Removal of bovine digital dermatitis-associated treponemes from hoof knives after foot-trimming: a disinfection field study.

BACKGROUND: Bovine digital dermatitis (BDD) is an infectious foot disease found commonly in dairy herds. Foot-trimming is an important husbandry procedure for reducing the ensuing lameness; however, epidemiological, and microbiological studies have identified this as a risk activity for transmitting BDD. Three disinfectants have previously been identified in laboratory work as effective for removing viable BDD-associated Treponema spp., from hoof knife blades. The present study enrolled 133 dairy cattle with BDD lesions, and swabbed hoof knife blades before and after foot-trimming, and after knife disinfection with one of three disinfectants (1:100 FAM30®, 2% Virkon® and 2% sodium hypochlorite) to assess their efficacy under field conditions. RESULTS: Detection of BDD treponeme phylogroup DNA was undertaken by direct PCR of swabs, and viable treponemes were detected by PCR of swab cultures after 6 weeks' incubation. Where hoof knives did not contact the lesion, BDD-associated treponemes were detected after foot-trimming in 12/22 (54.5%) cases by direct PCR and 1/22 (4.5%) cases by PCR of cultured organisms. Where contact was made with the lesion, 111/111 (100%) samples taken after trimming were positive by direct PCR and 47/118 (39.8%) were positive by culture PCR. Viable organisms were identified in cultures from lesion stages M2, M3, M4 and M4.1. No viable organisms were detected after disinfection of hoof knives. CONCLUSIONS: Hoof knives post-trimming were frequently contaminated with BDD-associated treponeme DNA. Viable organisms were identified in cultures whether contact had been made between hoof knife and lesion or not, although contact clearly increased the frequency of detection of viable organisms. The three disinfectants tested were effective for removing viable organisms. The disinfection protocol used in this study should therefore be considered reliable for adoption as standard industry practice.

Measures to prevent goggles from fogging during the treatment of Coronavirus Disease 2019.

During these challenging and unprecedented times for the global communities as they battle the COVID-19 pandemic, we found a simple and effective way to prevent the goggles fogging. We hope that it will help the healthcare professionals who are still troubled by the problem of fogging goggles.

Incise Draping Reduces the Rate of Contamination of the Surgical Site During Hip Surgery: A Prospective, Randomized Trial.

BACKGROUND: Iodophor-impregnated adhesive incise drapes are widely used during surgeries for reducing surgical site contamination. There is little evidence to support the latter belief. This study evaluated the efficacy of iodophor-impregnated adhesive drapes for reducing bacterial contamination and counts at the incision site during hip surgery. METHODS: In this prospective, randomized clinical trial, we enrolled 101 patients undergoing open joint preservation procedure of the hip. Half the patients had the adhesive drape applied to the skin prior to incision, while the remainder underwent the same surgery without a drape. Culture swabs were taken from the surgical site at 5 points (preskin preparation, after skin preparation, postincision, before subcutaneous closure, prior to dressing application) and sent for culture and colony counts. Mixed-effects logistic regressions were used to estimate effects of time and drape application on contamination rate. RESULTS: At the conclusion of surgery, 12.0% of incisions with adhesive drapes and 27.4% without adhesive drapes were positive for bacterial colonization. When controlling for preoperative colonization and other factors, patients without adhesive drapes were significantly more likely to have bacteria present at the time of skin closure, and at all time points when swab cultures were taken. CONCLUSION: It appears that the iodophor-impregnated adhesive draping significantly reduces bacterial colonization of the incision. Bacterial count at the skin was extremely high in some patients in whom adhesive drapes were not used, raising the possibility that a subsequent surgical site infection or periprosthetic joint infection could arise had an implant been utilized.

Topical iodophor preparations: chemistry, microbiology, and clinical utility.

Iodophor preparations are commonly used in all medical specialties for antisepsis of the skin prior to injections, invasive procedures, and surgery. Povidone-iodine has some very intriguing properties that make it extremely effective as a broad spectrum bacteriocidal agent with no known bacterial resistance, potentially lending itself to broader applications than its current uses. In this article the background, formulations, chemistry, and microbiology of iodine will be reviewed and recent clinical investigations of utility beyond skin antisepsis will be discussed.

Critical role of water diffusion into matrix in external use iodine preparations.

Iodine preparations for external use are recommended for treating pressure ulcers with manifestations of infection and necrosis. These ulcers abundantly produce wound exudates, which could be absorbed by water-soluble base. In this study we aimed to improve the previously reported methodologies for water absorption and new methodologies were developed in Franz diffusion cell with 100kDa molecular weight cut-off (MWCO) membranes. Using these new methodologies water absorbing capacities of existing iodine preparations [povidone-iodine (PI) sugar ointment, iodine-potassium iodide (IKI) gel, cadexomer-iodine (CI) ointment] and another superabsorbent polymer dextranomer paste were evaluated. Water absorption indexes were 7.52, 1.98, 1.44 and 2.90(mg/cm(2)/min(0.5)), respectively. With PI sugar ointment observed amount of water absorbed increased in a linear fashion over time. In contrast, with IKI gel, CI ointment and dextranomer paste observed amount of water absorbed decreased over time. When the observed amount of water absorbed was plotted against square of time, the lines of IKI gel and CI ointment became linear. With dextranomer paste the line became biphasic with 1-folding point. These results suggest that water diffusion into matrix is the rate limiting step in IKI gel, CI ointment and dextranomer paste, and that capacity of absorbing wound exudates could substantially differ among these ointments.

Critical evaluation of cadexomer-iodine ointment and povidone-iodine sugar ointment.

Topical iodine forms are used for infected and necrotic pressure ulcers. Despite antimicrobial advantages several potential disadvantages were observed with controversial results. To clarify the controversy, the reactivity of povidone-iodine (PI) sugar ointment and cadexomer-iodine (CI) ointment toward biological components was investigated. L-Tyrosine as a component of proteins and egg lecithin as a component of lipid membranes were reacted with forms of iodine. Furthermore, water absorption abilities of ointments were investigated. The reactions of PI sugar ointment and CI ointment with L-tyrosine were reversely dependent on iodine concentrations. CI ointment reacted with lecithin in an iodine concentration dependent manner, while PI sugar ointment reacted with lecithin in an iodine concentration independent steady manner. However, at the clinically relevant iodine concentration (0.1, w/v%) PI sugar ointment reacted efficiently with L-tyrosine and less efficiently with lecithin, while CI ointment reacted efficiently with lecithin and less efficiently with L-tyrosine. Water absorption rate constant was 29.9 mg/cm(2)/min(0.5) for PI sugar ointment and 15.3 for CI ointment. Water absorption capacity per weight over 24 h was 26% forPI sugar ointment and 76% for CI ointment [corrected]. These results suggest that PI sugar ointment and CI ointment have different characteristics for iodine reactivity and water absorption.

Disinfectants' effect on mercury release from amalgam.

BACKGROUND: Mercury environmental discharge is under increased scrutiny by the U.S. Environmental Protection Agency (EPA). Dental amalgam should be processed properly to prevent an additional environmental burden. Some processing agencies require that submitted amalgam be noninfectious. Investigations have demonstrated that oxidizing disinfectants mobilize mercury from amalgam into solution and add mercury to the environmental burden if it is disposed of improperly. The authors conducted a study to evaluate the effect of representative disinfectants on amalgam mercury release. METHODS: The authors sized a high-copper spherical amalgam alloy to match that typically found in dental unit suction traps. They exposed 20 grams of the alloy to several disinfectant solutions and evaluated the filtered supernatant solution for mercury content. RESULTS: Chlorine disinfectant materials discharged the most mercury ions, followed by bromide, iodophor, peroxide/peracetic acid and phenolic disinfectants. The quaternary ammonium compound did not discharge mercury ions above the detection limit (0.2 parts per billion) into solution. CONCLUSIONS: A quaternary ammonium compound did not mobilize mercury ions into solution when used as a disinfectant agent for amalgam. Chlorine disinfectants mobilized mercury ions the most, followed by bromide, iodophor, peroxide/peracetic acid and phenolic disinfectants. CLINICAL IMPLICATIONS: Dentists are obligated to be good environmental stewards and should follow practices that reduce environmental mercury release. Dental personnel should be aware that oxidizing disinfectants mobilize mercury ions into solution, which will be added to the environment if they are processed improperly. If required by processing, dental personnel should consider the different oxidizing effects of commonly used disinfectants.

Pharmaceutical and bacteriological study on povidone-iodine sugar ointment.

Povidone-iodine sugar ointment is an excellent preparation for the treatment of decubitus. It has been used as an intrahospital preparation made according to the formula each hospital decided on from experience. Although commercial products have also been developed and used, they are too expensive. The efficacy of a povidone-iodine sugar ointment formulation which can be prepared by a single method and which has the stability and antibacterial activity equal to commercially available products was evaluated. As the test drugs, one commercially available product (UP), and three preparations with different formulas (P-1, P-2 and P-3) were used. All of these test drugs were stored at 20 and 40 degrees C. Specimens were sampled immediately after storage and after 20, 60, 90, 120 and 150 days and examined pharmaceutically (measurement of pH value and determinations of available iodine and sucrose levels). For the determination of bacteriological effects, 5 standard strains of 5 genera and 5 strains of methicillin-resistant Staphylococcus aureus (MRSA) were used and the time required to kill the bacteria was determined. For UP and P-3, no changes were seen pharmaceutically after 150 days of storage at 20 and 40 degrees C. However, MRSA could not be killed within 30 min. P-1 and P-2 showed remarkable changes pharmaceutically after 60 days of storage at 40 degrees C and could not be used any more. It became possible to make a preparation of povidone-iodine sugar ointment which has a stability almost similar to that of UP. Moreover, such a preparation can be made at low cost. However, since the bactericidal activity against MRSA was not higher than those of other drugs, the future task is to improve the bactericidal activity.

Effect of disinfection of custom tray materials on adhesive properties of several impression material systems.

The effects of impression tray disinfection procedures on the bond strength of impression-material adhesives to two types of resin trays were evaluated with a tensile test. Autopolymerizing acrylic resin and a visible light-curing resin were formed into one-half inch cubes. A screw eye was attached to each cube before polymerization. Perforated trays were fabricated with stops to maintain an even one-eighth inch of impression material over the resin block. Hooks on the opposite side permitted attachment of the metal plate to a mechanical testing machine. Before adhesive was applied, one third of the resin specimens were immersed in a 1:213 iodophor solution; one third in a 10% sodium hypochlorite solution, and one third were kept in the "as fabricated" condition. Polysulfide, polyether, and polyvinyl siloxane impression material-adhesive systems were evaluated. The resin-impression material-metal plate couples were attached to a mechanical testing machine and tensile forces were applied at a separation rate of 5 inches per minute. Mean values for adhesive strength ranged from 3.49 kg/cm2 for the autopolymerizing acrylic resin/iodophor/polyether combination to 10.55 kg/cm2 for the autopolymerizing acrylic resin/untreated/polyvinyl siloxane combination. Differences were detected among materials and disinfecting procedure. Clinically, disinfection of resin trays may adversely affect retention of the impression material to the tray.

Immersion disinfection of irreversible hydrocolloid impressions. Part 2: Effects on gypsum casts.

This study evaluated the quality of gypsum casts recovered from disinfected irreversible hydrocolloid impressions. Four disinfectants were evaluated: 0.525% sodium hypochlorite, Alcide LD, Iodofive, and OMC II. Water served as the control. Specimens were evaluated for roughness, surface detail, and dimensional stability. Impressions disinfected with NaOCI or Alcide produced gypsum casts with physical properties that were generally equal or superior to casts from impressions rinsed with water. OMC II and Iodofive generally produced casts inferior to the controls.

Effects of disinfecting irreversible hydrocolloid impressions on the resultant gypsum casts: Part III--Dimensional changes.

This study evaluated the effect of disinfection time (10, 30 and 60 minutes) on the dimensional changes of stone casts poured against an irreversible hydrocolloid impression material (Jeltrate). Impressions were made of a stainless steel analog of a maxillary arch. The impressions were sprayed with bleach, iodophor, phenol, and water and were stored for designated times before poured in a type IV stone (Vel-mix). The arch width, length, and depth of the vault of the resultant casts were measured by use of a contact measuring device (MicroVal) capable of measuring to 0.0001 mm. Data were analyzed with two-way analysis of variance at the 95% confidence level. Results indicated that disinfection treatment of alginate impressions with surface disinfectants did not cause significant dimensional changes in the resultant stone casts from statistical and clinical points of view.

Effects of disinfecting irreversible hydrocolloid impressions on the resultant gypsum casts: Part I--Surface quality.

This study evaluated the effects of disinfection time (10, 30, and 60 minutes) on the surface quality of stone casts poured against an alginate impression material (Jeltrate). Five antimicrobial agents were tested: Sporicidin spray, sodium hypochlorite, and iodophor for spray; and Sporicidin cold sterilization solution and Cidexplus glutaraldehyde solution for immersion. Impressions, flushed with water and stored for 0, 10, 30, and 60 minutes before pouring, served as untreated controls. On completion of the disinfection treatments, the impressions were rinsed and poured in Velmix stone. The effects on cast surface were evaluated under a stereomicroscope by three experienced raters. A 1-to-4 scoring system was developed to rate the surface quality in terms of smoothness and detail reproduction. Both immersion disinfectants proved to be unacceptable for treating alginate impressions. The mean scores of other disinfectant-time combinations were compared with the use of the Tukey-Kramer method with a 95% confidence interval. The results indicated that treatment time had statistically significant effects on the quality of cast surface in Sporicidin spray, sodium hypochlorite, and untreated control groups but not in the iodophor spray group.

An evaluation of dental stones after repeated exposure to spray disinfectants. Part I: Abrasion and compressive strength.

This study investigated the effect of repeated applications of spray disinfectants on gypsum surfaces. Types III and IV gypsum products were evaluated in combination with iodophor, acid glutaraldehyde, phenol, and water spray. Results demonstrated greater resistance to abrasion with increasing numbers of water or disinfectant spray applications. Acid glutaraldehyde spray decreased the compressive strength of type III stone by 26%, phenol increased the compressive strength of type IV stone by 18%, and iodophor had no significant effect on either stone relative to compressive strength.