Zentralblatt für Bakteriologie. 1. Abt. Originale A, Medizinische Mikrobiologie, Infektionskrankheiten und Parasitologie最新文献

Various species of Clostridium, Bacteroides, Propionibacterium and Eubacterium were incubated in a 1% solution of 1,2-0-iso-propylidene-D-glucofuranose in a peptone-yeast-extract (PY) medium according to the VPI-technique. The volatile and non volatile acids were investigated by gas-liquid chromatography. All microorganisms showed a pattern of VFA different from that one produced by the glucose containing medium. In most microorganisms the formation of acetic acid was suppressed while the production of propionic, butyric, valeric and iso-valeric acids was stimulated. The production of succinic acid was not affected. Simultaneous determination of monoacetone glucose and glucose in the culture medium showed that the glucose analogue is used to a lesser extent than glucose.

Verschiedene Arten von Clostridium, Bacteroides, Propionibacterium und Eubacterium wurden mit einer 1%igen Lösung von 1,2-0-iso-Propyliden-D-Glukofuranose („Monoaceton-Glukose“) in einer Pepton-Hefe-Extrakt (PY) enthaltenden Nährlösung, gemäß der VPI-Vorschriften, bebrütet. Die flüchtigen sowie die nicht flüchtigen Säuren wurden gas-chromatographisch untersucht. Die Chromatogramme dieser Mikroorganismen zeigten flüchtige Fettsäuren in anderen Verhältnissen als jene der in einer Glukose enthaltenden Nährlösung gezüchteten Mikroorganismen. Bei den meisten Mikroorganismen war die Bildung von Essigsäure unterdrückt, während die Produktion von höheren flüchtigen Fettsäuren erhöht war. Die Bildung von Bernsteinsäure wurde nicht beeinflußt. Eine gleichzeitige Bestimmung von Monoaceton-Glukose und Glukose in den inkubierten Nährlösungen zeigte, daß Monoaceton-Glukose nicht so stark wie Glukose abgebaut wird.

Thymidine levels in urines from 14 patients suffering from severe chronic urinary tract infection were determined microbiologically. The concentrations found were < 10 ng/ml to 33 ng/ml and these do not seem to be any different from the concentrations determined in healthy persons. Results from growth kinetic experiments support the assumption of low thymidine levels in the urines of these patients and in most cases trimethoprim or co-trimoxazole were seen to act in a bactericidal manner in these urine samples. Various aspects of the role of exogenous and endogenous thymidine for the activity and bactericidal effect of trimethoprim, sulfonamides and their combinations, their mutual synergism, the importance of thymine auxotrophs, the problem of thymidine availability and its role in testing media are discussed.

Isolation of colonies with altered colonial morphology was frequently observed following infection of specific pathogen-free rats fed a caries-inducing high sucrose diet with two human strains of Streptococcus salivarius. These isolates produced unique rough colonies on mitis salivarius agar, in contrast to the smooth, mucoid colonial morphology of the parental strain. The rough variants were characterized by a marked increase in the synthesis of polysaccharide from sucrose, especially cell-associated water-insoluble glucan, whereas the smooth parental strains mainly produced cell-free fructan. Glucose-grown cells of rough variants but not smooth parental strains were aggregated upon addition of sucrose. Such variants were not detected during laboratory transfers of the human strains of S. sali- varius nor by mutagenesis of the cultures.

Von spezifiziert pathogenfreien Ratten, die ein saccharosereiches, kariesinduzierendes Futter erhielten und mehrfach mit zwei humanen Streptococcus salivarius-Stämmen infiziert worden sind, ließen sich häufig Kolonien mit einer veränderten Morphologie isolieren. Diese Isolate bildeten ausgeprägte rauhe Kolonien auf Mitis-Salivarius-Agar im Gegensatz zu den glatten, mukoiden Kolonien des Ausgangsstammes. Die Rauhformen waren durch eine gesteigerte Polysaccharidsynthese gekennzeichnet, besonders von zellgebundenem wasserunlöslichem Glukan. Die Glattformen bildeten dagegen vorwiegend zellfreies Fruktan. In glukosehaltigen Medien gezüchtete Zellen der Rauformen wurden durch Zusatz von Saccharose aggregiert; bei den glatten Elternstämmen wurde diese Erscheinung dagegen nicht beobachtet. Derartige Varianten wurden weder nach mehrjährigen Überimpfungen im Laboratorium noch durch Mutagenese der Kulturen gefunden.

The growth promoting properties of seven commercially manufactured and two recently developed culture media are compared according to a standardized method. The study is carried out alternately without and with the addition of 10% fresh human blood to the culture media. The carefully selected test strains include 20 species of bacteria and 2 species of yeasts which represent obligatory aerobic, facultative anaerobic and obligatory anaerobic microorganisms with quite different nutritional and atmospherical requirements.

The 9 tested media are good enough for the purpose of culturing nonfastidious bacteria. However, most of the commercially prepared media failed to detect small inocula of very fastidious microbial agents, especially when no blood is added. Collectively, thiol broth is the most noneffective medium. The last but one is thioglycollate medium. Three culture media based on brain heart infusion formula prove to be effective. Those are the commercial brain heart dextrose and the two media recently developed by the authors, namely brain heart dipeptone (BHD) and brain heart dipeptone cysteine (BHDC). BHD is the most suitable medium for the detection of obligatory aerobic and facultative anaerobic fastidious microorganisms. BHDC detects anaerobic fastidious bacteria quite effectively. The other media, namely Columbia, trypticase soy, trypticase soy sucrose, and Rosenow are of limited value with regard to the detection of small inocula of fastidious microorganisms. The causes of the unsatisfactory results with different commercial media are discussed in detail. The authors point out to the possible use of hypertonic media in special cases. Properties that should be fulfilled by blood culture media are proposed.

After abortion sera were taken from 58 thoroughbred and other mares of the north- western part of Germany and investigated by ELISA (enzyme linked immuno-sorbent assay) for antibodies against Mycoplasma equirhinis, M. subdolum, M. equigenitalium, M. pulmonis, M. felis, Acholeplasma laidlawii, A. hippikon, and A. equifetale. Reactions at serum dilutions of 1:32 and higher were considered as positive. At serum dilution 1:32 no antibodies were found in 11 sera. The remaining sera showed antibodies against one or more of the mycoplasma antigens investigated. The number of multiple reactions decreased with an increasing dilution of the sera. Titers were found between 1:32 and 1:256. In one case a titer of 1:2048 against M. equigenitalium antigen was found. Most often antibodies against A.laidlawii were observed, i.e. in 37 sera. These antibodies also showed the highest titers. Only 3 sera contained antibodies against A. hippikon. Antibodies against M. felis and A. equifetale were found in 26 sera. Between 10 and 15 sera showed antibodies against the remaining mycoplasma species.

Egg-grown and L cell-grown C. psittaci 6BC strains formed two bands when centrifuged through preformed Renografin gradients. No additional bands were observed by extending the time of centrifugation. Particles present in the bands which were collected from the Renografin gradients were examined by electron microscopy. Purified elementary bodies from both egg- and L cell-grown sources were located in a lower, minor band; egg-derived elementary bodies showed a higher density (p < 0.01) than elementary bodies derived from L cells. Particles present in the major, upper band of both egg- and L cell-derived strains had similar densities and contained mixed populations of elementary bodies and polymorphic reticulate bodies.