The alarming occurrence of antibiotic resistance genes in food production demands continuous monitoring worldwide. One reservoir of resistance genes is thought to be eDNA. There is currently little available information in Europe about either the extracellular DNA distribution of the bacterium or the spread of resistance genes in L. monocytogenes. Therefore, our aims were to give insight into the Listeria monocytogenes resistance situation in the Czech Republic and assess the presence of resistance genes in their extracellular DNA (eDNA). First, susceptibility tests were performed on 49 isolates of L. monocytogenes with selected antibiotics. Next, we tested DNA of suspected isolates for the presence of resistance genes in both planktonic cells and the eDNA of biofilms. Finally, fluorescent confocal microscopy was used to observe the eDNA pattern of selected isolates under conditions that mimicked the food processing environment and the human body. Susceptibility tests found isolates intermediate resistant to chloramphenicol, tetracycline, and ciprofloxacin as well as isolates resistant to ciprofloxacin. For all suspected isolates, PCR confirmed the presence of the gene lde encoding efflux pump in both types of DNA. When the biofilm was observed using confocal laser scanning microscope, the eDNA distribution patterns varied considerably according to the culture conditions. Furthermore, the food and clinical isolates varied in terms of the amount of eDNA detected. The presence of an efflux pump in both types of DNA suggests that the eDNA might serve as a reservoir of resistance genes. Surprising differences were observed in the eDNA pattern. Our results suggest that the current risk of the spread of L. monocytogenes resistance genes is low in the Czech Republic, but they also indicate the need for continuous long-term monitoring of the situation.

• MeSH
• antibakteriální látky farmakologie   MeSH
• bakteriální geny genetika   MeSH
• bakteriální léková rezistence genetika   MeSH
• biofilmy * MeSH
• DNA bakterií genetika   metabolismus   MeSH
• extracelulární prostor genetika   MeSH
• lidé MeSH
• Listeria monocytogenes účinky léků   genetika   růst a vývoj   izolace a purifikace   MeSH
• mikrobiální testy citlivosti MeSH
• mikrobiální viabilita účinky léků   MeSH
• potravinářská mikrobiologie MeSH
• shluková analýza MeSH
• Check Tag
• lidé MeSH
• Publikační typ
• časopisecké články MeSH
• Geografické názvy
• Česká republika MeSH
• Názvy látek
• antibakteriální látky MeSH
• DNA bakterií MeSH

Since 2012-2016 an increased number of listeriosis cases, especially from one region of the Czech Republic, were observed. Most of them were caused by strains of serotype 1/2a, clonal complex 8, indistinguishable by pulsed-field gel electrophoresis. Twenty-six human cases were reported, including two neonatal cases in twins. Three cases were fatal. The typing of Listeria monocytogenes isolates from food enabled to confirm a turkey meat delicatessen as the vehicle of infection for this local outbreak in the Moravian-Silesian Region. The food strains belonging to identical pulsotype were isolated from ready-to-eat turkey meat products packaged by the same producer between 2012 and 2016. This fact confirms that the described L. monocytogenes outbreak strain probably persisted in the environment of the aforementioned food-processing plant over several years. Whole-genome sequencing confirmed a very close relationship (zero to seven different alleles) between isolates from humans, foods and swabs from the environment of the food-processing plant under investigation.

• Klíčová slova
• Listeria monocytogenes, molecular epidemiology, whole-genome sequencing,
• MeSH
• aglutinační testy MeSH
• dítě MeSH
• dospělí MeSH
• epidemický výskyt choroby * MeSH
• incidence MeSH
• kojenec MeSH
• krocani mikrobiologie   MeSH
• lidé středního věku MeSH
• lidé MeSH
• Listeria monocytogenes klasifikace   genetika   MeSH
• listeriové infekce epidemiologie   etiologie   MeSH
• masné výrobky mikrobiologie   MeSH
• mladiství MeSH
• mladý dospělý MeSH
• multilokusová sekvenční typizace MeSH
• multiplexová polymerázová řetězová reakce MeSH
• předškolní dítě MeSH
• restrikční mapování MeSH
• sekvenování celého genomu MeSH
• senioři MeSH
• sérotypizace MeSH
• zvířata MeSH
• Check Tag
• dítě MeSH
• dospělí MeSH
• kojenec MeSH
• lidé středního věku MeSH
• lidé MeSH
• mladiství MeSH
• mladý dospělý MeSH
• mužské pohlaví MeSH
• předškolní dítě MeSH
• senioři MeSH
• ženské pohlaví MeSH
• zvířata MeSH
• Publikační typ
• časopisecké články MeSH
• práce podpořená grantem MeSH
• Geografické názvy
• Česká republika epidemiologie   MeSH