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  • Poster presentation
  • Open Access

Efficacy of HyperDRYmist® technology in reducing residual environmental MDR bacterial contamination in tertiary hospital

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Antimicrobial Resistance and Infection Control20154 (Suppl 1) :P41

  • Published:


  • Hard Surface
  • Active Chlorine
  • Stenotrophomonas Maltophilia
  • Enrich Broth
  • Hospital Room


Environmental persistence of multidrug-resistant (MDR) organisms in hospital environment is arduous to reduce or eliminate. Efficacy’s inconsistency characterizing manual disinfection that generates high levels of residual surface contamination compounds adversities in achieving reduction.


Study evaluated a novel no-touch disinfection technology named HyperDRYMist®, which decontaminates hard surfaces by delivering aerosolized enhanced Hydrogen Peroxide, as an addition to manual disinfection (terminal cleaning).


Hard surfaces of 20 hospital rooms occupied by patients affected by classic MDR bacteria prospectively sampled for contamination in 10 standardized high-touch points following patient’s discharge. Measurements taken after manual disinfection with active chlorine (2000 ppm), before micro-nebulization via HDM® and after it. Eventual residual bacterial contamination excluded by enriched broth culture.


For 8 months, prospectively identified and included 20 cases of “classic” MDR patients (see list below). After terminal cleaning, mean residual bacterial contamination was 59,27±78,89 (mean± SD) cfu/ml, with values reaching up to 400 cfu/ml, then reduced to 2,48±12,07 (p < 0.0001) after HDM®. Purposely searched for environmental presence of MDR after conventional cleaning. In 14/20 rooms MDRs bacteria still detected, in particular found MRSA in 4 of 4 rooms, Acinetobacter baumanii in 2/2, MDR Pseudomonas in 2/2, KPC in 2/4, VRE in 0/2, E.coli ESBL 2/2, K. pneumonia ESBL 0/2, Stenotrophomonas maltophilia 2/2. After HDM® in none of the rooms MDR bacteria detected.


Study confirms how significant levels of environmental contamination persist when solely manual disinfection is adopted to eradicate MDR bacteria from surfaces. In spite of quality certified protocols, overall inconsistency of results observed with degrees of efficacy clearly operator’s dependent. HDM® brought consistency of results in drastically reducing pathogens’ presence.

Persistence of MDRs in rooms sampled suggests surfaces may play pivotal role for HAI transmission, hence the advantages of disinfection technologies like HDM® in terminal cleaning procedures.

Disclosure of interest

None declared.

Authors’ Affiliations

Department of Hygiene, AO Lodi, “Maggiore” Hospital of Lodi, Lodi, Italy
Hospital Management, AO Lodi, “Maggiore” Hospital of Lodi, Lodi, Italy
Department of Microbiology, AO Lodi, “Maggiore” Hospital of Lodi, Lodi, Italy
Department of Internal Medicine and Infectious Diseases, Clinica Luganese, Lugano, Switzerland
Department of Infectious Diseases, Inselspital; Bern University Hospital and University of Bern, Bern, Switzerland


© Ferrari et al; licensee BioMed Central Ltd. 2015

This article is published under license to BioMed Central Ltd. This is an Open Access article distributed under the terms of the Creative Commons Attribution License (, which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited. The Creative Commons Public Domain Dedication waiver ( applies to the data made available in this article, unless otherwise stated.