Helmut Brunner

Determination of IgG, IgM, and IgA antibodies toMycoplasma pneumoniae by an indirect staphylococcal radioimmunoassay

An indirect staphylococcal radioimmunoassay (SRIA) has been developed for determination ofM. pneumoniae antibodies. This test allows the detection of antibodies in various immunoglobulin (Ig) classes similar to the previously described radioimmunoprecipitation test (RIP). SRIA has two advantages over RIP: first, it uses 100-fold less anti-Ig reagents than RIP; second, bound can be separated from unbound antigen more easily by the relatively heavy staphylococci. SRIA antibodies, belonging to the IgA class of Ig, could be detected in nasal secretions of volunteers infected intranasally with ts H43 ofM. pneumoniae. In sera of patients withM. pneumoniae pneumonia antibodies to the IgG or the IgM class of Igs could be determined separately. This is especially important for an early diagnosis ofM. pneumoniae disease.

A staphylococcal radioimmunoassay for detection of antibodies toMycoplasma pneumoniae

A radioimmunoassay (RIA) which depends on the property of protein A ofStaphylococcus aureus to combine with the Fc-fragment of immunoglobulins was developed.This technique was employed to measure antibodies in human and various animal sera. It could be demonstrated that the staphylococcal RIA was at least as sensitive as the previously described radioimmunoprecipitation technique in detecting antibodies toM.pneumoniae in human sera. In addition, antibodies toM.pneumoniae could be demonstrated in sera of hamsters intranasally inoculated with the organisms. Antibodies could also be demonstrated in rabbit sera after immunization withM.pneumoniae. The test proved to be considerably more sensitive than conventional tests for detection of antibodies to the organisms. The test requires only small amounts of reagents and is relatively inexpensive.

Cytochemical localization of surface carbohydrates on mycoplasma membranes

Surface carbohydrate structures, containinga-D-glucosyl or sterically closely related residues, were visualized on mycoplasma membranes by a cytochemical staining procedure with concanavalin A and iron-dextran complexes.

Response of guinea pigs and hamsters to experimental infection withMycoplasma pneumoniae

SummaryIn an effort to further delineate the mechanism of infection and pathogenicity ofMycoplasma pneumoniae infections, the hamster and guinea pigs were used as experimental models. These animals were chosen because of previous experience. The local antibody response in addition to organism growth patterns were examined in detail. Histological examination was carried out to determine the pathological lesions which occur. The significance of these findings is discussed.ZusammenfassungUm die Wirkungsweise einer Infektion und die Pathogenität vonMycoplasma-pneumoniae-Infektionen weiter zu erforschen, wurden tierexperimentelle Untersuchungen mit Hamstern und Meerschweinchen durchgeführt. Diese Tiere wurden auf Grund früherer Erfahrungen ausgewählt. Die lokale Antikörperreaktion wurde neben dem Wachstumsverhalten des Erregers gründlich untersucht. Zur Bestimmung der auftretenden pathologischen Veränderungen wurden histologische Untersuchungen vorgenommen. In dem Referat wird die Bedeutung dieser Befunde diskutiert.RésuméDans le but de mieux définir le mécanisme dinfection et la pathogénicité deM. pneumoniae, le hamster et le cochon dInde ont été utilisés comme modèles expérimentaux. Ces animaux ont été choisis en fonction de lexpérience passée. La réponse locale aux anticorps a été examinée en détail, de même que les modes de croissance des micro-organismes. Lexamen histologique a eu pour but de déterminer la nature des lésions constatées. Limportance de ces constatations fait lobjet dune discussion.ResumenEn un esfuerzo por delimitar más el mecanismo de infección y la patogenicidad de las infecciones porM. pneumoniae, se utilizaron hamsters y conejillos de Indias como modelos experimentales. Se escogieron estos animales debido a las experiencias previas con los mismos. Se examinó detalladamente la respuesta local de anticuerpos además de los patrones de crecimiento del organismo. Se llevó a cabo un examen histológico para determinar las lesiones patológicas que pudieran aparecer. Se discute la significación de estos hallazgos.SamenvattingTeneinde het infectiemechanisme en de pathogeniciteit vanM. pneumoniae infecties verder te kunnen afbakenen werden de hamster en het Guinese biggetje gebruikt als experimenteel model. Vroegere ervaringen leidden tot de keus van deze dieren. De locale antilichaam produktie en de groeipatronen van de organismen werden nauwkeurig onderzocht. Histologisch onderzoek werd uitgevoerd teneinde de pathologische lesies, die voorkomen vast te stellen. De betekenis van de bevindingen wordt besproken.RiassuntoNel tentativo di studiare maggiormente il meccanismo dellinfezione e la patogenicità delle infezioni daM. pneumoniae si impiegarono come modeli sperimentalli lhamster e la cavia, scelti in base a precedenti sperimentazioni. Venne particolarmente studiata la risposta anticorpale locale e la modalità di sviluppo del microorganismo. Per stabilire il tipo di lesione si praticarono esami istologici. Viene discusso il significato di questi dati.

Einfluß von Antibiotika auf die Phagozytose von Klebsiella pneumoniae durch Alveolarmakrophagen

Abstract The effect of gentamicin and cephalotin on the phagocytosis of Klebsiella pneumoniae by alveolar macrophages of guinea pigs was tested. At their minimal bactericidal concentration (MBC) the antibiotics did not influence the uptake of bacteria by macrophages in the presence of various antibody titers. As expected, the number of surviving bacteria after intracellular ingestion decreased at MBC of the antibiotics. The uptake of bacteria was inhibited by very high concentrations of gentamicin and cephalotin only. The intracellular killing of the bacteria was already higher in the presence of relatively low antibiotic concentrations (one third of the minimal inhibitory concentration, MIC) as compared to the killing without antibiotics. Above this levels, even if they were considerably higher than the MIC, the antibiotics had no additional effect on the number of bacteria surviving after ingestion. These findings indicate that concentrations above one third of the MIC of gentamicin or cephalotin are not necessarily of advantage for the effect of macrophages on the bacteria, provided that sufficient levels of antibodies are also present.

Seroepidemiologische Untersuchungen zum Vorkommen von Chlamydien-Antikörpern beim Menschen

1,075 serum samples taken at random from blood donors and 524 samples from patients were investigated with a group-specific antigen for chlamydial antibodies. Antibodies were detected in 9.9% of the blood donors and in 25.7% of the patients, with titers from 1:5 to 1:160 in the former group and up to 1:640 in the latter group. In general, patients had significantly higher titers than blood donors. More attention should therefore be paid to the possible role of Chlamydia in infections of unknown origin.Zusammenfassung1075 Serumproben von Blutspendern und 524 von Patienten wurden mittels der Komplementbindungsreaktion unter Verwendung eines gruppenspezifischen Antigens auf Chalmydien-Antikörper untersucht. Der Prozentsatz der Positivreagenten betrug bei Blutspendern 9,9%, bei erkrankten Personen 25,7%. Die Titerwerte lagen bei Blutspendern zwischen 1 : 5 und 1 : 160, bei Patienten wurden Werte bis 1 : 640 ermittelt. Die prozentuale Titerverteilung unter den Positivreagenten verlagerte sich bei der Gruppe der Erkrankten in Richtung höherer Titer. Eine stärkere Beachtung einer möglichen Beteiligung von Chlamydien bei Infektionen unklarer Genese ist erforderlich.Summary1,075 serum samples taken at random from blood donors and 524 samples from patients were investigated with a group-specific antigen for chlamydial antibodies. Antibodies were detected in 9.9% of the blood donors and in 25.7% of the patients, with titers from 1 : 5 to 1 : 160 in the former group and up to 1 : 640 in the latter group. In general, patients had significantly higher titers than blood donors. More attention should therefore be paid to the possible role of Chlamydia in infections of unknown origin.

Enzym-immuno-assay bei Listeriose: Antikörper- und Antigennachweis — Vorläufige mitteilung1

Abstract An enzyme-immuno-assay (EIA) was developed for the determination of antibodies to Listeria monocytogenes O- and H-antiger.s of serotypes 1 and 4 b, which are predominant in the Federal Republic of Germany. The results correlated well with the tube agglutination but the titers in EIA were considerably higher. Thus one advantage of the EIA was its sensitivity. In addition, the EIA offers the possibility to detect antibodies belonging to different immunoglobulin classes. The EIA is easy to perform and requires smaller amounts of reagents than the tube agglutination. Since optical densitys is determined in the EIA, the data obtained in this system are less variable than the tube agglutination which is read by eye. The method proved also to be useful for the detection of Listeria-Antigen. Approximately 0.3 μ g/ml of H-antigen could still be detected in the EIA. Since the serological diagnosis of Listeria-infections is hampered by the cross-reactions to various other bacterial antigens the detection of Listeria-antigen by a sensitive immunological procedure could be of considerable value. This is especially the case when culture procedures are not promising, e.g. during or after antimicrobial chemotherapy.

Giant Cell Formation in Acholeplasma laidlawii, Strain JA1

Striking alterations, which looked like blebs, were observed in colonies of Acholeplasma laidlawii, strain JA 1. Craters were seen on the surface of these colonies by scanning electron microscopy. In addition, giant cells of acholeplasma, up to 14 microns in diameter, i.e. approximately 20 times the size of a normal A. laidlawii cell, were visible in the colonies. The large forms were surrounded by a unit membrane. After infection with group 1 and group 2 mycoplasma-viruses, the proportion of altered colonies and the number of large cells within these colonies increased. A strain of A. laidlawii, which was not susceptible to infection with the three known acholeplasma-viruses did not exhibit comparable morphological changes. The development of the giant cells can be explained either by cell fusion or by a lag of cell division behind genome replication. Blebs and craters may result from the destruction of mycoplasma organisms within the complex structure of the colony. There is also suggestive evidence that strain JA 1 carries a virus in some cryptic form.