脑室外引流术后并发颅内感染影响因素分析

目的：探讨脑室外引流术后并发颅内感染的影响因素。方法对105例经额脑室前角穿刺脑室外引流术患者的临床资料进行回顾性分析。结果在排除年龄、性别、手术耗时等干扰因素的情况下：（1）置管时间＞10 d者颅内感染率最高（16．0％），其次是≥7 d者（12．5％），＜7 d者最低（10．0％）。（2）单侧外引流颅内感染率低于双侧外引流（10．5％/16．7％）。（3）引流管在原切口的颅内感染率最高（23．1％），距原切口3 cm-5 cm的感染率最低（9．5％）。（4）未预防性应用抗生素的感染率最高（10．7％），术后3d鞘内注射感染率最低（4．5％）。结论脑室外引流术后并发颅内感染受影响因素众多，对患者进行全面的观察和治疗，可有效避免或减少颅内感染的发生。     

2011~2013年医院感染菌群分布及耐药状况分析

目的统计医院患者细菌感染菌群的变化以及耐药情况,为医院内感染管理和临床合理用药提供参考依据。方法常规培养分离临床标本,采用梅里埃公司的VITEK2全自动微生物分析仪,对标本进行细菌鉴定和药敏分析。药敏确证实验,采用美国临床检验室标准化委员会(Clinical and Laboratory Standards Institute,CLSI)推荐的纸片扩散法,进行确证实验。结果2011~2013年医院感染的细菌标本来源以痰液、分泌物和中段尿为主;且感染的主要细菌呈上升趋势,排在前五位的细菌分别是:大肠埃希菌、肺炎克雷伯菌、鲍曼不动杆菌、铜绿假单胞菌和金黄色葡萄球菌;常见的多重耐药菌,排前三位的是鲍曼不动杆菌、铜绿假单胞菌和大肠埃希菌,其在3年中的构成比有小幅度的增加;3年中革兰阴性杆菌(G-)耐药率大于70%的抗菌药物有:氨苄西林、头孢呋辛钠和头孢呋辛酯;革兰阳性球菌(G+)耐药率大于70%的抗菌药物有:青霉素G和红霉素。除4例粪肠球菌外,没发现其他耐万古霉素的菌株。结论细菌感染的标本来源以痰液为主。革兰阴性杆菌是医院感染的主要致病菌,呈每年递增的趋势,多重耐药菌株也不断上升,青霉素类药物已不适用于临床细菌感染的治疗;亚胺培南对大肠埃希菌和肺炎克雷伯有很高的敏感性。医院应高度重视感染的管理,加强抗菌药物应用的监管,减少细菌感染的爆发和流行,减少耐药菌株的增加。     

肺炎克雷伯菌对β-内酰胺类抗生素耐药性主决定因素的研究

目的了解肺炎克雷伯菌对β-内酰胺类抗生素耐药性及耐药性特点,并探究其主决定因素。方法对临床送检的痰液、咽拭子、气管分泌物等做细菌培养,根据药敏试验结果分为敏感菌株、泛耐药菌株、多重耐药菌株3种菌株。分析菌株β-内酰胺酶活性以及细胞外膜通透性的变化。结果与敏感菌株组β-内酰胺酶活性(12±6)U/mg比较,泛耐药菌株组β-内酰胺酶活性(253±36)U/mg,多重耐药菌株组β-内酰胺酶活性均明显增多,差异显著,有统计学意义(P<0.05)。而泛耐药菌株组β-内酰胺酶活性表达最高;与敏感菌株组细胞外膜通透性比较,泛耐药菌株组细胞外膜通透性、多重耐药菌株组细胞外膜通透性具有明显的阻碍作用,差异显著,有统计学意义(P<0.05)。而泛耐药菌株组细胞外膜通透性阻碍作用最强。结论β-内酰胺酶活性和细胞外膜通透性是肺炎克雷伯菌对β-内酰胺类抗生素耐药性的主决定因素。     

Comparative Study of Cefixime Alone Versus Intramuscular Ceftizoxime Followed by Cefixime in the Treatment of Urinary Tract Infections in Children

Abstract

Urinary tract infections (UTI) can cause acute morbidity and may result in severe problems, including hypertension and reduced renal function. Diagnosis of UTI is extremely important since prompt treatment may prevent damage. In the present study we compared the efficacy of oral cefixime to initial intramuscular ceftizoxime followed by cefixime for the treatment of UTI in children. Fifty-four children were studied. They were randomized to receive either oral cefixime 8 mg/kg/day for 10 days or initial intramuscular ceftizoxime (Cef?zox) 50 mg/kg twice a day for 2 days followed by oral cefixime for 8 days. Treatment groups were comparable regarding age, sex, clinical, and laboratory findings. Escherichia coli was isolated from 80% of patients. Repeat urine cultures were sterile within 24 hours in all children. Cure rates were comparable in both groups (92% vs 86% at the end of treatment). No serious adverse effects were observed. We concluded that oral cefixime is a safe and effective alternative treatment.     

An area-based study on intrapartum antibiotic prophylaxis for preventing group B streptococcus early-onset disease: advances and limitations

Introduction: The prevalence of maternal group-B-streptococcus (GBS) colonization and risk factors (RFs) for neonatal early-onset disease (EOD) in Europe are poorly defined. Large-scale information concerning adherence to recommendations for preventing GBS-EOD are lacking.

Materials and methods: This was a 3-month retrospective area-based study including all regional deliveries ≥35 weeks' gestation (in 2012). The sensitivity, specificity, positive and negative predictive values, odds ratio and receiver operating characteristic (ROC) curve for intrapartum antibiotic prophylaxis (IAP) among full-term and preterm deliveries and prolonged membrane rupture (PROM) were calculated.

Results: Among 7133 women, 259 (3.6%) were preterm (35–36 weeks' gestation). Full-term women were 6874, and 876 (12.7%) had at least 1?RF. Most women (6495) had prenatal screening and 21.4% (1390) were GBS positive.

IAP was given to 2369 (33.2%) women (preterm, n?=?166; full term, n?=?2203). Compared to full-term, preterm women were less likely to receive IAP when indicated (73.2% versus 90.3%, p?Conclusions: Large-scale prenatal screening and IAP are feasible. Women delivering preterm are less likely to receive IAP when indicated. Most unnecessary antibiotics are given in cases of PROM.     

New antibiotic strategies in patients with cirrhosis and bacterial infection

Early diagnosis and adequate empirical antibiotic treatment of bacterial infections in advanced cirrhosis is essential to improve outcomes given the high risk of developing severe sepsis, multiple organ failure and death. β-lactams and quinolones are nowadays frequently ineffective in nosocomial and healthcare associated infections, due to the increasing prevalence of multidrug resistant (MDR) bacteria reported across different geographical areas. Recent antibiotic exposure also increases the risk of developing MDR bacterial infections. Initial antibiotic strategies should therefore be tailored according to the presence or absence of risk factors of MDR bacteria and to the severity of infection and should consider the local epidemiology. Empirical treatment in the population at high risk of MDR bacterial infections requires the use of broad-spectrum antibiotics (carbapenems or tigecycline) and of drugs active against specific resistant bacteria (glycopeptides, linezolid, daptomycin, amikacin, colistin). Early de-escalation policies are recommended to prevent the spread of MDR bacteria in cirrhosis.     

Do antibiotics decrease implant failure and postoperative infections? A systematic review and meta-analysis

The purpose of this study was to systematically review and perform a comprehensive meta-analysis of the current literature to answer the following question: among patients receiving dental implants, does the use of antibiotics, when compared with a control group, reduce the frequency of implant failure and postoperative infection? A manual and electronic PubMed search of the literature was made to identify randomized controlled trials (RCTs) on the efficacy of antibiotics compared with a control group (not receiving antibiotics or receiving placebo). Four RCTs were included in the final review. These four RCTs grouped a total of 2063 implants and a total of 1002 patients. Antibiotic use significantly lowered the implant failure rate (P = 0.003), with an odds ratio of 0.331, implying that antibiotic treatment reduced the odds of failure by 66.9%. The number needed to treat (NNT) to prevent one patient from having an implant failure was 48 (95% confidence interval 31–109). In contrast, antibiotic use did not significantly reduce the incidence of postoperative infection (P = 0.754). Based on the results of this meta-analysis, and pending further research in the field, it can be concluded that there is evidence in favour of systematic antibiotic use in patients receiving dental implants, since such treatment significantly reduces implant failure. In contrast, antibiotic use does not exert a significant preventive effect against postoperative infection. Our recommendations for future research focus on the performance of large-scale RCTs to identify the best choice of antibiotic, timing of administration, and dose. Increased effort is also required to reach consensus and define the most effective antibiotic treatment protocol for patients who are allergic to beta-lactams and for those who are not.     

Structural basis for TetM-mediated tetracycline resistance

Ribosome protection proteins (RPPs) confer tetracycline resistance by binding to the ribosome and chasing the drug from its binding site. The current model for the mechanism of action of RPPs proposes that drug release is indirect and achieved via conformational changes within the drug-binding site induced upon binding of the RPP to the ribosome. Here we report a cryo-EM structure of the RPP TetM in complex with the 70S ribosome at 7.2-Å resolution. The structure reveals the contacts of TetM with the ribosome, including interaction between the conserved and functionally critical C-terminal extension of TetM and the decoding center of the small subunit. Moreover, we observe direct interaction between domain IV of TetM and the tetracycline binding site and identify residues critical for conferring tetracycline resistance. A model is presented whereby TetM directly dislodges tetracycline to confer resistance.