Gerit D. Mulder, DPM, MS; Joseph P. Cavorsi, MD; Daniel K. Lee, DPM


Wounds. 2007;19(7):173-182. 

In This Article

Bacterial Imbalance

When wounds fail to heal or are classified as recalcitrant, one of the factors delaying healing that merits consideration is bacterial load in the wound bed and its effect on the tissue repair process.[5,6] All chronic wounds are believed to have some level of bacterial bioburden. Depending on the number of organisms, the level of bacteria in the wound bed may be classified as contaminated, colonized, critically colonized, or infected.[4,7] Contamination (the presence of organisms in a wound) and colonization (the proliferation of those organisms) are not routinely treated with oral or systemic antibiotics. Once a wound becomes critically colonized (a level of colonization affecting skin cell proliferation and tissue repair), it may progress to a "classic" infection, which may include erythema, cellulitis, edema, and increases in odor, pain, exudate, white blood cell count, and increased body temperature.[8]

Delayed closure may suggest the formation of an extracellular polysaccharide matrix film or layer (sometimes called a glycocalyx)9 that shields the bacteria from attack while maintaining the moist environment in which they thrive.[10] These colonies of bacteria are called biofilms and are produced by Pseudomonas aeruginosa, Klebsiella pneumoniae, Staphylococcus aureus, and E coli, among others. The biofilm makes it difficult to eliminate pathogens by requiring as much as 50-1000 times the minimal inhibitory concentration (MIC) of an antibiotic or antiseptic.[10]

Clinicians may attempt to address the bacterial imbalance by combining treatment modalities. To address infection in the wound bed systemic or oral antibiotics should be considered the first line of therapy, especially in complicated skin infections with clinical signs of cellulitis, leukocytosis, or fever.[11] In conjunction with systemic therapy, there are a number of antimicrobial dressings currently on the market indicated for use on infected wounds. Antimicrobial dressings are comprised of a variety of different base materials to which antimicrobial agents are added. The major purported benefits of these dressings are that they may reduce the presence of pathogens and decrease the risk of infection while creating a wound bed that will readily support the normal sequence of wound repair.


Comments on Medscape are moderated and should be professional in tone and on topic. You must declare any conflicts of interest related to your comments and responses. Please see our Commenting Guide for further information. We reserve the right to remove posts at our sole discretion.