The Impact of Biofilm Formation on Wound Healing

An assortment of redox-active phenazine compounds like pyocyanin with their characteristic blue-green colour are synthesized by Pseudomonas aeruginosa, Gram-negative opportunistic pathogens, which are also considered one of the most commercially valuable microorganisms. In this study, pyocyanin from Pseudomonas aeruginosa BTRY1 from food sample was assessed for its antibiofilm activity by micro titer plate assay against strong biofilm producers belonging to the genera Bacillus, Staphylococcus, Brevibacterium and Micrococcus. Pyocyanin inhibited biofilm activity in very minute concentrations. This was also confirmed by Scanning Electron Microscopy (SEM) and Confocal Laser Scanning Microscopy (CLSM). Both SEM and CLSM helped to visualize the biocontrol of biofilm formation by eight pathogens. The imaging and quantification by CLSM also established the impact of pyocyanin on biofilm-biocontrol mainly in the food industry.

The Impact of Dental Implant Surface Modifications on Osseointegration and Biofilm Formation

Journal of Clinical Medicine ◽

10.3390/jcm10081641 ◽

2021 ◽

Vol 10 (8) ◽

pp. 1641

Author(s):

Stefanie Kligman ◽

Zhi Ren ◽

Chun-Hsi Chung ◽

Michael Angelo Perillo ◽

Yu-Cheng Chang ◽

...

Keyword(s):

Dental Implant ◽

Biofilm Formation ◽

Bacterial Colonization ◽

Surface Modifications ◽

Implant Surface ◽

Oral Rehabilitation ◽

Surface Design ◽

Polyether Ether Ketone ◽

Dental Implant Surface ◽

The Impact

Implant surface design has evolved to meet oral rehabilitation challenges in both healthy and compromised bone. For example, to conquer the most common dental implant-related complications, peri-implantitis, and subsequent implant loss, implant surfaces have been modified to introduce desired properties to a dental implant and thus increase the implant success rate and expand their indications. Until now, a diversity of implant surface modifications, including different physical, chemical, and biological techniques, have been applied to a broad range of materials, such as titanium, zirconia, and polyether ether ketone, to achieve these goals. Ideal modifications enhance the interaction between the implant’s surface and its surrounding bone which will facilitate osseointegration while minimizing the bacterial colonization to reduce the risk of biofilm formation. This review article aims to comprehensively discuss currently available implant surface modifications commonly used in implantology in terms of their impact on osseointegration and biofilm formation, which is critical for clinicians to choose the most suitable materials to improve the success and survival of implantation.

Effect of Titanium Dioxide Nanoparticles on the Expression of Efflux Pump and Quorum-Sensing Genes in MDR Pseudomonas aeruginosa Isolates

Antibiotics ◽

10.3390/antibiotics10060625 ◽

2021 ◽

Vol 10 (6) ◽

pp. 625

Author(s):

Fatma Y. Ahmed ◽

Usama Farghaly Aly ◽

Rehab Mahmoud Abd El-Baky ◽

Nancy G. F. M. Waly

Keyword(s):

Titanium Dioxide ◽

Quorum Sensing ◽

Biofilm Formation ◽

Antimicrobial Agents ◽

Efflux Pump ◽

Titanium Dioxide Nanoparticles ◽

Sol Gel ◽

Efflux Pumps ◽

Antibiofilm Activity ◽

The Impact

Most of the infections caused by multi-drug resistant (MDR) P. aeruginosa strains are extremely difficult to be treated with conventional antibiotics. Biofilm formation and efflux pumps are recognized as the major antibiotic resistance mechanisms in MDR P. aeruginosa. Biofilm formation by P. aeruginosa depends mainly on the cell-to-cell communication quorum-sensing (QS) systems. Titanium dioxide nanoparticles (TDN) have been used as antimicrobial agents against several microorganisms but have not been reported as an anti-QS agent. This study aims to evaluate the impact of titanium dioxide nanoparticles (TDN) on QS and efflux pump genes expression in MDR P. aeruginosa isolates. The antimicrobial susceptibility of 25 P. aeruginosa isolates were performed by Kirby–Bauer disc diffusion. Titanium dioxide nanoparticles (TDN) were prepared by the sol gel method and characterized by different techniques (DLS, HR-TEM, XRD, and FTIR). The expression of efflux pumps in the MDR isolates was detected by the determination of MICs of different antibiotics in the presence and absence of carbonyl cyanide m-chlorophenylhydrazone (CCCP). Biofilm formation and the antibiofilm activity of TDN were determined using the tissue culture plate method. The effects of TDN on the expression of QS genes and efflux pump genes were tested using real-time polymerase chain reaction (RT-PCR). The average size of the TDNs was 64.77 nm. It was found that TDN showed a significant reduction in biofilm formation (96%) and represented superior antibacterial activity against P. aeruginosa strains in comparison to titanium dioxide powder. In addition, the use of TDN alone or in combination with antibiotics resulted in significant downregulation of the efflux pump genes (MexY, MexB, MexA) and QS-regulated genes (lasR, lasI, rhll, rhlR, pqsA, pqsR) in comparison to the untreated isolate. TDN can increase the therapeutic efficacy of traditional antibiotics by affecting efflux pump expression and quorum-sensing genes controlling biofilm production.

Management of Deep Spinal Wound Infections Following Instrumentation Surgery with Subfascial Negative Pressure Wound Therapy

Journal of Neurological Surgery Part A Central European Neurosurgery ◽

10.1055/s-0040-1720999 ◽

2021 ◽

Author(s):

Marcus Rickert ◽

Michael Rauschmann ◽

Nizar Latif-Richter ◽

Mohammad Arabmotlagh ◽

Tamin Rahim ◽

...

Keyword(s):

Risk Factors ◽

Wound Healing ◽

Wound Infection ◽

Spinal Fusion ◽

Negative Pressure Wound Therapy ◽

Wound Infections ◽

Wound Therapy ◽

Postoperative Wound ◽

Deep Wound ◽

The Impact

Abstract Background and Study Aims The treatment of infections following a spine surgery continues to be a challenge. Negative pressure wound therapy (NPWT) has been an effective method in the context of infection therapy, and its use has gained popularity in recent decades. This study aims to analyze the impact of known risk factors for postoperative wound infection on the efficiency and length of NPWT therapy until healing. Patients and Methods We analyzed 50 cases of NPWT treatment for deep wound infection after posterior and posteroanterior spinal fusion from March 2010 to July 2014 retrospectively. We included 32 women and 18 men with a mean age of 69 years (range, 36–87 years). Individual risk factors for postoperative infection, such as age, gender, obesity, diabetes, immunosuppression, duration of surgery, intraoperative blood loss, and previous surgeries, as well as type and onset (early vs. late) of the infection were analyzed. We assessed the associations between these risk factors and the number of revisions until wound healing. Results In 42 patients (84%), bacterial pathogens were successfully detected by means of intraoperative swabs and tissue samples during first revision. A total of 19 different pathogens could be identified with a preponderance of Staphylococcus epidermidis (21.4%) and S. aureus (19.0%). Methicillin-resistant S. aureus (MRSA) was recorded in two patients (2.6%). An average of four NPWT revisions was required until the infection was cured. Patients with infections caused by mixed pathogens required a significantly higher number of revisions (5.3 vs. 3.3; p < 0.01) until definitive wound healing. For the risk factors, no significant differences in the number of revisions could be demonstrated when compared with the patients without the respective risk factor. Conclusion NPWT was an effective therapy for the treatment of wound infections after spinal fusion. All patients in the study had their infections successfully cured, and all spinal implants could be retained. The number of revisions was similar to those reported in the published literature. The present study provides insights regarding the effectiveness of NPWT for the treatment of deep wound infection after spinal fusion. Further investigations on the impact of potential risk factors for postoperative wound healing disorders are required. Better knowledge on the impact of specific risk factors will contribute to a higher effectiveness of prophylaxis for postoperative wound infections considering the patient-specific situation.

Modulatory Effect of Glycated Collagen on Oral Streptococcal Nanoadhesion

Journal of Dental Research ◽

10.1177/0022034520946320 ◽

2020 ◽

Vol 100 (1) ◽

pp. 82-89

Author(s):

C.M.A.P. Schuh ◽

B. Benso ◽

P.A. Naulin ◽

N.P. Barrera ◽

L. Bozec ◽

...

Keyword(s):

Dental Caries ◽

Biofilm Formation ◽

Type I Collagen ◽

Type I ◽

Oral Streptococci ◽

Oral Diseases ◽

Collagen Crosslinking ◽

Initial Adhesion ◽

Collagen Glycation ◽

The Impact

Biofilm-mediated oral diseases such as dental caries and periodontal disease remain highly prevalent in populations worldwide. Biofilm formation initiates with the attachment of primary colonizers onto surfaces, and in the context of caries, the adhesion of oral streptococci to dentinal collagen is crucial for biofilm progression. It is known that dentinal collagen suffers from glucose-associated crosslinking as a function of aging or disease; however, the effect of collagen crosslinking on the early adhesion and subsequent biofilm formation of relevant oral streptococci remains unknown. Therefore, the aim of this work was to determine the impact of collagen glycation on the initial adhesion of primary colonizers such as Streptococcus mutans UA159 and Streptococcus sanguinis SK 36, as well as its effect on the early stages of streptococcal biofilm formation in vitro. Type I collagen matrices were crosslinked with either glucose or methylglyoxal. Atomic force microscopy nanocharacterization revealed morphologic and mechanical changes within the collagen matrix as a function of crosslinking, such as a significantly increased elastic modulus in crosslinked fibrils. Increased nanoadhesion forces were observed for S. mutans on crosslinked collagen surfaces as compared with the control, and retraction curves obtained for both streptococcal strains demonstrated nanoscale unbinding behavior consistent with bacterial adhesin-substrate coupling. Overall, glucose-crosslinked substrates specifically promoted the initial adhesion, biofilm formation, and insoluble extracellular polysaccharide production of S. mutans, while methylglyoxal treatment reduced biofilm formation for both strains. Changes in the adhesion behavior and biofilm formation of oral streptococci as a function of collagen glycation could help explain the biofilm dysbiosis seen in older people and patients with diabetes. Further studies are necessary to determine the influence of collagen crosslinking on the balance between acidogenic and nonacidogenic streptococci to aid in the development of novel preventive and therapeutic treatment against dental caries in these patients.

Antibiofilm and antivirulence potential of silver nanoparticles against multidrug-resistant Acinetobacter baumannii

Scientific Reports ◽

10.1038/s41598-021-90208-4 ◽

2021 ◽

Vol 11 (1) ◽

Author(s):

Helal F. Hetta ◽

Israa M. S. Al-Kadmy ◽

Saba Saadoon Khazaal ◽

Suhad Abbas ◽

Ahmed Suhail ◽

...

Keyword(s):

Silver Nanoparticles ◽

Antibacterial Activity ◽

Acinetobacter Baumannii ◽

Biofilm Formation ◽

Microtiter Plate ◽

Diffusion Method ◽

Resistance Pattern ◽

Infection Model ◽

The Impact

AbstractWe aimed to isolate Acinetobacter baumannii (A. baumannii) from wound infections, determine their resistance and virulence profile, and assess the impact of Silver nanoparticles (AgNPs) on the bacterial growth, virulence and biofilm-related gene expression. AgNPs were synthesized and characterized using TEM, XRD and FTIR spectroscopy. A. baumannii (n = 200) were isolated and identified. Resistance pattern was determined and virulence genes (afa/draBC, cnf1, cnf2, csgA, cvaC, fimH, fyuA, ibeA, iutA, kpsMT II, PAI, papC, PapG II, III, sfa/focDE and traT) were screened using PCR. Biofilm formation was evaluated using Microtiter plate method. Then, the antimicrobial activity of AgNPs was evaluated by the well-diffusion method, growth kinetics and MIC determination. Inhibition of biofilm formation and the ability to disperse biofilms in exposure to AgNPs were evaluated. The effect of AgNPs on the expression of virulence and biofilm-related genes (bap, OmpA, abaI, csuA/B, A1S_2091, A1S_1510, A1S_0690, A1S_0114) were estimated using QRT-PCR. In vitro infection model for analyzing the antibacterial activity of AgNPs was done using a co-culture infection model of A. baumannii with human fibroblast skin cell line HFF-1 or Vero cell lines. A. baumannii had high level of resistance to antibiotics. Most of the isolates harbored the fimH, afa/draBC, cnf1, csgA and cnf2, and the majority of A. baumannii produced strong biofilms. AgNPs inhibited the growth of A. baumannii efficiently with MIC ranging from 4 to 25 µg/ml. A. baumannii showed a reduced growth rate in the presence of AgNPs. The inhibitory activity and the anti-biofilm activity of AgNPs were more pronounced against the weak biofilm producers. Moreover, AgNPs decreased the expression of kpsMII , afa/draBC,bap, OmpA, and csuA/B genes. The in vitro infection model revealed a significant antibacterial activity of AgNPs against extracellular and intracellular A. baumannii. AgNPs highly interrupted bacterial multiplication and biofilm formation. AgNPs downregulated the transcription level of important virulence and biofilm-related genes. Our findings provide an additional step towards understanding the mechanisms by which sliver nanoparticles interfere with the microbial spread and persistence.

Host Peptidic Hormones Affecting Bacterial Biofilm Formation and Virulence

Journal of Innate Immunity ◽

10.1159/000493926 ◽

2018 ◽

Vol 11 (3) ◽

pp. 227-241 ◽

Cited By ~ 7

Author(s):

Olivier Lesouhaitier ◽

Thomas Clamens ◽

Thibaut Rosay ◽

Florie Desriac ◽

Mélissande Louis ◽

...

Keyword(s):

Biofilm Formation ◽

Bacterial Biofilm ◽

Critical Problem ◽

Resistant Variant ◽

Bacterial Physiology ◽

Gram Positive Bacteria ◽

Biofilm Production ◽

The Impact ◽

Original Approach ◽

Antibacterial Potential

Bacterial biofilms constitute a critical problem in hospitals, especially in resuscitation units or for immunocompromised patients, since bacteria embedded in their own matrix are not only protected against antibiotics but also develop resistant variant strains. In the last decade, an original approach to prevent biofilm formation has consisted of studying the antibacterial potential of host communication molecules. Thus, some of these compounds have been identified for their ability to modify the biofilm formation of both Gram-negative and Gram-positive bacteria. In addition to their effect on biofilm production, a detailed study of the mechanism of action of these human hormones on bacterial physiology has allowed the identification of new bacterial pathways involved in biofilm formation. In this review, we focus on the impact of neuropeptidic hormones on bacteria, address some future therapeutic issues, and provide a new view of inter-kingdom communication.

Antimicrobial and anti-biofilm potencies of dermcidin-derived peptide DCD-1L against Acinetobacter baumannii: an in vivo wound healing model

BMC Microbiology ◽

10.1186/s12866-022-02439-8 ◽

2022 ◽

Vol 22 (1) ◽

Author(s):

Zahra Farshadzadeh ◽

Maryam Pourhajibagher ◽

Behrouz Taheri ◽

Alireza Ekrami ◽

Mohammad Hossein Modarressi ◽

...

Keyword(s):

Wound Healing ◽

Acinetobacter Baumannii ◽

Biofilm Formation ◽

Histopathological Examination ◽

Inhibitory Effect ◽

Bacterial Attachment ◽

Burn Wound ◽

Conventional Antibiotics

Abstract Background The global emergence of Acinetobacter baumannii resistance to most conventional antibiotics presents a major therapeutic challenge and necessitates the discovery of new antibacterial agents. The purpose of this study was to investigate in vitro and in vivo anti-biofilm potency of dermcidin-1L (DCD-1L) against extensively drug-resistant (XDR)-, pandrug-resistant (PDR)-, and ATCC19606-A. baumannii. Methods After determination of minimum inhibitory concentration (MIC) of DCD-1L, in vitro anti-adhesive and anti-biofilm activities of DCD-1L were evaluated. Cytotoxicity, hemolytic activity, and the effect of DCD-1L treatment on the expression of various biofilm-associated genes were determined. The inhibitory effect of DCD-1L on biofilm formation in the model of catheter-associated infection, as well as, histopathological examination of the burn wound sites of mice treated with DCD-1L were assessed. Results The bacterial adhesion and biofilm formation in all A. baumannii isolates were inhibited at 2 × , 4 × , and 8 × MIC of DCD-1L, while only 8 × MIC of DCD-1L was able to destroy the pre-formed biofilm in vitro. Also, reduce the expression of genes involved in biofilm formation was observed following DCD-1L treatment. DCD-1L without cytotoxic and hemolytic activities significantly reduced the biofilm formation in the model of catheter-associated infection. In vivo results showed that the count of A. baumannii in infected wounds was significantly decreased and the promotion in wound healing by the acceleration of skin re-epithelialization in mice was observed following treatment with 8 × MIC of DCD-1L. Conclusions Results of this study demonstrated that DCD-1L can inhibit bacterial attachment and biofilm formation and prevent the onset of infection. Taking these properties together, DCD-1L appears as a promising candidate for antimicrobial and anti-biofilm drug development.

SP9.1.1 The Impact of Anaesthetic Use on Healing in Sub-cutaneous Abscess Management: A Retrospective Before and After Cohort Study

British Journal of Surgery ◽

10.1093/bjs/znab361.165 ◽

2021 ◽

Vol 108 (Supplement_7) ◽

Author(s):

Hannah Elkadi ◽

Eleanor Dodd ◽

Theodore Poulton ◽

William Bolton ◽

Joshua Burke ◽

...

Keyword(s):

Wound Healing ◽

Local Anaesthetic ◽

Surrogate Endpoints ◽

Incision And Drainage ◽

Number Of Patients ◽

Significant Difference ◽

Patient Reported ◽

Before And After ◽

The Impact

Abstract Aims Despite being the most common surgical procedure, there is wide variation that exists in the management of simple subcutaneous abscesses with no national guideline describing best practice. During the COVID-19 Pandemic national guidelines promoted the use of regional or local anaesthetic (LA) instead of general anaesthesia (GA) to avoid aerosol generating intubation associated with GA. This study aimed to assess the impact of anaesthetic choice in outcomes following incision and drainage of subcutaneous abscesses. Methods Two cohorts of patients undergoing abscess incision and drainage at St. James’ University Hospital Leeds were retrospectively identified over a 14-week period before and after the introduction of the new COVID-19 anaesthetic guidelines. Wound healing surrogate endpoints were used: i) total number of follow up appointments and ii) attendance to healthcare services after 30 days from I&D. Result 133 patients were included. Significantly more procedures were performed under LA after the intervention (84.1% vs 5.7%; p < 0.0001) with a significant reduction in wound packing (68.3% vs 87.1%. p=0.00473). Follow up data found no significant difference in the average number of follow-up appointments (7.46 vs 5.11; p = 0.0731) and the number of patients who required ongoing treatment after 30 days (n = 14 vs n = 14, p = 0.921). Conclusion Drainage of simple subcutaneous abscess under 5 cm is safe under local anaesthetic with no significant difference in surrogate endpoints of wound healing observed in this patient cohort. Recurrent packing may not be required. Future work should explore patient reported measures such as pain management and the health economics of this intervention.