In vitro Inhibition of Biofilm Formation on Silicon Rubber Voice Prosthesis: Α Systematic Review and Meta-Analysis

Introduction: Biofilm formation on voice prostheses is the primary reason for their premature implant dysfunction. Multiple strategies have been proposed over the last decades to achieve inhibition of biofilm formation on these devices. The purpose of this study was to assess the results of the available in vitro biofilm inhibition modalities on silicone rubber voice prostheses. Methods: We conducted a systematic search in PubMed, Embase, and the Cochrane Central Register of Controlled Trials databases up to February 29, 2020. A total of 33 in vitro laboratory studies investigating the efficacy of different coating methods against Candida, Staphylococcus, Streptococcus, Lactobacilli, and Rothia biofilm growth on silicone rubber medical devices were included. Subgroup analysis linked to the type of prevention modality was carried out, and quality assessment was performed with the use of the modified CONSORT tool. Results: Data from 33 studies were included in qualitative analysis, of which 12 qualified for quantitative analysis. For yeast biofilm formation assessment, there was a statistically significant difference in favor of the intervention group (standardized mean difference [SMD] = −1.20; 95% confidence interval [CI] [−1.73, −0.66]; p < 0.0001). Subgroup analysis showed that combined methods (active and passive surface modification) are the most effective for biofilm inhibition in yeast (SMD = −2.53; 95% CI [−4.02, −1.03]; p = 0.00001). No statistically significant differences between intervention and control groups were shown for bacterial biofilm inhibition (SMD = −0.09; 95% CI [−0.68, 0.46]; p = 0.65), and the results from the subgroup analysis found no notable differences between the surface modification methods. After analyzing data on polymicrobial biofilms, a statistically significant difference in favor of prevention methods in comparison with the control group was detected (SMD = −2.59; 95% CI [−7.48, 2.31]; p = 0.30). Conclusions: The meta-analysis on biofilm inhibition demonstrated significant differences in favor of yeast biofilm inhibition compared to bacteria. A stronger inhibition with the application of passive or combined active and passive surface modification techniques was reported.

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Materials Sealing Preventing Biofilm Formation in Implant/Abutment Joints: Which Is the Most Effective? A Systematic Review and Meta-Analysis

Journal of Oral Implantology ◽

10.1563/aaid-joi-d-19-00121 ◽

2020 ◽

Vol 46 (2) ◽

pp. 163-171

Author(s):

Cecília Alves de Sousa ◽

Maria Beatriz Bello Taborda ◽

Gustavo Antônio Correa Momesso ◽

Eduardo Passos Rocha ◽

Paulo Henrique dos Santos ◽

...

Keyword(s):

Systematic Review ◽

Biofilm Formation ◽

Meta Analysis ◽

Significance Level ◽

Gutta Percha ◽

Significant Difference ◽

Physical Barriers ◽

External Connection

The purpose of this systematic review was to evaluate the literature available for materials exhibiting the best efficacy in preventing biofilm formation in the interior of implants. We searched PubMed/MEDLINE, Scopus, and Cochrane databases. This review is registered with the PROSPERO database and followed the suitability of the PRISMA protocol. The initial search resulted in 326 articles from the databases. After they were read, 8 articles remained, and the inclusion and exclusion criteria were applied. Six of these 8 articles were classified as in vitro and 2 were classified as in situ. The regions of the implants evaluated ranged from the interface of the pieces to the occlusal upper access of the abutment. The implant connections evaluated the Morse taper, external connection, and internal connection. Meta-analysis of the quantitative data was performed at a significance level of .05. Cotton exhibited poor control of infiltration, even in combination with other materials. Isolated gutta-percha (GP) and polytetrafluoroethylene (PTFE) tape with composite resin (CR) or GP performed better as physical barriers. The best results for chemical barriers were observed by the application of 1% chlorhexidine gluconate (CG) gel, thymol varnish, and the deposition of Ag films onto the surface. The applied meta-analysis did not show a significant difference in comparison between the different types of implant connections (P > .05). The application of CG and thymol varnish antimicrobials was effective in preventing biofilm formation and easy clinical execution; these could be used in combination with CR, GP, and PTFE.

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Effects of vancomycin, daptomycin, and tigecycline on coagulase-negative staphylococcus biofilm and bacterial viability within biofilm: an in vitro biofilm model

Canadian Journal of Microbiology ◽

10.1139/cjm-2015-0855 ◽

2016 ◽

Vol 62 (9) ◽

pp. 735-743 ◽

Cited By ~ 5

Author(s):

Barcin Ozturk ◽

Necati Gunay ◽

Bulent M. Ertugrul ◽

Serhan Sakarya

Keyword(s):

Biofilm Formation ◽

Treatment Time ◽

Antimicrobial Effect ◽

Bacterial Biofilm ◽

Coagulase Negative Staphylococcus ◽

Biofilm Inhibition ◽

Major Barrier ◽

Biofilm Model ◽

Repeated Doses

Bacteria may hide in a hydrated polysaccharide matrix known as a biofilm. The structure of the bacterial biofilm renders phagocytosis difficult and increases antibiotic resistance. We hypothesized that repeated doses of antibiotics have an effect on bacteria within the biofilm and that it could inhibit or eradicate biofilm formation. Two clinical biofilm-positive coagulase-negative staphylococcus isolates were evaluated. The effects of antibiotics on preformed and nascent biofilm and on bacterial eradication within the biofilm were determined using different doses of vancomycin, daptomycin, and tigecycline for different durations in an in vitro biofilm model. Vancomycin neither penetrated the biofilm nor had any microbicidal effect on bacteria within the biofilm. Daptomycin had a microbicidal effect on bacteria within the biofilm but had no effect on biofilm inhibition and eradication (independent from dose and treatment time). Tigecycline inhibited and eradicated biofilm formation and had a microbicidal effect on bacteria within the biofilm. In conclusion, (i) biofilm formation appeared to be a major barrier to vancomycin activity, (ii) daptomycin had an antimicrobial effect on the bacteria within the biofilm but not on the biofilm burden, and (iii) tigecycline had effects both on bacteria within the biofilm and on biofilm burden. Thus, both tigecycline and daptomycin might be promising candidates for the treatment of biofilm infections.

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Antibiotics Application Strategies to Control Biofilm Formation in Pathogenic Bacteria

Current Pharmaceutical Biotechnology ◽

10.2174/1389201020666191112155905 ◽

2020 ◽

Vol 21 (4) ◽

pp. 270-286 ◽

Cited By ~ 2

Author(s):

Fazlurrahman Khan ◽

Dung T.N. Pham ◽

Sandra F. Oloketuyi ◽

Young-Mog Kim

Keyword(s):

Biofilm Formation ◽

Pathogenic Bacteria ◽

Extracellular Polymeric Substances ◽

Quorum Quenching ◽

Resistance Mechanisms ◽

Bacterial Biofilm ◽

Bacterial Cells ◽

High Concentration ◽

Biofilm Inhibition ◽

Abiotic Surfaces

Background: The establishment of a biofilm by most pathogenic bacteria has been known as one of the resistance mechanisms against antibiotics. A biofilm is a structural component where the bacterial community adheres to the biotic or abiotic surfaces by the help of Extracellular Polymeric Substances (EPS) produced by bacterial cells. The biofilm matrix possesses the ability to resist several adverse environmental factors, including the effect of antibiotics. Therefore, the resistance of bacterial biofilm-forming cells could be increased up to 1000 times than the planktonic cells, hence requiring a significantly high concentration of antibiotics for treatment. Methods: Up to the present, several methodologies employing antibiotics as an anti-biofilm, antivirulence or quorum quenching agent have been developed for biofilm inhibition and eradication of a pre-formed mature biofilm. Results: Among the anti-biofilm strategies being tested, the sub-minimal inhibitory concentration of several antibiotics either alone or in combination has been shown to inhibit biofilm formation and down-regulate the production of virulence factors. The combinatorial strategies include (1) combination of multiple antibiotics, (2) combination of antibiotics with non-antibiotic agents and (3) loading of antibiotics onto a carrier. Conclusion: The present review paper describes the role of several antibiotics as biofilm inhibitors and also the alternative strategies adopted for applications in eradicating and inhibiting the formation of biofilm by pathogenic bacteria.

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The high risk of malarial recurrence in patients with Plasmodium-mixed infection after treatment with antimalarial drugs: a systematic review and meta-analysis

Parasites & Vectors ◽

10.1186/s13071-021-04792-5 ◽

2021 ◽

Vol 14 (1) ◽

Author(s):

Aongart Mahittikorn ◽

Frederick Ramirez Masangkay ◽

Kwuntida Uthaisar Kotepui ◽

Giovanni De Jesus Milanez ◽

Manas Kotepui

Keyword(s):

Systematic Review ◽

Mixed Infection ◽

Subgroup Analysis ◽

Initial Treatment ◽

Meta Analysis ◽

Antimalarial Drugs ◽

Secondary Outcome ◽

Significant Heterogeneity ◽

Pooled Prevalence ◽

Significant Difference

Abstract Background Malaria mixed infections are often unrecognized by microscopists in the hospitals, and a delay or failure to treat Plasmodium-mixed infection may lead to aggravated morbidity and increased mortality. The present study aimed to quantify the pooled proportion and risk of malarial recurrences after the treatment of Plasmodium-mixed infection. The results of the study may provide benefits in the management of Plasmodium-mixed infection in co-endemic regions. Methods This systematic review and meta-analysis searched the international Prospective Register of Systematic Reviews (PROSPERO; ID = CRD42020199709), MEDLINE, Web of Science, and Scopus for potentially relevant studies in any language published between January 1, 1936, and July 20, 2020, assessing drug efficacy in patients with Plasmodium-mixed infection. The primary outcome was the pooled prevalence of Plasmodium parasitemia after initiating antimalarial treatment for Plasmodium-mixed infection. The secondary outcome was the pooled risk ratio (RR) of malarial recurrence in Plasmodium-mixed infection compared with those in Plasmodium falciparum and Plasmodium vivax mono-infection. The pooled analyses were calculated by random-effects meta-analysis. After the initial treatment in different days of recurrences (≤ 28 days or > 28 days), the risk of Plasmodium parasitemia was compared in subgroup analysis. Results Out of 5217 screened studies, 11 were included in the meta-analysis, including 4390 patients from six countries. The pooled prevalence of all recurrences of Plasmodium-mixed parasitemia was 30% (95% confidence interval (CI) 16–43; I2: 99.2%; 11 studies). The RR of malarial recurrence within 28 days after the initial treatment (clinical treatment failure) of Plasmodium-mixed parasitemia compared with the treatment of P. falciparum was 1.22 (p: 0.029; 95% CI 1.02–1.47; Cochran Q: 0.93; I2: 0%; six studies), while there was no significant difference in the risk of recurrence 28 days after initial treatment compared with the treatment of P. falciparum (p: 0.696, RR: 1.14; 95% CI 0.59–2.18; Cochran Q < 0.05; I2: 98.2%; four studies). The subgroup analysis of antimalarial drugs showed that significant malarial recurrence within 28 days was observed in patients treated with artemisinin-based combination therapies (ACTs) with no significant heterogeneity (p: 0.028, RR: 1.31; 95% CI 1.03–1.66; Cochran Q: 0.834; I2: 0%). Conclusions The present findings showed a high prevalence of malarial recurrence after the initial treatment of Plasmodium-mixed infection. Moreover, significant malaria recurrence of mixed infection occurred within 28 days after treatment with ACTs. Graphic Abstract

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Diagnostic Value of Telomerase Activity in Patients With Bladder Cancer: A Meta-Analysis of Diagnostic Test

Frontiers in Oncology ◽

10.3389/fonc.2020.570127 ◽

2020 ◽

Vol 10 ◽

Author(s):

Lei Peng ◽

Jinze Li ◽

Chunyang Meng ◽

Jinming Li ◽

Dandan Tang ◽

...

Keyword(s):

Bladder Cancer ◽

Subgroup Analysis ◽

Meta Analysis ◽

Negative Likelihood Ratio ◽

High Specificity ◽

Diagnostic Value ◽

Telomerase Activity ◽

Low Grade ◽

Potential Biomarker ◽

Significant Difference

BackgroundThis study aimed to evaluate the diagnostic value of telomerase activity (TA) for bladder cancer (BC) by meta-analysis.MethodsWe conducted a systematic search of studies published on PubMed, Embase, and Web of Science up to June 1, 2019. We used Stata 15 and Review Manager 5.3 for calculations and statistical analysis.ResultsTo evaluate the diagnostic value of TA for BC, we performed a meta-analysis on 22 studies, with a total of 2,867 individuals, including sensitivity, specificity, positive and negative likelihood ratio (PLR, NLR), diagnostic odds ratio (DOR), and 95% confidence intervals (CIs). The pooled parameters were calculated from all studies, and we found a sensitivity of 0.79 (95% CI: 0.72–0.84), a specificity of 0.91 (95% CI: 0.87–0.94), a PLR of 8.91 (95% CI: 5.91–13.43), an NLR of 0.24 (95% CI: 0.15–0.37), a DOR of 37.90 (95% CI: 23.32–61.59), and an AUC of 0.92 (95% CI: 0.90–0.94). We also conducted a subgroup analysis based on the different stages and grades of BC. Results from the subgroup analysis showed that there was no significant difference in TA in either high and low stages of BC, but that low-grade tumors had a lower TA than high-grade tumours.ConclusionsTA can be used as a potential biomarker for the diagnosis of bladder cancer with its high specificity. Rigorous and high-quality prospective studies are required to verify our conclusion.

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Biofilm reduction potential of 0.02% polyhexanide irrigation solution in several types of urethral catheters

BMC Urology ◽

10.1186/s12894-021-00826-3 ◽

2021 ◽

Vol 21 (1) ◽

Author(s):

Florian H. H. Brill ◽

Julia Hambach ◽

Christian Utpatel ◽

Diana C. Mogrovejo ◽

Henrik Gabriel ◽

...

Keyword(s):

Membrane Filtration ◽

Saline Solution ◽

Bacterial Biofilm ◽

Plate Count ◽

Vitro Assay ◽

Significant Difference ◽

Irrigation Solution ◽

Clinically Relevant Bacteria

Abstract Background Long-term use of urethral catheters is associated with high risk of urinary tract infection (UTI) and blockage. Microbial biofilms are a common cause of catheter blockage, reducing their lifetime and significantly increasing morbidity of UTIs. A 0.02% polyhexanide irrigation solution developed for routine mechanical rinsing shows potential for bacterial decolonization of urethral catheters and has the potential to reduce or prevent biofilm formation. Methods Using an in vitro assay with standard market-leading types of catheters artificially contaminated with clinically relevant bacteria, assays were carried out to evaluate the biofilm reduction and prevention potential of a 0.02% polyhexanide solution versus no intervention (standard approach) and irrigation with saline solution (NaCl 0.9%). The efficiency of decolonization was measured through microbial plate count and membrane filtration. Results Irrigation using a 0.02% polyhexanide solution is suitable for the decolonization of a variety of transurethral catheters. The effect observed is significant compared to irrigation with 0.9% saline solution (p = 0.002) or no treatment (p = 0.011). No significant difference was found between irrigation with 0.9% saline solution and no treatment (p = 0.74). Conclusions A 0.02% polyhexanide solution is able to reduce bacterial biofilm from catheters artificially contaminated with clinically relevant bacteria in vitro. The data shows a reduction of the viability of thick bacterial biofilms in a variety of commercially available urinary catheters made from silicone, latex-free silicone, hydrogel-coated silicone and PVC. Further research is required to evaluate the long-term tolerability and efficacy of polyhexanide in clinical practice.

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Dose dependence of efficacy but not of safety in sublingual immunotherapy

Monaldi Archives for Chest Disease ◽

10.4081/monaldi.2006.584 ◽

2016 ◽

Vol 65 (1) ◽

Author(s):

F. Frati ◽

C. Incorvaia ◽

F. Marcucci ◽

L. Sensi ◽

G. Di Cara ◽

...

Keyword(s):

Sublingual Immunotherapy ◽

Clinical Symptoms ◽

Meta Analysis ◽

Dose Dependence ◽

Subcutaneous Immunotherapy ◽

High Dose ◽

Systemic Reactions ◽

Significant Difference

Sublingual immunotherapy (SLIT) currently represents, as indicated by meta-analysis of its efficacy and safety, a valid option to the generally used traditional subcutaneous immunotherapy (SCIT) for treating respiratory allergy. Regarding efficacy, recent studies demonstrated that, similar to what has already been observed in SCIT as well as in experimental and clinical studies about the magnitudo of allergen exposure, the effectiveness on both clinical symptoms and immunologic changes depends on the amount of allergen administered during treatment. In addition, in vitro studies addressed with the role of dendritic cells, currently considered to be of pivotal importance in orienting toward tolerance the immune response to allergens, showed that the internalisation of allergen molecules, which is followed by tolerogenic presentation to T cells, depends on the amount of allergen. However, such dose dependence is not apparent concerning the safety. In fact, the comparison of studies respectively conducted with high and low allergen doses did not show differences in the rate of systemic reactions, which in any case never had the presentation of anaphylaxis, and instead a significant difference in the rate of local reactions, following the oral and gastrointestinal contact with the allergen extract, in favour of high dose studies.

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A Single B-Repeat of Staphylococcus epidermidis Accumulation-Associated Protein Induces Protective Immune Responses in an Experimental Biomaterial-Associated Infection Mouse Model

Clinical and Vaccine Immunology ◽

10.1128/cvi.00306-14 ◽

2014 ◽

Vol 21 (9) ◽

pp. 1206-1214 ◽

Cited By ~ 12

Author(s):

Lin Yan ◽

Lei Zhang ◽

Hongyan Ma ◽

David Chiu ◽

James D. Bryers

Keyword(s):

Staphylococcus Epidermidis ◽

Biofilm Formation ◽

Porous Scaffold ◽

The United States ◽

Protein Vaccine ◽

Weight Changes ◽

Biofilm Inhibition ◽

Content Type ◽

Accumulation Associated Protein

ABSTRACTNosocomial infections are the fourth leading cause of morbidity and mortality in the United States, resulting in 2 million infections and ∼100,000 deaths each year. More than 60% of these infections are associated with some type of biomedical device.Staphylococcus epidermidisis a commensal bacterium of the human skin and is the most common nosocomial pathogen infecting implanted medical devices, especially those in the cardiovasculature.S. epidermidisantibiotic resistance and biofilm formation on inert surfaces make these infections hard to treat. Accumulation-associated protein (Aap), a cell wall-anchored protein ofS. epidermidis, is considered one of the most important proteins involved in the formation ofS. epidermidisbiofilm. A small recombinant protein vaccine comprising a single B-repeat domain (Brpt1.0) ofS. epidermidisRP62A Aap was developed, and the vaccine's efficacy was evaluatedin vitrowith a biofilm inhibition assay andin vivoin a murine model of biomaterial-associated infection. A high IgG antibody response againstS. epidermidisRP62A was detected in the sera of the mice after two subcutaneous immunizations with Brpt1.0 coadministered with Freund's adjuvant. Sera from Brpt1.0-immunized mice inhibitedin vitroS. epidermidisRP62A biofilm formation in a dose-dependent pattern. After receiving two immunizations, each mouse was surgically implanted with a porous scaffold disk containing 5 × 106CFU ofS. epidermidisRP62A. Weight changes, inflammatory markers, and histological assay results after challenge withS. epidermidisindicated that the mice immunized with Brpt1.0 exhibited significantly higher resistance toS. epidermidisRP62A implant infection than the control mice. Day 8 postchallenge, there was a significantly lower number of bacteria in scaffold sections and surrounding tissues and a lower residual inflammatory response to the infected scaffold disks for the Brpt1.0-immunized mice than for of the ovalbumin (Ova)-immunized mice.

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Clindamycin-loaded titanium prevents implant-related infection through blocking biofilm formation

Journal of Biomaterials Applications ◽

10.1177/08853282211051183 ◽

2021 ◽

pp. 088532822110511

Author(s):

Youbin Li ◽

Shaochuan Wang ◽

Shidan Li ◽

Jun Fei

Keyword(s):

Surface Modification ◽

Rat Model ◽

Biofilm Formation ◽

High Performance ◽

Bacterial Colonization ◽

Tissue Homogenate ◽

Tartrate Resistant Acid Phosphatase ◽

Layer By Layer

Implant-related infection is a disastrous complication. Surface modification of titanium is considered as an important strategy to prevent implant-related infection. However, there is no recognized surface modification strategy that can be applied in clinic so far. We explored a new strategy of coating. The clindamycin-loaded titanium was constructed by layer-by-layer self-assembly. The release of clindamycin from titanium was detected through high performance liquid chromatography. Different titanium was co-cultured with Staphylococcus aureus for 24 h in vitro, then the effect of different titanium on bacterial colonization and biofilm formation was determined by spread plate method and scanning electron microscopy. Cytotoxicity and cytocompatibility of clindamycin-loaded titanium on MC3T3-E1 cells were measured by CCK8. The antibacterial ability of clindamycin-loaded titanium in vivo was also evaluated using a rat model of osteomyelitis. The number of osteoclasts in bone defect was observed by tartrate-resistant acid phosphatase staining. Bacterial burden of surrounding tissues around the site of infection was calculated by tissue homogenate and colony count. Clindamycin-loaded titanium could release clindamycin slowly within 160 h. It reduced bacterial colonization by three orders of magnitude compare to control ( p < .05) and inhibits biofilm formation in vitro. Cells proliferation and adhesion were similar on three titanium surfaces ( p > .05). In vivo, clindamycin-loaded titanium improved bone healing, reduced microbial burden, and decreased the number of osteoclasts compared control titanium in the rat model of osteomyelitis. This study demonstrated that clindamycin-loaded titanium exhibited good biocompatibility, and showed antibacterial activity both in vivo and in vitro. It is promising and might have potential for clinical application.

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Alternative Tendon Coaptations to the Pulvertaft Weave Technique: A Systematic Review and Meta-Analysis of Biomechanical Studies

Hand ◽

10.1177/15589447211043213 ◽

2021 ◽

pp. 155894472110432

Author(s):

Emily M. Graham ◽

Jeremie D. Oliver ◽

Russell Hendrycks ◽

Dino Maglic ◽

Shaun D. Mendenhall

Keyword(s):

Systematic Review ◽

Yield Strength ◽

Random Effects ◽

Meta Analysis ◽

Dichotomous Data ◽

Inverse Variance ◽

Significant Difference ◽

Alternative Techniques ◽

Meta Analyses

Background The Pulvertaft weave technique (PT) is frequently used during tendon repairs and transfers. However, this technique is associated with limitations. In this systematic review and meta-analysis, quantitative and qualitative analyses were performed on in vitro, biomechanical studies that compared the PT with alternative techniques. Methods Articles included for qualitative and/or qualitative analysis were identified following Preferred Reporting Items for Systematic Reviews and Meta-Analyses guidelines. Studies included in the meta-analysis were analyzed either as continuous data with inverse variance and random effects or as dichotomous data using a Mantel-Haenszel analysis assuming random effects to calculate an odds ratio. Results A comprehensive electronic search yielded 8 studies meeting inclusion criteria for meta-analysis. Two studies with a total of 65 tendon coaptations demonstrated no significant difference in strength between the PT and traditional side-to-side (STS) techniques ( P = .92). Two studies with a total of 43 tendon coaptations showed that the STS with 1 weave has a higher yield strength than the PT ( P = .03). Two studies with a total of 62 tendon repairs demonstrated no significant difference in strength between the PT and the step-cut (SC) techniques ( P = .70). The final 2 studies included 46 tendon repairs and demonstrated that the wrap around (WA) technique has a higher yield strength than the PT ( P < .001). Conclusions The STS, SC, and WA techniques are preferred for improving tendon form. The STS and WA techniques have superior yield strengths than the PT, and the SC technique withstands similar stress to failure as the PT.

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