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PubMed2001

Micro-environment changes inside impermeable protective clothing during a continuous work exposure.

Protective clothing (PC) results in a micro-environment between itself and the body. Workers are then exposed to a heat stress greater than the ambient environment alone, which is a reflection of micro-environment, metabolic rate and time. Adjustments to the ambient environment to account for the micro-environment have been formulated as a means to predict heat strain for safety and productivity purposes. Measurement of the actual micro-environment was made for a mean of 63.1 +/- 7.9 min using a remote sensor at the shoulder, hip and thigh levels on 15 subjects during a continuous work protocol (300 kcal/h) in impermeable PC at an ambient temperature of 30.1 degrees C wet bulb globe temperature (WBGT) (32 degrees C dry, 29 degrees C wet, 33 degrees C globe). Micro-environment temperature increased over the duration of the work period. There was no statistically significant difference (p>0.05) between the measurements made at the three different body sites for temperature or humidity. The mean micro-environmental WBGT at the end of work was 34.6 degrees C WBGT. Micro-environment WBGT increased rapidly in the first 20 min of work then slowed, rising only 0.5 degrees C WBGT from 40 to 60 min. These results suggest that at this particular high ambient temperature (30.1 degrees C WBGT) an adjustment factor of 5 degrees C WBGT would give a more accurate indication of thermal stress for up to 1 h of continuous moderate work within PC. For shorter work durations, an even smaller adjustment would be appropriate.

Adult↗
PubMed2006

Fungal contamination in hospital environments.

OBJECTIVES: To assess the degree of fungal contamination in hospital environments and to evaluate the ability of air conditioning systems to reduce such contamination. METHODS: We monitored airborne microbial concentrations in various environments in 10 hospitals equipped with air conditioning. Sampling was performed with a portable Surface Air System impactor with replicate organism detection and counting plates containing a fungus-selective medium. The total fungal concentration was determined 72-120 hours after sampling. The genera most involved in infection were identified by macroscopic and microscopic observation. RESULTS: The mean concentration of airborne fungi in the set of environments examined was 19 +/- 19 colony-forming units (cfu) per cubic meter. Analysis of the fungal concentration in the different types of environments revealed different levels of contamination: the lowest mean values (12 +/- 14 cfu/m(3)) were recorded in operating theaters, and the highest (45 +/- 37 cfu/m(3)) were recorded in kitchens. Analyses revealed statistically significant differences between median values for the various environments. The fungal genus most commonly encountered was Penicillium, which, in kitchens, displayed the highest mean airborne concentration (8 +/- 2.4 cfu/m(3)). The percentage (35%) of Aspergillus documented in the wards was higher than that in any of the other environments monitored. CONCLUSIONS: The fungal concentrations recorded in the present study are comparable to those recorded in other studies conducted in hospital environments and are considerably lower than those seen in other indoor environments that are not air conditioned. These findings demonstrate the effectiveness of air-handling systems in reducing fungal contamination.

Air Conditioning↗
PubMed1995

Among-environment heteroscedasticity and genetic autocorrelation: implications for the study of phenotypic plasticity.

The impact of among-environment heteroscedasticity and genetic autocorrelation on the analysis of phenotypic plasticity is examined. Among-environment heteroscedasticity occurs when genotypic variances differ among environments. Genetic autocorrelation arises whenever the responses of a genotype to different environments are more or less similar than expected for observations randomly associated. In a multivariate analysis-of-variance model, three transformations of genotypic profiles (reaction norms), which apply to the residuals of the model while preserving the mean responses within environments, are derived. The transformations remove either among-environment heteroscedasticity, genetic autocorrelation or both. When both nuisances are not removed, statistical tests are corrected in a modified univariate approach using the sample covariance matrix of the genotypic profiles. Methods are illustrated on a Chlamydomonas reinhardtii data set. When heteroscedasticity was removed, the variance component associated with the genotype-by-environment interaction increased proportionally to the genotype variance component. As a result, the genetic correlation rg was altered. Genetic autocorrelation was responsible for statistical significance of the genotype-by-environment interaction and genotype main effects on raw data. When autocorrelation was removed, the ranking of genotypes according to their stability index dramatically changed. Evolutionary implications of our methods and results are discussed.

Genetic Variation↗
PubMed2000

Genotype-environment interaction for quantitative trait loci affecting life span in Drosophila melanogaster.

The nature of genetic variation for Drosophila longevity in a population of recombinant inbred lines was investigated by estimating quantitative genetic parameters and mapping quantitative trait loci (QTL) for adult life span in five environments: standard culture conditions, high and low temperature, and heat-shock and starvation stress. There was highly significant genetic variation for life span within each sex and environment. In the analysis of variance of life span pooled over sexes and environments, however, the significant genetic variation appeared in the genotype x sex and genotype x environment interaction terms. The genetic correlation of longevity across the sexes and environments was not significantly different from zero in these lines. We estimated map positions and effects of QTL affecting life span by linkage to highly polymorphic roo transposable element markers, using a multiple-trait composite interval mapping procedure. A minimum of 17 QTL were detected; all were sex and/or environment-specific. Ten of the QTL had sexually antagonistic or antagonistic pleiotropic effects in different environments. These data provide support for the pleiotropy theory of senescence and the hypothesis that variation for longevity might be maintained by opposing selection pressures in males and females and variable environments. Further work is necessary to assess the generality of these results, using different strains, to determine heterozygous effects and to map the life span QTL to the level of genetic loci.

Animals↗
PubMed2000

A chemometric approach to the estimation of the absorption spectra of dye probe merocyanine 540 in aqueous and phospholipid environments.

Merocyanine 540 (MC540) is a widely used dye probe for membranous environments. However, fundamental knowledge of the spectral features of this dye in aqueous and hydrophobic environments is still lacking. Such knowledge is important because biomembranes involve a hydrophobic environment surrounded by a hydrophilic environment. Because many investigations so far have been performed based on indistinct spectral estimations, the interpretation of the data obtained using this dye as a fluorescent transmembrane probe remains controversial. In order to determine the exact spectra in both aqueous and hydrophobic environments, we adopted principal factor analysis (PFA), a method of multivariate analysis. The PFA method can also determine the number of molecular species present in the reaction mixture, which is three in pure water and two in phospholipid suspension. Two of the species in both water and phospholipid suspension were the monomer and dimer. The third species in water was the trimer, but its amount was so small at 10 microM MC540 solution that the spectral data in water can be approximated neglecting this molecular species. The monomer spectrum changed its form markedly with a bathochromic shift when transferred from the water to phospholipid environment, whereas the dimer remained similar in its shape except for a remarkable red shift. In water, the dissociation constants, K(1) and K(2), for the assumed stacking-model reactions, M+M <--> M(2) and M+M(2) <--> M(3), were 3.1 x 10(-4) M and 5.7 x 10(-4) M, respectively. In the phospholipid environment, the dissociation constant K* for the assumed stacking-model reaction, M(*)+M(*) <--> *M(2), was 1.9x10(-5)M. The fluorescent intensities of MC540 were also measured in both water and phospholipid environments. A comparison based on the absorption and fluorescence spectra suggested that the temporal increase in the amount of the monomer on the excitable membrane contributes to the fluorescent intensity change observed in the transmembrane potential change.

Fluorescent Dyes↗
PubMed1996

A procedure for testing speech intelligibility in a virtual listening environment.

OBJECTIVE: The development of a test of virtual speech intelligibility in noise that enables assessment in typical, everyday listening situations. To eliminate extraneous confounding factors, digital signal processing was incorporated to simulate listening environments and source locations and allow presentation of stimuli via earphones. DESIGN: Source-to-eardrum transfer functions measured on KEMAR for various source locations in anechoic and reverberant environments were used to process monosyllabic words and speech-spectrum noise. Speech intelligibility was measured for three speech and noise configurations in two environments using an adaptive procedure to determine the signal-to-noise (S/N) ratio for 50% intelligibility. RESULTS: Normal-hearing listeners achieved 50% intelligibility of monosyllabic words at significantly lower S/N ratios in a virtual anechoic environment than in a virtual reverberant environment. Speech intelligibility improved significantly in both environments when the speech and noise sources were separated, but the intelligibility gain in the anechoic environment was four times larger than in the reverberant environment. CONCLUSIONS: This test is easy to administer and score, and it provides a means for measuring: 1) the effects of separating speech and noise sources and 2) the effects of reverberation on speech intelligibility in noise while eliminating confounding factors such as calibration.

Hearing↗
PubMed2001

Evolutionary adaptation to temperature. IX. Preadaptation to novel stressful environments of Escherichia coli adapted to high temperature.

Stressful environments may be considered as those that reduce fitness, sometimes due in part to the increased metabolic expenditure required to sustain life. Direct adaptation to a stressor is expected to increase fitness and reduce maintenance metabolism, with the latter leading to increased biomass production. In this study, we test the general hypothesis that such adaptation to one stressor can preadapt organisms to novel stressful environments. Six lines of Escherichia coli propagated for 2,000 generations at 41-42 degrees C (42 group), a stressful temperature, were compared to six control lines propagated for 2,000 generations at 37degrees C (37 group) and to the common ancestor of both groups. We assayed biovolume yield (a measure of growth efficiency) and competitive fitness in the 42 group's selective high temperature environment as well as five novel stressful environments-acid, alkali, ethanol, high osmolarity and peroxide. As previously reported, at high temperature the 42 group had both higher yield and fitness than the 37 group and ancestor. In the novel environments, the 42 group generally produced yields higher than the 37 group (and marginally higher than the ancestor), but we found no differences in competitive fitness among the 37 and 42 groups and the ancestor. We also found that the performance of lines within groups was not correlated across stressful environments for either yield or relative fitness. Because previous adaptation to one stressor did not improve our measure of Darwinian fitness in novel stressful environments, we conclude that the 42 group shows no useful pre-adaptation, or cross-tolerance, to these types of environments.

Adaptation, Physiological↗
PubMed1977

The environment and the microbial ecology of human skin.

Microbial flora of the skin of three human population groups representing different natural environments was examined quantitatively and qualitatively to determine whether environmental differences in temperature and humidity can influence the microbial flora of normal skin. Five anatomical skin sites - hands, back, axillae, groin, and feet - were sampled from 10 subjects working in a high-humidity, high-temperature environment, 10 subjects from a low-temperature, high-humidity environment, and 10 subjects working in a moderate-temperature and low-humidity environment. Bacterial populations were significantly larger from the back, axillae, and feet in individuals from the high-temperature and high-humidity environment as compared to the moderate-temperature, low-humidity environment. High humidity and low temperature had no significant effect on total populations, but this group showed a higher frequency of isolation of fungi, and gram-negative bacteria from the back and feet. Although there was an indication that increase in the environmental humidity could result in an increased frequency of isolation of gram-negative bacteria, there was no evidence that an increase in either temperature or humidity altered the relative proportions of gram-negative bacteria in the predominantly gram-positive microbial flora found on normal skin. It was concluded that, although climatic changes may cause fluctation in microbial populations from certain sites, they are not a major influence on the ecology of the microbial flora of normal skin in the natural environment. The variables introduced by studying individuals in their natural environment and the influence of these on the results are discussed.

Journal Article↗
PubMed1995

Characterization of Listeria monocytogenes isolated from poultry products and from the poultry-processing environment by random amplification of polymorphic DNA and multilocus enzyme electrophoresis.

A total of 289 Listeria monocytogenes strains isolated from a poultry-processing environment and poultry products over a 6-month period were characterized by random amplification of polymorphic DNA, (RAPD) to pinpoint sources of contamination within the plant and gain some measure of the persistence of individual genotypes within this environment. Eighteen RAPD profiles (A through R) were identified within this group, with 64% (184 of 289) of all strains displaying a single RAPD profile, RAPD type A. This genotype was more prevalent in the raw-poultry-processing environment, where, although its origin within this environment appeared to be the incoming birds, it was also widespread on food contact surfaces, floors, and drains. This was the only genotype which persisted throughout the entire 6-month period, and it and RAPD type B were the only two genotypes found in both the raw- and cooked-poultry-processing environments. L. monocytogenes strains isolated from cooked poultry products and the cooked-poultry-processing environment up to 1 year later (17 strains) contained only RAPD types A and B, highlighting the potential which exists for persistent strains to cross-contaminate foods processed in that environment. The other genotypes (C through R) occurred more sporadically, suggesting varied sources of contamination. These were confined to either the raw- or the cooked-poultry-processing environment and were relatively short-lived. Further characterization of a selection of RAPD type A strains, together with strains of RAPD types B through R, was carried out by multilocus enzyme electrophoresis. Strains of RAPD type A contained two electrophoretic types, one of which was serotype 1/2a and the other was 1/2c.(ABSTRACT TRUNCATED AT 250 WORDS)

Animals↗
PubMed1992

Interactive effects of thermal environment and dietary lysine and fat levels on rate, efficiency, and composition of growth of weanling pigs.

Two trials involving 96 weanling pigs were conducted in which pigs were maintained in constant thermal environments of 20 degrees (cool) or 32 degrees C (hot) and self-fed fortified corn-soybean meal-whey diets that contained three amino acid regimens (.7, 1.0, or 1.3% lysine; approximately 13.6, 17.8, and 22.0% CP) without and with 5% added fat (choice white grease) for 42 d. The pigs were weaned between 28 and 32 d of age (8.07 +/- .58 kg) and penned in groups of two. Pigs in the cool environment consumed more (P < .01) feed and ME, gained more (P < .01) weight, and retained more (P < .01) body protein, fat, and water than those housed in the hot environment. As dietary lysine level increased, daily BW gain and body protein and water accretion increased linearly (P < .01) from d 0 to 21 and quadratically (P < .01) from d 21 to 42 in both environments. However, the magnitude of these responses was less (P < .05) in the cool than in the hot environment. Dietary fat addition decreased (P < .05) gain:ME ratios and body protein and water accretion from d 0 to 21 in both environments, but the magnitude of the reduction was greatest in pigs fed the low lysine diets in the hot environment. Based on these data, the growth response of weanling pigs to dietary lysine and fat levels is dependent on the thermal environment in which the animals are housed.

Amino Acids↗
PubMed1992

Interactive effects of thermal environment and dietary amino acid and fat levels on rate and efficiency of growth of pigs housed in a conventional nursery.

In four trials, 480 weanling pigs were housed in a conventional nursery maintained at 20 or 30 degrees C, which represented a cool and hot thermal environment, respectively. They were allowed ad libitum access to corn-soybean meal-dried whey diets containing .7, 1.0, or 1.3% lysine and 0 or 5% added fat (choice white grease). The pigs were weaned between 27 and 33 d of age (7.27 +/- .90 kg) and penned in groups of five for the duration of the 42-d trials. Pigs housed in the cool environment consumed more feed (P < .01), gained more weight (P < .01), and utilized feed more efficiently (P < .01) than those in the hot environment. As dietary lysine levels were increased in the 20 and 30 degrees C environments, daily weight gains and gain:feed ratios increased linearly (P < .01) from d 0 to 21 and quadratically (P < .01) from d 21 to 42. However, the magnitudes of the increases were less in the cool environment, resulting in temperature x lysine interactions (P < .05). As the pig's feed intake, body weight, and heat production increased over time, the 20 and 30 degrees C environments became progressively warmer relative to the animal's zone of thermoneutrality. The associated reductions over time in energy and lysine intakes relative to the pigs' maintenance needs resulted in an increase in the concentration of dietary lysine needed to maximize rate and efficiency of gain in the 30 degrees C environment but not in the 20 degrees C environment (temperature x lysine x period interaction, P < .10).(ABSTRACT TRUNCATED AT 250 WORDS)

Amino Acids↗
PubMed2006

Weaning weight inheritance in environments classified by maternal body weight change.

In good environments, cow intake is sufficient for their own growth and for milk production to support their calf. In poor environments, cows lose BW or may reduce milk supply to maintain themselves. Heritability for direct genetic and maternal components of weaning weight as well as the correlations between these components might be expected to vary according to these circumstances. The purpose of this study was to estimate heritability and genetic correlations for the direct genetic and maternal components of weaning weight classified in 2 environments according to maternal BW gain and to identify whether a single heritability estimate is appropriate for the differing environments experienced by cows from year to year. Data used in this analysis was obtained from the Red Angus Association of America and consisted of 96,064 cow BW observations and 27,534 calf weaning weight observations. A dam's change in BW from one year to the next was used to classify each calf's weaning weight into 1 of 2 environmental groups, those being good or poor. Best linear unbiased estimates of the change in cow BW with age were obtained from analysis of cow BW using a repeatability model. If the phenotypic change in cow BW exceeded this average BW change, the calf's weaning weight associated with the end of this time frame was classified as having been observed in a good environment. If not, the calf's corresponding weaning weight was classified as having occurred in a poorer than average environment. Heritability estimates of 0.24 +/- 0.03, 0.24 +/- 0.03, 0.13 +/- 0.02, and 0.14 +/- 0.02 were obtained for weaning weight good direct, poor direct, good maternal, and poor maternal, respectively. Correlations between direct genetic and maternal weaning weight components in the good and poor environments were -0.47 +/- 0.08 and -0.20 +/- 0.09, respectively. These variance components are not sufficiently distinct to warrant accounting for dam nutritional environment in national cattle evaluation.

Aging↗
PubMed2001

Work environment of Danish shift and day workers.

OBJECTIVES: Both shift work and other work environment factors have been shown to be related to heart disease. This study examined whether shift work is associated with other work environment factors related to heart disease in a random sample of the population. If so, shift work could be acting as a proxy for work environment differences. METHODS: Data on 5940 employees in the Danish Work Environment Cohort Study from 1990 were reanalyzed. The information included work schedules [permanent day work, irregular workhours (including morning work), 2-shift or fixed evening and 3-shift or fixed night], length of workweek, physical factors (noise, heat, dust, passive smoking, walking, standing and monotonous repetitive tasks), and psychosocial factors (including demands and control dimensions, social support, conflicts and job insecurity). RESULTS: At least 1 group of shift workers had a higher prevalence of nearly every unfavorable work environment factor investigated. Exceptions were dust exposure and quantitative demands. Especially conflicts at work and low decision latitude were higher among all the groups of shift workers, and all-day walking or standing work and part-time jobs were more often found among female shift workers. The 3 different shiftwork groups were exposed to different parts of the work environment, and also men and women in shift work differed in relation to the work environment. Age and social class influenced the relationship, but not in any particular pattern. CONCLUSIONS: In a heterogenous population shift work was found to be associated with other work environment factors suspected to cause heart disease.

Adolescent↗
PubMed2006

The effect of training of military skills on performance in cold environment.

This study was conducted to evaluate how training for disassembling and assembling a weapon and patrol data message terminal and loading a magazine in different temperatures affected the ability to perform those skills in a cold environment. One group trained six times on separate days in a warm environment (19 degrees C), the second group trained three times in a warm environment and then three times in a cold environment (-15 degrees C), and the third group trained six times in the cold environment. Training first in warm and then in cold shortened performance time by 6% to 28%, in comparison to training only in a warm environment. Also, training in cold made the subjects faster than training in warm. In conclusion, before performing military operations in a cold environment, it is most beneficial to train first in warm and then in cold. Training only in warm produces the lowest level of performance in a cold environment.

Adaptation, Physiological↗
PubMed1999

Floral plasticity in an iteroparous plant: the interactive effects of genotype, environment, and ontogeny in Campanula rapunculoides (Campanulaceae).

Phenotypic variation in 11 floral and reproductive traits was studied in cloned plants of Campanula rapunculoides replicated in three discrete environments. Using an ANOVA approach, we determined the relative influence of genotype (G), environment (E), G × E interaction, and ontogeny (position on the raceme) on the 11 traits. Two traits, duration of flowering and pollen size, showed no significant variation. All nine remaining traits had significant genotypic variation, accounting for 21-38% of the total phenotypic variation. Correlations among variant traits in seven genotypes were predominantly positive, but several significant correlations in one environment changed sign or were nonsignificant in another environment. Ovule number was negatively correlated with most male function traits: the negative correlation between ovule and pollen number was particularly strong and consistent across environments. Six traits varied significantly across environments, including number of flowers, number of ovules per flower, and duration of the male phase, but pollen traits did not show a significant environmental main effect. The G × E interaction was significant for flower number, corolla size, nectar quality, duration of the male phase, pollen viability, and ovule number. The contribution of interaction variance to the total phenotypic variation (5-14%) was comparable to that of the environment alone (7-21%). Ovule number decreased in flowers on the upper part of the raceme by nearly 25%, but other traits did not vary significantly by floral position. These results suggest that (1) pollen traits are buffered against environmental change more than ovule number or other floral characters, (2) a male-female trade-off exists and is complicated by ontogenic factors, (3) G × E interactions are common but may have small effects, and (4) specific correlation patterns among floral traits can be dependent upon the environment under which they develop.

Journal Article↗
PubMed1999

International standards for the assessment of the risk of thermal strain on clothed workers in hot environments.

The International Standards Organisation (ISO) has produced an integrated series of international standards for the assessment of human responses to thermal environments. They include standards for the assessment of thermal comfort, heat stress and cold stress and many have been adopted as European and British standards. This paper describes the series of standards and in particular those concerned with the assessment of risk in hot environments. A three tier approach is taken which involves a simple thermal index that can be used for monitoring and control of hot environments (ISO 7243), a rational approach which involves an analysis of the heat exchange between a worker and his or her environment (ISO 7933) and a standard that describes the principles of physiological measurement which can be used in the establishment of personal monitoring systems of workers exposed to hot environments (ISO 9886). The standards are self-contained and can be used independently. In any comprehensive assessment however they would be used in conjunction. The simple index provides a first stage analysis and can confirm whether or not there is likely to be unacceptable thermal strain. Where a more detailed analysis is required then ISO 7933 provides an analytical method that can provide a more extensive assessment and interpretation leading to recommendations for improvement to the working environment. Where a method needs to be confirmed, or conditions are beyond the scope of ISO 7243 and ISO 7933, then ISO 9886 provides guidance on physiological measurement and interpretation. This would be used in extreme environments where individual responses are required to ensure health and safety or, in the case where personal protective equipment (PPE) is worn, which is beyond the scope of ISO 7243 and ISO 7933. The ISO system therefore covers almost all exposures to hot environments. It would be useful however to extend the scope of the standards that provide a simple index or analytical approach. This paper describes the current standards and their scope and forms the basis and background for descriptions of proposed extensions to the scope of the standards described in other papers in this special issue.

Acclimatization↗
PubMed2002

Comparison of static and dynamic medium environments for culturing of pre-implantation mouse embryos.

The ability to manipulate mouse pre-implantation embryos in vitro has become a valuable tool in many scientific disciplines. However, fewer embryos maintain viability following in vitro manipulation compared with embryos in vivo. It has been suggested that use of dynamic medium environments may improve viability by simulating in utero environment. The objective of the study reported here was to compare a microdrop in vitro culture system with a microdevice in vitro culture system containing a static and two dynamic medium environments (0.1 and 0.5 microl/h) for culturing of mouse pre-implantation embryos. Results indicated that the static medium environment, in silicon-glass microdevices, was not significantly different from the microdrop control environment in proportion of embryos developing from the two-cell to the blastocyst stage. However, the static microdevice environment produced significantly (P < 0.05) more morulas than did that of the control group. Both of these treatment groups, under the presented conditions, consistently had significantly higher proportions of blastocysts (P < 0.05) and morulas (P < 0.05) and lower proportions of abnormal (P < 0.05) and eight-cell embryos (P < 0.05), compared with those of the high flow rate dynamic environment microdevice treatment groups. Studies exploring slower or pulsatile rates of medium delivery in a dynamic medium environment are indicated.

Animals↗
PubMed2002

[Effect of care in a protected environment on the occurrence of nosocomial infections, mucosal colonization of pathogenic microflora and development of indicators of immunity in premature infants].

OBJECTIVE: Prevention of hospital infections in premature infants by treatment in protected environment and intentional colonization of the intestine by oral administration of non-enteropathogenic E. coli. DESIGN: Original article. SETTING: Institute for Care of Mother and Child, Prague. METHODS: Fifty premature infants were followed at the Intensive Care Unit. Twenty five infants were treated after birth in protected environment and colonized during the first 48 hours by oral administration of a apathogenic E. coli strain (Vaccine COLINFANT, registered and produced in the Czech Republic), 25 infants were treated in conventional environment. Bacteriological examinations: stool, nose, throat, ear, stomach end other smears were taken 2-3 times during first week and further once a week and examined by aerobic cultivation. Immunological examinations: globulin levels (IgG, IgM) were estimated in blood samples by ELISA, using specific polyclonal antibodies. As early marker of infection T and B subpopulations were measured by FACS analysis using double labelling of cells. RESULTS: Birth weight, birth length, gestational age, Apgar score, were relatively equal in both groups. Time of hospitalization was 7.3 days shorter in infants treated in protected environment. Colonization with pathogens (130), number of infections (16%) and need for antibiotics (16%) were significantly lower in infants treated in protected environment than in infants treated in the conventional one (238 isolated pathogens, nosocomial infections in 40%, need for antibiotical treatment in 48% if infants). Serum IgM levels were lower in infants treated in protected environment other immunological parameters did not differ in the two groups. CONCLUSION: Treatment of premature and high-risk infants in protected, pathogen-free environment and intentional colonization with apathogenic E. coli reduced significantly the number of isolated pathogens, number of hospital infections, need for antibiotics and shortened the time of hospitalization in comparison with infants treated in conventional environment.

Administration, Oral↗