Bacterial surface protein L binds and inactivates neutrophil proteins S100A8/A9.

Finegoldia magna is an anaerobic bacterial species that is part of the normal human flora on all nonsterile body surfaces, but it is also a significant opportunistic pathogen causing a wide range of infections. Some isolates of F. magna that are more frequently associated with clinical infection express protein L, a surface protein containing multiple homologous domains (B1-B5) that bind Igs through interactions with Ig L chains. The present study shows that the N-terminal A domain of protein L binds S100A8/A9, antibacterial proteins present in large amounts in the cytoplasm of neutrophils, but also extracellularly in tissues during inflammation. As a result, protein L-expressing F. magna are protected against killing by S100A8/A9. Igs and S100A8/A9 were found to interact independently with protein L, demonstrating that this bacterial surface protein is capable of manipulating both adaptive and innate immune defense mechanisms.

[Association of acquired polyagglutinabilities of types T and B. An observation]. / Association des polyagglutinabilités de types T et B acquis. A propos d'une observation.

Although T and acquired B polyagglutinabilities are not exceptional, simultaneous occurence of the two types is a rarer phenomenon. Ten days after an open heart surgery operation, the patient, age 55, had an infectious syndrom : two strains, Clostridium perfringens and Peptococcus variabilis were isolated. Simultaneously, her red cells were found to be polyagglutinable. The association of T and acquired B polyagglutinabilities could be demonstrated by serological studies of the patient's red cells, and by in vitro transformation of normal red cells using culture supernatants obtained from the two isolated strains.

Infection of total hip prostheses by Peptococcus magnus: an immunofluorescence and ELISA study of two cases.

In two cases of infected total hip replacements, Peptococcus magnus was isolated in pure culture from the implant when it was removed. Fluorescent antibody and ELISA studies have shown that both patients developed an antibody response to this anaerobic coccus soon after the replacement operation. These results suggest that the organism is a true infective agent, which was probably responsible for the failure of the arthroplasty operation.

Differentiation of several isolates of Peptococcus magnus by counterimmunoelectrophoresis.

Uniform sonicated suspensions of three clinical isolates of Peptococcus magnus that were morphologically, chromatographically, and biochemically identical were used to produce hyperimmune antisera in rabbits. Similar hyperimmune serum was prepared to a single strain of Peptostreptococcus anaerobius. When these antisera and antigens were tested by counterimmunoelectrophoresis, the three isolates of Peptococcus magnus were immunologically distinct. None of the antisera to Peptococcus magnus formed precipitin lines with Peptostreptococcus anaerobius.

[The serological behaviour of the pyogenic anaerobes, Peptococcus asaccharolyticus and P. prevotii (author's transl)]. / Das serologische Verhalten der pyogenen Anaerobier Peptococcus asaccharolyticus und P. prevotii

Using rabbit antisera against whole-cell adjuvant-free antigens, the serological behaviour of ten butyrate-producing Peptococcus strains, five belonging to P. asaccharolyticus and five to P. prevotii, was studied in cross-agglutination and gel-diffusion experiments. Agglutination occurred in all the homologous and nearly one third of the heterologous antigen-antibody systems. Cross-reactions, however, were clearly restricted to members of the same Peptococcus species.

Fluorescent antibody study of the gram-positive anaerobic cocci.

Fluorescent antibody conjugates were prepared from five species of anaerobic cocci commonly isolated from human infections. When tested with homologous and heterologous cells these conjugates were found to be highly specific. There was no evidence of a common genus antigen. Peptococcus magnus conjugates detected a species-specific antigen; cross-reactions with Peptostreptococcus anaerobius were readily eliminated by absorption. The conjugates from Peptococcus asaccharolyticus, Peptococcus prevotii, Peptostreptococcus, anaerobius, and Peptostreptococcus intermedius displayed a high degree of strain specificity. Occasional cross-reactions were detected with homologous strains, suggesting the presence of common antigens, but no attempt was made to determine the number of different serotypes in these species.