Inadvertent Contamination Research Articles

Preventing inadvertent contamination of the sterile field during draping

Preventing inadvertent contamination of the sterile field during draping

Characterization of a cell bridge variant connecting the nodose and superior cervical ganglia in the mouse: Prevalence, anatomical features, and practical implications.

While autonomic ganglia have been extensively studied in rats instead of mice, there is renewed interest in the anatomy of the mouse autonomic nervous system. This study examined the prevalence and anatomical features of a cell bridge linking two autonomic ganglia of the neck, namely, the nodose ganglion (NG) and the superior cervical ganglion (SCG) in a cohort of C57BL/6J mice. We identified a cell bridge between the NG and the cranial pole of the SCG. This cell bridge was tubular shaped with an average length and width of 700 and 240 μm, respectively. The cell bridge was frequently unilateral and significantly more prevalent in the ganglionic masses from males (38%) than females (21%). On each of its extremities, it contained a mixed of vagal afferents and postganglionic sympathetic neurons. The two populations of neurons abruptly replaced each other in the middle of the cell bridge. We examined the mRNA expression for selected autonomic markers in samples of the NG with or without cell bridge. Our results indicated that the cell bridge was enriched in both markers of postganglionic sympathetic and vagal afferents neurons. Lastly, using FluoroGold microinjection into the NG, we found that the existence of a cell bridge may occasionally lead to the inadvertent contamination of the SCG. In summary, this study describes the anatomy of a cell bridge variant consisting of the fusion of the mouse NG and SCG. The practical implications of our observations are discussed with respect to studies of the mouse vagal afferents, an area of research of increasing popularity.

Food Allergen and Gluten Training and Awareness Among Restaurant Workers Serving Gluten-Free Foods

Abstract Objectives Adherence to a strict gluten free (GF) diet is critical for patients with gluten related disorders (GRDs). Even though meals that are labeled or advertised as being GF are widely available in restaurants, their safety remains questionable. To protect customers with GRDs, restaurant workers need to be trained in proper procedures regarding food allergens, food intolerances and sensitivities. The purpose of this study was to assess training and awareness about gluten and GRDs among employees in restaurants that offered GF menu options. Methods A 28 question survey was created and distributed to restaurant employees nationwide. Employees were surveyed on food allergen training and their knowledge about gluten. Data were collected from 583 respondents who met the inclusion criteria. Relationships between variables were determined by chi square analysis. Effect size of statistically significant associations was determined by Cramer's V. Results Respondents to the survey were restaurant owners (37.1%), general managers (23.9%), lower level managers (9.8%), executive chefs and sous chefs (11%), culinary workers (chefs, cooks, line cooks and others 10%) and servers (7.9%). A majority (93%) of participants, reported that their restaurant was able to accommodate guests who requested a GF meal. Most (75.4%) employees reported that food allergen training took place at their restaurant. However, only 57.4% of employees had completed the training, with servers and kitchen staff the least likely to receive training at their current work place. At least 24.3% of all restaurant employees had never had training in the knowledge and handling of food allergens and/or gluten. When employees were categorized by job title, 43.5% of chefs, cooks, and line cooks and only 26.3% servers had completed food allergen training at their current restaurant. Most workers had heard of GRDs but only 52.6% of respondents recognized that celiac disease was an autoimmune disease triggered by gluten. Restaurant employees who had received food allergen training were significantly (P = .007) more likely to be aware of GRDs than those who had not. Conclusions Educating restaurant workers catering to clients with GRDs must be mandatory in order to safeguard meals served from inadvertent contamination with gluten. Funding Sources Eastern Michigan University, School of Health Sciences.

Considerations for Pediatric Heart Programs During COVID-19: Recommendations From the Congenital Cardiac Anesthesia Society.

Considerations for Pediatric Heart Programs During COVID-19: Recommendations From the Congenital Cardiac Anesthesia Society.

Are we There Yet? Understanding Interplanetary Microbial Hitchhikers using Molecular Methods.

Since the early time of spacetravel, planetary bodies undergoing chemical or biological evolution have beenof particular interest for life detection missions. NASA's and ESA's PlanetaryProtection offices ensure responsible exploration of the solar system and aimat avoiding inadvertent contamination of celestial bodies with biomolecules oreven living organisms. Lifeforms that have the potential to colonize foreign planetarybodies could be a threat to the integrity of science objectives of lifedetection missions. While standard requirements forassessing the cleanlinessof spacecraft are still based on cultivation approaches, several molecularmethods have been applied in the past to elucidate the full breadth of(micro)organisms that can be found on spacecraft and in cleanrooms, where thehardware is assembled. Here, we review molecular assays that have been appliedin PlanetaryProtection research and list their significant advantages anddisadvantages. By providing a comprehensive summary of the latest molecularmethods yet to be applied in this researcharea, this article will not only aidin designing technological roadmaps for future Planetary Protection endeavorsbut also help other disciplines in environmental microbiology that deal withlow biomass samples.

Outbreak of Acinetobacter baumannii associated with extrinsic contamination of ultrasound gel in a tertiary centre burn unit

SummaryBackgroundDuring 2011 and 2012, an increase in occurrence of multidrug-resistant Acinetobacter baumannii infections was recorded in the Shands Hospital Burn Intensive Care Unit (BICU). An epidemic curve together with strain typing was consistent with an intermittent common source outbreak. An investigation was therefore initiated.AimTo identify risk factors for A. baumannii infection, characterize the source of the pathogen, implement control measures to terminate the outbreak, and institute preventive measures.MethodsWe conducted a retrospective case-control study; reviewed BICU infection control policies, practices and procedures, and patient exposure to healthcare workers (HCWs), and obtained epidemiologically-directed environmental cultures.FindingsEleven patients met the case definition. On multivariate analysis, case-patients were more likely to have undergone an ultrasound procedure in the BICU (adjusted odds ratio [AOR]: 19.5; confidence interval [CI]: 2.4–435) or have a FlexiSeal™ device (AOR: 11.9, CI:1.3–276). Epidemiologically-directed cultures of the environment, ultrasound equipment, and ultrasound gel from opened containers on the ultrasound trolley and in the Ultrasound Department were negative for the outbreak pathogen. Culture of an open ultrasound gel dispenser stored in the Ultrasound Department yielded an A. baumannii strain with DNA banding patterns identical to the outbreak strain.ConclusionsBased on data from our epidemiologic, microbiologic, and observational studies, we believe that inadvertent extrinsic contamination of the gel dispenser occurred in the Ultrasound Department. Contaminated gel was then dispensed into multiuse vials of gel stored on the mobile carts. The outbreak was stemmed by instituting changes in practices in the Ultrasound Department, including introduction of single-use ultrasound vials and storage of ultrasound gel.

Does the Method of Sterile Glove-Opening Influence Back Table Contamination? A Fluorescent Particle Study

BackgroundSurgical site infections (SSI) may result from inadvertent intraoperative contamination events. This study investigated the method of opening surgical gloves onto the operative field (OF) and potential contamination rates. MethodsTwenty surgical glove packets were coated with a commercially available fluorescent particle powder. Two methods of glove openings (10 surgical glove packets in each cohort) were investigated: direct drop (DD) onto the OF vs opening and direct hand-off (DH) to a sterile intermediary (SI). Ultraviolet black light was used to quantify fluorescent particles for dispensed glove packets and the OF in both cohorts. The gloves of the SI were inspected in the DH cohort. A previously used contamination scale for fluorescent particle model contamination was employed: 0: no detectable fluorescent particle specks, 1: 1-5 specks, 2: 5-10 specks, 3: 11-100 specks, 4: >100 specks. ResultsThe DD cohort had a median OF contamination of 4 (range, 3-4) vs 3 for the DH trials (range, 1-3; P = .001). Likewise, the median glove contamination was higher in the DD cohort, 3 (range, 2-4) vs 1 for DH (range, 0-3; P = .007). Minimal contamination was found on the hands of the SI. Total fluorescent contamination rates, including the gloves of SI in the DH cohort, revealed greater overall contamination in DD (median, 3.5; range, 2-4) vs DH cohort (median, 1; range, 0-3); (P < .001). ConclusionUsing a fluorescent particle model, there is a greater burden of potential contamination from dispensed glove packets and OF with DD vs DH. The DH method did not show significant fluorescent particle contamination on the SI gloves. These data support the use of the opening of gloves via DH over the DD method in total joint arthroplasty to decrease the risk of potential contamination.

Evaluation of 12-Week Shelf Life of Patient-Ready Endoscopes.

Current research suggests that for certain types of gastrointestinal endoscopes, longer shelf life (the interval of storage after which endoscopes should be reprocessed before their reuse) may not increase the likelihood of endoscope contamination. Scope contamination may, in fact, be related primarily to either inadequate disinfection processes or inadvertent contamination during storage, not to duration of storage. The purpose of this study evaluated the presence of bacteria and fungus following liquid chemical sterilization in colonoscopes and gastroscopes, after 12 weeks of shelf life during which time personal protective equipment was used during endoscope storage cabinet access. We stored four colonoscopes and two gastroscopes in a cabinet for 12 weeks after liquid chemical sterilization and the cabinet was only accessed during the 12-week period wearing personal protective equipment (gown and gloves). Scopes were tested for bacteria and fungus at the end of 12 weeks. No bacteria or fungus grew on any of the scopes. This study provides further support that contaminated endoscopes may be related to either inadequate disinfection or contamination during storage, not shelf life.

AIUM Practice Parameter for the Use of Ultrasound to Guide Vascular Access Procedures.

AIUM Practice Parameter for the Use of Ultrasound to Guide Vascular Access Procedures.

The influence of intestinal microbiome on wound healing and infection

Wound healing problems and surgical site infections are commonly attributed to improper intraoperative technique and perioperative infection control methods. However, overwhelming evidence is emerging to suggest that the intestinal microbiome plays a profound and previously underappreciated role in infectious outcomes of surgery. Surgical stress and perioperative medical interventions alter the community structure and function of the intestinal microbiome. The resultant intestinal dysbiosis exerts overarching effects on the host immune and neuroendocrine systems. Although certainly infection is known to occur from inadvertent intraoperative contamination, a more intriguing concept is the possibility that alterations in the intestinal microbiome, occurring in response to the physiologic stress of surgery, may have a major negative influence on the host’s ability for tissue repair, regeneration, and resilience to infection.

Short communication: Pseudomonas azotoformans causes gray discoloration in HTST fluid milk

Pseudomonas species are well recognized as dairy product spoilage organisms, particularly due to their ability to grow at refrigeration temperatures. Although Pseudomonas-related spoilage usually manifests itself in flavor, odor, and texture defects, which are typically due to production of bacterial enzymes, Pseudomonas is also reported to cause color defects. Because of consumer complaints, a commercial dairy company shipped 4 samples of high temperature, short time (HTST)-pasteurized milk with distinctly gray colors to our laboratory. Bacterial isolates from all 4 samples were identified as Pseudomonas azotoformans. All isolates shared the same partial 16S rDNA sequence and showed black pigmentation on Dichloran Rose Bengal Chloramphenicol agar. Inoculation of one pigment-producing P. azotoformans isolate into HTST-pasteurized fluid milk led to development of gray milk after 14 d of storage at 6°C, but only in containers that had half of the total volume filled with milk (∼500 mL of milk in ∼1,000-mL bottles). We conclusively demonstrate that Pseudomonas can cause a color defect in fluid milk that manifests in gray discoloration, adding to the palette of color defects known to be caused by Pseudomonas. This information is of considerable interest to the dairy industry, because dairy processors and others may not typically associate black or gray colors in fluid milk with the presence of microbial contaminants but rather with product tampering (e.g., addition of ink) or other inadvertent chemical contamination.

Reinvestigation of the biological activity of d-allo-ShK protein

ShK toxin from the sea anemone Stichodactyla helianthus is a 35-residue protein that binds to the Kv1.3 ion channel with high affinity. Recently we determined the X-ray structure of ShK toxin by racemic crystallography, in the course of which we discovered that d-ShK has a near-background IC50 value ∼50,000 times lower than that of the l-ShK toxin. This lack of activity was at odds with previously reported results for an ShK diastereomer designated d-allo-ShK, for which significant biological activity had been observed in a similar receptor-blocking assay. As reported, d-allo-ShK was made up of d-amino acids, but with retention of the natural stereochemistry of the chiral side chains of the Ile and Thr residues, i.e. containing d-allo-Ile and d-allo-Thr along with d-amino acids and glycine. To understand its apparent biological activity, we set out to chemically synthesize d-allo-ShK and determine its X-ray structure by racemic crystallography. Using validated allo-Thr and allo-Ile, both l-allo-ShK and d-allo-ShK polypeptide chains were prepared by total chemical synthesis. Neither the l-allo-ShK nor the d-allo-ShK polypeptides folded, whereas both l-ShK and d-ShK folded smoothly under the same conditions. Re-examination of NMR spectra of the previously reported d-allo-ShK protein revealed that diagnostic Thr and Ile signals were the same as for authentic d-ShK. On the basis of these results, we conclude that the previously reported d-allo-ShK was in fact d-ShK, the true enantiomer of natural l-ShK toxin, and that the apparent biological activity may have arisen from inadvertent contamination with trace amounts of l-ShK toxin.

The mouse mammary gland as a sentinel organ: distinguishing \u2018control\u2019 populations with diverse environmental histories

BackgroundThere are numerous examples of laboratory animals that were inadvertently exposed to endocrine disrupting chemicals (EDCs) during the process of conducting experiments. Controlling contaminations in the laboratory is challenging, especially when their source is unknown. Unfortunately, EDC contaminations can interfere with the interpretation of data during toxicological evaluations. We propose that the male CD-1 mouse mammary gland is a sensitive bioassay to evaluate the inadvertent contamination of animal colonies.MethodsWe evaluated mammary glands collected from two CD-1 mouse populations with distinct environmental histories. Population 1 was born and raised in a commercial laboratory with unknown EDC exposures; Population 2 was the second generation raised in an animal facility with limited exposures to xenoestrogens from caging, feed, etc. Mammary glands were collected from all animals and evaluated using morphometric techniques to quantify morphological characteristics of the mammary gland.ResultsPopulation 1 (with suspected history of environmental chemical exposure) and Population 2 (with known limited history of xenoestrogen exposure) were morphologically distinguishable in adult males, prepubertal females, and pubertal females. Mammary glands from males raised in the commercial animal facility were significantly more developed, with larger ductal trees and more branching points. The appearance of these mammary glands was consistent with prior reports of male mice exposed to low doses of bisphenol A (BPA) during early development. In females, the two populations were morphologically distinct at both prepuberty and puberty, with the most striking differences observed in the number, size, and density of terminal end buds, e.g. highly proliferative structures found in the developing mammary gland.ConclusionsCollectively, these results suggest that the mouse mammary gland has the potential to be used as a sentinel organ to evaluate and distinguish animal colonies raised in different environmental conditions including potential EDC exposures. Our findings could help researchers that wish to perform a posteriori evaluations to determine whether inadvertent contamination with xenoestrogens (and potentially other EDCs) has occurred in their animal colonies, especially after new materials (feed, caging, water bottles) have been introduced. Finally, our results challenge the relatively common practice of using historical controls in toxicological experiments.

Fracture of a saddle fusion (weld) joint in high density polyethylene (HDPE) pipe

Abstract This article documents the materials evaluation of a fractured saddle fusion weld joint on high density polyethylene (HDPE) pipe. The fusion joint failed due to inadequate surface preparation or inadvertent contamination of pipe surfaces prior to fusion that led to a joint with incomplete fusion. Failure of a defective fusion joint at the service tee allowed natural gas to leak from the gas main and, in turn, the gas migrated into a building where it ignited. Optical, stereo microscope, and scanning electron microscope (SEM) were used to evaluate the fracture faces. Exemplar fusion joints were manufactured and subjected to drop weight testing. The fracture features from fusion joints subjected to drop weight testing provided invaluable guidance for determining the origin of the fracture and direction of fracture propagation. Fracture features from the fusion joint in HDPE pipe are displayed that are not readily available from open source reports.

A multiplex real-time PCR method for the quantitative determination of equine (horse) fractions in meat products

The recent horse meat scandal that rocked Europe in early 2013 shows how important it is for the routine food control authorities to constantly evolve analytical tools for the accurate evaluation of meat products among others, to ensure that product declaration and actual composition correlate. While in most cases qualitative detection approaches suffice for product evaluation, in other cases a quantitative analysis is important to distinguish between inadvertent contamination and deliberate adulteration.In this work an optimized real-time qPCR-based approach is presented and compared with another real-time based method for the detection of equine sequences among others in meat products. The method is a multiplex system for the simultaneous quantification of horse, beef, pork and sheep fractions, and was validated for use in the routine analysis of meat products. We describe a modular multiplex approach, where a quadruplex system (without sheep) and a pentaplex assay (with an integrated sheep detection system) can be applied in meat detection and quantification strategies. The analysis is matrix independent and relies on concomitant quantification of the animal species present in the food sample against the backdrop of myostatin, a universal sequence present in most mammalian and poultry species. The limit of detection of the analytical method was 10 genome copy equivalents. For validation of the method, meat samples comprising differing meat compositions were analysed, and the assay performed well in terms of robustness and reproducibility.

Potential harmful effects of dietary supplements in sports medicine.

The purpose of this article is to collect the most recent data regarding the safety of well-known or emerging dietary supplements used by athletes. From January 2014 to April 2016, about 30 articles have been published in the field. New data show that 90% of sports supplements contain trace of estrogenic endocrine disruptors, with 25% of them having a higher estrogenic activity than acceptable. About 50% of the supplements are contaminated by melamine, a source of nonprotein nitrogen. Additional data accumulate toward the safety of nitrate ingestion. In the last 2 years, the safety of emerging supplements such as higenamine, potentially interesting to lose weight, creatine nitrate and guanidinoacetic acid has been evaluated but still needs further investigation. The consumption of over-the-counter supplements is very popular in athletes. Although most supplements may be considered as safe when taking at the recommended doses, athletes should be aware of the potential risks linked to the consumption of supplements. In addition to the risks linked to overdosage and cross-effects when combining different supplements at the same time, inadvertent or deliberate contamination with stimulants, estrogenic compounds, diuretics or anabolic agents may occur.

Pitfalls of improperly procured adjacent non-neoplastic tissue for somatic mutation analysis using next-generation sequencing.

BackgroundThe rapid adoption of next-generation sequencing provides an efficient system for detecting somatic alterations in neoplasms. The detection of such alterations requires a matched non-neoplastic sample for adequate filtering of non-somatic events such as germline polymorphisms. Non-neoplastic tissue adjacent to the excised neoplasm is often used for this purpose as it is simultaneously collected and generally contains the same tissue type as the neoplasm. Following NGS analysis, we and others have frequently observed low-level somatic mutations in these non-neoplastic tissues, which may impose additional challenges to somatic mutation detection as it complicates germline variant filtering.MethodsWe hypothesized that the low-level somatic mutation observed in non-neoplastic tissues may be entirely or partially caused by inadvertent contamination by neoplastic cells during the surgical pathology gross assessment or tissue procurement process. To test this hypothesis, we applied a systematic protocol designed to collect multiple grossly non-neoplastic tissues using different methods surrounding each single neoplasm. The procedure was applied in two breast cancer lumpectomy specimens. In each case, all samples were first sequenced by whole-exome sequencing to identify somatic mutations in the neoplasm and determine their presence in the adjacent non-neoplastic tissues. We then generated ultra-deep coverage using targeted sequencing to assess the levels of contamination in non-neoplastic tissue samples collected under different conditions.ResultsContamination levels in non-neoplastic tissues ranged up to 3.5 and 20.9 % respectively in the two cases tested, with consistent pattern correlated with the manner of grossing and procurement. By carefully controlling the conditions of various steps during this process, we were able to eliminate any detectable contamination in both patients.ConclusionThe results demonstrated that the process of tissue procurement contributes to the level of contamination in non-neoplastic tissue, and contamination can be reduced to below detectable levels by using a carefully designed collection method. A standard protocol dedicated for acquiring adjacent non-neoplastic tissue that minimizes neoplasm contamination should be implemented for all somatic mutation detection studies.Electronic supplementary materialThe online version of this article (doi:10.1186/s12920-016-0226-1) contains supplementary material, which is available to authorized users.

The Saccharomyces cerevisiae response to stress caused by the herbicidal active substance alachlor requires the iron regulon transcription factor Aft1p.

In the Saccharomyces cerevisiae eukaryotic model, the induction of the iron regulon genes ARN1, FIT2 and CTH2 by growth-inhibitory concentrations of alachlor (ALA) was dependent on Aft1p expression. This transcription factor was found to be activated through its nuclear localization. The hypersensitivity of the aft1Δ mutant to ALA was abrogated by surplus exogenous iron, suggesting that the role of Aft1p in ALA tolerance may be associated with iron limitation under ALA stress. A transient decrease in the cellular iron content in the ALA-stressed cells supported this idea. In contrast to the upregulation of the nonreductive iron uptake genes ARN1 and FIT2 by ALA, thequantity of FET3 and FTR1 transcripts encoding the high-affinity iron uptake reductive pathway decreased. Yeast cells were apparently more sensitive to ALA when iron uptake occurred through the reductive pathway than when the nonreductive uptake of ferrichrome-bound ferric iron was dominant. On the other hand, the ALA hypersensitivity of the aft1Δ mutant was reversed by medium supplementation with glutathione or N-acetyl-L-cysteine. The results are compatible with possible links between ALA toxicity and perturbations in metal and antioxidant homeostasis, which may be relevant for environmental microbes and higher eukaryotes in situations of inadvertent herbicide contamination.

Quantification Analysis of the Intraoperative Bacterial Contamination Rate and Level in Osteochondral Autografts

Background: Inadvertent contamination of osteochondral (OC) autografts during harvesting and preparation can lead to significant complications and can cause the operating team to weigh the infection risk after reimplantation against discarding the OC fragment. The most commonly reported contamination mechanism is the accidental dropping of an OC fragment; however, associated contamination levels remain unclear. The rate and level of contamination during standard harvesting and preparation are also unknown. Purpose: To quantitatively evaluate the rate and level of bacterial contamination of OC autografts during harvesting and preparation compared with those of accidently dropped autografts. Study Design: Controlled laboratory study. Methods: Under sterile conditions, 138 fresh OC specimens were harvested and retrieved from 23 primary total knee arthroplasties (TKAs). Six OC fragments were retrieved from each TKA: 3 were used as controls, and 3 were dropped onto the operating room floor. Each specimen was incubated to allow for aerobic and anaerobic growth, and the number of colony-forming units (CFUs) per gram was calculated. Results: Contamination rates (positive cultures) for the control and dropped groups were 29% (n = 20/69) and 42% (n = 29/69), respectively. The difference in the contamination rate between groups was not statistically significant (P = .109). The most common organisms identified were Staphylococcus aureus (40%) in the control group and Staphylococcus epidermidis (24.1%) and Bacillus species (20.7%) in the dropped group. The contamination level (CFUs/g) for both groups was low. The median (range) CFUs/g among the contaminated specimens in the dropped and control groups were 27 (1-120) and 3 (1-15), respectively (P < .0001). Conclusion: A relatively high rate of OC autograft contamination can be expected during harvesting and preparation (29%) or after accidentally dropping a specimen (42%). Although the types of organisms isolated differed between specimens contaminated during harvesting and preparation and dropped specimens, the quantification of the autograft contamination level revealed a very low CFUs/g in both cases. Clinical Relevance: The intraoperative autograft contamination level is very low. Hence, in cases of grafts with a known contamination incident, saving and reimplanting them after proper decontamination is recommended over discarding them or using an allograft.

Clinical Effects of Gamma-Radiation-Resistant Aspergillus sydowii on Germ-Free Mice Immunologically Prone to Inflammatory Bowel Disease.

We report and investigated a case of inadvertent contamination of 125 mice (housed in two germ-free positive-pressurized isolators) with emerging human and coral pathogen Aspergillus sydowii. The infected mice correspond to genetic line SAMP1/YitFc, which have 100% immune predisposition to develop Crohn's disease-like spontaneous pathologies, namely, inflammatory bowel disease (IBD). Pathogen update based on a scoping review of the literature and our clinical observations and experimentation are discussed. The unwanted infection of germ-free mice (immunologically prone to suffer chronic inflammation) with human pathogen A. sydowii resulted in no overt signs of clinical disease over 3-week exposure period, or during DSS-induced colitis experiments. Results and observations suggest that A. sydowii alone has limited clinical effect in immunocompromised germ-free mice or that other commensal microbial flora is required for Aspergillus-associated disease to occur.