Antibacterial isoeugenol coating on stainless steel and polyethylene surfaces prevents biofilm growth.

AIMS: Pathogenic bacteria can spread between individuals or between food items via the surfaces they share. Limiting the survival of pathogens on surfaces, therefore, presents an opportunity to limit at least one route of how pathogens spread. In this study, we propose that a simple coating with the essential oil isoeugenol can be used to circumvent the problem of bacterial transfer via surfaces. METHODS AND RESULTS: Two commonly used materials, stainless steel and polyethylene, were coated by physical adsorption, and the coatings were characterized by Raman spectroscopy, atomic force microscopy and water contact angle measurements. We quantified and visualized the colonization of coated and uncoated surfaces by three bacteria: Staphylococcus aureus, Listeria monocytogenes and Pseudomonas fluorescens. No viable cells were detected on surfaces coated with isoeugenol. CONCLUSIONS: The isoeugenol coating prepared with simple adsorption proved effective in preventing biofilm formation on stainless steel and polyethylene surfaces. The result was caused by the antibacterial effect of isoeugenol, as the coating did not diminish the adhesive properties of the surface. SIGNIFICANCE AND IMPACT OF THE STUDY: Our study demonstrates that a simple isoeugenol coating can prevent biofilm formation of S. aureus, L. monocytogenes and P. fluorescens on two commonly used surfaces.

Recombination in Mycoplasma hominis.

Mycoplasma hominis has been previously described as a heterogeneous species, and in the present study intraspecies diversity of 20 M. hominis isolates from different individuals was analyzed using parts of the unlinked gyrase B (gyrB), elongation factor Tu (tuf), SRalpha homolog (ftsY), hitB-hitL, excinuclease ABC subunit A (uvrA) and glyceraldehyde-3-phosphate dehydrogenase (gap) genes. The level of variability of these M. hominis genes was low compared with the housekeeping genes from Helicobacter pylori and Neisseria meningitidis, but only few M. hominis isolates had identical sequences in all genes indicating the presence of recombination. In order to test for intergenic recombination, phylogenetic trees were reconstructed for each of the genes but no well-supported bifurcating phylogenetic trees could be obtained. The genes were tested for intragenic recombination using the correlation between linkage disequilibrium and distance between the segregating sites, by the homoplasy ratio (H ratio), and by compatibility matrices. The gap gene showed well-supported evidence for high levels of recombination, whereas recombination was less frequent and not significant within the other genes. The analysis revealed intergenic and intragenic recombination in M. hominis and this may explain the high intraspecies variability. The results obtained in the present study may be of importance for future population studies of Mycoplasma species.

Doctors' requirements for reproducibility of diagnostic information.

Two radiologists independently assessed 100 leg vein phlebograms for the presence or absence of deep venous thrombosis. In a subsequent questionnaire, 66 physicians were asked to state the level of agreement they would require to use conventional phlebography in their diagnostic decisions, and whether they would reduce their requirements if the phlebographic technique were made less painful and less expensive. The responses indicated physicians' requirements for reproducibility of a well-known routine diagnostic method may be unrealistic, and that physicians do not consider the inconvenience of an examination to the patient or its cost in setting their requirements for diagnostic precision.

Do contrast media aggravate Fanconi's syndrome in rats? A comparison of diatrizoate, iohexol, and ioxilan.

Urine profiles (albumin, glucose, N-acetyl-beta-D-glucosaminidase [NAG], lactate dehydrogenase [LDH], L-gamma-glutamyltransferase [GGT], sodium, and phosphate) were followed for seven days after intravenous (IV) administration of either diatrizoate, iohexol, ioxilan, or saline in 24 Wistar rats with a tubular dysfunction induced by IV sodium maleate. Ioxilan and saline had a similar effect on albumin excretion, iohexol had an intermediate effect, and diatrizoate increased it significantly from day 2 to day 7. Glucosuria was significantly greater after diatrizoate than after the nonionic contrast media (CM) or saline. Diatrizoate delayed normalization of enzymuria, whereas iohexol and ioxilan did not. None of the CM affected urinary sodium or phosphate excretion. It is concluded that Fanconi's syndrome is significantly aggravated only by diatrizoate.

Urine profiles following intravenous diatrizoate, iohexol, or ioxilan in rats.

The effects of intravenous diatrizoate, iohexol, ioxilan, or saline on albumin, glucose, sodium and the enzymes N-acetyl-beta-D-glucosaminidase (NAG), lactate dehydrogenase (LDH), and L-gamma-glutamyltransferase (GGT) in the urine of 24 normal Wistar rats were followed for seven days. During the first two hours after administration of diatrizoate, all profile components changed markedly; the albumin excretion was significantly greater than following ioxilan and iohexol; glucose, LDH, and GGT excretions were significantly greater than following ioxilan. Iohexol and ioxilan caused a higher excretion of albumin, LDH, and GGT than saline. Iohexol also increased glucose and sodium levels. Glucose and GGT were significantly higher following iohexol than following ioxilan. Both high osmolar and low osmolar contrast media may cause temporary glomerular and tubular damage. Urine profile components are affected most by diatrizoate, less by iohexol, and least by ioxilan.

Characterization of the variability of a 75-kDa membrane protein in Mycoplasma hominis.

The gene p75 encoding a 75-kDa surface-exposed membrane protein P75 was cloned and sequenced from Mycoplasma hominis type strain PG21T. To investigate the intraspecies variability, sequences were obtained from an additional two isolates 7488 and 183, and the three sequences were compared. The nucleotide and amino acid differences were not confined to specific regions of the gene/protein, but when comparing the three sequences, differences were present as single site substitutions or small insertions or deletions of nucleotides/amino acids. The intraspecies variability was further investigated by restriction enzyme analysis with two restriction enzymes (Alul and MboII) of PCR products amplified from p75 from 28 M. hominis isolates. On the basis of band patterns produced by the two restriction enzymes, the isolates could be divided into five and six groups. These groups neither matched categories of the M. hominis vaa gene nor the M. hominis p120 gene classes, indicating that the three genes vary by different mechanisms and possibly indicating horizontal gene transfer. Federation of European Microbiological Societies.

Cloning, sequencing and variability analysis of the gap gene from Mycoplasma hominis.

The gap gene encodes the glycolytic enzyme glyceraldehyde 3-phosphate dehydrogenase (GAPDH). The gene was cloned and sequenced from the Mycoplasma hominis type strain PG21(T). The intraspecies variability was investigated by inspection of restriction fragment length polymorphism (RFLP) patterns after polymerase chain reaction (PCR) amplification of the gap gene from 15 strains and furthermore by sequencing of part of the gene in eight strains. The M. hominis gap gene was found to vary more than the Escherichia coli counterpart, but the variation at nucleotide level gave rise to only a few amino acid substitutions. To verify that the gene was expressed in M. hominis, a polyclonal antibody was produced and tested against whole cell protein from 15 strains. The enzyme was expressed in all strains investigated as a 36-kDa protein. All strains except type strain PG21(T) showed reaction to a 104-kDa band in addition to the expected 36-kDa band. The protein reacting at 104 kDa is a M. hominis protein with either an epitope similar to one on GAPDH, or it is an immunoglobulin binding protein.

Evaluation of real-time quantitative PCR for identification and quantification of Chlamydia pneumoniae by comparison with immunohistochemistry.

Chlamydia pneumoniae is a common cause of community-acquired pneumonia and it has been associated with atherosclerosis. C. pneumoniae has usually been diagnosed by serology using a microimmunofluorescence test, but more recently polymerase chain reaction (PCR) has been viewed as an advantageous alternative. We developed a quantitative real-time PCR for detection of C. pneumoniae. Primers were targeted for the pmp4 gene, and the PCR fragment was detected real-time with a fluorescence resonance energy transfer probe set using a LightCycler instrument. The PCR was used on DNA released from 50 microm sections of paraffin-embedded formalin-fixed lung tissue from experimentally infected mice. Thereby, the number of C. pneumoniae genomes was determined. To our knowledge this is the first time quantification of C. pneumoniae DNA has been attempted on paraffin-embedded formalin-fixed tissue. C. pneumoniae-specific immunohistochemistry (IHC) was done on 5 microm sections adjacent to the sections used in PCR, and the number of inclusions were counted in each section. Good correlation was found when comparing results from PCR and IHC, which is in contrast to many previous studies.

Relief of metastatic obstruction in porta hepatis by endoprosthesis.

Percutaneous insertion of an internal endoprosthesis was attempted in 22 patients with obstructive jaundice due to metastatic lesions in the porta hepatis. The primary tumors were located outside the pancreas and the biliary tract. Insertion was successful in 16 patients. The endoprosthesis normalized the plasma bilirubin in 10 patients and improved the general condition in 12. The median survival was short when hepatic metastases were present. Insertion of an endoprosthesis is an attractive alternative to other palliative procedures.

New techniques for stenting severely strictured or occluded ureters.

Percutaneous stenting of the severely strictured ureter is facilitated by catheterization through a rigid curved tube leading through the kidney. Alternatively, bidirectional traction tensioning of a guide wire pulled through the entire urinary tract permits antegrade dilatation and stent drainage. Complete occlusion near the ureteric orifice may be bypassed by transureteral puncture of the bladder followed by stent insertion.

A new transhepatic endoprosthesis to prevent dislodgement.

A new transhepatic endoprosthesis, a so-called screw endoprosthesis with a spiral-shaped elevation to prevent dislodgement, is presented. The elevation is created by a silver wire wound around the endoprosthesis. Further, the wire may be used as a marker for radiotherapy or for taking biopsies, and it makes it easier to control the position of the endoprosthesis. The screw endoprosthesis was used in 22 patients, including 9 patients with high strictures in which dislodgement is known to be frequent, and 2 patients in whom previously inserted ordinary endoprostheses had been dislodged. The insertion of the screw endoprosthesis was easy. The complication rate was similar to that of ordinary transhepatic endoprosthesis. No cases of dislodgement were observed.

[Transjugular intrahepatic portosystemic shunt. Treatment of patients with recurrent bleeding from esophageal varices]. / Transjugular intrahepatisk portosystemisk shunt. Behandling af patienter med recidiverende esophagusvariceblødning.

We report the results of transjugular intrahepatic portosystemic shunt (TIPS) procedure in six patients with liver cirrhosis and recurrent bleeding or acute intractable bleeding from oesophageal varices in spite of multiple sessions of sclerotherapy. Median follow-up was 15 months (range 1-24 months). The procedure was technically successful in all patients without procedure-related morbidity or mortality. Four of the procedures were performed electively and two as an emergency procedure. The portosystemic pressure gradient decreased to below 12 mmHg following TIPS implantation and the shunt bloodflow was one quarter to three-quarters of the portal bloodflow determined by Doppler ultrasound. Recurrent bleeding occurred in one patient but was amenable to endoscopic sclerotherapy. In this patient the shunt had developed a stenosis that was treated by balloondilatation and insertion of an additional stent six months following the initial procedure, and no further bleeding occurred. The remaining five patients had no rebleeding episodes. Repeated Doppler examinations in the followup period demonstrated patency of all shunts. None of the patients developed portosystemic encephalopathy. One patient died of cerebral haemorrhage, unrelated to TIPS, 16 months following implantation. Another patient died 14 months following TIPS due to acute mesenteric occlusion and septicaemia. We conclude that TIPS is feasible and effective in selected patients with liver cirrhosis and persistent or recurrent variceal bleeding following repeated endoscopic therapy.