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Biomedical subjects

C Krasemann

Publications and source records attributed to C Krasemann.

53 records · Page 3Linked to original sources
PubMed1977

[Growth of non-sporing anaerobes in an oxygen-free blood culture system (author's transl)].

The efficacy of the commercially available Vacutainer blood culture system to support the growth of non-sporing anaerobes was compared with two laboratory-prepared blood culture media (supplemented thioglycollate medium and brain heart infusion). The media were inoculated with 10, 100 and 1000 organisms of the species tested, and the number of colony-forming units was determined at intervals of 8-10 hrs. Analogous experiments were performed with batches of the media to which 10% vol/vol of human blood had been added. From the results obtained with strains of Bacteroides fragilis, Bacteroides thetaiotaomicron, Bacteroides splanchnicus, Sphaerophorus necrophorus, Peptostreptococcus anaerobius and Propionibacterium acnes it became obvious that growth of non-sporing anaerobes was significantly enhanced in the Vacutainer culture tubes, whereas Enterobacteriaceae and Streptococcus spp. grew equally well in all the media tested.

Bacteroidaceae↗
PubMed1977

[Susceptibility to Thiamphenicol and Chloramphenicol of Anaerobic Bacteria (author's transl)].

The in vitro susceptibility to thiamphenicol and chloramphenicol of 272 anaerobes, most of which were recent clinical isolated, was determined by broth dilution tests, With chloramphenicol, 133 anaerobic gram-negative non-sporing rods (48 Bacteroides fragilis, 13 B. thetaiotaomicron, 14 B. oralis, 16 Sphaerophorus varius etc.) had MIC values of 0.03 through 16 microng/ml. Very similar results (MIC, 0.06-16 microng/ml) were obtained with thiamphenicol. In concentrations of 4 microng/ml or less chloramphenicol inhibited 90.2% and thiamphenicol 78.95% of the strains. Strains with only moderate sensitivity to both antibiotics (MIC, 8 or 16 microng/ml) belonged to B. fragilis or other Bacteroides species. Members of the Fusobacterium and Sphaerophorus group were susceptible to less than or equal to 2 microng chloramphenicol/ml and less than or equal to 4 microng thiamphenicol/ml respectively. With both antibiotics, 102 strains of gram-positive non-sporing anaerobes (P. acnes, Peptostreptococcus spp., Peptococcus spp.) were susceptible to less than or equal to 8 microng/ml. Of 37 Clostridium isolates, 35 (belonging to C. perfringens, C. septicum, C. cadaveris etc.) were inhibited by concentrations of 8 microng/ml or less of chloramphenicol and thiamphenicol. Only one strain each of C. perfringens and Clostridium sp. had an MIC of 16 microng thiamphenicol/ml. Accordingly, resistance to thiamphenicol or chloramphenicol was not observed. A standardized monodisk agardiffusion test was performed on 40 Bacteroidaceae, 18 Peptococcaceae and 20 C, (P.) acnes strains. Only a poor correlation was observed between MIC and zone size for thiamphenicol and chloramphenicol. Therefore, inhibition zone diameter measurement cannot be regarded as a reliable method to detect chloramphenicol or thiamphenicol resistance in anaerobes. Thiamphenicol, which is virtually as active against anaerobes as chloramphenicol but lacks serious toxicity, may well play an important role in the therapy of various anaerobic infections.

Anti-Bacterial Agents↗
PubMed1976

[Tobramycin sensitivity of bacteria from the Klebsiella-Enterobacter group (author's transl)].

In 300 strains of the Klebsiella-Enterobacter group which were isolated from pathological material from the Bonn University Hospitals in early 1975, the sensitivity to tobramycin was investigated comparatively in a serial dilution test and agar diffusion test. 80% of the strains were seen to be classifiable as sensitive and further 3% as moderately sensitive. The rate to resistance corresponds to that of gentamycin. No difference in resistance behaviour was ascertained in the two bacterial species investigated. However, strains isolated from the urogenital tract are significantly more resistant than pathogens isolated from the respiratory tract.

Anti-Bacterial Agents↗
PubMed1976

[Microbiologic Investigations of experimental keratoprostheses made with hydrophilic plastics (author's transl)].

The subject of our investigations is the question: is there an increased risk of infection with eyes operated on keratoprostheses made with hydrophilic soft plastic material (HEMA)? Our first step was an analysis of the normal conjunctival spectrum of microorganism of our rabbits, operated and nonoperated. Then we made exploratory punctures of the anterior chamber of 7 eyes submitted to implantations of HEMA keratoprostheses. During a period of 10 days this puncture exudate was incubated in a culture medium. In 6 out of 7 cases, even after 10 days of incubation, no microorganisms were found. In one case after 72 hours of incubation, a poor growth of a staphylococcus was observed. It can be assumed that in this case the microorganism entered the anterior chamber during the puncture procedure. The results of these investigations confirm the calculation that the "pores" of hydrophilic plastic material are too small for penetration of microorganism.

Animals↗
PubMed1976

[Immunity against Erysipelothrix rhusiopathiae infection by means of active immunization using homologous neuraminidase (author's transl)].

Neuraminidase may play a role as a pathogenic factor in Erysipelothrix rhusiopathiae infection. The protective effect of active immunization with purified neuraminidase was therefore tested in an infection experiment in white mice. Mice were immunized 2, 4, 6, 8 or 10 times i.p. with Erysipelothrix neuraminidase. A control group received 10 injections with physiological saline. The infective dose varied between 7 and 7 x 10(7) cells. While all control animals infected with 7 x 10(1) germs died, the lethal effect could be reduced to 50% and 25% in animals immunized twice and 4 times, respectively. Only animals immunized 8 and 10 times were still partly protected against germ numbers of 10(3)-10(4). Germ numbers of 10(5) and more were almost always fatal even in highly immunized animals. Even a high immunization with neuraminidase could only lower the lethal by a maximum factor of 10(4) germs used.

Animals↗
PubMed1976

[Control of cross infection in intensive care units].

Quantitative determinations of antibiotic susceptibility established that infections occurring in intensive care units were predominantly exogenous cross infections. The most frequently isolated strains were: Klebsiella, Enterobacteriaceae, Serratia marcescens and Proteus mirabilis. The majority of the strains showed multiple resistance. Despite adequate antibiotic therapy a number of patients died of the infection. Many of the methods of disinfection were found to be inadequate, especially as regarded washbasins, face flannels, ultrasound inhalers, respirators and other apparatus. The fact that many of the isolated strains are capable of multiplying in water is not receiving sufficient attention.

Air Microbiology↗
PubMed1976

[Measurements of intraocular gentamicin concentration using hydrophilic contact lenses as drug delivery system (author's transl)].

Investigations were performed with two groups of anaesthetised rabbits to test the possibility of increasing the penetration of topically administered. Gentamicin into the eye through the use of hydrophilic contact lenses. After application of Gentamicin drops the drug concentration in the aqueous humour was biologically quantitated. In the first group one eye of the animal was fitted with a hydrophilic contact lens and the other eye was submitted to a comparative measurement. In the second group both eyes were fitted with contact lenses which had been soaked in Gentamicin solutions of two different con-entrations. The result showed an increased intraocular Gentamicin level in the eyes fitted with hydrophilic contact lenses. However, in the latter group we found low intraocular drug levels where only contact lenses soaked in Gentamicin solution were used.

Absorption↗
PubMed1975

[Incidence and resistance of pseudomonas aeruginosa 1970-1973 in hospitalized patients at the Bonn University hospital].

The resistance of Ps. aeruginosa to 100 mug carbenicillin and 30 mug gentamicin was analyzed for all strains originating from hospitalized patients between 1970 and 1973. Eighty per cent of all isolates were inhibited by 100 mug carbenicillin and 90% by 30 mug gentamicin (1973). Most Pseudomonas strains were isolated from the surgerical and pediatric departments, however the two departments seem to show different tendencies. It is concluded from the results obtained that resistant strains normally do not survive for a long time in one unit since the pattern of the resistance shows considerable differences six months later.

Carbenicillin↗
PubMed1975

[The virulence of erysipelothrix rhusiopathiae strains and their neuraminidase production (author's transl)].

We studied the virulence of 20 Erysipelothrix rhusiopathiae strains in albino mice and investigated the interdependence between virulence, growth rate, and neuraminidase production. The minimal number of germs, lethal to mice (LD100) varied among the strains between 10(1) and mor ethan 10(7) per animal. The course of the disease was also very different. Some strains killed the mice rapidly within 3 days. In other strains, however, even a very high number of bacteria caused death only 7 days after infection or later, in which cases the disease became manifest long in advance by ruffled fur and glutinous eyes. A significant correlation was found between the average neuraminidase production in different media and the virulence (p equal to 99%; Fig. 2). We found a less marked dependence between growth rate and virulence (Fig. 3). Neuraminidase activity and growth rate seem to influence virulence rather independently. This is concluded from the fact, that some virulent strains are characterized by quick growth and by producing either no neuraminidase or in small quantities only. On the other hand, neuraminidase production cannot be separated completely from growth rate. An induction of neuraminidas activity in vivo was not observed, even when the bacteria persisted in the mice over a long period of time. We therefore conclude that a short term enzyme induction is not probable.

Enzyme Induction↗