Biofilm contamination of high-touched surfaces in intensive care units: epidemiology and potential impacts.

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PubMed ID: 30758060

Imagen Publicación

de Melo Costa D, Johani K, Melo DS, de Oliveira Lopes LK, de Oliveira Lopes Lima LK, Tipple AFV, Hu H, Vickery K

Lett Appl Microbiol. Feb 2019. doi: 10.1111/lam.13127

COMMENT: Healthcare-associated infections are a public health problem in hospitals, particularly in intensive care units (ICUs). Previous studies have demonstrated the presence of viable microorganisms on hospital surfaces, especially in the frequently touched site. Recently, pathogenic bacteria have been detected in biofilms contaminating dry hospital surfaces. This study provides a complete epidemiology survey from ICUs from two large public Brazilian hospitals including microbiome analysis by 16S rRNA amplicon sequencing and detection of multidrug resistant organisms (MROs).


In this study, bacterial contamination on ICUs surfaces, in Brazil, a upper-middle income country (The World Bank, 2018), was investigated by determining the epidemiology (location, microbial load, microbiome, presence or absence of biofilm, and pathogens, including ESKAPE - Enterococcus faecium, Staphylococcus aureus, Klebsiella pneumoniae, Acinetobacter baumannii, Pseudomonas aeruginosa and Enterobacter species – organisms, and antimicrobial susceptibility profiles) of the bacterial contamination.

Main results

Next generation sequencing of 27 samples showed a large microbial diversity, more than 830 Operational Taxonomic Units (OTUs) and 170 genera.

The overall composition of the bacterial community varied significantly between hospitals, in that on average 73% of pooled samples from hospital 1 (Goiás) ICU biofilm was composed of environmental bacteria with a dominance of Acinetobacter and Pseudomonas, while 65% at hospital 2 (Pará) were composed of human microbiota with a dominance of Staphylococcus.

ESKAPE organisms were detected in 51.8% of the samples subjected to next generation sequencing. A. baumannii, S. aureus, Enterobacter sp and P. aeruginosa were detected in 11 (six culture positive and five culture negative), four (three culture positive and one culture negative ), two (culture negative) and one (culture negative) samples.

Next generation sequencing showed that two samples, a computer keyboard and a eletrocardiogram machine keypad, from hospital 2 surgical/clinical adult ICU were concomitantly contaminated by S. aureus and A. baumannii; and S. aureus, A. baumannii and P. aeruginosa, respectively. MROs were also sourced from telephone keys and computer keyboard


High-touched surfaces of ICUs were found to be contaminated with clinical important pathogenic bacteria, including MROs. The higher amount of samples positive by qPCR compared to culture suggests the presence of non-culturable bacteria such as those found in biofilm formed on dry surfaces. Further investigation is required to verify the transmissibility risk for biofilm bacteria on ICU surfaces to patient.


Diana López-Farfán