[Demonstration of iron transport activity in Pasteurella multocida cultures]. / Nachweis von Eisen-Transport-Aktivität in Pasteurella multocida-Kulturen.

It has been established that Pasteurella multocida cultures possess pronounced iron transport activities to accumulate the iron necessary for growth. Experiments with Fe-59 confirmed that the bacterial cells are able to acquire iron without direct contact from high molecular iron substrates, such as iron dextrane, ferritine or transferrine. Microbial siderophores of the hydroxamate and phenolate types, such as desferrioxamin B and enterobactine as well as other iron chelators (phenanthroline, citrate and nitrilotriacetate) decrease the bacterial cell growth or iron incorporation and are not relevant for iron transport in P. multocida. The direct analytical identification of siderophores using the reactions by Csaky (hydroxamate type) and Arnow (phenolate type) has proved unsuccessful. The importance of the mannan cell wall polysaccharide is discussed with respect to the iron transport. Thus in terms of iron accumulation, P. multocida is similar to Yersinia, which also possess an efficient transport system for iron not involving siderophores.

[Effect of iron on Pasteurella multocida]. / Einfluss von Eisen auf Pasteurella multocida.

Iron is an important factor for growth, virulence and immunogenicity of the species Pasteurella multocida. This has been demonstrated in numerous experiments with bacterial cultures in vitro and immunized and not immunized animals in vivo (mice, piglets, calves). Iron substrates or iron chelators affect in different manner the virulence of P. multocida in vivo, depending on chemical character of the given compounds, their dose, route and time of application, and also depending on the host. P. multocida has an up to time unknown iron transport system, which can acquire the essential iron from physiological substances, such as heme, ferritine, transferrine, lactoferrine etc. This conclusion results from in vitro experiments with growing cultures, with insertion of radioactive iron (Fe-59) from different sources, and with iron solubilization in neutral pH ranges. In the same way, the iron of iron dextran and low molecular iron compounds is available for P. multocida. Iron of unphysiological complexes, potassium ferrocyanide, and ferrocene is unavailable. On the other side such iron chelating agents as nitrilotriacetate, tirone, ferrocene, citrate, EDTA, and apotransferrine do not or only a little affect growth, and such chelators as alpha, alpha'-dipyridyle, phenanthroline and the microbial siderophores deferrioxamin B and enterobactin are inhibitory substances for multiplication of P. multocida. This substances also inhibit the insertion of Fe-59 into the bacterial cell. The conclusion is drawn that neither enterobactin nor deferrioxamine B as typical representatives of phenolate or hydroxamate siderophores take part in Fe-transport of P. multocida.

[Modification of virulence and immunogenicity of Pasteurella multocida by iron in vitro]. / Beeinflussung von Virulenz und Immunogenität bei Pasteurella multocida durch Eisen in vitro.

The virulence of Pasteurella multocida strains in experimental infections of mice has been shown to depend on the iron contents of the cultivation media. Frequent passages of bacteria on iron-deficient growth media result in drastic decrease of virulence. In the case of one strain also immunogenicity was lowered. The results with nutritional media differing in their iron contents show that iron probably exhibits a regulatory effect on the production of a not yet identified virulence.

[Utilization of L-aspartate, L-malate and fumarate by Pasteurella multocida]. / Verwertung von L-Aspartat, L-Malat und Fumarat durch Pasteurella multocida.

Strains of Pasteurella multocida use L-aspartate, L-malate and furmarate, respectively, as substrates for production of succinic acid which accumulates in the medium. As was established by studies with 14C and 3H labelled substrates, the degradation of these substances proceeds analogous via the citric acid cycle.

[Characterization of structural elements in lipopolysaccharides of Pasteurella multocida]. / Charakterisierung von Strukturelementen in den Lipopolysacchariden von Pasteurella multocida.

In the main fraction of oligosaccharides obtained after the acetic acid hydrolysis of the lipopolysaccharides of the strain PM were identified: terminal bound glucose and L-glycero-D-manno-heptose, 1,2-,1,3,4-, and 1,3,4,6,-linked heptose. The oligosaccharide of the strain 1297 S contains terminal linked galactose, 1,4- or 1,6-linked glucose and 1,4-linked N-acetylglucosamine additionally. The molar ratios of these elements show the heterogenicity of the preparations. The determined molecular weights underline the R-character of the LPS. In the by-fractions of the acetic acid hydrolysis the known mannan and another polysaccharide with galactose and glucosamine were identified.

[Problems in using radioactively labeled bacteria in animal experiments. 4. Distribution of activities in the mouse following intratracheal administration of labeled Pasteurella multocida]. / Probleme des Einsatzes radioaktiv markierter Bakterien bei Tierversuchen. 4. Mitteilung: Aktivitätsverteilung im Müseorganismus nach intratrachealer Verabreichung von markeierten Pasteurella-multocida-Keimen.

Intratracheal administration of 3H-labelled, 14C-labelled, 59Fe-labelled or 125J-Labelled Pasteurella multicida germs to mice resulted in more or less differentiated, nuclide-dependent, distributions of radioactivity in blood, spleen, liver, lung, kidney, and gastro-intestinal tract. All distributions were comparable to those following subcutaneous application. Elimination of antigen from lungs and other organs could be characterised by an e-function, once a certain level of distribution had been reached. Some of the antigen was persistent in the lung not less than 14 days. Extremely high activity concentration and persistence was recordable, following the use of 59Fe complete antigen. Phagocytosis of Pasteurella multicida germs through alveolar macrophages of the lung was secured by autoradiography. Most of the antigen seemed to be discharged from the lungs through the digestive tract. Antigen distributions recorded from immunised and non-immunised mice seemed to suggest that the fate of antigen applied was affected by the kind of immunisation. No difference in antigen distribution between non-immunised and subcutaneously immunised animals were recordable, following intratracheal antigen application, but is was clearly recordable, following intratracheal immunisation. Elimination of antigen from the lungs of intratracheally immunised animals was found to occur faster than it did from non-immunised animals.

[Further characterization of lipopolysaccharides from Pasteurella multocida]. / Weitere Charakterisierung der Lipopolysaccharide aus Pasteurella multocida.

The biological properties, sedimentation behaviour, and electron-optically visualised structures of lipopolysaccharides from Pasteurella multocida were found to be identical with lipopolysaccharides from Enterobacteriaceae. Hard evidence to the effect that lipopolysaccharides from Pasteurella multocida are R-lipopolysaccharides were produced by the composition of monosaccharides together with experiments on the basis of disc electrophoresis.