Carbapenem and colistin resistance in Enterobacteriaceae in Southeast Asia: Review and mapping of emerging and overlapping challenges

•Data from 258 studies on carbapenem and polymyxin resistance in Southeast Asia were analysed.•Carbapenem-resistant E. coli and Klebsiella were reported in 8 and 9 of 11 nations, respectively.•Resistance was significant, especially in Klebsiella, with NDM and OXA as common carbapenemases.•Polymyxin resistance was also widespread, with mcr-1 the predominant genotype.•Widespread resistance to both antimicrobial classes, overlapping in 8 nations, is a major public-health threat. Carbapenem-resistant Enterobacteriaceae infections have spread globally, leaving polymyxins, including colistin, as ‘last-resort treatments’. Emerging colistin resistance raises the spectre of untreatable infections. Despite this threat, data remain limited for much of the world, including Southeast Asia where only 3 of 11 nations submitted data on carbapenem and colistin resistance for recent World Health Organization (WHO) reports. To improve our understanding of the challenge, we utilised broad strategies to search for and analyse data on carbapenem and colistin resistance among Escherichia coli and Klebsiella in Southeast Asia. We found 258 studies containing 526 unique reports and document carbapenem-resistant E. coli and Klebsiella in 8 and 9 of 11 nations, respectively. We estimated carbapenem resistance proportions through meta-analysis of extracted data for nations with ≥100 representative isolates. Estimated resistance among Klebsiella was high (>5%) in four nations (Indonesia, Philippines, Thailand and Vietnam), moderate (1–5%) in two nations (Malaysia and Singapore) and low (