Global epidemiology of CTX-M β-lactamases: temporal and geographical shifts in genotype

Abstract

Globally, rates of ESBL-producing Enterobacteriaceae are rising. We undertook a literature review, and present the temporal trends in blaCTX-M epidemiology, showing that blaCTX-M-15 and blaCTX-M-14 have displaced other genotypes in many parts of the world. Explanations for these changes can be attributed to: (i) horizontal gene transfer (HGT) of plasmids; (ii) successful Escherichia coli clones; (iii) ESBLs in food animals; (iv) the natural environment; and (v) human migration and access to basic sanitation. We also provide explanations for the changing epidemiology of blaCTX-M-2 and blaCTX-M-27. Modifiable anthropogenic factors, such as poor access to basic sanitary facilities, encourage the spread of blaCTX-M and other antimicrobial resistance (AMR) genes, such as blaNDM, blaKPC and mcr-1. We provide further justification for novel preventative and interventional strategies to reduce transmission of these AMR genes.

Reduced antibacterial drug resistance and blaCTX-M β-lactamase gene carriage in cattle-associated Escherichia coli at low temperatures, at sites dominated by older animals and on pastureland: implications for surveillance

“…3GC-resistance is increasingly common in E. coli causing infections in humans (6) and is also found in farmed and domestic animals around the world (7). The production of CTX-M (an extended-spectrum β-lactamase) is the most common mechanism of 3GC-resistance in E. coli in humans in the UK; for example, in a recent study of urinary E. coli from humans in South West England, 82.2% of 3GC-resistant isolates carried bla CTX-M (8).…”

Molecular epidemiology of Escherichia coli producing CTX-M and plasmid AmpC-type β-lactamases from dairy farms identifies a dominant plasmid encoding CTX-M-32 but no evidence for transmission to humans in the same geographical region

“…Third generation cephalosporin (3GC)-resistant Escherichia coli have been increasingly reported in both animal and human populations, and are considered pathogens of major concern for humans. 1, 2 3GCs, such as cefotaxime and ceftazidime, have been listed by the World Health Organisation (WHO) as “highest-priority critically important antimicrobials” (HP-CIAs) because of their importance for human health. 3 Resistance to 3GCs in E. coli can be caused by a number of mechanisms but is primarily attributed to the acquisition of ESBLs and/or plasmid-mediated AmpCs (pAmpCs).…”

“…bla CTX-M -encoding ST131) play a major role in the dissemination of ESBL genes, however such a depth of information does not exist for isolates from animal populations. 2 Human-associated pandemic lineages have been reported in animal populations albeit to a much lesser extent than in human populations. 7…”

“…bla CTX-M-15 in Europe and North America and bla CTX-M-14 in Asia). 2 Transmission of ESBLs is largely as a result of horizontal gene transfer, with conjugative IncF plasmids in particular being reported as the dominant vehicles for bla CTX-M genes. 8, 9 Previous studies using typing methodologies including WGS have suggested transmission of both strains and ESBL plasmids across animal and human populations.…”

Low prevalence of zoonotic multidrug‐resistant bacteria in veterinarians in a country with prudent use of antimicrobials in animals

“…Three veterinarians carried ESBL E. coli belonging to ST131 and harbouring bla CTX‐M‐15 , bla CTX‐M‐14 or bla CTX‐M‐27 . The most prevalent ESBL genes in humans globally are bla CTX‐M‐15 and bla CTX‐M‐14 , but the importance of bla CTX‐M‐27 is growing (Bevan, Jones, & Hawkey, ). These genes are often associated with ST131.…”