Surgical Helmets Used During Total Joint Arthroplasty Harbor Common Pathogens: A Cautionary Note

BackgroundThe use of personal-protection surgical helmet/hood systems is now a part of the standard surgical attire during arthroplasty in North America. There are no protocols for the disinfection of these helmets.MethodsThis is a prospective, single-center, observational study. Helmets worn by 44 members of the surgical team and foreheads of 44 corresponding surgical personnel were swabbed at three distinct time points. In addition, 16 helmets were treated with hypochlorite spray to determine if pathogens could be eliminated. Swabs obtained were processed for culture and next-generation sequencing (NGS).ResultsOf the 132 helmet samples, 97 (73%) yielded bacteria on culture and 94 (71%) had evidence of bacterial–deoxyribonucleic acid (DNA) on NGS. Of the swabs sent for bacterial identification at the three time points, at least one from each helmet was positive for a pathogen(s). Of the 132 forehead samples, 124 (93%) yielded bacteria on culture and 103 (78%) had evidence of bacterial-DNA on NGS. The most commonly identified organism from helmets was Cutibacterium acnes (86/132) on NGS and Staphylococcus epidermidis (47/132) on culture. The most commonly identified organism from the foreheads of surgical personnel was Cutibacterium acnes (100/132) on NGS and Staphylococcus epidermidis (70/132) on culture. Sanitization of helmets was totally effective; no swabs taken the following morning for culture and NGS identified any bacteria.ConclusionThis study demonstrates that surgical helmets worn during orthopedic procedures are contaminated with common pathogens that can potentially cause surgical site infections. The findings of this study should at the minimum compel us to develop protocols for the disinfection of these helmets.     

Outbreak of Burkholderia cepacia complex bacteremia in a chemotherapy day care unit due to intrinsic contamination of an antiemetic drug

Background: In the end of 2009, a large number of patients with cancer undergoing chemotherapy at the day care unit of a private hospital in Mumbai, India developed Burkholderia cepacia complex (BCC) blood stream infection (BSI). Objective: The objectives were to identify the source of the outbreak and terminate the outbreak as rapidly as possible. Materials and Methods: All infection control protocols and processes were reviewed. Intensive training was started for all nursing staff involved in patient care. Cultures were sent from the environment (surfaces, water, air), intravenous fluids, disinfectants and antiseptics and opened/unopened medication. Results: A total of 13 patients with cancer with tunneled catheters were affected with BCC BSI. The isolates were of similar antimicrobial sensitivity. No significant breach of infection control protocols could be identified. Cultures from the prepared intravenous medication bags grew BCC. Subsequently, culture from unused vials of the antiemetic granisetron grew BCC, whereas those from the unopened IV fluid bag and chemotherapy medication were negative. On review, it was discovered that the outbreak started when a new brand of granisetron was introduced. The result was communicated to the manufacturer and the brand was withdrawn. There were no further cases. Conclusions: This outbreak was thus linked to intrinsic contamination of medication vials. We acknowledge a delay in identifying the source as we were concentrating more on human errors in medication preparation and less on intrinsic contamination. We recommend that in an event of an outbreak, unopened vials be cultured at the outset.     

An XPS and SEM evaluation of six chemical and physical techniques for cleaning of contaminated titanium implants

The purpose of the present study was to analyse clinically failed and retrieved implants prior to and after cleaning by means of scanning electron microscopy (SEM) and X-ray induced photoelectron spectroscopy (XPS) as compared to unused controls. Six different chemical and physical techniques for cleaning of contaminated titanium implants were evaluated: 1) rinsing in absolute ethanol for 10 min, 2) cleaning in ultrasonic baths containing trichloroethylene (TRI) and absolute ethanol, 10 min in each solution, 3) abrasive cleaning for 30 s, 4) cleaning in supersaturated citric acid for 30 s, 5) cleaning with continuous CO2-laser in dry conditions at 5 W for 10 s, 6) cleaning with continuous CO2-laser in wet conditions (saline) at 5 W for 10 s. SEM of failed implants showed the presence of contaminants of varying sizes and XPS showed almost no titanium but high carbon signals. XPS of unused titanium implants showed lower levels of titanium as previously reported, probably due to contamination of carbon which increased with time in room air. Cleaning of used implants in citric acid followed by rinsing with deionized water for 5 min followed by cleaning in ultrasonic baths with TRI and absolute ethanol gave the best results with regard to macroscopical appearance and surface composition. However, as compared to the unused implants the results from an element composition point of view were still unsatisfactory. It is concluded that further development and testing of techniques for cleaning of organically contaminated titanium is needed.     

抗莱氏支原体单克隆抗体的研制

通过细胞融合技术，筛选出ＭＡＬ－１和ＭＡＬ－２两株抗莱氏支原体（Ａ．Ｌａｉｄｌａｗｉｉ，Ａ．Ｌ）单克隆抗体（单抗）。通过ＳＤＳ－ＰＡＧＥ和Ｗｅｓｔｅｒｎ印迹法测得单抗相对应的抗原分子量均为６７．４６ｋｕ。用间接免疫荧光法（ＩＦＡ）检测，单抗与细胞培养中另外３种常见污染的支原体和呼吸道肺炎支原体无交叉反应。将单抗用于检测支原体污染的细胞培养物，结果表明，此单抗能特异性地检出莱氏支原体。故可用其推断支原体污染途径，便于制定防治措施。     

奈替米星体液浓度测定的方法学研究

通过对国产硫酸奈替米星注射后人体血尿中药物浓度测定，建立了奈替米星体液浓度测定的微生物法，该方法的检测限为０．０３７５～０．０７５１μｇ，最低检测浓度为０．２５～０．５μｇ／ｍｌ，回收率为８８．８％±３．６３％～９８％±１４．４０％，重复性试验相对标准差为２．２２％～５．３４％；并对１０例健康受试者用药后血标本１００余份进行了微生物法测定和高压液相色谱法测定，对两种方法测定结果的比较发现：微生物法测定的血药浓度明显高于ＨＰＬＣ法（Ｐ＜０．０１），而ＨＰＬＣ法由于需复杂的样品预处理和特殊的色谱条件，测定的血药浓度较低，回收率仅７１．９８％～７６．９６％。不过，两种方法测定结果的相关性较好。本研究结果提示：微生物法测定奈替米星体液浓度简便、易操作、结果准确可信，适用于体液药物浓度测定。     

Microbial aspects of home enteral nutrition–a discussion

Factors that might contribute to the microbial contamination of enteral feeds prepared and administered in the home are reviewed and the significance of this contamination discussed. Numbers, types and sources of micro-organisms, and possible routes for contamination of home enteral feeds, are outlined and the role of cleaning and disinfection in reducing the microbial load is discussed. Some preliminary guidelines are suggested for the handling of enteral feeds in the home.     

What is the HACCP (hazard analysis critical control point) approach and how can it be applied to enteral tube feeding?

The HACCP (hazard analysis critical control point) concept is now widely applied in the food industry and provides a structured and critical approach to the identification and control of hazards that may affect food safety. It has shifted the emphasis for control from retrospective end-product testing to the effective control of raw materials and key processing operations.
This paper discusses how the HACCP approach can be applied to enteral feeding. This involves each unit assembling a multidisciplinary team of personnel involved in enteral feeding. This team will then carry out a detailed analysis of the process from selection of ingredients and feeding systems through to consumption of the feed by the patient by constructing a flow chart that relates specifically to each unit. They can then identify and assess the hazards associated with the handling of the product at each stage in the process. This will enable them to identify the points where control over an identified hazard can be achieved (critical control points, CCP) such as quality of ingredients, design of administration systems, preparation and distribution of the feeds and the procedures involved in the assembly and manipulation of the systems. Control and monitoring procedures can then be specified and implemented at relevant stages in the process. The major strengths of the HACCP procedure are that it entails a team effort from key personnel involved in the full range of activities associated with the product and each detailed analysis is specific to each unit's practices and resources and can be continually reviewed and modified in response to changing circumstances.     

车载苯胺泄漏事故造成水井污染的监测分析

2003年12月30日一辆装载7.28t苯胺的槽车从宁波开往温州的路上在甬台温高速公路温岭市境内翻车,造成5.3t左右的苯胺泄漏在高速公路旁的环境中,除少量的液体被清除外,绝大部分渗入地下,造成了水井污染.从12月31日开始我们对周围的水井开展了监测,现将监测结果分析如下:     

上海地区学生午餐营养及供应链状况研究

目的 了解上海地区学生午餐营养及供应链状况，为改善学生午餐营养状况，保障食品供应安全提供参考。方法 分析上海市学生午餐的营养、卫生、供应链、加工工艺等状况，采用定期抽检的方法，应用SNHAS对营养素、食品安全、感官进行综合评价。结果 各单位样本综合评价均合格，其中热量、蛋白质、脂肪均能达到或超过DRIs供给量的要求，但矿物质中Ca(仅为AI的32％)、视黄醇当量(仅为AI的57％)供给量较低。对供应链及卫生状况的分析表明，大型企业对各个环节控制严格，产品质量较好，但也存在保存时间过长等问题。结论 应进一步完善供应体系，建立高效的质量控制体系，推广营养配膳系统。     

Quantifying the blood oxygenation level dependent effect in cerebral blood volume-weighted functional MRI at 9.4T.

In cerebral blood volume (CBV)-weighted functional MRI (fMRI) employing superparamagnetic contrast agent, iron dose and blood oxygenation level dependent (BOLD) contamination are two important issues for experimental design and CBV quantification. Both BOLD and CBV-weighted fMRI are based upon the susceptibility effect, to which spin-echo and gradient-echo sequences have different sensitivities. In the present study, CBV-weighted fMRI was conducted using spin-echo and gradient-echo sequences at 9.4T by systematically changing the doses of contrast agent. Results suggest that BOLD contamination is a significant component in CBV-weighted fMRI at high field, particularly when relatively low dose of contrast agent is administered. A mathematical model was developed to quantify the extravascular (EV) BOLD effect. With a TE of 35 ms, the EV BOLD effect was estimated to account for 76+/-12% of the observed spin-echo fMRI signal at 9.4T. These data suggest that correcting BOLD effect may be necessary for accurately quantifying activation-induced CBV changes at high field.