Expansion of acquired 16S rRNA methytransferases along with CTX-M-15, NDM and OXA-48 within three sequence types of Escherichia coli from northeast India

Abstract

Background This study aimed to identify ten different 16S rRNA methyltransferase genes ( rmtA, rmtB, rmtC, rmtD, armA, rmtF, npmA, rmtH, rmtE and rmtG) and their coexisting ESBL and carbapenemase with the emergence of three E.coli clones within a single study centre. Methods A total of 329 non-duplicate E.coli isolates were studied to detect the presence of 16S rRNA methyltransferases along with β-lactamases (TEM, SHV, OXA, VEB, GES, PER,CTX-M types, NDM, OXA-48,VIM, IMP and KPC) using PCR assay. Horizontal transferability were validated by transformation and conjugation analysis. Plasmid incompatibility typing and MLST analysis was also performed. Results A total of 117 isolates were found to be resistant to at least one of the aminoglycoside antibiotics. It was observed that 77 (65.8%) were positive for 16S rRNA methyltransferases. Among them thirty nine isolates were found to harbour only bla CTX-M-15 , whereas combination of genes were observed in three isolates ( bla VEB + bla CTX-M-15 in 2 isolates and bla PER + bla CTX-M-15 in 1 isolate). bla NDM and bla OXA-48 like genes were found in 23 and 9 isolates, respectively. All the resistance genes were conjugatively transferable, and incompatibility typing showed multiple 16S rRNA methyltransferase genes were originated from a single Inc. I1 group. MLST analysis detected 3 clones of E.coli ST4410, ST1341 and ST3906. Conclusion The present study identified emergence of three clones of E.coli , resistant to aminoglycoside -cephalosporin- carbapenem. This warrants immediate measures to trace their transmission dynamics in order to slow down their spread in clinical setting.

Co-Occurrence of Rare ArmA-, RmtB-, and KPC-2–Encoding Multidrug-Resistant Plasmids and Hypervirulence iuc Operon in ST11-KL47 Klebsiella pneumoniae

“…p1632-2 was another resistance plasmid harboring the armA gene. armA is a common element that conferred the high-level aminoglycoside phenotype that can be observed in the chromosome or multiple plasmids, belonging to different incompatibility groups (IncM2, IncFII, IncR, IncX1, and IncN) ( 20 – 24 ). In this study, the p1632-2 plasmid was typed as IncM2 plasmid and had an extremely high-conjugative frequency, higher than the other IncM2- armA plasmid pMS3802OXARMA studied before (10 −1 versus 10 −4 ) ( 25 ).…”

Global scenario of the RmtE pan-aminoglycoside-resistance mechanism: emergence of the rmtE4 gene in South America associated with a hospital-related IncL plasmid

“…proteins such as NDM-1 and CTX-M-15 [15][16][17]. The RmtE2 variant, with a single amino acid modification compared with RmtE1, was only described in two E. coli isolates from two diseased pigs in China in 2015, encoded in an IncI1 plasmid [18].…”

Research Updates of Plasmid-Mediated Aminoglycoside Resistance 16S rRNA Methyltransferase

“…At present, the rmtG gene was still mainly prevalent in South America, especially in K. pneumoniae isolated from Brazil. It also could be found in K. aerogenes, P. aeruginosa, and E. coli isolated in America, India, Switzerland [ 3 , 59 , 96 , 97 , 98 , 100 , 101 ]. However, no strain carrying rmtG has been found in China so far.…”

“…The mechanism of aminoglycosides is to bind the A site of 16S rRNA, which consists of the 30S ribosomal subunit, leading to the inhibition of protein synthesis and bacteria death [ 2 ]. Therefore, aminoglycosides have a broad spectrum of antimicrobial activity against both Gram-positive and Gram-negative bacteria and are often used in combination with β-lactam antibiotics, especially the third-generation cephalosporins [ 3 ].…”