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At least 19 recordsLinked to original sources
PubMed1979

[On the contamination of the citric acid fermentation. I. The contamination by representatives of Enterobacteriaceae (author's transl)].

Among the most dangerous bacterial contaminations of the citric acid fermentation is the so-called brown contamination, which is called forth by non pathogenic representatives of Enterobacteriaceae like Escherichia coli, Aerobacter aerogenes, Enterobacter cloacae and Proteus vulgaris, while other bacteria do not produce the mentioned contamination. There is given a comprehensive characterization of the brown contamination. Enterobacteriaceae interrupt the growth of the mycelium of the mold Aspergillus niger and stop the production of citric acid, produce a characteristic repugnant smell and reduce nitrate to nitrite. In a case of weak contamination the phenomena of the brown contamination do not appear, but the yield of citric acid is rather low. The contamination may be transferred successfully within the first 24 hrs. of incubation. The effect of the bacteria is determined by their virulence and some other factors.

Aspergillus niger↗
PubMed1978

Bacterial contamination in a modern operating suite. 4. Bacterial contamination of clothes worn in the suite.

Clean clothes in the staff dressing rooms were heavily contaminated with bacteria, mainly Bacillus sp., but Staphylococcus aureus were found on 14% and Clostridium sp. on 10% of the garments examined. A comparison of the occurrence of Staph. aureus on shirts worn by staff in wards and operating departments showed ward shirts to be contaminated more heavily and with more strains. Examination of sterile gowns worn by surgeons showed that 70% were contaminated with Staph. aureus after operation. Of the strains isolated 31% were identical with those carried by the surgeon or by the patient operated on, but for the remainder no source could be found.

Bacillus↗
PubMed2026

Leveraging environmental applications and risks of coal gangue: A critical review on authigenic inorganic heavy metals, organic contaminants, and the removal of exogenetic contaminants.

Coal gangue (CG) as bulk solid waste has seriously threatened the ecosystem. Therefore, identifying the key risk drivers and exploring feasible disposal methods for CG are essential for developing a sustainable strategy. However, there is currently a lack of comprehensive information that balances the contamination risks with the valuable constituents present in CG, which hinders its full potential for sustainable use without negative environmental impacts. Given the complex composition and associated risks, we propose that addressing the critical properties related to contamination is crucial for the efficient utilization of CG. On this premise, we summarized several practical resource pathways (ecological multifunctional materials, extraction of rare elements, and soil additives) that are more favorable for sustainable development relative to conventional disposals. Meanwhile, we also propose that coupling disposals could intensely reduce CG's environmental footprints and capital costs. Consequently, regardless of the number of challenges to be solved, we believe the CG has broad application prospects, and we hope this review will promote the conversion of CG into an asset with lower ecological and social impacts.

Metals, Heavy↗
PubMed1978

Bacterial contamination in a modern operating suite, 2. Effect of a zoning system on contamination of floors and other surfaces.

In this investigation the bacterial contamination of surfaces such as walls and floors in a modern operating suite, together with surfaces of lamps in the operating theatres, and the clogs worn by staff, was studied. Counts of colony-forming units were made on impression plates containing blood-agar with Tween 80 for total bacterial counts, Baird Parker medium with egg yolk and tellurite for Staphylococcus aureus and trypticase peptone agar with neomycin and polymyxin for Clostridium spp. The areas examined were divided into the patients' route to the operating theatre, the staff's route, and the central area containing the operating rooms, anaesthetic rooms, and exit and scrub-up areas. In the patients' route counts of total organisms ranged from about 10000 to 30000/m2; for Staph. aureus the range was from 70 to 540/m2. In the staff's route the highest count was about 70000/m2 in the dressing area, and the numbers of Staph. aureus were about the same as along the patients' route. In the inner zone the counts were somewhat lower for both total organisms and Staph. aureus. Total counts on the floor from all areas of the inner zone were significantly higher just before the second operation than before the first operation on the same day. The total and Staph. aureus counts on walls, floors and lamps were the same after clean operations as after operations classified as "contaminated" or "dirty".

Air Microbiology↗
PubMed1979

Accidental contamination of diagnostic cultures of mycobacteria and phage identification of the contaminating strain.

Phage typing of mycobacteria is a new technique not yet widely used for classification and intraspecies differentiation. Systematic long-term studies organized by the WHO have succeeded, using a battery of 11 different mycobacterial phages, in dividing M. tuberculosis into 3 different phage sub-groups, preliminarily labelled as A, B and C. A special case of phage-typing is presented which enabled identification of a virulent mycobacterial strain causing accidental contamination of diagnostic mycobacterial cultures. The strain was an old laboratory one, H37Rv, belonging to phage subgroup B.

Bacteriophage Typing↗
PubMed1978

Bacterial contamination in a modern operating suite. 3. Importance of floor contamination as a source of airborne bacteria.

The redispersal factor for bacteria-carrying particles from a contaminated floor was determined after mopping, blowing and walking activity. Walking gave the highest redispersal factor, 3.5 X 10(-3) m-1, which was three times higher than for blowing and 17 times higher than for mopping. The mean die-away rate for the bacteria-carrying particles used was 1.9/h without ventilation and 14.3/h with ventilation. It was calculated that in the operating rooms less than 15% of the bacteria found in the air were redispersed floor bacteria.

Air Microbiology↗
PubMed1975

Ecological observation of the 137Cs-contamination in beef of animals from the southern-Bavarian area.

Certain climatic and edaphic conformations in the Bavarian sub-alpine mountains and in the Alps favor above all the development of a land utilization system and farm structures similar to those in the northern part of Scandinavia. In 1963/64, the years of the highest environmental contamination up to the present, we established in 600 beef samples from the round or shoulder of male and female cattle (mainly Highland cattle) close connections between the 137Cs-contamination of green crop and the long lastnig yearly precipitation quantities, as well as certain relations between the 137Cs-contamination of meat and differences in the feeding and keeping of the animals. During summer-seasons (April-October), beef of cattle from pastures with heavy rainfall (Alps) was contaiminated by 137Cs up to 15 times more than that of confined animals. Hereby the rate of 137Cs-contamination in the meat of grazing cattle was nearly proportional to the quantities of precipitation. When confined cattle were fed on pastures in autumn after harvesting for 2 to 3 weeks, a quick increase of 137Cs-contamination of the meat was caused within this time up to values which in this district were otherwise only observed in grazing cattle. The lower 137Cs-content in meat of cattle housed during the summer season is due to the more varied fodder, which is at that time less contaminated than green crop. During the winter season (November to March), the highest contaminations in the meat of confined (Bohemian Forest) or grazing cattle (Alps) was measured when the animals in these districts were almost exclusively fed with fodder from the own farmground or with leafy silage. The highest contamination was almost regularly noticed in January, February and March, as generally during these months the highly contaminated first cut hay is fed. Here the meat was often even more contaminated than that of grazing cattle. After the quick decrease of 137Cs in fallout noticed in the years 1964 and 1965, in 1965/66 a dependance in the 137Cs-contamination of beef on the methods of keeping and feeding could still be observed in only the extreme cases (Alps, Bavarian- and Bohemian Forest); though in general, meat of animals from districts with heavy rainfall was slightly more contaminated than meat of animals from regions with less precipitation.

Animals↗
PubMed1979

Adventitious contamination of intravenous admixtures during sterility testing.

The extent to which contamination of intravenous fluids measured by inhospital sterility-testing may be due to adventitious contamination (i.e., contamination introduced during the sterility-testing procedure) was studied. All one-liter admixtures prepared during a three-day period in a busy centralized i.v. admixture service were studied. Samples of i.v. admixtures were cultured before and after administration by direct ioculation or by culturing the membrane through which the admixture was filtered. Samples of similarly cultured large-volume parenterals served as controls. Contamination rates for control and admixture samples were not significantly different (p = 0.23). Of 10 control and test (admixture) solutions showing contamination before administration, only one test solution again showed contamination after administration but this was with a different microbe. The results suggest that adventitious contamination during sampling/culturing procedures is a component of, and possibly a dominant factor in, the contamination rates detected by inhospital sterility tests. Combined with infection surveillance, sterility tests may be of value when infections are possibly related to admixture contamination.

Bacteria↗
PubMedDate not supplied

Relationship between length of time and contamination in open intravenous solutions.

This study investigated rate of contamination in simulated in-use intravenous solutions to obtain data from which to recommend a standard time period for the administration of intravenous solutions. Although the Center for Disease Control and many medical institutions have recommended that all bottles of in-use intravenous solutions be changed every 24 hours, there are no published data to support the 24-hour standard. In this study, samples were drawn from 80 bottles of Ringer's Lactate solution at predetermined time intervals over 48 hours and cultured on blood agar plates to determine rate of contamination. A low incidence of intravenous solution contamination was found at all time periods. Of 430 total samples, only 12 (2.8%) were contaminated. Results of this study did not indicate a significant relationship between time and contamination of simulated in-use intravenous solutions. Therefore, contamination that does occur within 48 hours in intravenous solutions must be introduced from some exogenous source. Further research is required to elucidate exogenous sources of contamination. In the meantime, it can be concluded, the 24-hour standard is adequate to protect against contamination that would occur solely from preparation of the intravenous solution for administration.

Drug Contamination↗
PubMed2024

Contaminant-degrading bacteria are super carriers of antibiotic resistance genes in municipal landfills: A metagenomics-based study.

Municipal landfills are hotspot sources of antimicrobial resistance (AMR) and are also important habitats of contaminant-degrading bacteria. However, high diversity of antibiotic resistance genes (ARGs) in landfills hinders assessing AMR risks in the affected environment. More concerned, whether there is co-selection or enrichment of antibiotic-resistant bacteria and contaminant-degrading bacteria in these extremely polluted environments is far less understood. Here, we collected metagenomic datasets of 32 raw leachate and 45 solid waste samples in 22 municipal landfills of China. The antibiotic resistome, antibiotic-resistant bacteria and contaminant-degrading bacteria were explored, and were then compared with other environmental types. Results showed that the antibiotic resistome in landfills contained 1,403 ARG subtypes, with the total abundance over the levels in natural environments and reaching the levels in human feces and sewage. Therein, 49 subtypes were listed as top priority ARGs for future surveillance based on the criteria of enrichment in landfills, mobilizable and present in pathogens. By comparing to those in less contaminated river environments, we elucidated an enrichment of antibiotic-resistant bacteria with contaminant-degrading potentials in landfills. Bacteria in Pseudomonadaceae, Moraxellaceae, Xanthomonadaceae and Enterobacteriaceae deserved the most concerns since 72.2 % of ARG hosts were classified to them. Klebsiella pneumoniae, Acinetobacter nosocomialis and Escherichia coli were abundant multidrug-resistant pathogenic species in raw leachate (∼10.2 % of total microbiomes), but they rarely carried contaminant-degradation genes. Notably, several bacterial genera belonging to Pseudomonadaceae had the most antibiotic-resistant, pathogenic, and contaminant-degrading potentials than other bacteria. Overall, the findings highlight environmental selection for contaminant-degrading antibiotic-resistant pathogens, and provide significant insights into AMR risks in municipal landfills.

Metagenomics↗
PubMed1976

Wound infections in clean and potentially contaminated surgery. Importance of bacterial and non-bacterial factors.

Postoperative wound infections in clean--and potentially contaminated surgery were studied with regard to demonstrable wound contamination and the occurrence of non-bacterial wound infection promoting factors. The incidence of demonstrable wound contamination in clean surgery was low, and observed rates of wound infection could not be related to differences in wound contamination, but to the occurrence of non-bacterial wound infection potentiating factors, e.g. implantation of foreign materials (osteosynthesis), cicatrical tissues or a compromized host. Corresponding studies in potentially contaminated surgery revealed a significantly higher incidence of wound contamination compared to clean surgery and a significant correlation between Gram negative wound contamination and rates of postoperative wound infections in certain types of gastrointestinal surgery. Patient factors, such as age or malignancy, did not influence the wound infection frequency when the incidence of wound contamination was taken into consideration.

Adolescent↗
PubMed1978

Autotransfusion of contaminated intraperitoneal blood: an experimental study.

Contamination of blood by bowel contents has been generally assumed as an absolute contraindication to autotransfusion. Since abdominal trauma is frequently accompanied by bowel injury and massive blood loss, a potential major use for autotransfusion has thus been precluded. To test this presumption, autologous blood grossly contaminated with feces was incubated in the peritoneal cavity and then autotransfused in dogs. The animals were hemorrhaged 20, 30, or 40% of their estimated blood volume, producing mild to severe hypovolemic shock. Reinfusion of contaminated blood had little effect on survival with 20 or 30% hemorrhage, but contamination markedly decreased survival with 40% hemorrhage:90% survived without contamination while only 30% survived with contamination. The use of antibiotics in a similar group of dogs subjected to 40% hemorrhage essentially eliminated the risk of autotransfusion: 90% of these dogs survived autotransfusion of contaminated blood.

Animals↗
PubMed1979

Herbicide contamination and decontamination of well waters in Ontario, Canada, 1969-78.

OVER THE 10-YEAR period 1969-78, the waters of 237 wells were analyzed because of contamination from herbicide spillage in or near the well, complaints of impaired water flavor, or injury to seedling plants moistened with the well water. Herbicides were identified in 159 wells: 98 had a single herbicide, 46 had two, 12 had three, one had four, and another had five separate herbicides contributing to the contamination. Wells were grouped according to the mode of entry of the contaminant. Entry occurred most commonly as an aerial spray fdrift or in runoff. Serious contaminations were caused by spillage of herbicide concentrates and spray solutions in or around the well. Twenty-four of the contaminated wells were further investigated to determine the persistence of the contaminant and how to remove it. Some wells were decontaminated adequately to allow reuse within nine weeks, others required three years, and yet others had to be abandoned. Particularly persistent contaminants were amitrole, dinoseb, and picloram.

Herbicides↗
PubMed1975

Environmental and food contamination with PCB's in Japan.

In Japan "yusho", i.e., poisoning caused by ingestion of rice oil contaminated with PCB's, broke out in October 1968, and produced more than 1200 officially certified cases. Nevertheless, it was only regarded as a kind of food poisoning and its connection with environmental and biological contamination was only imperfectly taken into consideration. Finally, in the autumn of 1970, two study groups, from the Ehime University and the Kyoto City Hygienic Institute, reported on the PCB contamination of salt water and fresh water fishes in Japan. Subsequently many reports about PCB's as an environmental contaminant have been published by several study groups throughout Japan, and nowadays the PCB polluted state of Japan has become rather clearly recognized. This report will present information on environmental, food and human contamination with PCB's in Japan especially also in some typically contaminated local areas, in addition to summarizing some overall aspects of the PCB problem in Japan (e.g., the production, shipment and use of PCB's).

Adipose Tissue↗