A Model for Evaluating Topical Antimicrobial Efficacy against Methicillin-Resistant Staphylococcus aureus Biofilms in Superficial Murine Wounds

Abstract

A wound biofilm model was created by adapting a superficial infection model. Partial-thickness murine wounds were inoculated with methicillin-resistant Staphylococcus aureus (MRSA). Dense biofilm communities developed at the wound surface after 24 h as demonstrated by microscopy and quantitative microbiology. Common topical antimicrobial agents had reduced efficacy when treatment was initiated 24 h after inoculation compared to 4 h after inoculation. This model provides a rapid in vivo test for new agents to treat wound biofilm infections.

Newly Developed Topical Cefotaxime Sodium Hydrogels: Antibacterial Activity andIn VivoEvaluation

“…Roche et al reported that there was a >3-log reduction upon application of mupirocin and bacitracin topical antibiotics after 4 h of MRSA inoculation. These previously in vivo count results are consistent with the observed data from the killing diagram (Figure 10) [34]. …”

“…Consequently, the sections were stained using Hematoxylin and Eosin (H&E), and then they were dried overnight. The stained tissues were microscopically examined and the most detailed and clear tissue slides were chosen [34]. …”

Simultaneous monitoring of Staphylococcus aureus growth in a multi-parametric microfluidic platform using microscopy and impedance spectroscopy

“…Apart from disrupting bacterial wall biosynthesis, bacitracin provokes modifications in the permeability of the plasma membrane as the lipid is an integral component of the membrane [59,60]. Unlike other antibacterial compounds that only affect earlier phases in the biofilm formation such as mupirocin [61], bacitracin influences biofilm at any stage of the process. The effects that bacitracin has on biofilms are illustrated in Fig.…”

“…Numerous in vitro studies can be found in the literature based on the Bioelectrochemistry 105 (2015) [56][57][58][59][60][61][62][63][64] relative impedance changes induced after cell adhesion onto the electrodes [14,15], some of them using commercial interdigitated microelectrodes (IDuE) [16,17]. Despite offering a large sensitive area in a limited space, most of commercial IDuE do not offer the possibility of studying cell growth under flow conditions, a variable that is known to affect biofilm structure and behavior [18], or to measure additional cell culture parameters to control other cell cultures analytes of interest [19].…”

Biofilms and Wounds: An Overview of the Evidence

“…Roche et al 27 studied the development of biofilms on partial-thickness murine wounds infected with methicillin-resistant S. aureus (MRSA). Dense biofilm aggregates developed at the wound surface within 24 h following inoculation, as confirmed by microscopy.…”