Abstract:
BACKGROUND: Ralstonia species are Gram-negative bacilli of low virulence. These organisms are capable of causing
healthcare associated infections through contaminated solutions. In this study, we aimed to determine the source
of Ralstonia mannitolilytica bacteraemia in affected patients in a haemodialysis unit.
METHODS: Our laboratory noted an increase in cases of bacteraemia caused by Ralstonia mannitililytica between
May and June 2016. All affected patients underwent haemodialysis at the haemodialysis unit of an academic
hospital. The reverse osmosis filter of the haemodialysis water system was found to be dysfunctional. We collected
water for culture at various points of the dialysis system to determine the source of the organism implicated.
ERIC-PCR was used to determine relatedness of patient and environmental isolates.
RESULTS: Sixteen patients were found to have Ralstonia mannitolilytica bacteraemia during the outbreak period.
We cultured Ralstonia spp. from water collected in the dialysis system. This isolate and patient isolates were found
to have the identical molecular banding pattern.
CONCLUSIONS: All patients were septic and received directed antibiotic therapy. There was 1 mortality. The source
of the R. mannitolilytica infection in these patients was most likely the dialysis water as the identical organism was
cultured from the dialysis water and the patients. The hospital management intervened and repaired the dialysis
water system following which no further cases of R. mannitolilytca infections were detected. A multidisciplinary
approach is required to control healthcare associated infections such as these. Routine maintenance of water
systems in the hospital is essential to prevent clinical infections with R.mannitolilytica.
