Molecular typing compared Pseudomonas aeruginosa isolates from water samples and hematology patient blood cultures, and found 3 patients with indistinguishable strains. The transmission event was likely due to cleaning an infusion therapy procedure tray with water from an outlet colonized with P. aeruginosa. Management of water, including holistic and engineering interventions, is needed to prevent transmission from water to patients.

During 2013-2014, 42 drinking water-associated outbreaks linked to 1006 cases of illness and 124 hospitalisations were reported to the CDC. Legionella spp. was associated with 24 (57%) of the outbreaks, and 100% of the deaths (13).

Wash hand basins are well recognised as reservoirs which facilitate patient colonization / infection with multi-drug resistant Gram negative bacteria (MDR-GNB). In this study, the impact of removing patient sinks on the annual rates of ICU-acquired MDR-GNB were assessed over a 6 year period. The incidence rates of MDR-GNB were 9.15 vs 2.20 per 1000 patient days in the pre- and post-sink removal periods respectively. The data support the high contribution of sink use with patient colonization and infection rates.

Many countries monitor water systems for presence of Legionellae, however limited information is available on individual species since most investigations focus on Legionella pneumophila. In this report, 76220 samples from 13397 warm water systems across southern Germany were examined, and 47924 Legionella isolates were identified. Approximately 21% of samples were positive for Legionella species, with 14 species recovered. Legionella pneumophila represented 84% of contaminations, although its proportion varied (57-91%) depending on geographical region. Legionella londiniensis represented approximately 39% of recovered colonies. The influence of temperature on species was disparate, although temperature ranges between 50–59 oC (122–138 oF) was identified as optimal for the majority of recovered Legionella species.

The VBNC state of Pseudomonas aeruginosa has been linked to copper ion concentrations relevant to those in drinking water systems. This study found that resuscitated P. aeruginosa were viable and regained cyto- / genotoxicity and therefore may impact health.

Multidrug-resistant Gram-negative BCC are rarely reported in non-cystic fibrosis patients. This study identified 248 patients with BCC blood stream infections who were of advanced age, chronically ill, and had severe disease. Common sources were central venous catheters (41%) and pneumonia (20%), with most cases (90%) being hospital- or healthcare-acquired with high mortality rates.