First reported detection of the mobile colistin resistance genes,mcr-8 andmcr-9, in the Irish environment

• DOI: 10.1101/2022.11.03.515100
• Publication Date: 2022-11-05T02:36:36Z
• Authors: Niamh Cahill; Brigid Hooban; Kelly Fitzhenry; Aoife Joyce; Louise O’Connor; Georgios Miliotis; Francesca McDonagh; Liam Burke; Alexandra Chueiri; Maeve Louise Farrell; James E. Bray; Niall Delappe; Wendy Brennan; Deirdre Prendergast; Montserrat Gutierrez; Catherine Burgess; Martin Cormican; Dearbháile Morris
• Keywords: Colistin; MCR-1

Abstract The emergence and dissemination of mobile colistin resistance ( mcr ) genes across the globe poses a significant threat to public health, as remains one last line treatment options for multi-drug resistant infections. Environmental samples (157 water 157 wastewater) were collected in Ireland between 2018 2020. Samples assessed presence antimicrobial bacteria using Brilliance ESBL, CRE, mSuperCARBA McConkey agar containing ciprofloxacin disc. All integrated constructed wetland influent effluent filtered enriched buffered peptone prior culture, while wastewater cultured directly. Isolates identified via MALDI-TOF, tested susceptibility 16 antimicrobials, including colistin, subsequently underwent whole genome sequencing. Overall, eight positive Enterobacterales (one -8 seven -9) recovered from six (freshwater (n=2), healthcare facility plant (n=1) (piggery farm waste) (n=1)). While K. pneumoniae displayed all -9 harbouring remained susceptible. isolates demonstrated through sequencing analysis, found harbour wide variety i.e., 30 ± 4.1 (10-61), carbapenemases, bla OXA-48 (n=2) NDM-1 (n=1), which harboured by three isolates. located on IncHI2, IncFIIK IncI1-like plasmids. findings this study highlight potential sources reservoirs environment illustrate need further research gain better understanding role plays persistence resistance.