Induction heating for eradicating <i>Staphylococcus epidermidis</i> from biofilm

Pijls, Bart G; Sanders, Ingrid M J G; Kujiper, Ed J; Nelissen, Rob G H H

doi:10.1302/2046-3758.94.bjr-2019-0274.r1

Cited by 22 publications

(23 citation statements)

References 40 publications

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“…A previous study by our group demonstrated that P. aeruginosa biofilm was more susceptible to ciprofloxacin after AMF treatment 22 . Pijls et al 24 , 35 reported similar results as was seen in this study, that there was an enhanced effect with AMF and antibiotics in Staphylococcus epidermidis and S. aureus biofilms on titanium alloy than with either treatment alone. One concern for the clinical adoption of AMF relates to therapeutic index, specifically the ability to reduce biofilm through thermal effects while minimizing neighboring tissue damage.…”

Section: Discussionsupporting

confidence: 88%

Alternating magnetic fields and antibiotics eradicate biofilm on metal in a synergistic fashion

Wang

Vachon

Prasad

et al. 2021

npj Biofilms Microbiomes

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Hundreds of thousands of human implant procedures require surgical revision each year due to infection. Infections are difficult to treat with conventional antibiotics due to the formation of biofilm on the implant surface. We have developed a noninvasive method to eliminate biofilm on metal implants using heat generated by intermittent alternating magnetic fields (iAMF). Here, we demonstrate that heat and antibiotics are synergistic in biofilm elimination. For Pseudomonas aeruginosa biofilm, bacterial burden was reduced >3 log with iAMF and ciprofloxacin after 24 h compared with either treatment alone (p < 0.0001). This effect was not limited by pathogen or antibiotic as similar biofilm reductions were seen with iAMF and either linezolid or ceftriaxone in Staphylococcus aureus. iAMF and antibiotic efficacy was seen across various iAMF settings, including different iAMF target temperatures, dose durations, and dosing intervals. Initial mechanistic studies revealed membrane disruption as one factor important for AMF enhanced antibacterial activity in the biofilm setting. This study demonstrates the potential of utilizing a noninvasive approach to reduce biofilm off of metallic implants.

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Section: Discussionsupporting

confidence: 88%

Alternating magnetic fields and antibiotics eradicate biofilm on metal in a synergistic fashion

Wang

Vachon

Prasad

et al. 2021

npj Biofilms Microbiomes

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“…This model has been described elsewhere. 17 , 18 The biofilm was grown by immersing the coupons in 300 ml of growth medium (brain heart infusion (BHI)), inoculated with S. aureus (single colony from agar plate) and incubated for seven days at 37°C. The growth medium was not changed during these seven days.…”

Section: Methodsmentioning

confidence: 99%

“…This temperature and duration were chosen as they were expected to be effective and practical while minimizing the risk of necrosis. 13 , 17 , 21 The thermal shock was delivered in a non-contact manner using a custom-built induction heater with non-contact infrared temperature control. This system has been validated and described previously ( Figure 1 ).…”

Section: Methodsmentioning

confidence: 99%

“…This system has been validated and described previously ( Figure 1 ). 17 , 18 In short, the induction heater with a pancake-type coil creates a pulsed electromagnetic field (PEMF) of 97 kHz at a maximum of 65 W to heat the Ti6Al4V coupon in a petri dish that is placed above the pancake coil. The PEMF induces so-called ‘eddy currents’ in the metal (Ti6Al4V) coupon, which cause it to heat up.…”

Section: Methodsmentioning

confidence: 99%

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Effectiveness of mechanical cleaning, antibiotics, and induction heating on eradication of Staphylococcus aureus in mature biofilms

Pijls

Sanders

Kuijper

et al. 2022

Bone & Joint Research

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Aims Here we used a mature seven-day biofilm model of Staphylococcus aureus, exposed to antibiotics up to an additional seven days, to establish the effectiveness of either mechanical cleaning or antibiotics or non-contact induction heating, and which combinations could eradicate S. aureus in mature biofilms. Methods Mature biofilms of S. aureus (ATCC 29213) were grown on titanium alloy (Ti6Al4V) coupons for seven days and were subjected to the following treatments or their combinations: antibiotics, mechanical cleaning, or heat shock by induction heating of 60°C for one minute. Experiments were repeated at least five times. Results In the untreated biofilm, growth up to 1.8×1011 colony-forming units (CFU)/cm2 was observed. Treatment with ciprofloxacin, flucloxacillin, vancomycin, cefuroxime, and amoxicillin all with rifampicin gave 6.0 log, 6.1 log, 1.4 log, 4.8 log, and 3.6 log reduction in CFU/cm2, respectively. Mechanical cleaning alone resulted in 4.9 log reduction and induction heating in 7.3 log reduction. There was an additional effect of ciprofloxacin, flucloxacillin, and induction heating when used in combinations. There was no additional effect for mechanical cleaning. No bacterial growth could be detected after induction heating followed by seven days of ciprofloxacin with rifampicin. Conclusion Mechanical cleaning, antibiotics, and non-contact induction heating reduced the bacterial load of mature S. aureus biofilms with approximately 5 log or more as a single treatment. The effect of mechanical cleaning on mature S. aureus biofilms was limited when used in combination with antibiotics and/or induction heating. Cite this article: Bone Joint Res 2022;11(9):629–638.

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“…3,4 In addition to biofilm formation on implants, these bacteria can spread into bone matrix and the bone cells, causing inflammation and thereby interfering with the normal bone healing process. [5][6][7] Currently, new methods are being tested for treatment of biofilm-associated bone infection, namely the use of bone cement loaded with circulating drugs, 8 use of shockwaves, 9 and heat induction in combination with antibiotics. 10 Previously, S. aureus was considered an extracellular pathogen.…”

Section: Introductionmentioning

confidence: 99%

Rifampicin restores extracellular organic matrix formation and mineralization of osteoblasts after intracellular Staphylococcus aureus infection

Alagboso

Mannala

Walter

et al. 2022

Bone & Joint Research

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Aims Bone regeneration during treatment of staphylococcal bone infection is challenging due to the ability of Staphylococcus aureus to invade and persist within osteoblasts. Here, we sought to determine whether the metabolic and extracellular organic matrix formation and mineralization ability of S. aureus-infected human osteoblasts can be restored after rifampicin (RMP) therapy. Methods The human osteoblast-like Saos-2 cells infected with S. aureus EDCC 5055 strain and treated with 8 µg/ml RMP underwent osteogenic stimulation for up to 21 days. Test groups were Saos-2 cells + S. aureus and Saos-2 cells + S. aureus + 8 µg/ml RMP, and control groups were uninfected untreated Saos-2 cells and uninfected Saos-2 cells + 8 µg/ml RMP. Results The S. aureus-infected osteoblasts showed a significant number of intracellular bacteria colonies and an unusual higher metabolic activity (p < 0.005) compared to uninfected osteoblasts. Treatment with 8 µg/ml RMP significantly eradicated intracellular bacteria and the metabolic activity was comparable to uninfected groups. The RMP-treated infected osteoblasts revealed a significantly reduced amount of mineralized extracellular matrix (ECM) at seven days osteogenesis relative to uninfected untreated osteoblasts (p = 0.007). Prolonged osteogenesis and RMP treatment at 21 days significantly improved the ECM mineralization level. Ultrastructural images of the mineralized RMP-treated infected osteoblasts revealed viable osteoblasts and densely distributed calcium crystal deposits within the extracellular organic matrix. The expression levels of prominent bone formation genes were comparable to the RMP-treated uninfected osteoblasts. Conclusion Intracellular S. aureus infection impaired osteoblast metabolism and function. However, treatment with low dosage of RMP eradicated the intracellular S. aureus, enabling extracellular organic matrix formation and mineralization of osteoblasts at later stage. Cite this article: Bone Joint Res 2022;11(5):327–341.

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Induction heating for eradicating Staphylococcus epidermidis from biofilm

Cited by 22 publications

References 40 publications

Alternating magnetic fields and antibiotics eradicate biofilm on metal in a synergistic fashion

Alternating magnetic fields and antibiotics eradicate biofilm on metal in a synergistic fashion

Effectiveness of mechanical cleaning, antibiotics, and induction heating on eradication of Staphylococcus aureus in mature biofilms

Rifampicin restores extracellular organic matrix formation and mineralization of osteoblasts after intracellular Staphylococcus aureus infection

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