Enterotoxigenic Escherichia coli (ETEC) and Shiga toxin-producing E. coli (STEC) strains are the causative agents of severe foodborne diseases in both humans and animals. In this study, porcine pathogenic E. coli strains (n = 277) as well as porcine commensal strains (n = 188) were tested for their susceptibilities to 34 bacteriocin monoproducers to identify the most suitable bacteriocin types inhibiting porcine pathogens. Under in vitro conditions, the set of pathogenic E. coli strains was found to be significantly more susceptible to the majority of tested bacteriocins than commensal E. coli. Based on the production of bacteriocins with specific activity against pathogens, three potentially probiotic commensal E. coli strains of human origin were selected. These strains were found to be able to outcompete ETEC strains expressing F4 or F18 fimbriae in liquid culture and also decreased the severity and duration of diarrhea in piglets during experimental ETEC infection as well as pathogen numbers on the last day of in vivo experimentation. While the extents of the probiotic effect were different for each strain, the cocktail of all three strains showed the most pronounced beneficial effects, suggesting synergy between the tested E. coli strains. IMPORTANCE Increasing levels of antibiotic resistance among bacteria also increase the need for alternatives to conventional antibiotic treatment. Pathogenic Escherichia coli represents a major diarrheic infectious agent of piglets in their postweaning period; however, available measures to control these infections are limited. This study describes three novel E. coli strains producing antimicrobial compounds (bacteriocins) that actively inhibit a majority of toxigenic E. coli strains. The beneficial effect of three potentially probiotic E. coli strains was demonstrated under both in vitro and in vivo conditions. The novel probiotic candidates may be used as prophylaxis during piglets' postweaning period to overcome common infections caused by E. coli.

• MeSH
• bakteriální toxiny * metabolismus   MeSH
• bakteriociny metabolismus   terapeutické užití   MeSH
• Escherichia coli * účinky léků   genetika   metabolismus   MeSH
• faktory virulence genetika   MeSH
• feces mikrobiologie   MeSH
• infekce vyvolané Escherichia coli mikrobiologie   prevence a kontrola   veterinární   MeSH
• nemoci prasat mikrobiologie   prevence a kontrola   MeSH
• prasata MeSH
• probiotika terapeutické užití   MeSH
• zvířata MeSH
• Check Tag
• zvířata MeSH
• Publikační typ
• časopisecké články MeSH
• práce podpořená grantem MeSH
• randomizované kontrolované studie veterinární MeSH

This study was focused on characterization of the genetic diversity of Listeria monocytogenes isolated from packed fresh rabbit meat obtained from one producer via retail outlets. The partial aim was to compare the characteristics of a suspect persistent strain with strains from human cases. The occurrence of L. monocytogenes in vacuum-packed rabbit meat was monitored during 2013 to 2016. All strains were characterized by serotyping, pulsed-field gel electrophoresis, and multilocus sequence typing (MLST). Selected strains, which represented each year, were analyzed using the whole genome sequencing method. L. monocytogenes was detected in 21 (38%) of 56 originally packed rabbit meat samples from one food producer during the whole monitored period. All strains showed the identical serotype (1/2a), AscI/ApaI pulsotype (735/2), and sequence type (ST451). The clonal similarity of strains from rabbit meat was also confirmed on the basis of core genome MLST (on 1,701 loci). This fact suggests the occurrence of a suspect persistent strain in the meat processing plant. Results of core genome MLST enabled us to unambiguously exclude rabbit meat as a source of listeriosis in humans caused by the indistinguishable AscI/ApaI pulsotype and sequence type, although all strains carried all genes important for the virulence of L. monocytogenes. No specific genes that may be associated with its persistence in the food processing environment were detected among the tested strains of ST451.

• MeSH
• genetická variace MeSH
• králíci mikrobiologie   MeSH
• lidé MeSH
• Listeria monocytogenes * genetika   MeSH
• listeriové infekce * mikrobiologie   přenos   MeSH
• maso * mikrobiologie   MeSH
• multilokusová sekvenční typizace MeSH
• potravinářská mikrobiologie * MeSH
• pulzní gelová elektroforéza MeSH
• sérotypizace MeSH
• zvířata MeSH
• Check Tag
• králíci mikrobiologie   MeSH
• lidé MeSH
• zvířata MeSH
• Publikační typ
• časopisecké články MeSH
• Geografické názvy
• Česká republika MeSH

• MeSH
• lidé MeSH
• Listeria monocytogenes * cytologie   izolace a purifikace   MeSH
• listeriové infekce mikrobiologie   MeSH
• multilokusová sekvenční typizace metody   MeSH
• potravinářská mikrobiologie metody   MeSH
• průmyslově zpracované potraviny mikrobiologie   MeSH
• sérotypizace metody   MeSH
• Check Tag
• lidé MeSH
• Publikační typ
• práce podpořená grantem MeSH
• Geografické názvy
• Česká republika MeSH

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

Listeria monocytogenes je původcem závažného alimentárního onemocnění s vysokou mírou mortality. Cílem této práce bylo posoudit pomocí molekulárně biologických metod diverzitu humánních izolátů L. monocytogenes v České republice v letech 2013–2016. Většina listerióz byla vyvolána kmeny sérotypu 1/2a (58 %) klonálního komplexu CC8 (28 %) a sérotypu 4b (28 %) komplexu CC6 (16 %). Výsledky makrorestrikční analýzy potvrdily výskyt zejména sporadických případů listerióz. Zvýšený počet případů listerióz v Moravskoslezském kraji byl způsoben epidemií lokálního charakteru. Pro šetření epidemií listerióz se osvědčilo použití molekulárních subtypizačních metod v reálném čase.

Listeria monocytogenes is the cause of a serious foodborne infection with a high fatality rate. The aim of this study was to assess the diversity of human isolates of L. monocytogenes recovered in the Czech Republic from 2013 to 2016 by molecular biological methods. Most cases of listeriosis were caused by strains of serotype 1/2a (58 %) from clonal complex CC8 (28 %) and serotype 4b (28 %) from CC6 (16 %). The results of macrorestriction analysis confirmed primarily the occurrence of sporadic cases of listeriosis. A local outbreak of listeriosis was reported in the Moravian-Silesian Region. Real-time molecular subtyping methods have proved helpful in the investigation of Listeria outbreaks.

• Klíčová slova
• klonální komplex,
• MeSH
• incidence MeSH
• lidé MeSH
• Listeria monocytogenes * klasifikace   patogenita   MeSH
• listeriové infekce MeSH
• molekulární epidemiologie MeSH
• séroskupina MeSH
• sérotypizace MeSH
• Check Tag
• lidé MeSH
• Publikační typ
• práce podpořená grantem MeSH
• Geografické názvy
• Česká republika MeSH

• MeSH
• analýza potravin * metody   MeSH
• Listeria monocytogenes * izolace a purifikace   MeSH
• polymerázová řetězová reakce MeSH
• potravinářská mikrobiologie MeSH
• průzkumy a dotazníky MeSH
• sérotypizace MeSH
• skladování potravin MeSH
• sýr mikrobiologie   MeSH
• Publikační typ
• práce podpořená grantem MeSH
• Geografické názvy
• Česká republika MeSH

• MeSH
• hospodářská zvířata MeSH
• kojenec MeSH
• lidé MeSH
• plazi MeSH
• přenos infekční nemoci MeSH
• salmonelóza * diagnóza   farmakoterapie   přenos   MeSH
• výsledek terapie MeSH
• zoonózy * diagnóza   farmakoterapie   přenos   MeSH
• zvířata MeSH
• Check Tag
• kojenec MeSH
• lidé MeSH
• mužské pohlaví MeSH
• zvířata MeSH
• Publikační typ
• kazuistiky MeSH
• práce podpořená grantem MeSH