Actinobaculum schaalii: a common cause of urinary tract infection in the elderly population. Bacteriological and clinical characteristics.

To-date only 21 clinical cases of Actinobaculum schaalii infection have been published, and A. schaalii has been considered a rare cause of urinary tract infection (UTI) and urosepsis. Between y 2005 and 2008, we isolated A. schaalii from 55 predisposed elderly patients. In these cases, microscopic findings of coccoid rods in wet smears of urine gave rise to clinical suspicion and subsequently to its isolation from urine. Typically only scant growth of A. schaalii occurred after incubation of the urine for 24 h, but it became visible after 2 days of incubation in 5% CO(2). Preliminary biochemical identification was carried out by combining the API Coryne and Rapid ID32A test systems, and the identification was later confirmed by partial 16S rDNA gene sequencing. During the 4-y period, A. schaalii caused septicaemia, UTIs and asymptomatic bacteriuria. One patient was later infected with Actinobaculum massiliense. The incidence of A. schaalii infections is much higher than previously reported. We present numerous case reports and describe the bacteriological and clinical characteristics of this overlooked uropathogen.

Denitrobacterium detoxificans gen. nov., sp. nov., a ruminal bacterium that respires on nitrocompounds.

A new group of anaerobic, Gram-positive, high G + C (56-60 mol%) bacteria was isolated from the bovine rumen. Of four strains characterized, all were non-motile and none produced spores. The isolates did not produce indole or H2S and did not hydrolyse gelatin. Cells of each strain exhibited similar rod-shaped morphology (0.5-1.0 x 1.0-1.5 microns) although bulbous ends were sometimes present. None of the four strains were able to grow via oxidation of a variety of potentially fermentable substrates but rather obtained energy for growth via anaerobic respiration processes, oxidizing hydrogen, formate or lactate for reduction of various oxidized nitrogen compounds. Trimethylamine oxide and DMSO were also used as electron acceptor. All four strains shared greater than 99% 16S rRNA gene sequence identity. The closest match found between the 16S rRNA gene sequence of all four strains, NPOH1T, NPOH2, NPOH3 and MAJ1, to sequences available in GenBank was that of Coriobacterium glomerans (86% sequence similarity), a phenotypically dissimilar anaerobe within the class Actinobacteria. To accommodate these bacteria the creation of a new genus and species, Denitrobacterium detoxificans, for placement within the family Coriobacteriaceae is proposed. The type strain, NPOH1T (ATCC 700546T), grew equally well over a narrow range of incubation temperatures tested (32-39 degrees C).

Biotypes of Arcanobacterium haemolyticum.

Colony morphology, beta hemolysis on horse blood agar, beta-glucuronidase activity, and ability to ferment sucrose and/or trehalose defined two biotypes of Arcanobacterium haemolyticum. One, the smooth type, grew as smooth, beta-hemolytic colonies and was beta-glucuronidase negative but often fermented sucrose and/or trehalose, while the other, the rough type, grew as rough colonies and was nonhemolytic, beta-glucuronidase positive, and negative for sucrose and trehalose fermentation. About 75% of the A. haemolyticum strains studied (n = 138) were of the smooth type. The smooth type predominated in wound infections, while the rough type was isolated almost exclusively from respiratory tract specimens; thus, 84% of the smooth-type strains were derived from wounds and 91% of the rough-type strains were isolated from respiratory tracts.

Branched Escherichia coli cells.

We report that the normally rod-shaped bacterium Escherichia coli can form branched cells. These were found in strains in which chromosome replication or nucleoid segregation was disturbed, e.g. in minB mutants, intR1 strains, and in strains exhibiting stable DNA replication. Often chromosome DNA was found to be located in the branch point of the cells. The branching frequency was dependent upon the growth medium: in rich medium no branched cells were found, whereas in minimal medium containing acetate and casamino acids the frequency of branched cells was increased. The genetic background of the strains also affected the tendency to branch. Furthermore, electron microscopy of thin-sectioned branched cells revealed additional membrane-like structures, which were not observed in wild-type cells. Finally, the branched cells are compared with bacteria that normally branch, and probable causes for branching in E. coli are discussed.

Ageing-associated thiol loss in Bacterionema matruchotii.

This work tested the concept that thiol loss, proposed as a cause of animal ageing, occurs in ageing cultures of Bacterionema matruchotii. Paired comparisons were made between thiol levels of exponential- and stationary-phase cultures. Values for stationary phase were consistently and significantly (P less than 0.01) lower. If bacterial thiol loss is an effect of culture ageing rather than a cause, the same possibility must be considered with respect to tissue. However, if thiol loss is a cause of ageing, the role for thiol loss in tissue ageing would be strengthened. A major problem in the biology of ageing is to distinguish between cause and consequence. Bacterial culture could provide a relatively simple model for such inquiry.

Incidence of actinomycetes infection in women using intrauterine contraceptive devices.

Pancervicovaginal smears taken from 350 women using an intrauterine contraceptive device (IUD) were screened for the presence of actinomycetes organisms. Of the 12 cases in which actinomycetes-like organisms were seen in Papanicolaou-stained smears, the presence of actinomycetes organisms was confirmed by immunofluorescence in 10 cases. The prevalence of actinomycetes infection was thus 2.8% (10 of 350 cases) in the IUD users. Eight (4.3%) of 173 symptomatic subjects had actinomycetes infections. Two of the positive cases were asymptomatic. Eight of the ten patients with confirmed actinomycetes infection were using the Cu T device while two were wearing the Lippes Loop IUD. Seven of the ten patients had been using an IUD for more than two years. The time of insertion of the IUD (postpuerperal, postmenstrual or after medical termination of pregnancy) did not show any correlation with the presence of actinomycetes infection. Actinomyces israelii was responsible for the infection in eight cases while Arachnia propionica was seen in two cases. The organisms could not be grown in culture.

[Bifidobacterium flora status of cosmonauts before and after completing space flights]. / Sostoianie bifidoflory u kosmonavtov do i posle osushchestvlenie kosmicheskikh poletov.

The state of bifidoflora was examined in eight cosmonauts before and after space flights of varying duration. Prelaunch quantity of bifidobacteria decreased drastically. In space flights of 30 days and longer the level of acid formation by bifidobacteria was reduced. The species composition of bifidoflora remained stable. The most typical intestinal species of bifidobacteria were B. Longum and B. adolescentis.

Demonstration of Actinomyces and Arachnia species in cervicovaginal smears by direct staining with species-specific fluorescent-antibody conjugate.

For direct observation of microaerophilic actinomycetes by fluorescent antibody, a procedure was developed in which pepsin treatment and rhodamine conjugate of normal serum were used to reduce nonspecific staining in cervicovaginal smears. Actinomyces israelii, Actinomyces naeslundii, and Arachnia propionica were observed in cervicovaginal smears from women who did use and who did not use an intrauterine contraceptive device. A. israelii was found more commonly in women with an intrauterine contraceptive device, but no evidence was obtained that the use of an intrauterine contraceptive device influenced the presence of either A. propionica or A. naeslundii.

PIP: A procedure was developed for the direct observation of microaerophilic actinomycetes by fluorescent antibody. In the procedure pepsin treatment and rhodamine conjugate of normal serum were used to reduce nonspecific staining in cervicovaginal smears. Observations of "A. israelli," "A. naeslundii." and "A. propionica" in cervicovaginal smears are reported. These organisms were identified by direct staining with flurescein isothiocyanate (FITC)-labeled rabbit globulin specific for each organism and by observing for a typical actinomycete morphology. In initial experiments with FITC conjugates, "A. israelli" could not be demonstrated in tissue sections known to be positive by culture and Gram stain. By using the conjugates specific for each species, examination of the sections of endometrium and endocervix showed actinomycotic filaments staining only with the anti-"A. israelli" conjugate. Examination of cervicovaginal smears from the first 25 patients with phase-control microscopy were not suitable for observations of actinomycete elements. Of the smears from the 19 patients with an IUD, 39% were postive for "A. israelli," and 17% were positive for "A. propionica." None of the smears was positive for "A. naeslundii." Only 12% and 6% of the slides from 32 patients without an IUD stained positively for "A. israelli" and "A. naeslundii," respectively.

Quantitative in vitro assay for "corncob" formation.

The interaction of Bacterionema matruchotii with strains of Streptococcus sanguis produces a structure which morphologically resembles a corncob. To determine the specific bacterial surface receptors involved in the interaction, we developed a quantitative assay. The assay consisted of mixing saline suspensions of [CH(3)-(3)H]thymidine-labeled streptococci and B. matruchotii, incubating at 37 degrees C for 2 h, and filtering the mixture through a 5-mum polycarbonate membrane filter. The free cocci and filaments passed through the filter, but the corncobs were retained. Estimates of the number of corncobs formed were obtained by quantitating the radioactivity retained on the membranes relative to that of controls of streptococci alone. Although saturation of the Bacterionema occurred at a ratio of streptococci to Bacterionema of 10:1 (Klett units), a 2:1 ratio was chosen because of the increased sensitivity of the assay at this ratio. The percentage of streptococci binding at this ratio was 18.6 +/- 8.1 (standard deviation). All five Bacterionema strains tested formed corncobs; in contrast, only three strains of S. sanguis were positive. These were serotype 1 strains which had localized surface "fuzz." Although scanning electron microscopic observations revealed an almost random distribution of cocci along the filament surface, transmission electron microscopy revealed that the streptococci were attached to the Bacterionema by the surface fuzz. No differences in corncob formation were observed in sodium phosphate buffer, pH 6 to 8, at phosphate concentrations ranging from 0.005 to 0.05 M. Concentrations of NaCl or KCl up to 0.25 M did not affect corncob formation, and low concentrations of CaCl(2) increased corncob formation slightly, whereas MgCl(2), ethylenediaminetetraacetic acid, and citrate buffers reduced the number of streptococci binding to the filaments. These results suggest that divalent cations may play a role in this process.

Anaerobic, gram-positive, pleomorphic rods in human gingival crevice.

Sixty-two strains of anaerobic, gram-positive, pleomorphic rods were isolated from the gingival crevice of individuals clinically free from peridontal disease, and examined for biochemical characteristics, cellular and colonial morphology, and acid end-products from glucose fermentation. None of them produced indole, hydrogen sulfide, or catalase, but all hydrolysed esculin. Seven, 10 and 45 of 62 strains were identified as Bifidobacterium, Actinomyces naeslundii, and Actinomyces israelii, respectively, on the basis of biochemical characteristics.

[Morphology of the bifidobacteria by light and electron microscopy and their biological properties]. / Morfologiia bifidobakterii na svetoopticheskom i élektronno-mikroskopicheskom urovne i ikh biologicheskie svoistva.

The morphology and the acid-producing, antagonistic and enzymatic activity of the strains of bifidobacteria isolated from the intestine of adults and children were studied. Bifidobacteria showed a considerable polymorphism, all the strains were antagonistically active. The strains isolated from adults were found to have greater acid-producing activity; the predominant species were B. longum and B. adolescentis, and in children B. bifidum were also isolated. The characteristic feature of B. longum strains was the presence of a slime-like layer and formations resembling bubbles around bacterial cells. The stains with greater physiological activity were found to have an extensive mesosomal complex, as well as a great number of volutin granules.

Experimental formation of "corn cob" in vitro.

Organisms isolated from corn cob were examined for aggregation with Bacterionema matruchotti. Such aggregations, interpreted as corn cob formation, in vitro, occurred with five isolated identified as Streptococcus sanguis. A cell-surface component of Streptococcus sanguis or a phospholipid-related substance of Bacterionema matruchotii appeared to be involved.

A medium for the isolation and enumeration of oral actinomycetaceae from dental plaque.

A supplemented, infusion-based medium that supports the growth of most oral Actinomycetaceae is described. The inclusion of Naf and colistin sulfate enabled actinomyces to be isolated from dental plaque in the presence of few other oral microorganisms.