Biomedical subjects

J Vytrasová

Publications and source records attributed to J Vytrasová.

7 recordsLinked to original sources

PubMed2006

Identification of Arcobacter species using phospholipid and total fatty acid profiles.

High-performance liquid chromatography (HPLC) and gas chromatography-mass spectrometry (GC-MS) were used to analyze the phospholipids and fatty acids of four Arcobacter species (becoming routinely isolated from a wide variety of food sources, especially of animal origin) to provide information for the identification within these species. Phospholipid differences were observed in the HPLC profiles. GC-MS analysis provided a complete fatty acid composition for each arcobacter that after pattern recognition analysis allows taxonomic classification of each species.

Arcobacter↗

PubMed2004

The effect of acetic acid, citric acid, and trisodium citrate in combination with different levels of water activity on the growth of Arcobacter butzleri in culture.

The influence of weak organic acids and trisodium citrate in combination with a high or a reduced water activity (aw) was investigated when a population of Arcobacter butzleri was exposed to a low concentration of acetic or citric acid, and trisodium citrate combined with high (0.993) and reduced (0.977) aw in culture broth at 30 degrees C. Regardless of water activity, acetic and citric acid (> 0.2%) inhibited the growth of A. butzleri with no viable cells detected after 4-5 h of incubation. Enhanced survival was found at reduced aw with addition of acetic acid. In contrast, after exposure to citric acid in combination with reduced aw inactivation was more rapid than that after being exposed to high water activity. Incorporation of trisodium citrate in combination with reduced aw (0.977) would probably not confer any extra protection. Concentrations of organic acid widely used in meat decontamination processing represent feasible tools for reducing A. butzleri contamination and hence the risk of Arcobacter infection.

Acetic Acid↗

PubMed2003

Isolation of Arcobacter butzleri and A. cryaerophilus in samples of meats and from meat-processing plants by a culture technique and detection by PCR.

A pilot survey of sources of contamination with arcobacters (representing a potential risk for humans) was done in a wide range of samples involved various kinds of meat (beef, pork, meat products, chilled chickens, etc.) from a retail level and domestic farming. Sanitary practices in slaughterhouses and production lines were checked in two different plants (a beef and pork production and a chicken processing plant). The method is based on a selective enrichment to isolate suspect strains, in combination with a PCR technique specific for arcobacters. The choice of a suitable enrichment broth and a plating agar was made with the use of pure bacterial strains and by means of real meat samples seeded with Arcobacter butzleri. The PCR technique was optimized to allow differentiation of a 1223 bp product, typical of the genus Arcobacter, and a product of 686 bp, specific for A. butzleri a total number of 198 samples were tested, of that 33 (17%) were found to be positive for the genus Arcobacter but only 22 (11%) for A. butzleri.

Agar↗

PubMed2003

Detection of aflatoxigenic fungi in feeds using the PCR method.

The possibility of using the polymerase chain reaction (PCR) to speed up and specify the detection of aflatoxigenic fungi isolated from feed was investigated. The method, applied to 2 genes encoding the biosynthesis of aflatoxins (apa-2 and ver-1), was optimized on two collection cultures (Aspergillus flavus CCM F-108 and A. parasiticus CCM F-550). The specificity of the optimized PCR method was proved on collection cultures of different kinds of fungi. Fifty feed samples out of which 18 showed positive findings of aflatoxigenic fungi on an Aspergillus Flavus and Parasiticus Agar (AFPA) medium were tested. Isolated strains of Aspergillus strains were verified using the PCR method; its reaction products were detected in 1% agarose gel by electrophoresis. The results almost exclusively matched those gained from the AFPA medium.

Aflatoxins↗

PubMed2002

Occurrence of xerophilic fungi in bakery gingerbread production.

The production process of a coconut type of gingerbread was examined for possible sources of contamination with xerophilic fungi. In the production flow chart, critical control points were found at which some effective steps could be made to eliminate undesirable fungal contamination, affected by water activity and temperature, and to prevent mould spoilage of the products. The following xerophilic fungi were detected, isolated and identified: Eurotium amstelodami, E. chevalieri, E. herbariorum, E. rubrum and Wallemia sebi. The resistance of these fungi against elevated temperature and preserving agents was investigated. It was found that Eurotium species were more resistant than W. sebi. Preservation against xerophilic fungi was more effective with the use of propionic acid than with potassium sorbate.

Ascomycota↗

PubMed2001

[Is the diffusion method useful for testing the effectiveness of biocides?].

The authors tested the fungicide effect of different biocides by the diffusion method. Its principle involves pipeting samples of the tested fungicide preparations into pits in an agar medium on Petri dishes. The agar is inoculated over the whole surface with spores of fungi. It is incubated at 28 degrees C for 2 to 3 days. The size of the inhibition zones in the increments of fungi round the pits with the preparation are recorded. The authors discuss the suitability of this method for different types of preparations with regard to the results they assembled.

Antifungal Agents↗

PubMed2000

Application of a chromogenic medium and the PCR method for the rapid confirmation of L. monocytogenes in foodstuffs.

Detection of Listeria monocytogenes in foodstuffs by conventional cultivation methods carried out according to EN ISO guidelines is rather time-consuming. Therefore, two alternative methods were applied for rapid confirmation of L. monocytogenes in foodstuffs. Inoculum from liquid selective broth was plated on PALCAM and OXFORD agar and on chromogenic agar medium RAPID L. mono. Suspect colonies from PALCAM were confirmed according to EN ISO standards and by the multiplex PCR method. In total, 990 samples of foodstuffs were investigated and 63 strains of L. monocytogenes were isolated. The chromogenic medium RAPID L. mono provided results comparable to PCR, it is easier to handle and provides considerable financial savings.

Chromogenic Compounds↗