Zentralblatt fur Bakteriologie, Mikrobiologie, und Hygiene. Series A, Medical microbiology, infectious diseases, virology, parasitology最新文献

In a controlled clinical trial the microflora of the cavity floor of 70 primary lower second molars with deep carious lesions were determined after caries excavation. The teeth were extracted and pulpal status was evaluated after 16 months of microbial control to determine the etiopathogenic role of germs for carious progression in dentine. 67% of the primary molars were free from pulpal inflammations. Soft carious dentine were significantly higher infected than the clinically acceptable hard dentine. Only in 40% of the cavity floors the microorganisms were eliminated. In the infected teeth basophilic microorganisms were found in causality to pulps without inflammations; acidogenic streptococci and lactobacilli were involved in pulpal inflammations. Results indicate that the latter genera of microorganisms are of etiological significance for carious progression in dentine.

By means of the cell fusion technique, two hybridoma cell lines, V-1 and H2-1 have been obtained. V-1 cells secrete monoclonal antibody against serovars icterohaemorrhagiae and dakota. The H2-1 cell line secretes serovar-specific monoclonal antibody against serovar H2. These monoclonal antibodies have been successfully used in serovar-typing of leptospires isolated in China. The results of identification of leptospires by using monoclonal antibodies showed total coincidence with that by the traditional cross agglutinin absorption test and factor antiserum method. It was confirmed by using monoclonal antibody that the serological agglutination totally paralleled with animal protection. On the basis of the study, a concept was proposed that the agglutination in vitro and the protection in vivo are different manifestations in different reaction systems from the same antibody (antibodies) stimulated by a component(s) of the surface antigen of leptospires.

The safety of patients asks for stringent standards when fixing limit values of the minimal inhibition concentration (MIC) in mg/l. It should be possible to recognize resistant bacterial strains with a low error on the basis of the recommendations of the bacteriological laboratory which are eventually important for therapy. Attention is drawn to the use of recognized methods such as DIN 58940 and 58944 and the participation in interlaboratory studies. Only such bacteria should be interpreted as "susceptible" whose MIC's are reliably below or, which is even better, much below the generally recognized average blood and tissue levels. Thus the break-points for the rating "susceptible" must be within the range of low variation. As a result, a few strains more would come within the "moderately susceptible" range. This would not exclude them from being selected if chemotherapy is performed with a correspondingly higher dosage (provided it is tolerated). Information on the chances of a success of therapy is improved in this way. A generous interpretation of pharmacokinetic data will in the end be more to the patient's detriment. In addition, there are numerous factors determining success or failure of therapy which cannot be established in vitro so that it is advisable to fix laboratory parameters in a stringent manner like that applied in the annexes (evaluation steps) to parts 3 and 4 of DIN 58940.

A total of 102 Neisseria gonorrhoeae isolates from Munich with known nutritional requirements were examined for lectin agglutination patterns using Taxonolectin panels containing 14 different plant originated lectins with known specificity. 29 different lectin agglutination patterns were found (in comparison auxotyping showed 17 different groups). All strains reacted with Concanavalin A and Trichosanthes kinlowii and did not show positive reactions with Limax flavus and Ulex europaeus I. 49 Isolates (48%) had lectin agglutination patterns associated with only four lectin groups (in comparison the four major auxotyping groups comprised 58 (57%) of the tested isolates). A correlation between auxotype and lectin agglutination pattern could not be demonstrated. Reproducibility of lectin agglutination patterns was excellent.

A total of 594 methicillin-resistant (MER) S. aureus strains originating from the Federal Republic of Germany were both tested for their susceptibility to a number of selected antimicrobial agents, and lysotyped with the international set of S. aureus typing phages. Control groups of methicillin-sensitive, but penicillin- (PER) and gentamicin-resistant (GER) strains were tested for comparison. A group of S. aureus strains susceptible to all of the agents tested was included in the statistical evaluation of the lysotyping results. 98% of the MER and 72% of the GER S. aureus strains were cross-resistant towards at least five of the other agents tested. 84 to 97% of the MER strains were resistant to erythromycin, tetracycline, kanamycin and gentamicin. The in vitro susceptibility towards lincomycin and amikacin was in the range of 50 to 60%. The strongest in vitro efficacy--both against the MER and the GER strains--was shown by vancomycin and fusidic acid. 52.9% of the MER and 47% of the GER strains, but only 12.3% of the non-resistant strains and no more than 15% of the PER strains belonged to phage-group III; a higher proportion of these latter groups reacted with phage-group I, which was rare among the MER and the GER strains (3.2% and 7.8% respectively). The most frequent phage-patterns of the MER strains were as follows: 47/75/77, 47/54/75/77/84/85, 77/84/85, 47/54/75/77/85, 6/47/54/75/77/84/85, and 55/83A. Most of the phage-group III lysotopes occurred at numerous places across the country, while mixed lysotypes were apparently more confined to certain areas. A relatively high percentage of the MER strains, but notably also of the sensitive strains was non-typable (22.1% and 24.1% respectively), whereas the PER and the GER strains had a considerably lower rate of non-typability (9.3% and 4.8% respectively). A correlation between non-typability and multiresistance was not evident.

Compared to American strains, European Borrelia burgdorferi strains revealed considerable heterogeneity of major proteins. Four strains isolated from ticks, human skin and human CSF were selected from our 23 Borrelia burgdorferi isolates. These strains and the American type strain B31 were characterized by SDS-PAGE (Coomassie Blue staining) and Western blots (using rabbit immune sera against two of the strains and two monoclonal antibodies (H5323 and H3TS) against a major outer surface protein (OspA]. The strains showed considerable differences in SDS-PAGE pattern. Corroborating the results of a previous study, we could demonstrate that the OspA (31/32K) can change from a minor to a major protein and in reverse the pC (21/22K) from a major to a minor protein during subculturing. Moreover, European strains can antigenically differ in OspA, pC and also in a further low molecular weight protein of 17/18K. To examine whether the antigenic heterogeneity of European isolates is reflected in the immune response of European patients we examined sera from patients with late manifestations of Lyme Borreliosis by Western blot using the five strains as antigens. Sera from seven patients with acrodermatitis chronica atrophicans (ACA) showed a surprisingly strong reactivity with the skin isolate. All sera had antibodies against the 17/18K protein of the skin isolate, but none was reactive with the analogous 17/18K of the other strains. On the other hand a comparable predominance of one strain was not found testing sera from patients with Lyme arthritis. One patient even had antibodies against OspA and OspB proteins of strain B31. Contrary to findings in American Lyme Disease antibodies against the OspA were rarely observed in the sera of our patients (only one patient had such antibodies) although we tested the patients sera with five different strains. Only two patients had stronger reactions with the skin isolate. These findings suggest that ACA is caused by antigenically closely related Borreliae. This could explain the finding that ACA is rarely observed in the US (US strains are antigenically closely related to strain B31). Our findings in patients with Lyme Arthritis--on the other hand--suggest that "different serotypes" can cause Lyme Arthritis. This does not exclude the possibility that Borrelia proteins are an important factor in the pathogenesis of Lyme arthritis. Finally the differences in reactivity of sera with different strains in the Western blot led us to examine whether such differences are also found in serodiagnostic tests using different strains as antigens.(ABSTRACT TRUNCATED AT 400 WORDS)

The article is divided in four parts. The first part deals with terms and definitions. After that there is given a description of the most common types of biological indicators. These two parts furnish material and introduce to the third part, a survey of the components of monitors, their functions and the criteria one has to take into consideration when designing them. The fourth and last part deals with the most essential feature of biological indicators, the resistance, its calibration, description and adjustment.

Over an eight years period about 6200 cell cultures, sera, cell culture media and supernatants were routinely monitored for contamination with mycoplasmas, bacteria and fungi. Mycoplasmas were detected in 24.0% of 4443 samples which were checked for possible contamination. In 1742 samples from a laboratory, known to have only mycoplasma free cultures, 2 were positive, both samples having an external origin. The value of routine monitoring to prevent the introduction of mycoplasma was confirmed. Culture and direct fluorescent assay using the fluorochrome bisbenzimide (Hoechst 33258) yielded comparable results. The applicability and significance of both methods is discussed. In spite of a few disadvantages the culture method is considered to be superior to the fluorescence assay, but both methods should be employed in order to obtain sufficiently reliable results. The importance of appropriate methods for the detection of mycoplasmas is stressed because of their potential influence on experimental results. The probable sources of cell culture contamination are also discussed.