title: Multidrug-resistant organisms in a routine ward environment: differential propensity for environmental dissemination and implications for infection control.
abstract: Multidrug-resistant organisms (MDROs) pose significant infection-control challenges in settings with high prevalence and limited isolation facilities. This observational study in an 800-bed hospital determined the prevalence, bacterial density and genetic relatedness of MDROs isolated from ward surfaces, medical devices and the hands of healthcare professionals. The targeted MDROs were meticillin-resistant Staphylococcus aureus (MRSA), vancomycin-resistant enterococci (VRE), Escherichia coli and Klebsiella pneumoniae resistant to extended-spectrum cephalosporins, and carbapenem-resistant (CR) Acinetobacter baumannii. During a 2-month period, microbiological sampling and molecular typing were performed on environment isolates, clinical isolates and isolates recovered from the hands of healthcare professionals. The target MDROs were recovered from 79% of sampled surfaces, predominantly MRSA (74% of all tested surfaces) and CR A. baumannii (29%) but also VRE (2%) and K. pneumoniae (1%). MRSA was recovered from most tested surfaces throughout the ward, whilst CR A. baumannii was significantly more likely to be recovered from near-patient surfaces. Hand sampling demonstrated infrequent recovery of MRSA (5%), CR A. baumannii (1%) and VRE (1%). Molecular typing of the study isolates identified seven MRSA and five Acinetobacter clonal clusters, respectively, and typing identified similar strains from the environment, patients and hands. Thus, in a healthcare setting with endemic circulation of MDROs, MRSA and CR A. baumannii were the predominant organisms recovered from ward surfaces, with MRSA in particular demonstrating widespread environmental dissemination. Molecular typing demonstrated the presence of related strains in patients, in the environment and on the hands of healthcare workers.
authors: Department of Laboratory Medicine, Changi General Hospital, Singapore.
authors: Thean Yen
authors: TY
authors: Tan
authors: School of Life Sciences, Ngee Ann Polytechnic, Singapore.
authors: Jasmine Shi Min
authors: JSM
authors: Tan
authors: School of Life Sciences, Ngee Ann Polytechnic, Singapore.
authors: Huiyi
authors: H
authors: Tay
authors: Infection Control, Changi General Hospital, Singapore.
authors: Gek Hong
authors: GH
authors: Chua
authors: Department of Laboratory Medicine, Changi General Hospital, Singapore.
authors: Lily Siew Yong
authors: LSY
authors: Ng
authors: Clinical Trials and Research Unit, Changi General Hospital, Singapore.
authors: Nur
authors: N
authors: Syahidah
mesh_terms: D001419:Bacteria / Q000145:classification* / Q000187:drug effects*; D015373:Bacterial Typing Techniques; D024901:Drug Resistance, Multiple, Bacterial; D004783:Environmental Microbiology; D006225:Hand; D006757:Hospital Units; D006801:Humans; D017053:Infection Control / Q000379:methods*; D012867:Skin / Q000382:microbiology