OBJECTIVES: To analyse characteristics of Clostridioides difficile PCR ribotype 176 clinical isolates from Poland, the Czech Republic and Slovakia with regard to the differences in its epidemiology. METHODS: Antimicrobial susceptibility testing and whole genome sequencing were performed on a selected group of 22 clonally related isolates as determined by multilocus variable-number tandem repeat analysis (n = 509). Heterologous expression and functional analysis of the newly identified methyltransferase were performed. RESULTS: Core genome multilocus sequence typing found 10-37 allele differences. All isolates were resistant to fluoroquinolones (gyrA_p. T82I), aminoglycosides with aac(6')-Ie-aph(2'')-Ia in six isolates. Erythromycin resistance was detected in 21/22 isolates and 15 were also resistant to clindamycin with ermB gene. Fourteen isolates were resistant to rifampicin with rpoB_p. R505K or p. R505K/H502N, and five to imipenem with pbp1_p. P491L and pbp3_p. N537K. PnimBG together with nimB_p. L155I were detected in all isolates but only five were resistant to metronidazole on chocolate agar. The cfrE, vanZ1 and cat-like genes were not associated with linezolid, teicoplanin and chloramphenicol resistance, respectively. The genome comparison identified six transposons carrying antimicrobial resistance genes. The ermB gene was carried by new Tn7808, Tn6189 and Tn6218-like. The aac(6')-Ie-aph(2'')-Ia were carried by Tn6218-like and new Tn7806 together with cfrE gene. New Tn7807 carried a cat-like gene. Tn6110 and new Tn7806 contained an RlmN-type 23S rRNA methyltransferase, designated MrmA, associated with high-level macrolide resistance in isolates without ermB gene. CONCLUSIONS: Multidrug-resistant C. difficile PCR ribotype 176 isolates carry already described and unique transposons. A novel mechanism for erythromycin resistance in C. difficile was identified.

• Klíčová slova
• Clostridioides difficile infection, epidemiology, macrolide resistance methyltransferase, whole genome sequencing,
• MeSH
• antibakteriální látky * farmakologie   MeSH
• bakteriální léková rezistence * MeSH
• bakteriální proteiny genetika   MeSH
• Clostridioides difficile * genetika   účinky léků   izolace a purifikace   klasifikace   MeSH
• genomové ostrovy * MeSH
• klostridiové infekce * mikrobiologie   epidemiologie   MeSH
• lidé MeSH
• methyltransferasy genetika   MeSH
• mikrobiální testy citlivosti MeSH
• mnohočetná bakteriální léková rezistence * genetika   MeSH
• multilokusová sekvenční typizace MeSH
• ribotypizace MeSH
• sekvenování celého genomu MeSH
• Check Tag
• lidé MeSH
• Publikační typ
• časopisecké články MeSH
• Geografické názvy
• Česká republika epidemiologie   MeSH
• Polsko epidemiologie   MeSH
• Názvy látek
• antibakteriální látky * MeSH
• bakteriální proteiny MeSH
• methyltransferasy MeSH

The use of whole-genome phylogenetic analysis has revolutionized our understanding of the evolution and spread of many important bacterial pathogens due to the high resolution view it provides. However, the majority of such analyses do not consider the potential role of accessory genes when inferring evolutionary trajectories. Moreover, the recently discovered importance of the switching of gene regulatory elements suggests that an exhaustive analysis, combining information from core and accessory genes with regulatory elements could provide unparalleled detail of the evolution of a bacterial population. Here we demonstrate this principle by applying it to a worldwide multi-host sample of the important pathogenic E. coli lineage ST131. Our approach reveals the existence of multiple circulating subtypes of the major drug-resistant clade of ST131 and provides the first ever population level evidence of core genome substitutions in gene regulatory regions associated with the acquisition and maintenance of different accessory genome elements.

• MeSH
• antibiotická rezistence genetika   MeSH
• Escherichia coli genetika   patogenita   MeSH
• fylogeneze MeSH
• genom bakteriální účinky léků   MeSH
• infekce vyvolané Escherichia coli farmakoterapie   genetika   MeSH
• lidé MeSH
• molekulární evoluce * MeSH
• regulační oblasti nukleových kyselin genetika   MeSH
• sekvenční analýza DNA MeSH
• Check Tag
• lidé MeSH
• Publikační typ
• časopisecké články MeSH