Klebsiella pneumoniae sequence type 11 from companion animals bearing ArmA methyltransferase, DHA-1 β-lactamase, and QnrB4

Seven Klebsiella pneumoniae isolates from dogs and cats in Spain were found to be highly resistant to aminoglycosides, and ArmA methyltransferase was responsible for this phenotype. All isolates were typed by multilocus sequence typing (MLST) as ST11, a human epidemic clone reported worldwide and associated with, among others, OXA-48 and NDM carbapenemases. In the seven strains, armA was borne by an IncR plasmid, pB1025, of 50 kb. The isolates were found to coproduce DHA-1 and SHV-11 β-lactamases, as well as the QnrB4 resistance determinant. This first report of the ArmA methyltransferase in pets illustrates their importance as a reservoir for human multidrug-resistant K. pneumoniae.

Association of extended-spectrum β-lactamase VEB-5 and 16S rRNA methyltransferase armA in Salmonella enterica from the United Kingdom

Aminoglycosides and beta-lactams are used for the treatment of a wide range of infections due to both Gram-negative and Gram-positive. An emerging aminoglycoside resistance mechanism, methylation of the aminoacyl site of the 16S rRNA, confers high-level resistance to clinically important aminoglycosides such as amikacin, tobramycin and gentamicin. Eight 16S rRNA methyltransferase genes, armA, rmtA, rmtB, rmtC, rmtD, rmtE, rmtF and npmA, have been identified in several species of enterobacteria worldwide (2, 6, 7, 9, 11, 13, 14). Resistance to extended spectrum β-lactams remains additionally an important clinical problem. Apart from the large TEM, SHV, and CTX-M families, several other extended-spectrum β-lactamases (ESBLs) have been identified, including VEB enzymes, which confer high-level resistance to cephalosporins and monobactams. Although 16S rRNA methyltransferases have been frequently identified associated with different ESBLs, there has been no report of association of a 16S rRNA methyltransferase with a VEB enzyme, except for the identification of rmtC with blaVEB-6 (14)