P106

1:Irish Mycobacteria Reference Laboratory, St. James’s Hospital, Dublin, Ireland; 2:Department of Clinical Microbiology, Trinity College Dublin, the University of Dublin, Ireland; 3:Public Health Laboratory, Health Service Executive in Dublin, Cherry Orchard Hospital, Dublin, Ireland; 4:Division of Infectious Diseases and Hospital Epidemiology, University Hospital Basel, Basel, Switzerland; 5:Laboratory Medicine, University Hospital Basel, Basel, Switzerland; 6:Department of Clinical Bacteriology and Mycology, University Hospital Basel, Basel, Switzerland

Routine surveillance of heater cooler-units has been performed in Ireland since 2015 due to the risk of Mycobacterium chimaera cardiovascular infection associated with contaminated heater-cooler units (HCU) manufactured by LivaNova. This also led to the replacement of these devices with another HCU brand, Maquet (Getinge), in nine Irish cardiac surgery centres. Here we report the detection of Mycobacterium chelonae contamination in Maquet HCU and LivaNova HCU used in five centres over a nine-year period. Whole genome sequencing was performed on 41 M. chelonae isolates from various types of HCU brands, unrelated environmental sources and unrelated patients to investigate the source of contamination. We also included five M. chelonae isolates associated with Maquet HCU from the University Hospital of Basel in Switzerland. Phylogenetic analysis based on WGS showed that M. chelonae isolates from various HCU brands were identified in the same group. M. chelonae isolates from Maquet HCU in Ireland and Switzerland were closely related (median pairwise distance of 5 SNPs) and were unrelated to M. chelonae isolates from LivaNova HCU and other sources. In conclusion, WGS of M. chelonae isolates from Maquet HCU from Ireland and Switzerland suggests that there is a common source of contamination in Maquet HCU, potentially at the manufacturers site or with products commonly used with these HCU’s, which poses a potential risk of infection to patients undergoing cardiac surgery. Other NTM including Mycobacterium gordonae were also frequently identified in Maquet HCU’s and further work is required to investigate the origin of contamination.