Pumping infusions with a syringe may cause contamination of the fluid in the syringe.

Clinicians often perform pumping of infusions with a syringe (PIS) to quickly deliver fluid or blood transfusion to patients, especially during an emergency. Despite the efforts of the clinicians, critically ill patients are prone to acquire catheter-related bloodstream infections. Although clinicians have reported the possibility of PIS contamination, no group of researchers has studied nor confirmed this possibility. Here, we examined whether PIS can cause bacterial contamination of the fluid inside the syringes, using microbiological tests, including the analysis Escherichia coli DH-5 alpha growth by measuring the absorbance at OD600. We confirmed that contamination of fluid in the barrel was almost proportional to the applied volume of bacterial fluid. Aliquots of DH-5 alpha artificially applied on the surface of the gloved hand of an examiner, the plunger or the inner side of the barrel of a syringe could permeate inside the syringe. Furthermore, disinfection with ethanol before PIS almost successfully prevented bacterial multiplication. Our findings suggest that PIS can cause intraluminal contamination when performed with unsterilized hands, and that previous disinfection with ethanol can effectively prevent PIS-induced contamination. These results highlight the risk of PIS-induced contamination and the importance of disinfection in the daily clinical practice.

Prolonged inhibitory effects against planktonic growth, adherence, and biofilm formation of pathogens causing ventilator-associated pneumonia using a novel polyamide/silver nanoparticle composite-coated endotracheal tube.

Microbial cells can rapidly form biofilm on endotracheal tubes (ETT) causing ventilator-associated pneumonia, a serious complication in patients receiving mechanical ventilation. A novel polyamide with a good balance of hydrophilic/hydrophobic moieties was used for the embedment of green-reduction silver nanoparticles (AgNPs) for the composite-coated ETT. The films were conformal with a thickness of ∼ 17 ± 3 µm accommodating high loading of 60 ± 35 nm spherical-shaped AgNPs. The coated ETT resulted in a significant difference in reducing both planktonic growth and microbial adhesion of single and mixed-species cultures, compared with uncoated ETT (p < 0.05). A time-kill assay demonstrated rapid bactericidal effects of the coating on bacterial growth and cell adhesion to ETT surface. Biofilm formation by Pseudomonas aeruginosa and Staphylococcus aureus, commonly encountered pathogens, was inhibited by > 96% after incubation for 72 h. Polyamide/AgNP composite-coated ETT provided a broad-spectrum activity against both Gram-positive and Gram-negative bacteria as well as Candida albicans and prolonged antimicrobial activity.

Validity of a disposable catheter to drain urine overnight in neurogenic bladder.

BACKGROUND: Overnight catheter drainage (OCD) is introduced to avoid overdistention of the bladder at night-time when clean intermittent catheterization proves ineffective for daytime management of neurogenic bladder. We adopted OCD using disposable silicone no-balloon (DSnB) catheters, with the distal end outside the body opening into diapers. OCD using DSnB catheter, however, had risks of retrograde bacterial contamination. Therefore, in this study, the validity of equipping DSnB catheters with check valves to prevent retrograde bacterial contamination was examined. METHODS: For the in vitro study, excised saline-filled swine bladders were drained using DSnB catheters with or without check valves, and the time required for intravesical pressure to reach 5 cmH2 O was measured. For the in vivo study, in cross-over experiments comparing DSnB catheters with and without check valves, OCD using DSnB catheters for 10 h was performed in rabbits under analgesia. Bacterial growth from urine samples before and after OCD and residual urine volume were examined. RESULTS: For the in vitro experiment, the median drainage time was 368.2 s (range, 88-1,085 s) and 344.7 s (range, 28-840 s) with and without check valves, respectively (n = 6), which was not significantly different. For the in vivo experiment, in cross-over experiments (n = 8) new bacterial growth rates after OCD did not differ, and median residual urine volume was 17.1 mL (range, 0-75 mL) and 1.2 mL (range, 0-5 mL) with and without check valves, respectively (P = 0.055). CONCLUSIONS: Installing a check valve in the DSnB catheter did not decrease new bacterial growth, while tending to increase residual urine volume. DSnB catheters without check valves appear to be better for continuous drainage of urine from bladder.

Contaminación microbiológica en humidificadores de sistemas de oxigenoterapia de alto y bajo flujo: una revisión sistemática / Microbiological contamination in high and low flow oxygen humidifiers: A systematic review

Objetivo: Determinar el riesgo de contaminación microbiológica de los humidificadores de burbujeo para oxigenoterapia de alto o bajo flujo de uso hospitalario. Métodos: Revisión sistemática de la literatura a través de 6 bases de datos bibliográficas. Se seleccionaron estudios observacionales o experimentales publicados entre 1990 y 2016, en inglés o español, que analizaban la contaminación microbiana de los humidificadores de burbujeo de los dispositivos de oxigenoterapia hospitalaria de alto y bajo flujo. Resultados: Se incluyeron 12 artículos: 4 analizaron el agua de humidificadores reutilizables, 4 de desechables y otros 4 compararon muestras procedentes de ambos modelos. Se observó la presencia de contaminación microbiana en todos los estudios que evaluaron humidificadores reutilizables (generalmente bacterias habituales de la flora cutánea). En 2 de ellos se notificaron aislamientos de especies potencialmente patogénicas. No se aisló contaminación microbiana en las muestras procedentes de modelos desechables, independientemente de si fueron utilizados por un único paciente o por varios de forma consecutiva a lo largo del tiempo. Conclusión: Parece existir bajo riesgo de contaminación en humidificadores desechables durante las primeras semanas de uso, pudiendo reutilizarse entre pacientes distintos sin riesgo de contaminación cruzada. Por otro lado, cabe destacar que la manipulación de los humidificadores reutilizables de forma no aséptica puede aumentar la probabilidad de contaminación, por lo que la sustitución de humidificadores reutilizables por modelos desechables podría ser la opción más segura

Aim: To determine the risk of microbiological contamination with hospital use high- and low-flow bubbling humidifiers. Methods: A systematic literature review was carried out in 6 databases. Observational or experimental studies published between 1990 and 2016 were selected, written in English or Spanish, and in which microbiological contamination with hospital use high- and low-flow bubbling humidifiers was investigated. Results: A total of 12 articles were included: 4 analyzed the water from reusable humidifiers, 4 analyzed the water from prefilled system humidifiers, and the rest compared samples from both models. Microbial contamination was observed in all studies in which reusable humidifiers were evaluated, usually involving common bacteria from the skin flora, while potential pathogenic species were notified in 2 studies. No microbial contamination was isolated from reusable humidifiers, regardless of whether they had been consecutively used over time by a single patient or by several patients. Conclusion: On one hand, there seems to be a low risk of contamination during the first weeks of use of prefilled humidifiers, which allows multiple use in different patients, without a risk of cross-contamination. On the other hand, it should be underscored that handling reusable humidifiers without correct aseptic measures can increase the risk of contamination; replacing reusable humidifiers with prefilled models therefore could be the safest option

Microbiological contamination in high and low flow oxygen humidifiers: A systematic review. / Contaminación microbiológica en humidificadores de sistemas de oxigenoterapia de alto y bajo flujo: una revisión sistemática.

AIM: To determine the risk of microbiological contamination with hospital use high- and low-flow bubbling humidifiers. METHODS: A systematic literature review was carried out in 6 databases. Observational or experimental studies published between 1990 and 2016 were selected, written in English or Spanish, and in which microbiological contamination with hospital use high- and low-flow bubbling humidifiers was investigated. RESULTS: A total of 12 articles were included: 4 analyzed the water from reusable humidifiers, 4 analyzed the water from prefilled system humidifiers, and the rest compared samples from both models. Microbial contamination was observed in all studies in which reusable humidifiers were evaluated, usually involving common bacteria from the skin flora, while potential pathogenic species were notified in 2 studies. No microbial contamination was isolated from reusable humidifiers, regardless of whether they had been consecutively used over time by a single patient or by several patients. CONCLUSION: On one hand, there seems to be a low risk of contamination during the first weeks of use of prefilled humidifiers, which allows multiple use in different patients, without a risk of cross-contamination. On the other hand, it should be underscored that handling reusable humidifiers without correct aseptic measures can increase the risk of contamination; replacing reusable humidifiers with prefilled models therefore could be the safest option.

Extending the Use of Disposable Caging Based on Results of Microbiologic Surface Testing.

Prions are proteinaceous infectious agents that are highly resistant to denaturation. Sterilization of prion-contaminated mouse cages requires chemical agents and increased autoclave temperatures that damage traditional cages, thus increasing facility costs. Disposable cages are a possible alternative that might decrease replacement costs without compromising the environment of the mice. We compared our standard protocol of changing traditional cages and bedding once every 2 wk to an experimental protocol using disposable cages in which only the bedding was changed once every 2 wk over an 8-wk period. We hypothesized that disposable cages would retain an acceptable level of cleanliness (measured by ATP swabs and contact plates) for at least 8 wk when bedding is replaced every 14 d. Results from ATP swabs and contact plates showed no difference between the 2 protocols during the 8-wk experiment. Prolonged use (that is, as long as 8 wk) of disposable cages had no additional environmental concerns, compared with traditional cages.

Reprocessing of single-use endoscopic variceal band ligation devices: a pilot study.

Background and study aims The preferred management of bleeding esophageal varices includes endoscopic band ligation. Endoscopic ligation devices (ELDs) are expensive and designed for single use, limiting their uptake in developing countries. We aimed to assess the efficacy of reprocessing ELDs using terminal microbial cultures and adenosine triphosphate (ATP) testing. Materials and methods ELDs were recovered after clinical use and their components (cap, handle, and cord) were subjected to reprocessing. This included manual cleaning, automated high-level disinfection (HLD), and drying with forced air. Using sterile technique, ELD components were sampled for ATP at three stages: before manual cleaning, after manual cleaning, and after HLD. Components were sent to an external laboratory for culturing. Cultures were interpreted as positive upon identification of Gram-negative bacilli. Results A total of 14 clinically used ELDs were studied, and 189 ATP tests and 41 cultures were evaluated. Overall, 95 % (39/41) of components and 86 % (12/14) of ELDs were culture-negative or did not yield Gram-negative bacilli. Two components (5 %; one handle and one cord) harbored Gram-negative bacilli in quantities of 1 CFU per component. There was no apparent correlation between ATP at any juncture of reprocessing and terminal cultures. Conclusions Reprocessing of ELDs is effective, resulting in infrequent and minimal microbial contamination. Microbial culturing can be used to ensure adequacy of ELD reprocessing if pursued. Until reusable ELDs are commercially available, continued efforts to better define the adequacy and long-term effects of reprocessing ELDs are needed.

Disposable Bronchoscope Model for Simulating Endoscopic Reprocessing and Surveillance Cultures.

BACKGROUND Endoscope-associated infections are reported despite following proper reprocessing methods. Microbiological testing can confirm the adequacy of endoscope reprocessing. Multiple controversies related to the method and interpretation of microbiological testing cultures have arisen that make their routine performance a complex target. OBJECTIVE We conducted a pilot study using disposable bronchoscopes (DBs) to simulate different reprocessing times and soaking times and to compare high-level disinfection versus ethylene oxide sterilization. We also reviewed the time to reprocessing and duration of the procedures. METHODS Bronchoscopes were chosen because an alternative disposable scope is commercially available and because bronchoscopes are more prone to delays in processing. Disposable bronchoscopes were contaminated using a liquid bacterial suspension and were then incubated for 1-4 hours. Standard processing and high-level disinfection were performed on 36 endoscopes. Ethylene oxide sterilization was performed on 21 endoscopes. Endoscope cultures were performed using the standard "brush, flush, brush" technique. RESULTS After brushing was performed, a final water-flush culture procedure was the most effective method of detecting bacterial persistence on the disposable scopes. Klebsiella pneumoniae was the most commonly recovered organism after reprocessing. Ethylene oxide sterilization did not result in total elimination of viable bacteria. CONCLUSION Routine endoscopy cultures may be required to assess the adequacy of endoscopic processing. Infect Control Hosp Epidemiol 2017;38:136-142.

Contamination of single-use bronchoscopes in critically ill patients.

Disposable bronchoscopes such as the Ambu aScopeTM 3 are marketed as 'single use' The risks of contamination from prolonged device storage before possible re-use are unknown. Following clinical bronchoscopy in patients whose lungs were mechanically ventilated, 20 aScopeTM 3's bronchoscopes received a standard 'social clean' and were then stored. Subsequent paired saline flush and swab samples were taken at time zero, and at 24 h and 48 h. Positive microbiological cultures were obtained from at least one time point from 16 of the 20 bronchoscopes. Pathogens considered at high risk of causing pneumonia were isolated from seven bronchoscopes, with significant quantities from six of them. Our study demonstrates that aScopeTM 3's should not be re-used on the same patient, as clinically significant growth of micro-organisms occurs frequently, despite adequate social cleaning. Culture of bronchoscopes themselves may be a potentially useful diagnostic tool in the context of pulmonary infection. Our data make it clear that these devices are single use and not single patient use.

Multiple withdrawals from single-use vials: a study on sterility.

BACKGROUND: Reutilization of single-use vials containing medical drugs is still under discussion. This practice has been adopted as a standard to avoid drug wastage, particularly in developing countries and in the aftermath of disasters. Some studies have assessed sterility of medications stored in single-use vials after utilization as multiple doses; however, most of these were limited to one single drug, included a low number of samples and did not consider an intermediate transfer step from the vial to a disposable syringe. The purpose of this study was to assess microbial contamination of samples withdrawn over three days from disposable syringes prepared from single-use vials. METHODS: A prospective sterility study was conducted. A total of 600 initial samples were prepared from six-hundred 10 mL single-use vials of physiological solution into six-hundred 20 mL disposable syringes. Samples were prepared in three different standard operating rooms, on six different days and by the same operator, using basic sterile technique. All syringes were capped, placed together in a non-sterile steel container, covered with a clean drape and stored in the refrigerator at 4°C under non-sterile conditions. Using basic sterile technique, four samples were withdrawn daily and cultured from each syringe over the next 3 days. Microbial growth was examined on Sabouraud agar and chocolate agar culture media. RESULTS: A total of 7200 samples were collected and 14,400 cultures were performed. No evidence of microbial growth in any of the culture media plates was found. CONCLUSION: This study demonstrated that contents initially stored in single-use vials and subsequently transferred into disposable syringes in an operating room using sterile technique, maintain sterility after 4 withdrawals per day for a total of 3 days.

Post-photorefractive keratectomy contact lens microbiological findings of individuals who work in a hospital environment.

OBJECTIVE: To describe the microbiological findings from bandage contact lenses in patients who work in a hospital environment submitted to photorefractive keratectomy (PRK). METHODS: This prospective comparative case series enrolled 43 eyes of 22 volunteers (28.05 ± 3.50 years). Fourteen individuals (n = 27) were health care professionals who work in health care facilities or community physician's offices. Eight individuals (n = 16) were patients who do not work in hospital environment. Photorefractive keratectomy was performed using standard technique, and a silicone hydrogel bandage contact lens was placed on the cornea and evaluated for adequate fit. Seven days after surgery, the bandage lenses were removed and imprinted in the following culture media: blood agar, chocolate agar, anaerobic-selective agar, and Sabouraud agar. When microbial growth was detected, the microorganism was identified, colony-forming units were quantified, and morphology and Gram-staining properties were analyzed. All isolates were tested for susceptibility to various antibiotics. Significance was assessed by Fisher exact test. RESULTS: Microbial growth was detected in 16.27% of all contact lenses samples. No fungi or anaerobes were found. Microbial growth was only observed in bandage lenses removed from patients who work in hospital environments. Most microorganisms found were sensitive to all antibiotics tested. CONCLUSION: These results suggest that working in hospital environments increase contamination of the contact lenses after PRK.

Cleanliness of disposable vs nondisposable electrocardiography lead wires in children.

BACKGROUND: Mediastinitis costs hospitals thousands of dollars a year and increases the incidence of patient morbidity and mortality. No studies have been done to evaluate adenosine triphosphate (ATP) counts on disposable and nondisposable electrocardiography (ECG) lead wires in pediatric patients. OBJECTIVE: To compare the cleanliness of disposable and nondisposable ECG lead wires in postoperative pediatric cardiac surgery patients by measuring the quantity of ATP (in relative luminescence units [RLUs]). ATP levels correlate with microbial cell counts and are used by institutions to assess hospital equipment and cleanliness. METHODS: A prospective, randomized trial was initiated with approval from the institutional review board. Verbal consent was obtained from the parents/guardians for each patient. Trained nurses performed ATP swabs on the right and left upper ECG cables on postoperative days 1, 2, and 3. RESULTS: This study enrolled 51 patients. The disposable ECG lead wire ATP count on postoperative day 1 (median, 157 RLUs) was significantly lower (P < .001) than the count for nondisposable ATP lead wires (median, 610 RLUs). On postoperative day 2, the ATP count for the disposable ECG lead wires (median, 200 RLUs) was also lower (P = .06) than the count for the nondisposable ECG lead wires (median, 453 RLUs). CONCLUSION: Results of this study support the use of disposable ECG lead wires in postoperative pediatric cardiac surgery patients for at least the first 48 hours as a direct strategy to reduce the ATP counts on ECG lead wires.

The silver lining of disposable sporicidal privacy curtains in an intensive care unit.

BACKGROUND: The environment is a well-known source of health care-acquired infection. Because of the known risk of contamination, patient privacy curtains require frequent changes to decrease the risk of spread from patients to curtain and visa versa. METHODS: Fourteen disposable sporicidal privacy curtains were tested from December 2012 to June 2013 while hanging in a busy intensive care unit. Significant bacterial pathogens were identified and total bacteria enumerated as colony-forming units. Antimicrobial activity of curtain swatches was also tested against a range of bacteria in the laboratory. Measurements were recorded as zone of inhibition and contact inhibition. A cost analysis to replace standard curtains with disposable sporicidal curtains was also undertaken. RESULTS: Cultures grew low numbers of skin and environmental microorganisms with no methicillin-resistant Staphylococcus aureus, carbapenem-resistant Enterobacteriaceae, or Clostridium difficile detected. Vancomycin-resistant enterococci were recovered in very low numbers from 2 curtains where vancomycin-resistant enterococci-infected patients had been located. Privacy curtains demonstrated antimicrobial activity against C difficile and 13 additional bacterial pathogens. CONCLUSION: We conclude that disposable sporicidal privacy curtains are cost-effective and best replaced at 6 months in a high-risk area such as an intensive care unit.

Safety and efficacy of a novel disposable sheathed gastroscopic system in clinical practice.

BACKGROUND AND AIM: Endoscopic examinations carry a potential risk of cross-infection, and the traditional reprocessing method is time consuming. We evaluated the safety and efficacy of a novel disposable sheathed gastroscope system in clinical practice in comparison with the conventional gastroscope. METHODS: There were two phases in the study. In phase 1, 20 patients with hepatitis B were randomized into two groups: the sheathed group was examined with the novel disposable sheathed gastroscope (n = 10) and the conventional group with the conventional gastroscope (n = 10). Microbiologic tests were performed on each endoscope afterwards. In the second phase, 1120 patients were randomized again into the same two groups with 568 and 552 patients in the sheathed group and the conventional group, respectively. The time duration of the endoscopic procedure and reprocessing were measured. The pathology detection rate of endoscopic examinations, the patients' subjective feelings, and problems occurred during procedures were also recorded. RESULTS: The total instrument turn-around time in the phase 2 sheathed group (9.9 ± 1.3 min) was significantly shorter than the conventional group (39.0 ± 1.4 min, P = 0.000). The mean procedural time was slightly longer in the sheathed group than in the conventional group (4.9 ± 1.4 vs 4.1 ± 1.3 min, P = 0.000). However, the duration of endoscopic reprocessing was much shorter (4.9 ± 0.2 vs 35 ± 0.2 min, P = 0.000). No significant differences were observed in patient discomfort, optical clarity, or pathology detection rate. There were no complications in either group, and no microbial contamination was detected in phase 1 of the study. CONCLUSIONS: Compared with the conventional gastroscope, the novel disposable sheathed gastroendoscope is safe and more efficient in clinical practice.

A microbiological evaluation of level of disinfection for flexible cystoscopes protected by disposable endosheaths.

BACKGROUND: Flexible cystoscopy is used in urological outpatient departments for diagnostic cystoscopy of bladder cancer and requires a high-level disinfection between each patient. The purpose of this study was to make a microbiological post disinfection efficacy assessment of flexible cystoscopes (FC) using disposable sterile endosheaths. METHODS: One hundred endosheaths underwent a leak-test for barrier integrity after cystoscopy. Microbiological samples from these cystoscopies were obtained; after removal of the endosheath, and after cleaning the scope with a detergent cloth, rinsing with tap water followed by 70% ethanol disinfection and subsequent drying. The number of colony forming units (cfu) from the samples was counted after 72 hours and then divided in three categories, Clean FC (<5 cfu/sample), Critical FC (5-50 cfu/sample) and High-risk FC (>50 cfu/sample). The result was compared with data of 10 years continuous control sampling recorded in the Copenhagen Clean-Endoscope Quality Control Database (CCQCD) and analyzed with a Chi-square test for homogeneity. RESULTS: All 100 endosheaths passed the leak-test. All samples showed a Clean FC and low means of cfu. A query to the CCQCD, showed that 99.8% (1264/1267) of all FC with a built-in work-channel reprocessed in a WD were clean before use. CONCLUSION: The reprocessing of FC using endosheaths, as preformed in this study, provides a patient-ready procedure. The results display a reprocessing procedure with low risk of pathogen transmission, high patient safety and a valid alternative to the recommended high-level disinfection procedure of FC. However, the general impression was that sheaths slightly reduced vision and resulted in some patient discomfort.

A paper-based microbial fuel cell: instant battery for disposable diagnostic devices.

We present a microfabricated paper-based microbial fuel cell (MFC) generating a maximum power of 5.5 µW/cm(2). The MFC features (1) a paper-based proton exchange membrane by infiltrating sulfonated sodium polystyrene sulfonate and (2) micro-fabricated paper chambers by patterning hydrophobic barriers of photoresist. Once inoculum and catholyte were added to the MFC, a current of 74 µA was generated immediately. This paper-based MFC has the advantages of ease of use, low production cost, and high portability. The voltage produced was increased by 1.9 × when two MFC devices were stacked in series, while operating lifetime was significantly enhanced in parallel.

Efficacy of decontamination and sterilization of a single-use single-incision laparoscopic surgery port.

OBJECTIVE: To determine the efficacy of decontamination and sterilization of a disposable port intended for use during single-incision laparoscopy. SAMPLE: 5 material samples obtained from each of 3 laparoscopic surgery ports. PROCEDURES: Ports were assigned to undergo decontamination and ethylene oxide sterilization without bacterial inoculation (negative control port), with bacterial inoculation (Staphylococcus aureus, Escherichia coli, and Mycobacterium fortuitum) and without decontamination and sterilization (positive control port), or with bacterial inoculation followed by decontamination and ethylene oxide sterilization (treated port). Each port underwent testing 5 times; during each time, a sample of the foam portion of each port was obtained and bacteriologic culture testing was performed. Bacteriologic culture scores were determined for each port sample. RESULTS: None of the treated port samples had positive bacteriologic culture results. All 5 positive control port samples had positive bacteriologic culture results. One negative control port sample had positive bacteriologic culture results; a spore-forming Bacillus sp organism was cultured from that port sample, which was thought to be an environmental contaminant. Bacteriologic culture scores for the treated port samples were significantly lower than those for the positive control port samples. Bacteriologic culture scores for the treated port samples were not significantly different from those for negative control port samples. CONCLUSIONS AND CLINICAL RELEVANCE: Results of this study indicated standard procedures for decontamination and sterilization of a single-use port intended for use during singleincision laparoscopic surgery were effective for elimination of inoculated bacteria. Reuse of this port may be safe for laparoscopic surgery of animals.