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Sixty-three cows were used in a natural exposure trial for 1 yr to determine the effects of a 1.94% linear dodecyl benzene sulfonic acid and a 1% iodophor teat dip on teat canal and intramammary infections. Overall, total teat canal infections increased 28.9% and total intramammary infections increased 30% in quarters dipped with the linear dodecyl benzene sulfonic acid compared with a 14.3% increase in teat canal infections and a 17.4% decrease in intramammary infections for the iodophor group. Higher frequencies were observed for teat canal and intramammary infections caused by Staphylococcus epidermidis in the linear dodecyl benzene sulfonic acid group. Stephylococcus hyicus was the predominant organism isolated from teat canal and intramammary infections in the iodophor group. No difference was observed between the two teat dips in the persistence of Staphylococcus aureus canal infections. A greater number of S. hyicus canal infections persisted in the iodophor group, whereas teat canal infections produced by S. epidermidis and Staphylococcus xylosus persisted longer in the sulfonic acid group. Results of this study indicated that use of a linear dodecyl benzene sulfonic acid teat dip for 1 yr was not associated with increased S. aureus teat canal infections and intramammary infections. However, linear dodecyl benzene sulfonic acid appeared to affect the distribution of coagulase-negative staphylococci isolated from teat canal infections and intramammary infections.

The activities of 10 formulations as mycobactericidal agents in Mycobacterium tuberculosis-contaminated suspensions (suspension test) and stainless steel surfaces (carrier test) were investigated with sputum as the organic load. The quaternary ammonium compound, chlorhexidine gluconate, and an iodophor were ineffective in all tests. Ethanol (70%) was effective against M. tuberculosis only in suspension in the absence of sputum. Povidone-iodine was not as efficacious when the test organism was dried on a surface as it was in suspension, and its activity was further reduced in the presence of sputum. Sodium hypochlorite required a higher concentration of available chlorine to achieve an effective level of disinfection than did sodium dichloroisocyanurate. Phenol (5%) was effective under all test conditions, producing at least a 4-log10 reduction in CFU. The undiluted glutaraldehyde-phenate solution was effective against M. tuberculosis and a second test organism, Mycobacterium smegmatis, even in the presence of dried sputum, whereas the diluted solution (1:16) was only effective against M. smegmatis in the suspension test. A solution of 2% glutaraldehyde was effective against M. tuberculosis. This investigation presents tuberculocidal efficacy data generated by methods simulating actual practices of routine disinfection.

The virucidal efficacy of germicides acting on an irreversible hydrocolloid surface is not known. Tests that are currently performed on germicides do not simulate the conditions under which the germicides are often used. One major concern for the dental profession is the disinfection of dental impressions, particularly irreversible hydrocolloid impressions. This study was designed to test the biocidal action of germicides against an enveloped virus on an irreversible hydrocolloid surface. The disinfection model, which was developed to simulate clinical conditions, specified the use of vesicular stomatitus virus, an animal virus amenable to safe handling. A 0.5% sodium hypochlorite spray inactivated the virus when the spray was allowed to remain on the impression 3 to 10 minutes. The iodophor disinfectant required a 3- to 10-minute immersion for total inactivation. Although 2% glutaraldehyde achieved total viral inactivation in less than 1 minute, the authors conclude that short disinfectant sprays, in general, are not an appropriate disinfection method.

Effects of a .18% iodophor teat dip and a fatty acid plus lactic acid teat dip on teat canal infections were studied in two separate trials under experimental challenge procedures using Staphylococcus aureus and Streptococcus agalactiae. The iodophor teat dip was 90% effective in preventing new S. aureus teat canal infections and 95.6% effective in reducing progression of S. aureus teat canal infections to intramammary infections. The dip also reduced persistence of S. aureus teat canal colonizations from week to week by 94.4%. The fatty acid plus lactic acid dip had no effect on preventing S. aureus teat canal infections but reduced progression of S. aureus teat canal infections to intramammary infections by 43.8%. The fatty acid plus lactic acid dip also reduced the persistence of S. aureus teat canal infections by 39%. An insufficient number of Strep. agalactiae teat canal infections was detected in both trials for valid analyses. Neither dip had any effect on prevalence of naturally occurring, coagulase-negative staphylococcal teat canal infections or on teat canal infections by other organisms.

The efficacy of 14 disinfectants against Listeria innocua and two strains of Listeria monocytogenes in the presence of organic matter was studied. Quantitative efficacy tests were used. Many of the disinfectants tested were not as effective on Listeria spp. when the test organisms were dried onto the surface of steel disks (carrier tests) as they were when the organisms were placed in suspension (suspension test). The presence of whole serum and milk (2% fat) further reduced the disinfectant capacities of most of the formulations studied. Only three disinfectants (povidone-iodine, chlorhexidine gluconate, and glutaraldehyde) were effective in the carrier test in the presence of serum; however, all three were ineffective when challenged with milk (2% fat). Only one solution, sodium dichloroisocyanurate, was effective in the presence of milk. All but four formulations (chloramine-T, phosphoric acid, an iodophor, and formaldehyde) were effective in the suspension tests, regardless of the organic load. L. monocytogenes was observed to be slightly more resistant to disinfection than L. innocua was. There was no difference in disinfectant susceptibility between the two strains of L. monocytogenes. These findings emphasize the need for caution in selecting an appropriate disinfectant for use on contaminated surfaces, particularly in the presence of organic material.

We investigated the effect of disinfectants on microbial contamination present on the interior surface of polyvinyl chloride (PVC) pipes filled with 600 ml of water contaminated with Pseudomonas pickettii and P. aeruginosa. After eight weeks, water was removed, and the test pipes exposed to various types of aqueous disinfectants. Disinfectant samples were removed, neutralized, and examined for recovery of microorganisms by membrane filtration. After seven-days exposure, disinfectant solutions were removed and pipes filled with sterile distilled water. Water was examined by membrane filtration at seven-day intervals to determine whether the organisms had survived in the pipes. Colonization of PVC surfaces were examined during each study phase by scanning electron-microscopy (SEM). P. aeruginosa was isolated directly from iodophor disinfectant, phenolic germicide, and iodophor antiseptic solutions. After addition of sterile water, P. aeruginosa was recovered from PVC pipes previously exposed to chlorine, phenolic, quaternary-ammonium, and iodophor disinfectants; P. pickettii was recovered from water in pipes treated with iodophor disinfectant, chlorine, and ethanol. The existence of glycocalyx-like cellular masses on the interior wall of PVC pipes most likely protected embedded organisms from the microbicidal action of some of the disinfectants tested and served as the reservoir for continuous contamination.

BACKGROUND: Post-cataract endophthalmitis is rare (

Our objective was to develop a rapid and safe liver biopsy technique that could be repeated on multiple occasions in individual neonatal calves. A pilot study was performed to verify the efficacy of sedation and restraint procedures and to evaluate different biopsy instruments. Following the pilot experiment, a biopsy trocar was fabricated and an experiment was conducted using this procedure. Liver biopsies were performed in neonatal calves on d 4, 9, 15, 21, and 28 of life to evaluate the effect of vitamin A intake on liver vitamin A concentrations. On these days, a single injection of ceftiofur sodium was administered i.m. 1 to 2 h prior to the procedure. Calves were lightly sedated with xylazine and placed on a surgical table in left-lateral recumbency. The right caudo-thoracic area was clipped and scrubbed with an iodophor agent. Following administration of a local anesthetic (lidocaine), a small incision was made in the skin between the 12th and 13th ribs approximately 15 cm from the dorsal midline. The biopsy trocar was inserted through the body wall and peritoneum and introduced into the liver parenchyma, and a liver sample was collected. Following the biopsy, the cutaneous incision was sutured and an antiseptic agent was applied to prevent infection. An i.m. injection of an analgesic was administered 1 h following the procedure to alleviate postsurgical discomfort. Most calves were able to stand within 2 h after the biopsy. The entire procedure, which could be performed by a single individual, usually required about 20 min from initial sedation until skin closure. Although liver samples of up to 500 mg were obtained, most samples weighed 75 to 150 mg (wet weight). A total of 156 liver biopsies were performed on 33 calves. Complications due to the biopsy procedure were observed in only two calves. Therefore, this procedure can be useful for studies designed to monitor changes in liver composition or enzyme activities over time.

Previous use of iodophors at 75 mg or higher of active iodine per liter to disinfect the surface of trout and salmon eggs during water hardening has often resulted in higher egg and fry loss than when eggs remained untreated. An iodophor solution containing 50 mg active iodine per liter was used to disinfect freshly fertilized eggs of fall chinook salmon (Oncorhynchus tshawytscha) during water hardening for 30 min. This treatment produced no significant increase in mortality of eggs and fry above that in untreated groups water-hardened with no iodophor.

To the Editor. —I commend Strand et al 1 for their interesting and informative article detailing the overall rate of blood culture contamination in an emergency department and the lower rate obtained with iodine tincture compared with iodophor skin preparation. Their data also allow some interesting conclusions to be made about the cost per pathogen-positive blood culture. Of 8467 blood cultures, 626 (7.39%) yielded a pathogen, and 421 (4.97%) grew a skin contaminant. These data are similar to a smaller study including emergency department and inpatient blood cultures, where of 917 blood cultures, 57 (6.21%) yielded a pathogen and 13 (1.41%) were deemed contaminated. 2

Objective. —To determine if iodine tincture is a more effective skin antiseptic for blood culture collection than povidone-iodine, an iodophor. Design. —Pairwise comparisons across phases. In phases 1 and 3, blood culture skin preparation was performed with the iodophor; in phases 2 and 4, skin preparation was performed with iodine tincture. Setting. —Emergency department of a large urban teaching hospital. Patients. —All adult patients seen in the emergency department who had blood cultures collected because a systemic bacterial infection was suspected. Main Outcome Measure. —The blood culture contamination rate for the iodophor and iodine tincture skin preparations. Results. —A total of 8467 blood cultures were collected during the study, and 421 (4.97%) were classified as contaminated. The contamination rate for the blood cultures collected using the iodophor was 6.25%, and the contamination rate for the cultures using iodine tincture was 3.74%; this difference is statistically significant ( P Conclusions. —The effectiveness of the skin antiseptic may be an important factor in determining contamination rate in blood culturing. If these results are confirmed by others, then institutions that have a high blood culture contamination rate when using an iodophor for skin preparation should consider changing to iodine tincture. ( JAMA . 1993;269:1004-1006)

The purpose of this study was to compare a traditional two-step method of preoperative skin preparation using aqueous iodophors with a one-step method using an iodophor-in-alcohol solution. Sixty patients having clean total joint surgery were randomly divided into two preoperative skin preparation groups (30 in each). In one group, the skin was prepared with a traditional five-minute aqueous iodophor scrub followed by the application of an aqueous iodophor solution as a paint. In the other group, the skin was prepared with a one-step application of a water-insoluble iodophor-in-alcohol solution applied as a paint. Bacterial colony counts were made by sampling the incision area with culture plates before skin preparation and just prior to wound closure. The one-step application of a water-insoluble iodophor-in-alcohol solution was equally as effective as the traditional scrub-and-paint preparation in reducing the number of bacteria about the operative site. The water-insoluble preparation also resulted in significantly improved drape adhesion as compared to the standard scrub-and-paint procedure. The one-step water-insoluble iodophor-in-alcohol solution fulfills the requirements for an operative site skin preparation and significantly improves drape adhesion. It is more convenient, easier to apply, less time consuming, and potentially less expensive than the traditional scrub-and-paint method.

The antimicrobial activity of two chlorinated sanitizers, sodium hypochlorite and sodium dichloroisocyanurate, a chlorinated cleaner, and an iodophor were determined in the presence and absence of egg solids. Sodium hypochlorite and sodium dichloroisocyanurate were tested against Salmonella typhimurium using concentrations of about 270 ppm active chlorine near pH 7. The test organism was killed rapidly by the sanitizers in water. When 1.0% egg solids was added, antimicrobial activity rapidly decreased and was slight after 1 hr, although a chemical test showed 17 to 30 ppm residual active chlorine. The commercial chlorinated cleaner gave a pH of 11.2, and Streptococcus faecalis was used as the test organism since salmonellae do not survive at this pH. This cleaner at 240 ppm active chlorine was effective in water but was ineffective against the test organism after incubation 30 min with 1% egg solids despite the presence of 52 ppm residual active chlorine by the chemical test. Tests in a commercial plant demonstrated that active chlorine chemicals added to wash water were completely inactivated in a few minutes. An iodophor was tested at a molar concentration equivalent to that used with chlorine compounds (949 ppm I2) and also at 25 ppm I2, both at acid pH's since iodophors were ineffective at neutral or alkaline pH's. At 25 ppm I2, the iodophor was ineffective when egg solids were added. At 949 ppm I2 and pH 3.52 the iodophor rapidly killed the salmonellae even after incubation for 1 hr with 1% egg solids and 710 ppm I2 remained. Maintaining bactericidal levels of residual chlorine in egg washwater appears impractical. Use of a iodophor might be effective but would be costly and would require major changes in washing procedures.

SummaryAn automatic device, which infuses disinfectant into the mouthpiece of the liner of the milking machine cluster as teatcups are removed, is described. Application at this time avoids any delay in disinfection, reduces the workload in the parlour and increases reliability of application. The teats of 20 cows were contaminated before each milking by immersion in a suspension of Staphylococcus aureus and Streptococcus agalactiae and then disinfected manually or automatically with iodophor after milking. Str. agalactiae was recovered from < 5% of swabs and there was no difference between the results from the two methods. Neither method of disinfection was as effective against Staph. aureus and the recovery rate was significantly greater for the automatic method for both swabs from teat barrel (P < 0·05) and teat apex (P < 0·001). Rates of intramammary infection for quarters automatically or manually disinfected were similar and low (3/40 v. 6/40 respectively). The automatic method facilitates cluster removal by relieving vacuum and decreasing frictional contact at the mouthpiece lip, and utilizes approximately half the quantity of disinfectant used by manual dipping (0·9 v. 1·9 ml/teat). However, iodine contamination in the milk from the iodophor teat disinfectant was significantly increased from 14·4 to 102·2 μg I2/100 ml milk when no backflushing was practised.

SummaryThe bactericidal activities of various concentrations of 3 disinfectants commonly used for teat disinfection were compared in vitro using small discs of pig skin previously contaminated with Staphylococcus aureus. Solutions containing 40 g/1 Na hypochlorite, 25 or 50 g/1 chlorhexidine digluconate or iodophor containing 5 g/1 iodine were found to have equivalent or superior bactericidal activity to a solution containing 10 g/1 Na hypochlorite. This in vitro technique offers a convenient alternative to in vivo tests for teat disinfectants and with minor modifications could be applicable to the testing of skin antiseptics in general.

Two hundred and thirty-two cows were assigned alternately to complete dry cow therapy (infusion in all quarters on the day of drying off) or selective therapy (infusion in all quarters if a history of mastitis, California Mastitis Test score of +2 or +3 in any quarter, or if cell counts from bucket milk samples as determined by the membrane filter-deoxyribonucleic acid procedure were above 500,000 cells/ml). A dry cow product containing 10(6) units of procaine penicillin G and 1 g of dihydrostreptomycin in a slow release base was used. A 1% iodophor teat dip was used throughout the experiment. Infections of Staphylococcus aureus, Streptococcus agalactiae, other streptococci, and gram negative rods were eliminated from 85.4% of the infected quarters with complete therapy and 88.2% of the infected quarters with selective therapy. New infections occurred in 3.1% of quarters with complete therapy and in 6.5% of the quarters with selective therapy. Incidence of mastitis following the dry period was less with complete therapy compared to selective therapy (4.6% vs. 7.8% of the quarters). Selective therapy was as effective as complete therapy in eliminating existing infections. Complete therapy would be the choice in situations where new infections in dry period are of concern.

Potential reservoirs of pseudomonas within a neonatal ICU were evaluated. Colonization of infants by the same pseudomonas pyocin types could be classified as a cluster colonization (occurring over three to ten days), or serial colonization (occurring over longer times). Hands of personnel, sink surfaces, and solutions used to rinse nasopharyngeal catheters were identified as the principle reservoirs. Utilization of a liquid iodophor agent for hand washing and of acetic acid for rinsing suction catheters was associated with a significant reduction in the histologic evidence of sepsis and of pneumonia observed among autopsied infants.

A mixture of amphoteric surfactants with antimicrobial properties, C31G, was evaluated as a teat dip by a modified excised teat model. The model was modified to avoid misinterpretation of results from indigenous bacterial microflora on teats. In three experiments, bacterial numbers recovered from teats dipped in .75, 1.5, and 3.0% solutions of C31G were compared with bacteria recovered from undipped teats (negative controls) and teats dipped with 1.0% iodophor (an effective teat dip). Mean log reductions of teat end concentrations of Stapbylococcus aureus, Streptococcus fecalis , and Escbericbia coli were determined in each experiment. Efficacy was greatest for the 3.0% solution of C31G with mean log reductions (Log reduction=Log 10 of controls—Log 10 of dipped teats) 3.53 for Stapbylococcus aureus , 2.89 for Streptococcus fecalis, and 3.16 for Escbericbia coli. Iodophor (1%) yielded mean log reductions of 3.26 for Stapbylocococcus aureus , 2.16 for Streptococcus fecalis , and 2.83 for Escbericbia coli . For all three organisms, number of viable organisms decreased with increasing concentrations of C31G. The efficacy of C31G should be evaluated in vivo.

The antimicrobial activity of various povidone-iodine formulations has been assessed against Escherichia coli, where the molecular weight of the polyvinylpyrrolidone has been varied between 10 000 and 360 000. Bactericidal activity was directly related to polymer molecular weight and could be attributed to molecular-weight-dependent changes in the proportions of free and available iodine. When bactericidal activities were related to those of diluted Lugol's iodine solutions, then formulation as an iodophor was observed to give an approximate doubling of activity. It is suggested that this molecular-weight-independent potentiation of iodine action could be related to alteration of membrane-conformation, rather than to concentration, by the polymer, of iodine at its target.

TWO strains of V parahaemolyticus T-3765-l and SB04-422, were exposed to chlorine and iodophor solutions (laboratory and commercial). The effectiveness of both the chlorine and iodophor treatments was enhanced under acidic conditions. At 20°C and pH 7, the effectiveness of the iodophor was similar to that of chlorine in the destruction of V. parahaemolyticus. The iodophors were superior to chlorine in the destruction of V. parahaemolyticus at 0°C. In general, the prior growth temperature of the organism had little effect on its subsequent survival in either the laboratory iodophor or the chlorine solutions. In a simulated oyster blowing process, the iodophor again proved to be a more effective bactericidal agent than chlorine, and sensory evaluation of oysters exposed to the iodophor solution showed that there was no odor problem associated with such a treatment.

Efficacy of premilking teat disinfection (predipping) with good udder preparation was compared with good udder preparation alone on four well-managed, commercial dairy farms. Three teat dip formulations containing iodophor were used for predipping. Predipping reduced the rate of intramammary infection with major mastitis pathogens approximately 54%. Infection rate with esculin-positive streptococci and coliforms was reduced more than 51%. Udder infections with coagulase-negative staphylococci were not controlled by predipping.

SUMMARY A granular formulation (Byatran) combining a systemic fungicide (thiabendazole) and a bactericide (iodophor) was applied to the soil at the time of planting potatoes in 1974 and 1975. Observations indicated little or no effect of this material on the incidence of gangrene, common and powdery scab, black scurf, skin spot, silver scurf and black leg. The treatment was associated in both years with a slight but non-significant increase in yield of cv. Ulster Sceptre but not of cv. Majestic.

A teat dip containing 1.94% linear dodecyl benzene sulfonic acid and 12% glycerine, an anionic detergent formulation, was evaluated in two field trials on a commercial dairy. In Trial 1, the teat dip was compared to an undipped control in a split-herd design. Incidence of infection with Streptococcus agalactiae was reduced 57.8%; infections with presumptively identified Staphylococcus aureus were not reduced. Milking machine function and milking procedures may have affected teat dip effectiveness and incidence of udder infection. Streptococcus agalactiae was eradicated prior to Trial 2 in which the detergent teat dip was compared to a 1% iodophor product of proven efficacy. Incidence of Staphylococcus aureus infection was 40.5% lower in the detergent than in the iodophor group. Taxonomic studies on Staphylococcus species indicated that presumptive microbial identification resulted in erroneous conclusions concerning efficacy of the teat dip products. Importance of speciation of staphylococcal isolates is discussed.

Efficacy (reduction of new intramammary infections) was determined against Stapbylococcus aureus in 14 trials and against Streptococcus agalactiae in 5 trials. Against Stapbylococcus aureus seven 1% iodophor products had an average efficacy of 89.9% while three .5% iodophor products averaged 76.4%. A solution of sodium dichloro-s-triazenetrione reduced infections 79.0% and 2% dodecyl benzene sulfonic acid was 50.4% effective. Efficacies of two quaternary ammonium products at .18 and .5% were 84.8 and 60.9%. A placebo vehicle and .15M saline as teat dips reduced infections 8.9 and 9.2%. Infection rates with Streptococcus agalactiae were low; efficacy ranged from 50.5 to 100.0%, average 65.6%. The model of experimental exposure provided a better estimate of effectiveness of a teat dip than would be possible under conditions of most commercial dairying.

Oil-based teat dips containing iodine at .5 and 1% were compared in a series of studies with two water-based iodophor products of the same concentration and also with undipped controls. When the two types of products were tested at .5% under conditions of natural infection, the water-based dip was four times more effective than the oil-based dip at preventing Staphylococcus aureus infections. In three subsequent trials teats were experimentally exposed to S. aureus and Streptococcus agalactiae. Five times more S. aureus infections developed in a group dipped with the oil-based dip at 1% iodine with an undipped control yielded no significant difference for S. aureus infections. The 1% iodine water-based product was nine times more effective in preventing S. aureus infections than the 1% oil-based product. Differences in the incidence of S. agalactiae infections were nonsignificant within the individual trials. Though ineffective in preventing udder infections oil-based products were effective in creating a supple condition of teat skin.

Methods of eliminating pacemaker infection are reported in a prospective study of ten years. The majority of 400 patients were in their 7th and 8th dec ade. All procedures were done in the operating suite. Skin was prepared with providine-iodine soap and solution and the surgeon's hands were scrubbed with an iodophor sponge. All patients were given prophylactic antibiotics, the major ity receiving cephalothin. No drains were used. Cephalic vein entry was used in almost all cases. The wound was irrigated with kanamycin solution. One third of the patients had risk factors such as diabetes, heart failure and temporary pacemakers. Pacemakers of ten different manufacturers were used. There was one infection in this series.

Udder preparations using premilking teat disinfectants, premilking teat dipping procedures, and types of paper towels were evaluated to determine their effects on bacterial counts in milk and on teats. Iodophor, sodium hypochlorite, and dodecyl benzene sulfonic acid teat disinfectant dips significantly reduced total bacteria in milk with no significant differences among disinfectants. Teats dipped with dodecylbenzene sulfonic acid had higher coliform counts, which may be attributed to the physical properties interfering with effective drying. Manual drying of teats with a paper towel further reduced bacterial counts in milk; length of manual drying time did not significantly change bacterial counts. Also, types of paper towels did not affect bacterial counts on teat ends. Data suggest that the benefit of manual drying in assuring dry teats is of primary importance compared with duration of manual drying and type of towel.

Cows were subjected to teat dipping in a commercial iodophor germicide twice daily for at least 7 days immediately before calving to assess efficacy of the practice in reducing new intramammary infection at calving. In a cold season and in a warm season, groups of about 35 cows successively calving were treated and were compared with similarly sized and selected control groups. There were no advantages for teat dipped over control cow groups for incidence of new intramammary infections at calving, for new infections that persisted for longer than 14 days after calving, or for new infections that required antibiotic therapy. Incidence of new infection in warm weather (27.3% of quarters) was twice that in cool weather (13.6%). The most frequently isolated pathogens were coagulase-negative staphylococci and Streptococcus uberis . Staphylococcus aureus infections were more likely to persist into the new lactation (83%) than were infections by other pathogens (38 to 57%).

SUMMARY Slurries made from mixtures of wettable powder formulations of fungicides in water or the mineral oil Actipron were applied to Didymella lycopersici Kleb. stem lesions on glasshouse tomatoes. Benomyl/Actipron completely arrested lesion development, but the other treatments, thiram/Actipron, Actipron, and water with captan, captofol, benomyl, benomyl and maneb, an iodophor, maneb, or thiram did not prevent lesion development. Benomyl/Actipron in the ratio of 1:1·5 of commercial products (wt/vol) gave the most satisfactory control of D. lycopersici stem lesions while minimising phytotoxicity. A fungitoxicant was recovered from tomato stems following application of the benomyl/Actipron mixture. With Actipron/benomyl the uptake of the fungitoxicant by the plants was greater than with the benomyl/water mixture, which was not as effective: it dried to a hard shell and lack of moisture may have impeded uptake of the fungitoxicant.

Results from the Food and Drug Administration's Total Diet Study on the nutrient element content of fluid whole cow's milk are presented and compared with previously published values. Whole milk was collected and analyzed yearly from 1975 through 1985. Yearly and overall means were similar for all elements except iron and iodine. The iron content of milk was generally low, but several samples had high levels. The distribution of iodine in whole milk was quite wide (0.002 to 0.094 mg/100 gm). The iodine content of milk is affected by the level of iodine added to cattle feed and by the use of iodophor sanitizing solutions used by the dairy industry. Overall mean levels of the elements in milligrams per 100 gm whole milk were: sodium, 42; potassium, 134; calcium, 106; phosphorus, 83; magnesium, 9.8; iron, 0.07; zinc, 0.37; copper, 0.009; manganese, 0.004; iodine, 0.034; and selenium, 0.001. Coefficients of variation were high (67% to 117%) for iron, copper, manganese, selenium, and iodine but ranged from 18% to 26% for the other elements. An 8-fl oz serving of whole milk is an excellent source of iodine, calcium, phosphorus, and potassium. It also provides some sodium, magnesium, zinc, and selenium but is not a reliable source of iron, copper, or manganese.

The effects of disinfectants on the mechanical properties and surface topographies were determined for 0.017 x 0.025-inch Nitinol and Titanal wires. Three disinfectants approved by the American Dental Association were tested at maximum antimicrobial concentrations: 2% acidic glutaraldehyde, chlorine dioxide, and iodophor. Bending and tensile tests were evaluated to determine whether the stiffness, strength, or range of the wires changed after disinfectant treatment. Laser spectroscopy was used to detect surface changes from corrosion or tarnish after treatment. No detrimental changes were detected in the mechanical properties or surface topography of either wire product after disinfectant treatment. Nitinol was found to be stronger and stiffer than Titanal. On average, Titanal exhibited five times more specular reflectivity than Nitinol.

SUMMARYThe report investigates the variation in results noticed when testing iodophor disinfectants in the presence of a 5% (w/v) yeast suspension.It was found that these variations were not related to individual iodophor formulations but bore a direct relationship with the storage time of the prepared yeast suspension.

Forty Holstein and Jersey cattle were assigned to four groups by milk production of Dairy Herd Improvement Association records. Cattle were on pasture and free-choice roughage supplemented with a concentrate and mineral mixture that was mixed without iodine supplementation. Teats of cows in each group were dipped for 27 days with chlorhexidine (controls) or iodophor teat dips with 1, .25, or .1% concentrations of iodine. Individual milk samples were taken on days 0, 20, and 27 for determination of iodine in milk. Mean iodine remained fairly constant, although there was a transitory increase for 1 and .25% dips at day 20. Mean iodine in milk (microgram/liter) for days 0, 20, and 27 were control: 31.3, 19.8, 14.7; 1.0%: 21.8, 51.5, 23.7; .25%: 34.5, 46.9, 36.7; .1%: 13.6, 14.5, 14.9. Iodophor teat dips did not add appreciable amounts of iodine to the bulk milk.

Toxicity of Wescodyne(R) and Betadine(R) to eyed eggs was not adversely affected by water hardness (as calcium and magnesium) or by exposure periods up to 60 min. Both iodophors were much more toxic below pH 6.0 than at pH 8.0. In general Wescodyne was slightly more toxic than Betadine. Significant egg loss occurred if freshly fertilized eggs were water-hardened in either iodophor at 100 ppm of iodine, but egg loss at 25 ppm of iodine or at 100 ppm if the eggs were disinfected 30 min after water hardening was comparable to the control. Also, there was no effect on the egg mortality or fry development following single or multiple exposures after eggs were water hardened. At pH 6.0 and above, Wescodyne and Betadine at 100 ppm iodine in a 15-min dip would be safe to use on rainbow trout eggs at any stage of development after water hardening. Recommendations and precautions for hatchery use are given.

Complementary use of alkaline and acidic detergents within one system for soak cleaning was examined. A cleaning simulator was used to determine the changes in soil and bacterial numbers on stainless steel and rubber surfaces over 28 soiling and washing cycles (each of 12 h) with four cleaning systems. The soiling milk was inoculated with 5 × 105 Streptococcus faecalis and 5 × 105 Escherichia coli colony forming units/ml. In one system the soiling milk was followed by a wash with a chlorinated - alkaline detergent (20 C) and two rinses of cold water (20 C) and an intercycle period of 9.5 h. The second system was the same as the first, except an acidic detergent (20 C) was substituted for the final rinse every 9th cycle. In the third system, the same acidic detergent was used in every cycle, and in the fourth, an iodophor was used as the final solution in every cycle. The experiment demonstrated that the complementary use of alkaline and acidic detergents is ineffective in the soak-cleaning situation as acidic detergents aggravate accumulation of soil under these circumstances. Although the periodic application of a sanitizer did not influence soil accumulation, it transiently affected numbers and types of microorganisms on the surfaces. Under these conditions, the efficiency in bacterial control of the four systems was related not to the detergency, but to the performance of the sanitizer used in the system. The two substrates varied greatly in the absolute and relative amounts of soil which were deposited upon them - these differences affecting the numbers of bacteria which the surfaces supported. Neither S. faecalis nor E. coli grew during the intercycle period of any system (9.5 h, RH 90%, 30 C).

Two iodophor preparations, Betadine and Prepodyne, used as handwashing antiseptics in two well-baby nurseries, were compared. A total of 1,806 cultures were evaluated. They were taken a) from nurses' hands after washing with either of the products to determine the effectiveness in removing bacteria from the skin surface, b) from the babies' umbilicuses to assess the level of colonization of the infants' skin surfaces to which nurses were exposed during infant bathing, and c) from the nurses' hands immediately after completion of the babies' bathing routine. The results obtained indicated that the products are equally effective in eliminating bacteria in a routine handwashing procedure in similar circumstances. Both presented a comparable skin drying effect after repeated exposures and did not lead to any allergic reaction in the present trial.

A commercial teat dipping preparation formulated to have good detergence and emollience but no germicidal activity and a commercial iodophor teat dip of 1% available iodine were tested sequentially for efficacy in preventing new intramammary infection. Teats on one side of the udder of 150 Jersey cows were dipped in the test material after each milking; the opposite teats were undipped controls. Duration of the trials was 12 months for the detergent-emollient dip and 8 months for the iodophor dip. Intramammary infection was determined by bacteriological evaluation of monthly quarter foremilk samples. Neither dip was associated with reduction in new infection rate. Possibly because of its low level of total infection and of Staphylococcus aureus and its lack of Streptococcus agalactiae, this herd was unable to demonstrate prophylaxis against intramammary infection by postmilking teat dipping and was unsuitable for testing efficacy of the tested products.

The incidence of thyrotoxicosis in northern Tasmania rose significantly in 1964, two years before an epidemic of iodine-induced thyrotoxicosis was precipitated by the addition of iodate to bread to prevent goitre. Each time older patients accounted for most of the increase. The 1964 increase was probably iodine-induced as the use of iodophor disinfectants on dairy farms, which causes iodine residues in milk, began in 1963 and a fall in the prevalence of goitre in young children suggested an increase in dietary iodine at about that time. A further small increase in thyrotoxicosis in 1971 may also have been iodine-induced as it followed an extension of the use of iodophors. Dietary iodine is rising substantially in many places because of high iodine levels in milk and the use of iodine compounds in automated bread making, and this may be causing unsuspected iodine-induced thyrotoxicosis. Dietary iodine should be monitored regularly and clinicans alerted to any rise. Contamination of common foods with iodine should be more strictly controlled.

Representative food spoilage, indicator, and pathogenic organisms were exposed to newly developed imported iodophors and widely used representative domestic germicides that included iodophors. The organisms used in these experiments included Salmonella derby, Escherichia coli, yeast of the genus Candida, Pseudomonas aeruginosa, Staphylococcus aureus. Streptococcus lactis, and spore of Bacillus licheniformis. Results of the germicide experiments showed generally similar effectiveness by iodophor and hypochlorite. Both were superior to the quaternary ammonium compounds (QAC) when used at much lower concentrations (12.5 and 25 for the halogens and 50 and 200 ppm for the QAC). The iodophors exhibited a consistently greater rate of destruction of yeast cells than the hypochlorite when low concentrations of germicide were used. A procedure to more closely simulate actual use of germicides in food and dairy industries also was employed in this study. Special polished metal strips were inoculated with organisms and exposed to an iodophor, a sodium hypochlorite, and a QAC for 15, 30, 60, and 300 sec. Again the halogen compounds were superior to the QAC in destroying the bacterial cells, especially against gram-negative species including Salmonella.

Labyrinthuloides haliotidis, a pathogenic parasite of juvenile abalone (Haliotis kamtschatkana and Haliotis rufescens), was destroyed by a 20-min exposure to 25 mg chlorine per l of sea water. This parasite showed high resistance to six other potential disinfectants: formalin, iodophor, isopropanol, methylene blue, malachite green, and copper sulfate. The antibiotic fungicide cycloheximide at 1–2 mg per l for 23 h per day on 5 consecutive days proved efficacious. However, this treatment had three disadvantages: (1) it was detrimental to some diatoms upon which the abalone fed, (2) it was ineffective against non-growing but infective zoospores of L. haliotidis and thus reinfection usually occurred within 2–3 weeks following treatment, and (3) it resulted in cycloheximide resistant forms of L. haliotidis. Two different combinations of three sulfonamides (sodium sulfamethazine and sodium sulfathiazole with either sodium sulfapyridine or sodium sulfacetamide), especially in conjunction with neomycin sulfate, partially retarded the progression of the disease. Nine other therapeutic agents (betanaphthol, acriflavin hydrochloride, rivanol, furanace, oxytetracycline, chloramine-B, oxolinic acid, metronidazole, and neomycin sulfate) showed little or no activity against L. haliotidis at concentrations higher than would be feasible for use in an abalone culture facility.

The efficacy of hygienic hand wash procedures for food handlers using germicidal soaps and hand dips was studied by measuring changes in numbers of microorganisms released from hands before and after each of two successive 15-s treatments. Both hand rinse and finger tip imprint sampling techniques were used. The experiment consisted of two (6 × 6) Latin square designs, each including a non-germicidal soap control. Of the hand dip agents, including sodium hypochlorite (50 ppm available chlorine), iodophor (25 ppm available iodine) and a quaternary ammonium compound (QAC) (930 ppm benzalkonium chloride), only the QAC gave a statistically significant decrease in the number of bacteria released when tested by the finger imprint technique. This experiment included a bar soap containing 1.0% trichlorocarbanilide which gave results equivalent to the non-germicidal soap control. Of the hand wash agents, 4% chlorhexidine gluconate and iodophor (0.75% available iodine) resulted in significant decreases in numbers of bacteria released when tested by either sampling technique. Products containing Irgasan DP 300 (0.25% active ingredient at the use concentration), tribromosalicylanilide (0.5%) and para-chloro-meta-xylenol (0.325%) were no better than the non-germicidal soap control under the conditions of this experiment. Identification of 3,591 aerobic isolates from finger imprint plates indicated that Staphylococcus epidermidis and Micrococcus spp. were the predominating organisms (85.3%) released from the hands.

Iodine in the atmosphere is derived largely from seawater. It is probable that the biological production of methyl iodide is important in this transfer. Subsequent photolytic dissociation and oxidation of the methyl iodide, together with other inputs, with partial sorption of the products by aerosols, results in the atmospheric iodine being distributed between various gaseous and particulate forms. Atmospheric iodine is the major source of the iodine in soils, and the process of enrichment continues throughout soil formation and development until ultimately an equilibrium concentration is attained. The retention of iodine in soils is due mainly to the organic matter and hydrous oxides of iron and aluminum. In humid areas, only small proportions of the total soil iodine are soluble in water or available for uptake by plants. The atmosphere is also a direct source of iodine for plants, and in some situations may be more important than the soil. Iodine may be lost from soils by leaching, volatilization, and removal in crops, but the magnitude of these processes is difficult to assess. However, the amounts of iodine reported in groundwaters, and in rivers and lakes remote from human activity, suggest that some leaching of iodine is widespread. Increased amounts of iodine occur in rivers receiving effluent from sewage works. Milk and milk products are now major dietary sources of iodine because their content is often increased by concentrate feedingstuffs supplemented with iodine and/or by the use in dairies of iodophor detergents and sterilants.

A strictly controlled field trial was designed to assess the value of an iodophorpost-milking teat disinfectant in the prevention of new mastitis infections in a 132 cow herd. The disinfectant was applied by a hand spray, a method acceptable, effective, and less costly than conventional teat dipping methods. Only the left side of the udder was treated, the right quarters acting as controls. Dry-cow therapy and other methods of mastitis control were already practised, and no change in routine was introduced apart from half-udder teat spraying. Fifty-eight new cases of mastitis were found to occur on the teat-sprayed side, compared with 91 in the untreated quarters; 35 and 23, respectively, were clinical. No Group B streptococci existed in the herd, and the principal reductions were in Group C streptococci and coagulase-negative staphylococci, the percentages of which were halved. The percentage of coliform infections on the teat-sprayed side was, in contrast, doubled. The incidence of new clinical and subclinical disease without infection was in reverse ratio to that of infections, being 29-9 per cent higher in the quarters which were teat-sprayed. Analysis of cumulative CMT reactions from regular monthly surveys indicated that exponential cell-count values on each side of the udder were identical. Thus, while new infections were significantly reduced, overall cell counts were not, and there is clearly a need for further research into factors other than bacteria which may initiate teat damage and inflammatory changes in the udder.