Effectiveness of manual versus automated cleaning on Staphylococcus epidermidis biofilm removal from the surface of surgical instruments

Published:October 17, 2019DOI:


      • Bacterial adhesion forming a multilayer on surgical forceps can occurs in 1 hour.
      • Automated cleaning remove microbial load better than manual cleaning.
      • Microbial loads recovered from jaw and ratchet were higher compared to shank.
      • Structural damage on forceps may act as sites for microbial adhesion and shelter.


      Biofilm removal is a challenge during surgical instrument processing. We analyzed the time required for Staphylococcus epidermidis to form biofilms on surgical instruments, and how cleaning methods removed them.


      Different areas (ratchet, shank, and jaw) of straight crile forceps were contaminated by soaking in Tryptic Soy Broth containing 106 colony forming units (CFU)/mL of S epidermidis for 1, 2, 4, 6, 8, and 12 hours. S epidermidis adhesion and removal, after manual or automated ultrasonic cleaning, was evaluated by microbiological culture and scanning electron microscopy.


      Microbial load increased with time (101-102 CFU/cm2 after 1 hour; 104 CFU/cm2 after 12 hours). Exopolysaccharide was detected after 2 hours and gradually increased thereafter. Bacterial load was reduced by 1-2 log10 after manual cleaning and 1-3 log10 after automated cleaning, but biofilms were not completely eliminated. In general, bacterial load was lower in shank fragments. This difference was significant at 6 hours.


      Rapid adhesion of S epidermidis and exopolysaccharide formation was observed on surgical instruments. Automated cleaning was more effective than manual cleaning, but neither method removed biofilms completely. The precleaning conditions and the forceps design are critical factors in processing quality.

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        • World Health Organization
        Decontamination and reprocessing of medical devices for health-care facilities.
        World Health Organization, Geneva, Switzerland2016
        • Caston-Gaa A
        • Ruparelia CS
        Module 6. Processing surgical instruments and medical device.
        in: Curless MS Ruparelia CS Thompson E Trexler PA Infection prevention and control: reference manual for health care facilities with limited resources. Jhpiego, Baltimore (MD)2018.: 92.
        • Brasil Agencia Nacional de Vigilância Sanitária–ANVISA
        Ministério da Saúde. Resolução da Diretoria Colegiada N° 15, de 15 de março de 2012. Dispõe sobre os requisitos de boas práticas para o processamento de produtos para a saúde e da outras providências.
        2012 (Brasília (DF): Brasília)
        • Association of Perioperative Registered Nurses
        Guidelines for perioperative practice.
        AORN, Denver (CO)2017
        • Sheitoyan-Pesant C
        • Alarie I
        • Iorio-Morin C
        • Mathieu D
        • Carignan A
        An outbreak of surgical site infections following craniotomy procedures associated with a change in the ultrasonic surgical aspirator decontamination process.
        Am J Infect Control. 2017; 45: 433-435
        • Lopes LKO
        • Costa DM
        • Tipple AFV
        • Watanabe E
        • Castillo RB
        • Hu H
        • et al.
        Complex design of surgical instruments as barrier for cleaning effectiveness, favouring biofilm formation.
        J Hosp Infect. 2019; 103 (e55-60)
        • Costa DM
        • Lopes LKO
        • Tipple AFV
        • Johani K
        • Hu H
        • Deva AK
        • et al.
        Evaluation of stainless steel surgical instruments subjected to multiple use/processing.
        Inf Dis Health. 2018; 23: 3-9
        • Southworth PM
        Infections and exposures: reported incidents associated with unsuccessful decontamination of reusable surgical instruments.
        J Hosp Infect. 2014; 88: 127-131
        • Roberts CG.
        The role of biofilms in reprocessing medical devices.
        Am J Infect Control. 2013; 41: 77-80
        • Boari CA
        • Alves M
        • Tebaldi VMR
        • Savian TV
        • Piccoli RH
        Formação de biofilme em aço inoxidável por aeromonas hydrophila e Staphylococcus aureus usando leite e diferentes condições de cultivo.
        Food Sci Technol. 2009; 29: 886-895
        • Vickery K
        • Pajkos A
        • Cossart Y
        Removal of biofilm from endoscopes: evaluation of detergent efficiency.
        Am J Infect Control. 2004; 32: 170-176
        • Rutala WA
        • Weber DJ.
        Guideline for disinfection and sterilization in healthcare facilities.
        Center for Disease Control and Prevention, Atlanta (GA)2008
        • Costerton JW
        • Stewart PS
        • Greenberg EP
        Bacterial biofilms: a common cause of persistent infections.
        Science. 1999; 284: 1318-1322
        • Becker K
        • Heilmann C
        • Peters G
        Coagulase-negative staphylococci.
        Clin Microbiol Rev. 2014; 27: 870-926.
        • Public Health England
        Surveillance of surgical site infections in NHS hospitals in England, 2017/18.
        December 2018 (Available from) (Accessed May 15, 2019)
        • Evangelista SS
        • Santos SG
        • Stoianoff MAR
        • Oliveira AC
        Analysis of microbial load on surgical instruments after clinical use and following manual and automated cleaning.
        Am J Infect Control. 2015; 43: 522-527
        • Saito Y
        • Kobayashi H
        • Uetera Y
        • Yasuhara H
        • Kajiura T
        • Okubo T
        Microbial contamination of surgical instruments used for laparotomy.
        Am J Infect Control. 2014; 42: 43-47
        • Dower R
        • Turner ML.
        Pilot study of timing of biofilm formation on closed suction wound drains.
        Plast Reconstr Surg. 2012; 130: 1141-1146
        • Stoodley P,
        • Sidhu S
        • Nistico L
        • Mather M
        • Boucek A
        • Hall-Stoodley L
        • et al.
        Kinetics and morphology of polymicrobial biofilm formation on polypropylene mesh.
        FEMS Immunol Med Microbiol. 2012; 65: 283-290
        • Li X
        • Ji G.
        Evaluation of the relationship between bacterial load on contaminated stainless steel surgical instruments and the holding time prior to disinfection and also to analyse the efficacy of different disinfecting solutions.
        Biomed Res. 2017; 28: 4680-4687
        • Gottenbos B
        • Van Der Mei HC
        • Busscher HJ
        Initial adhesion and surface growth of Staphylococcus epidermidis and Pseudomonas aeruginosa on biomedical polymers.
        J Biomed Mater Res. 2000; 50: 208-214
        • Costa DM
        • Lopes LKO
        • Hu H
        • Tipple AFV
        • Vickery K
        Alcohol fixation of bacteria to surgical instruments increases cleaning difficulty and may contribute to sterilization inefficacy.
        Am J Infect Control. 2017; 45: e81-e86
        • Prior F
        • Fernie K
        • Renfrew A
        • Heneaghan G
        Alcoholic fixation of blood to surgical instruments—a possible factor in the surgical transmission of CJD?.
        J Hosp Inf. 2004; 58: 78-80
        • Lipscomb IP
        • Pinchin H
        • Collin R
        • Keevil CW
        Effect of drying time, ambient temperature and pre-soaks on prion-infected tissue contamination levels on surgical stainless steel: concerns over prolonged transportation of instruments from theatre to central sterile service departments.
        J Hosp Infect. 2007; 65: 72-77
        • Secker TJ
        • Hervé R
        • Keevil CW
        Adsorption of prion and tissue proteins to surgical stainless steel surfaces and the efficacy of decontamination following dry and wet storage conditions.
        J Hosp Infect. 2011; 78: 251-255
        • Chan-Myers H
        • Mcalister D
        • Antonoplos P
        Natural bioburden levels detected on rigid lumened medical devices before and after cleaning.
        Am J Infect Control. 1997; 25: 471-476
        • Otter JA
        • Vickery K
        • Walker JT
        • deLancey Pulcini E
        • Stoodley P
        • Goldenberg SD
        • et al.
        Surface-attached cells, biofilms and biocide susceptibility: implications for hospital cleaning and disinfection.
        J Hosp Infect. 2015; 89: 16-27