Adhesion of Lactobacillus acidophilus, Escherichia coli and Staphylococcus epidermidis to polymer and urinary catheter surfaces

Synthesis of metal incorporated low molecular weight polyurethanes from novel aromatic diols, their characterization and bactericidal properties

Low molecular weight polyurethanes with sites for metal complexation were synthesized. The -SO(2) and the -COOH groups were incorporated into the polyurethane chain by the reactions of tri-functional monomers, 4,4'-bis(hydroxyphenyl)sulfone and 4,4'-bis(hydroxyphenyl) valeric acid with hexa-methylene di-isocyanate (HMDI) and 2,4 toluene di-isocyanate (TDI), respectively. The reaction was monitored from the disappearance of the -OH group and results show that the -NCO groups of the isocyanate reacted with the -OH group preferentially when compared to the other reactive groups. The pristine tri-functional monomers themselves formed stable complexes with the metals and so were chosen to be incorporated into the polyurethane chain. These polymers were characterized by IR and NMR spectroscopy. The free -SO(2) and the -COOH groups were used for metal complexation using non-toxic metals like zinc and silver. The anti-bacterial studies conducted on the six polymers in film form showed interesting results as elaborated in the paper.

Biomaterials in Urology II: future usage and management

It seems likely, and indeed inevitable, that medical device usage will continue its rapid increase over the next 10 to 20 years and beyond. For surgeons, these new inventions will come in many forms but should take into account biocompatibility and resistance to encrustations and to microorganisms. This review focuses on research under way at present in vitro and in vivo on materials and coatings, use of bioelectrics, use of artificial organs and tissues, application of indigenous bacteria, and other alternative device management techniques, which could well become part of clinical practice in the future. By necessity, some of these citations are speculative, but supporting documentation for their inclusion is presented.

Bacterial adhesion to polymer surfaces: a critical review of surface thermodynamic approaches

This paper presents a review of the theories based on wetting measurements/interfacial thermodynamics most frequently used to explain bacterial adhesion to solid surfaces. The physical meaning of data stemming from the application of the different theories is discussed and compared with current knowledge on interactions between components of matter. It is underlined that existing theories are either in disagreement with accepted knowledge on interfacial interactions or yield conflicting results from a quantitative point of view. It is concluded that, according to the present state of the art, no completely satisfactory theory exists, and that theoretical and experimental difficulties still hinder the understanding of the relationship between surface/interface free energy and bacterial adhesion to solid substrates. The recognition of existing shortcomings should be the first step towards a more satisfactory state of the art.

Staphylococcus epidermidis adhesion to films deposited from hydroxyethylmethacrylate plasma

The adhesion of S. epidermidis ATCC 35984 strain on polystyrene (PS) disks coated by films deposited from hydroxyethylmethacrylate (HEMA) plasma was evaluated and compared to adhesion on untreated PS and oxygen-plasma-treated PS. Films were deposited keeping constant the monomer flow rate while the discharge power ranged from 40-100 W in order to obtain coating with different surface properties. Surface chemistry, energetics, and morphology were evaluated by Electron Spectroscopy for Chemical Analysis (ESCA), contact angle measurement, and Atomic Force Microscopy (AFM), respectively. Bacteria adhered more to the plasma-deposited or plasma-treated surfaces than to untreated PS, but no significant difference was recorded among the samples obtained using different deposition conditions. According to the surface energetic analysis, plasma-deposited and plasma-treated surfaces bear a strong Lewis-base character, so it is possible to hypothesize a marked contribution of electron donor-electron acceptor interactions to the mechanism(s) controlling adhesion between synthetic and bacterial surfaces.

Bacterial adhesion to orthopedic implant polymers

The degradable polymers poly(orthoester) (POE), poly(L-lactic acid) (PLA), and the nondegradable polymers polysulfone (PSF), polyethylene (PE), and poly(ether ether ketone) (PEEK) were exposed to cultures of Staphylococcus epidermidis, Pseudomonas aeruginosa, or Escherichia coli. Bacteria washed and resuspended in phosphate buffered saline (PBS) adhered to polymers in amounts nearly twice those of bacteria that were left in their growth medium, tryptic soy broth (TSB). In TSB, there was variation in adhesion from species to species, but no significant variation from polymer to polymer within one species. In PBS there were significant differences in the amounts of bacteria adhering to the various polymers with the exception, of S. epidermidis, which had similar adhesion to all polymers. As a whole, P. aeruginosa was the most adherent while S. epidermidis was the least adherent. The estimated values of the free energy of adhesion (delta Fadh) correlated with the amount of adherent P. aeruginosa. When POE, PLA, and PSF were exposed to hyaluronic acid (HA) before exposure to the bacteria, there was 50% more adhesion of E. coli and P. aeruginosa on POE and PLA. With respect to bacterial adhesion, the biodegradable polymers (POE and PLA) in general were not significantly different from the nondegradable polymers.

Adhesion of lactobacilli to urinary catheters and diapers: effect of surface properties

Thirteen strains of lactobacilli were tested for their ability to adhere to commercial devices used in the urinary tract. Although it appeared that the most hydrophilic organisms adhered in highest numbers, there was no significant correlation between water contact angle and adhesiveness to catheters. Five organisms tested were found to be highly adherent to Huggies commercial diapers. Loss in hydrophobicity upon serial culture of Lactobacillus fermentum B-54 was not due to a proteinaceous S layer, although protein involvement per se cannot be ruled out. It was evident that, not only can members of the normal female urogenital flora adhere to commonly used commercial prostheses, but their ability to attach is related to hydrophilic as well as hydrophobic surface components.

Applications from bacterial adhesion and biofilm studies in relation to urogenital tissues and biomaterials: a review

The urogenital tract, particularly of the adult female, is the habitat for many species of microorganisms. These populations are in a state of flux, are susceptible to disruption by antibiotics and spermicides, and are exposed to many different biomaterial substrata. Infections of the genital area and bladder are common, and are invariably initiated by microbial adhesion to surfaces. This review examines the actual and potential applications to industry and to patients emerging from the study of bacterial adhesion to surfaces.