The taxonomic position of a strain isolated from kerosene-contaminated soil in Hungary and formerly misidentified as Brevundimonas vesicularis was examined using a polyphasic approach. The isolate, designated CHB-20p T , could be clearly assigned to the genus Chryseobacterium (family Flavobacteriaceae) on the basis of 16S rRNA gene sequence similarity. Strain CHB-20p T , a moderate oil degrader, was a Gram-negative, aerobic, mesophilic microbe with a temperature optimum of 28-30 6C. Predominant fatty acids were iso-C 15 : 0 , summed feature 3 (comprising C 16 : 1 v7c and/or iso-C 15 : 0 2-OH) and iso-C 17 : 0 3-OH. Menaquinone-6 (MK-6) was the predominant respiratory quinone; MK-5 was present as a minor component. The almost complete 16S rRNA gene sequence of strain CHB-20p T shared 94-97 % similarity with sequences of the type strains of species of the genus Chryseobacterium. DNA-DNA relatedness between strain CHB-20p T and its closest relative, Chryseobacterium caeni, was lower than 46 %. Moreover, several diagnostic phenotypic properties distinguished strain CHB-20p T from C. caeni. On the basis of biochemical, chemotaxonomic and genotypic data, isolate CHB-20p T represents a novel species within the genus Chryseobacterium, Chryseobacterium hungaricum sp. nov.; the type strain is CHB-20p T (5NCAIM B2269 T 5DSM 19684 T ).
The main aim of this paper was the comprehensive estimation of the occurrence rate and the antibiotic-resistance conditions of opportunistic pathogen Pseudomonas aeruginosa in hydrocarbon-contaminated environments. From 2002 to 2007, 26 hydrocarbon-contaminated sites of Hungary were screened for the detection of environmental isolates. Altogether, 156 samples were collected and examined for the determination of appearance, representative cell counts, and antibiotic-resistance features of P. aeruginosa. The detected levels of minimal inhibitory concentrations of ten different drugs against 36 environmental strains were compared to the results of a widely used reference strain ATCC 27853 and four other clinical isolates of P. aeruginosa. Based on our long-term experiment, it can be established that species P. aeruginosa was detectable in case of 61.5% of the investigated hydrocarbon-contaminated sites and 35.2% of the examined samples that shows its widespread occurrence in polluted soil-groundwater systems. In the course of the antibiotic-resistance assay, our results determined that 11 of the examined 36 environmental strains had multiple drug-resistance against several clinically effective antimicrobial classes: cephalosporins, wide spectrum penicillins, carbapenems, fluoroquinolones, and aminoglycosides. The fact that these multiresistant strains were isolated from 8 different hydrocarbon-contaminated sites, mainly from outskirts, confirms that multiple drug-resistance of P. aeruginosa is widespread not only in clinical, but also in natural surroundings as well.
Due to changes in the Hungarian legislation, the ATEVSZOLG Corporation, which treats waste of animal origin, has started to search for a new way to dispose and reuse this waste by recycling it without the loss of materials produced at high cost from the natural cycle. Since this waste contains a high concentration of fat, one major objective of the composting experiment was to investigate the effect of composts with high fat contents on the biological activity of the soil. The other aim was to investigate the impact of sterilising heat treatment and of high temperature conditions during the composting process on the number of pathogenic microbes, which are common in waste of animal origin. The quality and quantity of the fat in the soil samples were measured using a gas chromatograph. The effect of the high fat content on the biological activity of the soil was measured as the difference between the control and the treated soil samples for CFU number of fat-degrading microbes and the difference in the biological activity of the samples in an Oxi-Top soil respirator system. The effect of heat treatment on pathogenic microbes was investigated on the basis of the number of Clostridium, faecal coliforms and Pseudomonas aeruginosa microbes. The results showed that the high fat content deposited with the composts was well utilised, and that its degradation did not cause a problem for the microbes living in the soil. This was proved both by the results of the CFU experiments and by the parameters in the Oxi-Top soil respirator system. The heat treatment successfully decreased the number of pathogenic microbes to a low risk level. The results indicated that the mixing of the heat-treated, sterilised basic materials of the composts with untreated, non-sterilised materials such as sewage sludge should be avoided, due to the risk of re-infecting the compost with pathogens. The composts produced from animal waste using the heat treatment developed by the ATEVSZOLG Corp. have the same infection risk as the composts produced from animal manure or sewage sludge.
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