Zentralblatt fur Bakteriologie. 1. Abt. Originale B, Hygiene, Krankenhaushygiene, Betriebshygiene, praventive Medizin最新文献

1. Analyses made at a bath with an additional ozone processing stage showed that the bathers caused a marked bacterial contaminatin on busy days and that this contamination did not originate from the purification plant. 2. This finding and numerous individual analyses of water from various swimming pools yielded a spectrum of 14 micro-organisms, 4 genera being of frequent incidence: bacillus, staphylococcus, pseudomonas and flavobacterium. In general, bacterial contamination exists not only in the pool itself but also after filtering and even subsequent to the addition of chlorine. Staphylococci were found to be particularly invulnerable even to high chlorine contents, which is likely to be attributable to their enclosure in organic material. 5. Tenfold sampling demonstrated that the identification of Staphylococcus aureus in individual samples is unreliable despite its ubiquitous occurrence, probably due to their uneven distribution in the water, while the identification or exclusion of Pseudomonas aeruginosa proves sufficiently dependable even with only individual samples. 4. The general routine analysis of swimming pool water for the presence of staphylococcus aureus appears not justifiable, whilst testing for Pseudomonas aeruginosa appears justifiable, especially for identifying potentially dangerous filter contaminations.

After ethylene oxide sterilization unwanted side effects are possible if the sterilized materials are not aerated sufficiently. The desorption of ethylene oxide depends upon many factors. Some of these are the composition of the sterilized materials and the various aeration provisions. It is nearly impossible to make general aeration recommendations because almost each item has different characteristics in regard to the absorption and desorption of ethylene oxide. We investigated the ethylene oxide residues in endotracheal tubes, nasal and oropharyngeal airways of various manufacturers as well as breathing tubes and bags of the Rüsch Company. For sterilization we used two DMB STERIVIT high pressure sterilizers, one Webeco ATOMAT 18, one Webeco ATOMAT 170 and one STERI-VAC 400 B Sterilizer of the 3 M Deutschland Company which operated under a low pressure system. For determination of the residues wer performed a total of about 1000 gaschromatographic analyses. The materials were aerated for 7-10 days at room temperature of 22 to 25 degrees C. IOn addition we perfused children PVC endotracheal tubes with 3 liter/min N2O/O2. By this considerable higher amounts of ethylene oxide were released than in quiet room air. The following recommendations can be made: Portex Blue Line and Rüsch Rüschelit acult tubes should aerate for 10 days. For Portex Blue Line children tubes a shorter time will be sufficient. Portex "green"PVC and Rüsch red rubber tubes retained less ethylene oxide than Blue Line and Rüschelit tubes. Portex oral airways must be vented for 10 days. Rüsch breathing tubes and bags can be used after 48 hours. The recommended aeration time must be observed precisely. Modern heated aerators with continuous air exchange accelerate the degassing process considerably.

The aim of this investigation was to develop a mathematical model of mean age, mean arsenic dietary dose, and age-specific prevalence rate for endemic chronic arsenic poisoning. Data on mean age (years), mean arsenic dietary dose (mg/kg body weight/day), and age-specific prevalence rate per 100,000 population for endemic chronic arsenic poisoning in Antofagasta Commune, northern Chile, for the 1968-1971 period, were collected. Endemic chronic arsenic poisoning means here chronic arsenical dermatosis associated with marked or sever symptoms (or signs) of chronic arsenic poisoning (chronic diarrhoea, hepatic cirrohsis, chronic bronchitis, bronchiectasis, recurrent broncho-pneumonia, cardiomegaly, systemic occlusive arterial disease, cerebral thrombosis, etc.) There was a strong positive correlation between age-specific prevalence rate per 100,000 population and mean arsenic dose (r = + 0.9593) and a negative correlation between prevalence rate and mean age (r = 0.8789). These findings show that the prevalence rate declines with the advancing age and increases with the increase of arsenic dose. A multiple linear regression model E(y) = alpha + beta X1 + gamma X2, where y represents the age-specific prevalence rate per 100,000 population, X1 the mean arsenic dose, and X2 the mean age, was fitted to the data. The estimates of the parameters (alpha, beta, and gamma) were obtained by minimizing the residual sum of squares sigma(y - alpha - beta X1 - gamma X2)2. The following multiple linear regression equation was obtained: Y = 202.161 + 8452.455 X1 - 2.394 X2. Of the total variability in the prevalence rate, 96.22 per cent was accounted for by the multiple regression.

Residues of ethylene oxide and chemical disinfectants in anesthesia supplies can cause side effects in patients. For this reason we intubated 37 New Zealand rabbits with PVC endotracheal tubes of 3.0-3.5 mm inner diameter. The tubes were sterilized with ethylene oxide and aerated for 24 or 48 h in room air. At this time they still held 600 resp. 80 ppm ethylene oxide as we had determined by gaschromatography. For comparison tubes were soaked in 2% activated Cidex or 10% Gigasept and watered for 1 h in sterile water. 5 not intubated animals served as controls. All rabbits were sacrificed after 48 h and larynx and trachea examined microscopically for histological changes. In all intubated animals we found hyperemia, edema formation and cellular infiltration. In addition there were epithelial erosions in about 60% and 4 uclers. The findings were considerably more pronounced in animals which had been intubated with tubes containing 600 ppm ethylene oxide. Almost all tubes cause mechanical irritation of the respiratory tract. Additional chemical trauma is not to be expected, however, if they are watered adequately after treatment with disinfecting solutions resp. aerated sufficiently after ethylene oxide sterilization.

A physiotherapeutical indoor swimmingpool in a hospital was inspected for the presence of potentially pathogenic Limax-amoebae. In cultures inoculated with material from water samples and from cotton swabs taken from the bottom and walls of the pool the following species of Limax-amoebae could be cloned and identified: Naegleria gruberi, Hartmannella vermiformis, Acanthamoeba castellamii, A. polyphaga, A. palestinesis, Vannella mira, V. platypodia, Platyamoeba stenopodia, Echinamoebia exundans and Vexillifera bacilipedes. Two further strains of unidentified Acanthamoeba and 1 of the genus Vanella were observed. 3 to 5 species remained unidentified. Beyond this numerous monotrichous flagellates and Colpoda steini, a holotrichous ciliate, multiplied in water samples and agar plates. The concentration of the total number of pelagic amoebae increased from 10 to 20/liter one week after exchange of the pool-water to 100-1000/liter after 3 weeks and finally to more than 10(4) per liter after a period of 2 months. The isolated strains of Nageleria, Acanthamoeba and Hartmannella were tested for pathogenicity by means of the intranasal mice inoculation test. The clones of Naegleria were submitted to a temperature- and salt-tolerance test. All of the strains tested by these methods proved to be nonpathogenic.

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.

Defined number of S. Senftenberg W 775 (between 300 000 and 16 000 000 colony forming units in relation to 1 ml of the ready-to-serve-product) were added to 21 different dehydrated ready-to-eat-meals (no baby and junior food) cutomary in trade, of which 11 were cooked for a certain period of time, while 10 were prepared with boiling water only. No surviving salmonellae were found in any of the products ready for consumption. All samples were subject to temperature control. In this paper 6 examples are given to show temperature control during the phase of preparation. More than 1800 examinations performed by us on comparable products revealed no salmonellae in samples between 20 and 50 g. However, in view of the ubiquity of salmonaellae today, incidental positive findings in dehydrated products of this type cannot be excluded; but such findings would not defintely mean degredation of the product. If properly prepared, the food concerned is not dangerous to the consumer.

This experiment was designed to study the degree of recovery from lead-induced neuro-behavioral deficit after normalization of blood lead-level (PbB). Female Wistar-rats were given a diet containing lead-acetate (2260 ppm Pb) for 60 d until mating, giving rise to a PbB-increase from 53 microgram/d1 (before mating) to 84 microgram/d1 (after weaning). Lead-exposure of their male offspring was continued for 4 months with their PbB levelling off at 40 microgram/d1 (table 1). Lead-feeding was discontinued thereafter for another 4 months, PbB declining to a final level of 12 microgram/d1 (table 1). These animals were then compared for neurobehavioral functions to age-matched controls with respect to discrimination-learning (Lashley jumping-stand) and motor activity (open field-test). In addition recovery from initial loss of body-weight after partial food-deprivation was measured, known to be retarded at elevated PbB. The results may be summarized as follows: Formerly Pb-treated animals subsequently raised on a lead-free diet resulting in PbB-normalization within 4 months as compared to untreated controls exhibit (1) significant retardation of recovery from initial loss of body-weight (fig 4), (2) significant increase of error-repetitions in discrimination-learning (table 4; fig. 5) indicating disturbances of learning-performance without a change in learning-speed, and (3) significant hypoactivity (ambulation) without a significant change of other variables of open field-behavior (table 5; fig. 6). These results demonstrate, that some neurobehavioral and systemic symptoms of Pb-related dysfunction persist even after normalization of PbB, thus indicating partial irreversibility of Pb-induced damage.