Genotoxic Effects of Aluminum on the Neotropical Fish Prochilodus lineatus

Applying an integrated approach using the Comet, micronucleus (MN), and random amplified polymorphic DNA (RAPD) assays, occurrence of erythrocytic nuclear abnormalities (ENAs) and the liver activity of antioxidants enzymes (catalase and glutathione-S-transferase (GST)) was carried out to evaluate the effects of acute (6, 24, and 96 h) and subchronic (15 days) exposures to aluminum on fish Prochilodus lineatus. The Comet assay showed that fish erythrocytes exhibited significantly higher DNA damage after 6 and 96 h of Al exposure. MN frequencies were very low and did not increase significantly after Al exposures, while ENAs frequency increased significantly after all exposure periods. RAPD profiles obtained with DNA from fish fins collected before the toxicity tests were compared to the profiles with DNA from gills and liver of the same fish sampled after Al exposures. Alterations in RAPD profiles, including appearance and disappearance of bands, after 6 h, 24 h, and 15 days of Al exposure were detected. Fish exposed to Al for 6 and 24 h also showed significant increases in GST and catalase activities. These results indicated that Al exposure was genotoxic to P. lineatus, inducing DNA damage in peripheral erythrocytes. The induction of antioxidant enzymes might be an indication that Al causes oxidative damage to DNA, while the very low frequency of MN suggests that Al does not produce clastogenic or aneugenic effects. Genotoxic effects after 15 days of Al exposure was revealed only by RAPD, showing that this assay represents a sensitive method to detect genotoxic damage, occasionally not detected by other genotoxic tests used in toxicological genetics studies.     

Litter quality and decomposition of Vitis vinifera L. residues under organic and conventional farming systems

In viticulture, residue decomposition may be important in terms of fertilization, due to the low grapevine nutritional demands. Grapevine residue quality, mass loss and nutrient release rates were studied in an organic (Vorg) and a conventional vineyard (Vconv) for 19-months. Leaf and cane residues of the Vorg (Lorg, Corg) and of Vconv (Lconv, Cconv) were buried in litterbags in both vineyards. Lorg contained in mg g^?1 526 C, 14.7 N, 1.2 P and 5.4 K; Lconv 509 C, 17.9 N, 1 P and 7.3 K; Corg 556 C, 5.7 N, 1.4 P and 6.9 K; Cconv 554 C, 7.6 N, 0.9 P and 7.7 K. Mean mass loss and N, P and K release rates (k′ = k × 10⁵) were higher in leaf (k′ = 543, 541, 448, 725) than in cane residues (k′ = 146, 90, 136, 494). In Vorg, mass loss and N, P and K release rates were higher in Lconv (k′ = 904, 748, 630, 1287) than in Lorg (k′ = 293, 357, 336, 502). For Lorg, mass loss and N release rates and for Corg mass loss rate were lower in Vorg (k′ = 293, 357, 102) than in Vconv (k′ = 537, 541, 218). For Lconv, mass loss and N and K release rates were lower in Vconv (k′ = 440, 518, 557) than in Vorg (k′ = 904, 748, 1287). Incorporation of plant residues in Vconv allowed reductions of nutrient applications of 25, 2 and 21 kg ha^?1 y^?1 of N, P and K, respectively; in Vorg nutrient applications reduced by 7, 1, 5.5 kg ha^?1 y^?1.     

Biochemical characterisation of some non fermenting, non arginine hydrolysing mycoplasmas of ruminants

The pattern and kinetics of substrate oxidation by type and recent field strains of Mycoplasma agalactiae, Mycoplasma bovis, Mycoplasma bovigenitalium and Mycoplasma ovine/caprine serogroup 11 were investigated by measurement of oxygen uptake. Metabolism of a range of organic acids, sugars and alcohols was detected. All the test strains were unable to oxidise sugars, glycerol and the organic acids, fumarate, malate and alpha-ketoglutarate (1 mM). All strains oxidised organic acid l-lactate, 2-oxobutyrate and pyruvate and demonstrated the ability to oxidise alcohols, particularly isopropanol, which was oxidised at a high rate and high affinity (0.5 mol/mol isopropanol). Its oxidation was consistent with acetone formation, which may be of important in relation to pathogenicity. All strains oxidised similar substrates, however differences were observed between strains in terms of the relative rates and kinetic values for some substrates.     

Molecular characterization of Mycobacterium tuberculosis complex isolates from wild ungulates in south-central Spain

The role of European wild ungulates in the epidemiology of tuberculosis (TB) is still under discussion. This study describes the geographical distribution and molecular typing of 77 Mycobacterium tuberculosis complex isolates belonging either to M. bovis or to M. caprae, cultivated from hunter harvested red deer (Cervus elaphus) and European wild boar (Sus scrofa) in 24 Spanish localities, and compares them with spoligotypes detected previously in humans, livestock or wild animals, as described in the literature. The distribution of the molecular type patterns suggests that the population of M. tuberculosis complex strains isolated from Spanish wild ungulates is spatially structured despite the lack of important geographical barriers and despite the increasingly frequent wildlife translocations. Red deer and the European wild boar can share the same molecular types in localities in which the M. tuberculosis complex was isolated from both species. Strains of bovine and caprine origin do circulate in the same local wildlife populations. Six out of 11 spoligotypes were similar to types described in human cases. The isolation of TB strains in fenced estates from wild animals that have not had contact with domestic livestock for at least the past two decades, strongly suggests that the M. tuberculosis complex is able to survive in these populations. Therefore, wildlife including cervids and the wild boar need to be considered in the epidemiology and control of tuberculosis.     

Vegetative Compatibility and Mycotoxin Chemotypes among Fusarium graminearum (Gibberella zeae) Isolates from Wheat in Argentina

Gibberella zeae (anamorph Fusarium graminearum) is the main pathogen causing Fusarium head blight of wheat in Argentina. The objective of this study was to determine the vegetative compatibility groups (VCGs) and mycotoxin production (deoxynivalenol, nivalenol and 3-acetyl deoxynivalenol) by F. graminearum populations isolated from wheat in Argentina. VCGs were determined among 70 strains of F. graminearum isolated from three localities in Argentina, using nitrate non-utilizing (nit) mutants. Out of 367 nit mutants generated, 41% utilized both nitrite and hypoxanthine (nit1), 45% utilized hypoxanthine but not nitrite (nit3), 9% utilized nitrite but not hypoxanthine (NitM) and 5% utilized all the nitrogen sources (crn). The complementations were done by pairing the mutants on nitrate medium. Fifty-five different VCGs were identified and the overall VCG diversity (number of VCGs/number of isolates) averaged over the three locations was 0.78. Forty-eight strains were incompatible with all others, thus each of these strains constituted a unique VCG. Twenty-two strains were compatible with other isolates and were grouped in seven multimembers VCGs. Considering each population separately, the VCG diversity was 0.84, 0.81 and 1.0 for San Antonio de Areco, Alberti and Marcos Juarez, respectively. Toxin analysis revealed that of the 70 strains of F. graminearum tested, only 90% produced deoxynivalenol, 10% were able to produce deoxynivalenol and very low amounts of 3-acetyldeoxynivalenol. No isolate produced nivalenol. The results indicate a high degree of VCG diversity in the F. graminearum populations from wheat in Argentina. This diversity should be considered when screening wheat germplasm for Fusarium head blight resistance.     

Influence of dietary phospholipids on early ontogenesis of fish

The aim of this paper is to provide explanations of how dietary phospholipid (PL) globally improves fish larval development, including growth and survival, digestive functions and skeletal development, and to propose optimal PL levels and sources in fish larval diets. Dietary incorporation of 8–12% PL related to dry matter (d.m.) promotes growth and enhanced survival in various species. Marine source PL, incorporating highly unsaturated fatty acids, was most efficient than soybean lecithin. This beneficial effect was explained by an enhancement in digestive functions, assessed by digestive enzyme activities and histomorphology. Nevertheless, 1.5–2.5% highly unsaturated fatty acids related to diet d.m. supplied by PL improved growth, survival and skeletal development, while 5% induced different skeletal deformities. The high incidence of deformities was associated with the down-regulation of genes involved in development, such as RXRα, RARα, RARβ and BMP-4, observed in the early stages in larvae fed a high highly unsaturated fatty acids level.     

Freshness and quality criteria of iced farmed Senegalese sole (Solea senegalensis)

Senegalese sole (Solea senegalensis) is a high-value commercial species with increasing importance in aquaculture. The aim of this work was to study the quality changes of this species during chilled storage under refrigeration, through sensory and chemical methods. In particular, the optimization of a quality index method (QIM) scheme was proposed as well as the definition of sensory and chemical quality criteria. A shelf life of 15 days was reported, and a QIM scheme based on a total of 22 demerit points (dp) was proposed. Biogenic amines were never detected, and the usual spoilage indicators, such as TVB-N and TMA-N, were not significantly produced during the period of sensory-acceptable quality (15 days). On the basis of the significant correlations (p<0.001) between sensory data and Ki values, a quality index (QI) 19 dp and a Ki>40% indicate unacceptable quality of iced Senegalese sole.     

Deployment of Sawdust as Substrate Medium in Hydroponically Grown Lettuce

In this study, lettuce plants were grown in sawdust (Saw) and/or perlite (Per) mixtures (sawdust; Saw:Per 75:25%; Saw:Per 50:50%; Saw:Per 25:75%; Perlite) and in Nutrient Film Technique (NFT), in an unheated greenhouse. Plants grown in NFT were taller with greater leaf area resulting in greater fresh weight. Sawdust addition reduced leaf length, leaf area and as a consequence the fresh weight but not the leaf number. However, leaf dry weight increased as sawdust content increased into the substrate. Leaf chlorophyll reduced but leaf fluoresces increased in perlite and NFT. High sawdust content (75% or 100%) reduced photosynthetic rates and stomatal conductance. Nutrient uptake [potassium (K), sodium (Na), phosphorus (P)] was the greatest in NFT treatment, while perlite and Saw:Per 25:75% increased elemental uptake (up to 74%) comparing with the remaining treatments. Leaf elemental analysis fluctuated among treatments. Thus, low content (i.e. 25%) of sawdust in perlite could improve inorganic substrate media properties.     

Salmonella isolated from individual reptiles and environmental samples from terraria in private households in Sweden

Background

This study investigates Salmonella spp. isolated from privately kept reptiles and from environmental samples such as bedding materials or water from the floor of the enclosures (terraria). It also compares isolation of Salmonella using Modified Semisolid Rappaport-Vassiliadis (MSRV) medium or selective enrichment in Rappaport-Vassiliadis-Soya (RVS) pepton broth. Cloacal swabs or swabs from the cloacal area were collected from 63 individual reptiles belonging to 14 households. All reptiles were from different terraria and from 62 of these, environmental samples were also collected. Sampling were done by the reptile owners according to written instructions and sent by mail immediately after sampling. All but three samples were analyzed within 24 h after collection. Colonies suspected for Salmonella were tested for agglutination and serotyped using the White-Kauffmann-Le Minor scheme. The relative sensitivity (se) and specificity (sp) for MSRV compared with RVS, and the agreement coefficient kappa (κ) were calculated.

Results

Salmonella was isolated from 50/63 (80%) terraria, either from the reptiles (31/63; 49%) or from bedding material (39/62; 63%). The most common subspecies was Salmonella enterica subspecies enterica followed by S. enterica subspecies diarizonae. In reptiles, the most common S. enterica subspecies enterica serovars were Java (n = 4) and Fluntern (n = 4), compared with the serovars Tennessee (n = 10) and Fluntern (n = 10) in the environmental samples. The exact same set of Salmonella subspecies and serovars were not isolated from the individual reptiles and the environmental samples from any of the households. Isolation using MSRV yielded more Salmonella isolates 61/113 (54%) than enrichment in RVS 57/125 (46%). The se was 97.9% (95% Confidence Interval 93.9-100), the sp 78.5% (95% CI 68.5-88.5) and the κ 0.74, indicating substantial agreement between the tests.

Conclusions

Salmonella can be expected to be present in environments where reptiles are kept. This constitutes public health risks and should be considered during handling of the reptiles and during cleaning and disposal of bedding. A combination of different culturing techniques may be used to increase the isolation rate.