bluuebunny/crossref_metadata_2025 huggingface dataset:
Purification of proteins similar to HPr and enzyme I from the oral bacterium Streptococcus salivarius. Biochemical and immunochemical properties
Authors: Vadeboncoeur Christian , Proulx Mario , Trahan Luc
Published: May 2010

The phosphoenolpyruvate:sugar phosphotransferase system (PTS) is made of several proteins. Two of them are designated general proteins because they are required for the transport and phosphorylation of all sugars of the PTS. These two proteins are found in the soluble fraction of cellular extracts and are termed HPr and enzyme I (EI). We reported in this work the purification and the characterization of these two proteins from Streptococcus salivarius ATCC 25975. HPr was purified by DEAE-cellulose chromatography, molecular sieving on Ultrogel AcA44, and carboxymethylcellulose chromatography. Sodium dodecyl sulfate electrophoresis in the presence of urea revealed a single band with a molecular weight of 6700. The protein contained no tryptophan and had a pi of 4.8. The purification scheme of EI was as follows: DEAE-cellulose chromatography, hydroxylapatite chromatography, DEAE-Sephadex A-50 chromatography, preparative electrophoresis, and molecular sieving on Ultrogel AcA34. The five-step purification for EI produced a 199-fold purified preparation with a specific activity of 530 μmol of HPr phosphorylated per minute per milligram of protein at 37 °C. The fraction obtained after filtration on Ultrogel AcA34 gave one band (68 000) on sodium dodecyl sulfate – polyacrylamide gel electrophoresis. The molecular weight of the native enzyme determined by gel filtration at 4 °C was 135 000, suggesting that it was a dimer. Enzyme I had a pI of 4.2, a pH optimum of 6.7, a Km for HPr of about 27 μM, a Km for phosphoenolpyruvate of 0.48 mM, and kinetics that were consistent with a Ping-Pong mechanism. Evidence had been obtained which indicated that S. salivarius enzyme I was antigenically very similar to enzyme I from various strains of Streptococcus mutans, but not to the enzyme from Bacillus subtilis, Staphylococcus aureus, Streptococcus faecalis, and Escherichia coli.
Attachment of Salmonella to mammalian cells in vitro
Authors: Mintz Clifford S. , Cliver Dean O. , Deibel R. H.
Published: May 2010

The attachment of Salmonella typhimurium strain PHL67342 to several mammalian tissue culture cell lines was investigated. Strain PHL67342 failed to attach in significant numbers to the Buffalo green monkey (BGM), swine testicular (ST), and HeLa cell lines. Significant attachment was observed with the Henle intestinal cell line. Log-phase cells of strain PHL67342 attached in greatest numbers to the Henle cells after 45 min of incubation at 37 °C. Attachment to the Henle cells was not affected by D-mannose or D-galactose, but was markedly inhibited by high concentrations of alpha-methyl-D-mannoside. Also, Salmonella lipopolysaccharide had no effect on the attachment of strain PHL67342 to the Henle cells. Fimbriae were not detected on the bacterial cells used in the adherence experiments. These results suggest that some bacterial factor(s) other than fimbriae and lipopolysaccharide mediate the attachment of strain PHL67342 to the Henle cells.
Comparative pathogenicity of auxotrophic mutants of Candida albicans
Authors: Manning Marcia , Snoddy Christina B. , Fromtling Robert. A.
Published: May 2010

An induced mutant of Candida albicans with greatly decreased virulence for mice is described. The mutant was one of five auxotrophic mutants obtained by ultraviolet irradiation of a clinical isolate (strain MY 1044). The five mutants included two methionine auxotrophs, one methionine–cysteine auxotroph, one temperature-sensitive serine auxotroph, and one auxotroph with unknown growth requirements. Each of the mutants produced normal mycelium and had a normal profile of susceptibility to four antifungal drugs. The virulence of each mutant was compared with the parent strain by LD50 determination in mice. Four of the five auxotrophs exhibited LD50's that were not significantly different from the parent strain (mean LD50 = 7.5 × 105 cells). However, the temperature-sensitive serine auxotroph was significantly less virulent than the parent strain (LD50 > 107 cells), even though it grew well in vivo and in mouse serum at 37 °C in vitro. Use of this mutant in conjunction with its "isogenic" parent should help to elucidate true virulence factors in C. albicans.
Penicillin sensitivity of nodulation in soybean roots
Authors: Takats S. T.
Published: May 2010

Penicillin was administered to the primary roots of soybean (Glycine max. L. Merr) at the time of inoculation with Rhizobium japonicum and at various times after inoculation. Penicillin reduces nodule yield and shifts the frequency distribution of nodules along the primary roots. When administered at the time of inoculation, the earliest nodules do not form; when administered at later times, from 10 to 72 h after inoculation, the later nodules are reduced in number. These effects, when related to parallel effects of penicillin on bacterial viability, peptidoglycan synthesis, and binding to the roots suggest that penicillin interferes with more than one stage of nodule induction.
Characterization of anti-Citrobacter 036 specific polysaccharide monoclonal antibodies
Authors: Shearman P. J. , Bundle D. R. , Romanowska E. , Lugowski C. , Bogulska M.
Published: May 2010

Monoclonal mouse antibodies specific for the 0 antigen of Citrobacter 036, a homopolymer of β(1 → 2)-linked 4-deoxy-D-arabinohexose, were generated by the hybridoma technique. Balb/c mice were immunized with killed whole-cell vaccine and initial selection of active clones was based on enzyme-linked immunosorbent assay (ELISA) employing purified lipopolysaccharide (LPS). Concentrated culture supernatants from selected hybrid cultures were used to identify 10 0-antigen specific monoclonal antibodies using the multiple criteria of immunoprecipitation of 0 chains and LPS, inhibition by acid hydrolyzed 0 chains in the screening ELISA, and antibody class analysis. Four monoclonal antibodies were chosen for further study using dose-dependent 0-chain inhibition of ELISA and passive hemagglutination, passive hemolysis, and bacterial agglutination titres. When screened with Citrobacter serotypes known to contain the sugar 4-deoxy-D-arabinose, passive hemagglutination tests showed that the two monoclonal antibodies examined possessed titres which could be correlated with the reported 4-deoxy-D-arabinohexose content of the respective LPS's. This sugar is an antigenically important unit of several Citrobacter serotypes as defined by these well-characterized monoclonal antibodies.
The microcyst wall of Didymium iridis: chemical analyses
Authors: Raub Thomas J.
Published: May 2010

Chemical analyses of the microcyst cell wall of Didymium iridis were done to compare it with other well-studied organisms, Physarum polycephalum and Physarum flavicomum. Large wall fragments were obtained by breakage in a Braun homogenizer. Chemical analyses of purified walls identified neutral sugars, protein, and hexosamine as the major components. Wall polysaccharides were mostly composed of galactosamine with smaller amounts of glucose and galactose. The protein component consisted of large quantities of threonine and aspartate–asparagine with trace amounts of the sulfur-containing amino acids. Most of the wall protein was soluble in alkaline urea. Sodium dodecyl sulfate – polyacrylamide gel electrophoresis was used to identify seven major bands, at least four of which are acidic glycoproteins. Most of the galactosamine was associated with the urea – hot alkali insoluble fraction comprised mostly of glucose. This galactosaminoglucan was partially sulfated and acetylated and arranged as microfibrils that maintain cell shape.
Indigenous microfloras and resistance to bacterial infection in mice with experimentally induced diabetes: a possible animal model for opportunistic infection
Authors: Imai Akihiro , Morishita Keiko , Kurihara Yoko
Published: May 2010

Persistent diabetes was induced in male Slc: ddY mice by a single intraperitoneal injection of 200 mg/kg streptozotocin (STZ). In these mice, the numbers of aerobic gram-negative bacilli, staphylococci (including micrococci), and streptococci increased, while those of other bacteria were almost unchanged in both oral and caecal floras. The mice were vulnerable to oral infection of Salmonella enteritidis, intranasal infection of Klebsiella pneumoniae and Serratia marcescens, and contact infection with mice infected with S. enteritidis and K. pneumoniae. These findings suggest that STZ-treated mice might be a useful model for investigating opportunistic infection.
Le transport de la phénylalanine et de la tyrosine chez Brevibacterium linens : spécificité et incorporation dans les protéines
Authors: Boyaval P. , Moreira Evelyne , Desmazeaud M. J.
Published: May 2010

The specificity of phenylalanine and tyrosine carriers was investigated using actively metabolizing cells of Brevibacterium linens. The cellular protein synthesis of resting cells was very weakly inhibited, even with high concentrations of chloramphenicol or tetracycline. The nonaromatic amino acids were weak inhibitors for these carriers, while fluorinated analogues of phenylalanine and tyrosine were very potent competitive inhibitors. In practice these analogues cannot be used to replace amino acids to evaluate transport without incorporation because they are incorporated in cellular proteins.
Antibodies to Rickettsia rickettsii in Peromyscus leucopus from a focus of Rocky Mountain spotted fever in Connecticut
Authors: Magnarelli Louis A. , Anderson John F. , Burgdorfer Willy , Philip Robert N. , Chappell W. Adrian
Published: May 2010

During 1980–1982, white-footed mice (Peromyscus leucopus) were captured in Newtown, Connecticut, an area where Rickettsia rickettsii, the etiologic agent of Rocky Mountain spotted fever, is thought to be enzootic. An indirect micro-immunofluorescence test identified specific antibodies to this organism in 16 of 237 (7%) sera; titration end points for 14 samples were relatively high (1:128–1:2048). Antibodies were detected in mice during 1980 and 1981 with monthly prevalences varying from 8 to 22%. These results suggest that P. leucopus may be involved in the ecology of R. rickettsii and that these rodents can be included along with other mammals to monitor spotted fever rickettsial infections in nature.
Rhizobium meliloti Tn5 induced auxotrophic mutants responding to different biosynthetic intermediates
Authors: Ali Hassan , Béchet Max , Niel Christian , Guillaume Jean-Bernard
Published: May 2010

Using a suicide plasmid as a vector, the kanamycin–neomycin resistance conferring transposon Tn5 was introduced into the genome of the two Rhizobium meliloti strains 444 and M28str. Among clones carrying random Tn5 insertions, about 0.3% auxotrophic mutants were isolated from each strain. Tn5 was found to integrate preferentially into genes involved in syntheses of adenine, arginine, leucine, pyrimidines, sulphur-containing amino acids, and tryptophan. Growth responses to biosynthetic intermediates uncovered four and two groups of methionine- and tryptophan-requiring mutants, respectively.
Factors affecting the bacterial colonization of various surfaces in a river
Authors: Baker J. H.
Published: May 2010

The colonization rates of substrates, differing in their surface charge and asperity, have been determined in a temperate river. Glass, which has a high surface charge, was colonized by the natural bacterial population just as fast as polystyrene with a low surface charge. However, roughening the surface of either substrate greatly increased the rate of bacterial colonization. On the roughened surfaces bacteria did not selectively colonize cavities or grooves and current velocity was not an important factor. It is suggested that different sections of the naturally occurring bacterial population are the initial colonizers of different types of surface.
Reversion of mutations in the thymidine kinase gene in herpes simplex viruses resistant to phosphonoacetate
Authors: Campione-Piccardo J. , Rawls W. E.
Published: May 2010

Mutations in the DNA polymerase locus of phage, bacteria, and eukaryotic cells may change the mutation rates at other loci of the genome. We used resistance to phosphonoacetate to select mutants of herpes simplex virus with mutated DNA polymerase and then determined the reversion frequency of viral thymidine kinase mutation in mutants and recombinants. The results obtained indicate that mutations causing resistance to phosphonoacetate do not affect the mutation rate of the viral genes. This finding is consistent with the existence of two functional regions in the DNA polymerase molecule, one involving the pyrophosphate acceptor site and responsible for resistance to phosphonoacetate and another involved in the editing ability and recognition specificity of the enzyme.
Degradation of lignocellulose in wheat straw versus hardwood by Cyathus and related species (Nidulariaceae)
Authors: Wicklow D. T. , Langie R. , Crabtree S. , Detroy R. W.
Published: May 2010

Twelve species of Cyathus and two additional taxa included in the Nidulariaceae (i.e., Crucibulum laeve (Bull. ex DC) Kambly and Nidula niveo-tomentosa (Henn.) Lloyd) were examined for their ability to differentially modify the lignin and cellulose components of wheat (Triticum aestivum L.) straw (WS) and a silver maple (Acer saccharinum L.) hardwood (HW) log. Our results indicate that the rate and pattern of biological modification of native lignocellulose differs according to substrate and fungal species chosen for the fermentation. The ecological specialization or substrate preferences of the species selected for study was not always an accurate predictor of how each fungus ranked in its ability to degrade WS or HW.
Evaluation of D-xylose fermenting yeasts for utilization of a wood-derived hemicellulose hydrolysate
Authors: Fein Jared E. , Tallim S. Radig , Lawford G. Ross
Published: May 2010

Seven of 37 strains of yeast, recently identified for their ability to ferment D-xylose to ethanol, produced this alcohol from crude hardwood hemicellulose hydrolysate in batch culture, with variable amounts of xylitol as a by-product. Of these, Candida tropicalis showed the greatest potential for ethanol production. The crude acid hydrolysate was found to be inhibitory to all of the yeasts, even at dilute hydrolysate concentrations. Significant improvements in the utilization of the substrate were achieved through both strain acclimatization and chemical pretreatment of the hydrolysate.
Bacillus mycoides phages and their satellites
Authors: Tikhonenko Anna S. , Belyaeva Nina N. , Kretova Anna F.
Published: May 2010

The relationship between large and small particles of phages No. 1M and H17 reproducing simultaneously in one and the same bacterial cell of Bacillus mycoides was studied by the immune electron microscopic technique. The large particles of phages No. 1M and H17 were morphologically identical with phage No. 1 of B. mycoides, whereas only the tails of small particles of phages No. 1M and H17 were morphologically identical with the tail of phage No. 1. Antigens were identified in phages No. 1, No. 1M, and H17 using specific antibodies against phage No. 1, containing only large phage particles, and specific antibodies against phage H17 small heads. It was shown that (i) all structural elements of large particles and tails of small particles of phage No. 1M were antigenically identical with those of phage No. 1; (ii) all structural elements of small and large particles of phage H17, except the inner core of the tail, were antigenically different from phage No. 1; and (iii) the small heads of phages No. 1M and H17 were antigenically identical. Particles of phage No. 1 are morphologically and antigenically identical with the large particles of phage No. 1M and are antigenically different from the large particles of phage H17. Since the tails of small and large particles are antigenically identical in each phage pair (No. 1M and H17), this suggests that in both cases, the genome of a small defective phage codes for the synthesis of head proteins only, whereas its tail is borrowed from the corresponding helper phage. The small phage may therefore be considered as a satellite of the large phage which depends on a helper partner for production of complete particles and whose tail proteins are identical with those of the helper phage.
Effect of the fumigant metham on Trichoderma spp.
Authors: Lewis J. A. , Papavizas G. C.
Published: May 2010

Radial growth of 34 isolates of Trichoderma hamatum, T. harzianum, and T. viride was inhibited (mean effective dose (ED50)) by as little as 1.3 μg of vapors (mostly methylisothiocyanate) per cubic centimeter of atmosphere from metham decomposing in soil suspensions. Isolates of T. hamatum were generally more sensitive than those of T. harzianum to the vapors. Spore germination was more sensitive than hyphal growth to vapors, and whereas the toxic volatiles were only fungistatic to growth, they were fungicidal to germination. As little as 0.5 μg/cm3 of vapors from decomposing metham in soil reduced germination of conidia of three isolates (TMP, Tm-1, and T-1-R4) more than 50% and in another three (T-1, Th-6, and Th-20) 90%. Exposure of spores to metham in solution (350 μg active ingredient/mL) for 1 h reduced survival more than 50% in eight isolates. When conidia of T. viride (T-1-R4) and T. harzianum (WT-6-24) were added (ca. 20 × 103 spores/g) to soil treated with a sublabel rate of metham (equivalent to 234 L/ha), the number of colony-forming units (CFU) of isolates introduced 4 days before, or at time of fumigation were significantly less than those in nonfumigated soil after 3 weeks of incubation. CFU of isolates introduced 4 days after fumigation were similar to those in nonfumigated soils. Over a 9-week period, introduced populations of T-1-R4 and WT-6-24 remained static in nonfumigated soils. Indigenous Trichoderma spp. appeared unaffected by the levels of metham used. Addition of bran or use of soils high in natural organic matter did not affect results.
Impact of an oil field effluent on microbial activities in a Wyoming river
Authors: Heitkamp Michael A. , Johnson B. Thomas
Published: May 2010

The survival, functions, and physiological diversity of autochthonous sediment microbiota were examined in situ at five stations along the Little Popo Agie River, WY; one station above, one at, and three below a discharge point for oil wastewater from Union Oil Company's Dallas Field. Below the oil wastewater discharge point there were increases in electron-transport activity, carbon dioxide production, and microbial populations of heterotrophs, ammonifiers, hexadecane degraders, starch hydrolyzers, protein hydrolyzers, and sulfate reducers. At a station 1420 m below the discharge point, however, overall sediment microbial activities and all of the physiological groups of bacteria, except hexadecane-degrading microbiota, were at levels comparable with those at the control station above the discharge point. Similarly, mineralization of glucose, amino acids, hexanoic acid, and hexadecane was elevated at stations directly below the discharge point, but appeared to subside rapidly. Xenobiotic biodegradation potential of the sediments varied with the chemical and the sample location and was not directly related to oil residue levels in the sediment. Microorganisms thus appeared to maintain physiological diversity and increased in numbers and activity in a riverine environment that contained petroleum hydrocarbon concentrations known to be deleterious to freshwater fish and macrobenthic communities.
Seasonal study of a freshwater lake and migratory waterfowl for Campylobacter jejuni
Authors: Hill G. A. , Grimes D. J.
Published: May 2010

In the summer and fall of 1981, water and sediment samples form Lake Onalaska, a Mississippi River navigation pool near La Crosse, Wisconsin, were quantitatively examined for Campylobacter jejuni and for standard bacterial indicators of fecal pollution. Fifty cecal content samples, representing seven species of transient waterfowl captured during fall migration, were also assayed for C. jejuni. Fecal coliform and fecal streptococcus counts from the water and sediment samples agreed with previously established values for the pool and accurately reflected the influx of approximately 619 000 ducks and geese during fall migration. Campylobacter jejuni was not recovered from water, sediment, or cecal samples. This conflicts with previous reports which implied a cosmopolitan distribution of C. jejuni among waterfowl. Reasons for the absence of C. jejuni from the pool and from waterfowl in and around that pool were discussed, with special reference to method of recovery and sporadic distribution of other pathogenic microorganisms among migratory waterfowl.
Interaction of Clostridium difficile toxin A with L cells in culture
Authors: Shahrabadi M. S. , Bryan L. E. , Lee P. W. K.
Published: May 2010

Toxin A of Clostridium difficile was purified by column chromatography and acetic acid precipitation. Cells exposed to toxin A showed polarization of nuclei towards one pole of the cells. Toxin A was conjugated to ferritin and applied to L cells to localize binding sites of this toxin to the cell surface. It was found that toxin A conjugate attached to the cell membrane in aggregated form. Antibody specific to toxin A was prepared and used for localization of intracellular toxins in intoxicated cells. Toxin A was found inside the cytoplasm 6 h after cell treatment, mainly in the form of aggregates inside the cytoplasmic vacuoles. At 24 h after exposure, toxin A could be detected within the cytoplasm. Tunicamycin treatment of cells reduced the cell-binding efficiency of toxin A to 50%, but neuraminidase did not effect toxin binding significantly.
Cells from newborn rat brain established in primary tissue culture will support rubella virus replication
Authors: Alstyne Diane Van , Smyrnis Elie M. , Singh Vijendra K.
Published: May 2010

We have initiated an in vitro study comparing the susceptibility of newborn and adult animals to rubella virus (RV) associated encephalitis. Glial cells from injured adult rat brain (RG cells) have been established in continuous culture and these cells were reported to restrict RV replication. When RG cells were infected, no infectious progeny virus particles were detected in tissue culture media and only five intracellular viral polypeptides could be detected using immune precipitation techniques (p75, p60, VP44, VP41, and VP19). Two polypeptides normally associated with a productive infection, VP24 and p30, could not be detected. In this report we have applied these techniques to an investigation of RV replication in newborn brain cells and have shown that relatively normal yields of all seven polypeptides found in RV-infected cells could be detected. These data indicate that some glia from newborn brain in primary culture are permissive for RV replication unlike the restricting RG cells and that this difference in restriction is critical in determining the outcome of their infection by RV.
Evidence for involvement of pyrH+ of an Escherichia coli K-12 F-prime factor in inhibiting construction of hybrid merodiploids with Salmonella typhimurium
Authors: Kelln Rod A.
Published: May 2010

Transconjugants were not recovered in matings between Salmonella typhimurium and Escherichia coli K-12 strains carrying the chromosomal region between leu and argF on an F-prime factor, even when a restriction-deficient recipient was used. A mutant F-prime factor compatible for transfer to S. typhimurium was constructed by transposon mutagenesis and characterized as being deficient in directing the synthesis of UMP kinase (encoded by pyrH). Other compatible F-prime factors were readily constructed by employing a procedure designed to select for strains carrying F-prime factors harboring pyrH mutations.
Triggering in unactivated Bacillus megaterium spores
Authors: Thibeault Doris , Lefebvre Gerald M.
Published: May 2010

The kinetics of triggering in unactivated spores of Bacillus megaterium ATCC 14581 were studied over a wide range of concentrations of the germinant β-D-glucose. At all but the lowest glucose concentration investigated, the rate of triggering decreased continuously on increasing duration of exposure to the germinant, this decrease being faster than exponential. Our results suggest that both triggering and its inhibition are alternative outcomes of the interaction of the germinant with the spores. At sufficiently dilute glucose concentrations the triggering curve is sigmoidal with unactivated spores, but is exponential if the spores have been previously heat shocked. In the absence of an initial lag interval on triggering, the observed decrease in the sample lag time by either heat activation or on increasing the glucose concentration in unactivated spores makes it necessary to consider that the effects of these two forms of stimulation are not limited to the triggering event.
Adsorption of tumorigenic Agrobacterium tumefaciens cells to susceptible potato tuber tissues
Authors: Pueppke Steven G. , Benny Ulla K.
Published: May 2010

Cells of tumorigenic Agrobacterium tumefaciens strain B6 were labeled with [35S]methionine and used to estimate bacterial adsorption to potato tuber discs. After 10 min at pH 7.2, about 5 × 105 bacteria adsorb to each 9.0-mm disc. Lengthening the incubation period to 90 min increases adsorption to about 11 × 105 bacteria per disc. Bacterial adsorption is reduced under both alkaline and acid pH conditions and increases 2.3-fold if the number of bacterial cells in the inoculum is doubled. Adsorption is increased if citrus pectin, polygalacturonic acid, or demethylated pectin is included in the inoculum; methylated polygalacturonic acid is inactive. The activity of citrus pectin is abolished, however, if the compound is applied to the discs as a pretreatment and then removed prior to inoculation. Lipopolysaccharide preparations from five of six A. tumefaciens strains have no effect on bacterial adsorption. The sixth preparation, from nontumorigenic strain NT-1, reduces adsorption by about 20%.
Nitrous oxide production from nitrification and denitrification in marine sediment at low oxygen concentrations
Authors: Jørgensen Kirsten Schannong , Jensen Hanne Beck , Sørensen Jan
Published: May 2010

Measurements of N2O production (release of free N2O), nitrification, and denitrification were made simultaneously in NH4Cl- and KNO3-amended suspensions of marine sediment. An open flow system was designed for the application of low partial pressures of O2 (0–10 kPa) to the sediment. The overall rate of N2O production increased dramatically at the lowest O2 tensions (0–0.2 kPa) and had a maximum at complete anoxia. The specific rates of N2O production from nitrification (N2On) and from denitrification (N2Od) were determined after separation of the processes with inhibitors. Within the range of 0–0.2 kPa O2, the rate of N2On production showed an apparent maximum of 0.1 kPa O2 where the production accounted for 25% of the total activity of nitrification ([Formula: see text] oxidation). The rate of N2Od production, however, continued to increase as the O2 fell to zero. The proportion of N2Od to the total N2Od plus N2 produced from denitrification increased at the higher O2 tensions and reached the maximum of about 50% at 5 kPa O2. Except for a narrow range between 0.1 and 0.2 kPa O2, denitrification was the main source of N2O at 0–10 kPa O2.
Minimal antigenic characterization of eight Rhizobium meliloti strains by indirect enzyme-linked immunosorbent assay (ELISA)
Authors: Olsen P. E. , Rice W. A.
Published: May 2010

The somatic antigens of eight Rhizobium meliloti strains were characterized by indirect enzyme-linked immunosorbent assay (ELISA) carried out in microtiter plates. Washed cells were bound by evaporation of cell suspension in plate wells at 85 °C. The antigenic characterization was based on determinations of the selective removal of antibodies from antisera against the strains by extensive reciprocal adsorptions with heterologous cells. Four of the strains were found to possess distinctive antigens and a total of seven different combinations of antigens were found among the eight strains. One pair of the strains was not distinguishable by the assay used.
Positive serological evidence that Hantaan virus, the etiologic agent of hemorrhagic fever with renal syndrome, is endemic in Canada
Authors: Lee Ho Wang , Seong In Wha , Baek Luck Ju , McLeod Donald A. , Seo Jeong Sun , Kang C. Yong
Published: May 2010

Hemorrhagic fever with renal syndrome is endemic in most parts of the world. The etiological agent in known as Hantaan virus. More than 2000 Canadian sera from all age groups and provinces were tested for the presence of antibody to this virus by the indirect immunofluorescent antibody technique. The frequency of seropositivity ranged from 0.3 to 4.0%, with the national average being 1.4%. Newfoundland and New Brunswick in the Atlantic region had the highest positivity, being higher than hyperendemic areas in Korea. The inland provinces of Ontario, Manitoba, and Alberta had only 0.5% positives to Hantaan virus. In contrast, approximately 1.5% of sera from Saskatchewan, Quebec, and British Columbia were positive. No correlation in positivity was found between geography or sex, but positivity did increase with age. The highest titres were found in the group aged 65 to 93 years.
The preference for strains of Rhizobium meliloti by cultivars of Medicago sativa grown on agar
Authors: Bromfield E. S. P.
Published: May 2010

Variation in nodulation preference within and between cultivars of Medicago sativa for Rhizobium strains was assessed under axenic conditions using inocula consisting of paired strains of R. meliloti which could be recognized by distinctive colony morphology or antibiotic resistance. The largest variability in host preference for Rhizobium strains was among plants within cultivars and not between cultivars. The implications of such variation are discussed in the context of possible enhancement of symbiotic nitrogen fixation. An isolate of R. meliloti which had been marked with antibiotic resistance and cured of a cryptic plasmid was significantly less successful in nodulation than its wild-type parent strain in all inoculated combinations. The interaction of inoculum and cultivar on yield indicated differential symbiotic effectiveness of strains of R. meliloti on cultivars of M. sativa.
Differential mechanisms for liposome uptake by vegetative and aggregation competent cells of Dictyostelium discoideum
Authors: Sekeri-Pataryas K. H. , Vakirtzi-Lemonias C.
Published: May 2010

Liposomes labelled with 125I-labelled albumin were used as carriers for the introduction of albumin into vegetative and aggregation competent cells of Dictyostelium discoideum. The subcellular distribution of albumin and its degradation products was followed. The results show that 44 and 67% of the radioactivity incorporated by vegetative and aggregation competent cells, respectively, was found in soluble form in the cell. These figures fall to 26 and 34% in the presence of metabolic inhibitors with a concomitant increase of membrane-bound radioactivity. Differences in the mode of liposome–cell interaction in the two stages of development of the organism and the possibility that metabolic inhibitors may operate at the site of the vacuole–liposome fusion step are discussed.
Porcine haemophili and actinobacilli: characterization by means of API test strips and possible taxonomic implications
Authors: O'Reilly T. , Rosendal S. , Niven D. F.
Published: May 2010

Thirty Haemophilus strains and six Actinobacillus strains, all of porcine origin, were examined for their biochemical reactivity on API 20E and API ZYM test strips using dense cell suspensions (supplemented with NAD as appropriate) as strip inocula. When combined with a test for V-factor dependency, the use of both strips allowed adequate differentiation of closely related organisms. Numerical taxonomic analysis of the data demonstrated that the majority of the haemophili and actinobacilli studied could be placed in one of four major clusters; these clusters contained, respectively, the H. pleuropneumoniae – A. pleuropneumoniae strains, the H. parasuis strains, strains belonging to Haemophilus taxon "minor group," and strains belonging to an unusual group of mannitol-positive, urease-negative haemophili. A representative of Haemophilus species taxon C and an unusual Actinobacillus isolate appeared to be comparatively unrelated to organisms in the four major clusters. Although it may, on occasion, be difficult to place an unusual isolate in any one particular group, owing to the uncertain taxonomy of some of these organisms, it is concluded that API test strips can serve as useful tools for the characterization and differentiation of porcine haemophili and actinobacilli.
Endogenous infection in mice with streptozotocin-induced diabetes. A feature of bacterial translocation
Authors: Imai Akihiro , Kurihara Yoko
Published: May 2010

Slc:ddY mice that received a single intraperitoneal injection of 200 mg/kg streptozotocin (STZ) were examined for persistency of diabetes (changes of indigenous bacterial floras, and bacterial translocation. Significant diabetes (increase in plasma glucose and decrease in insulin) was recognized 2 weeks after the injection, and persisted for 12 weeks. The numbers of aerobic gram-negative bacilli, staphylococci (including micrococci), and streptococci in caecal and oral floras were significantly increased, but the numbers of anaerobic bacteria in caecal flora were hardly changed. Bacterial translocation of indigenous bacteria to the mesenteric lymph node, lung, or kidney was detectable in some mice 2 weeks after the injection. The incidence of bacterial translocation in these STZ-treated mice then increased; infection caused by several organisms, e.g., Klebsiella pneumoniae, Staphylococcus epidermidis, streptococci, or Lactobacillus sp., occurred in lung, liver, spleen, kidneys, and mesenteric lymph node. No indigenous bacteria were cultured from these organs of control mice. This endogenous infection may have been due to the overpopulation of several bacterial strains caused by disruption of indigenous floras along with depression of immunological function.
Binding between pole bean (Phaseolus vulgaris L.) lectin and rhizobia that do or do not nodulate the pole bean
Authors: Wong Peter P. , Shantharam S.
Published: May 2010

The pole bean (Phaseolus vulgaris L. cv. Kentucky Wonder) was nodulated not only by Rhizobium phaseoli 127K14 but also by Rhizobium sp. 127E15, R. leguminosarum 92A3, and R. trifolii 0403. It was not, however, nodulated by R. trifolii ATCC 14481 and R. japonicum 61A118. The binding between pole bean lectin (PBL) and various strains of Rhizobium that can or cannot nodulate the pole bean was tested. Using rabbit antibodies prepared against purified PBL, the lectin was shown by immunofluorescence microscopy to be present on the pole bean root hair surface. The binding between PBL and exponentially growing rhizobia was quantified by a radial immunodiffusion technique. PBL was found to bind to all rhizobia tested whether they nodulate the pole bean or not. The amount of PBL bound to R. phaseoli 127K14, Rhizobium sp. 127E15,R. leguminosarum 92A3, R. trifolii 0403, R. trifolii ATCC 14481, and R. japonicum 61A118 was 3.7, 4.0, 7.4, 5.7, 7.8, and 6.5 μg per 109 cells, respectively. Although hemagglutination activity of PBL was inhibited by N-acetyl-D-galactosamine, the binding betwen PBL and rhizobia was strongly inhibited by D-gluconate, D-galacturonate, and polygalacturonate. The latter three carbohydrates did not inhibit hemagglutination. The results suggest that the sugar specificity of PBL for binding rhizobia may be different than that for the interaction with erythrocytes. Since the sugar specificities of PBL and soybean lectin for binding R. japonicum are different, rhizobia such as R. japonicum 61A118 may have multiple independent binding sites, each having different sugar specificity, for lectins of various legumes.
Morphogenesis of arthroconidiation in the dermatophyte Trichophyton mentagrophytes with special reference to wall ontogeny
Authors: Hashimoto Tadayo , Emyanitoff R. G. , Mock R. C. , Pollack J. H.
Published: May 2010

The formation of arthroconidia, especially the ontogeny of the arthroconidial wall in the dermatophyte Trichophyton mentagrophytes, was investigated by light and electron microscopy. Time-lapse photomicroscopy revealed that the new septa were inserted regularly along the length of the hypha. Each new septum divided a preexisting hyphal segment into approximately equal halves. The initial sign of arthroconidium formation detected by electron microscopy was the deposition of a conidium-specific wall layer on the inner surface of the preexisting hyphal wall. The invaginating septal material was continuous with the newly deposited inner wall layer of the sporulating hyphae. When septation was completed, the septum and septal furrow were continuous across the wall to the inner edge of the outer wall layer. After septation, the inner wall continued to thicken until it attained the thickness of a mature arthroconidial wall (0.3 – 0.5 μm). Simultaneously, immature arthroconidia continued to swell and eventually assumed a barrel shape. When disarticulated, arthroconidia were surrounded by the newly formed conidial wall at the poles, and the sides of the conidia were additionally bounded by the residual hyphal wall. As the arthroconidia matured, the remnants of the hyphal wall tended to be detached from the spore surface. From these observations we conclude that T. mentagrophytes formed arthroconidia by the enteroarthric mode rather than the holoarthric process as previously described.
Isolation and characterization of Methanobacterium uliginosum sp. nov. from a marshy soil
Authors: König Helmut
Published: May 2010

A rod-shaped Gram-positive methanogenic bacterium was isolated from marshy soil. It uses H2 – CO2 as sole energy and carbon source. Optimal growth occurs around 40 °C. The cell wall contains pseudomurein. The G + C content of the DNA is about 32 mol%. The DNA – DNA homology values of the isolate with Methanobacterium bryantii strains M.o.H. and M.o.H.-G. are 53 and 7%, respectively. The isolate is considered to be a new species within the genus Methanobacterium and it was named Methanobacterium uliginosum.
Hyphal interactions between a mycoparasite, Pythium nunn, and several soil fungi
Authors: Lifshitz R. , Dupler M. , Elad Y. , Baker R.
Published: May 2010

The modes of hyphal interaction between a mycoparasite, Pythium nunn, and several soil fungi were studied by both phase-contrast and scanning-electron microscopy. In the zone of interaction, Pyth. nunn massively coiled around and subsequently lysed hyphae of Pyth. ultimum and Pyth. vexans. In contrast, Pyth. nunn penetrated and eventually parasitized hyphae of Rhizoctonia solani, Pyth. aphanidermatum, Phytophthora parasitica, and Phyto. cinnamomi by forming appressoriumlike structures. However, Pyth. nunn was not mycoparasitic against Fusarium oxysporum f.sp. cucumerinum or Trichoderma koningnii and was destroyed by T. harzianum and T. viride. These observations demonstrated that Pyth. nunn was a necrotrophic mycoparasite, with a limited host range and differential modes of action among suscepts.
Lateral flagellum of Vibrio fluvialis: a species-specific antigen
Authors: Shinoda Sumio , Nakahara Noriko , Kane Haruaki
Published: May 2010

Antiserum against lateral flagella (L flagella) of Vibrio fluvialis AQ 0007 was prepared, and H agglutination tests of V. fluvialis strains were carried out with the antiserum. Thirty-seven strains isolated from human patients, marine products, or seawater were tested. All strains, except three which had lost the ability to form L flagella, agglutinated with that antiserum. The antiserum did not agglutinate other vibrio species having L flagella, whereas antisera against L flagella of other vibrios did not agglutinate V. fluvialis. These results suggest that the L flagellar antigen of V. fluvialis is common and specific to the species, and is a useful tool for serological identification of the organism.
Specificity of virus adsorption to clay minerals
Authors: Lipson Steven M. , Stotzky G.
Published: May 2010

Competitive adsorption studies indicated that reovirus type 3 and coliphage T1 did not share common adsorption sites on kaolinite and montmorillonite. Compounds in the minimal essential medium (e.g., fetal bovine serum, amino acids) in which the reovirus was maintained blocked adsorption of coliphage T1 to kaolinite and partially to montmorillonite in synthetic estuarine water, but they had no effect on coliphage adsorption to montmorillonite in distilled water or on the adsorption of the reovirus to either clay. The blockage of positively charged sites on kaolinite or montmorillonite by treatment of the clays with sodium metaphosphate or with the supernatants from montmorillonite or kaolinite, respectively, had no effect on adsorption of the reovirus. These data indicate that there was a specificity in adsorption sites for mixed populations of reovirus type 3 and coliphage T1 and emphasize the importance of using more than one type of virus, especially in combination, to predict virus behavior (e.g., adsorption, loss of infectivity) in soils and sediments containing clay minerals.
Metabolites of Cercospora arachidicola. The first report of long-chain fatty aldehydes from a fungus
Authors: Stoessl A.
Published: May 2010

Long-chain fatty aldehydes are reported for the first time as fungal products. They were isolated from potato dextrose agar cultures of Cercospora arachidicola as mixtures that were found by analytical procedures to consist predominantly of penta-and heptadecanal and heptadec-8-enal. Small to trace amounts of tetra-, hexa-, and nonadecanal, tetra- and pentadec-2-, and pentadec-6-enal, and heptadec-8,11 -dienal were also present, together with a mono- and a di-unsaturated C16 aldehyde. Brassicasterol was also isolated.
Nitrite and nitrous oxide production by Methylosinus trichosporium
Authors: Yoshinari Tadashi
Published: May 2010

Conditions for the production of nitrite and nitrous oxide by an obligate methanotroph, Methylosinus trichosporium (OB 3b), were studied. The rate of nitrite production [Formula: see text] was correlated with the concentration of ammonia up to 20 mM in the presence of sufficient amounts of oxygen and inversely correlated with the amounts of methane in the system. The rate of nitrous oxide (N2O) production [Formula: see text] was correlated positively with [Formula: see text] and the amount of nitrite produced and inversely with the oxygen concentration in the system. Nitrite started to disappear when either oxygen or methane or both were depleted, but only a part of the loss could be accounted for by an increase in N2O. Maximum rates of nitrite and N2O production by Ms. trichosporium were 6.9 ×5 1016 and 2.2 × 10−17 mol∙cell−1∙day−1, respectively. These values are about 0.2 and 1.6% of the values for Nitrosomonas europaea. Therefore, production of nitrite and N2O by methanotrophs in aquatic environments may not be as significant as that of Nitrosomonas.
Growth, cell cultivation, cell metabolism, and the cell cycle of Candida utilis as explored by continuous phased culture
Authors: Dawson P. S. S.
Published: May 2010

The problem of microbial growth, centred both on the population and the cell, and studied largely in batch culture, is also accessible by open methods of continuous culture which release such growth studies from restrictions imposed by the traditional methods. Thus, continuous phased (synchrony) culture enables studies of the cell cycle to be conducted systematically under different conditions of nutrient limitation and growth rate, and allows the phenotypic changes of chemostat steady states to be expressed as patterns of "cell cycle" behaviour over the doubling time. Studies conducted with Candida utilis in this way, in carbon-, nitrogen-, phosphorus-, and other nutrient-limited growths, have revealed a variable behaviour in the cell cycle, especially in the G1 period. Such variability in cell cycle behaviour is closely linked to the nutrient control of growth in the culture and generally accords with the Monod growth theory. Such variable behaviours for the cell are examined and assessed in relation to leading contemporary models for the cell cycle.
The effect of surfactants on the attachment of estuarine and marine bacteria to surfaces
Authors: Paul John H. , Jeffrey Wade H.
Published: May 2010

The effect of dilute surfactants on bacterial attachment to hydrophilic and hydrophobic substrata has been investigated. Triton X-100 at 0.002% completely inhibited attachment to polystyrene, a hydrophobic surface, for 10 of 11 isolates and all isolates at 0.01%. This concentration of surfactant also caused displacement of previously attached Vibrio proteolytica cells. Attachment to glass, a hydrophilic substratum, was far less sensitive to surfactants, and one isolate showed no inhibition at 0.1%, the highest concentration employed. Concentrations of surfactant sufficient to completely inhibit attachment had no effect on growth. In view of these results, it is thought that toxicity is not the mode of action of the surfactants, but rather disruption of hydrophobic interactions between the cell surface and polystyrene. The results imply the existence of a separate, surfactant-independent adhesion mechanism for hydrophilic surfaces in several isolates.
Effect of calcium on the in vivo assembly of the surface protein of Aquaspirillum serpens VHA
Authors: Koval S. F. , Murray R. G. E.
Published: May 2010

Aquaspirillum serpens VHA grown in minimal medium supplemented with 0.5 mM calcium possesses the regularly structured (RS) superficial protein layer. Cells grown in calcium-deficient medium lack the RS layer, but secrete small amounts of RS protein into the culture supernatant. Thus calcium is not required for synthesis of this protein. Addition of 0.5 mM calcium to midexponential phase cells in calcium-deficient conditions results in the rapid (within 10 min) assembly of a stable RS layer on the outer membrane. The RS layer is assembled from secreted and newly synthesized protein. No periplasmic pool of RS protein was found in calcium-deficient conditions. It is suggested that calcium is required to establish the correct conformation of the protein to allow assembly.
Determination of mercury and organomercurial resistance in obligate anaerobic bacteria
Authors: Rudrik James T. , Bawdon Roger E. , Guss Stephen P.
Published: May 2010

A methodology for determining the minimum inhibitory concentration of inorganic and organomercurial compounds for obligate anaerobic bacteria is described. A wide variation in the susceptibility of anaerobic clinical and sewage isolates was observed. Isolates of Bacteroides ruminicola and Clostridium perfringens resistant to mercury were examined for their plasmid content and ability to demonstrate inducible resistance. None of the resistant anaerobes contained any plasmids, while resistant facultative isolates from the same source contained several plasmids. In 24 h, resistant strains of Clostridia and Bacteroides volatilized 20 and 43% of the 203Hg2+ added to cultures, while Escherichia coli R100 and a sewage isolate of Enterobacter cloacae volatilized 63 and 27%, respectively, of the added 203Hg2+. Attempts to induce mercury resistance in the aerobic isolates were successful, but no induction was seen in the anaerobes. Thus, mercury resistance in these anaerobic isolates was neither inducible nor plasmid mediated.