Cryptic transmission of ST405 Escherichia coli carrying bla NDM-4 in hospital

Abstract

Three carbapenem-resistant Escherichia coli were recovered from rectal swabs of different patients in a tertiary hospital and were found carrying bla NDM-4, an uncommon bla NDM variant. Genome sequences of the isolates were obtained using Illumina technology and the long-read MinION sequencer. The isolates belonged to ST405 and phylogenetic group D, a globally distributed lineage associated with antimicrobial resistance. In addition to bla NDM-4, the three isolates carried 14 known resistance genes including the extended-spectrum β-lactamase gene bla CTX-M-15. There were only 1 or 2 SNPs between the isolates, suggesting a common origin and cryptic transmission in hospital. bla NDM-4 was located on a 46.5-kb IncFIA self-transmissible plasmid, which may facilitate further dissemination of bla NDM-4. Two copies of IS26 bracketed a 14.6-kb region containing bla NDM-4 and have the potential to form a composite transposon for mediating the mobilization of bla NDM-4.

First Indian report on genome-wide comparison of multidrug-resistant Escherichia coli from blood stream infections

“…ST167 was previously reported for its ability to carry bla NDM genes in China [38][39][40]. ST405 has been known as another global clonal group similar to ST131 [41] and has been reported to carry bla NDM genes in hospital settings [42], in addition to blaKPC-2 [43]. ST405 was reported as a lineage, carrying fluoroquinolone resistance in Japan [41].…”

Real-time sampling of travelers shows intestinal colonization by multidrug-resistant bacteria to be a dynamic process with multiple transient acquisitions

“…Whilst direct transmission cannot be confirmed, the clonality of the isolates suggests that the two colonization events did not result from exposure to a common environmental reservoir. Such reservoirs are generally colonized by bacteria for extended periods of time, which leads to extensive diversity within the bacterial population [25,26].…”

NDM Metallo-β-Lactamases and Their Bacterial Producers in Health Care Settings

“…Genetic contexts similar to those of bla NDM-1 are shared in other bla NDM variants, which are commonly associated with ISAba125 (intact or truncated) upstream and ble MBL downstream (29,95,123,(131)(132)(133)(134)(135). This suggests that other bla NDM variants emerged from bla NDM-1 via nucleotide mutations.…”