Acta pathologica et microbiologica Scandinavica. Section B, Microbiology最新文献

Two tumors induced by BK virus in hamsters of an inbred strain were serially transplanted by subcutaneous injection of tumor explants. Both the original tumors as well as the transplants grew as solid, localized, encapsulated tumors. Histologically tumors were classified as fusocellular fibrosarcomas. Polymorphic tumor tissue was by an abundance of collagen fibers and multinucleated giant cells. Cell lines established from tumors contained nuclear T antigen which stained with sera from a number of tumor-carrying hamsters, but also with SV40 T antiserum. Viron antigens were not detected in these cell lines, and no virus was isolated when tumor extracts were inoculated in Vero cells.

The co-agglutination technique, utilizing antibody coated protein A-containing staphylococci, was successfully adapted to grouping N. meningitidis strains. It was found to give more clear-cut results than the standard slide test, especially in the case of strains isolated from throat specimens. The co-agglutination technique has also other advantages over the standard slide test in the grouping of meningococci: minor influence by auto-agglutination, higher specificity, easy performance and low consumption of specific antisera. Preliminary results also showed that the co-agglutination technique could be applied for the rapid detection of meningococcal antigen in cerebrospinal fluid.

Two hundred and seven urinary strains of staphylococci and micrococci were classified biochemically according to Baird-Parker (1963) and by means of a simplified schema. One hundred and thirteen strains belonged to Staphylococcus aureus, S. epidermids or S. saprophyticus (64 strains) according to the simplified schema, respectively to Baird-Parker's sub-groups SI, SII or M3. S. saprophyticus was isolated from young, female out-patients, was relatively resistant to novobiocin and contained poly AbetaC (beta-N-acetylglucosaminyl ribitol teichoic acid and beta-N-acetylglucosaminyl glycerol teichoic acid). S. aureus and S. epidermidis were isolated from older, male in-patients, were sensitive to novobiocin and contained poly A (N-acetylglucosaminyl ribitol teichoic acid), respectively poly B (glucosyl glycerol teichoic acid). Ninety-four strains belonging to other Staphylococcus or Micrococcus subgroups could not be classified by the simplified schema. With few exceptions, these strains were sensitive to novobiocin and either gave a precipitin reaction corresponding to poly C or were non-typable with the teichoic acid reference systems used. The simplified schema is recommended for the classification of coagulase-negative strains of Micrococcaceae.

A computer-based numerical approach to the allocation of Pseudomonas aeruginosa bacteriphage patterns has been presented. This rendered a usefule identification of similar phage types. The grouping had epidemiological relevance. Grouping of phage typing patterns of P. aeruginosa by numerical analysis showed that the patterns of related isolations may differ in one strong lysotype reaction, occasionally even in more reactions. Thus parallels previous findings which have been based on studies of the reproducibility of the method and evaluations of differences in epidemiologically related strains from the same sources.

During the recent decade, 1651 isolates of Staphylococcus aureus from 111 patients with cystic fibrosis have been tested for antibiotic sensitivity and half of the isolates have been phage typed. All the patients were followed in one clinic and the policy of antibiotic treatment was consistent during this period. The results show a dynamic situation where "epidemic" phage types during recent years have been gradually replaced by other types and, during the same period, the prevalence of strains resistant to more than one antibiotic decreased. Multiresistant strains including strains resistant to methicillin were infrequent in these patients. From 23 per cent of the patients, the same strains were repeatedly isolated for more than 1 year despite an apparently successful chemotherapy. Recently isolated strains were found to produce cellbound as well as extracellular protein A. Ninety-one per cent of the strains produced extracellular lipase and only 8 per cent were resistant to mercury chloride. Eighty-one per cent of the patients produced precipitating antibodies agains S. aureus as judged by crossed immunoelectrophoresis. The investigated properties of S. aureus were not significantly correlated with the occurrence of precipitating antibodies against these bacteria. The possible significance of protein A in the pathology of the respiratory tract infection is discussed.

Previously published reports have established a correlation between twitching motility and the possession of polar fimbriae in all cases examined. Twitching motility was shown to be highly dependent on the availability of liquid at the agar surface. In the present paper experiments are reported that establish: 1) the dependence of twitching on the existence of a layer of liquid of a particular thickness, 2) the production of such a liquid layer surrounding areas of growing organisms, and 3) the affinity of twitching bacteria for the air-water interface. Reasoning from these facts, it is postulated that the demonstrated affinity for the air-water interface is conferred upon the cells by the polar fimbriae. It is also suggested how the movements might be generated.

Microbial surface growth on routine opaque agar media was examined by various incident light microscopical techniques. Only differential interference contrast regularly gave good resolution and contrast. The arrangement of units approaching the size of individual bacteria may be judged by low power dry objectives.

The influence of therapeutic concentrations of phenylbutazone on human granulocyte function has been examined using a method which facilitates a precise in vitro evaluation of the phagocytic and bactericidal activities of polymorphonuclear leucocytes. Phenylbutazone caused a marked reduction in intracellular killing of bacteria by the granulocytes. Whether this inhibition of granulocyte function also takes place in vivo resulting in enhanced susceptibility to infection, remains unknown.

Cells of Treponema genitalis were studied in the electron microscope by means of negative staining and ultrathin sectioning techniques. All cells were covered by a regularly structured surface layer. This layer appeared to consist of pairs of thin fibrils attached to an amorphous layer. This amorphous layer in turn is probably identical with the exterior part of the outer membrane of the organism. The pairs of thin fibrils located on this surface were interconnected by polygons. The treponemes were regularly coiled and had somewhat tapered ends with 2-4 flagella inserted at each end. The two bundles of flagella were entwined around the cytoplasmic body of the cell and interdigitated in the middle region of the organism. Treatment of cells of T. genitalis with Myxobacter AL-1 protease 1, or with deoxycholate did not reveal intracytoplasmic tubules. This is in contrast to the results obtained with similar treatments of all other strains of species of Treponema hitherto examined.

The effect of beta-propiolactone (BPL) on the infectivity and haemagglutinating properties of BK virus was studied. No virus multiplication was observed when Vero cell cultures were inoculated with virus treated with 0.1 per cent or higher concentration of BPL. On the other hand, treatment of BK virus with 0.1 per cent or lower concentration of BPL had no apparent effect on viral haemagglutinin. BPL at a concentration of 0.1 per cent could therefore be used to prepare BK virus haemagglutinin which contains little or no infectious virus. Inactivated haemagglutinin seems to be somewhat labile against freezing and thawing, but storage at 4 degrees C had no effect on it. Identical haemagglutination inhibiting antibody titres were obtained when human sera were tested with standard haemagglutinin or with haemagglutinin inactivated with BPL.