Public transport represents a potential site for the transmission of resistant pathogens due to the rapid movement of large numbers of people. This study aimed to investigate the bacterial contamination of frequently touched surfaces in the public transport system operating in the proximity of the biggest Czech hospital during the coronavirus pandemic despite extensive cleaning and disinfection efforts. In June and September 2020, samples from the metro trains, ground transport and stationary objects were collected, enriched and cultured. The antimicrobial susceptibility was tested by broth microdilution. Staphylococcus aureus isolates exhibiting inconclusive results of vancomycin susceptibility testing were retested by broth macrodilution and subjected to whole genome sequencing. All S. aureus isolates were tested for vancomycin heteroresistance (hVISA). A total of 513/542 (94.6 %) samples were culture-positive with higher frequency in September (p = 0.004). S. aureus was the most frequent opportunistic bacterial pathogen found (3.7 %, 20/542) followed by Enterobacterales spp. (1.8 %, 10/542). No methicillin-resistant S. aureus (MRSA), extended-spectrum beta-lactamase producers (ESBL) or carbapenemase-producing bacteria were detected. Resistance to clinically relevant drugs was rare except for resistance to ampicillin (67 %, 8/12), cefuroxime (42 %, 5/12) in Enterobacterales and chloramphenicol (90 %, 18/20), penicillin (45 %, 9/20), and erythromycin (20 %, 4/20) in S. aureus. One S. aureus isolate was shown to be resistant to vancomycin (8 mg/L) by forming large visible cell aggregates. Population analysis profile-area under the curve ratio (PAP-AUC) testing did not confirm the hVISA phenotype, but mutations in the hVISA phenotype-related gene vraR and other genes related to cell wall synthesis (fmtB) and intercellular adhesion (sasC) were found. Our study shows that in the COVID-19 pandemic, despite the intensive use of disinfectants, public transport was a source of opportunistic bacterial pathogens including S. aureus with unusual vancomycin resistance phenotype that could be easily missed by standard susceptibility testing.
- MeSH
- antibakteriální látky * farmakologie MeSH
- COVID-19 * MeSH
- doprava MeSH
- lidé MeSH
- mikrobiální testy citlivosti * MeSH
- pandemie MeSH
- rezistence na vankomycin MeSH
- SARS-CoV-2 * MeSH
- Staphylococcus aureus * účinky léků genetika MeSH
- vankomycin * farmakologie MeSH
- Check Tag
- lidé MeSH
- Publikační typ
- časopisecké články MeSH
- Geografické názvy
- Česká republika MeSH
BACKGROUND: Colistin belongs to the last-resort antibiotics. The discovery of plasmid-bound colistin resistance mediated by the mcr-gene(s) is of great concern because, given its biological potential, there is a risk of its rapid spread. OBJECTIVES: To discuss the current literature on the methods for the screening for mcr-mediated resistance to colistin. SOURCES: Literature was drawn from a search of PubMed from 1 January 2016 to 26 April 2021. CONTENT: The selective culture-based or culture-independent approach can be used for the screening of mcr-mediated resistance to colistin in clinical samples. Rapid Polymyxin NP, Colistin Drop or Colistin Agar Spot tests are applicable for the selection of isolates with a suspected resistance to colistin that has to be confirmed by broth microdilution. The mcr-mediated resistance to colistin can be confirmed by the detection of the causal gene(s) or by phenotype using EDTA-colistin broth disc elution; production of the MCR-1 enzyme can be confirmed with lateral flow immunoassay, using matrix-assisted laser desorption/ionization time-of flight or liquid chromatography-based mass spectrometry. Whole-genome sequencing (WGS) is the ultimate typing method. When a WGS platform is not available at a healthcare facility, a WGS-outsourced service, in combination with freely available bioinformatics tools, allows for the characterization of the mcr-gene(s) carrying isolates. IMPLICATIONS: mcr-mediated colistin resistance should be monitored through active targeted screening. The broth microdilution method is required for colistin susceptibility testing but as only a selected number of clinical isolates are tested, colistin resistance, including mcr-mediated, may remain undetected. In mcr-1-positive Escherichia coli isolates, the MIC to colistin can range from 2 to 8 mg/L, so it is proposed that Enterobacterales with a colistin MIC of 2 mg/L should also be included in the mcr-mediated colistin resistance screening and those with a confirmed mcr-genotype and/or MCR-phenotype should be considered to be colistin-resistant.
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
Úvod: Kolistin je rezervním antibiotikem používaným pro léčbu infekcí, způsobených multirezistentními gramnegativními patogeny. Plazmidově vázaná kolistinová rezistence mediovaná geny mcr představuje zvýšené riziko šíření a její výskyt by měl být monitorován. Cílem této práce je diskutovat možné metody detekce a jejich spolehlivost pro vyhledávání tohoto typu rezistence. Materiál a metody: Spolehlivost diskové difuzní metody, Rapid Polymyxin NP testu a dvou typů gradientových testů pro vyhledávání rezistence ke kolistinu mediované geny mcr byla evaluována na 16 humánních a dvou referenčních kmenech Escherichia coli (ke kolistinu citlivé a rezistentní s chromozomální mutací nebo nesoucí gen mcr-1). Referenční metodou pro stanovení rezistence ke kolistinu byla mikrodiluční metoda. Výsledky: Pro cílené vyhledávání kmenů rezistentních ke kolistinu je vhodné použít selektivní médium s přídavkem kolistinu. U získaných izolátů je nutné vždy suspektní kolistinovou rezistenci konfirmovat spolehlivou metodou. Porovnávané gradientové metody i Rapid Polymyxin NP test vykazovaly 100% shodu s referenční mikrodiluční metodou. Při použití diskové difuzní metody byl jednoznačně a správně vyhodnocen výsledek pouze v 11 % a 33 % případů při použití 10μg a 50μg disku. Jedná se tedy o metodu nevhodnou pro vyhledávání kolistinové rezistence. Závěr: Prospektivní prevalenční studie střevního nosičství u hospitalizovaných pacientů a cestovatelů v České republice prozatím nenaznačují rozšíření kmenů s plazmidově kódovanou rezistencí ke kolistinu mediovanou geny mcr. Nicméně vysoká prevalence kmenů nesoucích geny mcr ve výrobcích ze syrového masa představuje riziko expozice pro jejich konzumenty. Při rutinním mikrobiologickém vyšetření nelze předpokládat, že ke kolistinu rezistentní kmeny nesoucí geny mcr budou odhaleny bez cíleného vyhledávání s použitím spolehlivých, ale nákladných metod. Vhodnou alternativní metodou pro aktivní vyhledávání rezistence ke kolistinu je selektivní kultivace na půdách s kolistinem s ověřením rezistence u zachycených izolátů.
Background: Colistin is a last-resort antibiotic used for the treatment of infections caused by multidrug-resistant Gram-negative pathogens. The emergence of plasmid-borne colistin resistance mediated by the mcr genes poses a risk of its spread and its occurrence should be monitored. The aim of this study was to discuss possible detection methods and their reliability in screening for this type of resistance. Material and methods: The reliability of the disk diffusion method, Rapid Polymyxin NP test and two types of gradient tests for the screening of mcr-mediated colistin resistance was evaluated on 16 human and two reference isolates of Escherichia coli (colistin-susceptible and colistin-resistant with chromosomally-mediated resistance or harboring the mcr-1 gene). Broth microdilution was the reference method used for the determination of colistin resistance. Results: Targeted screening for colistin-resistant strains is best performed with a selective agar medium supplemented with colistin. In cultured isolates, suspected colistin resistance should always be confirmed by reliable methods. There was 100 percent agreement between both the gradient methods and the Rapid Polymyxin NP test and the reference broth microdilution method. When using the disk diffusion method with 10μg and 50μg disks, only 11 % and 33 % of results were correct, respectively. Therefore, disk diffusion is inappropriate for colistin resistance screening. Conclusion: Prospective prevalence studies of intestinal carriage of colistin-resistant Enterobacterales among Czech hospitalized patients and travelers do not yet indicate the spread of strains with mcr-mediated plasmid-borne colistin resistance. However, the high prevalence of strains carrying the mcr genes in raw meat products poses a risk of exposure for their consumers. The detection of mcr- harbouring colistin-resistant strains cannot be expected during routine microbiological testing, without using reliable but expensive methods. A suitable alternative method for active monitoring of colistin resistance is the use of selective agar media with colistin followed by verification of the resistance in the obtained isolates.
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
OBJECTIVES: To gain data on the current molecular epidemiology and resistance of MRSA in the Czech Republic. METHODS: Between September 2017 and January 2018, a total of 441 single-patient MRSA isolates were collected from 11 Czech hospitals and analysed by spa typing, SCCmec typing, antibiotic susceptibility testing, detection of the PVL toxin and the arcA gene. RESULTS: Of all MRSA isolates, 81.41% (n = 359) belonged to the CC5-MRSA clone represented by the spa types t003 (n = 136), t586 (n = 92), t014 (n = 81), t002 (n = 20) and other spa types (n = 30); a majority of the CC5 isolates (n = 348, 96.94%) carried SCCmec type II. The occurrence of CC5-MRSA was more likely in older inpatients and associated with a healthcare origin (P < 0.001). The CC5-MRSA isolates were resistant to more antimicrobial drugs compared with the other MRSAs (P < 0.001). Interestingly, t586 was detected in blood samples more often than the other spa types and, contrary to other spa types belonging to CC5-MRSA, t586 was not associated with patients of advanced age. Other frequently found lineages were CC8 (n = 17), CC398 (n = 11) and CC59 (n = 10). The presence of the PVL was detected in 8.62% (n = 38) of the MRSA isolates. CONCLUSIONS: The healthcare-associated CC5-MRSA-II lineage (t003, t586, t014) was found to be predominant in the Czech Republic. t586 is a newly emerging spa type in the Czech Republic, yet reported rarely in other countries. Our observations stress the need for MRSA surveillance in the Czech Republic in order to monitor changes in MRSA epidemiology.
- MeSH
- antibakteriální látky farmakologie MeSH
- genotyp MeSH
- lidé MeSH
- methicilin rezistentní Staphylococcus aureus * genetika MeSH
- mikrobiální testy citlivosti MeSH
- molekulární epidemiologie MeSH
- senioři MeSH
- stafylokokové infekce * epidemiologie MeSH
- Check Tag
- lidé MeSH
- senioři MeSH
- Publikační typ
- časopisecké články MeSH
- práce podpořená grantem MeSH
- Geografické názvy
- Česká republika MeSH
- MeSH
- antibakteriální látky škodlivé účinky MeSH
- Bacteria růst a vývoj účinky léků MeSH
- bakteriální léková rezistence * účinky léků MeSH
- biofilmy účinky léků MeSH
- guanosinpentafosfát MeSH
- lidé MeSH
- quorum sensing účinky léků MeSH
- SOS odpověď (genetika) účinky léků MeSH
- systémy toxin-antitoxin účinky léků MeSH
- Check Tag
- lidé MeSH
- Publikační typ
- práce podpořená grantem MeSH
- přehledy MeSH
