scholarly journals The Fate of Osteoblast-Like MG-63 Cells on Pre-Infected Bactericidal Nanostructured Titanium Surfaces

Materials ◽  
2019 ◽  
Vol 12 (10) ◽  
pp. 1575 ◽  
Author(s):  
Jason V. Wandiyanto ◽  
Vi Khanh Truong ◽  
Mohammad Al Kobaisi ◽  
Saulius Juodkazis ◽  
Helmut Thissen ◽  
...  
Keyword(s):  
Pathogenic Bacteria ◽  
Titanium Implants ◽  
The Body ◽  
Eukaryotic Cells ◽  
Resistant Bacteria ◽  
Bacterial Cells ◽  
Load Bearing ◽  
Nanostructured Titanium ◽  
Nanostructured Surfaces ◽  
Titanium Surfaces

Biomaterials that have been newly implanted inside the body are the substratum targets for a “race for the surface”, in which bacterial cells compete against eukaryotic cells for the opportunity to colonize the surface. A victory by the former often results in biomaterial-associated infections, which can be a serious threat to patient health and can undermine the function and performance of the implant. Moreover, bacteria can often have a ‘head start’ if implant contamination has taken place either prior to or during the surgery. Current prevention and treatment strategies often rely on systemic antibiotic therapies, which are becoming increasingly ineffective due to a growing prevalence of antibiotic-resistant bacteria. Nanostructured surfaces that kill bacteria by physically rupturing bacterial cells upon contact have recently emerged as a promising solution for the mitigation of bacterial colonization of implants. Furthermore, these nanoscale features have been shown to enhance the adhesion and proliferation of eukaryotic cells, which is a key to, for example, the successful osseointegration of load-bearing titanium implants. The bactericidal activity and biocompatibility of such nanostructured surfaces are often, however, examined separately, and it is not clear to what extent bacterial cell-surface interactions would affect the subsequent outcomes of host-cell attachment and osseointegration processes. In this study, we investigated the ability of bactericidal nanostructured titanium surfaces to support the attachment and growth of osteoblast-like MG-63 human osteosarcoma cells, despite them having been pre-infected with pathogenic bacteria. MG-63 is a commonly used osteoblastic model to study bone cell viability, adhesion, and proliferation on the surfaces of load-bearing biomaterials, such as titanium. The nanostructured titanium surfaces used here were observed to kill the pathogenic bacteria, whilst simultaneously enhancing the growth of MG-63 cells in vitro when compared to that occurring on sterile, flat titanium surfaces. These results provide further evidence in support of nanostructured bactericidal surfaces being used as a strategy to help eukaryotic cells win the “race for the surface” against bacterial cells on implant materials.

The Influence of the Operating Parameters of Titanium Electropolishing to Obtain Nanostructured Titanium Surfaces

2012 ◽  
Vol 727-728 ◽  
pp. 1638-1642
Author(s):  
Leonardo Marasca Antonini ◽  
Rafael Gomes Mielczarski ◽  
Caroline Pigatto ◽  
Iduvirges Lourdes Müller ◽  
Célia de Fraga Malfatti
Keyword(s):  
Operating Parameters ◽  
Nanostructured Titanium ◽  
Nanostructured Surfaces ◽  
Force Microscopy ◽  
Angle Measurements ◽  
Atomic Force ◽  
Different Temperatures ◽  
Titanium Surfaces

Titanium and Ti alloys have been widely used as biomaterial due to their mechanical properties and high in vitro and in vivo cytocompatibility. Studies have showed that the acceleration of the osseointegration process is associated to the modification of the surface morphology. The aim of this work is to study the influence of the operating parameters of titanium electropolishing to obtain nanostructured titanium surfaces. The titanium electropolishing was carried out with different temperatures (7°C, 18°C and 25°C), current density of 0.19 A/cm2 and electropolishing time of 8 minutes. After the electropolishing process the titanium samples were characterized by Atomic Force Microscopy, profilometry (mechanical profilometer) and contact angle measurements. Preliminary results showed that the Ti nanostructured surfaces formation, strongly depends on the control of operating parameters.

Peculiarities of the ultrastructure of mixed biofilms of the causing agent of diphtheria and conditionally pathogenic microorganisms isolated from the human respiratory tract

2021 ◽  
Vol 66 (10) ◽  
pp. 623-628
Author(s):  
V. N. Gerasimov ◽  
Galina Georgievna Kharseeva ◽  
O. S. Sherbataya ◽  
S. A. Kotov ◽  
A. V. Chepusova
Keyword(s):  
Respiratory Tract ◽  
Electron Microscopic Examination ◽  
The Body ◽  
Resistant Bacteria ◽  
Bacterial Cells ◽  
Human Respiratory Tract ◽  
Electron Microscopic ◽  
Opportunistic Bacteria ◽  
Epidemic Period ◽  
High Level

In the post-epidemic period, the circulation of the causative agent of diphtheria in the population is maintained due to the carrier of bacteria. Entering an organism with a high level of antitoxic immunity, the pathogen enters into intermicrobial interactions with representatives of the opportunistic microflora inhabiting the respiratory tract and forms a biofilm. Materials and methods. Modeling of the biofilm formation process was carried out using the strains C.diphtheriae gravis tox+№. 665, C.pseudodiphtheriticum, S.aureus. Biofilm samples were placed on the stage of a scanning electron microscope and gold-sputtered in an EicoIB-3 ioncoater vacuum deposition unit (Eico, Japan) at an ion current of 6-8 mA. The samples obtained were examined in a JEOL 6510LB scanning electronmicroscope. («JEOL» company, Japan) at an accelerating voltage of 30 kV. Results. Electron microscopic examination of samples of biofilms C. diphtheriae gravis tox+ № 665 and opportunistic microorganisms shows groups of 2-7 young bacterial cells packed into a single microcapsule. Much more voluminous accumulations of bacterial cells (more than 10-12) are typical for biofilm samples represented by C. diphtheriae gravis tox+№ 665 and S. aureus cells. On the surface of the biofilm, young bacterial cells with an intact structure are located at various stages of active division. The conglomerates of bacterial cells, covered with a common intermicrobial matrix, adhere tightly to each other and form a multilayer biofilm. Conclusion. Features of the ultrastructure of biofilms containing strains of C. diphtheriae and opportunistic bacteria, especially antibiotic-resistant bacteria inhabiting the respiratory tract, can contribute to long-term persistence of the pathogen of diphtheria in the body. They not only significantly complicate the access of antibacterial drugs, but also interfere with the isolation of C.diphtheriae during bacteriological research.

scholarly journals Synanthropic spiders, including the global invasive noble false widow Steatoda nobilis, are reservoirs for medically important and antibiotic resistant bacteria

2020 ◽  
Vol 10 (1) ◽  
Author(s):  
John P. Dunbar ◽  
Neyaz A. Khan ◽  
Cathy L. Abberton ◽  
Pearce Brosnan ◽  
Jennifer Murphy ◽  
...  
Keyword(s):  
Pseudomonas Putida ◽  
Bacterial Infections ◽  
Pathogenic Bacteria ◽  
Bacterial Species ◽  
The Body ◽  
Resistant Bacteria ◽  
Pathogenic Potential ◽  
Antibiotic Resistant ◽  
Opportunistic Bacteria ◽  
Staphylococcus Capitis

AbstractThe false widow spider Steatoda nobilis is associated with bites which develop bacterial infections that are sometimes unresponsive to antibiotics. These could be secondary infections derived from opportunistic bacteria on the skin or infections directly vectored by the spider. In this study, we investigated whether it is plausible for S. nobilis and other synanthropic European spiders to vector bacteria during a bite, by seeking to identify bacteria with pathogenic potential on the spiders. 11 genera of bacteria were identified through 16S rRNA sequencing from the body surfaces and chelicerae of S. nobilis, and two native spiders: Amaurobius similis and Eratigena atrica. Out of 22 bacterial species isolated from S. nobilis, 12 were related to human pathogenicity among which Staphylococcus epidermidis, Kluyvera intermedia, Rothia mucilaginosa and Pseudomonas putida are recognized as class 2 pathogens. The isolates varied in their antibiotic susceptibility: Pseudomonas putida, Staphylococcus capitis and Staphylococcus edaphicus showed the highest extent of resistance, to three antibiotics in total. On the other hand, all bacteria recovered from S. nobilis were susceptible to ciprofloxacin. Our study demonstrates that S. nobilis does carry opportunistic pathogenic bacteria on its body surfaces and chelicerae. Therefore, some post-bite infections could be the result of vector-borne bacterial zoonoses that may be antibiotic resistant.

MODELING THE POPULATION DYNAMICS OF ANTIBIOTIC-RESISTANT BACTERIA: AN AGENT-BASED APPROACH

2009 ◽  
Vol 20 (03) ◽  
pp. 435-457 ◽  
Author(s):  
JAMES T. MURPHY ◽  
RAY WALSHE ◽  
MARC DEVOCELLE
Keyword(s):  
Population Dynamics ◽  
Pathogenic Bacteria ◽  
Cellular Level ◽  
Resistant Bacteria ◽  
Bacterial Cells ◽  
Theoretical Understanding ◽  
Bacterial Populations ◽  
Diverse Range ◽  
Agent Based ◽  
The Individual

The response of bacterial populations to antibiotic treatment is often a function of a diverse range of interacting factors. In order to develop strategies to minimize the spread of antibiotic resistance in pathogenic bacteria, a sound theoretical understanding of the systems of interactions taking place within a colony must be developed. The agent-based approach to modeling bacterial populations is a useful tool for relating data obtained at the molecular and cellular level with the overall population dynamics. Here we demonstrate an agent-based model, called Micro-Gen, which has been developed to simulate the growth and development of bacterial colonies in culture. The model also incorporates biochemical rules and parameters describing the kinetic interactions of bacterial cells with antibiotic molecules.Simulations were carried out to replicate the development of methicillin-resistant S. aureus (MRSA) colonies growing in the presence of antibiotics. The model was explored to see how the properties of the system emerge from the interactions of the individual bacterial agents in order to achieve a better mechanistic understanding of the population dynamics taking place. Micro-Gen provides a good theoretical framework for investigating the effects of local environmental conditions and cellular properties on the response of bacterial populations to antibiotic exposure in the context of a simulated environment.

scholarly journals Lytic Bacteriophages and Phage Cocktails Seem to be a Future Alternative Against Multi-Drug Resistant Bacterial Infections

2019 ◽  
Author(s):  
Roja Rani Pallavali ◽  
Vijaya Lakshmi Degati ◽  
Vijaya Raghava Prasad Durbaka
Keyword(s):  
Bacterial Infections ◽  
Pathogenic Bacteria ◽  
Multidrug Resistant ◽  
The Body ◽  
Resistant Bacteria ◽  
Drug Resistant ◽  
Lytic Effect ◽  
Antibiofilm Agents ◽  
Near Future ◽  
Septic Wound

Lytic bacteriophages have the efficacy to act and eradicate pathogenic bacteria as an attractive tool in the near future. Bacteriophages specifically kill multidrug-resistant bacteria even which have the capacity to form biofilms. The present review mainly focused on the efficacy of bacteriophages and cocktails as therapeutic agents against predominate MDR-bacteria and their biofilms which are isolated from septic wound infections. The body of evidence includes data from studies investigating bacteriophages from sewage samples as novel antibacterial and antibiofilm agents against pathogenic bacteria. The goal of this review is to present an overview on predominant bacteria from septic wound infection, the biofilm-forming capacity of bacteria, lytic effect of bacteriophages and phage cocktails with an emphasis on the application of bacteriophages against septic wound causing bacteria.

FEATURES OF FORMATION OF MICROBIAL BIOFILMS WHEN EXPOSED TO ELECTROCHEMICALLY ACTIVATED SOLUTIONS ON THE POPULATIONS OF SOME PATHOGENIC BACTERIA

2018 ◽  
Vol 1 (4) ◽  
pp. 45-49
Author(s):  
D. A. Bannikova ◽  
◽  
A. B. Kononenko ◽  
Keyword(s):  
Pathogenic Bacteria ◽  
Morphological Changes ◽  
The Body ◽  
Bacterial Cells ◽  
Bacterial Populations ◽  
Susceptible Host ◽  
Microbial Biofilms ◽  
Initial Stage ◽  
Microscopy Techniques ◽  
Partial Destruction

Field strains of Escherichia coli, Salmonella typhimurium, Staphylococcus aureus, Proteus vulgaris, Pseudomonas aeruginosa were used as test cultures in the experiments. The method based on the cultivation of bacteria in the drops of semi-liquid agar deposited on membrane filters, which allowed not only to quantify the effect of ANC on bacterial populations, but also to study the morphological changes occurring in bacterial populations was used in the work. The use of scanning electron microscopy techniques has allowed us to assert that the action of electrochemically activated solutions leads to the partial destruction of biofilms of bacterial colonies. Separate bacterial cells with disturbed integrity of cell walls are deprived of the ability to adhesion and subsequent colonization, which determines the initial stage of the infectious process in the body of the susceptible host.

scholarly journals Dielectrophoresis assisted rapid, selective and single cell detection of antibiotic resistant bacteria with G-FETs

2019 ◽  
Author(s):  
Narendra Kumar ◽  
Wenjian Wang ◽  
Juan C. Ortiz-Marquez ◽  
Matthew Catalano ◽  
Mason Gray ◽  
...  
Keyword(s):  
Single Cell ◽  
Pathogenic Bacteria ◽  
Field Effect Transistors ◽  
Bacterial Species ◽  
Resistant Bacteria ◽  
Cell Detection ◽  
Bacterial Cells ◽  
Antibiotic Resistant Bacteria ◽  
Antibiotic Resistant ◽  
Single Cell Detection

AbstractThe rapid increase in antibiotic resistant pathogenic bacteria has become a global threat, which besides the development of new drugs, requires rapid, cheap, scalable, and accurate diagnostics. Label free biosensors relying on electrochemical, mechanical, and mass based detection of whole bacterial cells have attempted to meet these requirements. However, the trade-off between selectivity and sensitivity of such sensors remains a key challenge. In particular, point-of-care diagnostics that are able to reduce and/or prevent unneeded antibiotic prescriptions require highly specific probes with sensitive and accurate transducers that can be miniaturized and multiplexed, and that are easy to operate and cheap. Towards achieving this goal, we present a number of advances in the use of graphene field effect transistors (G-FET) including the first use of peptide probes to electrically detect antibiotic resistant bacteria in a highly specific manner. In addition, we dramatically reduce the needed concentration for detection by employing dielectrophoresis for the first time in a G-FET, allowing us to monitor changes in the Dirac point due to individual bacterial cells. Specifically, we realized rapid binding of bacterial cells to a G-FET by electrical field guiding to the device to realize an overall 3 order of magnitude decrease in cell-concentration enabling a single-cell detection limit, and 9-fold reduction in needed time to 5 minutes. Utilizing our new biosensor and procedures, we demonstrate the first selective, electrical detection of the pathogenic bacterial species Staphylococcus aureus and antibiotic resistant Acinetobacter baumannii on a single platform.

scholarly journals The role of probiotics on animal health and nutrition

2021 ◽  
Vol 82 (1) ◽  
Author(s):  
Ismat Jahan Anee ◽  
Shamimul Alam ◽  
Rowshan Ara Begum ◽  
Reza Md Shahjahan ◽  
Ashfaqul Muid Khandaker
Keyword(s):  
Pathogenic Bacteria ◽  
Molecular Mechanisms ◽  
Well Being ◽  
Review Article ◽  
The Body ◽  
Effective Alternative ◽  
Resistant Bacteria ◽  
Main Body ◽  
Growth Promoter ◽  
Suitable Alternative

Abstract Background The constant global need for food has created a demand for colossal food production. Every day the world requires more food than it is capable of growing and harvesting. Antibiotics have been used in healthy food products to promote growth and prevent disease in food-producing animals for a long time. This prolonged use of antibiotics leads to the development of resistant bacteria and the accumulation of antibiotic residue in livestock and fish. To avoid further causalities finding an effective alternative became a dire need. At present, the most suitable alternative for antibiotics is probiotics. Main body Probiotics are live microorganisms that provide health benefits when consumed or applied to the body with the optimum amount. Probiotics are mainly good bacteria and yeast which fight off the pathogenic bacteria, improve the immune system, and restore the gut microbial balance. Probiotics can eliminate the harmful pathogens following several molecular mechanisms and modulate the immune response of the host animal for the well-being of the animals. This review article aims to describe probiotics as a potential growth promoter in major food sectors (poultry, ruminant, and aquaculture), how probiotics can ensure food safety without harmful effects on animals, and find out some points where more research is required to ensure a positive outcome. Conclusion The conclusion of this review article highlights the knowledge gaps and how they can be minimized using modern molecular technologies to establish probiotic supplements as an effective alternative to antibiotics.

Outsmarting superbugs: bactericidal activity of nanostructured titanium surfaces against methicillin- and gentamicin-resistantStaphylococcus aureusATCC 33592

2019 ◽  
Vol 7 (28) ◽  
pp. 4424-4431 ◽  
Author(s):  
Jason V. Wandiyanto ◽  
Samuel Cheeseman ◽  
Vi Khanh Truong ◽  
Mohammad Al Kobaisi ◽  
Chantal Bizet ◽  
...  
Keyword(s):  
Antibiotic Resistance ◽  
Bactericidal Activity ◽  
Pathogenic Bacteria ◽  
Rapid Rise ◽  
Significant Issue ◽  
Nanostructured Titanium ◽  
Biomaterial Surfaces ◽  
Titanium Surfaces

The colonisation of biomaterial surfaces by pathogenic bacteria is a significant issue of concern, particularly in light of the rapid rise of antibiotic resistance.

Attachment of oral bacteria to titanium surfaces: An SEM study

1994 ◽  
Vol 52 ◽  
pp. 468-469
Author(s):  
J. E. Laffoon ◽  
R. L. Anderson ◽  
J. C. Keller ◽  
C. D. Wu-Yuan
Keyword(s):  
Technical Problem ◽  
Titanium Implant ◽  
Oral Bacteria ◽  
Bacterial Cells ◽  
Thin Sections ◽  
Surface Ultrastructure ◽  
Sem Study ◽  
Key Factor ◽  
Titanium Surfaces

Titanium (Ti) dental implants have been used widely for many years. Long term implant failures are related, in part, to the development of peri-implantitis frequently associated with bacteria. Bacterial adherence and colonization have been considered a key factor in the pathogenesis of many biomaterial based infections. Without the initial attachment of oral bacteria to Ti-implant surfaces, subsequent polymicrobial accumulation and colonization leading to peri-implant disease cannot occur. The overall goal of this study is to examine the implant-oral bacterial interfaces and gain a greater understanding of their attachment characteristics and mechanisms. Since the detailed cell surface ultrastructure involved in attachment is only discernible at the electron microscopy level, the study is complicated by the technical problem of obtaining titanium implant and attached bacterial cells in the same ultra-thin sections. In this study, a technique was developed to facilitate the study of Ti implant-bacteria interface.Discs of polymerized Spurr’s resin (12 mm x 5 mm) were formed to a thickness of approximately 3 mm using an EM block holder (Fig. 1). Titanium was then deposited by vacuum deposition to a film thickness of 300Å (Fig. 2).

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