Cíl práce: Cílem studie bylo určit genetickou rozmanitost humánních izolátů získaných v letech 2016–2020 z klinických laboratoří z různých lokalit České republiky (ČR) s ohledem na možné epidemické souvislosti a virulenci Listeria monocytogenes za využití dat celogenomového sekvenování. Metody: Ve studii byl použit soubor 102 humánních izolátů L. monocytogenes, u kterých byl určen sérotyp sklíčkovou aglutinací v kombinaci s multiplex PCR sérotypizací. Retrospektivně bylo provedeno celogenomové sekvenování a na základě získaných dat byla posouzena klonální příbuznost testovaných kmenů a přítomnost genů virulence pomocí softwaru Ridom SeqSphere+. Výsledky: V období let 2016–2020 bylo celkem charakterizováno 102 humánních izolátů L. monocytogenes, což činí 65 % ze všech hlášených případů listerióz registrovaných ve sledovaném období v ČR v systémech ISIN/EPIDAT. Dominantní zastoupení měl sérotyp 1/2a (57 %), následoval sérotyp 4b (30 %) a jen ojediněle byly detekovány kmeny sérotypu 1/2b (12 %) a 1/2c (1 %). Na základě analýzy celogenomových dat byly kmeny zařazeny k 26 klonálním komplexům a 27 sekvenačním typům. Porovnáním cgMLST (core genome Multi-Locus Sequence Typing) byly detekovány čtyři klastry o více jak třech kmenech vykazující vysokou příbuznost (rozdíly do 10 alel) s možnou epidemickou souvislostí. U všech kmenů byla potvrzena přítomnost klíčových genů virulence. Pouze u tří kmenů (sérotypu 1/2a, 1/2b a 1/2c) byla detekována bodová mutace v genu inlA spojovaná s expresí zkráceného proteinu internalinu A, který je zapojený do mechanismu přestupu L. monocytogenes intestinální bariérou. Závěr: Molekulární epidemiologie založená na celogenomovém sekvenování představuje účinný nástroj ke studiu populační struktury kmenů L. monocytogenes. V této studii byla zjištěna vysoká heterogenita humánních kmenů L. monocytogenes, zejména u v České republice dominantního sérotypu 1/2a. Bylo identifikováno několik klastrů s možnou epidemickou souvislostí, jejichž výskyt bude dále sledován.
Study aim: To determine the genetic diversity of human isolates of Listeria monocytogenes obtained in 2016–2020 from clinical laboratories in various locations of the Czech Republic with a focus on their possible epidemic links and virulence using whole genome sequencing data. Methods: A total of 102 human L. monocytogenes isolates, serotyped by slide agglutination in combination with multiplex PCR serotyping, were used in this study. Whole genome sequencing was performed retrospectively, and based on the obtained data, the clonal relatedness of the tested strains and the presence of virulence genes were assessed using the Ridom SeqSphere+ software. Results: In 2016-2020, 102 human isolates of L. monocytogenes were characterized, which represented 65% of all cases of listeriosis reported to the ISIN/EPIDAT systems in the Czech Republic in the monitored period. Serotype 1/2a (57%) was dominant, followed by serotype 4b (30%). Strains of serotype 1/2b (12%) and 1/2c (1%) were rarely detected. Based on the analysis of whole genome sequencing data, the strains were assigned to 26 clonal complexes and 27 sequence types. The cgMLST (core genome Multi-Locus Sequence Typing) analysis revealed four clusters of more than three strains, showing high relatedness (differences up to 10 alleles) with a possible epidemic link. The presence of all key virulence genes was confirmed in all strains. Only three strains (of serotypes 1/2a, 1/2b, and 1/2c) carried a point mutation in the inlA gene responsible for the expression of truncated internalin A protein, which is involved in the mechanism of intestinal barrier crossing by L. monocytogenes. Conclusion: Molecular epidemiology based on whole genome sequencing is an effective tool to study the population structure of L. monocytogenes strains. This study found high heterogeneity of human L. monocytogenes strains, especially for serotype 1/2a, dominant in the Czech Republic. Several clusters with a possible epidemic link have been identified, and their occurrence will be further monitored.
This study was aimed on the detection of methicillin resistant Staphylococcus aureus (MRSA) in different categories of retailed ready-to-eat (RTE) meat products from the Czech producers and determination of their genetic properties, antimicrobial resistance and virulence. In RTE meat products, 2% (4/181) of examined samples were MRSA positive. MRSA strains were detected only in durable fermented meat products made exclusively from pork meat. Detection of livestock-associated MRSA (LA-MRSA) clonal lineages (ST398 and ST4999), SCCmec cassette type V and tetracycline resistance indicate a source of contamination from raw pork. The study confirms the ability of these strains to survive the technological process rather than contamination of meat products from the food processing environment. MRSA strains did not carry any of the tested genes encoding staphylococcal enterotoxins or virulence genes (for Panton-Valentine leukocidin, exfoliative toxins A, B and toxic shock syndrome). Our results point out the spread of LA-MRSA through the meat processing chain.
- MeSH
- antibakteriální látky farmakologie MeSH
- dobytek MeSH
- masné výrobky * MeSH
- maso MeSH
- methicilin rezistentní Staphylococcus aureus * genetika MeSH
- mikrobiální testy citlivosti MeSH
- stafylokokové infekce * MeSH
- zvířata MeSH
- Check Tag
- zvířata MeSH
- Publikační typ
- časopisecké články MeSH
- Geografické názvy
- Česká republika MeSH
Listeria monocytogenes (Lm) is a ubiquitous bacterium that causes listeriosis, a serious foodborne illness. In the nature-to-human transmission route, Lm can prosper in various ecological niches. Soil and decaying organic matter are its primary reservoirs. Certain clonal complexes (CCs) are over-represented in food production and represent a challenge to food safety. To gain new understanding of Lm adaptation mechanisms in food, the genetic background of strains found in animals and environment should be investigated in comparison to that of food strains. Twenty-one partners, including food, environment, veterinary and public health laboratories, constructed a dataset of 1484 genomes originating from Lm strains collected in 19 European countries. This dataset encompasses a large number of CCs occurring worldwide, covers many diverse habitats and is balanced between ecological compartments and geographic regions. The dataset presented here will contribute to improve our understanding of Lm ecology and should aid in the surveillance of Lm. This dataset provides a basis for the discovery of the genetic traits underlying Lm adaptation to different ecological niches.
BACKGROUND: Travellers were recognized as a risk cohort that can be colonized by mcr-1-mediated colistin-resistant Enterobacteriaceae. We aimed to investigate the carriage of mcr-mediated colistin resistance in Enterobacteriaceae in Czech travellers or expatriates residing temporarily in the Czech Republic. METHODS: Between August 2018 and September 2019, the stool samples were cultured in enrichment broth. The enriched cultures were tested for the presence of the mcr-1-8 genes and inoculated onto selective agar with colistin. Colistin-resistant Enterobacteriaceae were tested for the presence of the mcr-1-8 genes; the mcr-positive isolates were characterised by whole genome sequencing. RESULTS: From the 177 stool samples, 15 colistin-resistant Enterobacteriaceae isolates were cultured (7.9%); two of the E. coli isolates carried the mcr-1 gene (1.1%). In the E. coli multilocus sequence type (ST) 156, the mcr-1 gene was located in an ISApl1-mcr-1-orf-ISApl1 (Tn6330) and incorporated into the chromosome; in the E. coli ST23 isolate, the mcr-1 gene was harboured by the plasmid IncX4. Both of the mcr-1 positive E. coli isolates were multidrug-resistant and one isolate was an extended-spectrum β-lactamase producer (blaCTX-M-27). CONCLUSION: Patients with an international travel history should be monitored for the carriage of the mcr-1 gene in order to prevent its dissemination into healthcare settings.
- MeSH
- antibakteriální látky farmakologie MeSH
- bakteriální léková rezistence genetika MeSH
- chromozomy MeSH
- Enterobacteriaceae genetika MeSH
- Escherichia coli genetika MeSH
- kolistin * farmakologie MeSH
- lidé MeSH
- mikrobiální testy citlivosti MeSH
- plazmidy genetika MeSH
- proteiny z Escherichia coli * genetika MeSH
- průřezové studie MeSH
- Check Tag
- lidé MeSH
- Publikační typ
- časopisecké články MeSH
- práce podpořená grantem MeSH
- Geografické názvy
- Česká republika MeSH
In August 2017, an increased incidence of Salmonella Bareilly was detected in the Czech Republic. An investigation was conducted with Slovakia to confirm the outbreak and identify the source. Probable outbreak cases were defined as cases with laboratory-confirmed S. Bareilly reported in either of the national surveillance systems, and/or the Czech and Slovak National Reference Laboratory databases from July 2017. Confirmed cases had the pulsed-field gel electrophoresis (PFGE) outbreak pulsotype or up to 5 alleles difference from outbreak cluster members by core genome multilocus sequence typing (cgMLST). PFGE and whole genome sequencing were used for isolate comparison. The same trawling questionnaire was used in both countries. By the end of October 2018, 325 cases were identified. Among 88 human S. Bareilly isolates analysed by PFGE, 82 (93%) shared an identical pulsotype; cgMLST of 17 S. Bareilly human isolates showed 1-2 allele difference. The trawling questionnaire excluded consumption of unusual or imported foods. In September 2018, an isolate closely related to the outbreak isolates was identified in a powdered egg product. A spray dryer was recognised as the contamination source and the production plant was closed. Using molecular typing methods, we detected a diffuse cross-border outbreak caused by S. Bareilly.
- MeSH
- epidemický výskyt choroby * MeSH
- genom bakteriální MeSH
- lidé MeSH
- multilokusová sekvenční typizace MeSH
- pulzní gelová elektroforéza MeSH
- Salmonella * genetika MeSH
- sekvenování celého genomu MeSH
- Check Tag
- lidé MeSH
- Publikační typ
- časopisecké články MeSH
- Geografické názvy
- Česká republika MeSH
- Slovenská republika MeSH
OBJECTIVES: This study aimed to detect and characterise methicillin-resistant Staphylococcus aureus (MRSA) from retail meat in the Czech Republic. METHODS: Isolates were identified by PCR detection of the S. aureus-specific fragment Sa442 and mecA gene. spa typing, MLST, detection of genes encoding staphylococcal enterotoxins, Panton-Valentine leukocidin (pvl), exfoliative toxins A and B (eta and etb), toxic shock syndrome toxin (tst) and staphylokinase (sak), detection of φSa3 prophage and antimicrobial susceptibility testing were performed. RESULTS: Of 65 raw meat samples examined (poultry, beef, pork and rabbit), 23 (35.4%) were positive for MRSA. Twelve positive samples originated from poultry (12/33; 36.4%), while the remaining eleven came from pork (9/9; 100%) and pork/beef mixed minced meat (2/5; 40.0%). Eight spa types belonging to five different sequence types (STs) were identified. ST398 was the most frequent (28/36; 77.8%), presenting spa types t011, t034, t2576, t4132, t588 and t899. Other livestock-associated MRSA STs (ST9-t899, ST5-t002, ST692-t8646 or the newly described ST4034-t899) were also sporadically identified. In seven isolates (19.4%), one or more staphylococcal enterotoxin genes were detected, with sea, seg and sei prevailing. Three isolates from turkey [ST398-t899 (n = 2) and ST398-t011] harboured the sak gene, and the latter also harboured the sea gene. Seven isolates from poultry harboured the φSa3 prophage and were resistant to tetracycline. CONCLUSION: Specific kinds of meat appear to be a possible source of MRSA, although the risk to humans is hard to define. Therefore, surveillance of MRSA in meat as well as hygienic practices should be improved.
- MeSH
- antibakteriální látky farmakologie MeSH
- králíci MeSH
- maso MeSH
- methicilin rezistentní Staphylococcus aureus * genetika MeSH
- multilokusová sekvenční typizace MeSH
- skot MeSH
- Staphylococcus aureus genetika MeSH
- zvířata MeSH
- Check Tag
- králíci MeSH
- skot MeSH
- zvířata MeSH
- Publikační typ
- časopisecké články MeSH
- práce podpořená grantem MeSH
Aquaculture systems are widely recognised as hotspots for horizontal gene transfer, and the need for screening for bacteria carrying antimicrobial resistance genes in aquaculture systems is becoming more important. In this study, we characterised seventeen bacterial strains (Escherichia coli, Klebsiella pneumoniae, Acinetobacter baumannii, and A. nosocomialis) resistant to colistin originating from retailed aquaculture products imported from Vietnam to the Czech Republic. The mcr-1.1 gene was found located on plasmid types IncHI2, IncI2, and IncX4, as well as on the rarely described plasmid types IncFIB-FIC and IncFIB(K), phage-like plasmid p0111, and on the chromosome of E. coli. One E. coli strain carried the mcr-3.5 gene on IncFII(pCoo) plasmid in addition to the mcr-1.1 gene located on IncHI2 plasmid. K. pneumoniae was found to carry the mcr-1.1 and mcr-8.2 genes on IncFIA(HI1) plasmid. The mcr-4.3 gene was found on similar untypeable plasmids of A. baumannii and A. nosocomialis strains, pointing to the possible interspecies transfer of plasmids carrying the mcr-4 gene. Our results highlight that some aquaculture products of Asian origin can represent an important source of variable plasmids carrying mcr genes. The results showed an involvement of phages in the incorporation of the mcr-1 gene into plasmids or the chromosome in E. coli strains from aquaculture. The detection of E. coli with the mcr-1 gene in the chromosome points to the risks associated with the stabilisation of the mcr genes in the bacterial chromosome.
- Publikační typ
- časopisecké články MeSH
Background: In order to estimate the prevalence of plasmid borne colistin resistance and to characterize in detail the mcr-positive isolates, we carried out a sentinel testing survey on the intestinal carriage of plasmid-mediated colistin-resistant Enterobacteriaceae in hospitalized patients. Methods: Between June 2018 and September 2019, 1922 faecal samples from hospitalised patients were analysed by selective culture in presence of colistin (3.5 mg/L), and in parallel by direct detection of the mcr-1 to mcr-8 genes by qPCR. The mcr-positive isolates were characterised by whole-genome sequencing. Results: The prevalence of the mcr-1 gene was 0.21% (n = 4/1922); the mcr-2 to 8 genes were not detected. The mcr-1 gene was found to be localised in the IncX4 (n = 3) and IncHI2 (n = 1) plasmid type. One Escherichia coli isolate was susceptible to colistin due to the inactivation of the mcr-1 gene through the insertion of the IS2 element; however, the colistin resistance was inducible by culture in low concentrations of colistin. One human mcr-1 positive E. coli isolate was related genetically to the mcr-1 E. coli isolate derived from turkey meat of Czech origin. Conclusions:mcr-mediated colistin resistance currently poses little threat to patients hospitalised in Czech healthcare settings. The presence of the mcr-1 gene in the human population has a possible link to domestically produced, retail meat.
- Publikační typ
- časopisecké články MeSH
The great plasticity and diversity of the Escherichia coli genome, together with the ubiquitous occurrence, make E. coli a bacterium of world-wide concern. Of particular interest are pathogenic strains and strains harboring antimicrobial resistance genes. Overlapping virulence-associated traits between avian-source E. coli and human extraintestinal pathogenic E. coli (ExPEC) suggest zoonotic potential and safety threat of poultry food products. We analyzed whole-genome sequencing (WGS) data of 46 mcr-1-positive E. coli strains isolated from retail raw meat purchased in the Czech Republic. The investigated strains were characterized by their phylogroup-B1 (43%), A (30%), D (11%), E (7%), F (4%), B2 (2%), C (2%), MLST type, and serotype. A total of 30 multilocus sequence types (STs), of which ST744 was the most common (11%), were identified, with O8 and O89 as the most prevalent serogroups. Using the VirulenceFinder tool, 3 to 26 virulence genes were detected in the examined strains and a total of 7 (15%) strains met the pathogenic criteria for ExPEC. Four strains were defined as UPEC (9%) and 18 (39%) E. coli strains could be classified as APEC. The WGS methods and available on-line tools for their evaluation enable a comprehensive approach to the diagnosis of virulent properties of E. coli strains and represent a suitable and comfortable platform for their detection. Our results show that poultry meat may serve as an important reservoir of strains carrying both virulence and antibiotic resistance genes for animal and human populations.
- Publikační typ
- časopisecké články MeSH
- MeSH
- Campylobacter růst a vývoj MeSH
- kampylobakterové infekce * přenos prevence a kontrola veterinární MeSH
- lidé MeSH
- nemoci přenášené potravou MeSH
- novorozenec MeSH
- otrava salmonelou přenos prevence a kontrola veterinární MeSH
- plazi mikrobiologie MeSH
- přenos infekční nemoci MeSH
- Salmonella růst a vývoj MeSH
- salmonelová infekce u zvířat přenos MeSH
- salmonelóza * přenos MeSH
- techniky typizace bakterií metody MeSH
- zvířata MeSH
- Check Tag
- lidé MeSH
- novorozenec MeSH
- zvířata MeSH
- Publikační typ
- kazuistiky MeSH
