Mycotoxins have been widely studied by many research groups but further multidisciplinary research is needed to better understand and clarify many issues. This study describes the use of high-performance liquid chromatography coupled with ion trap mass spectrometry (HPLC-MS) to measure T-2 toxin and its metabolites, such as HT-2 toxin, neosolaniol (NEO) and diacetoxyscirpenol (DAS), as well as masked glucosylated mycotoxins in Fusarium-infected Czech spring barley. In total, 152 spring barley samples from the 2018 harvest were analyzed by the ELISA screening method for the presence of T-2 toxin. The most contaminated samples (15), which exceeded the recommended maximum level set by the EU for the sum of T-2 and HT-2 toxin in unprocessed cereals (200 μg/kg), were analyzed by HPLC-MS/MS and microbiological testing. Isolated fungi were evaluated microscopically and identified by polymerase chain reaction (PCR) assays. The prevalence of Fusarium species in spring barley across the Czech Republic in 2018 showed a predominance of F. poae (12 barley samples) and F. tricinctum (9 barley samples). Other strains (F. sporotrichioides and F. langsethiae) were present at a lower frequency, in 1 and 2 samples, respectively. The average concentration of T-2 plus HT-2 toxin was 107.7 μg/kg, while NEO and DAS were found in a few samples at values close to their limit of quantification. HT-2 glucoside was identified in all samples.

• MeSH
• Fusarium * genetika   MeSH
• ječmen (rod) * mikrobiologie   MeSH
• jedlá semena mikrobiologie   MeSH
• kontaminace potravin analýza   MeSH
• T-2 toxin * analýza   MeSH
• tandemová hmotnostní spektrometrie MeSH
• Publikační typ
• časopisecké články MeSH
• Geografické názvy
• Česká republika MeSH

Tyramine is one of the most toxic biogenic amines and it is produced commonly by lactic acid bacteria in fermented food products. In present study, we investigated the influence of selected nisin-producing Lactococcus lactis subsp. lactis strains and their cell-free supernatants (CFSs) on tyramine production by four Lactobacillus and two Lactiplantibacillus strains isolated from cheese and beer. Firstly, we examined the antimicrobial effect of the CFSs from twelve Lactococcus strains against tested tyramine producers by agar-well diffusion assay. Six Lactococcus strains whose CFSs showed the highest antimicrobial effect on tyramine producers were further studied. Secondly, we investigated the influence of the selected six Lactococcus strains and their respective CFSs on tyramine production by tested Lactobacillus and Lactiplantibacillus strains in MRS broth supplemented with 2 g.L-1 of l-tyrosine. Tyramine production was monitored by HPLC-UV. The tyramine formation of all tested Lactobacillus and Lactiplantibacillus strains was not detected in the presence of Lc. lactis subsp. lactis CCDM 71 and CCDM 702, and their CFSs. Moreover, the remainder of the investigated Lactococcus strains (CCDM 670, CCDM 686, CCDM 689 and CCDM 731) and their CFSs decreased tyramine production significantly (P < 0.05) - even suppressing it completely in some cases - in four of the six tested tyramine producing strains.

• MeSH
• antibakteriální látky analýza   metabolismus   farmakologie   MeSH
• kultivační média chemie   metabolismus   farmakologie   MeSH
• Lactobacillaceae účinky léků   růst a vývoj   izolace a purifikace   MeSH
• Lactobacillus účinky léků   růst a vývoj   izolace a purifikace   MeSH
• Lactococcus lactis chemie   metabolismus   MeSH
• pivo mikrobiologie   MeSH
• sýr mikrobiologie   MeSH
• tyramin analýza   metabolismus   farmakologie   MeSH
• vysokoúčinná kapalinová chromatografie MeSH
• Publikační typ
• časopisecké články MeSH

Strains of Limosilactobacillus reuteri are used as starter and bioprotective cultures and contribute to the preservation of food through the production of fermentation metabolites lactic and acetic acid, and of the antimicrobial reuterin. Reuterin consists of acrolein and 3-hydroxypropionaldehyde (3-HPA), which can be further metabolized to 1,3-propanediol and 3-hydroxypropionic acid (3-HP). While reuterin has been the focus of many investigations, the contribution of 3-HP to the antimicrobial activity of food related reuterin-producers is unknown. We show that the antibacterial activity of 3-HP was stronger at pH 4.8 compared to pH 5.5 and 6.6. Gram-positive bacteria were in general more resistant against 3-HP and propionic acid than Gram-negative indicator strains including common food pathogens, while spoilage yeast and molds were not inhibited by ≤ 640 mM 3-HP. The presence of acrolein decreased the minimal inhibitory activity of 3-HP against E. coli indicating synergistic antibacterial activity. 3-HP was formed during the growth of the reuterin-producers, and by resting cells of L. reuteri DSM 20016. Taken together, this study shows that food-related reuterin producers strains synthesize a second antibacterial compound, which might be of relevance when strains are added as starter or bioprotective cultures to food products.

• MeSH
• antiinfekční látky chemie   metabolismus   farmakologie   MeSH
• Bacteria účinky léků   růst a vývoj   MeSH
• fermentace MeSH
• glyceraldehyd analogy a deriváty   chemie   metabolismus   MeSH
• glycerol metabolismus   MeSH
• koncentrace vodíkových iontů MeSH
• kyselina mléčná analogy a deriváty   chemie   metabolismus   farmakologie   MeSH
• kyselina octová metabolismus   MeSH
• Lactobacillaceae chemie   růst a vývoj   metabolismus   MeSH
• potravinářská mikrobiologie MeSH
• propan chemie   metabolismus   MeSH
• stabilita léku MeSH
• Publikační typ
• časopisecké články MeSH

Degradation of undesirable biogenic amines (BAs) in foodstuffs by microorganisms is considered one of the most effective ways of eliminating their toxicity. In this study, we designed two sets of primers for the detection and quantification of the multicopper oxidase gene (MCO), which encodes an enzyme involved in BAs degradation, and endogenous (glyceraldehyde-3-phosphate dehydrogenase) gene (GAPDH) in Lactobacillus casei group by real-time PCR (qPCR). We tested 15 Lactobacillus strains in the screening assays (thus, MCO gene possessing assay (PCR) and monitoring of BAs degradation by HPLC-UV), in which Lactobacillus casei CCDM 198 exhibited the best degradation abilities. For this strain, we monitored the expression of the target gene (MCO) in time (qPCR), the effect of redox treatments (cysteine, ascorbic acid) on the expression of the gene, and the ability to degrade BAs not only in a modified MRS medium (MRS/2) but also in a real food sample (milk). Moreover, decarboxylase activity (ability to form BAs) of this strain was excluded. According to the results, CCDM 198 significantly (P < 0.05) reduced BAs (putrescine, histamine, tyramine, cadaverine), up to 25% decline in 48 h. The highest level of relative expression of MCO (5.21 ± 0.14) was achieved in MRS/2 media with cysteine.

• MeSH
• bakteriální proteiny genetika   metabolismus   MeSH
• biogenní aminy analýza   metabolismus   MeSH
• cystein analýza   metabolismus   MeSH
• glyceraldehyd-3-fosfátdehydrogenasy genetika   MeSH
• kultivační média chemie   MeSH
• kvantitativní polymerázová řetězová reakce MeSH
• kyselina askorbová analýza   metabolismus   MeSH
• Lactobacillus casei enzymologie   genetika   růst a vývoj   metabolismus   MeSH
• Lactobacillus enzymologie   genetika   růst a vývoj   metabolismus   MeSH
• mléko chemie   MeSH
• oxidoreduktasy genetika   metabolismus   MeSH
• regulace genové exprese u bakterií MeSH
• vysokoúčinná kapalinová chromatografie MeSH
• zvířata MeSH
• Check Tag
• zvířata MeSH
• Publikační typ
• časopisecké články MeSH

The present pilot study aimed at evaluating air sampling as a novel method for monitoring Campylobacter in poultry farms. We compared the bacteriological isolation of Campylobacter from boot swabs and air filter samples using ISO 10272-1:2017. A secondary aim was to evaluate the use of molecular methods, i.e. real time PCR, on the same sample set. Samples from 44 flocks from five European countries were collected, and included air samples, in parallel with boot swabs. Campylobacter spp. was isolated from seven of 44 boot swabs from three of five partners using the enrichment method. Two of these positive boot swab samples had corresponding positive air samples. Using enrichment, one positive air sample was negative in the corresponding boot swabs, but Campylobacter spp. was isolated from direct plating of the boot swab sample. One partner isolated Campylobacter spp. from six of 10 boot swabs using direct plating. Overall, 33 air filter samples were screened directly with PCR, returning 14 positive results. In conclusion, there was a lack of correspondence between results from analysis of boot swabs and air filters using ISO 10272-1:2017. In contrast, the combination of air filters and direct real-time PCR might be a way forward. Despite the use of the detailed ISO protocols, there were still sections that could be interpreted differently among laboratories. Air sampling may turn into a multi-purpose and low-cost sampling method that may be integrated into self-monitoring programs.

• MeSH
• Campylobacter genetika   izolace a purifikace   MeSH
• drůbež mikrobiologie   MeSH
• farmy statistika a číselné údaje   MeSH
• feces mikrobiologie   MeSH
• internacionalita MeSH
• kampylobakterové infekce veterinární   MeSH
• kur domácí mikrobiologie   MeSH
• mikrobiologie vzduchu normy   MeSH
• nemoci drůbeže mikrobiologie   prevence a kontrola   přenos   MeSH
• pilotní projekty MeSH
• zvířata MeSH
• Check Tag
• zvířata MeSH
• Publikační typ
• časopisecké články MeSH
• hodnotící studie MeSH
• multicentrická studie MeSH
• Geografické názvy
• Evropa MeSH

Food of non-animal origin is a major component of the human diet and has been considered to pose a low risk from the point of view of bacteriological safety. However, an increase in the number of outbreaks of illness caused by such pathogens and linked to the consumption of fresh fruit and vegetables have been reported from around the world recently. Salmonella spp., STEC (Shiga toxin producing Escherichia coli) and Listeria monocytogenes are among the most frequently identified agents. Additionally, the transmission of antibiotic resistant strains including also the methicillin resistant S. aureus (MRSA) to humans via the food chain is one of the greatest public health problems being confronted today. Therefore, we focused on the bacterial safety of fruit, vegetables and sprouts on sale in the Czech Republic. One strain (0.3%) of Salmonella Enteritidis phage type PT8, one strain (0.3%) of MRSA and 17 strains (5.0%) of L. monocytogenes were isolated from a total of 339 collected samples. The most problematic commodities were frozen fruit and vegetables (packed and unpacked) and fresh-cut vegetables. Our findings indicate deficiencies in hygiene practices during harvesting, processing and distribution of these commodities. Although sprouts and berries are the most likely to be contaminated by human pathogens, only two samples were positive for the presence of L. monocytogenes.

• MeSH
• Bacteria izolace a purifikace   MeSH
• bezpečnost potravin * MeSH
• Escherichia coli O157 izolace a purifikace   MeSH
• lidé MeSH
• Listeria monocytogenes izolace a purifikace   MeSH
• methicilin rezistentní Staphylococcus aureus izolace a purifikace   MeSH
• ovoce mikrobiologie   MeSH
• počet mikrobiálních kolonií MeSH
• polymerázová řetězová reakce MeSH
• potravinářská mikrobiologie MeSH
• Salmonella enteritidis izolace a purifikace   MeSH
• semenáček mikrobiologie   MeSH
• shiga-toxigenní Escherichia coli izolace a purifikace   MeSH
• techniky typizace bakterií MeSH
• zelenina mikrobiologie   MeSH
• Check Tag
• lidé MeSH
• Publikační typ
• časopisecké články MeSH
• Geografické názvy
• Česká republika MeSH

Bacteria from the genus Cronobacter are opportunistic foodborne pathogens that can cause severe infections. More rapid, cost-effective and reliable methods are still required for the species identification of Cronobacter spp. In this study, we present a novel PCR-RFLP-based method that uses a newly designed pair of primers for the PCR-amplification of a partial rpoB gene sequence (1635 bp). The amplified products of DNA from 80 Cronobacter strains were separately digested with three restriction endonucleases (Csp6I, HinP1I, MboI). Using the obtained restriction patterns, a PCR-RFLP identification system was created to enable differentiation between all seven currently-known Cronobacter species. The functionality of our method was successfully verified on real food samples. Moreover, the relationships between the Cronobacter species were determined via a phylogenetic tree created from the RFLP patterns.

• MeSH
• bakteriální geny * MeSH
• Cronobacter klasifikace   genetika   MeSH
• DNA bakterií MeSH
• DNA primery MeSH
• DNA řízené RNA-polymerasy genetika   MeSH
• fylogeneze MeSH
• kontaminace potravin analýza   MeSH
• polymerázová řetězová reakce ekonomika   metody   MeSH
• polymorfismus délky restrikčních fragmentů * MeSH
• potravinářská mikrobiologie * MeSH
• restrikční endonukleasy typu II metabolismus   MeSH
• sekvenční analýza DNA MeSH
• Publikační typ
• časopisecké články MeSH

Undercooked lamb and mutton are common sources of Toxoplasma gondii infection for humans. A sequence specific magnetic capture technique in combination with quantitative real-time PCR targeting the 529 bp repeat element of T. gondii was used for estimation of the parasite burdens in various sheep tissues (n = 6) three months after peroral experimental inoculation with 10,000 T. gondii oocysts. Brain was the most frequently affected organ (positive in all 6 sheep) and showed the highest estimated parasite loads (0.5-30,913 parasites/g tissue). Lung samples were positive in three sheep, with load estimates of 36.3 to <1 parasite/g tissue. Heart tissue was positive in three sheep and kidney only in one animal with low parasite loads (<1 parasite/g tissue). Only few skeletal muscle samples in 2 animals showed positive results, with very low parasite burdens, while samples from further internal organs (i.e. liver and spleen) were negative in all animals. This study identified the brain as the most important predilection site and therefore the most appropriate tissue for T. gondii detection.

• MeSH
• anatomické struktury zvířat parazitologie   MeSH
• kvantitativní polymerázová řetězová reakce přístrojové vybavení   metody   MeSH
• magnetismus MeSH
• ovce MeSH
• Toxoplasma genetika   izolace a purifikace   MeSH
• toxoplazmóza zvířat parazitologie   MeSH
• zvířata MeSH
• Check Tag
• zvířata MeSH
• Publikační typ
• časopisecké články MeSH
• práce podpořená grantem MeSH

Ingestion of raw or undercooked meat is a potential source of human toxoplasmosis. The aim of this study was to determine the viability of Toxoplasma gondii cysts in vacuum packed (VP) goat meat and in dry fermented sausages (DFS), and evaluate certain physical and chemical parameters, like water activity (aw), pH value, content of salt, dry matter and fat. A portion of muscle tissue from experimentally infected animals was used for production of VP meat with or without addition of 2.5% curing salt, and stored at 4 °C or at -20 °C. Results of bioassay showed that, samples of vacuum packed Toxoplasma positive meat without salt addition were alive after six weeks at 4 °C. Incubation at -20 °C supported the viability after 3 h, but not after 4 h. After 7 days in 2.5% of curing salt, samples of T. gondii VP goat meat were still viable, but not after 14 days at 4 °C. All the DFS samples were not positive for infective cysts which mean that, they do not pose a risk of T. gondii transmission. These data suggest that vacuum packaging increases the survival of T. gondii cysts.

• MeSH
• kosterní svaly parazitologie   MeSH
• kozy MeSH
• lidé MeSH
• masné výrobky analýza   parazitologie   MeSH
• maso analýza   parazitologie   MeSH
• nemoci koz parazitologie   MeSH
• obaly potravin MeSH
• spotřebitelská bezpečnost produktů MeSH
• Toxoplasma genetika   růst a vývoj   izolace a purifikace   MeSH
• toxoplazmóza zvířat parazitologie   MeSH
• vakuum MeSH
• zvířata MeSH
• Check Tag
• lidé MeSH
• zvířata MeSH
• Publikační typ
• časopisecké články MeSH
• práce podpořená grantem MeSH

Pigs represent an important source of food in many countries, and undercooked pork containing tissue cysts is one of the most common sources of Toxoplasma gondii infection for humans. A magnetic capture method for the isolation of T. gondii DNA and quantitative real-time PCR targeting the 529 bp TOXO repeat element were used to estimate the parasite burden in different tissues of pigs experimentally infected with T. gondii oocysts, and to determine the predilection sites of T. gondii in this host species. The highest concentration of T. gondii DNA was found in brain tissues, equivalent to [median] 553.7 (range 3857.7-121.9) parasites per gram, followed by lungs, heart and dorsal muscles with median values corresponding to 0.3 (range 61.3-0.02); 2.6 (range 7.34-0.37) and 0.6 (range 2.81-0.31) parasites per gram of tissue, respectively. Skeletal muscles from fore and hindlimb, liver and kidney presented very low infection burdens equivalent to [median] ≤0.2 parasites per gram of tissues, and no parasite DNA could be detected in the spleen. This study contributes to understanding the value of different pig tissues as a source of T. gondii infection for humans and shows that the brain, while not being of major importance as human food source, may represent a first-line selection tissue when performing non-serological surveys (e.g. bioassays, histopathological, immunohistochemical or molecular studies) to detect T. gondii infections in pigs.

• MeSH
• kvantitativní polymerázová řetězová reakce metody   MeSH
• magnetismus metody   MeSH
• mozek parazitologie   patologie   MeSH
• nemoci prasat parazitologie   patologie   MeSH
• prasata MeSH
• Toxoplasma chemie   genetika   izolace a purifikace   fyziologie   MeSH
• toxoplazmóza zvířat parazitologie   patologie   MeSH
• zvířata MeSH
• Check Tag
• zvířata MeSH
• Publikační typ
• časopisecké články MeSH
• práce podpořená grantem MeSH