Association between Contaminated Faucets and Colonization or Infection by Nonfermenting Gram-Negative Bacteria in Intensive Care Units in Taiwan

Abstract

This study was designed to determine the strength of the association between the isolation of nonfermentative gram-negative bacilli (NFGNB) from tap water faucet aerators and the prevalence of colonization or infection of patients in intensive care units (ICUs). Surveillance cultures were obtained during a 4-month period from 162 faucet aerators located in seven different ICUs. The prevalence of colonization or infection of ICU patients with NFGNB was determined by prospective surveillance during the same period. Fifty four (33%) of the faucet aerators contained NFGNB. Among the 66 NFGNB isolated from faucet aerators, the most frequently encountered ones were Sphingomonas paucimobili (26 isolates), Pseudomonas aeruginosa (14 isolates), Chryseobacterium meningosepticum (13 isolates), Achromobacter xylosoxidans (6 isolates), Burkholderia cepacia (4 isolates), and Stenotrophomonas maltophilia (3 isolates). Acinetobacter baumannii was not recovered. The most common NFGNB isolated from ICU patients were P. aeruginosa and A. baumannii. There was a significant correlation between the overall prevalence of NFGNB in faucet aerators and their prevalence in exposed ICU patients (Spearman r ‫؍‬ 0.821, P ‫؍‬ 0.02). There was also a significant correlation between the prevalence of C. meningosepticum in faucet aerators and its prevalence among ICU patients (Spearman r ‫؍‬ 0.847, P ‫؍‬ 0.016). The electrokaryotypes of four clinical isolates of C. meningosepticum were similar to those of faucet isolates. Measures directed at making the water supply safe may prevent infection by C. meningosepticum and other waterborne pathogens.Nosocomial infections caused by nonfermentative gram-negative bacilli (NFGNB) are increasing in intensive care units (ICUs) (19,20,27). Pseudomonas aeruginosa, Acinetobacter baumannii, and Stenotrophomonas maltophilia account for most endemic infections. Outbreaks by other NFGNB such as Chryseobacterium spp. and Sphingomonas spp. are particularly troublesome (19,20,27).Hospital water has been shown to be a significant source of health care-associated infections caused P. aeruginosa in ICUs (4,15,17,18,25,26). Trautmann et al. (24) reported that P. aeruginosa could be frequently recovered from tap water outlets in ICUs and that the same genotypes were recovered from colonized or infected patients (24). Anaissie et al. estimated that 1,400 deaths occur each year in the United States as a result of waterborne nosocomial pneumonias caused by P. aeruginosa (1). Chlorinated tap water in hospitals often contains low levels of Legionella, P. aeruginosa, other NFGNB, mycobacteria, and Aspergillus (2,7,23,24,29). Assurance of a safe water supply is therefore an essential component of infection control in ICUs.During a recent investigation to determine the source of an outbreak of multidrug-resistant A. baumannii in an ICU, we cultured tap water faucets. P. aeruginosa and numerous other NFGNB, including Chryseobacterium meningosepticum, A. xylosoxidans, and Sphingomonas paucimobilis, were recovered. A. baumannii co...

Stenotrophomonas maltophilia: an Emerging Global Opportunistic Pathogen

“…Seven intensive care units, including a neurosurgical ICU, a surgical ICU, a cardiac surgical ICU, a pediatric ICU, two medical ICUs, and a respiratory care unit, were sampled for the presence of NFGNB. PFGE and electrokaryotyping analyses revealed no similarity between the S. maltophilia, P. aeruginosa, B. cepacia, and A. xylosoxidans isolates from faucets and the corresponding species of clinical isolates (355). That study also reported a strong positive correlation between the presence of NFGNB in the hospital tap water and the prevalence of waterborne NFGNB in ICU patients (355).…”

“…PFGE and electrokaryotyping analyses revealed no similarity between the S. maltophilia, P. aeruginosa, B. cepacia, and A. xylosoxidans isolates from faucets and the corresponding species of clinical isolates (355). That study also reported a strong positive correlation between the presence of NFGNB in the hospital tap water and the prevalence of waterborne NFGNB in ICU patients (355). The findings of that study suggest that alternatives to the use of hospital tap water should be considered, including disinfection of the water supply, point-of-use water filtration, and the use of sterile water.…”

“…A recent report investigated the association between the prevalence of nonfermentative Gram-negative bacillus (NFGNB) species in hospital tap faucets and the colonization or infection of patients in intensive care units with these bacteria (355). Seven intensive care units, including a neurosurgical ICU, a surgical ICU, a cardiac surgical ICU, a pediatric ICU, two medical ICUs, and a respiratory care unit, were sampled for the presence of NFGNB.…”

Achromobacter xylosoxidans Infection Presenting as a Pulmonary Nodule Mimicking Cancer

“…A. xylosoxidans is an aerobic, motile, Gram-negative bacillus that is a nonfermenter and is catalase and oxidase positive. A. xylosoxidans is ubiquitous in aqueous environments and has been associated with well water (36), tap water (17,43), and swimming pools (33) as well as environmental bodies of water (41). It is also a prevalent nosocomial colonizer and has been isolated from multiple types of aqueous solutions found in the health care setting, such as nonbacteriostatic saline (24), dialysis solutions (33), contact lens solutions (15), intravenous CT contrast solutions (32), chlorhexidine gluconate solutions (35), and ultrasound gel (28).…”

“…It is also a prevalent nosocomial colonizer and has been isolated from multiple types of aqueous solutions found in the health care setting, such as nonbacteriostatic saline (24), dialysis solutions (33), contact lens solutions (15), intravenous CT contrast solutions (32), chlorhexidine gluconate solutions (35), and ultrasound gel (28). A. xylosoxidans also colonizes fomites such as mechanical ventilators (6), neonatal incubators (25,29), faucet aerators (17,43), intravenous catheters (1,17,20,24), epidural catheters (30), urinary catheters (29), intravascular pressure transducers (17), pacemaker leads (2,26,33,36), and extracorporeal membrane oxygenation machines (21).…”