Keywords
Abstract
Background. Contaminated hospital surfaces play a key role in the transmission of healthcare-associated infections (HAIs), particularly those caused by antimicrobial-resistant pathogens. Despite routine cleaning and disinfection, high-touch surfaces may remain reservoirs for multidrug-resistant organisms, including biofilm-forming Staphylococcus aureus.
Methods. An environmental surveillance study was conducted in a single-bed room of an Internal Medicine ward in a hospital in Northern Italy. High-touch surfaces in the near-patient area and room furniture were sampled twice daily over one week, before and after routine cleaning/disinfection with chlorine-based agents (0.1-0.5% Cl). Cleaning effectiveness was evaluated using aerobic colony count (ACC) and detection of S. aureus as indicators of environmental hygiene, applying accepted microbiological benchmarks (ACC < 5 CFU/cm²; S. aureus < 1 CFU/cm²). S. aureus isolates were characterized by PFGE, spa typing, antimicrobial susceptibility testing, and biofilm production assays.
Results. Mean ACC decreased significantly after cleaning/disinfection (10.06 ± 15.67 vs 2.89 ± 5.52 CFU/cm²; p < 0.001), with a substantial reduction in non-compliant samples. However, residual contamination persisted on high-touch surfaces. S. aureus was detected in 12/238 samples, including post-cleaning samples from the near-patient area. Molecular analysis identified four distinct strains; notably, a spa type t032 (MLST ST22) isolate−methicillin-resistant, multidrug-resistant, and a strong biofilm producer−persisted on the bedside table handle both before and after cleaning.
Conclusion. Routine cleaning and disinfection significantly reduce environmental bioburden but may not reliably eliminate biofilm-forming multidrug-resistant S. aureus from critical hand-contact surfaces. These findings highlight the need for continuous microbiological surveillance and targeted IPC interventions to address environmental reservoirs of antimicrobial resistance in healthcare settings
References
European Centre for Disease Prevention and Control. Point prevalence survey of healthcareassociated infections and antimicrobial use in European acute care hospitals. Stockholm: ECDC; 2024. Available at https://www.ecdc.europa.eu/en/publications-data/PPS-HAI-AMR-acute-care-europe-2022-2023. Accessed on: 16/09/2025.
Sartelli M, Bartoli S, Borghi F, Busani S, Carsetti A, Catena F, Cillara N, Coccolini F, Cortegiani A, Cortese F, Fabbri E, Foghetti D, Forfori F, Giarratano A, Labricciosa FM, Marini P, Mastroianni C, Pan A, Pasero D, Scatizzi M, Viaggi B, Moro ML. Implementation Strategies for Preventing Healthcare-Associated Infections across the Surgical Pathway: An Italian Multisociety Document. Antibiotics (Basel) 2023;12:521. https://doi.org/10.3390/antibiotics12030521.
European Centre for Disease Prevention and Control. Healthcare-associated infections: surgical site infections. In: ECDC. Annual epidemiological report for 2021–2022. Stockholm: ECDC; 2025. Available at https://www.ecdc.europa.eu/en/publications-data/healthcare-associated-infections-surgical-site-infections-annual-2. Accessed on: 16/09/2025.
Sticchi C, Alberti M, Artioli S, Assensi M, Baldelli I, Battistini A, Boni S, Cassola G, Castagnola E, Cattaneo M, Cenderello N, Cristina ML, De Mite AM, Fabbri P, Federa F, Giacobbe DR, La Masa D, Lorusso C, Marioni K, Masi VM, Mentore B, Montoro S, Orsi A, Raiteri D, Riente R, Samengo I, Viscoli C, Carloni R; Collaborative Group for the Point Prevalence Survey of healthcare-associated infections in Liguria. Regional point prevalence study of healthcare-associated infections and antimicrobial use in acute care hospitals in Liguria, Italy. J Hosp Infect 2018;99:8-16. https://doi.org/10.1016/j.jhin.2017.12.008.
Ministero della Salute. Piano Nazionale di Contrasto dell’Antimicrobico-Resistenza (PNCAR) 2022–2025; Ministero della Salute: Roma, Italy, 2022. Available at: https://www.salute.gov.it/new/sites/default/files/imported/C_17_pubblicazioni_3294_allegato.pdf. Accessed on: 16/09/2025.
Khan HA, Baig FK, Mehboob R. Nosocomial Infections: Epidemiology, Prevention, Control and Surveillance. Asian Pac J Trop Biomed 2017;7:478-82. https://doi.org/10.1016/j.apjtb.2017.01.019.
Hota B. Contamination, disinfection, and cross-colonization: are hospital surfaces reservoirs for nosocomial infection? Clin Infect Dis 2004;39:1182-9. https://doi.org/10.1086/424667.
Rutala WA, Weber DJ. Monitoring and improving the effectiveness of surface cleaning and disinfection. Am J Infect Control 2016;44:e69-76. https://doi.org/10.1016/j.ajic.2015.10.039.
Facciolà A, Pellicanò GF, Visalli G, Paolucci IA, Venanzi Rullo E, Ceccarelli M, D'Aleo F, Di Pietro A, Squeri R, Nunnari G, La Fauci V. The role of the hospital environment in the healthcare-associated infections: a general review of the literature. Eur Rev Med Pharmacol Sci 2019;23:1266-78. https://doi.org/10.26355/eurrev_201902_17020.
Weber DJ, Rutala WA, Miller MB, Huslage K, Sickbert-Bennett E. Role of hospital surfaces in the transmission of emerging health care-associated pathogens: norovirus, Clostridium difficile, and Acinetobacter species. Am J Infect Control 2010;38:S25-33. https://doi.org/10.1016/j.ajic.2010.04.196.
Attaway HH 3rd, Fairey S, Steed LL, Salgado CD, Michels HT, Schmidt MG. Intrinsic bacterial burden associated with intensive care unit hospital beds: effects of disinfection on population recovery and mitigation of potential infection risk. Am J Infect Control 2012;40:907-12. https://doi.org/10.1016/j.ajic.2011.11.019.
Kramer A, Schwebke I, Kampf G. How long do nosocomial pathogens persist on inanimate surfaces? A systematic review. BMC Infect Dis 2006;6:130. https://doi.org/10.1186/1471-2334-6-130.
Orlando P, Cristina ML, Dallera M, Ottria G, Vitale A, Badolati G. Surface disinfection: evaluation of the efficacy of a nebulization system spraying hydrogen peroxide. J Prev Med Hyg 2008;49:116-9.
Donskey CJ. Does improving surface cleaning and disinfection reduce health care-associated infections? Am J Infect Control 2013;41:S12-9. https://doi.org/10.1016/j.ajic.2012.12.010.
Sehulster L, Chinn RY; CDC; HICPAC. Guidelines for environmental infection control in health-care facilities. Recommendations of CDC and the Healthcare Infection Control Practices Advisory Committee (HICPAC). MMWR Recomm Rep 2003;52:1-42.
Dancer SJ. The role of environmental cleaning in the control of hospital-acquired infection. J Hosp Infect 2009;73:378-85. https://doi.org/10.1016/j.jhin.2009.03.030.
Dancer SJ. Hospital cleaning in the 21st century. Eur J Clin Microbiol Infect Dis 2011;30:1473-81. https://doi.org/10.1007/s10096-011-1250-x.
Cobrado L, Silva-Dias A, Azevedo MM, Rodrigues AG. High-touch surfaces: microbial neighbours at hand. Eur J Clin Microbiol Infect Dis 2017;36:2053-062. https://doi.org/10.1007/s10096-017-3042-4.
Huslage K, Rutala WA, Gergen MF, Sickbert-Bennett EE, Weber DJ. Microbial assessment of high-, medium-, and low-touch hospital room surfaces. Infect Control Hosp Epidemiol 2013;34:211-2. https://doi.org/10.1086/669092.
WHO Guidelines on Hand Hygiene in Health Care: First Global Patient Safety Challenge Clean Care Is Safer Care. Geneva: World Health Organization 2009.
Guh A, Carling P. Environmental Evaluation Working Group. Options for Evaluating Environmental Cleaning. CDC, 2010. Available at: https://www.cdc.gov/infection-control/media/pdfs/Toolkits-Environmental-Cleaning-Evaluation-2010-P.pdf. Accessed on: 3/12/2025.
Datta R, Platt R, Yokoe DS, Huang SS. Environmental cleaning intervention and risk of acquiring multidrug-resistant organisms from prior room occupants. Arch Intern Med 2011;171:491-4. https://doi.org/10.1001/archinternmed.2011.64.
Hacek DM, Ogle AM, Fisher A, Robicsek A, Peterson LR. Significant impact of terminal room cleaning with bleach on reducing nosocomial Clostridium difficile. Am J Infect Control 2010;38:350-3. https://doi.org/10.1016/j.ajic.2009.11.003.
Sanna T, Dallolio L, Raggi A, Mazzetti M, Lorusso G, Zanni A, Farruggia P, Leoni E. ATP bioluminescence assay for evaluating cleaning practices in operating theatres: applicability and limitations. BMC Infect Dis 2018;18:583. https://doi.org/10.1186/s12879-018-3505-y.
Dancer SJ. How do we assess hospital cleaning? A proposal for microbiological standards for surface hygiene in hospitals. J Hosp Infect 2004;56:10-5. https://doi.org/10.1016/j.jhin.2003.09.017.
Dancer SJ. Hospital cleaning: past, present, and future. Antimicrob Resist Infect Control 2023;12:80. https://doi.org/10.1186/s13756-023-01275-3.
Centers for Disease Control and Prevention (CDC). Environmental Cleaning Checklist. Available at: https://www.cdc.gov/hai/pdfs/toolkits/environmental-cleaning-checklist-10-6-2010.pdf. Accessed on: 3/12/2025.
Golding GR, Campbell J, Spreitzer D, Chui L. Pulse Field Gel Electrophoresis. In Methods and Protocols; Jordan K, Dalmasso M, Eds.; Springer: New York, NY, USA, 2015; Volume 1301, pp. 85-93.
Shopsin B, Gomez M, Montgomery SO, Smith DH, Waddington M, Dodge DE, Bost DA, Riehman M, Naidich S, Kreiswirth BN. Evaluation of protein A gene polymorphic region DNA sequencing for typing of Staphylococcus aureus strains. J Clin Microbiol 1999;37:3556-63. https://doi.org/10.1128/JCM.37.11.3556-3563.1999.
Harmsen D, Claus H, Witte W, Rothgänger J, Claus H, Turnwald D, Vogel U. Typing of methicillin-resistant Staphylococcus aureus in a university hospital setting by using novel software for spa repeat determination and database management. J Clin Microbiol 2003;41:5442-8. https://doi.org/10.1128/JCM.41.12.5442-5448.2003.
Cramton SE, Gerke C, Götz F. In vitro methods to study staphylococcal biofilm formation. Methods Enzymol 2001;336:239-55. https://doi.org/10.1016/s0076-6879(01)36593-x.
Stepanović S, Vuković D, Hola V, Di Bonaventura G, Djukić S, Cirković I, Ruzicka F. Quantification of biofilm in microtiter plates: overview of testing conditions and practical recommendations for assessment of biofilm production by staphylococci. APMIS 2007;115:891-9. https://doi.org/10.1111/j.1600-0463.2007.apm_630.x.
Carling PC, Huang SS. Improving healthcare environmental cleaning and disinfection: current and evolving issues. Infect Control Hosp Epidemiol 2013;34:507-13. https://doi.org/10.1086/670222.
Asadollahi P, Farahani NN, Mirzaii M, Khoramrooz SS, van Belkum A, Asadollahi K, Dadashi M, Darban-Sarokhalil D. Distribution of the Most Prevalent Spa Types among Clinical Isolates of Methicillin-Resistant and -Susceptible Staphylococcus aureus around the World: A Review. Front Microbiol 2018;9:163. https://doi.org/10.3389/fmicb.2018.00163.
Espadinha D, Faria NA, Miragaia M, Lito LM, Melo-Cristino J, de Lencastre H; Médicos Sentinela Network. Médicos Sentinela Network. Extensive dissemination of methicillin-resistant Staphylococcus aureus (MRSA) between the hospital and the community in a country with a high prevalence of nosocomial MRSA. PLoS One 2013;8:e59960. https://doi.org/10.1371/journal.pone.0059960.
Soliman RS, Phillips G, Whitty P, Edwards DH. Distribution of meticillin-resistant Staphylococcus aureus spa types isolated from health-care workers and patients in a Scottish university teaching hospital. J Med Microbiol 2009;58:1190-95. https://doi.org/10.1099/jmm.0.010132-0.
Viana AS, Tótola LPDV, Figueiredo AMS. ST105 Lineage of MRSA: An Emerging Implication for Bloodstream Infection in the American and European Continents. Antibiotics (Basel) 2024;13:893. https://doi.org/10.3390/antibiotics13090893.