Search PubMed⌕ Search

Biomedical subjects

G Reybrouck

Publications and source records attributed to G Reybrouck.

At least 37 records · Page 2Linked to original sources

Nosocomial urinary tract infections: etiology and prevention.

Nosocomial urinary tract infections arise mainly after transurethral diagnostic or therapeutic operations and are favored by the raised susceptibility of many hospitalized patients to infection. Besides strict establishment of the indication, attention must be paid above all to proper performance of the catheterization. Standardization disposable sets are helpful in this regard. Choice of the suitable catheter type depends on the requirements of the application, the duration of drainage and on the anatomical conditions. Use of a closed urine drainage system must be part of the clinical standard today as well as mastery of daily catheter hygiene. Under observation of the contraindications, advantage should be taken of suprapubic catheter drainage.

Catheterization↗

[Standardization of the testing of disinfectants in Europe].

Several European countries have adopted the evaluation of the microbicidal properties of disinfectants in two stages: after some preliminary tests, tests under practical conditions or main tests are carried out, as was described originally in the German guidelines for the testing of disinfectants. Nevertheless in the Anglosaxon countries, the use dilution of products intended for surface and floor disinfection is determined by suspension tests, capacity tests, or carrier tests. In some European countries, however, tests under practical conditions are developed for this purpose, but if these Belgian (B), German (D), French (F) and Dutch (NL) techniques are analysed and compared in their composing elements, great differences are found (Tables 1 to 3). Therefore the Belgian and Dutch tests must be the more severe. Another example of discordance is given in the preoperative disinfection of the surgeons' hand. Between 1973 and 1984 23 different testing techniques were described (Table 4). The differences in technique explain the differences in results obtained. In order to achieve a greater unification of the testing techniques, it is desirable to agree firstly on the requirements of disinfectants. Perhaps it is time to discuss it again.

Anti-Infective Agents, Local↗

The bactericidal activity of aqueous disinfectants applied on living tissues.

Thirteen antiseptic aqueous solutions intended for the disinfection of living tissues were compared in regard to their microbicidal effectiveness towards. Staphylococcus aureus and Pseudomonas aeruginosa. Six antiseptics, which contain boric acid, eosine, hydrogen peroxide or an organic mercury compound as the active substance, did not fulfil the requirements of the preliminary in vitro test. The seven other preparations were examined in a practical test, in which bactericidal activity was assessed on artificially contaminated intact skin after exposures of 15 s and 60 s. The most active solution appeared to be 0.5% tosylchloramide sodium, followed by 0.05% chlorhexidine with 0.5% cetrimide. The other preparations, namely 0.05% chlorhexidine without cetrimide, 0.245% chloroxylenol, 0.04% clorofene, 10% povidone-iodine and 0.2% tosylchloramide sodium, were less active in this practical test.

Bacteria↗

The choice of fungi as test organisms in disinfectant testing.

In order to find out whether more than one test organism is needed for the determination of the activity of disinfectants towards mycelium-forming fungi and yeasts, eight different species of fungi and one yeast-like fungus were submitted to seven different disinfectants in varying concentrations. As Candida albicans was found to be the most resistant, the authors propose that only Candida albicans should be used.

Bacteriological Techniques↗

Sterilization.

Explore the source record for details and available documents.

Cross Infection↗

A comparison of the quantitative suspension tests for the assessment of disinfectants.

The germicidal effect of two disinfectant standards has been determined by three quantitative suspension tests: the Dutch Standard-Suspension Test, the French AFNOR test, and the in vitro test. Particularly in case of Pseudomonas aeruginosa the germicidal-effect values found according to the three methods differ in a significant way (Tables 1 and 2). The only factors that could explain these differences, since they are not the same in the three techniques, are the preparation of the bacterial suspension and the diluent of the disinfectant solution. Through this the composition of the reaction mixture is different: in the in vitro test only 0.0085% NaC1 and 0.001% Tryptone are contained, in the AFNOR test the same constituants are ten times more concentrated and in the Standard-Suspension Test 0.882% NaC1 and 0.0306% albumin are present. If in the same trial these substances have been incorporated in the final concentration above-mentioned, then germicidal-effect values equal to those of the original tests have been obtained (Table 3). The disinfectant diluent and the bacterial suspension fluid have to be the main factors responsible for the differences in activity found by the three testing methods. In our opinion the in vitro test gives the clearest picture of the anti-bacterial properties of a disinfectant since in this test the less addition of extraneous matter is encountered.

Albumins↗

A collaborative study on a new quantitative suspension test, the in vitro test, for the evaluation of the bactericidal activity of chemical disinfectants.

In a collaborative study on a new quantitative suspension test for the evaluation of the bactericidal activity of chemical disinfectants, three laboratories performed the in vitro test on a phenol and an aldehyde standard in the critical use dilutions using Staphylococcus aureus and Pseudomonas aeruginosa as test organisms. The most striking finding was that the means of the germidical effect of one laboratory were significant lower than those of both others. Nevertheless the dispersion of the results did not differ among the laboratories. The differences could not be attributed to the subculture technique followed, nor to the daily inconstancy of the bacterial suspension resistance. The only feature that could explain the difference was the assessment of the microbiological work in itself. It should be stated, however, that the variance of the germicidal-effect values were rather low for this kind of microbiological work, so that differences between laboratories were significant even if the absolute values differed less than 1 unit.

Aldehydes↗

Efficacy of inactivators against 14 disinfectant substances.

More than 24 inactivators were tested for their suitability against 14 disinfectant substances by a quantitative suspension test. Even simple inactivators were found to be efficace: 0.1% cysteine and 0.5% sodium thiosulfate for mercuric chloride and the iodophor; 0.1% sodium sulfite for these two substances and for the QAC in the lower concentration; 1.0% polysorbate 80 for hexylresorcinol, o-phenylphenol and the QAC in the lower concentration; 0.5% sodium thioglycolate for mercuric chloride, the iodophor and chloramine-T. The inactivator active against most disinfectants was the combination LPHT or 0.3% lecithin / 3.0% polysorbate 80 /0.1% histidine / 0.5% sodium thiosulfate. Also active were: LPWT (0.5% lecithin / 1.0% polysorbate 80 /1.0% Lubrol W / 1.0% sodium thiosulfate), LPT (2.0% lecithin / 2.0% polysorbate 80 / 0.5% sodium thiosulfate) and PS (3.0% polysorbate 80 / 3.0% saponin).

Disinfectants↗

Bactericidal activity of 40 potential disinfectant inactivators.

Forty commonly used inactivators, both simple substances and mixtures, were tested by a quantitative suspension test for the property of being non-toxic to the bacterial cell. Some inactivators proved to be too inhibitory, even for undamaged organisms, namely cysteine in concentrations of 1.0% and higher, 0.3% and 2.0% lecithin (both especially for P. aeruginosa), and the mixtures 0.3% lecithin/2.0% polysorbate 80/0.1% histidine/2.0% turkey-oil red (for St. aureus) and 0.3% lecithin/3.0% polysorbate 80/0.4% sodium laurylsulfate (for both test organisms).

Bacteriolysis↗

Factors influencing the assessment of the pseudomonacidal activity of disinfectants by a quantitative suspension test. I. Influence of the growth conditions of the test organism.

A matter of special concern in disinfectant testing is the preparation of the bacterial suspension that shall be exposed to the action of the disinfectant. In the present paper attention is drawn to three details of the testing method being determinative for the resistivity of the test organism and for the degree of standardization of the test results. - In the first place the influence of the nutrient medium used in the cultivation of the test organism has been investigated. Sixteen culture media (Table 1) have been compared. The resistance of Pseudomonas aeruginosa to phenol depends on the formulation of the preparatory medium: significantly more bacteria survive if the test organism is grown on the nutrient agar following the German pharmacopoeia (Table 2). Further the author has investigated the effect of the temperature and the length of the initial culture incubation period (Tables 3 and 4). Here also the differences among temperatures (37, 32 and 22 degrees C) or incubation periods (48, 24 and 18 h) are statistically significant. The highest numbers of survivors are found when the initial culture is incubated at 37 degrees C and for 48 h. Whereas the resistance of the test culture is determined by these three factors, the variability of the test results is not. The coefficients of variation calculated for the different initial culture media, the three incubation temperatures or the three incubation periods show no differences among these test conditions.

Bacteriological Techniques↗

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↗