Genomic islands and molecular mechanisms relating to drug-resistance in Clostridioides (Clostridium) difficile PCR ribotype 176
Series / Report no.
Open Access
Type
Journal Article
Article
Article
Language
en
Date
2025-04-09
Research Projects
Organizational Units
Journal Issue
Title
Genomic islands and molecular mechanisms relating to drug-resistance in Clostridioides (Clostridium) difficile PCR ribotype 176
Translated Title
Published in
Emerg Microbes Infect 2025; 14(1):2482698
Abstract
To analyse characteristics of PCR ribotype 176 clinical isolates from Poland, the Czech Republic and Slovakia with regard to the differences in its epidemiology.
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.
Core genome multilocus sequence typing found 10-37 allele differences. All isolates were resistant to fluoroquinolones (A_p. T82I), aminoglycosides with (6')-(2'')- in six isolates. Erythromycin resistance was detected in 21/22 isolates and 15 were also resistant to clindamycin with B gene. Fourteen isolates were resistant to rifampicin with B_p. R505K or p. R505K/H502N, and five to imipenem with 1_p. P491L and 3_p. N537K. PB together with B_p. L155I were detected in all isolates but only five were resistant to metronidazole on chocolate agar. The E, Z1 and -like genes were not associated with linezolid, teicoplanin and chloramphenicol resistance, respectively. The genome comparison identified six transposons carrying antimicrobial resistance genes. The B gene was carried by new Tn, Tn and Tn-like. The (6')-(2'')- were carried by Tn-like and new Tn together with E gene. New Tn carried a -like gene. Tn and new Tn contained an RlmN-type 23S rRNA methyltransferase, designated MrmA, associated with high-level macrolide resistance in isolates without B gene.
Multidrug-resistant PCR ribotype 176 isolates carry already described and unique transposons. A novel mechanism for erythromycin resistance in was identified.
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.
Core genome multilocus sequence typing found 10-37 allele differences. All isolates were resistant to fluoroquinolones (A_p. T82I), aminoglycosides with (6')-(2'')- in six isolates. Erythromycin resistance was detected in 21/22 isolates and 15 were also resistant to clindamycin with B gene. Fourteen isolates were resistant to rifampicin with B_p. R505K or p. R505K/H502N, and five to imipenem with 1_p. P491L and 3_p. N537K. PB together with B_p. L155I were detected in all isolates but only five were resistant to metronidazole on chocolate agar. The E, Z1 and -like genes were not associated with linezolid, teicoplanin and chloramphenicol resistance, respectively. The genome comparison identified six transposons carrying antimicrobial resistance genes. The B gene was carried by new Tn, Tn and Tn-like. The (6')-(2'')- were carried by Tn-like and new Tn together with E gene. New Tn carried a -like gene. Tn and new Tn contained an RlmN-type 23S rRNA methyltransferase, designated MrmA, associated with high-level macrolide resistance in isolates without B gene.
Multidrug-resistant PCR ribotype 176 isolates carry already described and unique transposons. A novel mechanism for erythromycin resistance in was identified.