Disinfection Research Papers - Academia.edu (original) (raw)

No efficient, reliable, and scale independent disinfection methods for toilet waste are available today for safe recycling of plant nutrients. Therefore, two chemical treatment methods, addition of urea or of PAA (a quaternary mixture of 15% peracetic acid, 15% hydrogen peroxide and 30% acetic acid), were evaluated for disinfection of faecal matter.

- by and +1
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- Recycling, Multidisciplinary, Escherichia coli, Salmonella Typhimurium
- by Marita Cantwell
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- Microbiology, Food Safety, Industrial Biotechnology, Food Microbiology
- by Said Ajlouni
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- Microbiology, Industrial Biotechnology, Food Microbiology, SHELF LIFE

Legionella is one of the emerging concerns of water quality in built water environments. Premise plumbing systems are among the recognised sources of infection. In the present study, colonisation of hot water networks in health care facilities, schools, hotels, private residences, office and industrial buildings was investigated. Data was analysed in connection with building and premise plumbing characteristics. Over 60% of all buildings were colonised by Legionella; counts were over 1000 CFU/L in 49%. The most prevalent type was Legionella pneumophila serogroup 2-14, isolated from 75% of the positive samples. Centrally produced hot water was found to be a key risk factor (46% of the samples were positive vs. 16% in individual systems); within this group the type of the building was less relevant. Colonisation levels in schools were similar to hotels or hospitals, representing a previously underestimated risk setting. Systems supplied by water from deep groundwater sources were significantly less likely to be colonised than more vulnerable sources (bank-wall filtration, surface water abstraction or karstic water; 28% vs. 51% positive), regardless of the type of treatment applied, including the presence of disinfection. The aggravating effect of larger, more complex and older buildings on colonisation was also confirmed. The present study represents the first baseline analysis, pre-empting regulation or monitoring requirements for Legionella. The prevalence of legionellae and the identified risk factors are indicative for other settings lacking targeted interventions. The statistically confirmed risk factors can serve as indicators for preliminary risk assessment and the prioritisation of interventions.

- by Zsofia Barna
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- Water, Water Purification, Biology, Medicine

Background: This quantitative microbial risk assessment (QMRA) included problem formulation for fomites and hazard identification for 7 microorganisms, including pathogenic Escherichia coli and E coli 0157:H7, Listeria monocytogenes, norovirus, Pseudomonas spp, Salmonella spp, and Staphylococcus aureus. The goal was to address a risk-based process for choosing the log 10 reduction recommendations, in contrast to the current US Environmental Protection Agency requirements. Method: For each microbe evaluated, the QMRA model included specific dose-response models, occurrence determination of aerobic bacteria and specific organisms on fomites, exposure assessment, risk characterization, and risk reduction. Risk estimates were determined for a simple scenario using a single touch of a contaminated surface and self-inoculation. A comparative analysis of log 10 reductions, as suggested by the US Environmental Protection Agency, and the risks based on this QMRA approach was also undertaken. Results: The literature review and meta-analysis showed that aerobic bacteria were the most commonly studied on fomites, averaging 100 colony-forming units (CFU)/cm 2 . Pseudomonas aeruginosa was found at a level of 3.3 Â 10 À1 CFU/cm 2 ; methicillin-resistant S aureus (MRSA), at 6.4 Â 10 À1 CFU/cm 2 . Risk estimates per contact event ranged from a high of 10 À3 for norovirus to a low of 10 À9 for S aureus. Conclusion: This QMRA analysis suggests that a reduction in bacterial numbers on a fomite by 99% (2 logs) most often will reduce the risk of infection from a single contact to less than 1 in 1 million.

- by Isabelle Papineau
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- Nursing, Risk assessment, Infection Control, Norovirus

Objectives: The aim of this study was to evaluate the effectiveness of different concentrations of Chlorhexidine (CHX) and sodium hypochlorite (NaOCl) in disinfecting contaminated Resilon cones within one minute. Study design: Fifty Resilon cones were divided into seven experimental groups and three control groups of 5 cones each. The cones of experimental groups were contaminated with Entrococcus faecalis and subsequently disinfected with different concentrations of NaOCl or CHX. The cones were then transferred into glass tubes containing thioglycollate media and incubated for 7 days. The tubes were examined for turbidity every 24 hours, and if bacterial growth occurred, samples were plated, incubated, gram stained and observed under microscope to confirm E. faecalis growth. Negative, positive, and washing control groups were also used. Results: All the positive and washing control showed profound E.faecalis growth. All the cones disinfected with CHX showed bacterial growth; however, no E. faecalis growth occurred in any samples disinfected with NaOCl. Conclusion: Sodium hypochlorite, at concentrations of 0.5 to 5.25%, is an effective agent for disinfection of contaminated Resilon cones within one minute; however, chlorhexidine is unable to disinfect Resilon cones during one-minute exposure.

- by Amin Milani and +2
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- Dentistry, Disinfection, Sodium Hypochlorite, Chlorhexidine

One concern with current techniques of UV reactor validation is that they provide only a measure of the mean UV fluence. In this research, the actual fluence distribution of a UV reactor is measured through the use of photochemically... more

Background: Today several methods for decontaminating inner cannulae exist. These methods are not based on scientific data, but often on local clinical tradition. This study compares two different decontamination methods. The aim was to find a practical and safe decontamination method. It is a randomized, single-blinded, comparative crossover study. Methods: Fifty outpatients with long-term tracheostomy with an inner cannula were consecutively included and randomly allocated to begin with one of two different treatment sequences: detergent and chlorhexidine-alcohol (A) or detergent (B). Samples for bacterial culture were taken before and after decontamination, and the number of bacteria colonies was counted. Results: Before decontamination, the inner cannulae grew high numbers of bacteria, which were parts of the normal flora of the upper respiratory tract and did not differ significantly between the two sequences (AB; BA). The primary variable was the culture count value after chlorhexidine-alcohol/detergent (A) and detergent (B). The effects of both methods were larger than expected, and the results showed a nearly total elimination of organisms. The equivalence criterion, ratio of mean colony counts (A/B) .0.8, was met at a significance level of P , 0.001. Conclusions: Cleaning the tracheostomy inner cannula with detergent and water is sufficient to achieve decontamination.

- by Gunilla Björling
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- Nursing, Disinfection, Aged, Public health systems and services research

A microbial survival curve is constructed by plotting the number of recoverable cells or their logarithm vs. the exposure time to the hostile agent, be it high or low temperature, a chemical preservative or disinfectant, etc. Since the recovery is usually done in a medium and under conditions that favor growth, the result is insensitive to whether the counted survivors are intact or injured. If or when both the total number of survivors and those remaining intact follow a Weibullian decay pattern (with different parameters), then the momentary number of injured cells will be the momentary difference between the two. Such a scenario can be easily modeled mathematically and the resulting model enables to simulate a variety of survived-injury patterns in thermal and non-thermal food preservation processes. Under certain conditions according to this model, almost all the survivors would be injured to at least some extent and hence may perish during the food's storage and transportation. Isothermal survival-injury curves generated with the Weibullian model based on the above considerations were in general agreement with published experimental data. In principle, the methodology can be extended to simulate mortality-injury patterns under dynamic conditions, i.e., when the temperature or chemical agent's concentration vary with time. Whether a cell is considered injured depends on the recovery method, e.g., on whether it can or cannot grow in a saline medium. Thus recovery in different media may yield somewhat different quantitative results but very unlikely a qualitatively different pattern. Although the model used was based on that microbial mortality and injury both follow the Weibullian model, very similar results would have been obtained had other survival modes been assumed.

- by Maria Corradini
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- Microbiology, Mathematics, High Pressure, Kinetics

Biofilms have been of considerable interest in the context of food hygiene. Of special significance is the ability of microorganisms to attach and grow on food and food-contact surfaces under favourable conditions. Biofilm formation is a dynamic process and different mechanisms are involved in their attachment and growth. Extracellular polymeric substances play an important role in the attachment and colonization of microorganisms to food-contact surfaces. Various techniques have been adopted for the proper study and understanding of biofilm attachment and control. If the microorganisms from food-contact surfaces are not completely removed, they may lead to biofilm formation and also increase the biotransfer potential. Therefore, various preventive and control strategies like hygienic plant lay-out and design of equipment, choice of materials, correct use and selection of detergents and disinfectants coupled with physical methods can be suitably applied for controlling biofilm formation on food-contact surfaces. In addition, bacteriocins and enzymes are gaining importance and have an unique potential in the food industry for the effective biocontrol and removal of biofilms. These newer biocontrol strategies are considered important for the maintenance of biofilm-free systems, for quality and safety of foods.

- by Ganesh Kumar
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- Microbiology, Biofilms, Control, Industrial Biotechnology

Protothecosis has been reported in humans (gastroenteritis, bursitis, etc.) and in many other animal species. Bovine mastitis represents the main form of occurrence of protothecosis in cattle. Milk as well as dairy products, when contaminated with Prototheca spp., represent a potential means of transmission of this zoonosis. The purpose of this study was to evaluate the susceptibility of forty Prototheca zopfii strains isolated from milk from intramammary infections in dairy cows and also from bulk milk tanks of dairy farms, to the different ratios of temperature/time employed in the thermal treatment of milk: 72-75 degrees C/15 seconds, 72-75 degrees C/20 seconds and 62-65 degrees C/30 minutes. The samples were subjected to these different temperature/time ratios. The evaluation of the thermal susceptibility of the P. zopfii strains showed that 34 strains were resistant in at least one of the tests. The results point out the need to consider the importance of mastitis caused by Pro...

- by Nilson Roberti Benites
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- Plant Biology, Public Health, Bovine Mastitis, Infection

Ready-for-use' instruments from surgical instrument trays were examined after routine cleaning and sterilization in a blinded study. These reprocessed instruments originated from five National Health Service hospital trust sterile service departments in England and Wales. Determination of residual protein and peptide contamination was carried out by acid stripping of the instrument surfaces, hydrolysis of the constituent amino acids and quantitative total amino acid analysis. One hundred and twenty instruments were analysed, and the median levels of residual protein contamination per instrument for the individual trays were 267, 260, 163, 456 and 756 mg. Scanning electron microscopy and energy dispersive X-ray spectroscopic analyses of the instruments showed that tissue deposits were localized on surfaces, but there was no significant correlation between overall protein soiling and instrument complexity. The highest levels of residual contamination were found on instruments used for tonsillectomy and adenoid surgery.

In January 1999, an outbreak of viral gastroenteritis affected more than 300 people who attended a metropolitan concert hall over a 5-day period. Norwalk-like virus (NLV) was confirmed in faecal samples by reverse transcription polymerase chain reaction assay. The index case was a concert attendee who vomited in the auditorium and adjacent male toilet. Gastrointestinal illness occurred among members of 8/15 school parties who attended the following day. Children who sat on the same level of the auditorium as the index case were much more likely to be ill than those seated elsewhere (relative risk 7.1, 95% confidence interval 5.4–9.2, P<0.001). The majority of other reported cases had not been present on the evening of the vomiting incident. Disinfection procedure was poor and the disinfectant used contained no sodium hypochlorite. Transmission most likely occurred through direct contact with contaminated fomites. The outbreak has implications for disinfection procedures following...

- by Diana Westmoreland
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- Epidemiology, Disease Outbreaks, Child, Wales

Human noroviruses (HuNoVs) are the most common cause of acute viral gastroenteritis worldwide and are a leading cause of foodborne disease. Their environmental persistence and purported resistance to disinfection undoubtedly contribute to their success as foodborne disease agents. The purpose of this study was to compare the efficacy of three commonly used disinfectant active ingredients against representative HuNoV strains and cultivable surrogates. Ethanol (50, 70, and 90%), sodium hypochlorite (5, 75, 250, 500, and 1,000 ppm), and a quaternary ammonium compound blend (at 0.1×, 1.0×, and 10× concentrations) were evaluated against two norovirus (NoV) genogroup II strains (GII.2 and GII.4) and two surrogates (feline calicivirus [FCV] and murine norovirus [MNV-1]). Virucidal suspension assays (30-s exposure) were conducted in accordance with ASTM International standard E-1052. Virus inactivation was quantified using reverse transcription quantitative PCR targeting the ORFI-ORFII junc...

- by Baldev Gulati
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- Food Safety, Environmental microbiology, Food, Treatment Outcome

Concern has been rising with the respect to the capability of clinically important bacteria to acquire resistance against antibiotics and disinfectants. This investigation was undertaken to provide information on the sensitivity of methicillin-resistant Staphylococcus aureus (MRSA) to some disinfectants. The isolated PCR genotyped MRSA strains were collected from milk and its surrounding animal milking environment of 4 dairy cattle farms. Five commonly used disinfectants (quaternary ammonium compounds, iodine (Povidone-iodine), Sodium hypochlorite (Chlorine), ethyl alcohol and Chloroxylenol (Dettol) were evaluated at different contact times (5, 10, 15 minutes) and variable concentrations using suspension test for measuring their minimal inhibitory concentrations (MICs) against each isolate. The obtained results of MICs of the five tested disinfectants indicated high sensitivity of MRSA to both QACs and iodine, with MICs of 0.25% within 5 minutes(QACs), and 1.37% within 5 minutes (Iodine) at three tested concentrations and exposure times. Nonetheless, these strains exhibited a significant resistance to both ethyl alcohol and chlorine at different concentrations and contact times. Meanwhile, Dettol inhibited MRSA growth at dilutions (5% & 2.5%) within (5, 15, 20 minutes), however, 1.25% at 5 and 15 minutes was unable to potentiate the antibacterial activities of Dettol against strains tested. The findings of the present study reinforce the importance of disinfection as an integral part of the control policies of MRSA prevention and eradication in dairy farms.

The electrochemical disinfection of germinated brown rice (GBR) circulating water and cooling tower water containing Legionella bacteria was investigated. Results showed the total aerobic plate counts (APC) in the treated GBR circulating water decreased significantly and the turbidity was largely improved at a pulse voltage of 1.0 kV; Legionella bacteria were also disinfected effectively at 1.0 kV. The disinfection was attributed to the synergistic effects of the oxide anode, the electric field, and the radicals formed during the electrochemical treatment. This suggests that electrochemical treatment could be applicable to the disinfection of water from other sources.

- by Keitaro Suzuki
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- Chemistry, Electrochemistry, Water Purification, Medicine

Background: Cost-effectiveness analyses show that chlorhexidineesilver sulfadiazine (CHSS)impregnated catheters reduce catheter-related bloodstream infection (CRBSI) and central venous catheter (CVC)-related costs. However, no studies have reported the efficiency of CHSS-impregnated catheters for venous access when the risk of CRBSI is low; for example, at the subclavian site. This study determined the cost of a CVC, diagnosis of CRBSI, and antimicrobial agents to treat CRBSI; we did not consider the cost of increased hospital stay. Methods: This retrospective study included patients admitted to the intensive care unit at Hospital Universitario de Canarias (Tenerife, Spain) who had a subclavian venous catheter. Results: Patients with CHSS catheters (n ¼ 353) had a lower incidence density of CRBSI (2.12 vs 0 out of 1,000 catheter-days; P ¼ .02) and lower CVC-related cost per catheter-day (3.35 AE 3.75 vs 3.94 AE 9.95; P ¼ .002) than those with standard catheters (n ¼ 518). CHSS-impregnated catheters were associated with a lower risk of CRBSI (exact logistic regression) (odds ratio, 0.10; 95% confidence interval, ÀN to 0.667; P ¼ .008) than standard catheters when controlling for catheter duration. CHSS-impregnated catheters were also associated with a lower CVC-related cost per catheter day than standard catheters (Poisson regression) (odds ratio, 0.85; 95% confidence interval, 0.001-0.873; P < .001). Conclusions: CHSS-impregnated catheters may be efficient in preventing CRBSI in patients with subclavian venous access.

- by Leonardo Lorente
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- Nursing, Medicine, Spain, Disinfectants

Recent research indicated that periopathogens colonize, besides the pockets, also other niches within the oral cavity including: the soft tissues, the saliva, the tongue, and even the tonsils. Since the supragingival plaque and the... more

- by Marc Quirynen
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- Dentistry, Periodontics, Periodontology, Bacteria

Trauma transfusion packages for hemorrhage control consist of red blood cells, plasma, and platelets at a set ratio. Although pathogen reduction improves the transfusion safety of platelet and plasma units, there is an associated reduction in quality. This study aimed to investigate the impact of riboflavin/ultraviolet light-treated plasma or platelets in transfusion trauma packages composed of red blood cell, plasma, and platelet units in a ratio of 1:1:1 in vitro by modeling transfusion scenarios for trauma patients and assessing function by rotational thromboelastometry. Pathogen-reduced or untreated plasma and buffy coat platelet concentrate units produced in plasma were used in different combinations with red blood cells in trauma transfusion packages. After reconstitution of these packages with hemodiluted blood, the hemostatic functionality was analyzed by rotational thromboelastometry. Hemostatic profiles of pathogen-inactivated buffy coat platelet concentrate and plasma ind...

- by Brankica Culibrk
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- Immunology, Quality Control, Plasma, Disinfection

Methods: Eighty patients assigned to 4 groups had swabs of the upper eyelid skin taken before and after face wash with soap and water, and cleansing with Savlon and 5% povidone iodine. Specimens were cultured and Gram stained. Bacterial counts were carried out using standard techniques. Results: Face washing with soap and water increased the proportion of patients with bacterial isolates from 80.0% to 87.5%. The average colony count increased from 187.1 to 318.5 colony units per mL (p 5 0.02). Application of 5% povidone iodine without face washing with soap and water reduced the proportion of patients with bacterial isolates from 82.6% (mean count 196.5) to 28.6% (mean count 34.1) (p 5 0.001); in comparison, the application of 5% povidone iodine after face washing with soap and water reduced the proportion from 71.4% (mean count 133.9) to 40.0% (mean count 69.0) (p 5 0.01). Application of Savlon without face washing with soap and water reduced the proportion of patients with bacterial isolates from 100% (mean count 310.9) to 41.2% (mean count 19.8) (p 5 0.004) compared with the application after face washing, which reduced the proportion from 89.5% (mean count 240.3) to 41.2% (mean count 82.9) (p 5 0.02). Conclusions: Both povidone and Savlon are effective in reducing periocular bacteria in an African setting. Prior face washing with soap and water had no added benefit in reducing bacterial colony count. Objet : Établir l'effet du lavage de la figure à l'eau savonneuse et du nettoyage à l'iode de povidone et au gluconate de cétrimide/chlorhexidine (Savlon) sur les bactéries de la paupière supérieure. Nature : Étude clinique prospective, non randomisée. Participants : Quatre-vingt patients de la clinique oculaire de l'hô pital du Collège universitaire d'Ibadan (Nigéria). Mé thodes : Les 80 patients répartis en 4 groupes ont eu des prélèvements de la peau de la paupière supérieure avant et après le lavage facial à l'eau savonneuse, un nettoyage au Savlon et à l'iode de providone 5 %. Les spécimens ont fait l'objet de culture et de coloration de Gram. Les comptes bactériens ont été faits selon les techniques standard. Ré sultats : Le lavage de la figure à l'eau savonneuse a augmenté la proportion de patients qui avaient des isolats bactériens de 80,0 % à 87,5 %. En moyenne, le compte de la colonie a augmenté de 187,1 à 318,5 unités par mL (p 5 0,02). L'application d'iode de providone 5 % sans lavage de la figure à l'eau savonneuse a réduit la proportion des patients ayant des isolats bactériens, de 82,6 % (moyenne 196,5) à 28,6 % (moyenne 34,1) (p 5 0,001) ; comparativement, l'application d'iode de providone 5 % après le lavage de la figure à l'eau savonneuse a réduit la proportion de 71,4 %) (moyenne 133,9) à 40,0 % (moyenne 69,0) (p 5 0,01). L'application de Savlon sans lavage de la figure à l'eau savonneuse a réduit la proportion des patients avec isolats bactériens de 100 % (moyenne 310,9) à 41,2 % (moyenne 19,8) (p 5 0,004) comparativement à l'application après lavage de la figure, ce qui a réduit la proportion de 89,5 % (moyenne 240,3) à 41,2 % (moyenne 82,9) (p 5 0,02). Conclusions : Le providone et le Savlon sont tous deux efficaces pour réduire les bactéries périoculaires en milieu africain. Le lavage préalable de la figure à l'eau savonneuse n'a pas ajouté d'avantage pour la réduction du compte de la colonie bactérienne.

- by BGK Ajayi
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- Water, Face, Adolescent, Prospective studies

Coagulation MIEX Ò Nanofiltration DBPs a b s t r a c t Potentially the most effective means of controlling disinfection by-products (DBPs) is to remove precursors before disinfection. To understand relationships between physical properties, treatability and DBP formation, nine natural organic matter (NOM) surrogates were studied. Their DBP formation and removal by coagulation, MIEX Ò anion exchange resin and two nanofiltration membranes was measured. Whereas treatability of NOM surrogates was explained in terms of their physicochemical properties, the same was not true of DBP formation. Hence it was not possible to selectively remove compounds which generate high amounts of DBPs. Instead, precursor removal strategies based upon empirical DBP formation potential testing are more apt. Under conditions simulating full-scale performance, MIEX Ò did not offer improved performance over coagulation. A hydrophobic nanofiltration membrane proved successful for removing neutral, hydrophilic surrogates, and hence is also suitable for DBP precursors of this character.

- by Bruce Jefferson
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- Water, Filtration, Nanotechnology, Multidisciplinary

The user has requested enhancement of the downloaded file. All in-text references underlined in blue are added to the original document and are linked to publications on ResearchGate, letting you access and read them immediately. This article appeared in a journal published by Elsevier. The attached copy is furnished to the author for internal non-commercial research and education use, including for instruction at the authors institution and sharing with colleagues.

This prospective study examined bacterial colonization on writing pens touched by healthcare professionals and hospitalized patients with and without cleaning the pen with alcohol-based hand sanitizing agent after each patient visit. A significant reduction in potential healthcare-associated pathogens, especially Gram-positive cocci, was observed in the intervention group.

- by Shashank Ghantoji
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- Control, Prevention, Hospitals, Clinical Microbiology

Background: Postoperative surgical site infections (SSI) are the third most common health care associated infection. Even though several studies have pointed out the benefits of disinfection showers prior to surgery in order to reduce... more

- by Christine Wann-hansson
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- Nursing, Evidence Based Nursing, Baths, Perioperative Nursing

Oregano Water reuse Regrowth Coliform a b s t r a c t

- by Bruce Jefferson
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- Microbiology, Water, Water Reuse, Multidisciplinary

M. Effects of disinfectant fogging procedure on dust, ammonia concentration, aerobic bacteria and fungal spores in a farrowing-weaning room. Abstract Introduction and Objective. In the last decades, large-scale swine production has led to intensive rearing systems in which air quality can be easily degraded by aerial contaminants that can pose a health risk to the pigs and farm workers. This study evaluated the effects of fogging disinfectant procedure on productive performance, ammonia and dust concentration, aerobic bacteria and fungal spores spreading in the farrowing-weaning room. Materials and Method. This trial was conducted in 2 identical farrowing-weaning rooms of a piggery. In both rooms, 30 pregnant sows were lodged in individual cages. At 75 days of age, the piglets were moved to the fattening room. In the treated room, with the birth of the first suckling-pig, the fogging disinfection with diluted Virkon S was applied once a day in the experimental room per 15 minutes at 11:00. The fogging disinfectant treatment was switched between rooms at the end of the first trial period. Temperature, relative humidity, dust (TSP-RF fractions and number of particles), ammonia concentration and aerial contaminants (enterococci, Micrococcaeae and fungal spores) were monitored in both rooms. Results. Ammonia concentration reduction induced by fogging disinfection was estimated 18%, total suspended particles and the respirable fraction were significantly lower in the experimental room. Fungal spores resulted in a significant reduction by the fogging procedure, together with dust respirable fraction and fine particulate matter abatement. Conclusions. The fogging disinfection procedure improved air quality in the piggery, thereby enhancing workers and animals health.

- by Annamaria Costa
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- Environmental microbiology, Environmental Monitoring, Fungi, Animal Husbandry

Objective. This study aimed to evaluate the effectiveness of alternative methods for toothbrush disinfection. Methods. Twohundred eighty toothbrushes were included in the study. The toothbrushes were divided into 7 groups and were contaminated by standardized suspensions of Lactobacillus rhamnosus (L. rhamnosus), Streptococcus mutans (S. mutans), Staphylococcus aureus (S. aureus), and Escherichia coli (E. coli). The following disinfectants were tested: 1% sodium hypochlorite (NaOCl), 100% and 50% white vinegar, microwave (MW) oven, ultraviolet (UV) sanitizer, and mouth rinse-containing propolis (MCP). Data were analyzed with Kruskal Wallis and Dunn's tests. Results. Statistically significant differences were found between different methods and control group for all tested bacteria. There were statistically significant differences between all test groups for all microorganisms. MW was the most effective for L. rhamnosus and 100% white vinegar was the most effective method for S. mutans and S. aureus. NaOCl was the most effective for E. coli. Conclusion. This study showed that 100% white vinegar was considered to be effective for tested microorganisms. Similarly, 1% NaOCl is cost-effective, easily accessible, and comparatively effective for toothbrush disinfection. Because these agents are nontoxic, cost-effective and easily accessible, they may be appropriate for household use. Statistically significant difference < 0.05.

- by Meryem Alkurt and +2
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- Propolis, Escherichia coli, Staphylococcus aureus, Disinfection

Chlorine Ultraviolet light Ozone A B S T R A C T Veterinary antibiotics are widely used at concentrated animal feeding operations (CAFOs) to prevent disease and promote growth of livestock. However, the majority of antibiotics are excreted from animals in urine, feces, and manure. Consequently, the lagoons used to store these wastes can act as reservoirs of antibiotics and antibiotic-resistant bacteria.

- by Melanie Mormile
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- Water, Water Purification, Multidisciplinary, Antibiotic Resistance

The Japanese Dermatological Association determined to prepare the Wound/Burn Guidelines focusing on treatments, catering to needs for the clinical practice of dermatology. Among these guidelines, "Wounds in General" was intended... more

- by Taiki Isei
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- Wound Healing, Japan, Chronic Disease, Disinfection

As cleaning and disinfection is a very important topic for endoscopy units and as many patients ask how endoscopists try to prevent the nosocomial risk posed by the endoscope, the ESGE, in 1993, organized a Guidelines Committee on this important subject. The ESGE Guidelines Committee recently asked all national ESGE Member Societies to provide it with their current cleaning and disinfection standards and guidelines. Their reply gives us a good idea of how responsible all national Member Societies are when it comes to cleaning and disinfection, while also showing us the technical differences, linked to the financial and technical possibilities available, that exist between the individual member states. Please also refer to the Technical Note on Cleaning and Disinfection published by the ESGE Guidelines Committee in this issue of the Endoscopy Journal.

- by jean-francois rey
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- Endoscopy, Europe, Disinfection, Clinical Sciences

Glutaraldehyde is used to disinfect flexible and other heat-sensitive endoscopes often with the aid of automated systems. Mycobacterium chelonae is being isolated with increasing frequency from these washer disinfectors and processed endoscopes. This has, on occasions, led to misdiagnosis and iatrogenic infections. Recent reports suggest that disinfecting machines, on a sessional or regular basis, with 2% glutaraldehyde may have selected and therefore encouraged the growth of strains of Myco. chelonae, possibly in biofilm, with decreasing susceptibility to glutaraldehyde. In view of this, the resistance of three strains of Myco. chelonae var. chelonae (the type strain NCTC 946 and two machine isolates) was tested against 2% glutaraldehyde and a wide range of alternative disinfectants. Disinfectants tested were a chlorine releasing agent, sodium dichloroisocyanurate at 1000 ppm and 10 000 ppm av Cl, 0•35% peracetic acid (NuCidex, Johnson & Johnson), 70% industrial methylated spirit (IMS), 1% peroxygen compound ('Virkon', Antec International) and 10% succine dialdehyde ('Gigasept', Sanofi Winthrop). Suspension and carrier tests were carried out in the presence and absence of an organic load. Results showed the type strain, which had not been exposed to the selective pressure of disinfectant usage, to be very sensitive to most disinfectants with the exception of 1% Virkon. The washer disinfector isolates, on the other hand, were extremely resistant to 2% glutaraldehyde and showed greater resistance to 1% Virkon and 1000 ppm NaDCC. Purchasing machines in which the entire fluid pathways, including those for delivering rinse water, are disinfected with an appropriate agent during each cycle are preferred. If this is not possible then sessional cleaning and disinfection at the start of each day and regular maintenance should prevent biofilm formation and contamination with disinfectant-resistant strains of mycobacteria. In addition to machine disinfection, the use of sterile or bacteria-free (filtered ³0•45mm) water is essential for bronchoscopes and all invasive endoscopes. If there is doubt over the effectiveness of the machine disinfection procedure or water quality, the channels and surfaces of endoscopes may be rinsed with 70% IMS after automated processing.

- by Adam Fraise
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- Biology, Applied microbiology, Medicine, Multidisciplinary

ority of dialyzer reuse versus single use when assessing the mortality of patients with end-stage renal disease. Studies of higher quality, including randomized clinical trials, are required to provide conclusive evidence regarding the... more

- by Tais Galvao
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- End Stage Renal Disease, Statistical Significance, American, Disinfection

Disinfection by-products (DBPs) are produced as a result of disinfecting water using various treatment methods. Over the years, chlorine has remained the most popular disinfecting agent due to its ability to kill pathogens. However, in 1974, it was discovered that the superchlorination of drinking water resulted in the production of chloroform and other trihalomethanes. Since then hundreds of additional DBPs have been identified, including haloacetic acids and haloacetonitriles with very little or no toxicological data available, thus necessitating the use of additional methods for hazard estimation. Quantitative Structure Toxicity Relationship (QSTR) is one such method and utilizes a computer-based technology to predict the toxicity of a chemical solely from its molecular attributes. The current research was conducted utilizing the TOPKAT ® /QSTR software package which is comprised of robust, cross-validated QSTR models for assessing mutagenicity, rodent carcinogenicity (female/male; rat/mouse), developmental toxicity, skin sensitization, lowest-observed-adverse-effect level (LOAEL), fathead minnow LC 50 , rat oral LD 50 and Daphia magna EC 50 . A total of 252 DBPs were analyzed for the likelihood that they would produce tumors and developmental effects using the carcinogenicity and developmental toxicity submodels of TOPKAT ® . The model predictions were evaluated to identify generalizations between the functional groups (e.g. alcohols, acids, etc.) and specific toxic endpoints. Developmental toxicity was identified as an endpoint common to the majority of aliphatic mono-and dicarboxylic acids, aliphatic halogenated and non-halogenated ketones, and aliphatic haloacetonitriles. In the case of the carcinogenicity submodels, most aliphatic aldehydes were identified as carcinogens only in the female mouse submodel. The majority of the aliphatic and aromatic dicarboxylic acids were identified as carcinogens in the female rat submodel. All other functional groups examined were largely predicted as non-carcinogens in all the cancer submodels (i.e. male/female rats and mice). The QSTR results should aid in the prioritization for evaluation of toxic endpoints in the absence of in vivo bioassays.

- by C. Moudgal
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- Algorithms, Toxicology, Water Supply, Mice

This study evaluated the antibacterial activity of Rosmarinus officinalis extract and its potential for disinfecting guttapercha (GP) cones. In the first experiment, a hydro-alcoholic extract of Rosmarinus officinalis (leaves) in a dilution ratio of 10% m/v was tested against Enterococcus faecalis by using the disk diffusion method. Positive and negative controls were 70% cereal alcohol and antibiotics, respectively. The procedures were performed in triplicate, and the diameters of the zones of growth inhibition were measured with a caliper after 24 h at 37 degrees C. In the second experiment, the disinfection procedures were evaluated on GP cones artificially contaminated with Enterococcus faecalis. The R. officinalis extract was compared with 2% chlorhexidine digluconate and 2.5% sodium hypochlorite, using a direct exposure test (5 min treatment). Sterilized and non-disinfected cones were used as negative and positive controls, respectively. After 24 h of incubation, bacterial cou...

- by Sérgio Nobre
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- Dentistry, Disinfection, Plant extracts, Rosmarinus

There are few suitable techniques available to sterilize biodegradable polyester three-dimensional tissue engineering sca!olds because they are susceptible to degradation and/or morphological degeneration by high temperature and pressure. We used a novel poly(lactide-co-glycolide) sca!old (Osteofoam2+) to determine the optimal sterilization procedure * i.e. a sterile product with minimal degradation and deformation. Initial studies, found that an argon plasma created at 100 W for 4 min was optimal for sterilizing Osteofoam2+ sca!olds without a!ecting their morphology. The RFGD plasma sterilization method was compared to two well-established techniques * ethylene oxide (ETO) and-irradiation ()-which were in turn compared to disinfection in 70% ethanol. Disinfection in 70% ethanol serves as a useful control because it a!ects neither the morphology nor the molecular weight of the polymer; yet, ethanol is unsuitable as a sterilization method because it does not adequately eliminate hydrophilic viruses and bacterial spores. The three sterilization techniques, ETO, and RFGD plasma, were compared in terms of their immediate and long-term e!ects on the dimensions, morphology, molecular weight and degradation pro"le of the sca!olds. Sca!olds shrank to &60% of their initial volume after ETO sterilization whereas their molecular weight (Mw) decreased by &50% after-irradiation. Thus, both ETO and-irradiation posed immediate problems as sterilization techniques for 3-D biodegradable polyester sca!olds. During the in vitro degradation study, all sterilized samples showed advanced morphological and volume changes over time relative to ethanol (EtOH) disinfected samples, with the greatest changes observed for-irradiated samples. ETO, RFGD plasma sterilized and EtOH disinfected samples showed similar changes in Mw and mass over the 8-week time frame. Overall, of the three sterilization techniques studied, RFGD plasma was the best.

- by John Davies
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- Materials Science, Biomedical Engineering, Biomaterials, Scanning Electron Microscopy

QUESTION 1A: Is there a role for preoperative skin cleansing with an antiseptic? Consensus: Yes. Preoperative cleansing of the skin with chlorhexidine gluconate (CHG) should be implemented. In the presence of a sensitivity to CHG, or when... more

- by R. Morgan-Jones
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- Biomedical Engineering, Orthopaedic, Skin Care, Skin

Needleless connectors, including the standard split septum and the luer-activated mechanical valve connectors, have been introduced into clinical practice to eliminate the risk of needlestick injuries by avoiding the use of needles when accessing the intravascular catheters. Negative and positive displacement mechanical valves have been associated with increased rates of catheter-related bloodstream infections as compared with split septum connectors. Based on available data, split septum connectors should be preferentially used instead of mechanical valves. Adequate disinfection by scrubbing the access port preferably with chlorhexidine is recommended to minimize the risk of catheter microbial contamination along with proper infection control practices. Large prospective randomized clinical trials are needed to evaluate further the possible causes and effects of different types of mechanical valve needleless connectors on bloodstream infections.

- by Nabil Khalidi
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- Nursing, Control, Prevention, Catheterization

We report an outbreak of norovirus gastroenteritis occurring concurrently over two wards. Environmental cleaning was managed using two different methodologies: one ward utilized the traditional 2-step method, the other using microfiber-steam technology. Environmental cleaning using the microfiber-steam technology proved to be an effective and efficient cleaning methodology, appropriate for use during an outbreak situation.

- by Rhonda Stuart
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- Nursing, Disease Outbreaks, Infection Control, Norovirus
- by Sa Chen
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- Water Purification, Hospital Infection, Disease Outbreaks, Infection Control

Aerobic mesophilic counts (AMC), coliform (CC) and coliform resuscitation counts (CRCs) were obtained by swabbing 50 cm 2 areas at three sites (ham, belly and neck) on pig carcasses, after each of seven stages of the slaughter/dressing process (bleeding, scalding, dehairing, singeing, polishing, evisceration and chilling). In most cases, there were no statistical differences ( P>0.05) among the counts derived by these three methods. Reductions in counts at individual sites were observed after scalding (3.5 log 10 cfu cm À 2 ), and singeing (2.5 log 10 cfu cm À 2 ). Increases in counts at individual sites were observed after dehairing (2.0 log 10 cfu cm À 2 ) and polishing (1.5 log 10 cfu cm À 2 ). The incidence of Salmonella on pig carcasses was also obtained by swabbing the outside surfaces of 100 half carcasses. Information on the incidence of Salmonella in scald tank water (108 samples) was also investigated. Carcass swabs and scald tank water were examined for the presence of Salmonella using standard enrichment methods. Salmonella were detected on 31% of carcasses immediately after bleeding, 7% of carcasses immediately after dehairing and evisceration, and 1% of carcasses immediately after scalding. Serovars included Salmonella Typhimurium, Salmonella Hadar, Salmonella Infantis and Salmonella Derby. No Salmonella were recovered from samples of scald tank water. The impact of pig slaughter/dressing processes on carcass microbiology and their potential use as critical control points (CCPs) during pork production are discussed. D

- by Ian Blair
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- Microbiology, Industrial Biotechnology, Food Microbiology, Salmonella Typhimurium

Food allergies affect an estimated 10 to 12 million people in the United States. Some of these individuals can develop life-threatening allergic reactions when exposed to allergenic proteins. At present, the only successful method to manage food allergies is to avoid foods containing allergens. Consumers with food allergies rely on food labels to disclose the presence of allergenic ingredients. However, undeclared allergens can be inadvertently introduced into a food via cross-contact during manufacturing. Although allergen removal through cleaning of shared equipment or processing lines has been identified as one of the critical points for effective allergen control, there is little published information on the effectiveness of cleaning procedures for removing allergenic materials from processing equipment. There also is no consensus on how to validate or verify the efficacy of cleaning procedures. The objectives of this review were (i) to study the incidence and cause of allergen ...

- by Silvia Albillos
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- Food, Multidisciplinary, United States, Allergens

Biofilms are considered a significant health risk in the food and dairy industries because they can harbor pathogens, and direct contact with them can lead to food contamination. Biofilm control is often performed using strong oxidizing... more

- by Paul Bishop
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- Biofilms, Applied microbiology, Multidisciplinary, Chlorine dioxide

Increased attention has been focused on disinfection by housekeepers, but few data are available on disinfection of equipment by nurses. We used adenosine triphosphate bioluminescence assays and aerobic cultures to assess the cleanliness of portable medical equipment disinfected by nurses between each patient use. We found that the equipment was not being disinfected as per protocol and that education and feedback to nursing are warranted to improve disinfection of medical equipment.

- by Nancy Havill
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- Nursing, Infection Control, Disinfectants, American

e Abstract-Background and Objectives: This report provides an overview of advances in wound repair devised by our research team during the last four decades. This collective review is presented in two parts. Discussion: The following components are included in Part I: 1) search and treat life-threatening trauma; 2) conduct a thorough history; 3) examine the wound using aseptic technique; 4) anesthetize the wound before cleansing; 5) hair removal, skin disinfection, hemostasis, surgical debridement, and mechanical cleansing; 6) antibiotics, drains, and open wound management. Conclusion: On the basis of these comprehensive research studies, we have noted a marked reduction in the incidence of wound infection in traumatic wounds. © 2010 Elsevier Inc. e Keywords-trauma wound repair; life-threatening trauma; aseptic technique; local anesthesia; hair removal; antibiotics; open wound management

- by Curtis Tribble
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- Emergency Medicine, Wound Healing, Emergency Medical Services, Infection Control

Background: There is a lack of research studies on periurethral cleansing before catheterization among home care patients. The purpose of this study was to compare the risk of acquiring symptomatic urinary tract infections through the conventional practice of using 0.05% chlorhexidine gluconate (CHG) versus sterile water for periurethral cleansing before insertion of an indwelling urinary catheter. Methods: A randomized controlled trial was used, and subjects were randomly allocated to either the sterile water group or the 0.05% CHG group. Urine specimens for culture were collected 4 times for each subject within 2 weeks. Results: Seventy-four urine samples were collected in 20 subjects (sterile water group, 8; 0.05% CHG group, 12). There was no significant difference in colonization count between the 2 groups. In addition, none of the subjects in the 2 groups developed symptomatic bacteriuria. Conclusion: Using sterile water to clean the periurethral area before catheterization among home care patients will not increase the risk for urinary tract infections.

- by Kin Cheung Cheung
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- Nursing, Water, Hong Kong, Medicine

Grey water a b s t r a c t Adequate disinfection of grey water prior to reuse is important to prevent the potential transmission of disease-causing microorganisms. Chlorine is a widely utilised disinfectant and as such is a leading contender for disinfection of grey water intended for reuse. This study examined the impact of organics and particles on chlorine disinfection of grey water, measured by total coliform inactivation. The efficacy of disinfection was most closely linked with particle size. Larger particles shielded total coliforms from inactivation and disinfection efficacy decreased with increasing particle size. Blending to extract particleassociated coliforms (PACs) following chlorine disinfection revealed that up to 91% of total coliforms in chlorinated grey water were particle associated. The organic concentration of grey water affected chlorine demand but did not influence the disinfection resistance of total coliforms when a free chlorine residual was maintained. Implications for urban water reuse are discussed and it is recommended that greywater treatment systems target suspended solids removal to ensure removal of PACs prior to disinfection.

- by Bruce Jefferson
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- Microbiology, Water, Water Reuse, Multidisciplinary
- by Manju Sharma
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- Nursing, Bacteria, Disinfectants, Disinfection