Jaroslav Weiser

Bacteria associated with the nematode Neoaplectana carpocapsae and the pathogenicity of this complex for Galleria mellonella larvae

Abstract The microflora of the nematode Neoaplectana carpocapsae and its host Galleria mellonella was examined. In predominating quantity, Alcaligenes odorans, Pseudomonas fluorescens, P. maltophilia, P. alcaligenes , and Acinetobacter sp. were present in the nematodes. The quantitative ratio between the surface and the gut microflora was established. Virulence of the bacteria for Galleria larvae was determined, as was the degree of mortality of Galleria larvae caused by axenic nematodes infected with pure culture of these bacteria. In this system, nematodes do not merely work as a “living syringe” for bacteria when invading the host and thus introducing bacteria into the insect.

Microsporidia in Invertebrates: Host-Parasite Relations at the Organismal Level

In studies on the relationship of the microsporidia to their invertebrate hosts, the identification of the individual species is of primary importance. This exercise, however, is becoming increasingly difficult in view of the growing number of microsporidia isolated from new hosts and the limited number of diagnostic factors for species identification. According to a recent world census, the number of invertebrate species is estimated to be nearly one million. My experience in distribution of microsporidia of invertebrate hosts indicates that there may be a microsporidian in every living invertebrate. If only one per cent were new species, there would be as many as 10,000 species to distinguish. Obviously, it would be a monumental task to distinguish this large number. Therefore, the extreme care is necessary to record all characteristics.

On the taxonomic position of the fungus discovered by Strong, Wells, and Apple: Strongwellsea castrans gen. et sp. nov. (Phycomycetes; Entomophthoraceae)

Abstract A fungus discovered by Strong, Wells, and Apple in 1960 is described as Strongwellsea castrans gen. et sp. nov. (Phycomycetes, Entomophthoraceae). The fungus causes a disease of the seed-corn maggot, Hylemya cilicrura (Rondani); it destroys most organs of the insects abdomen where spherical mycelial masses with a central cavity are formed. A layer of conidiophores is differentiated later in their interior and one or two holes connect their interior with the exterior by round openings. Strongwellsea castrans is the most specialized parasite of the Entomophthoraceae, close to Massospora spp. The host is not killed but is sterilized by the fungus. Mature conidia are liberated through the opening of the holes.

The Pleistophora debaisieuxi Xenoma

SummaryMicrosporidia form in the xenomas with their hosts a special type of relation. The host cell and the parasite represent together a physiological and morphological unit. In this relation the sporonts of Pleistophora debaisieuxi cause divisions of fat body cells of blackflies to an extent that each parasite sporont is finally closed in a specific host cell, the xenocyte, with a permanent functioning nucleus and a cytoplasmic coat which remains persistent during the whole sporogony of the microsporidian.Two main types of xenomas are differentiated: the syncytial, in which the infected cells dissolve their limiting membranes and form a multinuclear plasmodium, in some cases with nuclear hypertrophy, and the neoplastic in which the number of induced xenocytes (infected host cells) is much higher than the original number of fat body cells, an analogy of tumor formation. In this group we include the Glugea-cyst as a specific case with neoplastic nuclear divisions of the primary cyst cell.

Seven new microsporidian parasites of springtails (Collembola) in the Federal Republic of Germany

Three new species ofNosema (N. lepidocyrti, N. onychiurus andN. petrosa), oneEncephalitozoon (E. flavescens) two species ofThelohania (T. bomboschi andT. collembolae) and a new genusAuraspora n.g. withA. canningae were described from Collembola in soil samples of Lower Saxony, Federal Republic of Germany.ZusammenfassungObwohl die Springschwänze (Collembola) als wichtige Streuzersetzer seit langem Gegenstand bodenbiologischer Forschung sind, gab es bisher keine Hinweise auf das Vorkommen pathogener Protozoen als Parasiten dieser Insekten. Im Rahmen einer vergleichenden Bodentieruntersuchung in verschiedenen Waldstandorten Niedersachsens wurden 1320 Collembolen auf Parasitierung durch pathogene Protozoen geprüft. Dabei konnten erstmals Mikrosporidien (Microsporida, Protozoa) als Krankheitserreger von Collembolen festgestellt werden. Sie werden neu beschrieben:Nosema lepidocyrti sp.n. inLepidocyrtus lignorum Tullberg (Tomoceridae),Nosema onychiurus sp.n. inOnychiurus quadriocellatus Gisin (Onychiuridae),Nosema petrosa sp.n. inLepidocyrtus cyaneus Tullberg (Tomoceridae),Thelohania bomboschi sp.n. inTomocerus flavescens Tullberg (Tomoceridae),Thelohania collembolae sp.n. inL. lignorum undT. flavescens, Encephalitozoon flavescens sp.n. inT. flavescens.Eine Art ist keinem bekannten Genus zuzuordnen:Auraspora gen.n.canningae sp.n. inL. lignorum.Der nachgewiesene Mikrosporidienbefall betrug beiO. quadriocellatus 3% (n=220),L. lignorum 7% (n=130),T. flavescens 8%(n=193) andL. cyaneus 6% (n=63).

Susceptibility of ribosomes of the tetracycline-producing strain of Streptomyces aureofaciens to tetracyclines.

Ribosomes from cells of Streptomyces aureofaciens producing tetracycline antibiotics (Tc‐ribosomes) differ in electrophoretic mobility of ribosomal proteins S2, S10 and L19 from those of the same strain, where the production of tetracyclines was suppressed by changed cultivation conditions (C‐ribosomes). Purified tight vacant couples C‐ and Tc‐ribosomes are equally active in the translation of poly(U). Both types of S. aureofaciens ribosomes are more sensitive to tetracycline and chlortetracycline than ribosomes of Escherichia coli in the Phe‐tRNA binding and the translation of poly(U).

Electron-microscope studies of Rickettsiella chironomi in the midge Camptochironomus tentans

Abstract The rickettsial etiology of a disease in the midge Camptochironomus tentans , was proved by electron microscopy of 25-year-old “type” material. Rickettsiella chironomi is an oval, flattened organism with a special system of cylindrical ridges covering its body in a layer beneath the covering or outer membrane. Other ultrastructures of the organism and of N-R-like bodies in infected tissues are described.

Ribosomal proteins of Streptomyces aureofaciens producing tetracycline

Three different two-dimensional polyacrylamide gel electrophoretic systems were employed for identification of individual ribosomal proteins of Streptomyces aureofaciens. Proteins of small subunits were resolved into 21 spots. Larger ribosomal subunits contained 35 proteins. The separated ribosomal proteins from 50 S subunits were transferred on nitrocellulose membranes for immunochemical estimations. Antibodies developed against 50 S proteins of S. aureofaciens and Escherichia coli were used for identification of structural homologies between 50 S proteins of the two species. Results of the experiments indicate that about one half of the 50 S proteins of S. aureofaciens share common immunochemical determinants with corresponding proteins of 50 S subunits of E. coli. Evidence is presented that acidic ribosomal protein SL5 of large ribosomal subunits of S. aureofaciens can be assembled to E. coli P0 cores lacking proteins L7/L12. Reconstitution of the P0 cores with proteins SL5 or L7/L12 led to restoration of 78% activity in polyphenylalanine synthesis.

Ribosomal proteins of Streptomyces granaticolor

Abstract A method for large-scale isolation of streptomycete ribosomal subunits involving centrifugation in hyperbolic sucrose density gradients in a zonal rotor was developed. Ribosomal proteins were extracted from 30 S and 50 S subunits of Escherichia coli A19 and primary mycelium of Streptomyces granaticolor . Their two-dimensional electropherograms differed considerably. Purified 30 S and 50 S subunits from S. granaticolor mycelium contained 21 and 36 ribosomal proteins, respectively. Only 8 proteins in the mycelial ribosomes possessed identical electrophoretic mobilities as corresponding E. coli ribosomal proteins, viz., S4, S12, S16, L1, L2, L14, L16 and L19. Despite the differences in physico-chemical properties, functional correspondence is likely to exist between certain ribosomal proteins from the two bacteria. The range of molecular weights of vegetative S. granaticolor ribosomal proteins was similar to that in other prokaryotes. Ribosomal proteins were further isolated from 70 S ribosomes of S. granaticolor dormant spores. The spore ribosomal proteins differed markedly from those of the primary mycelium and their total number was lower. The ribosomal protein alterations are presumed to take part in the regulation of the streptomycete cell differentiation.

Different course of proteolytic inhibitory activity and proteolytic activity in Galleria mellonella larvae infected by Nosema algerae and Vairimorpha heterosporum

Abstract The activity of protease inhibitors and proteases was studied in the hemolymph, gut, and fat body of 7th-instar larvae of Galleria mellonella infected by two microsporidia, Nosema algerae and Vairimorpha heterosporum . The increase in inhibitory activity in the hemolymph was substantial, and coincided with the development of the disease. The increase in inhibitory activity in the gut was almost doubled by N. algerae as compared with V. heterosporum , whereas the increase in inhibitory activity in fat body was found only in V. heterosporum -infected larvae. The course of proteolytic activity followed an inverse pattern to the elevated activity of inhibitors in the gut and the fat body, and rose only in moribund larvae at the end of the course of V. heterosporum infection. The differences in the pattern of proteases and inhibitors reflect the organ specificity of each of the microsporidia.