Observations onHexamermis albicans [Nematoda: Mermithidae] recovered fromLymantria dispar andStilpnotia salicis [Lep.: Lymantriidae] in west Germany and Austria

The mermithid,Hexamermis albicans (Siebold) was recovered from larvae ofLymantria (Porthetria) dispar (L.) collected from various localities in Burgenland, Austria in 1974 and 1975 and from Würzburg, Germany, in 1974. It was recovered also fromStilpnotia salicis (L.) in Austria in 1974. The mermithid was recovered from all field collected larval instars. The majority of the nematodes emerged fromL. dispar larvae collected as second and third larval instars although some nematodes were recorded from larvae collected as first instar larvae still on the egg mass. Peak emergence occurred in the laboratory during the period June 11–17 of both years, but emergence continued at a much lesser degree through the end of larval development. The nematode was found in both high and low host density populations. In 3 localities studied both years, there was a general increase in the percentage parasitism the second year. However, except for one locality in Austria in 1975 where individual samples produced up to 11% parasitism, the overall parasitism increased from 0.4% in 1974 to only 2.5% in 1975.     

Occurrence ofCandida albicans in fresh gull feces in temperate and subtropical areas

The occurrence ofCandida albicans in fresh gull (Larus spp.) feces was compared in temperate and subtropical locations. Of 239 fresh samples, 133 were obtained in southeastern Connecticut and 106 from different sites on the southeastern and central western coasts of Florida. Overall, 60% of all feces containedC. albicans. Of the Connecticut samples, 78% were positive, whereas 38% of the Florida samples revealed the presence of the yeast. Only 1 of 24 samples of fresh brown pelican feces containedC. albicans. Differences inC. albicans occurrence in birds in various locations was ascribed to variations in habitat and feeding behavior. Samples of water from a municipal reservoir in Connecticut were routinely positive, with an average cell density of 20/liter. Two fresh gull samples obtained on the reservoir bank containedC. albicans at an average cell concentration of 5, 200/g. The frequency ofC. albicans in gull droppings was higher than reported by others, and the yeast is common in temperate waters. These findings have important public health implications.     

Epidemiology and Antifungal Susceptibilities of Yeasts Causing Vulvovaginitis in a Teaching Hospital

Vulvovaginal candidiasis is one of the most common mycosis. However, the information about antifungal susceptibilities of the yeasts causing this infection is scant. We studied 121 yeasts isolated from 118 patients with vulvovaginal candidiasis. The isolates were identified by phenotypic and molecular methods, including four phenotypic methods described to differentiate Candida albicans from C. dubliniensis. Antifungal susceptibility testing was performed according to CLSI documents M27A3 and M27S4 using the drugs available as treatment option in the hospital. Diabetes, any antibacterial and amoxicillin treatment were statistically linked with vulvovaginal candidiasis, while oral contraceptives were not considered a risk factor. Previous azole-based over-the-counter antifungal treatment was statistically associated with non-C.albicans yeasts infections. The most common isolated yeast species was C. albicans (85.2 %) followed by C. glabrata (5 %), Saccharomyces cerevisiae (3.3 %), and C. dubliniensis (2.5 %). Fluconazole- and itraconazole-reduced susceptibility was observed in ten and in only one C. albicans strains, respectively. All the C. glabrata isolates showed low fluconazole MICs. Clotrimazole showed excellent potency against all but seven isolates (three C. glabrata, two S. cerevisiae, one C. albicans and one Picchia anomala). Any of the strains showed nystatin reduced susceptibility. On the other hand, terbinafine was the less potent drug. Antifungal resistance is still a rare phenomenon supporting the use of azole antifungals as empirical treatment of vulvovaginal candidiasis.     

A possible function of the chilamydospores of Candida albicans

Strains ofCandida albicans produce large numbers of chlamydospores in a liquid medium composed of 1% sodium taurocholate in distilled water. Studies made of these chlamydospores revealed that they do not contain endospores or ascospores but they do contain globules which are lipoid in character. These globules are extruded when chlamydospores split in the liquid medium or under slight pressure. Evidence was not obtained which could support van der Walt's (1967, 1969) statements to the effect that chlamydospores bud, germinate or change into other types of cells. Furthermore, no morphological or cytological evidence was found to substantiate the proposed life cycle ofC. albicans as outlined by van der Walt (1969). It is suggested that a possible function of the chlamydospores ofC. albicans is that of a storage cell.     

The diploidRorippa islandica discovered in Southern Europe

A revison of herbarium material ofRorippa, revealed the presence of the diploidRorippa islandica (Oeder exMurr.) Borb. (2n=16) in several localities in Jugoslavia (Bosnia-Hercegovina and Montenegro), and probably also in Italy (Etruria). All localities occur in altitudes above 1400 m a.s.l. and constitute an extension of the distribution area of this species to Appenine and Balkan Peninsula.     

Flocculation phenomenon of Candida albicans by lysozyme

Young colonies of Sabouraud's glucose agar room temperature culture ofCandida species from human isolation were suspended in distilled water. The suspension was mixed with a solution of lysozyme and incubated in a 37° C water bath. Within 3–5 hours, various species ofCandida cells showed flocculation to varying degrees which occurred at varying periods of onset. Among sevenCandida species,Candida albicans andCandida stellatoidea showed the strongest flocculation, earliest onset and most solution clarity than did any other species.Candida stellatoidea was indistinguishable fromCandida albicans in its degree of flocculation, and in the clarity of solution.Candida species may be arranged in the following order according to their decreasing positivity in flocculation:

1. Candida albicans
2. Candida stellatoidea
3. Candida tropicalis
4. Candida krusei
5. Candida pseudotropicalis
6. Candida parapsilosis
7. Candida guilliermondii
8. Saccharomyces species may be placed afterCandida guilliermondii.

It seems possible to separate theCandida species into 3 groups by the rate of flocculation, and clarity of solution. Group I.Candida albicans andCandida stellatoidea. Group II.Candida tropicalis, C. krusei andCandida pseudotropicalis. Group III.Candida parapsilosis andCandida guilliermondii. Saccharomyces specimens (S. cerevisiae and others) were placed after group III.     

Killing Rates for Caspofungin Against Candida albicans After Brief and Continuous Caspofungin Exposure in the Presence and Absence of Serum

It was previously demonstrated that brief (≤1 h) exposures to echinocandins are as effective to kill Candida albicans cells as continuous 24-h exposure. However, killing rates after continuous and short (1 h) echinocandin exposures to C. albicans have not yet been evaluated in RPMI-1640 with and without 50 % serum. We evaluated four echinocandin susceptible C. albicans bloodstream isolates, ATCC 10231 type strain and an echinocandin-resistant isolate (DPL20, FKS F645P). Caspofungin MICs, time-kill and postantifungal effect (PAFE) tests were performed in RPMI-1640 with and without 50 % serum. Killing rates (k values) in time-kill and PAFE experiments were determined for each strain and concentration. In time-kill experiments, colony count decreases were isolate- and concentration-dependent at 0.25, 1, 4, 8, 16 and 32 mg/L in RPMI-1640, but concentration-independent at 1, 4, 8, 16 and 32 mg/L in 50 % serum. One-hour caspofungin exposure at 4, 16 and 32 mg/L resulted in CFU decreases comparable with the results obtained in time-kill experiments in RPMI-1640, but 50 % serum at 4, 16 and 32 mg/L allowed growth of all isolates (k values were negative) (P < 0.05–0.001). PAFE in 50 % serum decreased markedly at 4, 16 and 32 mg/L. Killing rates remained high and concentration-independent in 50 % serum in case of continuous but not in case of brief caspofungin exposure. As only a short growth inhibition without killing was observed in 50 % serum, clinical relevance of caspofungin PAFE in vivo is questionable.     

Initial attachment ofCandida albicans cells to buccal epithelial cells

The rapid-freezing technique was applied in association with scanning and transmission electron microscopy to observe the initial attachment (or contact) ofCandida albicans cells to exfoliated human buccal epithelial cells. Low temperature scanning electron microscopy provided detailed three-dimensional morphological features of the yeast-epithelial cell association; adhesion ofC. albicans cells to host cells was primarily owing to an interaction between fibrillar layer of the yeast cell wall and the membrane interdigitations of the epithelial cells. Such a particular interconnection between the two cells was confirmed by the freeze-substitution fixation for transmission electron microscopy. These results clearly demonstrate the outermost fibrillar cell wall layer ofC. albicans responsible for adhesion to host cells.     

The effect of parenteral alimentation fluid,undiluted or diluted with saline or frseh sera,on the growth of Candida albicans in vitro at 37 °C

Parenteral alimentation is often complicated by Candida albicans infection which may be fatal. This study investigated the effect of alimentation fluid (Aminosol) on C. albicans' growth in vitro. It was found that concentrated Aminosol (1400 milliosmoles) maintained C. albicans in a viable state but inhibited replication. Dilution of alimentation fluid to physiological concentrations (300 milliosmoles) with either saline or aged pooled normal sera promoted in vitro growth of C. albicans which was equivalent to that obtained in BHI broth and was slightly less than that obtained in Sabouraud's broth. The effects of fresh sera with full complement activity were also investigated. In fresh sera appropriately diluted with physiological saline, some clumping of the yeasts was observed and all formed germ tubes. Growth as defined by budding or the formation of hyphae was inhibited. When Aminosol was diluted to 300 milliosmoles with fresh sera, all yeasts were noted to be in clumps with germ tubes as well as continually growing hyphae. Growth was approximately equal to that seen in Aminosol similarly diluted with saline.     

Mystery of the forbidden fruit: Historical epilogue on the origin of the grapefruit,Citrus paradisi (Rutaceae)

Attempts by the early colonial settlers of Barbados to plant orchards of shaddock (pummelo,Citrus grandis) from seedlings gave rise to the grapefruit(C. paradisi), an apomictic hybrid. Early botanists misidentified the grapefruit as a variety of shaddock, confusing it with a second hybrid growing on Jamaica. The botanist who first named the species, James Macfadyen, is shown here to have described the wrong fruit as a result of such misidentifications. Citrus historians of the 20th century have been unable to confirm the existence of a legendary Captain Shaddock, said to have brought the first seeds of the shaddock to Barbados. The present authors have found a basis for the legend, identifying a Captain Chaddock who traded in the West Indies in the 17th century. In addition, they have rectified the misidentifications of the grapefruit by early botanists that have confused the literature up to the present.     

Geographic variation in a widespread neotropical species,Mouriri myrtilloides (Melastomataceae)

Geographic variation inMouriri myrtilloides (Swartz) Poiret is analyzed on a morphological basis. Plants from Central America have medium puberulence, long calyx lobes, and short petioles and pedicels; those from Jamaica and Haiti are glabrous and have short calyx lobes, petioles, and pedicels; while those from Cuba have maximum puberulence, medium calyx lobes and pedicels, and long petioles. Glabrous or near-glabrous plants also appear rarely and more or less at random in Central and South America. Distribution in South America is limited to the northwest quarter of the continent. Most plants of this region are similar to those of Central America except that they have slightly shorter calyx lobes. However, the very short calyx lobes of plants from Jamaica and Haiti often occur in South America and rarely in Panama. Furthermore, most features of the Cuban plants appear in those of the Orinoco Basin, while individuals with one of these features, strong puberulence, are occasional elsewhere in South America. It is suggested that the complex originated in northwest South America and diversified there, subsequently radiating north and west. Considerations and problems related to such a dispersal are discussed. Taxonomically the complex is treated as consisting of four subspecies: ssp.parvifolia of Central America and much of the north-west quarter of South America, ssp.myrtilloides of Jamaica and southwest Haiti, ssp.acuta of Cuba, and ssp.orinocensis of the Orinoco Basin, the latter being a new taxon.     

Candidacidal mechanism of the arenicin-3-derived peptide NZ17074 from Arenicola marina

The candidacidal mechanisms of NZ17074, which is a variant of arenicin-3 from Arenicola marina, against human pathogenic fungus Candida albicans are reported in this work. The minimum inhibitory concentration (MIC) of NZ17074 toward C. albicans was 4 μg/ml, and this peptide exerted marked candidacidal activity in an energy-dependent and salt-sensitive manner. The flow cytometric analysis using propidium iodide (PI) showed that the plasma membrane of cells treated with NZ17074 was perturbed and that the cells were arrested in the G2/M phase. The dihydrorhodamine-123 (DHR-123) staining showed that the reactive oxygen species (ROS) production of C. albicans increased after exposure to NZ17074. Typical cellular disruption events, such as mitochondrial degradation, nuclear fragmentation, nuclear membrane disruption, and chromatin condensation, were further revealed through rhodamine 123 (RH123) staining, 4′,6-diamidino-2-phenylindole (DAPI) staining, and transmission electron microscopy. In addition, the intracellular localization of this peptide was concentration dependent: it was located in the membrane at low concentrations (4 to 8 μg/ml) and penetrated into the cytoplasm at high concentrations (16 to 32 μg/ml). Our results suggested that NZ17074 exerts its candidacidal effects by disrupting the cell membrane, inducing apoptosis, and interrupting the cell cycle. These findings showed the potential of NZ17074 as a new candidacidal peptide, in addition to its antibacterial activities.     

The effect of temperature on the development,reproduction, and longevity of two common cyclopoid copepods — Eucyclops serrulatus (Fischer) and Cyclops strenuus (Fischer)

The embryonic and postembryonic development times, time interval between clutches, and longevity of two common cyclopoid copepods — Eucyclops serrulatus and Cyclops strenuus — were studied at constant temperatures (5°, 10°, 15°, 20° and 25 °C), using algae and protozoans as food. Both, E. serrulatus and C. strenuus showed a considerable temperature tolerance and adaptability. Embryonic development times were similar in both species but postembryonic development times were shorter in E. serrulatus. Time intervals between successive clutches were relatively variable at all temperatures in both species. Longevity was shorter in E. serrulatus than in C. strenuus. The embryonic and postembryonic development of E. serrulatus was short relative to that of littoral copepods; the development of C. strenuus was similar or shorter than that of other species of the genus Cyclops.     

Detection of female plants ofPetasites fragrans and their importance for the determination of the indigenous distribution of the species

Female plants ofPetasites fragrans were detected in material imported from Algeria, and they are now cultivated in Pr?honice. Their importance for the determination of the indigenous distribution of the species was evaluated: all localities in Europe are secondary and only male plants grow there.     

Counterimmunoelectrophoresis as a routine mycoserological procedure

Counterimmunoelectrophoresis (CIE) has been compared in a diagnostic laboratory with agar gel double diffusion (DD) as a routine procedure for detection of antibodies to pathogenic and allergenic fungi and actinomycetes. It was shown to be of particular value in detecting antibodies to Aspergillus fumigatus. Thus 72 of 106 sera in which precipitins were detected were positive by CIE alone. Some sera were positive only by CIE to antigens prepared from Histoplasma capsulatum, Allescheria boydii, Candida albicans and C. parapsilosis.     

Stability and zymogenic nature of chitin synthase fromCandida albicans

Chitin synthase preparations from both yeast and mycelialCandida albicans were chiefly in a zymogenic form, activatable by trypsin treatment. This was especially marked for preparations that had been solubilized with digitonin treatment. Endogenous activation of chitin synthase zymogen was observed over many days in preparations stored in glycerol (33%, wt/v) at?12°C and over many hours in preparations stored at 30°C. Gel chromatography of enzyme preparations suggested that zymogen was preferentially retarded on the columm matrices in comparison with active enzyme.     

Relocation of Chydorus barroisi and related species (Cladocera,Chydoridae) to a new genus and description of two new species

Five taxa already in the literature are here removed from Chydorus to their own genus Ephemeroporus, and two new species — E. acanthodes and E. archboldi — are described, with E. acanthodes being designated the type species of the genus. These taxa, plus at least nine undescribed species and others undoubtedly waiting to be sorted out, constitute a tightly circumscribed group of species morphologically. The first two species described — E. barroisi and E. poppei — are nomina dubia for the present, as no specimens exist from the original collections, nor are any available from the type localities or reasonably close thereto. E. hybridus from Brazil has been characterized in greater detail through the availability of specimens from the type series, which has enabled one of the species in the E. hybridus group from North America to be judged conspecific with reasonable certainty. E. tridentatus, from Brazil, has been restored as a valid species, and the highly distinctive E. phintonicus from Sardinia and Algeria constitutes the seventh species in the genus. Chydorus nitidulus and Chydorus tilhoi, which have been suggested to be members of the barroisi complex, are not. What are presently called E. barroisi and E. hybridus, except for E. hybridus, sens. str., each consists of a cluster of species sharing the same number of teeth on the labrum and shell. Because of their wide, distribution, abundance, and frequency of occurrence, especially in South Asia, the species in the E. barroisi group will be especially meaningful to sort out.     

Comparisons of accumulation and excretion of iminosugars among mulberry-feeding specialist Bombyx larvae and non-specialist larvae

Silkworms (Bombyx mori L.) accumulate 1-deoxynojirimycin (DNJ), a mulberry iminosugar, by feeding on mulberry leaves. DNJ is a potent α-glucosidase inhibitor that helps prevent diabetes. However, iminosugars are toxic to many insects. In this study, we analyzed the concentrations of three major mulberry iminosugars—DNJ, 2-O-α-d-galactopyranosyl-DNJ (GAL-DNJ), and fagomine—in the larvae of mulberry-feeding insect species (two mulberry specialists and six non-specialists), to clarify the differences in accumulation, metabolism, and excretion of iminosugars between specialists and non-specialists. DNJ and fagomine concentrations in the two Bombyx larvae were much higher than those in the other larvae. GAL-DNJ concentrations were low in all species. DNJ and fagomine concentrations in the excrements of Agrotis segetum (Denis and Schiffermüller) and Sarcopolia illoba (Butler) larvae were lower than in those of the other larvae. Further, iminosugar concentrations in the hemolymph of B. mori, B. mandarina Moore, and S. illoba larvae were analyzed. DNJ and fagomine concentrations in the hemolymph of the two Bombyx larvae were much higher than in that of S. illoba. DNJ concentrations in the whole bodies of the two Bombyx larvae decreased as they developed. Similarly, DNJ, and fagomine concentrations in the hemolymph of B. mori larvae decreased with growth.     

Die Chromosomenzahlen von tschechoslowakischen Arten der GattungKnautia L. (Dipsacaceae)

Die Chromosomenzahlen von den tschechoslowakischen Sippen der GattungKnautia L. sind angegeben:K. drymeia Heuffel subsp.drymeia—2n = 40 (41,42),K. slovaca ?těpánek— 2n = 20,K. arvensis (L.)Coulter subsp.arvensis—2n = 20, 40 (39, 41),K. arvensis (L.)Coulter s. 1.—2n = 20,K. kitaibelii (Schult.) Borbás—2n = 20 (39, 41),K. dipsacifolia Kreutzer subsp.dipsacifolia—2n = 60,K. dipsacifolia agg.—2n = 40, 50, 60. Keine taxonomisch wertvolle morphologische Unterschiede zwischen diploiden und tetraploiden Zytotypen vonK. arvensis subsp.arvensis wurden gefunden. Für die Populationen von Pflanzen, deren Morphologierauf Kreuzung oder Introgression zwischen tetraploiden Sippen (K. arvensis subsp.arvensis—4x,K. drymeia subsp.drymeia, K. kitaibelii undK. dipsacifolia agg.) zeigt, wurden ím Einklang mit dieser Voraussetzung die tetraploiden Chromosomenzahlen—2n = 40 (39, 41)— festgestellt. Einige ungelöste taxonomische Fragen hauptsächlich über die diploiden Populationen vonK. arvensis s. l. in Böhmen und überK. dipsacifolia agg. in den Westkarpaten werden diskutiert.     

The chromosomal distribution of satellite DNA in the germ-line and somatic tissues of the gall midge,Heteropeza pygmaea

Somatic DNA from Heteropeza pygmaea separated in CsCl gradients into a main band DNA (?=1.685 g/cm³) and a satellite band (?=1.716 g/cm³) comprising 15% of the total DNA. The satellite melted sharply at 93.0°C in SSC, 10.4°C higher than the main band DNA. Satellite DNA reassociated rapidly, banding in CsCl heavier than native satellite but lighter than denatured satellite. The complementary strands of the satellite formed a single band in alkaline gradients and hence are apparently similar in G+T composition. — Filter hybridization experiments with Xenopus ribosomal RNA showed that the satellite band does not contain ribosomal cistrons. — Complementary RNA (cRNA) transcribed in vitro from isolated satellite bound extensively to satellite DNA but not to main band DNA. — The strain of Heteropeza used here contained about 58 chromosomes in germ-line cells and reproduced only paedogenetically. During early cleavage, the presumptive somatic nuclei eliminate most of their chromosomes (E-chromosomes) and retain only ten (S-chromosomes). In situ hybridizations with satellite-cRNA showed satellite DNA (prepared from predominately somatic tissues) to be localized in the centromeric heterochromatin of S- and E-chromosomes. Silver grain comparisons suggested that the amount of satellite is equivalent in both types of chromosomes. — Lastly we found that both diploid and polyploid cells contain similar amounts of satellite DNA. We interpreted this to mean that during polyploidization, as has been demonstrated during polytenization, satellite DNA does not replicate or replicates only slightly while other DNA fractions increase.