[Microbiological air quality in some kindergartens and antibiotic resistance of bacteria of the Staphylococcus spp. genus]. / Mikrobiologiczna jakosc powietrza w wybranych przedszkolach oraz antybiotykoopornosc bakterii z rodzaju Staphylococcus spp..

BACKGROUND: Microbiological contamination or tne air and the acquisition of the antibiotic resistance by pathogenic bacteria is a growing phenomenon that has a substantial impact on the quality of our health. This problem applies mainly to public areas where we spend a large part of our lives. This study was focused on the microbiological analysis of the air in some kindergartens and antibiotic resistance of bacteria of the Stephylococcus spp. genus. The identification of the isolated mould fungi has been also made. MATERIAL AND METHODS: Air samples were collected from classrooms in the seasonal cycle in the mornings and afternoons using 2 methods, sedimentation and impact. Air samples collected outside the kindergartens served as controls. Air quality assessments were based on the groups of indicator microorganisms, according to Polish standards. The susceptibility of isolated staphylococci was assessed with the disc-diffusion method, using 8 different classes of antibiotics, in line with the recommendations of the European Committee on Antimicrobial Susceptibility Testing (EUCAST). RESULTS: The analyses show that, regardless of the method, the total number of heterothropic bacteria and staphylococci in the air of the analyzed kindergartens exceeded the allowable limits. There was no air-pollution with the fungal infection. Based on the antibiogram, it was found that Staphylococcus spp. strains showed the highest sensitivity to chloramphenicol and the lowest to penicillin and gentamicin. Among the fungi moulds of the genus Cladosporium predominated. CONCLUSIONS: The results of the analyses highlight the need for regular health checks and further research to help identify biological factors that may significantly affect the quality of health of people living in public spaces.

Neustonic versus epiphytic bacteria of eutrophic lake and their biodegradation ability on deltamethrin.

This study evaluated biodegradation of the insecticide deltamethrin (1 µg l(-1)) by pure cultures of neustonic (n = 25) and epiphytic (n = 25) bacteria and by mixed cultures (n = 1), which consisted of a mixture of 25 bacterial strains isolated from the surface microlayer (SM ≈ 250 µm) and epidermis of the Common Reed (Phragmites australis, (Cav.) Trin. ex Steud.) growing in the littoral zone of eutrophic lake Chelmzynskie. Results indicate that neustonic and epiphytic bacteria are characterized by a similar average capacity to degrade deltamethrin. After a 15-day incubation, bacteria isolated from the surface microlayer reduced the initial concentration of deltamethrin by 60%, while the average effectiveness of the bacteria found on the Common Reed equaled 47%.

Influence of the root system of the Common Osier (Salix viminalis L.) on abundance of heterotrophic bacteria in the willow sewage treatment system.

The impact of the Common Osier (Salix viminalis L.) root system on number (CFU) of heterotrophic bacteria and their production in a soil-willow filter was examined. The Osier rhizosphere was found to be suitable habitat for growth of the examined microbial group, and the root system stimulated development of heterotrophic bacteria. The rhizosphere bacteria to control soil bacteria (R:C) ratio oscillated between 2.48 and 2.75 depending on the location of sample collection. The highest abundance of bacteria as well as highest bacterial production was observed at location I, near sewage discharge onto the plot. There was a significant positive correlation between the number of heterotrophic bacteria and the bacterial production.

Biodegradation of carbendazim by epiphytic and neustonic bacteria of eutrophic Chelmzynskie Lake.

The paper presents a study on biodegradation of carbendazim (1 mg/l) by homogeneous cultures of epiphytic (n = 25) and neustonic (n = 25) bacteria and heterogeneous (n = 1) cultures containing a mixture of 25 bacterial strains isolated from epidermis of the Common Reed (Phragmites australis, (Cav.) Trin. ex Steud.) and surface microlayer (SM approximately 250 microm) of eutrophic lake Chelmzynskie. Results indicate that epiphytic bacteria are characterized by higher average capacity to decompose carbendazim than neustonic bacteria (p < 0.05). The half-life ofcarbendazim in epiphytic bacterial cultures equaled an average of 60 days. In the same period, neustonic bacteria reduced the concentration of the fungicide by 31%. The level of carbendazim biodegradation in mixed cultures of epiphytic and neustonic bacteria after 20-day incubation was lower than the biodegradation level in homogeneous cultures. Sixty-day homogeneous cultures of epiphytic and neustonic bacteria were characterized by a higher mean level of carbendazim biodegradation than mixed cultures. After 40-day incubation, mean values of biodegradation of the fungicide in homogeneous and mixed cultures were similar. It was demonstrated that among epiphytic bacteria, Pseudomonas luteola was the most efficient organism in reducing the concentration of carbendazim. Among neustonic bacteria, Burkholderia cepacia and Aeromonas hydrophila were the most effective in degradation of the fungicide.

Occurrence and activity of microorganisms in shrimp waste.

This study aimed to determine the occurrence and respiration activity of heterotrophic bacteria and fungi in shrimp shell waste and to evaluate the role of chitinolytic bacteria and fungi in its decomposition. The highest levels of bacteria were found in shrimp heads sections and the lowest in exoskeletons. The level of fungi was much lower, with the highest proportion present in heads sections and the lowest in exoskeletons. Chitinolytic bacteria constituted a small percentage of the total heterotrophic bacteria in fresh shrimp waste, averaging 4% in exoskeletons, 2.4% in all parts, and 2% in heads. No chitinolytic bacteria were detected in stored waste. In contrast, the percentage of chitinolytic fungi in shrimp waste was much higher than that of bacteria. Chitinolytic fungi constituted 25-60% of the total fungi in fresh waste and 15-40% in stored waste. Chitinolytic bacteria isolated from heads sections were characterized by the highest chitinolytic activity, averaging 11.2 nmol of methylumbelliferyl x mg(-1) protein x h(-1), whereas the lowest activity was in strains from exoskeletons, averaging 3.2 nmol of methylumbelliferyl x mg(-1) protein x h(-1). The chitinolytic activity of fungi isolated from all parts waste, head sections, and exoskeletons was similar. The respiration activity of microorganisms in fresh and stored waste was similar. Oxygen consumption activity increased during incubation and approached a saturation value between days 4 and 5. No correlation between the end value of respiratory activity in the analyzed section of shrimp discard after 5 days and the level of bacteria and fungi was observed. The only significant correlation observed was between the respiratory activity of the shrimp and the level of fungi. The respiration activity significantly depended on the analyzed section of shrimp discard (p<0.000).