Effectiveness of Antimicrobial Peptide Immobilization for Preventing Perioperative Cornea Implant-Associated Bacterial Infection

Titanium (Ti) is a promising candidate biomaterial for an artificial corneal skirt. Antimicrobial peptide (AMP) immobilization may improve the bactericidal effect of the Ti substrate. In this study, we tested the bactericidal efficacy of a functionalized Ti surface in a rabbit keratitis model. A corneal stromal pocket was created by a femtosecond laser. The Ti films were then inserted into the pocket, and Staphylococcus aureus or Pseudomonas aeruginosa was inoculated into the pocket above the implant films. The corneas with Ti-AMP implants were compared with the corneas implanted with unprotected Ti by slit lamp observation and anterior segment optical coherence tomography (AS-OCT). Inflammatory responses were evaluated by bacterium counting, hematoxylin-eosin staining, and immunostaining. There was a lower incidence and a lesser extent of infection on rabbit corneas with Ti-AMP implants than on those with unprotected Ti implants. The bactericidal effect of AMP against S. aureus was comparable to that of postoperative prophylactic antibiotic treatment; hence, SESB2V AMP bound to the Ti implant provided functional activity in vivo, but its efficacy was greater against S. aureus than against P. aeruginosa. This work suggests that SESB2V AMP can be successfully functionalized in a rabbit keratitis model to prevent perioperative corneal infection.     

Antimicrobial Properties of 8-Hydroxyserrulat-14-en-19-oic Acid for Treatment of Implant-Associated Infections

Treatment options are limited for implant-associated infections (IAI) that are mainly caused by biofilm-forming staphylococci. We report here on the activity of the serrulatane compound 8-hydroxyserrulat-14-en-19-oic acid (EN4), a diterpene isolated from the Australian plant Eremophila neglecta. EN4 elicited antimicrobial activity toward various Gram-positive bacteria but not to Gram-negative bacteria. It showed a similar bactericidal effect against logarithmic-phase, stationary-phase, and adherent Staphylococcus epidermidis, as well as against methicillin-susceptible and methicillin-resistant S. aureus with MICs of 25 to 50 μg/ml and MBCs of 50 to 100 μg/ml. The bactericidal activity of EN4 was similar against S. epidermidis and its Δica mutant, which is unable to produce polysaccharide intercellular adhesin-mediated biofilm. In time-kill studies, EN4 exhibited a rapid and concentration-dependent killing of staphylococci, reducing bacterial counts by >3 log₁₀ CFU/ml within 5 min at concentrations of >50 μg/ml. Investigation of the mode of action of EN4 revealed membranolytic properties and a general inhibition of macromolecular biosynthesis, suggesting a multitarget activity. In vitro-tested cytotoxicity on eukaryotic cells was time and concentration dependent in the range of the MBCs. EN4 was then tested in a mouse tissue cage model, where it showed neither bactericidal nor cytotoxic effects, indicating an inhibition of its activity. Inhibition assays revealed that this was caused by interactions with albumin. Overall, these findings suggest that, upon structural changes, EN4 might be a promising pharmacophore for the development of new antimicrobials to treat IAI.     

预防肾病综合征感染的循证医学证据

目的：运用循证医学原理评价目前预防肾病综合征感染的各种干预措施的有效性及安全性，为临床循证实践提供依据。方法：检索Cochrane临床对照试验数据库、MEDLINE、EMBASE和中国生物医学献数据库。结果：共检索出符合纳入标准的献11篇，包括RCT、描述性临床研究、传统综述，未检出系统评价或Meta分析献。所获献中，预防肾病综合征感染的措施涉及静脉滴注丙种球蛋白(IgG)、静脉应用胸腺肽、中药辅助治疗、肺炎链球菌疫苗接种的献，预防性应用抗生素或阿昔洛韦，以及口服拉米夫定。结论：目前，评价预防肾病综合征感染的措施的有效性及安全性的循证医学证据非常有限，研究质量较差。各种预防肾病综合征感染的措施的潜在疗效及安全性尚有待严格设计的随机双盲安慰剂对照试验或系统评价加以证实。     

Back to Basics: Preventing Surgical Site Infections

A surgical site infection (SSI) is an unintended and oftentimes preventable consequence of surgery. There is a significant amount of literature related to preventing SSIs, and it is up to practitioners in each care setting to review the evidence and work together to implement SSI prevention measures, such as nasal decolonization, antibiotic prophylaxis, preoperative showers, preoperative oxygen supplementation, and antimicrobial sutures. In addition, practitioners can follow several recommendations to reduce the risk of SSIs, including following proper hand hygiene practices; wearing clean, facility-laundered scrub attire; following a surgical safety checklist; and speaking up when a break in sterile technique is witnessed. The benefits of preventing SSIs are preventing patient mortality and decreasing the burden that SSIs pose on the national health care system. It is up to health care leaders to drive and support SSI prevention initiatives.     

医护合作小组活动在预防重症监护患者导管相关感染中的作用

目的探讨医护合作小组活动在预防重症监护患者导管相关感染中的作用。方法 2011年1月～12月在重症监护室开展医护合作小组活动,随机抽查100例(A组)符合入选条件的患者,监测导管使用与患者导管相关性感染发生情况,并与2010年同期100例(B组)符合入选条件的患者进行对照分析。结果 A组中心静脉导管、呼吸机通气导管、导尿管使用率分别为81.13%、42、71%、60.60%,均低于B组中心静脉导管、呼吸机通气导管、导尿管使用率分别为82.95%、56.41%、81.28%,除中心静脉导管外,呼吸机通气导管与导尿管使用率两组比较有显著性差异(P0.01);A组中心静脉导管、呼吸机通气导管、导尿管相关性感染率分别为0.52‰、3.97‰、3.48‰,均低于B组中心静脉导管、呼吸机通气导管、导尿管感染率分别为1.96‰、7.94‰、6.01‰,两组比较无显著性差异(P0.05)。结论开展医护合作小组活动,有利于提高预防导管相关性感染各项措施执行力,降低各种导管使用率和导管相关性感染率。     

大蒜浸出液预防重症患者口腔真菌感染的疗效观察

目的：探讨大蒜浸出液对预防重症患者口腔真菌感染的作用。方法：对287例重症患者采用大蒜浸出液作为护理液进行口腔护理和对照组临床资料进行分析。结果：阳性发生率对照组为21.93% 实验组为6.62%,两组比较,2χ=27,P〈0.01。结论：大蒜浸出液预防口腔真菌感染,疗效显著,毒副作用低,值得推广。     

单剂量环丙沙星加甲硝唑预防前列腺穿刺活检术后感染的临床观察

【目的】评价口服单剂量抗生素在经直肠前列腺穿刺活检术中预防感染的临床效果。【方法】192例接收经直肠超声引导13点前列腺系统穿刺活检术患者，随机分为3组。A组62例，口服安慰剂（维生素C）0．2g，每天2次，共3d；B组64例，13服单剂量环丙沙星0．5g加甲硝唑0．4g，1次；C组66例，口服环丙沙星0．5g加甲硝唑0．4g每天2次，共3d；所有患者均在活检后48h进行尿培养，发热者再进行血培养检查。【结果】A、B、C三组患者感染性并发症的发生率依次为11．3％（7／62），3．1％（2／64），3．0％（2／66）；A组明显高于B组和C组（P〈0．01），而B、C两组间感染性并发症的发生率差异无显著性（P〉0．05）。【结论】应用恰当的单剂量抗生素预防经直肠前列腺穿刺活检术中的感染是有效的。     

Prospective Evaluation of Topical Antibiotics for Preventing Infections in Uncomplicated Soft-tissue Wounds Repaired in the ED

Objective: To determine differences in infection rates among uncomplicated, repaired wounds managed with: topical bacitracin zinc (BAC); neomycin sulfate, bacitracin zinc, and polymyxin B sulfate combination (NEO); silver sulfadiazine (SIL); and petrolatum (PTR). Methods: This was a prospective, randomized, double-blind, placebo-controlled study conducted at a military community hospital with an emergency medicine residency program. Patients were enrolled if they: presented to the ED within 12 hours of injury and did not have puncture wounds, allergies to the agents used, or a history of immunocompromise; were not receiving antibiotics, chemotherapy, or steroids at the time of presentation; had not taken antibiotics within the preceding seven days; did not have an underlying fracture; and were not pregnant as determined by history. Local anesthetics without epinephrine and high-pressure irrigation with normal saline were used for all the patients. Wound scrubbing, debridement, and polyglactin subcutaneous (SQ) suture placement were carried out when necessary. Interrupted simple sutures using a monofilament, nonabsorbable material were used for skin closure. Numbered, randomized vials were given to all patients, with standardized instructions to inspect, clean, and redress their wounds three times a day. The wounds were evaluated for clinical infection at the time of follow-up. Results: Among the groups, there was no difference in patient ages; gender; wound location, type, length, or depth; time elapsed from injury to ED treatment; number of wounds scrubbed or necessitating debridement; number of SQ and cutaneous sutures used; and rate of compliance with returning the used vial of dispensed topical agent. The wound infection rates for the treatment groups were: BAC, six of 109 (5.5%); NEO, five of 110 (4.5%); SIL, 12 of 99 (12.1%); and PTR, 19 of 108 (17.6%) (p = 0.0034). Conclusion: The use of topical antibiotics resulted in significantly lower infection rates than did the use of a petrolatum control. BAC and NEO had the lowest wound infection rates.     

凝固酶阴性葡萄球菌感染

凝固酶阴性葡萄球菌（CNS）首先被Pasteur和Ogston在1880年鉴定,并最初命名为白色葡萄球菌,该菌属因不产生凝固酶而得名。到目前为止,已有超过40余种被鉴定的凝固酶阴性的葡萄球菌属。该病原体一般存在于健康人群的皮肤和黏膜上,因为一般很少引起感染,所以培养结果经常被临床医师认为是污染。然而,近年来CNS感染逐年增高且越来越多的被认为可以导致严重的临床感染。本综述包括该病原菌感染的临床表现,流行病学以及感染导管的处理。