Compared with the previous 12 months. fewer antibiotics were prescribed and fewer nosocomial infections recorded ( P <0.05).     

金黄色葡萄球菌感染住院患儿鼻部携带菌株的研究

目的 观察金黄色葡萄球菌(简称金葡菌)感染的住院患儿鼻部携带菌株与金葡菌感染之间的相关关系。方法 以56 例金葡菌感染的住院患儿为研究对象,采集鼻拭子标本进行培养,检测患儿的金葡菌鼻部携带率,并采用PCR 方法分别检测临床菌株和鼻部携带菌株的mecA 耐药基因和PVL 毒力基因。结果 56例金葡菌感染患儿中,22 例(39%)鼻部携带金葡菌,携带患儿以婴儿为主(18 例)。50%(11/22)携带患儿既往1 年内有住院史。在感染株中,耐甲氧西林金葡菌(MRSA)占29%(16/56);在携带株中,MRSA 占32%(7/22)。PCR 检测携带患儿的临床感染菌株和鼻部携带菌株mecA 阳性结果完全一致,可一一对应;90%(4/5)的PVL 阳性鼻部携带菌株可以与临床感染菌株一一对应,且均为MRSA 菌株。结论 鼻部定植是金葡菌感染的潜在危险因素。医院内传播可能是导致金葡菌鼻部携带,最终导致其感染的重要潜在危险。金葡菌鼻部携带菌株与感染菌株可能具有同源关系,需要进一步通过多位点序列分型明确其同源关系。     

儿童金黄色葡萄球菌脓毒症抗生素治疗现状分析

目的 回顾性分析金黄色葡萄球菌脓毒症患儿经验性抗生素治疗现状,探讨治疗模式对其预后的影响。方法 将2014年1月至2017年8月收治的78例金黄色葡萄球菌脓毒症患儿,依据血培养报告金黄色葡萄球菌生长前经验性首选抗生素治疗类型分为碳青霉烯类治疗组（n=16）、β-内酰胺类治疗组（n=37）、万古霉素治疗组（n=15）、万古霉素+β-内酰胺类治疗组（n=10）。收集各组患儿的一般情况、基础疾病、急性生理功能与慢性健康状况评分系统Ⅱ（APACHE Ⅱ）、免疫抑制剂使用史、甲氧西林耐药性及预后资料,进行回顾性分析。采用logistic回归探讨经验性抗生素治疗方案对金黄色葡萄球菌脓毒症患儿临床疗效及预后的影响。结果 各组患儿一般情况、基础疾病、免疫抑制剂使用史、APACHE Ⅱ评分、院内感染、MRSA检出率比较差异无统计学意义（P > 0.05）。四组间脓毒性休克、院内死亡率比较差异有统计学意义（P < 0.05）,其中碳青霉烯类治疗组脓毒性休克、院内死亡率均最高（分别为69%、50%）。多因素logistic回归分析结果提示,经验性抗生素治疗类型是金黄色葡萄球菌脓毒症患儿发生脓毒性休克和院内死亡的独立危险因素（P < 0.05）;APACHE Ⅱ评分≥ 15是金黄色葡萄球菌脓毒症患儿发生脓毒性休克的独立危险因素（P < 0.05）;与使用万古霉素治疗组相比,碳青霉烯类治疗组发生脓毒性休克和院内死亡的风险高（P < 0.05）。结论 不恰当的经验性使用抗生素治疗可能导致儿童金黄色葡萄球菌脓毒症预后不佳。临床疑诊金黄色葡萄球菌脓毒症患儿,不建议经验性使用碳青霉烯类抗菌药物治疗。     

Staphylococcus aureus epidemic in a neonatal nursery: a strategy of infection control

The risk of nosocomial infection due to Staphylococcus aureus in fullterm newborns is higher under hospital conditions where there are overcrowded nurseries and inadequate infection control techniques. We report on an outbreak of skin infection in a Maternity Nursery (May 21, 2000) and the measures undertaken to bring the epidemic under control. These measures included: separating neonates already present in the nursery on August 23, 2000 from ones newly arriving by creating two different cohorts, one of neonates born before this date and one of neonates born later; restricting healthcare workers caring for S. aureus- infected infants from working with non-infected infants; disallowing carrier healthcare workers from caring for patients; introducing contact and droplet precautions (including the routine use of gowns, gloves, and mask); ensuring appropriate disinfection of potential sources of contamination. A representative number of isolates were typed by genomic DNA restriction length polymorphism analysis by means of pulsed-field gel electrophoresis (PFGE). Among the 227 cases of skin lesions, microbiological laboratory analyses confirmed that 175 were staphylococcal infections. The outbreak showed a gradual reduction in magnitude when the overcrowding of the Nursery was reduced by separating the newborns into the two different Nurseries (two cohorts). The genotyping of the strains by PFGE confirmed the nurse-to-newborn transmission of S. aureus. The measures adopted for controlling the S. aureus outbreak can, in retrospect, be assessed to have been very effective.     

新生儿重症监护室血培养233株病原菌分布及耐药性分析

目的 研究新生儿重症监护室(neonatal intensive care unit,NICU)血培养阳性的脓毒症患儿的病原菌分布及耐药情况,为临床合理使用抗生素提供依据.方法 回顾性分析2009年1月至2011年7月广东医学院附属医院NICU 1450例新生儿的1450份血培养结果及药敏结果.结果 1450份血培养标本共分离病原菌9种233株,总阳性率为16.1％.其中革兰阳性球菌93株,以凝固酶阴性葡萄球菌占优势,其次为金黄色葡萄球菌;革兰阴性杆菌103株,以肺炎克雷白杆菌居多,其次为大肠埃希菌、鲍曼不动杆菌;真菌37株,以念珠菌为主.革兰阳性球菌对万古霉素、利奈唑胺及替考拉宁敏感性高,对青霉素、苯唑西林及β-内酰胺酶抗生素耐药性达95％以上;革兰阴性杆菌对左氧氟沙星、亚胺培南及美罗培南敏感;真菌以念珠菌为主,对抗真菌药物普遍敏感.结论 凝固酶阴性葡萄球菌、肺炎克雷白杆菌、大肠埃希菌等是NICU中新生儿脓毒症最常见的几种病原菌,耐药性高,临床医生应根据细菌鉴定及药敏试验选择敏感药物治疗,且真菌感染不可忽视,值得关注.     

肾功能亢进对耐甲氧西林金黄色葡萄球菌感染患儿万古霉素血药浓度及治疗效果的影响分析

目的 研究肾功能亢进（ARC）对万古霉素治疗儿童耐甲氧西林金黄色葡萄球菌（MRSA）感染时的血药浓度、细菌学疗效及临床疗效的影响。方法 回顾性研究2013年1月至2017年7月期间因明确MRSA感染使用万古霉素,并进行血药浓度监测的60例危重患儿的病例资料,根据肾小球滤过率（eGFR）分为ARC组（n=19）和肾功能正常组（n=41）,对两组患儿在万古霉素使用、血药浓度及治疗效果等方面进行统计学比较分析。结果 ARC组的年龄主要分布在1~12岁,其体重和体表面积明显大于肾功能正常组（P < 0.05）。ARC组初始万古霉素血药谷浓度明显低于肾功能正常组,且ARC组达有效血药谷浓度（10~20 mg/L）比例低于肾功能正常组（P < 0.05）。两组在细菌学疗效评价和临床疗效评价方面比较差异均无统计学意义（P > 0.05）,但ARC组的儿童重症监护室（PICU）住院时间及总住院时间明显长于肾功能正常组（P < 0.05）。结论 ARC明显降低MRSA感染患儿的万古霉素血药谷浓度,延长PICU住院时间及总住院时间。临床上应注意对ARC患儿施行个体化给药治疗。     

Antimicrobial use for treatment of healthcare-associated infections and bacterial resistance in a reference neonatal unit

ObjectiveThe use of broad-spectrum antimicrobials, such as third and fourth-generation, are responsible for emergence of multidrug-resistant microorganisms in neonatal units. Furthermore, antimicrobial daily doses are not standardized in neonatology. This study aimed to investigate the association between the use of antimicrobial broad spectrum to bacterial sensitivity profile in a referral unit of neonatal progressive care.MethodsThis is a cohort study conducted in a referral neonatal progressive care unit from January 2008 to December 2016. The data of all hospitalized neonates was collected daily. The infection criteria used were the standardized national criteria, based on definitions of Center for Diseases Control and Prevention. In this study, the use of antimicrobials was evaluated as antimicrobial-day (ATM-day) and the ratio of multidrug-resistant microorganisms per 1000 ATM-day of broad spectrum was also calculated. The study was approved by the Institutional Review Board of the Universidade Federal de Minas Gerais (ETIC 312/08 e CAAE 58973616.2.0000.5149).ResultsFrom 2008 to 2016, 2751 neonates were hospitalized, corresponding to 60,656 patient-days. The ratio of multidrug-resistant microorganisms per 1000 ATM-day of broad spectrum was 1,3 in the first period and 4,3 in the second period (p = 0,005).ConclusionIt was observed that use of broad-spectrum antimicrobials, especially those with coverage for Gram-negative bacteria, was associated with an increase of multidrug-resistant bacteria.     

Transmission of Panton-Valentine leukocidin-positive Staphylococcus aureus between patients with cystic fibrosis

Panton-Valentine leukocidin-producing Staphylococcus aureus is an emerging pathogen world-wide, causing necrotizing lung infections in otherwise healthy individuals. We describe 2 episodes of patient-to-patient transmission of Panton-Valentine leukocidin-producing S. aureus, resulting in acute, life-threatening pulmonary complications in patients with cystic fibrosis. Appropriate infection control measures may be warranted to prevent similar episodes.     

灾害背景下NICU的应急准备方案

由于对仪器设备的特殊需求,新生儿在灾害中极易受到更大伤害。新生儿重症监护病房(NICU)应尽可能为各种灾害做好准备。应急准备方案可保证NICU高效的灾害应对能力。新生儿灾害救援应根据实际情况做决策,如现有设备、药物、人员配备等。灾害应急准备中应包括伦理问题的解决方案,还应考虑灾害后家属及救援人员的心理需求。     

儿童肺炎链球菌脑膜炎的临床特点及耐药性分析

目的分析儿科住院患儿肺炎链球菌(SP)脑膜炎的临床特征,同时对培养出的SP菌株进行抗菌药物耐药性分析,以帮助临床早期诊断,合理选用抗菌药物。方法回顾性分析2008年9月至2014年3月收治的14例SP脑膜炎患儿的临床资料并进行耐药性分析。结果 14例SP脑膜炎患儿中,高热13例(93%),抽搐9例(64%),合并败血症7例(50%)。白细胞计数增高11例(79%),CRP增高10例(71%)。所有患儿脑脊液有核细胞计数增高,分类均以中性粒细胞为主,9例(64%)患儿脑脊液蛋白定量结果 1 000 mg/d L。经治疗后10例(71%)患儿痊愈,2例(14%)患儿有后遗症,2例(14%)患儿死亡。SP对青霉素、红霉素、克林霉素、四环素和磺胺耐药率高,均高于60%,对阿莫西林耐药率较低(7%),未发现对万古霉素、氯霉素、左旋氧氟沙星耐药菌株。结论实验室辅助检查指标对于区分SP脑膜炎和其他病原菌引起的脑膜炎无特异性。SP对儿科临床常用抗菌药物耐药情况严重,因此对SP的耐药情况应进行检测,以指导临床用药。     

Relatedness of strains of methicillin-resistant coagulase-negative Staphylococcus colonizing hospital personnel and producing bacteremias in a neonatal intensive care unit.

The emergence of methicillin-resistant coagulase-negative Staphylococcus as a major bacterial pathogen in neonatal intensive care units has stimulated interest in the epidemiology of spread of the organism. During a 12-month "epidemic" of bacteremias with methicillin-resistant coagulase-negative Staphylococcus we compared the characteristics of bacteremic and personnel nasally-carried strains by traditional and biomolecular methods. Sixty-two percent of neonatal intensive care unit nurses were colonized with methicillin-resistant coagulase-negative Staphylococcus with similar speciation to bacteremic strains. Inspection of plasmid profiles revealed a moderate degree of similarity between bacteremic and colonizing strains although genomic DNA restriction patterns showed diversity. Ribotype patterns were highly conserved (90%) in personnel strains. A 2.6-kilobase plasmid DNA probe hybridized to similarly sized plasmids and larger plasmids in one-half of the strains. We hypothesize that related methicillin-resistant strains may be transferred among personnel and neonates in the neonatal intensive care unit. Epidemiologic studies of coagulase-negative staphylococci should consider multiple molecular techniques to relate strains.