scholarly journals Biofilm Formation of Clinical Klebsiella pneumoniae Strains Isolated from Tracheostomy Tubes and Their Association with Antimicrobial Resistance, Virulence and Genetic Diversity

Pathogens ◽  
2021 ◽  
Vol 10 (10) ◽  
pp. 1345
Author(s):  
Dorota Ochońska ◽  
Łukasz Ścibik ◽  
Monika Brzychczy-Włoch
Keyword(s):  
Genetic Diversity ◽  
Bacterial Adhesion ◽  
Biofilm Formation ◽  
Large Range ◽  
Bacterial Colonization ◽  
Genes Encoding ◽  
Invasive Infections ◽  
Tracheostomy Tubes ◽  
Range Of Variation

(1) Background: Due to the commonness of tracheotomy procedures and the wide use of biomaterials in the form of tracheostomy tubes (TTs), the problem of biomaterial-associated infections (BAIs) is growing. Bacterial colonization of TTs results in the development of biofilms on the surface of biomaterials, which may contribute to the development of invasive infections in tracheostomized patients. (2) Methods: Clinical strains of K. pneumoniae, isolated from TTs, were characterized according to their ability to form biofilms, as well as their resistance to antibiotics, whether they harbored ESβL genes, the presence of selected virulence factors and genetic diversity. (3) Results: From 53 patients, K. pneumoniae were detected in 18 of the TTs examined, which constitued 34% of all analyzed biomaterials. Three of the strains (11%) were ESβL producers and all had genes encoding CTX-M-1, SHV and TEM enzymes. 44.4% of isolates were biofilm formers, SEM demonstrating that K. pneumoniae formed differential biofilms on the surface of polyethylene (PE) and polyvinyl chloride (PVC) TTs in vitro. A large range of variation in the share of fimbrial genes was observed. PFGE revealed sixteen genetically distinct profiles. (4) Conclusions: Proven susceptibility of TT biomaterials to colonization by K. pneumoniae means that the attention of research groups should be focused on achieving a better understanding of the bacterial pathogens that form biofilms on the surfaces of TTs. In addition, research efforts should be directed at the development of new biomaterials or the modification of existing materials, in order to prevent bacterial adhesion to their surfaces.

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

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.

scholarly journals A microfluidic platform for in situ investigation of biofilm formation and its treatment under controlled conditions

2020 ◽  
Vol 18 (1) ◽  
Author(s):  
Hervé Straub ◽  
Leo Eberl ◽  
Manfred Zinn ◽  
René M. Rossi ◽  
Katharina Maniura-Weber ◽  
...  
Keyword(s):  
Single Cell ◽  
Real Time ◽  
Bacterial Adhesion ◽  
Biofilm Formation ◽  
Bacterial Colonization ◽  
Rich Medium ◽  
Flow Conditions ◽  
Microfluidic Platform ◽  
Adhesion Rate

Abstract Background Studying bacterial adhesion and early biofilm development is crucial for understanding the physiology of sessile bacteria and forms the basis for the development of novel antimicrobial biomaterials. Microfluidics technologies can be applied in such studies since they permit dynamic real-time analysis and a more precise control of relevant parameters compared to traditional static and flow chamber assays. In this work, we aimed to establish a microfluidic platform that permits real-time observation of bacterial adhesion and biofilm formation under precisely controlled homogeneous laminar flow conditions. Results Using Escherichia coli as the model bacterial strain, a microfluidic platform was developed to overcome several limitations of conventional microfluidics such as the lack of spatial control over bacterial colonization and allow label-free observation of bacterial proliferation at single-cell resolution. This platform was applied to demonstrate the influence of culture media on bacterial colonization and the consequent eradication of sessile bacteria by antibiotic. As expected, the nutrient-poor medium (modified M9 minimal medium) was found to promote bacterial adhesion and to enable a higher adhesion rate compared to the nutrient-rich medium (tryptic soy broth rich medium ). However, in rich medium the adhered cells colonized the glass surface faster than those in poor medium under otherwise identical conditions. For the first time, this effect was demonstrated to be caused by a higher retention of newly generated bacteria in the rich medium, rather than faster growth especially during the initial adhesion phase. These results also indicate that higher adhesion rate does not necessarily lead to faster biofilm formation. Antibiotic treatment of sessile bacteria with colistin was further monitored by fluorescence microscopy at single-cell resolution, allowing in situ analysis of killing efficacy of antimicrobials. Conclusion The platform established here represents a powerful and versatile tool for studying environmental effects such as medium composition on bacterial adhesion and biofilm formation. Our microfluidic setup shows great potential for the in vitro assessment of new antimicrobials and antifouling agents under flow conditions.

scholarly journals Expression of biofilm-associated genes of Streptococcus mutans in response to glucose and sucrose

2007 ◽  
Vol 56 (11) ◽  
pp. 1528-1535 ◽  
Author(s):  
Moshe Shemesh ◽  
Avshalom Tam ◽  
Doron Steinberg
Keyword(s):  
Gene Expression ◽  
Streptococcus Mutans ◽  
Biofilm Formation ◽  
Fold Increase ◽  
Extracellular Polysaccharide ◽  
Tooth Surface ◽  
Differential Analysis ◽  
Nutrient Contents ◽  
Genes Encoding

Streptococcus mutans is known as a primary pathogen of dental caries, one of the most common human infectious diseases. Exopolysaccharide synthesis, adherence to tooth surface and biofilm formation are important physiological and virulence factors of S. mutans. In vitro comparative gene expression analysis was carried out to differentiate 10 selected genes known to be mostly involved in S. mutans biofilm formation by comparing the expression under biofilm and planktonic environments. Real-time RT-PCR analyses indicated that all of the genes tested were upregulated in the biofilm compared to cells grown in planktonic conditions. The influence of simple dietary carbohydrates on gene expression in S. mutans biofilm was tested also. Among the tested genes, in the biofilm phase, the greatest induction was observed for gtf and ftf, which are genes encoding the extracellular polysaccharide-producing enzymes. Biofilm formation was accompanied by a 22-fold induction in the abundance of mRNA encoding glucosyltransferase B (GTFB) and a 14.8 -fold increase in mRNA encoding GTFC. Levels of mRNA encoding fructosyltransferase were induced approximately 11.8-fold in biofilm-derived cells. Another notable finding of this study suggests that glucose affects the expression of S. mutans GS5 biofilm genes. In spite of a significant upregulation in biofilm-associated gene expression in the presence of sucrose, the presence of glucose with sucrose reduced expression of most tested genes. Differential analysis of the transcripts from S. mutans, grown in media with various nutrient contents, revealed significant shifts in the expression of the genes involved in biofilm formation. The results presented here provide new insights at the molecular level regarding gene expression in this bacterium when grown under biofilm conditions, allowing a better understanding of the mechanism of biofilm formation by S. mutans.

scholarly journals The Sodium-Driven Flagellar Motor Controls Exopolysaccharide Expression in Vibrio cholerae

2004 ◽  
Vol 186 (15) ◽  
pp. 4864-4874 ◽  
Author(s):  
Crystal M. Lauriano ◽  
Chandradipa Ghosh ◽  
Nidia E. Correa ◽  
Karl E. Klose
Keyword(s):  
Vibrio Cholerae ◽  
Gene Transcription ◽  
Biofilm Formation ◽  
Diarrheal Disease ◽  
Response Regulator ◽  
Gene Clusters ◽  
Signaling Cascade ◽  
Genes Encoding ◽  
Life Threatening

ABSTRACT Vibrio cholerae causes the life-threatening diarrheal disease cholera. This organism persists in aquatic environments in areas of endemicity, and it is believed that the ability of the bacteria to form biofilms in the environment contributes to their persistence. Expression of an exopolysaccharide (EPS), encoded by two vps gene clusters, is essential for biofilm formation and causes a rugose colonial phenotype. We previously reported that the lack of a flagellum induces V. cholerae EPS expression. To uncover the signaling pathway that links the lack of a flagellum to EPS expression, we introduced into a rugose flaA strain second-site mutations that would cause reversion back to the smooth phenotype. Interestingly, mutation of the genes encoding the sodium-driven motor (mot) in a nonflagellated strain reduces EPS expression, biofilm formation, and vps gene transcription, as does the addition of phenamil, which specifically inhibits the sodium-driven motor. Mutation of vpsR, which encodes a response regulator, also reduces EPS expression, biofilm formation, and vps gene transcription in nonflagellated cells. Complementation of a vpsR strain with a constitutive vpsR allele likely to mimic the phosphorylated state (D59E) restores EPS expression and biofilm formation, while complementation with an allele predicted to remain unphosphorylated (D59A) does not. Our results demonstrate the involvement of the sodium-driven motor and suggest the involvement of phospho-VpsR in the signaling cascade that induces EPS expression. A nonflagellated strain expressing EPS is defective for intestinal colonization in the suckling mouse model of cholera and expresses reduced amounts of cholera toxin and toxin-coregulated pili in vitro. Wild-type levels of virulence factor expression and colonization could be restored by a second mutation within the vps gene cluster that eliminated EPS biosynthesis. These results demonstrate a complex relationship between the flagellum-dependent EPS signaling cascade and virulence.

An In Vitro and In Vivo Study on the Intensity of Adhesion and Colonization by Staphylococcus epidermidis and Pseudomonas aeruginosa on Originally Synthesized Biomaterials With Different Chemical Composition and Modified Surfaces and Their Effect on Expression of TNF-α, β-Defensin 2 and IL-10 in Tissues

Medicina ◽  
2011 ◽  
Vol 47 (10) ◽  
pp. 80 ◽  
Author(s):  
Aigars Reinis ◽  
Māra Pilmane ◽  
Agnese Stunda ◽  
Jānis Vētra ◽  
Juta Kroiča ◽  
...  
Keyword(s):  
Bacterial Adhesion ◽  
Bacterial Colonization ◽  
Cell Activity ◽  
In Vivo Study ◽  
Plate Count ◽  
Nonspecific Resistance ◽  
Colony Forming Units ◽  
Tnf Α

The aim of this study was to determine adhesion and colonization of bacteria on the surface of originally synthesized glass-ceramic biomaterials and their effect on inflammation reactions in tissues surrounding the implant. Materials and Methods. Biomaterial discs were contaminated with bacterial suspensions of 10, 102, and 103 colony forming units (CFU)/mL (P. aeruginosa ATCC 27853 and S. epidermidis ATCC 12228), and after 2 hours of cultivation, the intensity of bacterial adhesion was determined. For in vivo tests, the samples were contaminated with 102 and 103 CFU/mL cultivated at 37oC for 2 h to ensure bacterial adhesion. Contaminated biomaterial samples were implanted in the interscapular area of chinchilla rabbits for 2 and 4 weeks. The biomaterials were removed, and using plate count and sonification methods, bacterial colonization on the surface of biomaterials was determined. Moreover, the expression of TNF-α, β-defensin 2, and IL-10 in the surrounding tissues was assessed by using immunohistochemistry methods. Results. P. aeruginosa more intensively colonized biomaterials in the in vivo study as compared with S. epidermidis. Il-10 is a regulatory cytokine, which reduces the intensity of inflammatory cell activity, thus reducing nonspecific resistance of the organism. Conclusions. The expression of TNF-α and IL-10 was not affected by short (2 and 4 weeks) biomaterial implantation. Pronounced cytokine expression in tissues around implanted biomaterials contaminated with P. aeruginosa was observed.

scholarly journals Aging of Solvent-Casting PLA-Mg Hydrophobic Films: Impact on Bacterial Adhesion and Viability

Coatings ◽  
2019 ◽  
Vol 9 (12) ◽  
pp. 814 ◽  
Author(s):  
Verónica Luque-Agudo ◽  
Daniel Romero-Guzmán ◽  
María Fernández-Grajera ◽  
M. Luisa González-Martín ◽  
Amparo M. Gallardo-Moreno
Keyword(s):  
Bacterial Adhesion ◽  
Bacterial Colonization ◽  
Degradation Process ◽  
Poly Lactic Acid ◽  
Solvent Casting ◽  
Bacteriostatic Effect ◽  
Biodegradable Implant ◽  
In Vitro Degradation ◽  
Surface Changes

Biomaterials used for the manufacture of biomedical devices must have suitable surface properties avoiding bacterial colonization and/or proliferation. Most biomaterial-related infections start during the surgery. Bacteria can begin colonization of the surface of a device right after implantation or in the next few hours. This time may also be sufficient to begin the deterioration of a biodegradable implant. This work explores the surface changes that hydrophobic films of poly(lactic) acid reinforced with Mg particles, prepared by solving-casting, undergone after in vitro degradation at different times. Hydrophobicity, surface tension, zeta potential, topography, and elemental composition were obtained from new and aged films. The initial degradation for 4 h was combined with unspecific bacterial adhesion and viability tests to check if degraded films are more or less susceptible to be contaminated. The degradation of the films decreases their hydrophobicity and causes the appearance of a biocompatible layer, composed mainly of magnesium phosphate. The release of Mg2+ is very acute at the beginning of the degradation process, and such positive charges may favor the electrostatic approach and attachment of Staphylococci. However, all bacteria attached on the films containing Mg particles appeared damaged, ensuring the bacteriostatic effect of these films, even after the first hours of their degradation.

scholarly journals Vancomycin Bonded to Bone Grafts Prevents Bacterial Colonization

2010 ◽  
Vol 55 (2) ◽  
pp. 487-494 ◽  
Author(s):  
Constantinos Ketonis ◽  
Stephanie Barr ◽  
Christopher S. Adams ◽  
Irving M. Shapiro ◽  
Javad Parvizi ◽  
...  
Keyword(s):  
Bacterial Adhesion ◽  
Biofilm Formation ◽  
Bacterial Colonization ◽  
Aqueous Media ◽  
Medical Problem ◽  
Great Promise ◽  
Gram Negative ◽  
Bone Allografts ◽  
Covalently Bonded ◽  
Modified Surface

ABSTRACTInfection is an important medical problem associated with the use of bone allografts. To retard bacterial colonization, we have recently reported on the modification of bone allografts with the antibiotic vancomycin (VAN). In this report, we examine the ability of this antibiotic-modified allograft to resist bacterial colonization and biofilm formation. When antibiotic was coupled to the allograft, a uniform distribution of the antibiotic was apparent. Following challenges withStaphylococcus aureusfor 6 h, the covalently bonded VAN decreased colonization as a function of inoculum, ranging from 0.8 to 2.0 log10CFU. Furthermore, the VAN-modified surface resisted biofilm formation, even in topographical niches that provide a protected environment for bacterial adhesion. Attachment of the antibiotic to the allograft surface was robust, and the bonded VAN was stable whether incubated in aqueous media or in air, maintaining levels of 75 to 100% of initial levels over 60 days. While the VAN-modified allograft inhibited the Gram-positiveS. aureuscolonization, in keeping with VAN′s spectrum of activity, the VAN-modified allograft was readily colonized by the Gram-negativeEscherichia coli. Finally, initial toxicity measures indicated that the VAN-modified allograft did not influence osteoblast colonization or viability. Since the covalently tethered antibiotic is stable, is active, retains its specificity, and does not exhibit toxicity, it is concluded that this modified allograft holds great promise for decreasing bone graft-associated infections.

scholarly journals An In-Vitro Evaluation of Microbial Adhesion on Different Types of Orthodontic Brackets

2021 ◽  
Author(s):  
Vedant Patni ◽  
Kuldeep Dmello ◽  
Jitesh Wadhwa ◽  
Mora Sathi Rami Reddy ◽  
Atul Singh
Keyword(s):  
Bacterial Adhesion ◽  
Biofilm Formation ◽  
Artificial Saliva ◽  
Bacterial Species ◽  
Brain Heart Infusion ◽  
In Vitro Study ◽  
The Self ◽  
Orthodontic Brackets ◽  
Ceramic Brackets

Introduction: Information regarding the adhesion of bacterial species and plaque accumulation to bracket material is limited. Adequate information is needed in order to offer patients orthodontic treatment without significantly increasing their risk of developing white spots, caries, or gingival inflammation. Aim: To determine the levels of the caries-inducing S. mutans species on metallic, self-ligating and ceramic brackets and to compare the total bacterial counts and counts of species present on these bracket materials. Materials and Methods: By means of an in-vitro study, six commercially available bracket systems {3M Gemini (A), American Ortho (B), Ormco (C), Begg (D), Ceramic (E) and Self-ligating (F)} were compared. The brackets were bonded in the cell well culture plate and the agar plates were prepared. Brain heart infusion medium including bacteria and artificial saliva was introduced to each bracket system containing 10 premolar brackets and were incubated. After 72 hours, the adherent bacteria were then detached by sonication and the Colony-Forming Units (CFU) of Streptococcus mutans were calculated on each bracket and were analysed using Statistical Package for the Social Sciences (SPSS) software version 17.0 for Windows. Results: Between the different bracket types, significant differences were found in terms of biofilm formation. The Begg brackets showed the least bacterial adhesion and the self-ligating brackets showed the highest bacterial adhesion and was statistically significant among all the groups (p<0.05). Ceramic brackets also showed a higher bacterial adhesion after the self-ligating brackets. Among the three groups of metallic brackets, 3M brackets showed the least bacterial adhesion but was statistically insignificant (p>0.05). Conclusion: Different orthodontic brackets serve as different loci for biofilm formation showing that the Begg brackets are the most hygienic among all the brackets taken in this study.

scholarly journals The Use of Zwitterionic Methylmethacrylat Coated Silicone Inhibits Bacterial Adhesion and Biofilm Formation of Staphylococcus aureus

2021 ◽  
Vol 9 ◽  
Author(s):  
Franziska Woitschach ◽  
Marlen Kloss ◽  
Karsten Schlodder ◽  
Anne Rabes ◽  
Caroline Mörke ◽  
...  
Keyword(s):  
Staphylococcus Aureus ◽  
Bacterial Adhesion ◽  
Biofilm Formation ◽  
Bacterial Colonization ◽  
Thermoplastic Polyurethane ◽  
Opportunistic Pathogens ◽  
Bacterial Strains ◽  
Liquid Silicone Rubber ◽  
Liquid Silicone ◽  
Biofilm Bacteria

In recent decades, biofilm-associated infections have become a major problem in many medical fields, leading to a high burden on patients and enormous costs for the healthcare system. Microbial infestations are caused by opportunistic pathogens which often enter the incision already during implantation. In the subsequently formed biofilm bacteria are protected from the hosts immune system and antibiotic action. Therefore, the development of modified, anti-microbial implant materials displays an indispensable task. Thermoplastic polyurethane (TPU) represents the state-of-the-art material in implant manufacturing. Due to the constantly growing areas of application and the associated necessary adjustments, the optimization of these materials is essential. In the present study, modified liquid silicone rubber (LSR) surfaces were compared with two of the most commonly used TPUs in terms of bacterial colonization and biofilm formation. The tests were conducted with the clinically relevant bacterial strains Staphylococcus aureus and Staphylococcus epidermidis. Crystal violet staining and scanning electron microscopy showed reduced adhesion of bacteria and thus biofilm formation on these new materials, suggesting that the investigated materials are promising candidates for implant manufacturing.

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