Contribution of tap water to patient colonisation with Pseudomonas aeruginosa in a medical intensive care unit

Other Possible Causes of a Well-Publicized Outbreak of <i>Pseudomonas aeruginosa</i> Following Arthroscopy in Texas

“…Yet, improper reprocessing of reusable medical equipment-whether of a flexible endoscope, an arthroscopic instrument, or another type of medical instrument-is but only one of many factors documented to be responsible for infections of P. aeruginosa in the healthcare setting. For example, reports also describe infections of P. aeruginosa and other bacteria associated with poor hand hygiene or the contaminated hands (and fingernails) of healthcare workers; with the re-contamination of (unwrapped) instruments during their improper handling; and with hand-washing sinks colonized with bacteria [18,[23][24][25][26][27][28][29][30]. Like the studies by Voyles et al (1995) and Rutala et al (2008), these reports also lend credence to the possibility that, not necessarily the ineffective steam sterilization of the implicated arthroscopic instruments, but rather another factor-for example, the inadvertent failure to have sterilized the instruments using any method [31] 4 -might have contributed more to Methodist Hospital's outbreak than has been recognized.…”

“…Based on this result, Tosh et al (2011) conclude that the implicated arthroscopic instrumentation was most likely contaminated during the "gross decontamination 2) Bacterial contamination of the implicated arthroscopic instruments after successful sterilization-for example, during: their inadvertent contact with contaminated water, a contaminated sink (e.g., during splashing) or another contaminated environmental surface [27,29,30]; or, their improper handling by contaminated hands [23][24][25];…”

Hand Hygiene

“…78,79,94,[132][133][134][135][136][137][138][139][140][141][142] For example, in studies conducted before glove use was common among HCWs, Ayliffe and colleagues 137 found that 15% of nurses working in an isolation unit carried a median of 1x 10 4 CFU of S. aureus on their hands; 29% of nurses working in a general hospital had S. aureus on their hands (median count, 3.8 x 10 3 CFU), while 78% of those working in a hospital for dermatology patients had the organism on their hands (median count, 14.3 x 10 6 CFU). The same survey revealed that 17-30% of nurses carried Gram-negative bacilli on their hands (median counts ranged from 3.4 x 10 3 CFU to 38 x 10 3 CFU).…”

Characterization of the poxAB Operon Encoding a Class D Carbapenemase in Pseudomonas aeruginosa,

“…Specifically, a study found P. aeruginosa was able to not only grow but thrive in the distilled water of several mist therapy units (28). Tap water is also a major source of nosocomial infections when it is inadvertently used for the preparation of solutions to be used in that setting (29)(30)(31)(32)(33). The prevalence of P. aeruginosa in tap water likely results from the colonization of showerheads, faucets, and sinks from which it has also been detected (32,(34)(35)(36)(37)(38).…”

“…OprD is specific for basic amino acids, dipeptides and carbapenems (imipenem, meropenem, doripenem) (20,21,23,34). In the clinical setting, exposure to imipenem often leads to mutations, deletions or insertions in oprD and loss of the protein resulting in impermeability and clinical resistance to imipenem (29)(30)(31)(32)(33)38). Although loss of OprD also increases the MIC against meropenem, it does not by itself usually lead to clinical resistance (303)(304)(305), presumably because meropenem can also get inside the cells via other routes (306)(307)(308).…”