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At least 19 recordsLinked to original sources
PubMed1977

[Usability of three alcohols for a standard disinfection method to be employed for the evaluation of procedures for the hygienic disinfection of hands (author's transl)].

Following a former suggestion (4) always to evaluate, the efficacy of procedures for Hygienic disinfection of hands in comparison with the results of a certain standard disinfection method, Ethanol, iso- and n-Propanol were tested in various concentrations and for various times of action on their usability in such a standard method. The disinfecting power was dependent upon (i) the alcohol (Ethanol less than iso-Propanol less than n-Propanol), (ii) the concentration (Ethanol: 60 less than 70 less than 80% ml/ml, iso-Propanol: 50 less than 60 less than 70, n-Propanol: 40 less than 50 less than 60 = 70) and (iii) the time of action (0,5 less than 1 less than 2 min). n-Propanol proved to be the fastest acting disinfectant. However, as standard disinfection method iso-Propanol (60% ml/ml) being used for 1 min has been proposed. Furthermore, the following results that have been obtained also in former investigations (8) could be confirmed: (i) there is no systematic difference between the release of test-bacteria from the fingertips of right and left hands of test-persons (ii). The efficacy of procedures for Hygienic disinfection of hands is besides other factors influenced by the testpersons. This factor may be eliminated by using the same testpersons for both, the disinfection procedure under investigation and the standard method. The results of both may, then, be related to each other and the efficacy of the former may be evaluated in comparison to the latter.

1-Propanol↗
PubMed1975

[Testing a disinfectant used for chemothermic disinfection (author's transl)].

Experiments were carried out to test the bacteriological effectiveness of an aldehyde-based disinfectant used for the chemothermic disinfection of instruments. The product is designed to be added to instrument washing machines whereby the temperature should be 65 degrees C. The death rate by means of heat (65 degrees C) of 4 different species of bacteria (Staphylococcus aureus, Escherichia coli, Pseudomonas aeruginosa, Proteus vulgaris), which were all suspended in four different media, was determined. E. coli proved to be the most thermoresistant. It was not possible to destroy all the bacteria within one hour. The disinfectant alone was also not sufficient. The suspension, the instrument-disinfection- and the carrier-tests were based upon the "DGHM-Richtlinien". They were, however, carried out in the water bath at 65 degrees C so that the influence of the temperature and the disinfectant could be determined simultaneously. Good results were obtained with this combination of heat and disinfectant. Fungi and mycobacteria were also destroyed.

Bacteria↗
PubMed1978

Bacterial contamination of heat-sterilized, heat-disinfected and chemically-disinfected haemodialysis monitors.

The bacterial contamination of one heat-sterilized, three heat-disinfected and four chemically-disinfected monitor types was evaluated before and after dialysis. All monitor types were contaminated. In the heat-treated monitors the level of contamination varied with the intensity of the heat treatment and the technical design. They were less contaminated than the chemically-disinfected recirculating single-pass monitors. The latter were contaminated to a marginal degree, irrespective of the quality of the water supply. Each monitor showed a characteristic microbial flora, indicating that recontamination occurred from the same persistent focus. Aquired antibiotic resistance characters were rare among the potential human pathogens isolated from the dialysate. The level of contamination during dialysis is determined by a complex of factors, including the mode of disinfection, the technical design of the dialysis equipment, the duration of the dialyses, and the flora of the dialysate.

Anti-Bacterial Agents↗
PubMed1977

[Study of the feasibility and conditions for disinfecting materials made of chemical fibers by immersion in solutions of several disinfectants].

The authors studied the disinfection regimens of materials made of lavsan, capron, acetate, triacetate, viscose by the method of immersion into the disinfecting solutions of dichlor-I, chloramine calcium hypochlorite salt, potassium and sodium salt of dichlorisocianuric acid, sulfochloranthin, dichlordimethylhydantoin, catapin, amphocept, sodium metasilicate, hydrogen, peroxide, formalin, phenol, benzylphenol. As revealed, solutions of the following preparations could be recommended for the disinfection of linen made of chemical fibers at the foci of intestinal and droplet infection, except tuberculosis: sulfochloranthin (0.2%), amphocept and chloramine B (1%), sodium metasilicate, formalin, catapin, hydrogen peroxide with a 0.5% of washing solution (2%); these solutions gave a reliable effect in 60 minutes at room temperature, and in 20 to 30 minutes at a temperature of 40--45 degrees C.

Disinfectants↗
PubMed1977

Factors influencing the assessment of the pseudomonacidal activity of disinfectants by a quantitative suspension test. II. The post-disinfection recovery of surviving organisms.

Bacteria which have been treated by a disinfectant may be partially damaged so that they will be able to survive and to multiply only if all environmental factors are kept as optimal as possible. Otherwise no growth at all is obtained and the disinfectant solution will be wrongly considered as active. Therefore the technique of the post-medication recovery of surviving microorganisms is a matter of great importance. Since our aim is to elaborate a quantitative test, the counting technique using pour or streak plates is investigated here. In contrast to the results of viable counts of normally cultivated P. aeruginosa (Tables 1 and 2), the colony counts of phenol-treated bacteria gain higher figures when the spread plate method is used instead of the pour plate technique (Table 3). - Out of nine solid media examined (Table 4), four culture media are considered to be superior to the others (Table 5). They are Davis Agar, the Nutrient Agar of the German pharmacopoeia, the Nutrient Agar proposed by the APHA, and Tryptone Soy bean peptone Agar. Further investigation on the influence of the recovery medium is needed since there is stated that significant differences are obtained when three preparations of the same formulation are compared (Table 6). Finally the author observed that the volume of the culture medium affects the survival rate (Table 8). The recovery of disinfectant-treated bacteria is found to be very complex; further research on this domain should be encouraged.

Bacteriological Techniques↗
PubMed1977

[Experiments on disinfection of vaccinia virus embedded in scabs and/or at the hand].

Vaccinia viruses embedded in rabbit dermal scabs were subjected to physical and chemical disinfection procedures. Scabs were suspended in vitro without saline or in physiological saline, and left for 1 hour at 70 to 90 degrees C. A complete inactivation was achived only in those scab samples which had been incubated at 90 degrees C for 1 hour and suspended in physiological saline. Scabs which had been placed in a disinfecting apparatus (Vacudes 4000) filled with mattrasses consistently proved to be free of infectious vaccinia viruses in each of the chosen programs. In addition scabs were subjected to disinfection by means of chemical disinfecting agents. The scabs had been placed in a chemical disinfecting suspension and left there for 90 minutes. Complete disinfection was obtained with glutaraldehyde 2%, formaldehyde 2%, Lysoformin 2% or 3%, phenol 5% and chloramine T 2%. Complete disinfection was likewise achieved after 3 hours treatment with some alchohols (ethylalcohol 80%, isopropylalcohol 7%, n-propylalcohol 60%), Amocid 5% and formaldehyde 1%.0.5% formaldehyde caused complete disinfection when applied for 6 hours. The only exception was a Quat which did not disinfect fully even after 18 hours application. Concerning the tests to disinfect the hands complete disinfection occurs when using chloramine T (1.5%) or isopropylalcohol (70%) in 2 to 5 minutes. Further tests were performed with scabs which were placed in sick rooms that were terminally disinfected with formaline vapor. It could be confirmed that the usual terminal disinfection with formaldehyde vapor was unable to completely disinfect the scabs. It is necessary to double the amount of formaldehyde (10 g formaldehyde per cubic metre of space) and prolong the period of treatment to 24 hours to achieve a greater degree of disinfection rate.

Animals↗
PubMed1976

[Test for the efficacy of disinfectants at surfaces in test models. I. (communication:) Dependence of experimental results on the method of demonstration of surviving germs (swab and rinsing) (author's transl)].

For the testing of disinfectants at surfaces, the germs having survived at the surface are demonstrated by means of swabs according to the guide-lines of the Deutsche Gesellschaft fur Hygiene und Mikrobiologie (DGHM): after the period of exposure to the disinfectant, the surfaces were rubbed off with a damp swab, and the frictional surface of the swab was plated out on nutrient agar. The effectiveness of this technique was compared with the effectiveness of a rinsing method in a test model. In the rinsing process, the objects to be tested for surviving germs were shaken together with a suspension and with glass beads. Then the content of germs in the suspension was quantitatively determined by means of dilution tests and pour plates. The findings were evaluated according to the guide-lines for evaluation of the DGHM (less than or equal to 10 surviving germs = adequate efficacy). For the findings obtained by rinsing, the average number of surviving germs was also determined. For maldehyde solutions were used as disinfectants for the test models (time of exposure: 4 hours; temperature 22 to 25 degrees C). These disinfecting experiments were performed on raw smoothed as well as on varnished beech-wood. The experimental results showed that the criterion "less than or equal to X surviving germs" in itself does not mean clear evidence of the efficacy of a disinfectant. The one and only decisive criterion is the frequency of the statement that a certain disinfectant or a corresponding dilution of this disinfectant has shown adequate efficacy. Therefore, one single test according to the guide-lines of the DGHM is insufficient. The frequency of the finding "adequate efficacy" is not only dependent on the concentration of the disinfectant but also on the technique used for the demonstration of surviving germs. The swab method (according to the guide-lines of the DGHM) occasionally resulted in the finding "adequate efficacy" already if 10(4) to 10(5) surviving germs were demonstrable by the rinsing method. The range of formaldehyde concentrations for which the finding of adequate efficacy were present with a frequency between 20% (minimum) and 80% (maximum) amounted to 0.2-0.5% (varnished surface) and 1.1-2.5% (raw surface), respectively for the swab method. The respective figures for the rinsing method were 0.8-1.3% and 4.8-6.5%, respectively. When using the swab method, there is a slower increase in the efficacy of the disinfectant with concentration as compared with the rinsing method. The rinsing method is, therefore, more representative of the efficacy of a disinfectant than the swab method. On account of the results of this study, it is recommended for model experiments to recover the surviving germs quantitatively by the rinsing method and to determine their number.

Disinfectants↗
PubMed1975

[Virucidal activity of the disinfectant "gigasept" against different enveloped and non-enveloped RNA-and DNA-viruses, pathogenic for men. I. Investigation in the suspension test (author's transl)].

"Gigasept" is a highly efficient chemical disinfectant on the basis of succine dialdehyde and form aldehyde. The virucidal capacity was assayed in the suspension test procedure with different representative RNA and DNA viruses with and without an envelope, such as polio wild virus type I, coxsackie virus type B 3, adeno virus type 3, herpes virus type ) and vaccinia virus. Parameter for disinfectant activity was the virus inactivation kinetic, i. e. interdependence of titer reduction vs. disinfectant concentration and disinfectant contact time. A "minimal disinfection" was defined as a greater than or equal to 99.9% virus inactivation. A "disinfection per definitionem" must gain a titer reduction of greater than or equal to 10(3) ID 50 and absence of virus. According to these criteria all virus strains were inactivated by Gigasept regardless of absence or presence of serum, which was tested in a concentration of 40% calf serum. Disinfection per definitionem was achieved with Gigasept concentrations of 3% after 60 min. or 5% after 30 min. except for enteroviruses. This group of viruses has to be disinfected with a 10% solution for 4 hours or with a 5% solution overnight. Gigasept, on the basis of these results, can be classified as a highly effective virucidal disinfectant. As to the hepatitis virus group however, no data so far are available. An enterovirus - disinfection procedure is recommended in hepatitis risk areas, as long as test systems for hepatitis viruses are not developed.

Adenoviridae↗
PubMed1979

Limits to progressive reduction of resident skin bacteria by disinfection.

Antiseptic preparations used repeatedly to disinfect the skin caused a reduction in yield of resident flora to a low equilibrium level beyond which further reduction did not occur. This equilibrium varied with the antiseptic preparation used. In a comparison of three preparations, the lowest equilibrium level was obtained with 95% ethyl alcohol. The further reduction in yield of skin bacteria on using alcohol after repeated disinfection with an antiseptic detergent preparation ('two-phase' disinfection) was not paralleled by a further reduction when the preparations used in the two phases were reversed, the antiseptic detergent being used after repeated disinfection with ethyl alcohol. 'Two-phase' disinfection was therefore seen to be due to further reduction in skin bacteria from the low equilibrium obtained with the antiseptic detergent to the lower level obtainable by alcohol disinfection. When repeated disinfection to equilibrium with alcohol was followed by a 'second-phase' handwash with a non-antiseptic detergent and water, there was a large increase in the yield of skin bacteria. This finding supports the view that a low equilibrium level occurs when the reduction in density of accessible bacteria through disinfection is balanced by the emergence of bacteria drawn from deeper layers of the skin.

Bacteria↗
PubMed1979

Effect of disinfectants with and without usage of detergent for the flexible fiberoptic bronchoscope.

The purpose of this study was to find a safer, more rapid and easier disinfection process for the flexible fiberoptic bronchoscope (F.F.B.) by using ordinary disinfectants and a detergent. Klebsiella pneumoniae, Pseudomonas aeruginosa, Staphylococcus aures, E. coli, Serratia marcescens and Candida albicans were used as sources of contamination. The mixed bacterial growth preparations for contamination of the F.F.B. were the same as those previously mentioned in our study. Comparative bacteriological studies, between glutaraldehyde (GA) ethylalcohol (AL) and chlorhexidine (CHX) with and without usage of benzalkonium chloride (B.C.) solution and sterile water (W) as the detergent were performed and the following conclusions were obtained: 1. Contaminating microorganisms were reduced from 10(-3)/ml to 10(-4)/ml colony count after flushing with W and B.C. This procedure is very helpful for consecutive rapid disinfections or sterilizations of the F.F.B. 2. The effect of disinfectants with usage of a detergent was much better than without a detergent. Required immersion time in the disinfectants with detergent was reduced to periods as short as 60 seconds. 3. Of the three disinfectants, the most effective was CHX, GA next, and AL third. 4. Unsatisfactory disinfection occurred in some instances when there were functional disorders with the F.F.B. despite adequate amounts of disinfectant and detergent.

Bronchoscopes↗