Subcutaneous implanted chambers in different mouse strains as an animal model to study genetic stability during infection with Lyme disease Borrelia.

Tissue metal net cages were implanted subcutaneously in BALB/cJ and C3H/Tif mice as an experimental model of Borrelia burgdorferi infection. B. burgdorferi sensu stricto strain Sh2-82 could be isolated up to 14 weeks after the inoculation. However, a significant difference in infectivity between the two mice strains was observed. C3H/Tif mice were more susceptible to developing chronic B. burgdorferi s.s. infections than BALB/cJ mice. Although a B. burgdorferi infection was established, no rearrangements in the ospA and ospB genes were observed in any of the infected mice.

Inhibitory effect of zinc oxide on contact allergy due to colophony.

Contact allergy to a wound dressing with an adhesive mass consisting of colophony, zinc oxide and rubber (Mezinc) was studied in 179 patients with a history of eczema. 12 patients were found to be allergic to colophony, whereas only 4 of these patients also showed a positive patch test reaction to the wound dressing. 14 patients with verified moderate contact allergy to colophony were patch tested with adhesive mass (10%), Portuguese colophony (10%), zinc oxide (10%), purified resin acids (10%), and Portuguese colophony (10%), in combination with zinc oxide. Only 3 patients reacted to the adhesive mass, whereas all patients showed a positive patch test reaction to Portuguese colophony. A combination of zinc oxide (10%) with Portuguese colophony (10%) provoked a positive patch test reaction in only 5 of these 14 patients. An allergic reaction to abietic acid (90-95% purity) was found in 7 patients and to neoabietic acid (99 + %) in 3 patients, whereas no reactions to dehydroabietic (99 + %), isopimaric (99 + %) or levopimaric acids (98 + %) were found.

The effect of zinc oxide on Staphylococcus aureus and polymorphonuclear cells in a tissue cage model.

The effect of zinc oxide on S. aureus (209 P) was studied in steel net tissue cages implanted subcutaneously in guinea pigs and rabbits. Zinc oxide installed in the tissue cages created high, sustained concentrations of zinc in the cage fluid throughout the study. In a concentration of 22 mmol/l zinc oxide reduced viable counts in tissue cage fluid inoculated with S. aureus. No deleterious effect was observed on polymorphonuclear cell function.

Antibacterial effect of zinc oxide in vitro.

Antibacterial activity, zinc concentrations and pH were measured in Müller-Hinton broth containing different amounts of zinc oxide and inoculated with Staphylococcus aureus (10(6) colony forming units/ml). The minimum inhibitory concentrations (MIC) of zinc oxide to different clinical isolates were determined using the Müller-Hinton agar dilution tests. Gram-positive bacteria were most susceptible. Gram-negative aerobic bacteria and streptococci were usually not inhibited even at the highest concentrations used (1024 micrograms/ml), but staphylococci--particularly some isolates of Staphylococcus epidermidis--were sensitive enough to allow determination of their MIC.

Antibacterial activity of rosin and resin acids in vitro.

The antibacterial effects of rosins and resin acids were studied in vitro using three methods, disc diffusion on agar, agar dilution, and broth dilution. Rosin and some resin acids had antibacterial effects that were restricted to Gram-positive bacteria. The abietic type of acids had a more pronounced antibacterial activity than the pimaric and labdane acids when the disc diffusion method was used but there was no inhibition of growth of Gram-negative bacteria. Among the individual resin acids, dehydroabietic acid was generally the most potent, when disc diffusion on agar was used, and prediffusion increased the inhibitory effect. The composition of the pure resin acids dehydroabietic, neoabietic, and isopimaric acid did not change during the experiment, but abietic and levopimaric acid were converted into dehydroabietic acid by the addition of Müller-Hinton agar. In conclusion the old tradition of treating wounds with pitch, sap, rosin, or rosin containing tapes might therefore have some antibacterial relevance.

The incidence of bacteria in gallbladder bile at acute and elective cholecystectomy.

Aerobic and anaerobic bacterial cultivation was carried out on gallbladder bile collected from all patients operated on with cholecystectomy during a 10-month period. Acute cholecystectomy was performed on 34 patients because of acute cholecystitis. Elective cholecystectomy was performed on 177 patients because of non-acute gallbladder pathology. Bacteria were found in gallbladder bile in 16.4% of patients with non-acute cholecystopathy compared to 58.8% of patients with acute cholecystitis (p less than 0.001). An increased incidence of pathogenic bacteria was observed in the acute compared to the elective cholecystectomy material. The acute inflammatory process, its severity and the age of the patient seemed to be important factors which could be related to the increased occurrence of bacteria in the gallbladder bile. A higher incidence of postoperative morbidity and infectious complications was found in patients with pathogenic bacteria in gallbladder bile than in patients with no growth of bacteria or opportunistic bacteria in gallbladder bile.

Elective cholecystectomy with intraperitoneal drain. A bacteriological evaluation.

The occurrence of bacteria in 108 patients operated on with elective cholecystectomy was investigated in specimens from preoperative skin, gallbladder bile, drain wound secretion and drainage fluid. Growth of bacteria in gallbladder bile was found in 13% and in drainage fluid in 46% of the patients. The occurrence of bacteria in drainage fluid was not correlated with the operative time or the experience of the surgeon. The presence of pathogenic bacteria in the drainage fluid in our investigation was related to increased amounts of drainage fluid and to increased incidence of infectious complications (manifest or suspected intra-abdominal abscess and wound infection). Growth of bacteria analogous to those found in drainage fluid was observed in gallbladder bile (5% of the patients), in preoperative skin culture (12%) and in drain wound secretion (14%). Most of the bacteria in the drainage fluid seemed to come from an exogenic source. However, in 35% of the patients with bacteria in the gallbladder bile analogous bacteria were demonstrated in the drainage fluid. Since an increased occurrence of bacteria in gallbladder bile has been found in patients with acute cholecystitis and in patients more than 60 years of age the use of intraperitoneal drain from a bacteriological point of view could thus be limited to these groups of patients.

Ampicillin treatment of Neisseria gonorrhoeae in vivo. An experimental study in rabbits.

The effect of ampicillin on gonococci was investigated in chambers subcutaneously implanted in rabbits. An intramuscular injection of ampicillin resulted in a rapid increase of the ampicillin concentration in serum, whereas the diffusion of ampicillin into the fluid of a non-infected chamber was comparatively slow. The ampicillin concentration was, however, maintained in the chamber fluid during a prolonged period of time as compared to ampicillin in serum. The concentration profile of ampicillin in the infected chamber was similar to that of the non-infected chamber, though at a lower level. No viable gonococci were detected 120 minutes after the injection of ampicillin. In contrast, the same concentration of ampicillin in a liquid culture resulted in slower reduction in the viability of the gonococcal strain. Even after 300 minutes a small population of gonococci was viable. Thus, a difference in the activity of ampicillin could be observed between the in vitro and the in vivo test situation.

Hereditary palmo-plantar keratoderma: incidence of dermatophyte infections and the results of topical treatment with retinoic acid.

Thirty-four patients with hereditary palmo-plantar keratoderma (HPPK) were examined with regard to dermatophyte infections. Twenty-two of the patients (65%) had dermatophytosis, a figure indicating a predisposition of this type of infection. E. floccosum was found in %0% of the HPPK patients as compared with 17% of the dermatophytoses of palms and soles in non-HPPK patients (p less than 0.01). Topical treatment of HPPK with 0.05% retinoic acid without occlusion had no observable effect.

Clinical trial of a potent non-halogenated topical steroid, Budesonide.

In a double-blind, randomized multi-centre study, 116 patients with psoriasis have been treated for 1-3 weeks with budesonide ointment (Preferid, Draco/Tika; a subsidiary of AB ASTRA), a new non-halogenated topical steroid. In a series of 11 patients a 0.025% budesonide ointment was significantly superior to placebo. In a second series, of 54 patients, a 0.025% fluocinolone acetonide ointment (Synalar, ICI). In a third series, of 51 patients, a 0.010% budesonide ointment was compared with 0.025% fluocinolone acetonide ointment. No statistically significant difference between these two preparations was found to exist. No adverse reactions were observed.

Zinc tape treatment of burns infected by Pseudomonas aeruginosa: an experimental study on guinea pigs.

Third-degree burns on guinea pigs were infected with Pseudomonas aeruginosa. The wounds were treated with a zinc tape, a gauze sponge, or a plastic foil. In tissue specimens from the wounds, less growth of Pseudomonas was found in zinc tape treated wounds than in gauze- or plastic foil treated wounds. In vitro it was found that zinc oxide possesses an antibacterial effect on Pseudomonas aeruginosa, Staphylococcus aureus and Streptococcus pyogenes.

Cefuroxime treatment of urethritis caused by a beta-lactamase-producing strain of Neisseria gonorrhoeae.

A patient who contracted urethritis from a beta-lactamase-producing strain of Neisseria gonorrhoeae was successfully treated with the cephalosporin derivative cefuroxime. As expected, neither cefuroxime nor cefamandole was hydrolysed by plasmid-coded gonococcal beta-lactamase. Cefuroxime ought to be a valuable and efficacious substitute for penicillins in the treatment of gonhorrhoea due to beta-lactamase-producing gonococcal strains.

Effects of low ampicillin concentrations on penicillin sensitive and beta-lactamase producing strains of Neisseria gonorrhoeae.

The effects of therapeutic concentrations of ampicillin on non-beta-lactamase and beta-lactamase producing strains of Neisseria gonorrhoeae were studied. A small but significant fraction of bacteria in a gonococcal population was found to respond in a bacteriostatic rather than a bactericidal way upon ampicillin treatment. In agreement with this was the finding of morphologically unaltered cells in the scanning electron microscope after ampicillin exposure. Ampicillin treatment of beta-lactamase producing gonococci caused a significant release of the enzyme into the surrounding growth media. However, initially all beta-lactamase activity was cellbound. The rate of initial ampicillin hydrolysis was much higher in intact cells of N. gonorrhoeae (TEM-1) than in cells of Escherichia coli K-12 (TEM-1). This suggests that the diffusion rate of ampicillin is much higher in the former organism. The viability of gonococci (TEM-1) was unlike E. coli (TEM-1) affected by low concentrations of ampicillin. However, after complete hydrolysis of ampicillin, viable gonococci (probably bacteriostatic reacting cells) were able to initiate new growth. This heterogeneity of the cell population to penicillin killing is probably one reason why beta-lactamase producing gonococci despite a rather low MIC-value to ampicillin cause infections that are not susceptible to therapy by this agent.

Survival of Neisseria gonorrhoeae on surfaces.

The survival of Neisseria gonorrhoeae was investigated. It was found that gonococci could survive 24 hours in urethral secretion on a glass slide and on a towel at 22 degrees C, and 120 hours at 4 degrees C. A method was developed by which the survival of gonococci could be followed in vitro. With this method, gonococci grown in vitro were found to be protected by human serum, in contrast to gonococci resuspended in NaCl. The factors affecting the survival are discussed.

Growth pattern and cell division in Neisseria gonorrhoeae.

The gram-negative coccus Neisseria gonorrhoeae was found to grow regularly in at least two dimensions. Growth proceeded at a linear rate sequentially in each dimension. Growth in the second dimension (former width) was initiated slightly before the pole-division plane distance equalled the cell width. Penicillin treatment localized presumptive growth zones to the existing septum region. It was suggested that new growth zones were always formed perpendicular to the longitudinal axis created in the incipient daughter cells of a dividing coccus. Neither penicillin nor nalidixic acid induced filaments of N. gonorrhoeae. Such structures could nevertheless be formed in the rod-shaped species Neisseria elongata. N. gonorrhoeae divides by septation; however, complete septal structures with separated cytoplasms were rather infrequent. It is proposed that N. gonorrhoeae be regarded as a short rod which always extends parallel to the actual longitudinal axis and which never undergoes a rod-sphere-rod transition.

Autolysis of Neisseria gonorrhoeae. Relation between mechanical stability and viability.

The relationship between the mechanical stability and the viability of N. gonorrhoeae (Type 4) in suspension was investigated. A correlation between viability and optical density recordings was often found. However, in spite of increased mechanical stability in solutions with low pH (5-2) or containing Cu++ or sucrose (10 per cent.), these environments were toxic to the gonococci. A viability preserving effect by Mg++ (4 mM), Ca++ (4 mM), spermine (0-5 mM), polyvinylpyrrolidone (10 per cent.), and low temperature (4 degrees C) was demonstrated. The possibility of improving transport media for gonococci is discussed.