RT Journal Article
SR Electronic
T1 <em>cfrB, cfrC</em>, and a potential new <em>cfr</em>-like gene in <em>Clostridium difficile</em> strains recovered across Latin America
JF bioRxiv
FD Cold Spring Harbor Laboratory
SP 649020
DO 10.1101/649020
A1 Vanja Stojković
A1 María Fernanda Ulate
A1 Fanny Hidalgo-Villeda
A1 Emmanuel Aguilar
A1 Camilo Monge-Cascante
A1 Marjorie Pizarro-Guajardo
A1 Kaitlyn Tsai
A1 Edgardo Tzoc
A1 Margarita Camorlinga
A1 Daniel Paredes-Sabja
A1 Carlos Quesada-Gómez
A1 Danica Galonić Fujimori
A1 César Rodríguez
YR 2019
UL http://biorxiv.org/content/early/2019/05/24/649020.abstract
AB Cfr is a radical S-adenosyl-L-methionine (SAM) enzyme that confers cross-resistance to all antibiotics targeting the large ribosomal subunit through hypermethylation of nucleotide A2503 of 23S rRNA. Of the four known cfr genes known to date, cfr(B) and cfr(C) have been sporadically found in C. difficile, yet functional characterization of cfr(C) is still lacking. We identified genes for putative Cfr-like enzymes among clinical C. difficile strains from Mexico, Honduras, Costa Rica, and Chile. To confirm their identity and activity, we obtained minimum inhibitory concentrations for ribosome-targeting antibiotics, annotated whole genome sequences, and performed a functional characterization of Cfr(C). The seven representative isolates analyzed displayed different levels of resistance to PhLOPSA antibiotics in the absence of the ribosome protection factor OptrA, and mutations in genes for 23S rRNAs or the ribosomal proteins L3 and L4. cfr(B) was detected in four isolates as part of a Tn6218-like transposon or an un-described mobile genetic element. In turn, cfr(C) was found integrated into an ICE-element. One isolate harbored a putative cfr-like gene that shows only 51-58% of sequence identity to Cfr and known Cfr-like enzymes. Moreover, our in vitro assays confirmed that Cfr(C) methylates E. coli and C. difficile 23S rRNA fragments. These results indicate selection of cfr-like genes in C. difficile from Latin America, suggest that the diversity of cfr-like resistance genes is larger than anticipated, and provide the first assessment of the methylation activity of Cfr(C).