Epidemic HI2 Plasmids Mobilising the Carbapenemase Gene blaIMP-4 in Australian Clinical Samples Identified in Multiple Sublineages of Escherichia coli ST216 Colonising Silver Gulls.

Hassan Tarabai,Ibrahim Bitar,Monika Dolejska,Ethan R. Wyrsch,Steven P. Djordjevic

doi:10.3390/microorganisms9030567

Abstract

Escherichia coli ST216, including those that carry blaKPC-2, blaFOX-5, blaCTX-M-15 and mcr-1, have been linked to wild and urban-adapted birds and the colonisation of hospital environments causing recalcitrant, carbapenem-resistant human infections. Here we sequenced 22 multiple-drug resistant ST216 isolates from Australian silver gull chicks sampled from Five Islands, of which 21 carried nine or more antibiotic resistance genes including blaIMP-4 (n = 21), blaTEM-1b (n = 21), aac(3)-IId (n = 20), mph(A) (n = 20), catB3 (n = 20), sul1 (n = 20), aph(3”)-Ib (n = 18) and aph(6)-Id (n = 18) on FIB(K) (n = 20), HI2-ST1 (n = 11) and HI2-ST3 (n = 10) plasmids. We show that (i) all HI2 plasmids harbour blaIMP-4 in resistance regions containing In809 flanked by IS26 (HI2-ST1) or IS15DI (HI2-ST3) and diverse metal resistance genes; (ii) HI2-ST1 plasmids are highly related to plasmids reported in diverse Enterobacteriaceae sourced from humans, companion animals and wildlife; (iii) HI2 were a feature of the Australian gull isolates and were not observed in international ST216 isolates. Phylogenetic analyses identified close relationships between ST216 from Australian gull and clinical isolates from overseas. E. coli ST216 from Australian gulls harbour HI2 plasmids encoding resistance to clinically important antibiotics and metals. Our studies underscore the importance of adopting a one health approach to AMR and pathogen surveillance.

Highlights

Bacterial isolates resistant to antimicrobials have been isolated from wildlife [1] and there are concerns that wild animals act as critically important vectors and reservoirs for antimicrobial resistant bacteria and antibiotic resistance genes (ARGs) [2,3]
We report the carriage of multidrug resistant (MDR) E. coli ST216 by silver gulls on Five Islands near Wollongong, Australia harbouring diverse plasmids that carry multiple ARGs, virulence-associated genes (VAGs) and metal resistance genes
ARGs within HI2 plasmids were assembled in complex resistance regions together with metal resistance genes and multiple copies of IS elements including IS26 and IS26 derivative IS15DI

Summary

Introduction

Bacterial isolates resistant to antimicrobials have been isolated from wildlife [1] and there are concerns that wild animals act as critically important vectors and reservoirs for antimicrobial resistant bacteria and antibiotic resistance genes (ARGs) [2,3]. Microorganisms 2021, 9, 567 to antibiotics, heavy metals and virulence genes often coassemble on the same plasmid, mediated in part by the activity of insertion elements such as IS26 [15,16,17,18]. These factors allow the emergence of lineages that carry complex resistance regions and virulence gene profiles [14,19]. Hybrid Escherichia coli carrying combinations of virulence genes from different pathovars are increasingly recognised as an emerging threat to human and animal health [22]

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Conclusion