Background: In recent years, significant resistance of microorganisms to antibiotics has been observed. A biofilm is a structure that significantly aids the survival of the microbial population and also significantly affects its resistance. Methods: Thyme and clove essential oils (EOs) were subjected to chemical analysis using gas chromatography coupled to mass spectrometry (GC-MS) and gas chromatography with a flame ionization detector (GC-FID). Furthermore, the antimicrobial effect of these EOs was tested in both the liquid and vapor phases using the volatilization method. The effect of the EOs on growth parameters was monitored using an RTS-8 bioreactor. However, the effect of the EOs on the biofilm formation of commonly occurring bacteria with pathogenic potential was also monitored, but for less described and yet clinically important strains of Arcobacter spp. Results: In total, 37 and 28 compounds were identified in the thyme and clove EO samples, respectively. The most common were terpenes and also derivatives of phenolic substances. Both EOs exhibited antimicrobial activity in the liquid and/or vapor phase against at least some strains. The determined antimicrobial activity of thyme and clove oil was in the range of 32-1024 µg/mL in the liquid phase and 512-1024 µg/mL in the vapor phase, respectively. The results of the antimicrobial effect are also supported by similar conclusions from monitoring growth curves using the RTS bioreactor. The effect of EOs on biofilm formation differed between strains. Biofilm formation of Pseudomonas aeruginosa was completely suppressed in an environment with a thyme EO concentration of 1024 µg/mL. On the other hand, increased biofilm formation was found, e.g., in an environment of low concentration (1-32 µg/mL). Conclusions: The potential of using natural matrices as antimicrobials or preservatives is evident. The effect of these EOs on biofilm formation, especially Arcobacter strains, is described for the first time.

• Klíčová slova
• Arcobacter, antimicrobial effect, biofilm formation, clove, essential oil, thyme,
• Publikační typ
• časopisecké články MeSH

Campylobacter jejuni is the most frequent cause of bacterial gastrointestinal food-borne infection worldwide. The transmission of Campylobacter and Arcobacter-like species is often made possible by their ability to adhere to various abiotic surfaces. This study is focused on monitoring the biofilm ability of 69 strains of Campylobacter spp. and lesser described species of the Arcobacteraceae family isolated from food, water, and clinical samples within the Czech Republic. Biofilm formation was monitored and evaluated under an aerobic/microaerophilic atmosphere after cultivation for 24 or 72 h depending on the surface material. An overall higher adhesion ability was observed in arcobacters. A chi-squared test showed no association between the origin of the strains and biofilm activity (p > 0.05). Arcobacter-like species are able to form biofilms under microaerophilic and aerobic conditions; however, they prefer microaerophilic environments. Biofilm formation has already been demonstrated at refrigerator temperatures (5 °C). Arcobacters also showed higher biofilm formation ability at the temperature of 30 °C. This is in contrast to Campylobacter jejuni NP 2896, which showed higher biofilm formation ability at temperatures of 5-30 °C. Overall, the results demonstrated the biofilm formation ability of many strains, which poses a considerable risk to the food industry, medical practice, and human health.

• Klíčová slova
• Aliarcobacter spp., Arcobacter-like, Campylobacter spp., abiotic surfaces, biofilm formation, food processing materials, temperature condition,
• Publikační typ
• časopisecké články MeSH

Hydrolates obtained via the hydrodistillation and steam distillation of Lavandulaangustifolia Mill., Syzygiumaromaticum L., Foeniculumvulgare Mill., and Laurusnobilis L. were analyzed by gas chromatography with flame ionization detector (GC-FID) and gas chromatography coupled to mass spectrometry (GC-MS). Additionally, the hydrolates were evaluated for antimicrobial activity (disk-diffusion and microdilution method), influence on biofilm formation (Christensen method) and cytotoxicity of concentrated hydrolates against human cell lines (A549) by xCELLigence system. Using chemical analysis, 48, 9, 13 and 33 different components were detected in lavender, clove, fennel and laurel hydrolates, respectively. Lavender hydrolate contained the largest proportion of 1,8-cineol, linalool furanoxide, and linalool. The main components of laurel hydrolate were 1,8-cineol, 4-terpineol and α-terpineol. Fenchone and estragole were the most abundant in fennel hydrolate, and eugenol and eugenyl acetate in clove hydrolate. Concentrated hydrolates showed significant antimicrobial activity. Clove hydrolate was among the most antimicrobially active agents, most preferably against C. albicans, with an inhibition zone up to 23.5 mm. Moreover, concentrated hydrolates did not show any cytotoxic effect again8 st human A549 cells. In the presence of the non-concentrated hydrolates, significantly reduced biofilm formation was observed; however, with concentrated clove hydrolate, there was an increase in biofilm formation, e.g., of A. thereius, A. lanthieri, and A. butzleri. Research shows new findings about hydrolates that may be important in natural medicine or for preservation purposes.

• Klíčová slova
• Arcobacter-like bacteria, Foeniculum vulgare, Laurus nobilis, Lavandula angustifolia, Syzygium aromaticum, antimicrobial activity, biofilm formation, distillation, gas chromatography, hydrolates,
• MeSH
• antiinfekční látky farmakologie   MeSH
• Arcobacter účinky léků   MeSH
• buňky A549 MeSH
• Candida albicans účinky léků   MeSH
• destilace MeSH
• levandule chemie   MeSH
• lidé MeSH
• nádory plic farmakoterapie   MeSH
• oleje prchavé farmakologie   MeSH
• oleje rostlin farmakologie   MeSH
• proliferace buněk MeSH
• Check Tag
• lidé MeSH
• Publikační typ
• časopisecké články MeSH
• Názvy látek
• antiinfekční látky MeSH
• oleje prchavé MeSH
• oleje rostlin MeSH

Bacteria of the Arcobacter (A.) genus, originating mainly from food and water, are dreaded germs for humans as well as animals. However, the virulence of these bacteria has not been fully elucidated yet. This study looked at the occurrence of eight virulence-associated factors (ciaB, cj1349, pldA, irgA, hecA, tlyA, mviN, hecB) in a total of 80 isolates of Arcobacter butzleri and 22 isolates of A. cryaerophilus. The isolates were derived from food, water, and clinical samples. A polymerase chain reaction using specific primers was used to detect these virulence-associated genes. The presence of all genes in the isolates of A. butzleri (98.8% ciaB, 95.0% cj1349, 98.8% pldA, 22.5% irgA, 31.3% hecA, 95.0% tlyA, 97.5% mviN, 38.8% hecB) and A. cryaerophilus (95.5% ciaB, 0.0% cj1349, 9.1% pldA, 0.0% irgA, 0.0% hecA, 31.8% tlyA, 90.9% mviN, 0.0% hecB) was monitored. Among the tested isolates, there were 13 isolates (12.7%) of A. butzleri, in which the presence of all eight virulence-associated genes was recorded in the genome. In contrast, in one A. cryaerophilus strain, none of the observed genes were detected. The presence of ciaB and mviN genes was significantly more frequent in A. cryaerophilus isolates than other genes (P < 0.05). In general, more virulence-associated genes have been detected in A. butzleri isolates compared to A. cryaerophilus. The most common gene combination (ciaB, cj1349, pldA, tlyA, mviN) was detected in case of 39 isolates. In 50.0% of A. butzleri isolates derived from clinical samples, all eight virulence-associated genes were significantly more frequently detected (P < 0.05). The tlyA gene occurred significantly more frequent in A. butzleri isolates from meat and water samples and irgA and hecB genes in clinical samples. Therefore, our study provides information about occurrence of virulence-associated genes in genome of Arcobacter isolates. These findings could be hazardous to human health, because the presence of virulence-associated genes is the assumption for potential dangerousness of these bacteria. Our results indicate high incidence of virulence-associated genes in Arcobacter genomes and hence potentially pathogenic properties of the studied strains.

• MeSH
• Arcobacter genetika   izolace a purifikace   patogenita   MeSH
• bakteriální geny genetika   MeSH
• faktory virulence genetika   MeSH
• genetická variace MeSH
• gramnegativní bakteriální infekce mikrobiologie   MeSH
• mikrobiologie vody * MeSH
• potravinářská mikrobiologie * MeSH
• Publikační typ
• časopisecké články MeSH
• Geografické názvy
• Česká republika MeSH
• Názvy látek
• faktory virulence MeSH

This study provides information on the occurrence of Arcobacter in several types of water and food products of animal origin in the Czech Republic. We processed 190 samples using the modified method, and the occurrence of Arcobacter spp. was confirmed in 36.8 % of these. This total incidence consisted of Arcobacter butzleri (27.3 %), Arcobacter cryaerophilus (8.4 %) and Arcobacter skirrowii (1.1 %). We newly described the common presence of Arcobacter spp. in sewage water in the Czech Republic that is released into waterways after processing in water treatment plants (86.7 %). All the acquired isolates were subject to detailed confirmation with subsequent species classification using multiplex PCR and matrix-assisted laser desorption/ionization time-of-flight mass spectrometry (MALDI-TOF MS). In this study, we used a modification of a method using passive filtration of an enriched sample, which could be suitable for the isolation of Arcobacter, especially in combination with Campylobacter selective agar chromogenic medium. Our studies have shown this agar to be quite suited to the isolation of Arcobacter and that it can be an appropriate instrument for accelerating culture diagnostics.

• MeSH
• Arcobacter genetika   růst a vývoj   izolace a purifikace   metabolismus   MeSH
• kultivační média metabolismus   MeSH
• odpadní vody mikrobiologie   MeSH
• počet mikrobiálních kolonií přístrojové vybavení   metody   MeSH
• potravinářská mikrobiologie * MeSH
• Publikační typ
• časopisecké články MeSH
• hodnotící studie MeSH
• práce podpořená grantem MeSH
• Geografické názvy
• Česká republika MeSH
• Názvy látek
• kultivační média MeSH
• odpadní vody MeSH