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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↗
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↗
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↗
PubMed2026

Involvement of cross-genus phages in bacterial resistance to chlorine disinfection.

Chlorine disinfection resistance in pathogenic microorganisms poses severe environmental concerns and public health risks. While phages play critical roles in host adaptation to environmental stress, how poly-host phages contribute to bacterial resistance to chlorine disinfectants remains poorly understood. Here, we investigated shifts in the population dynamics, transcriptional profiles, and function potentials of cross-genus phage-bacterial communities under exposure to chlorine disinfectants in a continuously operated anaerobic-anoxic-oxic system over a 92-day period, using integrated metagenomic and metatranscriptomic approaches. In the presence and absence of chlorine disinfectants, the genomic abundance and diversity of phage and bacterial communities showed similar variation trends, and the community structures of both exhibited clear differences. A strong significant positive correlation was observed between phage and bacterial diversity under chlorine exposure (R&#x202f;=&#x202f;0.975, p&#x202f;=&#x202f;0.00,057), whereas no significant correlation was detected in the absence of chlorine disinfection (R&#x202f;=&#x202f;-0.314, p&#x202f;=&#x202f;0.613), suggesting that chlorine disinfectants may enhance phage-bacteria interactions. Host-associated phages exhibited high consistency with their corresponding putative hosts in terms of genomic abundance (M2&#x202f;=&#x202f;0.0945, p&#x202f;=&#x202f;0.001) and transcript abundance (M2&#x202f;=&#x202f;0.3668, p&#x202f;=&#x202f;0.001), and they were also significantly correlated with cross-genus phages in both genomic abundance (R&#x202f;=&#x202f;0.97, p&#x202f;<&#x202f;2.2e-16) and transcript abundance (R&#x202f;=&#x202f;0.83, p&#x202f;<&#x202f;2.2e-16), which collectively suggests the critical role of cross-genus phages in the resistance of microbial communities to chlorine disinfectants. Bipartite association network analysis shows that cross-genus phages carry highly homologous genes to their putative hosts and may be involved in the horizontal transfer of these genes among bacteria. These homologous genes are involved in DNA repair, redox balance regulation, environmental stress adaptation and efflux pump functions, suggesting a synergistic role between cross-genus phages and their putative hosts in chlorine resistance. Our findings reveal that cross-genus phages can contribute to the resistance of bacterial communities to chlorine disinfectants, providing the theoretical foundation for evaluating the role of poly-host phages in microbial communities.

Chlorine resistance↗
PubMed1979

The relative resistance of f2 bacteriophage to inactivation by disinfectants.

f2 bacteriophage in the presence of fetal calf serum (at a final concentration of 10%) was exposed to six commonly used disinfectants for times of 10, 20 and 30 sec. At the end of exposure times skim milk neutralized the disinfectant activity and residual virus was assayed using the plaque technique. The 6 disinfectants considered were Javex, sodium hydroxide, ethanol, Wescodyne, One Stroke Ves-Phene and Sonacide. A 0.25% (w/v) solution of sodium hydroxide and 1/50 Javex (1200 parts/10(6) chlorine) were the most effective of the six disinfectants considered since 10(5) f2 bacteriophage were inactivated in 30 seconds in each instance. Since a 0.25% (w/v) solution of sodium hydroxide had a pH of 12.5 this made it too caustic to use as a disinfectant in many practical situations. It was concluded therefore that Javex at some dilution less than 1/50 (greater than 1200 parts/10(6) chlorine) was the most practical of the six disinfectants to use. Ethanol (95%, v/v) inactivated 10(3) f2 bacteriophage in 30 seconds while 1/20 Wescodyne and undiluted Sonacide inactivated 10(1)-virus particles. Ves-Phene at a dilution of 1/50 was a completely ineffective virucide during the 30 sec exposure. The resistance of f2 bacteriophage to inactivation by these six disinfectants was compared with that of echovirus 11 and coxsackievirus B5. In all instances except exposure to undiluted Sonacide, f2 was comparable in resistance to inactivation and in many cases had greater resistance.

Coliphages↗
PubMed2026

Genomic characterization of efflux pumps and putative small multidrug resistance (SMR)-like transporters in disinfectant-tolerant coagulase-negative staphylococci from a Vietnamese hospital.

Coagulase-negative staphylococci (CoNS) are common inhabitants of healthcare environments and can serve as reservoirs of antimicrobial resistance determinants. However, the relationship among disinfectant tolerance, efflux-associated phenotypes, and multidrug resistance in environmental CoNS remains incompletely defined. Here, 51 staphylococcal isolates were recovered from high-touch hospital surfaces in Hanoi, Vietnam, and 14 isolates showed elevated MICs to at least one disinfectant, including benzalkonium chloride, chlorhexidine gluconate, or hydrogen peroxide, relative to Staphylococcus aureus ATCC 25923. These isolates also displayed multidrug-resistant phenotypes. Moreover, ethidium bromide accumulation assays revealed a clear efflux-associated phenotype, and representative isolates exhibited biofilm-forming ability. Whole-genome sequencing of three representative isolates reclassified SDH.B1 and SDH.B3 as Staphylococcus nepalensis-a CoNS species rarely documented in hospital AMR surveillance-and confirmed SDH.B7 as Staphylococcus haemolyticus. To our knowledge, this is among the first reports of S. nepalensis carrying mecA together with the disinfectant efflux gene qacG, and a set of putative small multidrug resistance (SMR)-like transporters in a hospital environment from Southeast Asia. In addition, six putative SMR-like proteins were identified. Phylogenetic and structural analyses suggested relatedness to YkkC/YkkD-like systems, although their transport activity remains to be experimentally verified. These findings identify environmental CoNS as reservoirs of disinfectant tolerance and multidrug resistance in hospital settings and provide a basis for future functional investigation of putative SMR-like transporters.IMPORTANCEHospital environmental CoNS are often dismissed as low-priority contaminants, yet they may persist under disinfectant pressure and carry clinically relevant resistance determinants. Here, disinfectant-tolerant CoNS recovered from a Vietnamese hospital combined multidrug resistance, efflux-associated phenotypes, and biofilm-related traits. Genome analysis further revealed known qac genes and six putative SMR-like proteins that merit functional testing. These findings support inclusion of environmental CoNS in infection-prevention surveillance and disinfectant stewardship programs.

Staphylococcus haemolyticus↗
PubMed1978

[Hydrogen peroxide, chloramine T and chlorhexidrine in the disinfection of acrylic resin].

The effectiveness of 3% h drogen peroxide, 5% chloramine T and 0,5% chlorhexidine gluconate solutions in disinfection of acrylic resine plates massively infected with oral flora was analysed. The acrylic resine plates used for investigations, were infected in vitro with mixed salivary flora characterized by small numbers of yeast-like fungi (1st group), or great number of these microorganisms (2nd group). Infected plates were exposed to solutions of analysed disinfectants during various time periods. After rinsing or inactivation of disinfectant residues, acrylic plates were put into bacteriological medium and incubated during 7 days period in 37 degrees C. The results of this study indicated the effectiveness of acrylic plates disinfection to be dependent on used disinfectant, time of exposition, and microorganisms present on the surface of acrylic resine. The solutions of disinfectants were less active in the cases of plates infected with material containing great numbers of yeast-like microorganisms. Among analysed disinfectants 0,5% solution of chlorhexidine was characterized by most effective and rapid activity, whereas 3% solution of hydrogen peroxide was found to be the least effective.

Acrylic Resins↗
PubMed1978

The relative effectiveness of commonly used disinfectants in inactivation of coxsackievirus B5.

Coxsackievirus B5 in the presence of fetal calf serum was exposed to six commonly used disinfectants for times of 10, 20 and 30 s. At the end of exposure times skim milk neutralized the disinfectant activity, with residual virus assayed by the plaque technique. The six disinfectants considered were Javex, sodium hydroxide, ethanol, Wescodyne, One Stroke Ves-Phene and Sonacide. Although 95% (v/v) ethanol was significantly more virucidal than dilutions of the other five disinfectants tested causing a 10(6) reduction in 20 s, it may not be practical to use in many instances. Next to 95% (v/v) ethanol, 1/75 (800 parts/10(6) Javex, 0.25% (w/v) sodium hydroxide and 1/200 Wescodyne were the most effective virucides. These disinfectants were equal in effectiveness causing a 10(5) reduction of coxsackievirus B5 in 30 s. Of these three disinfectants Javex is the most practical to use since sodium hydoroxide is caustic and Wescodyne is selective in its virucidal action. Undiluted Sonacide was a less effective virucide causing a less than 10-fold reduction of coxsackievirus B5 in 30 s. A 1/50 dilution of One Stroke Ves-Phene was the least effective virucide tested since it did not significantly inactivate coxsackievirus B5 in 30 s.

Animals↗
PubMed1979

[Suitability of chemical neutralizers applied for disinfection control on commercial animal husbandry objects].

A study on the effect of various neutralizers of the most widely spread means of disinfection applied in animal rearing was made. For that purpose twin lecytine was tested for quadruple ammonium compounds: twin--for phenolic compounds, natrium thiosulfate--for iodoformium and chlor-containing compounds, as well as natrium sulfite--for formalin. As test micro-organisms were used Staph. aureus Sg 511, E. coli 078, and Ps. aeruginosa. The investigations were performed after the suspension method with dilutions in geometrical progressions. It was established that for the disinfection by quadruple ammonium compounds 3% twin-80 plus 0.3% lecytine is suitable as neutralizer. In disinfection with phenolic compounds the 1% twin-80 solution gives good results. As neutralizer of formalin disinfection 2% natrium sulfite solution can be successfully used. For iodoformium disinfection or disinfection with chlor-containing compounds good neutralizing effect can be achieved by 1% solution of natrium thiosulfate.

Animal Husbandry↗
PubMed1979

Evaluation of soft contact lens disinfection in the home environment.

Recent reports of bacterial corneal ulcers in cosmetic soft contact lens wearers prompted an evaluation of one possible source of contamination, inadequate home disinfection of the lenses. Twenty-nine patients were asked to come for an early morning examination. They were told not to wear their lenses so their usual home disinfection procedure could be observed. On arrival, extensive bacterial and fungal cultures were taken of the solution in the previously unopened cases. Ten of the 29 patients (34.5%) had contaminated cases. Some patients did not follow the manufacturer's disinfection guidelines. The current disinfection procedure has repeatedly proven adequate in the laboratory. However, the practical fact is that a substantial percentage (34.5% in this study) of soft lens wearers are inadequately disinfecting their lenses. This serves as a possible source of contamination leading to bacterial corneal ulcers.

Activities of Daily Living↗
PubMed1977

[Agents and methods for the disinfection of the integument of animals before slaughter].

Experiments were carried out to test the disinfection effect of some agents, such as chloramine B, chloramine B+ surface active substances, vofasteril (peracetic acid), perfumaric acid, and bradofen on a dry skin or when applied immediately after washing--in buffaloes, cattle, and swine. Parallel trials were conducted under conditions of the practice as well. Escherichia coli and Staphylococcus aureus were used as model organisms. Results showed that best disinfection effect have 1.5 percent chloramine B and 0.5 per cent peracetic acid (for dry skins), and 3.0 and 0.8 per cent of the same agents when applied on wet skins (immediately after washing). The animals should be slaughtered not earlier than 10 min and not later than 30 min following disinfection. The effect of disinfection is read best on impression preparations of agar (in aluminum folio).

Abattoirs↗