Seasonal and spatial diversity of picocyanobacteria community in the Great Mazurian Lakes derived from DGGE analyses of ITS region of rDNA and cpcBAIGS [corrected] markers.

The seasonal and spatial diversity of picocyanobacteria (Pcy) in lakes of the Great Mazurian Lakes (GLM) system was examined by DGGE analysis of molecular markers derived from the 16S-23S internal transcribed spacer (ITS) of the ribosomal operon and the phycocyanin operon (cpcBA-IGS). The study of nine lakes, ranging from mesotrophy to hypereutrophy, demonstrated seasonal variance of Pcy. The richness and Shannon diversity index calculated on the basis of both markers were higher in spring and lower in early and late summer. No statistically significant relationships were found between the markers and trophic status of the studied lakes or Pcy abundance. There were, however, statistically significant relationships between the diversity indices and sampling time. The analysis pointed to a different distribution of the two markers. The ITS marker exhibited more unique sequences in time and space, whereas a greater role for common and ubiquitous sequences was indicated by the cpcBA-IGS data. Examination of the Pcy community structure demonstrated that communities were grouped in highly similar clusters according to sampling season/time rather than to the trophic status of the lake. Our results suggest that time is more important than trophic status in shaping the diversity and structure of Pcy communities. The seasonal changes in picocyanobacteria and differences in diversity and community structures are discussed in the context of well-established ecological hypotheses: the PEG model, intermediate disturbance hypothesis (IDH), and horizontal gene transfer (HGT).

[Significance of the efflux phenomenon as a mechanism of bacterial resistance on active substances of biocide]. / Znaczenie zjawiska efflux jako mechanizmu opornosci bakterii na substancje czynne srodków dezynfekcyjnych.

Efflux phenomenon induced by the presence of efflux pumps is one of the bacterial resistance mechanisms against active substances ofbiocides. Proteins and protein systems create efflux pumps, which are connected with the cell envelope structure ofbacteria. The efflux pump's function is transportation of active substances of disinfectants outside the bacterial cell. The biocides active substances rinsed out of bacterial cell by efflux were described for quaternary ammonium compounds, biguanides, phenols and diamidine. Bacterial resistance induced by efflux was not confirmed in the presence of such active substances like: alcohols, aldehydes, peroxides and chlorine compounds and their derivates. Bacterial resistance to active substance ofbiocides can be caused by two or more resistance mechanisms i.e. efflux mechanisms and reduce diffusion. The cooperation of resistance mechanisms to biocides can result difficulties in pathogenic bacteria eradication. The spread of these bacteria can be an epidemic threat.

[Waste generated in Polish hospitals during the years 2005 - 2009]. / Odpady wytwarzane w polskich szpitalach w latach 2005 - 2009.

The medical institutions generate mainly municipal and medical waste. The medical waste includes infectious waste, dangerous but not infectious waste (toxic) and medical not dangerous waste. They have to be correctly identified, properly sorted and suitably neutralized. Questionnaires investigations were conducted on the basis on the forms worked out at National Institute of Public Health - National Institute of Hygiene. Information from above seven hundred seventy hospitals were collected. Inquiries indicated that during the period of years 2005-2009 over two hundred thousand beds per year were available. The degree of the use run from 52% to 100%, in average 72%. The largest fraction of the waste from all institutions were municipal waste run from 80% to 90%. Dangerous waste in following years were between 9.9% and 18.1%. The great part of dangerous waste were infections waste, which content ranged from 8.7 to 17.1%. Very low quantity of medical not dangerous waste was noted (1-1,7%). The majority of infectious medical waste were neutralized outside hospitals by the companies having suitable permissions. The thermal conversions (burning) was the most often used method.