[Determination of a Spectrum of Lytic Activity of Bacteriophages by the Method of Acoustic Analysis].

The changes in the electro-acoustic parameters of cell suspension due to the interaction of cells with bacteriophages both in a pure. culture and in the presence of extraneous microflora were investigated. It has been found that the specific changes in the electroacoustic parameters of cell suspension under the action of bacteriophage occur only in microbial cells which are sensitive to the bacteriophage studied. It has been established that a sensor unit allows of distinguishing a situation when the bacterial cells are infected with specific bacteriophages of the control experiments and a situation with no introduction of infection. An approximate criterion of the presence of specific interactions of bacteriophages and cells in suspension was developed. In accordance with this criterion the change in electrical impedance of the sensor unit must not be less than - 1%. In control experiments a standard microbiological technique, plating the cells infected with bacteriophages on solid nutrient medium, was used. For the first time the possibility of using the method of electroacoustic analysis for determination of a spectrum of lytic activity of bacteriophages was shown. The results obtained may be used for development of a new express method for determining the sensitivity to bacteriophages of the microbial cells.

Antibodies to prion and Acinetobacter peptide sequences in bovine spongiform encephalopathy.

An amino acid sequence homology has been identified between the bovine prion sequence (RPVDQ) and the Acinetobacter calcoaceticus enzyme, uridine-diphosphate-N-acetyl glucosamine-1-carboxy-vinyl-transferase which also contains (RPVDQ). Class-specific IgA, IgG and IgM antibodies against synthetic peptides containing the structurally related sequences present in bovine prion and A. calcoaceticus were measured in 189 bovine spongiform encephalopathy (BSE) positive cattle, 127 BSE negative cattle and 87 healthy control animals using an ELISA technique. Class-specific IgA, IgG and IgM antibodies against the structurally related synthetic peptides were significantly elevated in BSE positive cattle when compared to BSE negative cattle (P < 0.001) and healthy control animals (P < 0.001). These autoantibodies may have a role in the pathogenesis of BSE.

Failure to demonstrate involvement of antibodies to Acinetobacter calcoaceticus in transmissible spongiform encephalopathies of animals.

Acinetobacter calcoaceticus, a soil microbe, contains molecular sequences which resemble those found in neurofilaments of the brain tissue. It was hypothesized that if cattle ingest large amounts of feedstuff containing A. calcoaceticus, they may develop an autoimmune reaction, with consequences of pathological changes associated with transmissible spongiform encephalopathies (TSEs). The hypothesis was tested using a small number of serum samples collected from cattle and it was found that affected individuals had elevated serum antibody levels to this organism. If this finding was substantiated, it would provide a possible means of diagnosing TSEs in vivo. In the present communication, a larger number of cattle, elk and sheep with or without TSEs were tested using A. calcoaceticus whole cell and lipopolysaccharide antigens as well as myelin basic protein (MBP). It was found that antibody levels in normal and affected animals overlapped considerably, thus casting doubt on the usefulness of these antigens as diagnostic tools for TSEs and on the hypothesis of A. calcoaceticus being a cause of TSEs.

Identification of Acinetobacter isolates from species belonging to the Acinetobacter calcoaceticus-Acinetobacter baumannii complex with monoclonal antibodies specific for O Antigens of their lipopolysaccharides.

The unambiguous identification of Acinetobacter strains, particularly those belonging to the Acinetobacter calcoaceticus-Acinetobacter baumannii complex, is often hindered by their close geno- and phenotypic relationships. In this study, monoclonal antibodies (MAbs) against the O antigens of the lipopolysaccharides from strains belonging to the A. calcoaceticus-A. baumannii complex were generated after the immunization of mice with heat-killed bacteria and shown by enzyme immunoassays and Western blotting to be specific for their homologous antigens. Since the A. calcoaceticus-A. baumannii complex comprises the most clinically relevant species, the MAbs were subsequently tested in dot and Western blots with proteinase K-treated lysates from a large collection of Acinetobacter isolates (n = 631) to determine whether the antibodies could be used for the reliable identification of strains from this complex. Reactivity was observed with 273 of the 504 isolates (54%) from the A. calcoaceticus-A. baumannii complex which were included in this study. Isolates which reacted positively did so with only one antibody; no reactivity was observed with isolates not belonging to the A. calcoaceticus-A. baumannii complex (n = 127). To identify additional putative O serotypes, isolates from the A. calcoaceticus-A. baumannii complex which showed no MAb reactivity were subjected to a method that enables the detection of lipid A moieties in lipopolysaccharides with a specific MAb on Western blots following acidic treatment of the membrane. By this method, additional serotypes were indeed identified, thus indicating which strains to select for future immunizations. This study contributes to the completion of a serotype-based identification scheme for Acinetobacter species, in particular, those which are presently of the most clinical importance.

Autoantibodies to brain components and antibodies to Acinetobacter calcoaceticus are present in bovine spongiform encephalopathy.

Bovine spongiform encephalopathy (BSE) is a neurological disorder, predominantly of British cattle, which belongs to the group of transmissible spongiform encephalopathies together with Creutzfeldt-Jakob disease (CJD), kuru, and scrapie. Autoantibodies to brain neurofilaments have been previously described in patients with CJD and kuru and in sheep affected by scrapie. Spongiform-like changes have also been observed in chronic experimental allergic encephalomyelitis, at least in rabbits and guinea pigs, and in these conditions autoantibodies to myelin occur. We report here that animals with BSE have elevated levels of immunoglobulin A autoantibodies to brain components, i.e., neurofilaments (P < 0.001) and myelin (P < 0.001), as well as to Acinetobacter calcoaceticus (P < 0.001), saprophytic microbes found in soil which have sequences cross-reacting with bovine neurofilaments and myelin, but there were no antibody elevations against Agrobacterium tumefaciens or Escherichia coli. The relevance of such mucosal autoantibodies or antibacterial antibodies to the pathology of BSE and its possible link to prions requires further evaluation.

[Exposure to organic dust and microorganisms as a factor affecting respiratory function of workers of purebred horse farms]. / Narazenie na pyl organiczny i drobnoustroje jako czynnik wplywajacy na stan ukladu oddechowego pracowników stadniny koni.

In two farms of purebred horses, microbiological studies of the air and medical examination of the workers were performed. The concentration of microorganisms in the air were within the range 29.2-336.0 cfu x 10(3)/m3. The respirable fraction in most cases was between 30-60% of the total count. The levels of dust and endotoxin were low except for one sampling point where the concentration of endotoxin was as high as 3.44 g/m3. As many as 16 workers out of the total of 31 examined reported occurrence of work-related symptoms. However, the results of physical examination and of lung function tests were within normal range. A high proportion of workers showed a positive skin response to Saccharopolyspora rectivirgula (51.6%) and the presence of precipitins to Acinetobacter calcoaceticus (32.3%). No significant relationship could be found between the presence of symptoms and positive allergological reactions. Total medical results indicate the probability of the occurrence of Organic Dust Toxic Syndrome in high proportion of the workers.

[Hemagglutinating properties of Acinetobacter calcoaceticus]. / Hemaglutynacyjne wlasciwosci Acinetobacter calcoaceticus.

Hemagglutinating activity was tested in 309 strains of Acinetobacter calcoaceticus with fresh and tannine human, horse, sheep, bovine, chicken and guinea pig erythrocytes. Determinations were performed with 0.1% D-mannose and without it, both in temperature 37 and 22 degrees C. Hemagglutinating activity was exhibited by 75-85% of strains, more frequently cultured at 22 degrees C A. calcoaceticus var. anitratus equally frequently was agglutinating both types of erythrocytes. Strains of A calcoaceticus var. lwoffii were agglutinating only chicken erythrocytes, but were agglutinating all tannin treated erythrocytes. The observed agglutination was mannose-resistant.

[Quantitation of Acinetobacter calcoaceticus in mixed bacterial cultures by an enzyme immunoassay]. / Quantitative Bestimmung von Acinetobacter calcoaceticus in Bakteriengemischen mittels eines Enzymimmunassays.

An enzyme-linked immunosorbent assay using polyclonal antibodies from rabbits has been developed for quantification of Acinetobacter calcoaceticus. Bacteria were added to the wells of a microtiter plate coated with anti-Acinetobacter immunoglobulin. For detecting bound cells the peroxidase-labelled immunoglobulin fraction was used. Over a distinct range there is a linear correlation between bound bacteria and measured absorbance allowing a quantification of bacteria in an order from 10(7) to 10(8) per milliliter. The specificity of the assay was evaluated by the heterologous bacteria Pseudomonas putida, Pseudomonas aeruginosa, Proteus vulgaris, Escherichia coli and Citrobacter freundii. Only a minimal cross-reactivity was observed. Within a certain range of error it is possible to quantitate Acinetobacter calcoaceticus in mixtures with one or several other bacterial species. Mixed with bacteria of one other species the differences to the value for Acinetobacter calcoaceticus alone do not exceed +/- 10% with a tendency to lower values. Mixed with several other species only negative differences up to -15% were obtained. Treatment of Acinetobacter calcoaceticus with 0.5% formaldehyde results in a loss of reactivity up to 15%. In conclusion, the enzyme-linked immunosorbent assay is a useful method for quantitating bacteria not only with respect to the high sensitivity, specificity and good reproducibility but also for the minimal technical equipment and the short assay time.