Hospital Drains as Reservoirs of Pseudomonas aeruginosa: Multiple-Locus Variable-Number of Tandem Repeats Analysis Genotypes Recovered from Faucets, Sink Surfaces and Patients

Abstract

Identifying environmental sources of Pseudomonas aeruginosa (Pa) related to hospital-acquired infections represents a key challenge for public health. Biofilms in water systems offer protection and favorable growth conditions, and are prime reservoirs of microorganisms. A comparative genotyping survey assessing the relationship between Pa strains recovered in hospital sink biofilm and isolated in clinical specimens was conducted. Environmental strains from drain, faucet and sink-surface biofilm were recovered by a culture method after an incubation time ranging from 48 to 240 h. The genotyping of 38 environmental and 32 clinical isolates was performed using a multiple-locus variable-number of tandem repeats analysis (MLVA). More than one-third of Pa isolates were only cultivable following ≥48 h of incubation, and were predominantly from faucet and sink-surface biofilms. In total, 41/70 strains were grouped within eight genotypes (A to H). Genotype B grouped a clinical and an environmental strain isolated in the same ward, 5 months apart, suggesting this genotype could thrive in both contexts. Genotype E grouped environmental isolates that were highly prevalent throughout the hospital and that required a longer incubation time. The results from the multi-hospital follow-up study support the drain as an important reservoir of Pa dissemination to faucets, sink surfaces and patients. Optimizing the recovery of environmental strains will strengthen epidemiological investigations, facilitate pathway identification, and assist in identifying and controlling the reservoirs potentially associated to hospital-acquired infections.

Sink traps as the source of transmission of OXA-48–producing Serratia marcescens in an intensive care unit

“…11,12 . Most reports on CRO outbreaks related to a water reservoir describe Pseudomonas spp or Acinetobacter baumannii outbreaks, 9,[12][13][14] with only a few CPE outbreaks directly related to water reservoirs, including a KPC-2 producing K. oxytoca, 15 IMP-4-producing Enterobacter cloacae, 16 KPC-2-producing K. pneumoniae, 17 and recently, OXA-48-producing C. freundii. 18 The Serratia species is known to survive and grow in moist environments.…”

Antimicrobial resistance patterns and genotypic diversity between clinical and water systems isolates of Pseudomonas aeruginosa in Cali, Colombia

“…In recent years the circulation of strains has increased resistant to carbapebemes and to other antimicrobials, has led to the emergence of multidrug-resistant P. aeruginosa (MDRPA). P. aeruginosa can grow in many environments, it is found in water, soil, sewage, animal faeces, on vegetation and the human body and has a great capacity to adapt to the environment, survive extremes which includes temperatures ranging from 4°C to 43°C, and weak ion concentrations, among others (Wu et al, 2012;Lalancette et al, 2017).…”

Carbapenem-resistant Enterobacteriaceae dispersal from sinks is linked to drain position and drainage rates in a laboratory model system

“…It has been known for over 20 years that hospital sinks and drains can support long-term persistence of multidrugresistant Enterobacteriaceae [4,5] and other Gram-negative organisms, including Pseudomonas aeruginosa [6]. More recently and in several hospitals, sinks, drains and waste traps have been found to harbour identical or very similar CRE strains as those colonizing and infecting patients [7e16].…”