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N Schmeer

Publications and source records attributed to N Schmeer.

At least 37 records · Page 2Linked to original sources
PubMed1989

[The occurrence and significance of plasma coagulase negative staphylococci from the genital tract of horses].

Classification based on biochemical characteristics of 389 strains of plasma-coagulase-negative (plc-) staphylococci isolated from the genital tract of mares and stallions resulted in the following distribution of species: St. sciuri 130 (33.4%), St. equorum 42 (10.8%), St. xylosus 16 (4.1%), St. epidermidis 35 (9.0%), St. simulans 24 (6.2%), St. haemolyticus 33 (8.5%), St. warneri 18 (4.6%), St. lentus 12 (3.1%), St. hyicus 11 (2.8%). Strains of St. cohnii, St. capitis, St. gallinarum, St. saprophyticus and St. hominis have only been found sporadically (a. 1%). 48 (12.3%) strains could not be classified. With regard to species distribution of isolates from stallions and mares. 63.7% of the isolates from stallions belonged to St. sciuri and 9.3% to St. lentus, whereas in isolates of mares these species numbered only 24.9% and 0.4%, respectively. On the other hand the species St. equorum (14.9% vs. 6.8%), St. epidermidis (14.5% vs. 1.7%), St. haemolyticus (14.0% vs. 1.7%), St. warneri (7.7% vs. 0.8%) and St. xylosus (5.9% vs. 2.5%) predominated in mares. St. simulans was found occurring equally in mares and stallions (7.7% vs. 5.9%). Comparing the staphylococcal species of healthy mares and of mares which have not become pregnant after copulation no indication was found for a significant role of certain plc- staphylococci in infertility. All of the 389 isolates were tested for production of protein A, i.e. Fc-fragment binding receptors, using a microenzyme-assay with peroxidase-labelled rabbit immunoglobulin G. With this method cell-bound or extracellular Fc-receptors could not be detected in anyone of the plc- staphylococcal strains.(ABSTRACT TRUNCATED AT 250 WORDS)

Animals↗
PubMed1988

Evaluation of different fixatives and treatments for immunohistochemical demonstration of Coxiella burnetti in paraffin-embedded tissues.

Various fixatives and treatments such as acetone, methanol, Bouin fixative, modified Bouin fixative, 10% Formalin, modified methacarn, periodate-lysine-paraformaldehyde, acetone-methyl benzoate-xylene, and EDTA were evaluated for their effect on the immunoreactivity of Coxiella burnetii in paraffin-embedded tissues by using the avidin-biotin-peroxidase complex and the peroxidase-antiperoxidase procedure. C. burnetii antigen was shown to be present in liver, spleen, and uterus tissues of experimentally infected mice by all methods of fixation and treatment. A positive immunoreaction was seen in cytoplasmic vacuoles of macrophages, as extracellular rod-shaped organisms, and as residual particulate extra- and intracellular debris. Immunoreactivity and cellular preservation, however, varied substantially with the individual fixatives. Optimal immunostaining of C. burnetii was achieved by EDTA treatment and Bouin and acetone fixation. The avidin-biotin-peroxidase technique proved to be slightly more sensitive than the peroxidase-antiperoxidase procedure when primary antibody dilution was used as the criterion for sensitivity.

Animals↗
PubMed1988

Enzyme-linked immunosorbent fluorescence assay and high-pressure liquid chromatography for analysis of humoral immune responses to Coxiella burnetti proteins.

A microtiter enzyme-linked immunosorbent fluorescence assay based on alkaline phosphatase conjugate and 4-methylumbelliferyl phosphate as fluorogenic substrate was developed and adapted to quantitatively analyze immunoglobulin G subclass 1 (IgG1) and IgG2 responses of vaccinated and infected cattle to proteins of Coxiella burnetii. The enzyme-linked immunosorbent fluorescence assay surpassed the conventional enzyme-linked immunosorbent assay with a 50-fold-higher sensitivity and a broader range of linear dose-response signals. Antigens of C. burnetii were purified by sodium dodecyl sulfate extraction and molecular-sieve high-pressure liquid chromatography. The purified 14-, 27-, and 30-kilodalton proteins were used as antigens without any further treatment. Vaccination with either chloroform-methanol-extracted cell residues of C. burnetii or the 27-kilodalton major surface protein evoked an early IgG2 response to the 27-kilodalton protein (2 weeks after immunization), whereas IgG2 to lipopolysaccharides of C. burnetii was detected only in the late phase (13 weeks after immunization). These results may have implications for the serodiagnosis of acute and chronic Q fever. IgG1 against these antigens was induced solely by naturally occurring C. burnetii infections, indicating that infected cattle can be distinguished from vaccinated cattle by using the enzyme-linked immunosorbent fluorescence assay and SP27 antigen.

Animals↗
PubMed1987

[Q fever].

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Animals↗
PubMed1987

Dominance of Chlamydia psittaci-specific IgG2 subclass in the humoral immune responses of naturally and experimentally infected cattle.

Indirect enzyme-linked immunosorbent assays were applied to differentiate Chlamydia (C.) psittaci-specific IgG1 and IgG2 levels in 143 individual serum samples from cattle with naturally occurring chlamydial infections and in 190 sequential serum samples from 26 experimentally infected pregnant cows, calves, and a bull. The mean IgG1:IgG2 ratio of naturally infected cattle was 1:4 indicating a significant (p less than 0.001) IgG2 dominance. Similar ratios were detected in the experimentally infected cattle. The dominance of IgG2 was independent of breed, sex, and age. Twenty-nine cattle had significant immunoglobulin levels to both C. psittaci and Coxiella (C.) burnetii simultaneously. The predominance of C. psittaci-specific IgG2, in contrast to the predominance of C. burnetti-specific IgG1 detected in these same individual serum samples under identical conditions, indicates that the ability to preferentially produce either IgG1 or IgG2 was not limited in these individual cattle. A transient yet significant IgG1 response was also developed in cows following chlamydia-induced abortions (immunotype 1) or in cattle infected with the polyarthritis-serositis-encephalomyelitis agents (immunotype 2). IgG1 levels decreased faster than IgG2 levels. These findings have diagnostic implications and identify the need for determining the immunoglobulin classes and subclasses of the humoral immune responses of animals and man to chlamydial infections.

Abortion, Veterinary↗
PubMed1987

Analysis of caprine IgG1 and IgG2 subclass responses to Chlamydia psittaci infection and vaccination.

Enzyme-linked immunosorbent assays (ELISAs) specific for caprine IgG(H+L), IgG1 and IgG2 were developed and evaluated for serodiagnosis of Chlamydia psittaci infections in a Tunisian goat flock with currently occurring chlamydial abortions and a clinically inapparent goat flock of an animal research facility. Additionally, ELISAs were applied to record the IgG1 and IgG2 dynamics of four goats vaccinated with inactivated Chlamydia psittaci and Coxiella burnetii. For screening purposes, the IgG(H+L) ELISA proved to be superior to the complement fixation test because it detected a larger number of chlamydial abortions and was easier to perform and to interpret. Analysis of Chlamydia psittaci-specific IgG1 and IgG2 responses to naturally occurring infections by ELISA revealed high IgG1 levels associated with IgG2 in goats with current abortions, whereas clinically inapparent, but seropositive goats were characterized by significantly lower IgG1 levels only (P less than 0.001). Similarly, the four vaccinated goats responded initially with Chlamydia psittaci-specific IgG1, whereas second and third vaccinations induced (as in goats with chlamydial abortions) predominantly IgG1, but also IgG2. The results indicated that clinically inapparent chlamydial infection may be distinguished from overt disease by analysing specific IgG1 and IgG2 responses. Applying Coxiella burnetii- specific ELISAs on field samples, IgG1 alone could be detected in eight, IgG2 alone in one and IgG1 combined with IgG2 in nine goats. The coxiella-specific antibody response of the four vaccinated goats was--in contrast to the chlamydia-specific response--characterized by IgG2 dominance.

Abortion, Veterinary↗
PubMed1987

Specific interaction of bovine IgG1 and IgG2 subclasses with different chlamydial antigens.

Antigens of the immunotype 1 strain B-577 of Chlamydia psittaci, which were separated by SDS-PAGE and electrophoretically transferred to nitrocellulose membranes were used to probe sequential serum samples of cattle with experimentally induced or naturally occurring chlamydial infections. Applying IgG1- and IgG2-specific markers in an enzyme immunoassay procedure, a predominance of IgG2 reactions with different proteins was determined. The interaction of IgG1 with antigens such as the genus-specific lipopolysaccharide and the major outer membrane protein was usually limited to periods immediately following overt clinical disease. Some other antigens like the 60,000 and 62,000 D proteins, for example, were recognized by both subclasses over the entire period of investigation. This indicates that it may be possible to determine the phase of infection through analysis of the IgG1 and IgG2 responses with the Western blot technique. The different IgG1 and IgG2 responses of cattle infected with different strains of Chlamydia psittaci as well as the diverse reactions of cattle from different herds with naturally occurring chlamydial infections further indicate that it may be feasible to distinguish the strains causing these chlamydial infections using different antigens in the Western blot technique. The results obtained by this method may have implications for the production of a subunit vaccine as well as for serodiagnostic purposes.

Animals↗
PubMed1987

Epidemiology and significance of Q fever in the Federal Republic of Germany.

In the Federal Republic of Germany no large Q fever epidemics (more than 200 cases) have been encountered within the last 20 years; however, Q fever was prevalent throughout that period on a constant level (between 27 and 100 officially reported cases per year). Besides classical pneumonic Q fever, chronic forms associated with endocarditis, myocarditis and hepatitis were recently diagnosed for the first time in the Federal Republic of Germany. The disease Q fever in humans is often misdiagnosed as common cold or influenza, and more attention should be paid to this entity by the medical profession. Within ten years there has been a sharp increase of Q fever infections in livestock and pets as proved by seroepidemiologic investigations. Preliminary results of a seroepidemiological study indicate a parallel increase of seropositives in the human population, but further investigations on larger numbers of sera are required for statistic confirmation. There are reasons to believe that, in contrast to general opinion, in the Federal Republic of Germany C. burnetii is involved now in infertility in cattle, and besides being a zoonosis Q fever must be considered as a potentially important infectious disease of cattle causing economic losses in this country. Further investigations on this matter are required.

Animals↗
PubMed1987

Serodiagnosis of Q fever by enzyme-linked immunosorbent assay (ELISA).

Indirect enzyme-linked immunosorbent assays (ELISAs) specific for IgG and IgM antibodies against Coxiella burnetii were applied to test 208 serum samples collected within 1983 to 1986 from 128 individuals suspected of having Q fever, and from 1611 serum samples of normal blood donors. Among them were 2 patients with Q fever endocarditis, one patient with myocarditis, one patient with chronic hepatitis, 3 patients with pneumonia, one woman who had aborted a monstrous child, 38 state veterinarians, 26 farms workers, 21 persons employed in veterinary medicine, and 4 laboratory workers. Comparison with the complement fixation test (CF) revealed 46 (38%) subjects seropositive by CF and 77 (60%) seropositive by IgG and/or IgM ELISA. Among the normal blood donors 22% had antibodies to C. burnetii by ELISA. With exception of two CF titers of 1:2 and 1:8, all positive results detected by CF were confirmed by ELISA. Early stages of C. burnetii infections could be diagnosed in four cases with a single serum sample through demonstration of specific IgM by ELISA before appearance of CF antibodies. In 9 patients with acute Q fever and rising CF titers or IgG levels, diagnosis was already possible with the first serum sample by demonstration of high IgM levels by ELISA. In the two cases of endocarditis investigated, high CF titers against phase I antigen of C. burnetii confirmed the diagnosis "chronic Q fever".

Antibodies, Bacterial↗
PubMed1987

Detection of Coxiella burnetii by the immunoperoxidase technique.

An immunoperoxidase method using Coxiella (C.) burnetii-specific hyperimmune serum raised in rabbits, and swine anti-rabbit horseradish peroxidase conjugate was applied to visualize C. burnetii in BGM cell cultures. The technique proved to be highly specific and did not result in any unspecific background staining. The technique was applied successfully to study the organism during multiplication in vacuoles of epithelial cells and in the phagolysosomes of macrophages. Preliminary results further indicate that the technique may be useful for the detection of the pathogen in tissues and milk samples.

Animals↗
PubMed1987

Q fever vaccines for animals.

The results of different workgroups and those obtained in own investigations with Q fever vaccines for cattle and sheep are reviewed and discussed. In field trials Coxiella (C.) burnetii vaccines of inactivated whole cells (WC) in phase (ph) I as well as WC ph II vaccines prevented infections of cows exposed to naturally infected environments, provided they were vaccinated as noninfected calves. To monitor calves for this purpose the sensitive ELISA has superseded the complement fixation test (CF). WC ph I vaccines failed to prevent shedding by uninfected cattle and sheep which were vaccinated and subsequently challenged by parenteral inoculation with viable organisms, but reduced shedding, and prevented pathological lesions and clinical symptoms. The results obtained in field trials with a commercially available vaccine consisting of killed WC ph II of C. burnetii and inactivated WC of Chlamydia psittaci indicated that vaccination had significantly improved fertility in vaccinated herds. However, the mechanism of protection is unclear because the function of the chlamydial component in this vaccine is not yet defined. Cattle given this vaccine can be distinguished from naturally infected cattle because the former produce predominantly non-complement-binding IgG2, detectable by ELISA. This vaccine frequently causes undesirable local reactions. Antigens of C. burnetii (strain "Frankfurt", ph II) prepared by propagation in cell cultures and successive purification by guanidinium hydrochloride- and chloroform/methanol-extraction (CMR), as well as a major protein extracted from these CMR preparations represent potential vaccine candidates without such side effects.

Animals↗
PubMed1987

Isolation of a protein antigen from Coxiella burnetii.

Antigens prepared from Coxiella burnetti, strain Frankfurt, phase II, propagated in persistently infected Buffalo Green Monkey (BGM) cell cultures were purified by guanidinium hydrochloride treatment and chloroform/methanol extraction. By ELISA analysis, chloroform/methanol residues (CMR) proved to be free of host cell antigens. The CMR were sensitive to trypsin, pronase E and proteinase K, as determined by absorption-kinetics of CMR suspensions at 600 nm and release of protein. Coomassie blue stained SDS polyacrylamide gels of proteinase hydrolysates from CMR revealed only a single component of apparently 27,000 D. Silver stained gels, however, showed a second component of apparently 12,000 D. In contrast, from untreated native C. burnetii a large variety of proteins, most of them protease-sensitive, were released by detergents at low temperatures, but the 27,000 D component was only solubilized at 60-100 degrees C. The 27,000 D component was obviously the major protein of CMR as well as of whole cells. Antigenicity of this 27,000 D protein could be demonstrated by agargel precipitation test, ELISA and immunoperoxidase techniques applying antisera raised against whole cells and against the extracted component. The component was also recognized in a dot immunobinding assay by sera from guinea pigs infected with cloned C. burnetii stain Nine Mile, phase I, thus indicating an important role of this antigen in C. burnetii specific immune response.

Animals↗
PubMed1987

[The cat as a possible infection source for Chlamydia psittaci keratoconjunctivitis in humans].

Acute follicular keratoconjunctivitis in a 25-year-old female patient was diagnosed as an infection with Chlamydia psittaci supposedly originating from a household cat with similar symptoms. The diagnosis was based on clinical symptoms, the appearance of Chlamydia-psittaci-specific IgM in the patient and the cat, and excluded other pathogenic agents. Chlamydiae organisms could not be isolated, probably due to prior antibiotic treatment. Two weeks of continuous treatment led to complete recovery of the patient and the cat. Other zoonotic infections of conjunctivitis in cats and keratoconjunctivitis in man caused by Chlamydia psittaci are mentioned.

Adult↗