Efficacy of Wound Cleansers on Wound-Specific Organisms Using In Vitro and Ex Vivo Biofilm Models

Biofilms are believed to be a source of chronic inflammation in non-healing wounds.

PURPOSE

In this study, the pre-clinical anti-biofilm efficacy of several wound cleansers was examined using the Calgary minimum biofilm eradication concentration (MBEC) and ex vivo porcine dermal explant (PDE) models on Pseudomonas aeruginosa, methicillin-resistant Staphylococcus aureus (MRSA), and Candida albicans biofilms.

METHODS

A surfactant-based cleanser and antimicrobial-based cleansers containing ionic silver, hypochlorous acid (HOCl), sodium hypochlorite (NaOCl), and polyhexamethylene biguanide (PHMB) were tested on the MBEC model biofilms with a 10-minute application time. Select cleansers were then tested on the mature PDE biofilms with 10-minute applications followed by the application of cleanser-soaked gauze. The PDE model was further expanded to include single and daily applications of the cleansers to mimic daily and 72-hour dressing changes.

RESULTS

In the MBEC model, PHMB- and HOCl-based cleansers reduced immature MRSA, C albicans, and P aeruginosa biofilm regrowth by > 3× when compared with silver, surfactant, and saline cleansers. The major differences could be elucidated in the PDE model in which, after daily application, 1 PHMB-based cleanser showed a statistically significant reduction (3-8 CFU/mL log reduction) in all mature biofilms tested, while a NaOCl-based cleanser showed significant reduction in 2 microorganisms (3-5 CFU/mL log reduction, P aeruginosa and MRSA).The other PHMB-based cleanser showed a statistically significant 3 log CFU/mL reduction in P aeruginosa. The remaining cleansers showed no statistically significant difference from the saline control.

CONCLUSION

Results confirm that there are model-dependent differences in the outcomes of these studies, suggesting the importance of model selection for product screening. The results indicate that 1 PHMB-based cleanser was effective in reducing mature P aeruginosa, MRSA, and C albicans biofilms and that sustained antimicrobial presence was necessary to reduce or eliminate these mature biofilms.

New approach for the removal of mature biofilms formed by wild strains of Listeria monocytogenes isolated from food contact surfaces in an Iberian pig processing plant

One of the main objectives of the food industry is to guarantee food safety by providing innocuous food products. Therefore, this sector must consider all the possible biotic or abiotic contamination routes from the entry of raw materials to the release of the final product. Currently, one important problem in this regard is the presence of biofilms on food contact surfaces which can transmit pathogens such as L. monocytogenes. In industrial conditions biofilms are found in a mature state, so it is essential that when carrying out removal effectiveness studies in vitro the tests are realized with models that produce these structures in a similarly mature state. The main objective of this study was to evaluate the effectiveness of an alternative treatment (i.e. enzymatic detergent that include natural antimicrobial agents) and a conventional treatment (i.e. chlorinated alkaline) for the elimination of mature L. monocytogenes biofilms. The results showed a cell detachment from the formed mature biofilms with an effectivity of between 74.75%-97.73% and 53.94%-94.02% for the enzymatic treatment and the chlorinated alkaline detergent, respectively. On a qualitative level, it was observed that the dispersion in the structure was much higher for the enzymatic treatment than for the chlorinated alkaline, which continued to show obvious structure integrity. All this leads to the conclusion that treatments with an enzymatic detergent have a significantly greater impact on the removal of mature L. monocytogenes biofilms, although a further disinfection process would be needed, enhancing even more the treatment effectivity. This may imply that the industrial approach to addressing this problem should be modified to include new perspectives that are more effective than traditional ones.

Chemical Pollution in Healing Spaces: The Decalogue of the Best Practices for Adequate Indoor Air Quality in Inpatient Rooms

Indoor air quality (IAQ) is one of the main topics in which governments are focusing. In healthcare facilities, several studies have reported data analysis and case studies to improve users' health. Nowadays, although many studies have been conducted related to the biological and physical risks, the chemical risks have been less investigated and only in some specific functional areas of the hospitals. Starting from some systematic reviews and research works, this paper aims to list the best healthy practices for an adequate IAQ in inpatient wards. In particular, the decalogue lists the strategies related to chemical pollution, starting from design and management, with a focus on (a) localization of hospitals and inpatient rooms, (b) hospital room, (c) microclimatic parameters, (d) ventilation systems, (e) materials and finishing, (f) furniture and equipment, (g) cleaning products and activities, (h) maintenance and (i) management activities, and (l) users and workers. The multidisciplinary approach emphasizes the need for interdisciplinary knowledge and skills aimed to find solutions able to protect users' health status. The design and management decision-making, ranging from the adequate choices of construction site and hospital exposure, finishing materials, cleaning and maintenance activities, etc., which can affect the IAQ must be carried out based on scientific research and data analysis.

Validation of leaf enzymes in the detergent and textile industries: launching of a new platform technology

Chemical catalysts are being replaced by biocatalysts in almost all industrial applications due to environmental concerns, thereby increasing their demand. Enzymes used in current industries are produced in microbial systems or plant seeds. We report here five newly launched leaf-enzyme products and their validation with 15 commercial microbial-enzyme products, for detergent or textile industries. Enzymes expressed in chloroplasts are functional at broad pH/temperature ranges as crude-leaf extracts, while most purified commercial enzymes showed significant loss at alkaline pH or higher temperature, required for broad range commercial applications. In contrast to commercial liquid enzymes requiring cold storage/transportation, chloroplast enzymes as a leaf powder can be stored up to 16 months at ambient temperature without loss of enzyme activity. Chloroplast-derived enzymes are stable in crude-leaf extracts without addition of protease inhibitors. Leaf lipase/mannanase crude extracts removed chocolate or mustard oil stains effectively at both low and high temperatures. Moreover, leaf lipase or mannanase crude-extracts removed stain more efficiently at 70 °C than commercial microbial enzymes (<10% activity). Endoglucanase and exoglucanase in crude leaf extracts removed dye efficiently from denim surface and depilled knitted fabric by removal of horizontal fibre strands. Due to an increased demand for enzymes in the food industry, marker-free lettuce plants expressing lipase or cellobiohydrolase were created for the first time and site-specific transgene integration/homoplasmy was confirmed by Southern blots. Thus, leaf-production platform offers a novel low-cost approach by the elimination of fermentation, purification, concentration, formulation and cold-chain storage/transportation. This is the first report of commercially launched protein products made in leaves and validated with current commercial products.

A risk-based, product-level approach for assuring aquatic environmental safety of cleaning products in the context of sustainability: The Environmental Safety Check (ESC) scheme of the A.I.S.E. Charter for Sustainable Cleaning

Cleaning products have long been a focus of efforts to improve sustainability and assure safety for the aquatic environment when disposed of after use. The latter is addressed at ingredient level through environmental risk assessment, including in formal frameworks such as REACH. Nevertheless, in the context of programs to improve overall sustainability, stakeholders demand both environmental safety assurance and progress at product level. Current product-level approaches for aquatic toxicity (e.g., USEtox™, Critical Dilution Volume) can be seen as predominantly hazard-based. The more logical approach would be risk-based, because ecotoxicity is generally threshold-dependent and hazard-based assessment produces conflicts with risk-based learnings. The development of a risk-based approach to assess formulated products is described: the International Association for Soaps, Detergents and Maintenance Products (A.I.S.E.) Charter Environmental Safety Check (ESC), which is consistent with the scientific principles underlying REACH. This is implemented through a simple spreadsheet tool and internal database of ingredient parameters including predicted no-effect concentration (PNEC) and removal rate. A novel feature is applying market volume information for both product types and ingredients to permit a risk-based calculation. To pass the ESC check, the projected environmental safety ratio (PESR) for each ingredient as formulated and dosed (unless cleared by a published risk assessment or exempted as inherently low risk) must be less than 1. The advantages of a risk-based approach are discussed. The strengths and limitations of various possible approaches to standard-setting, product-ranking and driving continuous improvement in respect of potential ecotoxic impacts on the aquatic environment are considered. It is proposed that as ecotoxicity is generally accepted to be threshold-dependent, with no effect below the threshold, the most constructive approach to continuous improvement of sustainability with regard to ecotoxicity is to focus efforts on instances where the safety margins for ingredients as used in specific products are narrow. This necessitates a risk-based approach. Integr Environ Assess Manag 2017;13:127-138. © 2016 The Authors. Integrated Environmental Assessment and Management published by Wiley Periodicals, Inc. on behalf of SETAC.

Hemodialysis Catheter Care: Identifying Best Cleansing Agents

In an attempt to create a standardized resource for cleansing both non-tunneled and tunneled hemodialysis catheters, it was discovered that all disinfectants are not compatible with all catheters. This article describes the process used to identify best practices for hemodialysis catheter care and steps taken to standardize practice throughout a hospital network. Standardized evidence-based practice preserves the integrity of catheters while allowing nurses to provide quality care to patients.

A recreational water quality index using chemical, physical and microbiological parameters

PURPOSE

The aim of this paper was to develop a new recreational water quality index (RWQI) as a tool to ensure the health of swimmers and to take practical decisions.

METHODS

RWQI was elaborated with epidemiological data, and we carried out an exhaustive study of the different guidelines for recreational waters proposed by different organisations around the world. Different parameters were chosen, considering, as a priority, the swimmer's contact and the possibility of ingestion of water during the recreational activity. Furthermore, rating curves were established for pH, chemical oxygen demand, nitrate, phosphate, detergents, enterococci, total coliforms, faecal coliforms and Escherichia coli.

RESULTS AND CONCLUSIONS

The index was applied to the data set on water quality of the Potrero de los Funes River (San Luis, Argentina), generated during 2 years (2009-2010). Following the RWQI values classification, most of the Potrero de los Funes water samples fell in the good quality range during the study period.

Newly cleaned physician uniforms and infrequently washed white coats have similar rates of bacterial contamination after an 8-hour workday: a randomized controlled trial

BACKGROUND

Governmental agencies in the United Kingdom and Scotland have recently instituted guidelines banning physicians' white coats and the wearing of long-sleeved garments to decrease nosocomial transmission of bacteria.

OBJECTIVE

Our aim was to compare the degree of bacterial and methicillin-resistant Staphylococcus aureus contamination of physicians' white coats with that of newly laundered, standardized short-sleeved uniforms after an 8-hour workday and to determine the rate at which bacterial contamination of the uniform ensued.

DESIGN

The design was a prospective, randomized controlled trial.

SETTING

The setting was a university-affiliated public safety-net hospital.

PARTICIPANTS

One hundred residents and hospitalists on an internal medicine service participated.

INTERVENTION

Subjects wore either a physician's white coat or a newly laundered short-sleeved uniform.

MEASUREMENTS

Bacterial colony count and the frequency with which methicillin-resistant Staphylococcus aureus was cultured from both garments over time were measured.

RESULTS

No statistically significant differences were found in bacterial or methicillin-resistant Staphylococcus aureus contamination of physicians' white coats compared with newly laundered short-sleeved uniforms or in contamination of the skin at the wrists of physicians wearing either garment. Colony counts of newly laundered uniforms were essentially zero, but after 3 hours of wear they were nearly 50% of those counted at 8 hours.

CONCLUSIONS

Bacterial contamination occurs within hours after donning newly laundered short-sleeved uniforms. After 8 hours of wear, no difference was observed in the degree of contamination of uniforms versus infrequently laundered white coats. Our data do not support discarding long-sleeved white coats for short-sleeved uniforms that are changed on a daily basis.

Assessment of disinfectants cleaning against bacterial biofilm of house hold water tanks

The purpose of this study was to compare the efficacy, in terms of bacterial biofilm penetration and killing, of some chemical disinfectants against E. coli and P. aeruginosa. This study was undertaken to examine the efficacy of some disinfectants including sodium hypochlorite, povidine and tryad detergent against E. coli biofilms and the efficacy of sodium hypochlorite and tryad detergents against P. aeruginosa. Two species biofilm of E. coli and P. aeruginosa were grown by flowing a dilute tryptic soy broth medium over an inclined cement, polyethylene, fiberglass and galvanized steel slides, 2.25 x 2.25 cm2 for 15 days. Biofilm formation was evaluated by scanning electron microscopy (SEM) and standard plate counts procedures through selective media for both E. coli and P. aeruginosa. In addition, some disinfectants were selected through disk diffusion susceptibility test. The disinfectants which gave higher zone of inhibitions, were applied to remove of E. coli and P. aeruginosa biofilms from cement, fiberglass, polyethylene and galvanized steel slide surfaces. Results showed that all disinfectants tested gave high inhibition of biofilm adhesion to tank surfaces with some being significant.

CONCLUSION

polyethylene and galvanized steel are strongly recommended as alternative drinking house holds water tanks in Saudi Arabia. The choice of disinfectants or cleaning agents along with optimum concentrations and the time of action is very important when destroying microbes. It is also important that resistance of microbes to some disinfectants and cleaning agents is take into consideration when planning the cleaning process.

Magnetic cleansing of weathered/tarry oiled feathers--the role of pre-conditioners

Iron powder has previously been demonstrated to be effective in the removal, via magnetic harvesting, of a wide variety of oil contaminants from feathers and plumage. This study investigates the efficacy of magnetic cleansing for the removal from feathers of tarry contamination that has been allowed to weather. Clusters of feathers from Mallard duck (Anas platyrhnchos) and Little Penguin (Eudyptula minor) were completely immersed in a tarry contaminant and allowed to weather from one to fourteen days. The contaminant was removed using a magnetic cleansing protocol and the removal efficacy assessed gravimetrically. For one, seven and fourteen days of weathering, a final removal (after fourteen treatments) of more than 99% and 97% was achieved for duck feathers and penguin feathers, respectively. Repeating the experiments (for a seven-day weathering period) for both duck and penguin feathers, with the judicious application of a pre-conditioner (olive oil), further improved removal efficacy. A convenient method to screen for improved pre-conditioning agents is suggested.

Study on OELs for enzyme-containing detergent in China

This study is aimed at setting occupational exposure levels for total detergent dust and enzymes in detergent industries. The study population consisted of 795 workers from four enzyme-containing detergent manufacturing plants (A1, A2, B1 and B2), and 156 control workers from an electronic assembly factory. Work environment monitoring was conducted using high volume of air sampler fro measuring the concentration of total dust (mg/m3), and analyzing the level of enzyme (ng/m3) by ELISA method. A standard questionnaires, pulmonary function test, and skin prick test are used to assess health effects. The levels of detergent total dust varied from 0.2 mg/m3 to 12.54 mg/m3. For enzyme levels, in A1, B1 and B2, the concentration ranged from non-detectable to 9.92 ng/m3 and in A2, the concentration was analyzed by enzyme activity methods and was expressed as Gu/m3 (1 Gu/m3 = 16 ng/m3). The concentration is between 0.16-31.36 ng/m3. Non-specific irritation rates in exposed workers were significantly higher than that in controls. Based on the data collected from A1, B1 and control plants, 95% benchmark dose lower bound were calculated as 1.17 mg/m3. The difference of pulmonary function between exposed workers and controls is not significant. The results of SPT showed that neither Savinase- nor Alcalase-induced sensitization was found in controls. The prevalence rates of sensitization for Savinase and Alcalase were ranged between 3.2% and 31% in all enzyme-containing detergent manufacturers investigated. No case of occupational asthma was observed. For total dust, 1 mg/m3 is suggested as permissible concentration-time weighted average (PC-TWA), and 2 mg/m3 as permissible concentration-short term exposure limit (PC-STEL). For the enzyme Subtilisins, 15 ng/m3 is suggested as PC-TWA, and 30 ng/m3 as PC-STEL.

Mycobactericidal and tuberculocidal activity of Korsolex AF, an amine detergent/disinfectant product

The mycobactericidal and tuberculocidal activities of Korsolex AF against Mycobacterium tuberculosis, Mycobacterium avium-Mycobacterium intracellulare (MAI), Mycobacterium kansasii and Mycobacterium chelonae were determined using quantitative suspension and carrier tests. The effects of organic load and hard water were also considered. A clinical isolate of MAI was the most resistant of the four test organisms. A 2% solution had good mycobactericidal and tuberculocidal activities after 30 min of exposure. Although further evaluation using European standard tests is necessary, we conclude that Korsolex AF appears to be a promising product for the disinfection of hospital instruments contaminated with mycobacteria.

Comparison of the effect of detergent versus hypochlorite cleaning on environmental contamination and incidence of Clostridium difficile infection

To determine how best to decontaminate the hospital environment of Clostridium difficile, we carried out a cross-over study on two elderly medicine wards to determine whether cleaning with a hypochlorite disinfectant was better than using neutral detergent in reducing the incidence of C. difficile infection (CDI). We examined 1128 environmental samples in two years, 35% of which grew C. difficile. There was a significant decrease of CDI incidence on ward X, from 8.9 to 5.3 cases per 100 admissions (P<0.05) using hypochlorite, but there was no significant effect on ward Y. On ward X the incidence of CDI was significantly associated with the proportion of culture-positive environmental sites (P<0.05). On ward Y the only significant correlation between CDI and C. difficile culture-positive environmental sites was in patient side-rooms (r=0.41, P<0.05). The total daily defined doses of cefotaxime, cephradine and aminopenicillins were similar throughout the trial. These results provide some evidence that use of hypochlorite for environmental cleaning may significantly reduce incidence of CDI, but emphasize the potential for confounding factors.

Skin cleansing in neonates and infants--basics of cleansers

OBJECTIVE

Using a proper cleanser for bathing neonatal and infant skin is of prime importance considering the anatomical differences with regard to adult skin. Choosing the right cleanser requires knowledge of the composition of a cleanser as well as the properties of the individual ingredients.

METHODS

The article discusses the guidelines for cleansing the skin of neonates and infants. The characteristics of an ideal cleanser for pediatric skin have also been enumerated.

RESULTS

In India, majority of cleansers recommended for babies do not mention their active ingredients. Their claims of "mildness" have not been substantiated with clinical studies. Cetaphil, a non-soap, lipid-free liquid cleanser, has been clinically proven to be non-irritating by the Chamber Scarification Test. Moreover, Cetaphil also has a pH of less than 7, which does not alter the physiological pH of skin.

CONCLUSION

Hence, Cetaphil should definitely be considered while choosing a cleanser for neonates and infants.

"Visually clean" as a sole acceptance criterion for cleaning validation protocols

The role of visual examination as the sole acceptance criterion in cleaning validation protocols is explored, including the proper definition of "visual limit" for a given residue. Such a visual limit is specific to the surface the residue is on, and is further defined by viewing conditions, such as lighting, distance, and angle of viewing. A visually clean standard may only be properly utilized if the visual limit is below any scientifically calculated residue limit, such as that determined by a traditional dose-based limit determination. While such an approach, properly applied, has scientific justification and appears to be accepted by the proposed Annex 15 to the European GMPs, the approach is still untested with regulatory authorities.

Effectiveness of hand-cleansing agents for removing methicillin-resistant Staphylococcus aureus from contaminated hands

OBJECTIVE

The effectiveness of hand-cleansing agents in removing a hospital strain of methicillin-resistant Staphylococcus aureus from artificially contaminated hands of five volunteers was studied.

DESIGN

The products used were plain liquid soap, ethyl alcohol 70% (by weight), 10% povidone-iodine liquid soap (PVP-I), and chlorhexidine gluconate (4%) detergent. The experiments were performed using a Latin square statistical design, with two 5x4 randomized blocks. The removal rates of S aureus cells from contaminated fingertips were estimated by analysis of variance, the response variable being the log10 reduction factor (RF), ie, log10 of the initial counts minus log10 of the final counts. In the first and second blocks, the fingertips of the volunteers were contaminated in mean with 3.76 log10 colony-forming units ([CFU] light-contamination hand) and 6.82 log10 CFU (heavy-contamination hand), respectively.

RESULTS

In the first block, there were significant differences between treatments (P<.05). The 10% PVP-I (RF, 3.76) and 70% ethyl alcohol (RF, 3.51) had significantly higher removal rates than plain liquid soap (RF, 1.96) and 4% chlorhexidine (RF, 1.91). In the second block, 10% PVP-I (RF, 4.39) and 70% ethyl alcohol (RF, 3.27) also were significantly more effective than plain liquid soap (RF, 1.77) and 4% chlorhexidine (RF, 1.37; P<.05). Plain liquid soap was significantly more effective than chlorhexidine (4%) detergent.

CONCLUSIONS

The results suggest that 10% PVP-I and 70% ethyl alcohol may be the most effective hand-cleansing agents for removing methicillin-resistant S aureus strain from either lightly or heavily contaminated hands.

Use of quantitative microbial risk assessment for evaluation of the benefits of laundry sanitation

The goal of this study was to evaluate the risk assessment process for quantifying the contribution of contamination in the home to microbial infections. Whereas risks of enteric pathogens spread through food has been assessed, the spread of fecal-oral pathogens through surfaces likely at low rates would be difficult to address through epidemiologic studies. An alternative is quantitative risk assessment. The 4-step process of hazard identification, dose-response, exposure assessment, and risk characterization can be used; however, exposure assessment may follow a complicated pathway consisting of survival and transference. Microbial hazards in the home have focused primarily on enteric bacteria. Dose-response data are available; however, the transfer from the hands to the dose is uncertain. Through day care studies, Shigella has been shown to be transferred in this manner, and a dose-response model is available. By using these data and information on the transference of bacteria between clothing and hands, risk estimates were made for contaminated laundry. Risks were calculated as high as 10 per million population to much lower levels associated with lower excretion rates of the bacteria in the feces. Approximately a 90% and 99% reduction in the probability of disease through laundering and use of a sanitizing detergent, respectively, were suggested by the models. Better data are needed on incidence of disease in the population, excretion rates over the course of an infection, amount of feces spread in the home, distribution of bacteria, survival, and the transfer of the bacteria from surfaces to the hands and to the mouth.

The cleaning of polymer colloids

The current state of knowledge of the cleaning of polymer colloids is reviewed with regard to a wide range of cleaning and characterisation techniques. The type, level and quantity of impurities involved with different polymer latex formulations varies widely. Even for similar formulations, differences in the nature and number of functional groups reported are often a consequence of sometimes subtle differences in the cleaning procedures employed. Not only may surface functionality be affected but also monomer and oligomer extraction procedures may lead to morphological changes in the particles. No single technique alone is likely to be able to remove all impurities. Care is needed to avoid the introduction of new impurities from the equipment, materials and water used as well as possible contamination from atmospheric carbon dioxide, bacteria and fungi. These factors also need to be considered in the storage of latex particle standards.

Disinfection of food production areas

Disinfection, other than by heat, is ineffective unless all surfaces have previously been thoroughly cleaned to remove interfering materials. Cleaning is therefore extremely important as part of a two-stage cleaning and disinfection (sanitation) programme. The author describes the principles of sanitation, the chemicals and equipment involved, and the programme of events to be followed. For food products of 'low risk' (in terms of stable shelf life and safety), traditional sanitation programmes are adequate and in some cases disinfection may not be required. However, disinfection is essential for 'high-risk' food products, but this cannot be effectively undertaken without due consideration of hygienic design and possible cross-contamination. To ensure continued satisfactory performance of a sanitation programme, routine assessments should be undertaken.

Comparative evaluation of five surgical hand scrub preparations

Surgical hand scrubs should remove microorganisms from health care professionals' hands and forearms and maintain the lowest possible microbial counts during surgical procedures. This study evaluated the immediate, persistent, and residual efficacy of five surgical hand scrub products. The two chlorhexidine gluconate (CHG) products achieved significant immediate reduction in the microorganism count and demonstrated persistent and residual efficacy. The iodophor product exhibited effective immediate and persistent antimicrobial properties but failed to show significant residual effects. The parachlorometaxylenol products demonstrated low levels of immediate and persistent effects and no residual antimicrobial effects. The alcohol product demonstrated low immediate, persistent, and residual effects. The investigator concludes that CHG products are the most favorable surgical hand scrub preparations.

[Cleansing effect of two micromotor-driven endodontic handpieces.II. Effect of various rinsing solutions on the cleansing effect of the handpieces]

The cleansing effectivity of citric acid solution was significantly better than that of Neomagnol both with respect to the removal of the Smear Layer (SL) and to the number of visible dentinal tubular orifices, however a complete elimination of the SL could not be obtained. Neomagnol seemed to be more effective in the removal of superficial debris and tissue-remnants.

DNA profiling of bloodstains on linen pretreated with remedies used for cleaning and maintaining clothes

Linen was pretreated with 20 remedies for cleaning and maintaining clothes and 20 microliters blood was applied on each sample and dried. Restriction enzyme digest of bloodstain DNA was irregularly inhibited by highly concentrated residues of 2 detergents and a stain-remover and colour-brightener. An additional dialysis step to purify DNA (Gill 1987) reliably prevented disturbance. High molecular DNA was obtained in every case and bandshifts were not observed.

[Hygienic significance of surface-active substances in the conditions of soil contamination with chemical substances]

Urgent problems of the interaction of surface-active substances (SAS) with other ingredients under the conditions of chemical soil pollution are discussed, in particular, under the conditions of irrigation of agricultural fields with treated municipal sewage containing detergents. Before the beginning of the irrigation season the content of anion SAS in the arable layer of the soil is 2.02-2.66 mg/kg. In the middle of the vegetation period the quantity of detergents is increased 3-4 times fold. The authors suppose, that SAS may influence translocation of heavy metals from soil into plants. However, this question should be studied more carefully in the conditions of field experience with various SAS concentrations in soil.

Guideline for use of topical antimicrobial agents

This Guideline is based on published data available at the time of writing. The ideal means for comparing performance of various antimicrobial agents is through the conduct of carefully designed, large-scale clinical trials. Recommendations contained in this Guideline are subject to modification as additional data become available. It particularly should be noted that the implementation of universal precautions or body substance isolation has resulted in marked increase in the use of gloves for direct patient contact. Whether there is an additional cost-benefit rationale for handwashing with an antimicrobial agent remains to be studied.

Nosocomial infections on nursing units with floors cleaned with a disinfectant compared with detergent

Nosocomial infections on eight acute care nursing units in a tertiary care hospital was compared between two 3-month periods in which floors were cleaned with either disinfectant or detergent. Personnel performing infection surveillance were unaware of the cleaning product used. Surface cultures from selected floor sites were obtained at 3 and 6 months to assess microbial contamination. The combined nosocomial infection rate for the eight wards did not differ between disinfectant (8.0/100 patient discharges) and detergent (7.1/100). For individual wards, a significant difference in nosocomial infection rate between the two periods was observed in only one ward, favouring the detergent. No differences in floor contamination were observed.

A placebo-controlled trial of the effect of two preoperative baths or showers with chlorhexidine detergent on postoperative wound infection rates

The effect of preoperative whole-body washing with chlorhexidine detergent on the incidence of postoperative wound infection was assessed in a placebo-controlled trial of 1989 patients. Patients bathed or showered with chlorhexidine, placebo, or conventional bar soap, on two occasions in the 24 h before operation. The overall infection rate for patients treated with chlorhexidine was 9%, against 12.8% in the bar soap and 11.7% in the placebo groups; in the 'clean' surgery group infections were 7.2% against 10.2% and 10%, respectively. The Staphylococcus aureus infection rate in the 'clean' group was 3% for chlorhexidine against 6% for bar soap.

Detergents and detergency

A simple definition of a "clean" surface is one which is "free from any residual film or soil which is visible or can be felt by touch", ie it should not contaminate food or other consumable items with odour, microbial spoilage or chemical residue.

Strategies toward maximum detergent efficiency

Detergent Z demonstrated the most reliable cleaning and detergent delivery system. After the initial detergent evaluation, the data were compared against all detergents. It was found that acceptably cleaned items ranged from 37% to 85% per evaluation. Labor and material costs could be reduced greatly with the use of detergent Z, which had the best cleaning results. We also observed the advantage of a sensor in the detergent delivery system which can override some less obvious equipment malfunctions. Since detergent Z also exhibited the least amount of residue build-up, a savings in maintenance costs could be expected later on. The vendor of detergent Z showed great interest and concern for our department's needs and quality assurance by offering us numerous technical resources during the evaluation. One year following our detergent studies, detergent Z and its related line of cleaning products are being utilized in our hospital. We found that the four months spent analyzing detergents used in our utensil washers provided an interesting resource project that has been a positive investment in improved operations for the decontamination area. In Central Service alone, 61.7 hours a week were saved by the change in products. Quality of cleaning continues to be high. The practice of a weekly acid bath for the utensil washers has been discontinued; the acid bath will now be given when necessary, and has not been done since detergent Z was put into use six months ago. During the next fiscal year, savings of detergent, utilities and labor are conservatively projected at $30,000.