Fish Spines Research Articles

An antagonist of streptomycin and dihydrostreptomycin produced by Pseudomonas aeruginosa.

SUMMARY: A substance produced by Pseudomonas aeruginosa (P. pyocyanea) which antagonizes the activity of streptomycin and dihydrostreptomycin, and which will itself inhibit bacterial growth in low concentrations, has been isolated in a crystalline form. The antagonist at 0.01 μg./ml. was capable of antagonizing the action of 1000 times its weight of dihydrostreptomycin against Bacillus subtilis or B. pumilus. It was much less active against Escherichia coli. Growth of B. subtilis and B. pumilus was inhibited by less than 1 μg. antagonist/ml. under conditions which required a concentration of 6 μg. dihydrostreptomycin sulphate/ml. to inhibit growth. A method of assay of antagonist activity, capable of assaying solutions containing 0.01 μg. antagonist/ml., was developed. It was a cup-plate method which depended on the production of zones of exhibition. Plates poured with seeded nutrient agar containing an inhibitory concentration of dihydrostreptomycin were used, and the samples of antagonist were placed on the surface of the agar in fish spine beads. The zones of exhibition developed during incubation of the plates and the potency of the samples could be determined from a comparison with zones produced by a standard preparation on the same plate. The antagonist was produced by most strains of Pseudomonas aeruginosa under favourable conditions. Its production in fluid culture depended on vigorous aeration, but too high an aeration rate or foaming of the culture produced low yields. Strains of other organisms which were examined, for example, Staphylococcus aureus, Escherichia coli, Serratia marcescens, Bacterium bodenheimer, streptococci of Lance-field's Group D, Bacillus subtilis and B. pumilus, did not produce antagonist. The antagonist was extracted from fluid culture by n-butanol; the butanol was removed by distillation in an atmosphere of nitrogen, and the residue fractionated by precipitation from benzene solution by addition of light petroleum. The success of the fractionation was dependent on obtaining an initial butanol extract containing at least 100 μg. antagonist/mg. total solids. This in turn was dependent on the use of a simple chemically defined culture medium for production, and the choice of a strain of Pseudomonas aeruginosa which produced a high yield of antagonist. The crystalline antagonist has the formula C17–18H23–24NO2 and a molecular weight of the order 300–400. It is stable in the dry crystalline state, but readily oxidized in solution. It is soluble in ethanol and butanol, less soluble in benzene, and relatively insoluble in light petroleum. Its maximum solubility in water at room temperature at pH 7.0 is c. 10 μg./ml.; at pH 9.0 it is 20–30 μg./ml.

A New Plant ( Thallomia ) showing Structure, from the Downtonian Rocks of Llandovery, Carmarthenshire

The curious fossil which is here described and figured was discovered in a quarry about 50 yards north-west of Capel Horeb on the main road between Llandovery and Brecon (fig. 1). Most of the rocks of the quarry consist of thickly bedded, bluish-grey, highly micaceous sandstones (Tilestones) of Lower Downtonian age, which locally approach quartzites in composition. Many calcareous bands of fossils are intercalated with these Tilestones. The fossil fauna of this quarry and of others in the immediate neighbourhood has been noted and recorded by several workers, including Dr. L. D. Stamp and, more recently, Mr. S. H. Straw, who records the following fauna from this horizon:— Cornulites serpularius Sclotheim. Small Rhynchonellid. Cucullella antiqua (J. de C. Sowerby). Grammysia extrasulcata Salter. Modiohpsis complanata (J. de C. Sowerby). Bellerophon trilobatus (J. de C. Sowerby). Holopella obsolete (J. de C. Sowerby). Platyschisma helicites (J. de C. Sowerby). Orthoceras sp. Kloedenia (Beyrichia) wilckensiana (Jones). Fragment of a fish spine. The plant recorded in this communication has been obtained, not from the sandstones which occupy the major part of the quarry, but from a lenticular patch of gritty micaceous shales which is interbedded with them (PL XLIII, fig. 1). The lenticle is bounded by a lighter-coloured zone, 4 inches wide, of fine-grained

Fossil Fish-remains from Carboniferous Shales at Cultra, Co. Down, Ireland

Some time ago I received a small collection of fossil fish-remains collected from the dark carboniferous shales at Cultra, Co. Down, in Ireland, by Mr. Chas. Bulla, of Belfast. The majority of the specimens are somewhat fragmentary and difficult to determine, but there are others which appear to add to the already rich fauna of the Carboniferous series of that country. The latter consists of two spines and a number of bony plates of a species of Cœlacanthus. In 1881, in a paper read at the Geological Society (Quarterly Journal, vol. xxxvii., p. 427), I described a number of spines obtained from the Cannel Coal at Tingley and the Lower Limestone series near Edinburgh. Similar in form to some members of the genus Pleuracanthus, they were readily distinguished by the entire absence of lateral or posterior rows of denticles. For these spines the generic name Anodontacanthus was suggested. They were straight and gradually contract in diameter towards the apex, which is more or less pointed. An internal cavity, wide at the base, extends nearly the whole length of the spine; from its resemblance to the form of the spine of Pleuracanthus, it is probable that the spine of Anodontacanthus was implanted in the same manner, possibly in a similar position behind the occipital region of the head, as in that genus. The fish spines from Cultra possess the generic characters of Anodontacanthus, they are straight and tapering, the internal cavity opens terminally, and they are without denticles. They are much ...

Index to the Localities

Avon, Banks of the, near Hamilton. Shales in the first precipitous cliff, left bank of the Avon above the bridge. Neuropteris gigantea, N. Loshii, Sphenopteris Hibbertii, Lepidodendron obovatum, and Calamites. Baillieston. Springhill coal pits. Plants are very abundant in the roof shale, and in ironstone nodules above the Pyotshaw coal. Alethopteris heterophyllia, Cyclopteris dilatata, Neuropteris gigantea, Pecopteris dentata, Sphenopteris dilatata, S. Honinghausi, Asterophyllites longifolia, A. tuberculata, Calamites nodosus, Sphenophyllum Schlotheimii, Lepidostrobus pinaster, Trigonocarpum ovatum; fish spines in the shales of the Splint coal. Bellshill. Coal pits between Bellshill and Motherwell. Plant-remains in the roof of the Main, and fish remains in the roof of the Splint coals. Bello Water, 1 mile E. of Lugar Station. Anthracosia robusta form a bed 18 inches in thickness. Carmyle. Coal pit near Carmyle Mill. Ferns in an arenaceous shale, and Gyracanthus formosus, Pleuracanthus gibbosus, Pleurodus, and Ctenoptychius pectinatus, in a bituminous shale, overlying the Splint coal. Carnbroe. Ironstone pit, No. 10. The roof shale of the Palace Craig ironstone contains Pholaderpeton, Pteroplax cornuta, Anthracosaurus Russelli, Loxomma Allmannii, Megalichthys Hibberti, M. coccolepis, M. rugosus, Acanthodes Wardii, Rhomboptychius, Strepsodus sauroides, Rhizodopsis minor, R. major, Gyracanthus formosus, G. tuberculatus, Pleuracanthus gibbosus, Ctenacanthus major, Cladodus, Ctenodus cristatus, C. tuberculatus; also several species of Lepidostrobus, Anthrapalaemon Grossarti, and Anthracosia. Mr. James Thomson has found in this bed three palatal teeth, Pleurodus Rankinii, P. affinis, and a Helodus embedded together in a mass of shagreen. Castlehill, 1 mile N. of Carluke. Coal pits. The remains of between thirty and forty This 250-word extract was created in the absence of an abstract

Mechanical jurisprudence.—No. III

In this first part of a two-part update on the streptococci, new and emerging pathogens in the “pyogenic cocci group” and the “Streptococcus bovis group” are addressed. Among the pyogenic cocci, several new species have been described, and some of these are becoming relevant agents of human disease. Streptococcus porcinus and Streptococcus pseudoporcinus are β-hemolytic streptococci that are found in swine and humans, respectively. S. pseudoporcinus has been isolated primarily from the female genital tract and may play a role in genitourinary tract infections, wound infections, and adverse pregnancy outcomes. Streptococcus iniae, Streptococcus hongkongensis, and Streptococcus ictaluri are fish pathogens, and S. iniae, in particular, has been isolated from several human infections in persons who handle raw seafood or experience penetrating injuries from fish spines or crab pincers. Streptococcus gallolyticus subspecies (i.e., the former “S. bovis group”) are well-recognized causes of bacteremia, meningitis, and endocarditis. S. gallolyticus subsp. gallolyticus is known to be associated with colon cancer, and current studies suggest that other S. gallolyticus subspecies (particularly S. gallolyticus subsp. pasteurianus) may also be associated with meningitis and other digestive tract malignancies. In this review, current research on S. gallolyticus subspecies and proposed mechanisms for their involvement in the pathogenesis of colonic carcinoma are also briefly addressed.