Assessment of the content of macronutrients and microbiological safety of dry dog foods.

In Europe, there are no legal regulations specifying maximum allowable limits for pathogenic bacteria or fungi and yeasts in dog food. For proximate composition, the European Pet Food Industry Federation (FEDIAF) nutritional guidelines provide minimum recommended levels for protein and fat only, not for other ingredients and no safe maximum levels. Therefore, the aim of this study was to evaluate the microbiological safety of 35 dry dog foods, taking into account the division into foods with grains as the main plant ingredient and those described as grain-free. We assumed that grain-included foods are more susceptible to the presence of the total number of aerobic bacteria. This parameter is an essential, hygienic criterion informing about the microbiological safety of the pet food. It also inform about the microbiological quality of the food ingredients used, the effectiveness of decontamination during the production process, sanitary and hygienic conditions during the acquisition, processing and marketing of pet food and its components. In the case of macronutrients, the results in some cases were multiples of the minimum recommended levels. The most important microorganisms that presence was found in the analyzed dog foods were indicator bacteria (E. coli and coliform bacteria, Clostridium perfringens), whose presence in feed constitutes microbiological contamination. They inform about sanitary and hygienic conditions during the production and storage of the pet food. The current guidelines recommend microbiological testing of food for the presence of Salmonella bacilli as the basic indicator for assessing the sanitary quality. No Salmonella spp. was detected in any of the foods. The remaining analyzed bacteria (Proteus spp., Enterococcus spp., Staphylococcus spp.) as well as molds and yeasts, were present in both grain-included and grain-free foods. The obtained results showed that in terms of microbiological safety, grain-included foods come out worse, because microorganisms were detected more frequently in this type of dry dog food.

Singularity of the Spectrum for Smooth Area-Preserving Flows in Genus Two and Translation Surfaces Well Approximated by Cylinders.

We consider smooth flows preserving a smooth invariant measure, or, equivalently, locally Hamiltonian flows on compact orientable surfaces and show that, when the genus of the surface is two, almost every such locally Hamiltonian flow with two non-degenerate isomorphic saddles has singular spectrum. More in general, singularity of the spectrum holds for special flows over a full measure set of interval exchange transformations with a hyperelliptic permutation (of any number of exchanged intervals), under a roof with symmetric logarithmic singularities. The result is proved using a criterion for singularity based on tightness of Birkhoff sums with exponential tails decay. A key ingredient in the proof, which is of independent interest, is a result on translation surfaces well approximated by single cylinders. We show that for almost every translation surface in any connected component of any stratum there exists a full measure set of directions which can be well approximated by a single cylinder of area arbitrarily close to one. The result, in the special case of the stratum H ( 1 , 1 ) , yields rigidity sets needed for the singularity result.

Size distribution of microbial aerosols in overground and subterranean treatment chambers at health resorts.

PURPOSE: to perform comparative analyzes of the size distributions of bacteria and fungi in the air of overground therapy chambers in Szczawnica sanatorium and subterranean inhalation chambers in Bochnia Salt Mine health resort taking into account influence of the season and presence of pathogenic species. METHODS: bioaerosol samples were collected using 6-stage Andersen impactor. Bacterial and fungal aerosol concentrations and size distributions were calculated and isolated microorganisms were taxonomically identified based on their morphological, biochemical, and molecular features. Results: in both treatment rooms and atmospheric (outdoor) air, the acceptable microbial pollution levels were periodically exceeded. The size distribution analyzes revealed that in the case of bacteria - emission from the patients and in the case of fungi - transport with atmospheric (outdoor) air were the major processes responsible for microbiological contamination of indoor premises. The majority of microbial particulates were present in the air of studied premises as single bacterial vegetative cells, spores and fungal conidia or (most commonly) formed small microbial or microbial-dust aggregates. This phenomenon may have a significant effect on patients' actual exposure (especially on those treated for respiratory diseases) in terms of the dose of inhaled particles. CONCLUSIONS: the microbiological quality of the air in sanatoriums and health resorts is a key factor for their therapeutic and prophylactic functions. When microbial pollution crossed the acceptable level, the measures that enable reducing undesirable contamination should be introduced, especially if large groups of patients undergo such therapy.

Bacterial aerosols in a municipal landfill environment.

Landfills collecting substantial amounts of municipal waste support multiplication of different bacteria mainly due to organic matter contained in the deposited materials. With time, they may become active emission sources of these microorganisms. Taking into account both occupational and public health and safety, there is an indisputable necessity to monitor the level of air contamination caused by both bacterial cells and their components (e.g., endotoxins). In this study, the concentrations of total viable bacteria (TVB), and Gram-negative bacteria (GNB), as well as their particle size distributions and concentrations of GNB endotoxins were assessed at various locations within the landfill area. The concentrations of TVB and GNB in the air samples changed depending on the season, location (i.e. active sector versus surroundings) and landfill activity level (i.e. exploitation or standstill periods). Higher abundances of endotoxins were found during the standstill period, and they were significantly correlated with organic dust concentrations. The microbial particle size distribution was associated with the landfill operational state, being predominated by fine below 4.7 µm and coarse fractions above 7.0 µm within the active sector during exploitation and standstill periods, respectively. These results supported by a spatial distribution of bacterial aerosol indicate a clear impact of operated landfill on microbiological air quality within the occupied location and nearby areas. Considering health and safety of landfill workers and neighboring residents, who can be exposed to airborne microbial pollutants, repeated bioaerosol monitoring need to be established. It should facilitate both a special planning within the landfill area and undertaking preventive actions in its near and distant surroundings.

Assessment of microbiological and chemical properties in a municipal landfill area.

This study aimed at determining the environmental hazards for soils posed by a large municipal landfilll. The concentrations of heavy metals and Policyclic Aromatic Hydrocarbons, as well as microbial composition (i.e., mesophilic bacteria, actinomycetes, molds, Salmonella, Staphylococcus, Clostridium perfringens) in four soils within and in the vicinity of the landfill were evaluated and compared to waste samples. Both chemical and microbiological analyses revealed only limited contamination of surrounding areas. Although the increased alkalinity of soils was detected, the concentrations of heavy metals and Polycyclic Aromatic Hydrocarbons (PAHs) did not exceed the admissible values. All examined microbial groups were abundant in soil and waste. The highest microbial cell numbers were observed in warm summer and spring months. Although the site south of the landfill shows no trace of microbial contamination, pathogenic bacteria were found north of the landfill. This may suggest that there are other, more effective, transmission routes of bacteria than groundwater flow.

Bioaerosols of subterraneotherapy chambers at salt mine health resort.

Nowadays, an inhalation of naturally generated aerosols has again become a widely practiced method of balneological treatment of various respiratory diseases. The aim of this study was to characterize the microbial aerosol of subterraneotherapy chambers at the Bochnia Salt Mine Health Resort in southern Poland. The measurements were carried out using a 6-stage Andersen impactor over a period of 1 year in both indoor (i.e., two subterranean chambers, where curative treatments took place) and outdoor air. The maximum bacterial aerosol concentrations in the chambers reached 11,688 cfu/m3. In such interiors, a high-performance method of microbial contaminant reduction need be introduced, especially when large groups of young patients are medically cured. Respecting fungal aerosol, its average indoor concentration (88 cfu/m3) was significantly lower than outdoor level (538 cfu/m3). It confirms that ventilation system provides efficient barrier against this type of biologically active propagules. Among identified micro-organisms, the most prevalent indoors were Gram-positive cocci, which constituted up to 80 % of airborne microflora. As highly adapted to the diverse environments of its human host (skin, respiratory tract), they can be easily released in high quantities into the air. The number of people introduced into such subterranean chambers should be in some way limited. The analysis of microclimate parameters revealed that temperature and relative humidity influenced significantly the level of bacterial aerosol only. Hence, a constant control of these parameters should be scrupulously superintended at this type of subterranean premises.

Assessment of relationship between fungal aerosol within a municipal dump and epiphytic mycoflora of crop plants.

A field study was performed to assess whether fungal aerosol of a municipal dump may impact on quantitative and qualitative characteristics of epiphytic mycoflora of crop plants cultivated in vicinity of the dump. Sampling sites were located at every side of the dump. Plant samples were collected from field bean, spring wheat and potato. The highest concentration of fungal aerosol was found at the field located south of the dump within the zone of 250 m next to its borders. For this zone, the most numerous and diverse mycoflora was ascertained, and the plants cultivated were the most damaged. The results suggest that the municipal dump was not the source of phytopathogenic fungi; however, different emissions of contaminants from the dump might cause a decline in the intrinsic plant resistance against the pathogens.

Microbial air quality at Szczawnica sanatorium, Poland.

Nowadays, sanatorium treatment is undergoing a renaissance; however, data on air quality in such premises are scarce. The aim of this study was to characterize microbial air quality at the Szczawnica sanatorium in Southern Poland. The bioaerosol measurements were carried out using a 6-stage Andersen impactor over a period of one year in 3 naturally ventilated sanatorium premises (where different curative treatments took place) and in outdoor air. The indoor and outdoor concentrations of fungal aerosol were always below 1,600 cfu/m(3). With regard to bacterial contamination, the highest concentrations (up to 6,223 cfu/m(3)) were usually noted when the patients were present and underwent curative procedures. Such concentrations crossed the Polish threshold limit values, which suggest that natural ventilation in this type of premises did not ensure the proper air quality; therefore a high-performance ventilation or air-conditioning system should be introduced to provide the "clean" air into the curative treatment rooms. Qualitative evaluation of bioaerosols revealed that the most prevalent indoors were Gram-positive cocci, mesophilic actinomycetes, and filamentous fungi. Analysis of microclimate parameters confirmed that ony relative humidity of the air influenced significantly the levels and composition of microbial aerosols. Hence, the constant control of this parameter should be scrupulously supervised at sanatorium premises.

[Municipal landfill site in Krzyz near Tarnów as source of microbiological factors harmful to environment and human health]. / Skladowisko odpadów komunalnych w Tarnowie-Krzyzu jako zródlo mikrobiologicznych czynników szkodliwych dla srodowiska i zdrowia czlowieka.

The present study aimed to evaluate microbiological pollution of air with microorganisms belonging to different taxonomic and physiological groups, and to examine whether the effect of the municipal landfill site in Krzyz changes at various study sites located: in so called "zero zone" (operating landfill), at different distances from the landfill and in Tarnów. Microbiological studies of atmospheric air were carried out from May 1998 to April 2001. Measurements were taken at 10 study sites located at the operating municipal landfill site in Krzyz, inside and outside of its protection zone. Microbial air pollution standard (PN-89/Z-04111/02 and PN-89/Z-04111/03) were used to evaluate the impact of municipal landfill site on the atmospheric environment. The standards were most often exceeded by hemolytic bacteria, (277 cases out of 360 measurements) i.e. 76.9%, and Actinomycetes (213 cases out of 360 measurements) i.e 59.1%, while by fungi (26 cases out of 360 measurements) i.e 7.2% and bacteria (42 cases out of 360 measurements) i.e 11.6% in a lesser degree. The standards were most often exceeded in operating land fill site sector, at the gateway to the land fill site and in partially reclaimed sector. Fewest cases of standard exceedance were recorded in control site (located outside the landfill site), near built-up area and before the entrance to the land fill site.