The High Impact of Staphylococcus aureus Biofilm Culture Medium on In Vitro Outcomes of Antimicrobial Activity of Wound Antiseptics and Antibiotic

Abstract

The staphylococcal biofilm-based infections of wounds still pose a significant therapeutical challenge. Treated improperly, they increase the risk of limb amputation or even death of the patient. The present algorithms of infected wound treatment include, among others, the application of antiseptic substances. In vitro wound biofilm models are applied in order to scrutinize their activity. In the present work, using a spectrum of techniques, we showed how the change of a single variable (medium composition) in the standard in vitro model translates not only to shift in staphylococcal biofilm features but also to the change of efficacy of clinically applied wound antimicrobials such as octenidine, polyhexamethylene biguanide, chlorhexidine, hypochlorite solutions, and locally applied gentamycin. The data presented in this study may be of a pivotal nature, taking into consideration the fact that results of in vitro analyses are frequently used to propagate application of specific antimicrobials in hospitals and ambulatory care units.

The effects of rotating magnetic field and antiseptic on in vitro pathogenic biofilm and its milieu

“…In the case of the experimental model applied in this research, the milieu is microbiological medium and agar discs. As we already indicated in our earlier work 2 , the plethora of organic compounds in applied TSB medium, derived from hydrolyzate of casein and soybean, may have an impact on cationic octenidine dihydrochloride. In fact, the normative methods of assessment of antiseptic activity imply the use of an “organic burden” to analyze the impact of this load on antiseptic molecules' activity, which is mostly negative (the effectiveness drops) 57 .…”

“…To analyze the antibiofilm activity of the OCT released from the carrier, the Antibiofilm Dressing’s Activity Measurement (A.D.A.M) test was performed according to the protocol originally devised in our laboratory 2 , 22 with minor modifications (concerning the concentration of microorganisms and the size of the agar discs). Briefly, P. aeruginosa ATCC 15442 and S. aureus ATCC 6538 colonies grown on the Columbia Agar (containing 5% sheep blood medium) were transferred into 5 mL of Tryptic Soy Broth (TSB) medium and incubated for 24 h at 37 °C with shaking (200 rpm).…”

“…This multi-cellular society of aggregated microorganisms is enclosed within a self-produced extracellular matrix (ECM). The matrix may account for even 90% of biofilm’s dry mass and may consist of proteins, glycoproteins, polysaccharides, and extracellular DNA 1 , 2 in various proportions. The ECM provides bacteria protection, nutrition source, and the environment in which virulence factors or messenger molecules are interchanged rapidly and effectively.…”

The efficacy of antiseptic agents against staphylococcal biofilm can be quantitatively assessed with the use of processed microscopic images

“…If “younger” and “older” biofilms were included to the investigation line, also other patterns of cellular density, biofilm thickness and L/D-dyed cell spatial composition would be probably detected. Secondly, just one type of culturing medium (Tryptic Soy Broth) was applied, while high differences in biofilm structures formed by the same strain, but cultured in different media, were already observed [27] . Thirdly, only polystyrene surface was used to culture biofilms, while the impact of various surface types on biofilm structure is undisputable and proven [28] .…”

The In Vitro Ability of Klebsiella pneumoniae to Form Biofilm and the Potential of Various Compounds to Eradicate It from Urinary Catheters

“…Depending on the time of formation, species characteristics and environmental conditions, the size of such biofilm may range from a few microns to several millimeters in thickness. Fragments of mature biofilm may detach from the surface and migrate through blood vessels to distant parts of the body, causing generalized infections and leading to the formation of new biofilm in other locations [15,16]. The most common causes of nosocomial infections are biofilms formed on urological and vascular catheters, various kinds of endoprostheses, artificial heart valves, peritoneal dialysis catheters, as well as on artificial ventilation equipment and infusion pumps.…”