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The use of infrared spectroscopy and artificial neural networks for detection of uropathogenic Escherichia coli strains' susceptibility to cephalothin

100%

Lechowicz Ł., Urbaniak M., Adamus-Białek W., Kaca W.

2013

vol. 60

issue 4

713-718

Background & Aims: Infrared spectroscopy is an increasingly common method for bacterial strains' testing. For the analysis of bacterial IR spectra, advanced mathematical methods such as artificial neural networks must be used. The combination of these two methods has been used previously to analyze taxonomic affiliation of bacteria. The aim of this study was the classification of Escherichia coli strains in terms of susceptibility/resistance to cephalothin on the basis of their infrared spectra. The infrared spectra of 109 uropathogenic E. coli strains were measured. These data are used for classification of E. coli strains by using designed artificial neural networks. Results: The most efficient artificial neural networks classify the E. coli sensitive/resistant strains with an error of 5%. Conclusions: Bacteria can be classified in terms of their antibiotic susceptibility by using infrared spectroscopy and artificial neural networks.

Analysis of uropathogenic Escherichia coli biofilm formation under different growth conditions

100%

Adamus-Białek W., Kubiak A., Czerwonka G.

2015

vol. 62

issue 4

765-771

The ability to form different types of biofilm enables bacteria to survive in a harsh or toxic environment. Different structures of biofilms are related to different surfaces and environment of bacterial growth. The aim of this study was analysis of the biofilm formation of 115 clinical uropathogenic Escherichia coli strains under different growth conditions: surface for biofilm formation, medium composition and time of incubation. The biofilm formation after 24 h, 48 h, 72 h and 96 h was determined spectrophotometrically (A531) after crystal violet staining and it was correlated with bacterial growth (A600). The live and dead cells in biofilm structures was also observed on the glass surface by an epi-fluorescence microscope. Additionally, the presence of rpoS, sdiA and rscA genes was analyzed. The statistical significance was estimated by paired T-test. The observed biofilms were different for each particular strain. The biofilm formation was the highest in the rich medium (LB) after 24 h and its level hasn't changed in time. When biofilm level was compared to bacterial growth (relative biofilm) - it was higher in a minimal medium in comparison to enriched medium. These results suggest that most of the bacterial cells prefer to live in a biofilm community under the difficult environmental conditions. Moreover, biofilm formation on polyurethane surface did not correlate with biofilm formation on glass. It suggests that mechanisms of biofilm formation can be correlated with other bacterial properties. This phenomenon may explain different types of biofilm formation among one species and even one pathotype - uropathogenic Escherichia coli.

The effects of nickel(II) complexes with imidazole derivatives on pyocyanin and pyoverdine production by Pseudomonas aeruginosa strains isolated from cystic fibrosis

64%

Gałczyńska K., Kurdziel K., Adamus-Białek W., Wąsik S., Szary K., Drabik M., Węgierek-Ciuk A., Lankoff A., Arabski M.

2015

vol. 62

issue 4

739-745

Pseudomonas aeruginosa infection is problematic in patients with cystic fibrosis (CF). P. aeruginosa secretes a diversity of pigments, such as pyocyanin and pyoverdine. The aim of this study was to evaluate the effects of complexes of nickel(II) ([Ni(iaa)2(H2O)2]·H2O (iaa = imidazole-4-acetate anion), [Ni(1-allim)6](NO3)2 (1-allim = 1-allylimidazole) and NiCl2 on pyocyanin and pyoverdine production by 23 strains of P. aeruginosa isolated from cystic fibrosis under growth conditions specific for the CF respiratory system. The antibacterial effects and biophysical properties of the tested substances were measured by spectrofluorometric techniques, as well as by laser interferometry, confocal and atomic force microscopy. The cytotoxic properties of all compounds were measured by Annexin/IP assay against A549 cells. All tested compounds have no effect on pyocyanin production and decrease the pyoverdine secretion in about 40% of tested P. aeruginosa strains at non-cytotoxic range of concentrations. Imidazole-4-acetate anion and 1-allylimidazole have good diffusion properties in the mature P. aeruginosa PAO1 biofilm. In conclusion, the tested nickel(II) complexes do not have clinical implications in P. aeruginosa eradication in cystic fibrosis. The diffusion properties of 1-allylimidazole and imidazole-4-acetate and their lack of effect on A549 cells suggest that they might be considered for chemical synthesis with other transition metals.

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3 Acta Biochimica Polonica

2 2015

1 2013

3 Adamus-Białek W.

1 Arabski M.

1 Czerwonka G.

1 Drabik M.

1 Gałczyńska K.

1 Kaca W.

1 Kubiak A.

1 Kurdziel K.

1 Lankoff A.

1 Lechowicz Ł.

1 Szary K.

1 Urbaniak M.

1 Wąsik S.

1 Węgierek-Ciuk A.

Search results

The use of infrared spectroscopy and artificial neural networks for detection of uropathogenic Escherichia coli strains' susceptibility to cephalothin

Analysis of uropathogenic Escherichia coli biofilm formation under different growth conditions

The effects of nickel(II) complexes with imidazole derivatives on pyocyanin and pyoverdine production by Pseudomonas aeruginosa strains isolated from cystic fibrosis