What can phylogeographic breaks in the livebearer Poeciliopsis turrubarensis tell about fish community boundaries in western Costa Rica?

This study asks if the geographic boundary delineating two fish communities in western Costa Rica is congruent with a phylogeographic break in a single widespread fish species Poeciliopsis turrubarensis (Poeciliidae) that spans this area. Such congruence would suggest that a common historical event (e.g. geological or climatic) could be responsible for both patterns. It was found that there was a shared break across a region in central Costa Rica suggesting a common cause may be responsible for both the abrupt shift in fish community composition and the genetic break in P. turrubarensis.

Effect of tetracycline on the attachment of K88+ enterotoxigenic Escherichia coli to porcine small-intestinal cells.

The attachment of six strains of K88+, porcine pathogenic, enterotoxigenic Escherichia coli to isolated porcine intestinal mucosal cells was decreased following growth in the presence of concentrations of oxytetracycline below the minimal inhibitory concentration (MIC). The decrease in binding by the wild-type strains was detected at concentrations of drug as low as 0.001 microgram/ml, which was greater than four orders of magnitude below the MIC. When drug resistance was induced in these six strains, there was still a decrease in binding when the bacteria were grown in the presence of tetracycline. This decrease was comparable to the decrease in binding capacity of the wild-type strains caused by growth in the presence of tetracycline. In contrast, when one strain (G1108E) was made tetracycline resistant by the introduction of the R16 plasmid, the antibiotic had less effect on the binding of this strain than on the wild-type strain; however, growth in the presence of antibiotic still decreased adhesion. Overall, oxytetracycline decreased the adhesion of wild-type, induced-resistant, and genetically resistant K88+ enterotoxigenic E. coli to porcine small-intestinal cells, and this effect occurred at antibiotic concentrations several orders of magnitude below the MIC.

High-yield preparation of purified Anaplasma marginale from infected bovine red blood cells.

Purification of Anaplasma marginale from infected bovine RBC was achieved through enzyme treatment and density-gradient centrifugation. A relative yield of 41.6% was obtained by dividing the number of organisms in the final purified preparation by the number of A marginale-infected RBC. Purified parasites were verified as A marginale by light microscopy, electron microscopy, and immunologic tests. The purified parasites reacted positively with calf and rabbit anti-A marginale sera in interfacial and slide agglutination tests. Anti-bovine RBC serum did not agglutinate purified A marginale, indicating absence of any contaminating RBC stroma. Anaplasma marginale was antigenic, but did not cause infection when the preparation was inoculated into a susceptible calf. The density of A marginale was determined to be 1.19 g/ml and cell diameters ranged from 0.25 to 0.63 micron. This method provided procedures for obtaining A marginale free of bovine RBC antigens for accurate biochemical assays and vaccine production.

Phosphonate Utilization by the Glyphosate-Degrading Pseudomonas sp. Strain PG2982.

The glyphosate-degrading Pseudomonas sp. strain PG2982 was found to utilize each of 10 organophosphonate compounds as a sole phosphorus source. Representative compounds tested included alkylphosphonates, 1-amino-substituted alkylphosphonates, amino-terminal phosphonates, and an arylphosphonate. This report demonstrates that PG2982 is capable of utilizing a wider range of structurally different organophosphonate compounds than any organism described to date.

Attachment of human and pig (K88) enterotoxigenic Escherichia coli strains to either human or porcine small intestinal cells.

Enterotoxigenic Escherichia coli strains pathogenic for humans and enterotoxigenic E. coli strains pathogenic for pigs producing the K88 pili antigen both bound to isolated small intestinal cells from either humans or pigs. Neither the K99 enterotoxigenic E. coli (from lambs and calves) nor the rabbit pathogenic strain RDEC-1 bound to human or pig small intestinal cells under the same conditions.

Structure and cell envelope associations of flagellar basal complexes of Vibrio cholerae and Campylobacter fetus.

To isolate intact flagella with basal complexes from Vibrio cholerae, a rhamnolipid hemolysin from Pseudomonas aeruginosa was used to disrupt the cell envelope and flagellar sheath. The nonionic detergent, Triton X-100, provided similar results for Campylobacter fetus. Each of these basal complexes possessed, in addition to the four classical rings, concentric membrane rings (CMR's) similar to those found in Aquaspirillum serpens. Through the use of stereo imaging (which allows structures to be visualized in three dimensions) of thin sections of cells which had been sequentially treated with a number of envelope perturbants (i.e., ethylenediaminetetraacetate, lysozyme, Triton X-100, rhamnolipid hemolysin, and sodium dodecyl sulfate), we have progressively exposed the component parts of the basal organelles in V. cholerae and C. fetus. Since the action of these envelope perturbants has been well documented, we have been able to determine the associations of the exposed portions of the flagellar basal complex and the layer of the cell envelope in which they would normally reside. From our observations we have concluded that in both V. cholerae and C. fetus the L ring is embedded in the outer membrane and the P ring is associated with the peptidoglycan. The CMR's are bracketed by the L and P rings and are sandwiched between the outer membrane and the peptidoglycan. Elements of both the S and M rings appear to be associated with the plasma membrane.

Presumptive identification of Vibrio species with H antiserum.

Species in the genus Vibrio exhibit flagellar (H) antigens unique to the species. Thus, species-specific H antiserum could be a valuable reagent with which to screen serologically large numbers of Vibrio isolates. Antisera against V. cholerae, V. fluvialis, V. anguillarum, V. metschnikovii, V. parahaemolyticus, V. alginolyticus, and V. vulnificus H antigens was produced in rabbits by repeated injections of Formalin-preserved whole cells. Anti-O activity and anti-H activity against common H antigens was absorbed from each antiserum, V. fluvialis was shown to possess an H antigen unique to the species and also to share minor H antigens with V. cholerae, V. metschnikovii, and V. anguillarum. V. vulnificus also exhibits a species-unique H antigen. A comprehensive serological screening system based on species-specific H antiserum was developed to identify pathogenic Vibrio species one step beyond primary isolation. Vibrio species were correctly identified with accuracies ranging from 93 to 100%. Some isolates were either nonmotile or poorly so and thus did not flocculate in H antiserum.

Isolation of a Pseudomonas sp. Which Utilizes the Phosphonate Herbicide Glyphosate.

A strain of bacteria has been isolated which rapidly and efficiently utilizes the herbicide glyphosate (N-phosphonomethylglycine) as its sole phosphorus source in a synthetic medium. The strain (PG2982) was isolated by subculturing Pseudomonas aeruginosa ATCC 9027 in a synthetic broth medium containing glyphosate as the sole phosphorus source. Strain PG2982 differs from the culture of P. aeruginosa in that it is nonflagellated, does not produce pyocyanin, and has an absolute requirement for thiamine. Strain PG2982 has been tentatively identified as a Pseudomonas sp. strain by its biochemical activities and moles percent guanine plus cytosine. Measurements of glyphosate with an amino acid analyzer show that glyphosate rapidly disappears from the medium during exponential growth of strain PG2982. In batch culture at 30 degrees C, this isolate completely utilized 1.0 mM glyphosate in 96 h and yielded a cell density equal to that obtained with 1.0 mM phosphate as the phosphorus source. However, a longer lag phase and greater generation time were noted in the glyphosate-containing medium. Strain PG2982 can efficiently utilize glyphosate as an alternate phosphorus source.

Costa as a glycogen store and probable site of energy generation in Tritrichomonas foetus.

Costae were isolated from the parasitic protozoan Tritrichomonas foetus and were found to contain 87% of the total cellular glycogen. Radiotracer studies, using [U-14C]glucose, were performed on starved and unstarved whole cells and on costae isolated from starved and unstarved cells. During cell starvation, catabolism of labeled costal glycogen was demonstrated. Preferential utilization by the cell of costal glycogen over other cellular glycogen stores was indicated.

Bacillus thuringiensis distribution in soils of the United States.

During a 2-year study, samples of various types of soils were collected from 115 fields that had not previously been tested with Bacillus thuringiensis and which were remote from any large-scale aggregations of lepidopterous insects in rearing or grain-storage areas. An average of about 400 isolates were examined from each soil, and, of 46 373 isolates examined, only 250 (0.5%) were identified as B. thuringiensis. While it was almost impossible to insure that a field had never been treated with B. thuringiensis or that drift from some nearby application had not reached the field, it is noteworthy that of the 250 isolates, 156 (62.4%) were not var. kurstaki, the only variety that has been used commercially in the United States in about 10 years. This is a strong indication that the B. thuringiensis isolates observed were present naturally. To verify the procedures used, samples were taken from two adjacent experimental plots which had been treated about 12 months previously with formulations of var. kurstaki and var. galleriae, respectively. With practically no exception, the variety recovered from each plot was the variety applied, indicating that the varietal status of B. thuringiensis is stable in the soil.

Isolation of O1 serovars of Vibrio cholerae from water by serologically specific method.

Vibrio cholerae bacteria of the serological variety O1 were consistently isolated from water samples by passing the water with added Tween 20 through columns packed with polystyrene beads coated with antibodies against the O1 antigenic determinants. The beads from the columns were washed, transferred to alkaline peptone broth, and incubated. The O1 serovars were isolated and identified by established procedures.

Characterization of a flagellar sheath protein of Vibrio cholerae.

A flagellar sheath protein of Vibrio cholerae CA401 (Inaba) was characterized. Purity of the preparation was indicated by a single band on polyacrylamide gel electrophoresis gels and on Ouchterlony plates prepared with antibody against crude sheath material. The sheath protein was composed of three polypeptides with minimal molecular weights of 61,500, 60,000, and 56,500. The presence of sheath protein on the flagellum as well as on the outer membrane of the cell was demonstrated by ferritin labeling experiments with antiserum. Sheath protein antibody reacted similarly in labeling experiments and agglutination tests with a classical Ogawa strain and two nonagglutinating V. cholerae isolates, indicating that the sheath protein may represent the common Vibrio H antigen. Antibody specific for lipopolysaccharide labeled the cell but not the sheathed flagellum, which demonstrated that the sheath is not a simple extension of the outer membrane of the cell.

An immunodiffusion test for detection of bovine viral diarrhea virus antibodies in bovine serum.

An immunodiffusion test (IDT) was developed for detecting bovine viral diarrhea virus antibodies in bovine serum. The antigen utilized in the IDT was prepared from bovine viral diarrhea virus-infected monolayer cultures. Results of the IDT were obtained within 48 hours and correlated with the virus-neutralization test.

Purification and characterization of the extracellular proteinase of Serratia marcescens.

The extracellular proteinase produced by a depressed strain of Serratia marcescens ATCC 25419 was purified and characterized. This produces more than 10-times the amount of extracellular proteinase produced by other strains of Serratia tested. The purified enzyme was prepared from the culture supernatant by (NH4)2SO4 fractionation and DEAE-cellulose chromatography. The purified enzyme has an so20,w of 3.95 and is a monomer of molecular weight 51,900. The proteinase has a broad pH optimum in the alkaline range with a maximum at pH 9.5. The enzyme will utilize a number of proteins as substrate. The products of digestion are primarily in the size range of tripeptides to hexapeptides. Peptides containing a sensitive bond and a minimum size of size amino acids are hydrolyzed. The proteinase is inhibited by chelating agents but unaffected by sulfhydryl or serine reagents and is devoid of esterase activity.

Isolation of Plasmodium berghei by hemolysin lysis of infected erythrocytes and evidence for a parasite hexokinase.

A rapid and simple procedure has been developed for the isolation of Plasmodium berghei parasites from infected-mouse erythrocytes employing the heat stable hemolysin produced by Pseudomonas aeruginosa. Using parasites isolated by this method, the presence of a parasite specific hexokinase has been demonstrated, providing an explanation for the increased glucose consumption observed with infected cells. Enzyme assays and serology were employed in determining the purity and yield of purified parasites. The enzyme assays showed that about 25% of the parasites in infected RBCs were recovered in the purified state. The purified parasites were not agglutinated by rabbit-anti-mouse RBC serum which indicated the purified parasites were not contaminated by RBC components.

Purification of the protein employed in an immunodiffusion test to diagnose infectious bovine rhinotracheitis.

The antigen used in an immunodiffusion test to diagnose infectious bovine rhinotracheitis has been purified by affinity chromatography. The homogeneity of the antigen was indicated by sedimentation rate and sedimentation equilibrium experiments. A So20,w of 0.749 was determined and a molecular weight of 8900 was calculated from sedimentation equilibrium analysis. The purified antigen formed precipitin lines of identity with crude diagnostic antigen. Purified antigen remained serologically active in the immunodiffusion test after lyophilization and subsequent reconstitution.

Costae of Tritrichomonas foetus: purification and chemical composition.

The costa is an intracellular organelle common to all trichomonads. Costae from Tritrichomonas foetus have been purified by a method which involves lysis of T. foetus with the heat-stable hemolysin produced by Pseudomonas aeruginosa, followed by differential centrifugation. Analysis of the purified costae demonstrated that the organelle is composed of 95 percent carbohydrate and 5 percent protein. The carbohydrate moiety, probably a polysaccharide, consisted of glucose (95 percent), mannose (0.4 percent), glucosamine (1.4 percent), ribose (0.6 percent), and an unidentified sugar (2.6 percent). The kinetosomal complex was attached to the costa after initial lysis of cells but was separated from the costa during purification.

Microimmunodiffusion test for detection of antibodies to infectious bovine rhinotracheitis virus in bovine serum.

A microimmunodiffusion test (MIDT) specific for detection of antibodies to infectious bovine rhinotracheitis (IBR) in bovine serum has been developed. The antigen used in the MIDT was prepared from IBR virus-infected Madin-Darby bovine kidney cells grown in tissue culture. The antigen was stable, and relatively high yields were obtained readily. Results of the MIDT were obtained within 48 hours and agreed with those of the serum-neutralization test.