Sink Drain Research Articles

How Frequently Does Hospitalization of Patients Colonized With Carbapenemase-Producing Enterobacteriaceae Result in Contamination of Hospital Sink Drains?

How Frequently Does Hospitalization of Patients Colonized With Carbapenemase-Producing Enterobacteriaceae Result in Contamination of Hospital Sink Drains?

Electricity production of a microbial fuel cell stack integrated into a sink drain pipe

In this study, five two-chambered microbial fuel cells (MFCs) were hydraulically connected in series to constitute a MFC stack, which was integrated into a sink drain pipe for kitchen wastewater treatment. Performances of the MFC stack operating with artificial and real wastewater were studied. Considering the practical application, the voltage response to different flow rates and temperatures of the substrate was also investigated. It was found that the MFC stack could achieve a reasonable performance, with an average open circuit voltage of 3.44 ± 0.02 V, a peak power of 45.74 ± 1.39 mW (i.e. 809.27 mW/m2) and a coulombic efficiency of 78.2 ± 3.6 %. The MFC performance was disturbed by the flushing process, but could recover after a few minutes. The results also suggest that the MFC stack can operate after flushing by the substrate at 50 °C, above which irreversible performance deterioration was observed. The proposed MFC stack is expected to serve as a potential power source for lighting and low-power devices, especially in off-grid rural areas.

Outbreak of Extended-Spectrum Beta-Lactamase Producing Enterobacter cloacae with High MICs of Quaternary Ammonium Compounds in a Hematology Ward Associated with Contaminated Sinks.

Objective: To investigate an outbreak of extended-spectrum beta-lactamase (ESBL) producing Enterobacter cloacae that occurred in the Hematology ward (24-bed unit) of the François Mitterrand University Hospital (Dijon, France) between January 2011 and December 2013. The outbreak involved 43 patients (10 infected and 33 colonized).Design: We performed environmental analysis to detect multiresistant E. cloacae for comparison with clinical isolates (genotyping by pulsed-field gel electrophoresis and MLST as well as ESBL-typing) and determined the MICs of the quaternary ammonium compounds (QACs) alkyldimethylbenzylammonium chloride (ADBAC) and didecyldimethylammonium chloride (DDAC). A bleach-based cleaning-disinfection program was implemented in December 2012 after mechanical removal of the biofilm in all sinks.Results: We have detected 17 ESBL-producing E. cloacae in patients sink drains, shower drains and medical sink drains. Sequencing of the bla genes performed on 60 strains recovered from patients and environment (n = 43 clinical and n = 17 environmental) revealed that bla CTX−M15 was predominant (37 isolates) followed by bla CTX−M9 plus bla SHV−12 (20 isolates). We observed a great diversity among the isolates: 14 pulsotypes (11 STs) in clinical isolates and 9 pulsotypes (7 STs) in environmental isolates. Six pulsotypes were identical between clinical and environmental isolates. MICs of the quaternary ammonium compounds widely used for disinfection were very high in clinical and environmental isolates. Immediately after the implementation of the disinfection program we noticed a substantial fall in cases number. Our findings demonstrate the role of drains as important reservoir of ESBL-producing E. cloacae and highlight the necessity to settle drains accessible to achieve correct cleaning as well as to use disinfectant with proved activity against nosocomial pathogens.

Acetic acid as a decontamination method for sink drains in a nosocomial outbreak of metallo-β-lactamase-producing Pseudomonas aeruginosa

Pseudomonas aeruginosa may colonize water systems via biofilm formation. In hospital environments, contaminated sinks have been associated with nosocomial transmission. Here we describe a prolonged outbreak of a metallo-β-lactamase-producing P.aeruginosa (Pae-MBL) associated with sink drains, and propose a previously unreported decontamination method with acetic acid. To describe a nosocomial outbreak of Pae-MBL associated with hospital sink drains and to evaluate acetic acid as a decontamination method. The outbreak was investigated by searching the microbiology database, microbiological sampling and strain typing. Antibacterial and antibiofilm properties of acetic acid were evaluated invitro. Pae-MBL-positive sinks were treated with 24% acetic acid once weekly and monitored with repeated cultures. Fourteen patients with positive cultures for Pae-MBL were identified from 2008 to 2014. The patients had been admitted to three wards, where screening discovered Pae-MBL in 12 sink drains located in the patient bathrooms. Typing of clinical and sink drain isolates revealed identical or closely related strains. Pae-MBL biofilm was highly sensitive to acetic acid with a minimum biofilm eradication concentration of 0.75% (range: 0.19-1.5). Weekly treatment of colonized sink drains with acetic acid resulted in negative cultures and terminated transmission. Acetic acid is highly effective against Pae-MBL biofilms, and may be used as a simple method to decontaminate sink drains and to prevent nosocomial transmission.

Carbapenemase-bearing Klebsiella spp. in sink drains: investigation into the potential advantage of copper pipes

Sink drains have long been known to harbour pathogenic bacteria and efforts such as heated sink traps have been made to control them. Sink outlet pipes have been implicated in outbreaks of infection by multi-resistant Klebsiella pneumoniae. To investigate whether a change to copper pipes might prevent cross-infection, sections of standard sink outlet pipe were left in containers of water to which multi-resistant human strains of K. pneumoniae had been added. Bacterial counts from the water of containers to which copper pipe had been added were lower than those from containers to which PVC (polyvinyl chloride) pipe had been added.

Detection of human pathogenicFusariumspecies in hospital and communal sink biofilms by using a highly specific monoclonal antibody

The fungus Fusarium is well known as a plant pathogen, but has recently emerged as an opportunistic pathogen of humans. Habitats providing direct human exposure to infectious propagules are largely unknown, but there is growing evidence that plumbing systems are sources of human pathogenic strains in the Fusarium solani species complex (FSSC) and Fusarium oxysporum species complex (FOSC), the most common groups infecting humans. Here, a newly developed Fusarium-specific monoclonal antibody (mAb ED7) was used to track FSSC and FOSC strains in sink drain biofilms by detecting its target antigen, an extracellular 200 kDa carbohydrate, in saline swabs. The antigen was detectable in 52% of swab samples collected from sinks across a University campus and a tertiary care hospital. The mAb was 100% accurate in detecting FSSC, FOSC, and F. dimerum species complex (FDSC) strains that were present, as mixed fungal communities, in 83% of sink drain biofilms. Specificity of the ELISA was confirmed by sequencing of the internally transcribed spacer 1 (ITS1)-5.8S-ITS2 rRNA-encoding regions of culturable yeasts and molds that were recovered using mycological culture, while translation elongation factor (TEF)-1α analysis of Fusarium isolates included FSSC 1-a, FOSC 33, and FDSC ET-gr, the most common clinical pathotypes in each group.

QPP-MAC: A Greener Algorithm for Single Sink Wireless Sensor Networks

Wireless sensor networks (WSN) with a single data collection node or ‘sink’ play major role in data acquisition (DAQ) and control systems such as smart buildings. These ‘many-to-one’ networks have unique challenges in addition to regular energy concern issues. For example, nodes closer to the sink experience high traffic and drain faster. In this paper, a priority based, distributed, quasi-planned Medium Access Control (MAC) scheduling algorithm is suggested for such network architectures. The proposed Quorum-Pattern-Priority (QPP) MAC approach reduces energy wastage due to idle-listening, overhearing and transmission of unnecessary overhead. The algorithm is tested with multiple sensor classes each with a different data trans-mission pattern. The proposed protocol shows significantly low energy consumption while providing almost ideal throughput for steady traffic. The algorithm also better handles varying traffic compared to many conventional fixed scheduling algorithms.

DNA Persistence in a Sink Drain Environment.

Biofilms are organized structures composed mainly of cells and extracellular polymeric substances produced by the constituent microorganisms. Ubiquitous in nature, biofilms have an innate ability to capture and retain passing material and may therefore act as natural collectors of contaminants or signatures of upstream activities. To determine the persistence and detectability of DNA passing through a sink drain environment, Bacillus anthracis strain Ames35 was cultured (6.35 x 107 CFU/mL), sterilized, and disposed of by addition to a sink drain apparatus with an established biofilm. The sink drain apparatus was sampled before and for several days after the addition of the sterilized B. anthracis culture to detect the presence of B. anthracis DNA. Multiple PCR primer pairs were used to screen for chromosomal and plasmid DNA with primers targeting shorter sequences showing greater amplification efficiency and success. PCR amplification and detection of target sequences indicate persistence of chromosomal DNA and plasmid DNA in the biofilm for 5 or more and 14 or more days, respectively.

Lesser-known or hidden reservoirs of infection and implications for adequate prevention strategies: Where to look and what to look for.

In developing hygiene strategies, in recent years, the major focus has been on the hands as the key route of infection transmission. However, there is a multitude of lesser-known and underestimated reservoirs for microorganisms which are the triggering sources and vehicles for outbreaks or sporadic cases of infection. Among those are water reservoirs such as sink drains, fixtures, decorative water fountains and waste-water treatment plants, frequently touched textile surfaces such as private curtains in hospitals and laundry, but also transvaginal ultrasound probes, parenteral drug products, and disinfectant wipe dispensers. The review of outbreak reports also reveals Gram-negative and multiple-drug resistant microorganisms to have become an increasingly frequent and severe threat in medical settings. In some instances, the causative organisms are particularly difficult to identify because they are concealed in biofilms or in a state referred to as viable but nonculturable, which eludes conventional culture media-based detection methods. There is an enormous preventative potential in these insights, which has not been fully tapped. New and emerging pathogens, novel pathogen detection methods, and hidden reservoirs of infection should hence be given special consideration when designing the layout of buildings and medical devices, but also when defining the core competencies for medical staff, establishing programmes for patient empowerment and education of the general public, and when implementing protocols for the prevention and control of infections in medical, community and domestic settings.

A Death Involving Hydrogen Sulfide Exposure from a Domestic Sink Drain

A Death Involving Hydrogen Sulfide Exposure from a Domestic Sink Drain A case of 44‐year old white asthmatic female is reported who died after attempting to unclog a kitchen sink drain. A strong odor of “sewer gas” was detected in the residence. Autopsy revealed a dusky gray‐green discoloration to the gray matter of the cerebral hemispheres which was indicative of hydrogen sulfide exposure. Toxicology drug screening detected the presence of amphetamines, cannabinoids and ethanol. The femoral blood thiosulfate concentration was 15.5 µg/mL and sulfhemoglobin concentration was 6.3%. Urine thiosulfate was determined to be 9.4 mg /g creatinine. Cause of death was ruled as the result of hydrogen sulfide intoxication with methamphetamine abuse and asthma as contributing factors.

Achromobacter xylosoxidans: A Rare Infection Masquerading as Metastatic Hepatic Malignancy

Introduction: The incidence of pyogenic liver abscesses is estimated to be 3.6 per 100,000 in the United States. Achromobacter xylosoxidans (AX) is an aerobic, motile, gram-negative bacillus, often misidentified as Pseudomonas aeruginosa, that can be isolated in hospital and domestic sink drains. Bacteremia and bronchiolitis due to AX has been described in patients after liver transplantation for Caroli’s disease and cystic fibrosis, respectively. Although it may be found occasionally in the bile, it is very rarely the cause of liver abscess in immunocompetent patients. Rare cases of liver and intraabdominal abscesses caused by AX have been described in association with prior cholecystectomy. We describe a rare case of AX infection mimicking hepatic malignancy in an immunocompetent patient after cholecystectomy and ERCP. A 66-year-old female with history of open cholecystectomy for gangrenous cholecystitis, ERCP for gallstone pancreatitis, PPD+, and recent colonoscopy with polypectomy, was admitted for right upper quadrant abdominal pain, nausea, and weight loss. Laboratory work-up showed WBC count of 13 with 77% neutrophils, platelets 575, total bilirubin of 1.4 mg/dL, and alkaline phosphatase 255 U/L. CT of the abdomen revealed 2 solid masses in the liver. CEA, CA 19-9, AFP, and CA-125 were normal. CT of chest showed only emphysematous changes. Two needle liver biopsies showed fibroinflammatory tissue with focal necrotizing granulomas, and large droplet steatosis, compatible with an infectious process suggestive of AX. The patient was treated with sulfamethoxazole/trimethoprim 800/160 mg, and within 2 weeks, she demonstrated significant improvement in appetite and weight gain. After 6 weeks of therapy, she was asymptomatic with complete resolution of the lesions on repeat MRI. While AX is a ubiquitous waterborne nosocomial organism, it rarely causes infections in immunocompetent hosts. Hepatic involvement may mimic metastatic malignancy and may pose additional diagnostic challenges. It is important to be cognizant of this rare cause of liver abscess in immunocompromized and immunocompetent patients after cholecystectomy and ERCP.

Outbreak of Bacteremia Due toBurkholderia contaminansLinked to Intravenous Fentanyl From an Institutional Compounding Pharmacy

IMPORTANCE Many health care facilities compound medications on site to fulfill local demands when customized formulations are needed, national supply is critically low, or costs for manufactured pharmaceuticals are excessive. Small, institutional compounding facilities may perform the same high-risk procedures as large distributors of compounded medications. OBJECTIVES To investigate an outbreak related to contamination of compounded sterile preparations and to determine processes to prevent future outbreaks. DESIGN, SETTING, AND PARTICIPANTS We performed an outbreak investigation of inpatients at Duke University Hospital from August 31 through September 6, 2012. The investigation included a case-control study, compounding facility inspection and environmental sampling, observation of a mock compounding demonstration, and microbiologic and molecular testing of sequestered medication. EXPOSURES Intravenous fentanyl prepared by an institutional compounding pharmacy. MAIN OUTCOMES AND MEASURES Microbiologic and molecular evidence of contamination of a compounded sterile preparation and failure of routine sterility testing. RESULTS Blood cultures of 7 patients during a 7-day period at Duke University Hospital yielded pan-susceptible Burkholderia cepacia complex bacteria. The risk factor common to all patients was receipt of continuous fentanyl infusion prepared by our institutional compounding pharmacy (odds ratio, 11.22; 95% CI, 2.09-∞; P = .01). The outbreak was terminated after sequestration of compounded fentanyl. An intensive evaluation of the compounding facility, its practice, and its procedures was completed. Investigators evaluated the clean room, collected targeted microbiologic samples within the compounding pharmacy environment, and observed a mock demonstration of compounding practice. The B cepacia complex was found in the anteroom sink drain and pH probe calibration fluid from the compounding clean room. Multiple microbiologic analyses of sequestered fentanyl initially failed. Ultimately, a batched, vacuum-assisted filtration method produced B cepacia complex from a single lot. Molecular analyses using repetitive element polymerase chain reaction and pulsed-field gel electrophoresis confirmed a clonal Burkholderia contaminans strain from patients, fentanyl, and environmental samples. CONCLUSIONS AND RELEVANCE An outbreak of B contaminans bacteremia was linked to contamination of locally compounded intravenous fentanyl. Health care facilities that house institutional compounding facilities must be vigilant in efforts to prevent, recognize, and terminate medication-related outbreaks.

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There are very little attempts of DEM evaluation in such a disturbed or discontinuous surface (e.g., in tillage area). Present study aims to evaluate common interpolation methods (triangulation, nearest neighbor, natural neighbor, minimum curvature, multiquadratic radial basis function (MRBF), ordinary kriging, and inverse distance weight) in representing the detail topography of two different tillage types, namely bench terrace and furrow. Evaluation procedure was conducted through a stepwise analysis by using combination between the accuracy level (coefficient of determination (R2), mean error (ME) and standard deviation error (S)) and the shape similarity analysis. This study also shows the application of break-line function during the interpolation process in order to optimize some interpolation methods and the usage of drainage sink area as another step in evaluating DEM quality. To achieve the aim of this study, two field-size of dry-land agriculture (tegalan) were observed by using a set of total station Nikon DTM 322 with 3” angle accuracy. These plots, namely Tieng (1652 m²) and Buntu (673 m²), are situated in the upper part of Wonosobo District, Central Java Province, Indonesia. Tieng plot represents the bench terrace system embedded with stones on its terrace risers and showing relatively smooth ground surface. On the other side, Buntu plot shows the ridges and furrows system that lays perpendicularly to the contour lines. In terms of R², ME and S, there were slight differences in results between each method, except the multiquadratic radial basis function which was failed to generate terrace form in Tieng. The final result shows that triangulation is the best fit method followed by natural neighbour at representing the bench terraces in Tieng plot. In the case of furrow in Buntu plot, natural neighbour is the most accurate method. Despite its superiority at representing the bench terrace, triangulation has larger sink drainage area compared to natural neighbour. This study has confirmed the robustness of a stepwise analysis between quantitative and qualitative assessment techniques for DEM accuracy. A fine value of quantitative parameter does not necessarily mean that it will fairly possess a good spatial accuracy.

Wastewater drainage system as an occult reservoir in a protracted clonal outbreak due to metallo-β-lactamase-producing Klebsiella oxytoca

AbstractWe describe the epidemiology of a protracted nosocomial clonal outbreak due to multidrug-resistant IMP-8 producing Klebsiella oxytoca (MDRKO) that was finally eradicated by removing an environmental reservoir. The outbreak occurred in the ICU of a Spanish hospital from March 2009 to November 2011 and evolved over four waves. Forty-two patients were affected. First basic (active surveillance, contact precautions and reinforcement of surface cleaning) and later additional control measures (nurse cohorting and establishment of a minimum patient/nurse ratio) were implemented. Screening of ICU staff was repeatedly negative. Initial environmental cultures, including dry surfaces, were also negative. The above measures temporarily controlled cross-transmission but failed to eradicate the epidemic MDRKO strain that reappeared two weeks after the last colonized patients in waves 2 and 3 had been discharged. Therefore, an occult environmental reservoir was suspected. Samples from the drainpipes and traps of a sink were positive; removal of the sink reduced the rate number but did not stop new cases that clustered in a cubicle whose horizontal drainage system was connected with the eliminated sink. The elimination of the horizontal drainage system finally eradicated the outbreak. In conclusion, damp environmental reservoirs (mainly sink drains, traps and the horizontal drainage system) could explain why standard cross-transmission control measures failed to control the outbreak; such reservoirs should be considered even when environmental cultures of surfaces are negative.

Experimental and theoretical study of counter-current oil–water separation in wells with in-situ water injection

Abstract The study investigates a counter-current gravity separation in a downwards-flowing mixture of (up to 3%) oil in water. At much higher oil fraction, the separation is a basis for the conventional downhole oil–water separation (DOWS) where the whole oil and water separate in the well. In contrast, the counter-current separation of a very small oil content is needed in the new “downhole water loop” technique (DWL) prior to injecting the oil-free water in-situ. In the DWL triple-completed wells, the top completion produces oil and only trace of the oil contaminates the water drained by the lower “water sink” completion and is re-injected in-situ using the (third) bottom completion. A drift-flux concept was used to develop an empirical model for predicting the oil droplets raise velocity at different water flow velocities. The model was derived from experiments using seven different oils with a wide range of density, viscosity and interfacial tension values. The experiments monitored oil droplets ejected from a single perforation into the stream of water flowing downwards at various velocities. The results show that the oil–water interfacial tension is the most important factor in the separation process, as it controls the oil droplet size. This observation significantly simplifies the model by replacing the droplet size (most difficult to measure) with a correlation based on interfacial tension developed using the experimental results. The new model also considers the effect of oil viscosity that has been ignored in the co-current separation studies. (Our results reveal over 10% contribution of the viscosity effect to the counter-current separation process.) A practical finding in this study is the 0.33 ft/s (0.1 m/s) value of critical maximum water velocity for counter-current oil separation. In a real DWL well, this value corresponds to a point in the perforated well section above which separation takes place. It is also shown how oil separation could be predicted from a given water sink completion length and drainage–injection rate.

Clonally related Burkholderia contaminans among ventilated patients without cystic fibrosis

We investigated a cluster of 10 Burkholderia cepacia complex-positive cultures among ventilated patients and those with a tracheostomy in an acute care hospital. Isolates from 5 patients had outbreak-strain-related Burkholderia contaminans. Isolates of B. cepacia complex unrelated to the outbreak strain were cultured from a sink drain. The investigation identified practices that might have led to contamination of patient respiratory care supplies with tap water, which might have contributed to the cluster.

Pseudomonas aeruginosa outbreak linked to sink drainage design

Abstract Background This paper describes an outbreak of Pseudomonas aeruginosa (PAE) that occurred in a haematology ward between 8 January and 24 March 2009. Four patients had healthcare-associated infections due to PAE which was recovered in the groin, blood and perianal tissue. Aim This report highlights the risks associated with the use of sinks and outlines the approach used to manage the outbreak. Methods Subsequent investigations showed that a contaminated sink drainage system represented the possible source of spread. Of a total of 21 environmental samples taken, two samples from the sink drainage system showed a similar susceptibility pattern as the patients involved in the outbreak. Four cycles of disinfection of the sink drainage systems were attempted with various modalities. Findings PAE contamination of the sink drains at the multiple grooves in the drains proved difficult to disinfect adequately, despite using several cleaning protocols. The outbreak was finally terminated following a change in the sink drainage system to one without grooves, hence preventing any further PAE colonisation. Conclusion Our experience demonstrated that the design of the sink drainage system may be a potential source of PAE contamination for an immunocompromised patient.

Genome of the pathogen Porphyromonas gingivalis recovered from a biofilm in a hospital sink using a high-throughput single-cell genomics platform

Although biofilms have been shown to be reservoirs of pathogens, our knowledge of the microbial diversity in biofilms within critical areas, such as health care facilities, is limited. Available methods for pathogen identification and strain typing have some inherent restrictions. In particular, culturing will yield only a fraction of the species present, PCR of virulence or marker genes is mainly focused on a handful of known species, and shotgun metagenomics is limited in the ability to detect strain variations. In this study, we present a single-cell genome sequencing approach to address these limitations and demonstrate it by specifically targeting bacterial cells within a complex biofilm from a hospital bathroom sink drain. A newly developed, automated platform was used to generate genomic DNA by the multiple displacement amplification (MDA) technique from hundreds of single cells in parallel. MDA reactions were screened and classified by 16S rRNA gene PCR sequence, which revealed a broad range of bacteria covering 25 different genera representing environmental species, human commensals, and opportunistic human pathogens. Here we focus on the recovery of a nearly complete genome representing a novel strain of the periodontal pathogen Porphyromonas gingivalis (P. gingivalis JCVI SC001) using the single-cell assembly tool SPAdes. Single-cell genomics is becoming an accepted method to capture novel genomes, primarily in the marine and soil environments. Here we show for the first time that it also enables comparative genomic analysis of strain variation in a pathogen captured from complex biofilm samples in a healthcare facility.

Physical and Mathematical Models of Vortex Flows During The Last Stages of Steel Draining Operations from a Ladle

Slag entrainment during steel teeming-drain operations from a steel ladle impacts negatively steel cleanliness and quality. In the present work water modeling and mathematical simulations using a multiphase model for momentum and heat transfer were employed to understand the mechanisms of vortex funnel drain and sink drain flows. The critical bath height for vortex development increases with steel throughput and valve gate opening. Six stages during vortex development are identified, passing from a dimple formation on the bath surface until sink drain which begins when the bath level has the same magnitude as the nozzle diameter. This later drain pattern is independent from any other teeming-draining variable being only a function of the bath height and nozzle diameter; when they are about the same the metal-interface collapses. The temperature gradients originated by the heat losses of the ladle to the surroundings provide buoyancy forces that are large enough to influence liquid motion in the ladle. At large bath levels steel observes long-vertical recirculating flows and at low bath levels these flows change to horizontal-circular recirculating flows that become a seed for later vortex development. These buoyancy forces increase the critical height for vortex development and slag entrainment.

Outbreak of Extended-Spectrum β-Lactamase–producingKlebsiella oxytocaInfections Associated with Contaminated Handwashing Sinks1

Klebsiella oxytoca is primarily a health care-associated pathogen acquired from environmental sources. During October 2006-March 2011, a total of 66 patients in a hospital in Toronto, Ontario, Canada, acquired class A extended-spectrum β-lactamase-producing K. oxytoca with 1 of 2 related pulsed-field gel electrophoresis patterns. New cases continued to occur despite reinforcement of infection control practices, prevalence screening, and contact precautions for colonized/infected patients. Cultures from handwashing sinks in the intensive care unit yielded K. oxytoca with identical pulsed-field gel electrophoresis patterns to cultures from the clinical cases. No infections occurred after implementation of sink cleaning 3×/day, sink drain modifications, and an antimicrobial stewardship program. In contrast, a cluster of 4 patients infected with K. oxytoca in a geographically distant medical ward without contaminated sinks was contained with implementation of active screening and contact precautions. Sinks should be considered potential reservoirs for clusters of infection caused by K. oxytoca.