Evaluation of a Stenotrophomonas maltophilia bacteremia cluster in hematopoietic stem cell transplantation recipients using whole genome sequencing

Abstract

Background Stenotrophomonas maltophilia ubiquitously occurs in the hospital environment. This opportunistic pathogen can cause severe infections in immunocompromised hosts such as hematopoietic stem cell transplantation (HSCT) recipients. Between February and July 2016, a cluster of four patients on the HSCT unit suffered from S. maltophilia bloodstream infections (BSI).MethodsFor epidemiological investigation we retrospectively identified the colonization status of patients admitted to the ward during this time period and performed environmental monitoring of shower heads, shower outlets, washbasins and toilets in patient rooms. We tested antibiotic susceptibility of detected S. maltophilia isolates. Environmental and blood culture samples were subjected to whole genome sequence (WGS)-based typing.ResultsOf four patients with S. maltophlilia BSI, three were found to be colonized previously. In addition, retrospective investigations revealed two patients being colonized in anal swab samples but not infected. Environmental monitoring revealed one shower outlet contaminated with S. maltophilia. Antibiotic susceptibility testing of seven S. maltophlia strains resulted in two trimethoprim/sulfamethoxazole resistant and five susceptible isolates, however, not excluding an outbreak scenario. WGS-based typing did not result in any close genotypic relationship among the patients’ isolates. In contrast, one environmental isolate from a shower outlet was closely related to a single patient’s isolate.ConclusionWGS-based typing successfully refuted an outbreak of S. maltophilia on a HSCT ward but uncoverd that sanitary installations can be an actual source of S. maltophilia transmissions.

Cluster of S. maltophilia among patients with respiratory tract infections at an intensive care unit

“…In this study, WGS was applied. It clearly showed the high genetic diversity among S. maltophilia in a single unit, which is in accordance with other studies [ 20 , 21 ]. Furthermore, it showed a dissemination of ST361.…”

Characterization of Novel Broad-Host-Range Bacteriophage DLP3 Specific to Stenotrophomonas maltophilia as a Potential Therapeutic Agent

“…Related to this high-level antibiotic resistance, S. maltophilia is also capable of tolerating biocides and harsh environments, which makes this bacterium difficult to eradicate from hospital settings. Nosocomial isolation sources for S. maltophilia include ultra-pure water, hemodialysis water, nebulizers, hand-washing soap, hospital antiseptic solution, chlorhexidine-cetrimide topical antiseptic solution, hypochlorite cleaners, triclosan, sodium dodecyl sulfate, and antiseptics containing quaternary ammonium compounds (Brooke, 2012;Kampmeier et al, 2017). Non-clinical multidrug resistant isolates of S. maltophilia have also been recovered from environments such as soil, water, plants and food sources (Berg et al, 2005;Qureshi et al, 2005;Brooke, 2012;Lin et al, 2017;Furlan and Stehling, 2018;Kim et al, 2018), and have the potential to cause community-acquired infections (Falagas et al, 2009;Chang et al, 2014).…”

Zinc Chelators as Carbapenem Adjuvants for Metallo-β-Lactamase-Producing Bacteria: In Vitro and In Vivo Evaluation

“…8,9 There has been an increased incidence of infections caused by these opportunistic bacteria in critical care settings during the last 5 years. [10][11][12] In recent years, interest in the use of zinc chelators as MBL inhibitors has been growing. 13,14 In fact, since MBL enzymes require one or two zinc ions for their activity, zinc chelators could act as zinc ''strippers'' from MBL enzymes, depriving them of anti-b-lactam activity, or as metal-binding competitive MBL inhibitor.…”