Search

Environmental (e)DNA methods have enabled rapid, sensitive and specific inferences of taxa presence throughout diverse fields of ecological study. However, use of eDNA results for decision-making has been impeded by uncertainties associated with false positive tests putatively caused by sporadic or systemic contamination. Sporadic contamination is a process that is inconsistent across samples and systemic contamination occurs consistently over a group of samples. Here, we used empirical data and laboratory experiments to (i) estimate the sporadic contamination rate for each stage of a common, targeted eDNA workflow employing best practice quality control measures under simulated conditions of rare and common target DNA presence, (ii) determine the rate at which negative controls (i.e., "blanks") detect varying concentrations of systemic contamination, and (iii) estimate the effort that would be required to consistently detect sporadic and systemic contamination. Sporadic contamination rates were very low across all eDNA workflow steps, and, therefore, an intractably high number of negative controls (>100) would be required to determine occurrence of sporadic contamination with any certainty. Contrarily, detection of intentionally introduced systemic contamination was more consistent; therefore, very few negative controls (

While aggregate recycling rates in developed countries have plateaued in recent years, the contamination rate of recycling streams due to consumers incorrectly recycling items that cannot be recycled has grown rapidly. We propose that this problem may be partially due to persuasive messages, such as pro-environmental labeling on bins, that encourage recycling, but may lack guidance on how to do so accurately. For example, a number of public garbage receptacles across the U.S. are labeled “Landfill” instead of “Trash,” encouraging recycling by making the negative impact of garbage more salient. However, this labeling may also lead consumers to incorrectly “recycle” items that cannot be recycled (i.e., overinclusive recycling). Two field studies suggest that pro-environmental receptacle labeling can lead to overinclusive recycling, and a controlled experiment provides preliminary process evidence involving anticipated emotion from trashing versus recycling. Research opportunities and public policy implications for point-of-disposal labeling are discussed.

Purpose To assess the influence of donor, environment and storage factors on the contamination rate of organ-cultured corneas, to consider the microbiological species causing corneal contamination and to investigate the corresponding sensitivities. Methods Data from 1340 consecutive donor corneas were analysed retrospectively. Logistic regression analysis was used to assess the influence of different factors on the contamination rate of organ-cultured corneas for transplantation. Results The mean annual contamination rate was 1.8 ± 0.4% (range: 1.3–2.1%); 50% contaminations were of fungal origin with exclusively Candida species, and 50% contaminations were of bacterial origin with Staphylococcus species being predominant. The cause of donor death including infection and multiple organ dysfunction syndrome increased the risk of bacterial or fungal contamination during organ culture (p = 0.007 and p = 0.014, respectively). Differentiating between septic and aseptic donors showed an increased risk of contamination for septic donors (p = 0.0020). Mean monthly temperature including warmer months increased the risk of contamination significantly (p = 0.0031). Sex, donor age, death to enucleation, death to corneoscleral disc excision and storage time did not increase the risk of contamination significantly. Conclusion The genesis of microbial contamination in organ-cultured donor corneas seems to be multifactorial. The main source of fungal or bacterial contamination could be resident species from the skin flora. The rate of microbial contamination in organ-cultured donor corneas seems to be dependent on the cause of donor death and mean monthly temperature.

Objectives The clean-catch method of urine collection carries a high contamination rate. This study aims to evaluate the effects on contamination rate of providing a parent handout and pre-made urine collection pack for clean-catch urine collection. Methods We conducted a single-centre prospective cohort interventional study in a tertiary paediatric ED. All children younger than 24 months who presented from April 2013 to June 2014 requiring a urine sample to be obtained were included. The intervention was provision of a pre-made urine collection pack including a standardised information handout. The primary outcome measure was the difference in proportion of urine contamination in samples obtained via a clean-catch pre- and post-intervention. Results The total number of urine specimens included was 288 in the pre-intervention group and 333 in the post-intervention group. Contamination rates were 14.9% in the pre-intervention group and 11.4% in the post-intervention group. There was no statistically significant reduction in contamination (P = 0.19). The contamination rates appeared to be associated with gender, with (pooled) female contamination rates being 16.4% (44/269) and male contamination rates being 10.5% (37/352). Most specimens of urine were collected via the clean-catch method (81.2%), followed by catheter urine specimen (13.7%) and suprapubic aspirate (5.1%). The contamination rate in our study for clean-catch urine collectively was 13%, catheter urine specimen 3.8% and suprapubic aspirate 0%. Conclusion The contamination rate of clean-catch urine did not improve with the implementation of a pre-made urine collection pack including standardised written instructions.

Multicenter studies are widely used to meet accrual targets in clinical trials. Clinical data monitoring is required to ensure the quality and validity of the data gathered across centers. One approach to this end is central statistical monitoring, which aims at detecting atypical patterns in the data by means of statistical methods. In this context, we consider the simple case of a continuous variable, and we propose a detection procedure based on a linear mixed-effects model to detect location differences between each center and all other centers. We describe the performance of the procedure as a function of contamination rate and signal-to-noise ratio. We investigate the effect of center size and variance structure and illustrate the use of the procedure using data from two multicenter clinical trials. Copyright © 2014 John Wiley & Sons, Ltd.

Objective To determine the methicillin-resistant Staphylococcus aureus (MRSA) and methicillin-resistant Staphylococcus pseudintermedius (MRSP) contamination rate of white coats (WC) and surgical scrubs (SS) worn by personnel at the Ontario Veterinary College Health Sciences Centre (OVCHSC) and to identify risk factors associated with clothing contamination. Study Design Cross-sectional study. Sample Population Personnel including clinical faculty, house officers, technicians, and veterinary students working at the OVCHSC. Methods Electrostatic cloths were used to sample WC and SS of hospital personnel. Samples were tested for MRSA and MRSP and isolates were typed. Participants completed a self-administered questionnaire and data was evaluated for risk factors. Results Of 114 specimens, MRS were isolated from 20 (17.5%), MRSA from 4 (3.5%), and MRSP from 16 (14.0%). Technicians were 9.5× (OR = 0.95, 95% CI: 1.2–∞, P = .03) more likely than students to have clothing contaminated with MRSA. No risk factors were identified for MRSP or for overall MRS contamination. Conclusions Standard hospital clothing was found to have a high prevalence of MRS contamination in a veterinary teaching hospital and could be a source of hospital-acquired infections.

SUMMARYBackground Significant efforts have been made towards bacterial risk minimization by limiting the chance of bacteria entering into collected blood, detecting its presence and eliminating them by pathogen reduction technology. Improved skin disinfection and the use of diversion pouch are effective upstream measures to reduce the risk of bacterial sepsis. Here we report on our experience with the use of blood bags with diversion pouch. Materials and methods An observational study was performed to compare the bacterial contamination rate for two periods of time, i.e. before and after introduction of diversion pouch into blood bags. The incidence of bacterial contamination was monitored by the existing bacterial surveillance programme using pooled samples from 5 units of random donor platelets underwent aerobic culture in the BacT/ALERT 3D system. Results Between 1 June 2004 and 31 May 2006 (blood bag without diversion pouch), 50 (0·0213%) out of 234 252 units of random donor platelets were found to have bacteria on culture whereas 15 (0·0057%) isolates out of 262 156 units were found from 1 June 2007 to 31 May 2009 (after diversion pouch was introduced). Overall, there was an 85% reduction in bacterial contaminated risk due to skin flora (P

Demographische und historische Analyse der Hamburger Hornhautbank uber 30 Jahre Purpose: To evaluate donor demographics, trends in donor tissue procurement and tissue storage over a long period. Methods: A retrospective, longitudinal, descriptive analysis was undertaken of data from the Hamburg Eye Bank Data Base (HEB-DB) that had been collected between 1981 and 2010. Data on 54 parameters of cornea donors [including clinical history, age, death cause, gender and death-to-explantation interval (DEI)]and of cultivated corneas (endothelial quality and development in culture, cultivation period, microbiological contamination) were retrieved. These data were analysed statistically, focusing on the historical development of the eye bank. Results: At the time of retrieval (June 2010), the HEB-DB contained data on 10 943 corneas (5503 donors). Most donors were men (65%) and had died from cardiopulmonary (n = 801) ⁄ cerebral (n = 261) failure or as the result of a polytraumatic accident ⁄ suicide (n = 602). Within these years, donor age,DEI and storage time increased. The percentage of stored corneas suitable forntransplantation displayed a variable but increasing trend; in 2007, almost 75% of the stored corneas were transplanted. Between 1995 and June 2010, the median microbiological contamination rate was 5.3%. A change in the procurement procedure from enucleation to corneoscleral explantation in 2008 led to a briefly increased contamination rate. Conclusion: Donor demographic data run parallel to the general demographic development. Our analysis indicates a dynamic development of the eye bank over the last 30 years and emphasizes the need for an active quality management in coping with the challenges of modern eye banking.

BACKGROUND: The Pan Genera detection (PGD) test is used to screen platelet (PLT) products for bacterial contamination. We report the experience of using the PGD test on whole blood–derived PLTs (WBPs) at two large centralized transfusion services (CTS). STUDY DESIGN AND METHODS: Records of PGD test results were retrospectively reviewed. The PGD test was performed on individual WBP units or pools of WBPs ranging in size from 2 to 6 units at the time of issue. Bacterial culture was performed on PLT products with positive PGD tests, and at one CTS, the available cocomponents. RESULTS: A total of 70,561 WBP pools were screened with the PGD test. There were seven true-positive PGD tests and 242 false-positive tests (positive predictive value of PGD test, 2.81%). The overall contamination rate was 99 per 106 WBP pools (1:10,080; 95% confidence interval [CI], 40-204), and the false-positive rate was 3430 per 106 WBP pools (1:292; 95% CI, 3011-3890). All seven bacterial isolates were Gram positive. The median age of the individual WBP units in the seven contaminated pools was 5 days (range, 3-5 days) compared to 4 days (range, 1-5 days) in the false-positive pools (p = 0.0012). The same bacteria isolated from a positive PLT pool also grew in one red blood cell cocomponent. CONCLUSION: After testing more than 70,000 WBP pools at two large CTSs, the rate of contaminated WBP pools detected by the PGD test was 99 per 106 pools (1:10,080).

Background The use of nasal irrigation in the management of postoperative endoscopic sinus surgery (ESS) patients is commonplace; however, the potential contamination of these bottles is concerning. The Sinugator® cordless pulsating nasal wash (NeilMed Pharmaceuticals, Inc., Santa Rosa, CA) is a battery-operated, positive pressure, pulsatile pump with a unidirectional flow. The principal aim of this study was to determine the incidence of cross-contamination using the pulsating nasal irrigation device and compare it with the traditional squeeze bottle. Methods Eleven post-ESS patients were given a NeilMed Sinugator nasal wash to use 3 times per day. A sterile nasal swab was obtained at the initial and second postoperative visits. A swab of the plastic irrigation reservoir was collected at the second visit. Results The overall contamination rate of bottles was found to be 45%. During the study several different organisms were cultured in the nose and bottles. The most commonly isolated organisms were coliforms and Staphylococcus aureus. We did not observe concomitant organisms in the nasal cultures and bottles in any subject. Conclusion Despite using a motorized irrigation device, patients and their bottles grew positive cultures. However, no cross-contamination between the patients and bottles was identified, which can be attributed to a design that minimizes backwash.

Background and Objectives National guidelines for monitoring bacterial contamination of blood components were introduced in Germany in 1997. Between 1998 and 2002, numerous measures were implemented to prevent bacterial contamination. This study investigates their impact on contamination rates. Materials and Methods Culture-based testing for bacterial detection on a random sample of blood components is part of routine quality control in German blood establishments. Using standardized questionnaires, data from the production periods 1998, 2001 and 2005/2006 were collected and analysed. Results The bacterial contamination rate of RBCs was reduced from 0·157% in 1998 to 0·029% in 2005/2006 (P

Summary In the first half of 1962, 81.9% of the annual 185.000 tons of fish meal imported into The Netherlands originated from Peru and 9.2% from Chile. On the basis of a statistical study of this material, three bags of fish meal from each of 10 ships were collected in the latter half of 1962. From each of the 30 bags, 50 samples of 50 gr were examined each week until the contents of all bags had been completely examined. On the basis of the findings obtained in this way, it was calculated with 99% reliability that 26% of the bags of fish meal imported into The Netherlands (4 million bags per year) are contaminated with Salmonella. The contamination rate was calculated to be 31% with a reliability of 95%. In 8 out of 14 positive bags the serotypes found included S. typhi murium; this means that 10% (99% reliability) or 14% (95% reliability) of the bags of fish meal imported into The Netherlands are contaminated with S. typhi murium. A preliminary study of 7 bags of fish meal from Peru showed that no Salmonella could be isolated from five 10 gr samples obtained from five different sites in each bag. A subsequent examination of the entire bag contents (i. e. 1000 samples of 50 gr) showed that 6 of the 7 bags were contaminated by Salmonella. It is concluded that only a complete examination of a statistically correct random sample can give reliable information on the occurrence of Salmonella in imported lots of fish meal. We acknowledge with gratitude the cooperation of Dr. F. Drion, Director of the Data Processing Department, T. N. O., The Hague; the Executive of the Marketing Board for Animal Feeds, The Hague; the Executive of the Association of Animal Protein Importers, Rotterdam; and the General Inspection Service of the Ministry of Agriculture, The Hague. Without their cooperation, this study would have been impossible. Zusammenfassung Untersuchungen uber den Befall importierten Fischmehls mit Salmonellen In der ersten Halfte des Jahres 1962 kamen 81,9% der jahrlichen 185 000 Tonnen des in die Niederlande importierten Fischmehls aus Peru, wahrend 9,2% aus Chile stammten. Zwecks einer statistischen Studie dieses Imports wurden drei Packungen Fischmehl von jedem von 10 Schiffen in der zweiten Halfte des Jahres 1962 gepruft. Von jeder der 30 Packungen wurden jede Woche 50 Proben zu 50 g untersucht, bis der Inhalt aller Packungen vollstandig gepruft worden war. Auf Grund der auf diese Weise erhobenen Befunde wurde mit 99%iger Wahrscheinlichkeit berechnet, das 26% der Fischmehlpackungen, die nach den Niederlanden importiert wurden (4 Mill. Packungen pro Jahr), mit Salmonellen verunreinigt waren. Die Kontaminationsrate wurde bei einer Wahrscheinlichkeit von 95% mit 31% angegeben. In 8 von 14 positiven Packungen wurde durch die serologische Typendifferenzierung S. typhi murium ermittelt. Das bedeutet, das 10% (99% Wahrscheinlichkeit) oder 14% (95% Wahrscheinlichkeit) der nach den Niederlanden importierten Fischmehlpackungen mit S. typhi murium verunreinigt waren. Eine orientierende Untersuchung von 7 Fischmehlpackungen aus Peru zeigte, das Salmonellen aus funf 10 g Proben, die man an funf verschiedenen Stellen jeder Packung entnommen hatte, nicht isoliert werden konnten. Eine folgende Prufung des gesamten Packungsinhaltes (d.h. 1000 Proben zu 50 g) zeigte, das 6 von 7 Packungen mit Salmonellen verunreinigt waren. Daraus wird geschlossen, das nur eine vollstandige Untersuchung einer statistisch korrekten Anzahl von Stichproben eine zuverlassige Information uber das Auftreten von Salmonellen in importierten Fischmehlen geben kann. Resume Recherches sur le teneur des farines de poisson importees en salmonellas Dans la premiere moitie de l'annee 1962, 81,9% des 185.000 tonnes de farines de poisson importees annuellement aux Pays-Bas venaient du Perou tandis que 9,2% venaient du Chili. Aux fins d'etudes statistiques, on prelevait 3 sacs de farines de poisson sur 10 bateaux de chacune de ces provenance arrivant a quai pendant le second semestre de cette meme annee. Les 30 sacs de chaque origine furent examines a raison de 50 prelevements de 50 gr. par semaine jusqu'a epuisement du materiel d'examen. Les resultats obtenus prouvent, avec un taux de probabilite de 99%, que 26% des envois a destination des Pays-Bas (4 millions de sacs per an) sont infectes de salmonelles. Le taux d'infection peut etre evalue a 31% (taux de probabilite de 95%). Sur 14 sacs positifs, 8 l'etaient par S. typhi murium (typisation serologique). Cela signifie donc que 10% (taux de probabilite de 99%), resp. 14% (taux de probabilite de 95%) des sacs de farines de poisson importes aux Pays-Bas sont infectes de S. typhi murium. L'examen de 7 sacs de farines de poisson venant du Perou, procedant par 5 prelevements de 10 gr. en 5 endroits differents de chacun des sacs, n'a pas permi de deceler la presence de salmonelles. L'examen subsequent de la totalite du contenu des sacs (soit 1000 prelevements de 50 gr. chacun) a par contre montre que 6 des 7 sacs etaient infectes de salmonelles. On peut conclure que seul l'examen complet d'un nombre statistiquement correct de prelevements fournit des indications dignes de foi sur la presence ou non de salmonelles dans les farines de poisson importees. Resumen Estudios sobre la presencia de salmonelas en harinas de pescado importadas En los seis primeros meses del ano 1962, el 81,9% de las 185.000 toneladas de harinas de pescado importadas por los Paises Bajos procedia del Peru, mientras que el 9,2% era de Chile. Con miras a un estudio estadistico se analizaron 3 empaques de cada uno de los 10 barcos que arribaron en la segunda mitad del mismo ano. De cada uno de los 30 embalajes se analizaron cada semana 50 muestras de 50 grs. hasta que se controlo en su totalidad el contenido de todos los empaques. Basandose en los hallazgos registrados de esta forma se calculo con la probabilidad de un 99% que el 26% de los empaques de harina de pescado importados por Holanda (4 milliones de embalajes por ano) estaba impurificado por salmonelas. La cuota de contaminacion se calculo en un 31% para la probabilidad de un 95%. En 8 de 14 embalajes positivos se determino S. typhi murium mediante la diferenciacion serologica de tipos. Esto significa que el 10% (99% de probabilidad) de los empaques o el 14% (95% de probabilidad) de los embalajes de harina de pescado importados por los Paises Bajos estaban infectados con S. typhi murium. Un analisis orientador de 7 embalajes de harina de pescado procedentes del Peru demostro que no se pudieron aislar salmonelas a partir de cinco muestras de 10grs. que se habian tomado en 5 puntos diferentes de cada embalaje. El subsiguiente control de todo el contenido del empaque (es decir, 1000 muestras de 50 grs.) evidencio que 6 de 7 embalajes estaban impurificados por salmonelas. De aqui se deduce que solo un examen detenido y completo de un numero estadisticamente correcto de muestras tomadas al azar puede llegar a proporcionar una informacion segura sobre la presencia de salmonelas en harinas de pescado importadas.

Zusammenfassung: Der prapartale vaginale Hefebefall bei Schwangeren zeigte in fruheren Jahren eine gleichbleibende Haufigkeit von ca. 30 Prozent. 1972 wurde in der Rheinischen Landesfrauenklinik eine Kontamination von 27,6 Prozent ermittelt. In den seither vergangenen zehn Jahren haben diagnostische Methoden in der gynakologischen Praxis erheblich Boden gewonnen, die Forderung nach einer antepartalen vaginalen Hefebeseitigung ist den Frauenarzten intensiv nahegebracht worden. Die jetzt vorgelegte Untersuchung erbrachte eine Senkung der allgemeinen vaginalen Hefekontamination auf 21,4 Prozent. Die unterschiedliche Betrachtung der Kollektive Deutsche/Auslanderinnen zeigt, das die Kontaminationsrate bei Auslanderinnen mit 28,8 Prozent unverandert ist. Die Ursache darf in einer mangelnden Therapiecompliance dieser Patientengruppe gesehen werden. Im Kollektiv der deutschen Frauen wurde die Kontaminationsrate auf 17,7 Prozent gesenkt. Dies entspricht einer relativen Senkung der Hefebefallsrate von 1972 um 35,9 Prozent. Eine weitere Senkung durfte durch Verbesserung der Untersuchungsqualitat ante partum und weiterer konsequenter Forderungen nach Sanierung der mutterlichen Geburtswege erreicht werden. Summary: In recent years, the antenatal vaginal yeast contamination has to be known to be about 30 per cent. In 1972, the contamination in the Rheinische Landesfrauenklinik Wuppertal was found to be 27.6 per cent. In the recent ten years, diagnostic methods of gynecologic practitioners have been improved considerably. The demand for an elimination of the antenatal vaginal yeasts was repeated intensively. This study shows a diminution of the common antenatal vaginal yeast contamination to 21.4 per cent. The selective view of the different collectives of German and foreign women, however, shows an unchanged contamination rate of the foreign women. The reason is seen in an restricted compliance for therapy of this group of patients. In the German collective, the contamination rate is reduced to 17.7 per cent, which is equivalent to a relative reduction of the vaginal yeast contamination of 1972 to 35.9 per cent. A further diminution should be possible by a better quality of the investigations ante partum and a further consequent demand for sanitation of the mother's birth-channel.

Foodborne illnesses are a substantial health burden in the United States, with Campylobacter, pathogenic Escherichia coli and Salmonella reported among the major bacterial foodborne pathogens. These organisms are often present in fresh meat and poultry with regional differences in incidence. The objectives of this study were (1) to determine occurrence of foodborne pathogens Campylobacter and Salmonella as well as generic Escherichia coli in raw meats sold in retail grocery stores in the Fargo metropolitan area of North Dakota in the Midwestern United States; and (2) to correlate observed prevalence with the product type and retail store. A total of 456 fresh raw meats (turkey, chicken, pork, beef) were purchased and tested for microbial contamination. Overall, 341 (75%) of the samples were contaminated with generic E. coli (n = 316, 72%), Campylobacter (n = 12, 2.6%) and Salmonella (n = 13, 2.9%). The meats differed significantly (P

Purpose: This study aimed to examine the rates of microbial contamination, and identify contaminants associated with contact lenses and lens care accessories used by a group of young contact lens wearers. Methods: Collected contact lenses, lens cases, and lens care solutions were studied by bacterial culture. Contamination rates of these samples were recorded and compared with those reported in previous studies. Results: Of the samples tested, 9% of lens extracts, 34% of case extracts and 11% of solution samples were contaminated with ocular pathogenic microorganisms. Serratia spp., Staphylococcus aureus and coagulase-negative staphylococci were the most common microorganisms isolated. Lens cases were the most frequently contaminated item. Lens cases also yielded the widest range of bacterial isolates. Contact lenses used by occasional wearers were associated with a higher contamination rate. Using either saline or multipurpose solution to rinse lenses before use appeared to be effective in reducing incidence of contamination. Conclusion: Our findings demonstrate that contact lenses and lens care accessories are not well maintained by contact lens wearers. Regular reviews and reinforcement of lens care procedures for the usage and care of contact lenses and lens care accessories is therefore important and essential.

BACKGROUND: To minimize the bacterial contamination rate in blood collected from donors, a study was designed to evaluate the suitability of a single-use chlorhexidine-alcohol antiseptic for donor arm preparation at all blood collection venues in Australia. STUDY DESIGN AND METHODS: A prospective study of bacterial load on the skin was performed on 616 blood donors’ arms before and after disinfection using a direct swabbing and plating technique. Disinfection was achieved with a swab containing 1 percent chlorhexidine gluconate with 75 percent alcohol, which was applied to the skin in a prescribed method. Feedback from blood donors and staff was obtained using questionnaires. RESULTS: After disinfection, 99 percent of donor arms had bacterial counts of 5 cfu per plate or less, and 99.5 percent had counts of 10 cfu per plate or less, respectively. The mean colony count for all donors after disinfection was 0.39, and the percentage reduction was 99 compared to predisinfection. Sixteen donors (3%) noted transient skin irritation. The majority of staff (64%) preferred not to use the new disinfectant due to the difficulty opening the packaging and an excessive amount of antiseptic solution per pack. CONCLUSION: The bacteriologic study showed that the disinfectant satisfied the requirements of the Australian Red Cross Blood Service for use to prepare blood-donor arms before venesection. An improvement to the packaging was required before it could be acceptable to all staff.

BACKGROUND: Patients undergoing high-dose radio- and/or chemotherapy and autologous or allogeneic PBPC transplantation are at high risk for infections owing to profound immunosuppression. In this study, the rate of microbial contamination of ex vivo processed PBPC products was analyzed, comparing preparation under clean room conditions to standard laboratory conditions. STUDY DESIGN AND METHODS: After implementation of good manufacturing practice conditions in the two participating institutions, the microbial contamination rate of 366 PBPC harvests from 198 patients was determined under certified clean room conditions (Group A) from 2000 until 2002. To investigate influence of improved environmental conditions along with other parameters, this set of samples was compared with a historical control set of 1413 PBPC products, which have been processed ex vivo under a clean bench in a regular laboratory room and were harvested from 626 patients (Group B) from 1989 until 2000. RESULTS: In Group B microbial contamination was found in 74 PBPC products (5.2%) from 57 patients. In Group A microbial growth was detected in 3 leukapheresis products (0.8%) from 3 patients. After exclusion of PBPC products, which were probably contaminated before manipulation, statistical analysis showed a significant difference (χ2= 10.339; p < 0.001). CONCLUSION: These data suggest an impact of clean room conditions on the bacterial contamination rate of PBPC products. To identify confounding variables, variables like technique of leukapheresis, culture methodology, and microbial colonization of central venous catheters were taken into account. Further variables might be identified in following studies.

Summary. To investigate whether packed red cells (PRCs) prepared from autologous cord blood-packed red cells (AC-PRCs) could be used as an alternative for homologous-packed red cells (H-PRCs), we developed a system to collect and prepare AC-PRCs and determined standard storage parameters during 35 days of storage in extended storage medium (Sag-mannitol). We collected and fractionated cord blood from 390 newborns. The amount and quality of the AC-PRCs were analysed. The bacterial contamination rate was 1·84%. Twelve AC-PRCs were stored for 35 days, and standard laboratory parameters were measured at day 1 and day 35. The initial laboratory parameters of the AC-PRCs were similar to the parameters of the H-PRCs. After 35 days, the AC-PRCs displayed an increased haemolysis rate compared to H-PRCs (1·1 versus 0·2%) and also a significant decreased adenosine triphosphate value (1·2 versus 2·3 µmol L−1). Haemoglobin, haematocrit and pH were comparable in both groups. AC-PRCs meet the quality criteria for H-PRCs after 35 days. Utilizing a closed collection system for cord blood and an extended storage medium will increase safety and quality and facilitate the routine transfusion of autologous red cells derived from cord blood.

Background: In the acute care setting, closed enteral feeding systems have been found to be cost effective when compared with traditional open systems. Because the majority of studies have been conducted in acute care, the following variables pertaining to the open and closed systems were studied in two long-term care facilities: nutritional intake, formula waste, bacterial contamination, diarrhea, nursing time, nursing satisfaction, and cost. Cost included formula, formula waste, and administration sets. Methods: An experimental, randomized crossover design with quantitative and qualitative data was used on a sample of 36 patients, mainly brain injured, who were receiving intermittent enteral feeding. The study was completed in 7 weeks. At the onset, patients were randomly selected to either the closed or open system. Crossover occurred in week 4. In weeks 2, 3, 5, and 6, data collection occurred. Time motion studies of 20 nurses were completed in week 6. Twenty-nine nurses completed the nursing satisfaction surveys in week 7. Results: No significant differences were found in the amount of formula infused and formula wasted. A significant difference (p = .001) in bacterial contamination was found, with a significant contamination rate of 78% in the open and 39% in the closed systems. No significant differences were noted in diarrhea. Time motion studies of 20 nurses revealed no significant differences. In the nursing satisfaction survey of a convenience sample of 29 nurses, nurses expressed more satisfaction with the open system than the closed. Cost analysis revealed that the closed system was more expensive at $7.85 (Canadian)/patient/d compared with the open at $4.78. Conclusions: Decisions relating to choice of enteral feeding systems for patients must include a thorough study of all pertinent variables. Significant differences between the two systems in relation to bacterial contamination and cost were found. The potential complications of bacterial contamination in open

Summary We prospectively audited the bacterial contamination of re-useable analgesia infusion pumps. In a one-month period, 112 samples from the handset and keypads of our analgesia infusion pumps were cultured for bacterial contamination. Forty-five percent of handset swabs and 46% of keypad swabs grew bacteria; the commonest organism being coagulase-negative staphylococcus. An additional cleaning step using 70% isopropyl alcohol wipes was introduced and the contamination rate was re-audited in 100 samples. The contamination rate was reduced to 6% of handset swabs and 4% of keypad swabs. A high initial rate of bacterial contamination of re-useable analgesia infusion pumps was significantly reduced by the implementation of a simple, additional cleaning procedure.

Summary A one year prospective study was conducted to determine the association between intravenous catheter contamination and increased dwell time, and to identify any related risk factors. Intravenous catheters obtained from 23 cats and 98 dogs in the Intensive Care Unit at the Ontario Veterinary College with dwell times > 72 hours for the test group (n=58) and < 72 hours for a corresponding control group (n=63) were cultured between April 1991 and March 1992. One hundred and twenty one catheters were cultured, 16 jugular, 99 cephalic, and 6 saphenous. The overall contamination rate was 13 out of 121 catheters cultured (10.7%); 9/63 (14.3%) control and 4/58 (6.9%) test catheters. The bacteria isolated were E.aerogenes, S.aureus (3), P.aeruginosa, P.multocida, and Bacillus sp (7). The Bacillus sp positive catheters (5 control and 2 test) were placed during a five day period, and contaminated gauze squares were identified as the source of infection in these catheters. After these were removed from the study, the group infection rate was 6.9% control and 3.6% test. There was no significant difference between groups and no associated risk factors were identified. We conclude that intravenous dwell time need not be restricted to

Summary In this prospective study we analysed 336 consecutive central venous catheters in neonates less than 3500 g. A protocol standardizing the technique of insertion, the care of the catheter, the preparation of solutions and weekly bacteriological screening was applied to all catheter insertions. Mechanical complications were observed in 15 (6%), catheter dislodgement (5%), obstruction (8%), perforation (2%) and caval vein thrombosis (0.6%). Routine bacteriological cultures of feeding solutions and infusion devices showed a contamination rate of 3.5% and 2%. Skin swab and catheter tip cultures after catheter removal demonstrated positive results in 6% and 4.7%, but catheter related sepsis occurred in only 2.3%. Staphylococcus epidermidis was found in 81% of all positive bacterial cultures. Four point seven per cent of catheters were removed for suspected infection though only one third of them produced a bacteriological growth. We conclude that the risk of mechanical complications and contamination of central venous catheters in neonates can be minimized by the use of a standardized protocol.

Background: Bacterial contamination of enteral feeding solutions has been associated with a variety of infectious complications. In order to minimize contamination of enteral feeding solutions, it is recommended that their infusion times be limited. This leads to wasted product and inefficient use of personnel time. The contamination rate for sterile, non-air-dependent, closed system enteral feeding solutions and the length of time over which they can be safely infused in immunocompromised patients is not known. Methods: Enteral feeding was administered to 15 liver transplant recipients via a sterile, closed, non-airdependent system. At the conclusion of infusion of each bag of enteral feeding solution, the residual solution was quantitatively cultured. Subjects were also monitored for infectious complications. Results: The mean infusion time per 1.5-L bag of enteral feeding solution was 22.7 hours (range 10 hours to 35 hours). None of the 52 samples harbored bacteria. No subject developed a nosocomial in...

Background: The objective of this study was to determine the contamination rate of the health care workers’ (HCWs) mobile phones and hands in operating room and intensive care unit (ICU). Micro-organisms from HCWs hands could be transferred to the surfaces of the mobile phones during their use. Methods: Two hundred HCWs were screened; samples from the hands of 200 participants and 200 mobile phones were cultured. Results: In total, 94·5% of phones demonstrated evidence of bacterial contamination with different types of bacteria. The Gram-negative strains isolated from mobile phones were 31·3%, and the ceftazidime-resistant strains from the hands were 39·5%. Staphylococcus aureus strains isolated from mobile phones of 52% and those strains isolated from hands of 37·7% were methicillin resistant. Distributions of the isolated micro-organisms from mobile phones were similar to those from hands isolates. Some mobile phones were contaminated with nosocomial important pathogens. Conclusion: These results showed that HCWs hands and their mobile phones were contaminated with various types of micro-organisms. Mobile phones used by HCWs in daily practice may be a source of nosocomial infections in hospitals. Abstract reprinted from Annals of Clinical Microbiology and Antimicrobials, volume 8, Ulger F et al., ‘Are we aware how contaminated our mobile phones with nosocomial pathogens?’, doi:10.1186/1476-0711-8-7. © 2009, reproduced with permission from BioMed Central Ltd.

Infrared (IR) analysis of headspace gas for the presence of CO2 was evaluated as a method of nondestructively sampling and segregating microbiologically contaminated products. Approximately 1.8 million 7-oz bottles containing citrus juices and fruit drinks were inspected and segregated based on IR CO2 analysis. Comparison of IR analysis with conventional plating methods indicated 89% of the samples determined to be positive by conventional methods were also detected by IR analysis. False negatives were found to be the result of nonfermentative microorganisms in over 80% of the contaminated samples not detected by IR analysis. Nonfermentative organisms were identified and effects on product were evaluated. The expected contamination rate was 5.3% compared to 6.3% contamination detected by IR analysis. SUMMARY IN SUMMARY, an IR CO2 analyzer was utilized successfully to inspect 100% of product suspected of microbial contamination. When proper procedures were followed, contaminated product was detected and removed for destruction while good product was recovered for subsequent shipment to consumers. This system is advantageous because it allows for a 100% nondestructive inspection, is comparable to conventional plating methods in determining the presence of microbial contamination, and can be automated to a high degree. It is probable that automated container handling would have resulted in fewer false positives due to tilting of bottles as well as elimination of false negatives containing CO2 which were the result of insufficient time of analysis. Disadvantages include the requirement of an IR detectable microbial product, a container or package adaptable to an IR transmission or reflection type analysis, and a considerable cost for equipment. Any product contaminated by fermentative microorganisms and packaged in glass containers having a headspace of approximately 0.5 inch could be inspected by the methods described here. Justification for the cost of equipment would depend on the amount of contaminated product and the expected recovery rate. It is quite possible that future application of IR analysis could include monitoring food process streams for indicators of microbial contamination.

Basing on a review of the present situation of the contamination of milk and powdered milk products with aflatoxin M1 a further investigation is regarded as necessary to assess the hygienic toxicological situation. For this purpose the TLC detection method of Tuinstra and Bronsgeest is recommended, which was modified to be used with powdered milk and baby food. This method enables the detection of 0.04 micrograms M1/l milk and 0.5 micrograms/kg powdered milk respectively on practical conditions. Investigating 142 raw milk samples and 70 samples of powdered milk products only 2 positive powdered milk samples were detected. This relatively low contamination rate is explained by the use of feed that is predominantly produced in the GDR and that is vastly free from aflatoxins. According to these results it is possible to estimate the contamination of milk with aflatoxin M1 in the GDR as extremely low.

After a brief description of the mechanism of the contamination layer build-up the following topics are discussed: atomic number dependence of the contamination rate, composition of contamination layers, X-ray intensity loss caused by a contamination layer, special problems in energy dispersive analysis, useful aspects of specimen contamination. Nach einer kurzen Beschreibung der Mechanismen, die bei der Bildung von Kontaminationsschichten wirksam sind, werden die Abhangigkeit der Kontaminationsrate von der Ordnungszahl der Probe, die Zusammensetzung von Kontaminationsschichten, der durch Kontamination verursachte Intensitatsverlust der probenspezifischen Rontgenstrahlung, spezielle Probleme dr energiedispersiven Rontgenmikroanalyse sowie nutzliche Aspekte der Kontamination behandelt.

Samples of reconstituted frozen red blood cells, maintained at 4 C for 72 hours prior to culture, revealed a bacterial contamination rate of less than 0.2 per cent, suggesting that the present shelf life of 24 hours may be safely extended to 72 hours.