Containing a PER-1-producing Pseudomonas aeruginosa outbreak linked to sink contamination in an intensive care unit

Background: (PaePER) was detected in the ICU of a university hospital in Uruguay. Aim: The objective was to describe the clinical epidemiology, confirm the environmental source and assess the impact of control measures. Methods: was confirmed by polymerase chain reaction. Clonal relatedness was assessed by pulsed-field gel electrophoresis (PFGE). Control measures included discontinuation of patient room sink use, relocation of medication preparation, renewal of drainage systems and scheduled decontamination with a solution of 15% acetic acid. Findings: Among 1221 exposed patients, 31 were affected (attack rate: 2.8%): 25 infections and six colonisation episodes. Eighty-three clinical isolates were recovered, mainly from respiratory and blood samples. Isolates showed high resistance to ceftazidime, cefepime, ceftazidime/avibactam, ceftolozane/tazobactam and amikacin, with preserved susceptibility to carbapenems and cefiderocol. PaePER was recovered from four of seven sinks. PFGE confirmed a single ST309 clone. Conclusion: Sinks and drainage systems acted as the source of a PaePER outbreak. Targeted interventions rapidly interrupted transmission.