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BMC Proceedings

Open Access

Microbial load in instruments used in surgeries classified as clean

  • FMG Pinto1,
  • GADA Moriya1, 2 and
  • KU Graziano1
BMC Proceedings20115(Suppl 6):P313

Published: 29 June 2011

Introduction / objectives

The number of orthopedic surgery, especially surgery of total hip and knee, have been more frequent due to technological advances. This study aims to determine the microbial load in the instruments used in clean surgeries, quantifying and identifying the genus and species of microbial growth.


Orthopedic surgical instruments were immersed, after use, in sterile water, sonicated in ultrasonic washer and consecutively shaken. Then, the lavage was filtered through a 0.45micron membrane, the result was incubated in aerobic medium, anaerobic medium and medium for fungi and yeasts.


In clean surgeries, results showed that 47% of used instruments had microbiological growth in the range of 1 to 100 CFU/instrument. The most prevalent organism was Staphylococcus coagulase negative (28%), followed by Bacillus subtilis (11%).This study refuted the hypothesis that clean surgeries happen in micro-organismsfree surgery field.


The microbiological findings reinforce the importance of antibiotic prophylaxis, practice already well established for this category of surgical procedure.

Disclosure of interest

None declared.

Authors’ Affiliations

Departamento de Enfermagem Médico-Cirúrgica, Nursing School – University of Sao Paulo
CSSD, Hospital Alemão Oswaldo Cruz


© Pinto et al; licensee BioMed Central Ltd. 2011

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.