No abstract

Nematodes infections are responsible for debilitating conditions and economic losses in domestic animals as well as livestock and are considered an important public health problem due to the high prevalence in humans. The nematode resistance for drugs has been reported for livestock, highlighting the importance for development of new anthelmintic compounds. The aim of the current study was to apply and compare fluorimetric techniques using Sytox and propidium iodide for evaluating the viability of C. elegans larvae after treatment with anthelmintic drugs. These fluorescent markers were efficient to stain larvae treated with ivermectin and albendazole sulfoxide. We observed that densitometric values were proportional to the concentration of dead larvae stained with both markers. Furthermore, data on motility test presented an inverse correlation with fluorimetric data when ivermectin was used. Our results showed that lower concentrations of drugs were effective to interfere in the processes of cellular transport while higher drugs concentrations were necessary in order to result in any damage to cell integrity. The methodology described in this work might be useful for studies that aim to evaluate the viability of nematodes, particularly for testing of new anthelminthic compounds using an easy, economic, reproducible, and no time-consuming technique.

We have studied the influence of substrate temperature on the Hurst and growth exponents of CdTe thin films grown on glass substrates covered by fluorine doped tin oxide. The sample roughness profile was measured with a stylus profiler at different growth times and substrate temperatures in order to determine the critical exponents. The Hurst exponent increases linearly from 0.72 to 0.8, whereas the growth exponent increases exponentially from 0.14 to 0.62, for temperatures between 150 and 300°C. The global roughness also increases with growth temperature, which turns to be a very good parameter for roughness control.

Angiostrongylus vasorum is a nematode that parasitizes domestic dogs and wild canids. We compared the predatory capacity of isolates from the predatory fungi Duddingtonia flagrans (AC001), Monacrosporium thaumasium (NF34), Monacrosporium sinense (SF53) and Arthrobotrys robusta (I31) on first-stage larvae (L1) of A. vasorum under laboratory conditions. L1 A. vasorum were plated on 2% water-agar (WA) Petri dishes marked into 4 mm diameter fields with the four grown isolates and a control without fungus. Plates of treated groups contained each 1000 L1 A. vasorum and 1000 conidia of the fungal isolates AC001, NF34, SF53 and I31 on 2% WA. Plates of the control group (without fungus) contained only 1000 L1 A. vasorum on 2% WA. Ten random fields (4 mm diameter) were examined per plate of treated and control groups, every 24 h for 7 days. Nematophagous fungi were not observed in the control group during the experiment. There was no variation in the predatory capacity among the tested fungal isolates (P>0.05) during the 7 days of the experiment. There was a significant reduction (P < 0.05) of 80.3%, 74.5%, 74.2% and 71.8% in the means of A. vasorum L1 recovered from treatments with isolates AC001, NF34, SF53 and I31, respectively, compared to the control without fungi. In this study, the four isolates of predatory fungi were efficient in the in vitro capture and destruction of A. vasorum L1, confirming previous work on the efficiency of nematophagous fungi in the control of nematode parasites of dogs and as a possible alternative method of biological control.

The predatory capacity of the nematophagous fungus Pochonia chlamydosporia (isolate VC4) embedded in sodium alginate pellets after passage through the gastrointestinal tract of horses was assessed in vitro against Oxyuris equi eggs. Twelve previously dewormed crossbred mares, average weight of 362.5kg (+/-21) were used in the experiment. Each animal of the treated group received an oral dose (100g) of sodium alginate pellets containing P. chlamydosporia mycelial mass. The control group received pellets without fungus. Faecal samples from fungus-treated and control groups were collected at intervals of 8, 12, 24, 36, 48 and 72h after pellet administration and placed in Petri dishes containing 2% water-agar. One thousand eggs of O. equi were plated in Petri dishes of both treated and control groups, with six replicates, and incubated in oven, 25 degrees C, in the dark, for 30 days. At the end of the experiment, one hundred eggs were removed from each Petri dish and classified according to the following parameters: type 1, physiological and biochemical effect without morphological damage to eggshell, with hyphae adhered to the shell; type 2, lytic effect with morphological change in the eggshell and embryo without hyphal penetration, and type 3, lytic effect with morphological change in the eggshell and embryo, with hyphal penetration and internal egg colonization. Chlamydospore production was observed in Petri dishes of the treated group. The isolate VC4 remained viable after passing through the gastrointestinal tract of horses and maintained the ovicidal activity against O. equi eggs when compared with the control group (p<0.01) after each collection interval: 29.1% (8h), 28.2% (12h), 31.1% (24h), 27.4% (36h), 30.9% (48h) and 28.4% (72h). The results suggest that P. chlamydosporia could be used as an effective biological control agent of O. equi eggs in natural conditions.

10Pochonia chlamydosporia (Pc), a nematophagous fungus and root endophyte, uses 11 appressoria and extracellular enzymes, principally proteases, to infect the eggs of plant 12 parasitic nematodes (PPN). Unlike other fungi, Pc is resistant to chitosan, a deacetylated 13 form of chitin, used in agriculture as a biopesticide to control plant pathogens. In the 14 present work, we show that chitosan increases the incidence and severity of 15 Corresponding author: nuria.escudero@ua.es 28

The aims of this study were to test the action of the fungal extract of Pochonia chlamydosporia (VC4) on the hatching of cyathostomin eggs plated in Petri dishes containing 2% water-agar (2% WA) and its enzymatic activity in fecal cultures, in two experimental assays (A and B). The fungus P. chlamydosporia (VC4) was cultured in Erlenmeyer flasks (250ml) containing 50ml of liquid minimal medium supplemented with 0.2% gelatin for production of the crude enzymatic extract. Approximately 1kg of fresh feces was collected directly from the rectum of crossbred horses naturally infected with cyathostomins. The fecal material was used to obtain eggs and prepare fecal cultures. For assay A, one thousand eggs were plated on 4.5cm diameter Petri dishes together with 5ml of VC4 fungal filtrate and incubated at 26 degrees C in the dark for 24h. The control group consisted of 1000 eggs in Petri dishes containing 10ml of distilled water, which were incubated under the same conditions. After 24h, the total number of cyathostomin larvae present in each plate of the treated and control groups was counted. For assay B, about 20g of feces were added with 10ml of fungal extract of P. chlamydosporia (VC4) and incubated at 26 degrees C for 8 days. Third stage larvae (L(3)) were recovered at the end of this period. Significant difference (p<0.01) was found for the number of larvae between the treated group and the control at end of assay A. A 72.8% reduction in the hatching of cyathostomin eggs was found in the plates of the treated group compared with the control group. At the end of 8 days, the fungal extract of P. chlamydosporia (VC4), in assay B, was effective in reducing the number of L(3) cyathostomins in the treated group by 67.0% compared with the control group. Significant difference (p<0.01) was found between the means of L(3) recovered from the treated group and the control group. The results of this work showed that crude enzymatic extract of P. chlamydosporia (VC4) was effective in reducing hatching of cyathostomin eggs and therefore could be used as a biological control agent of this nematode.

CdTe films grown on glass substrates covered by fluorine doped tin oxide by Hot Wall Epitaxy (HWE) were studied through the interface dynamical scaling theory. Direct measures of the dynamical exponent revealed an intrinsically anomalous scaling characterized by a global roughness exponent α distinct from the local one (the Hurst exponent H), previously reported [Ferreira et al., Appl. Phys. Lett. 88, 244103 (2006)]. A variety of scaling behaviors was obtained with varying substrate temperature. In particular, a transition from a intrinsically anomalous scaling regime with H = α < 1 at low temperatures to a super-rough regime with H = α > 1 at high temperatures was observed. The temperature is a growth parameter that controls both the interface roughness and dynamical scaling exponents. Nonlocal effects are pointed as the factors ruling the anomalous scaling behavior.