The outbreak of multispecies carbapenemase-producing Enterobacterales associated with pediatric ward sinks: IncM1 plasmids act as vehicles for cross-species transmission
Mayumi Tsukada, Taito Miyazaki, Kotaro Aoki, Sadako Yoshizawa, Yoko Kondo, Tomoka Sawa, Hinako Murakami, Emi Sato, Manabu Tomida, Mariko Otani, Eri Kumade, Emi Takamori, Masako Kambe, Yoshikazu Ishii, Kazuhiro Tateda
Abstract
•An outbreak due to CPE of multiple species was observed in a pediatric ward.•An environmental survey suggested that the pediatric-ward sink may have been a factor in the transmission.•Draft whole-genome sequencing (dWGS) analysis revealed IncM1 plasmids act as vehicles for cross-species transmission.•CPE was still detected after sink replacement, and the outbreak was terminated by strengthening sink-related infection-control measures as a bundle. BackgroundThis study describes an outbreak caused by multispecies carbapenemase-producing Enterobacterales (CPE) occurring in a pediatric ward at an academic medical center in Tokyo.MethodsThe index case involved a 1-year-old boy with Klebsiella variicola (CPE) detected in anal swabs in June 2016. The second case was Klebsiella quasipneumoniae (CPE) occurred in March 2017 followed by further spread, leading to the declaration of an outbreak in April 2017. Extensive environmental and patient microbiological sampling was performed. The relatedness of the isolates was determined using draft-whole-genome sequencing.ResultsCPE surveillance cultures of patients and environments were positive in 19 patients and 9 sinks in the ward. The sinks in hospital rooms uninhabited by CPE patients exhibited no positive CPE-positive specimen during the outbreak. All CPE strains analyzed using draft-whole-genome sequencing harbored blaIMP-1, except for one harboring blaIMP-11; these strains harbored identical blaIMP-1-carrying IncM1 plasmids. CPE was detected even after sink replacement; infection-control measures focused on sinks were implemented and the CPE outbreak ended after 7 months.ConclusionsMultiple bacterial species can become CPE via blaIMP-1-carrying IncM1 plasmids of the same origin and spread through sinks in a hospital ward. Thorough infection-control measures implemented as a bundle might be crucial. This study describes an outbreak caused by multispecies carbapenemase-producing Enterobacterales (CPE) occurring in a pediatric ward at an academic medical center in Tokyo. The index case involved a 1-year-old boy with Klebsiella variicola (CPE) detected in anal swabs in June 2016. The second case was Klebsiella quasipneumoniae (CPE) occurred in March 2017 followed by further spread, leading to the declaration of an outbreak in April 2017. Extensive environmental and patient microbiological sampling was performed. The relatedness of the isolates was determined using draft-whole-genome sequencing. CPE surveillance cultures of patients and environments were positive in 19 patients and 9 sinks in the ward. The sinks in hospital rooms uninhabited by CPE patients exhibited no positive CPE-positive specimen during the outbreak. All CPE strains analyzed using draft-whole-genome sequencing harbored blaIMP-1, except for one harboring blaIMP-11; these strains harbored identical blaIMP-1-carrying IncM1 plasmids. CPE was detected even after sink replacement; infection-control measures focused on sinks were implemented and the CPE outbreak ended after 7 months. Multiple bacterial species can become CPE via blaIMP-1-carrying IncM1 plasmids of the same origin and spread through sinks in a hospital ward. Thorough infection-control measures implemented as a bundle might be crucial.