Immune response of sea bass <Emphasis Type="Italic">Dicentrarchus labrax</Emphasis> to <Emphasis Type="Italic">Tenacibaculum maritimum</Emphasis> antigens

ABSTRACT:   Seawater fishes are affected by a pathology commonly called 'myxobacteriosis', caused by Tenacibaculum maritimum (formerly Flexibacter maritimus ). The disease is characterized by fin erosion and necrotic ulcers of skin and muscle, and by low but constant mortality in cultured marine fish; in Italy is one of the most important and widely spread diseases affecting sea bass Dicentrarchus labrax , gilthead seabream Sparus aurata , sharp-snouted bream Diplodus puntazzo , white bream Diplodus sargus , and six-tooted bream Dentex dentex . In order to obtain an effective vaccine against the disease, formalin killed cells (FKC), extracellular products (ECPs) and crude lipopolysaccharide (LPS) preparations were obtained from the T. maritimum strain SPVId and injected intraperitoneally twice into the sea bass. The fish immune response to the preparations was studied: agglutinating antibody titer and in vitro phagocytosis were determined after the first and second injection in order to evaluate whether the preparations are immunogenic or not and if the booster effect took place. The results show that FKC and LPS preparations increased the antibody titer after the first injection when compared to the control sea bass. Moreover, all the preparations stimulated a secondary (booster) response. In vitro phagocytosis of the total blood was significantly higher for all the preparations when compared to the controls, but the crude LPS immunized sea bass showed the highest activity.     

In vitro release of angiotensin-converting enzyme inhibitors, peroxyl-radical scavengers and antibacterial compounds by enzymatic hydrolysis of glycated gluten

The combined effect of gluten glycation and proteolysis on the release of compounds exhibiting in vitro angiotensin-converting enzyme (ACE) inhibitory, antioxidant and antibacterial activities was investigated. Model systems consisting of wheat gluten and glucose were heated at 120 °C for 45 min, 150 °C for 30 min and 220 °C for 30 min to produce various Maillard reaction products mimicking reactions occurring in bread crusts. Progress of the Maillard reaction was estimated through indirect measurement of Amadori compounds as 2-furoylmethyl-amino acids. Glycation was followed by digestion with Pronase E and ultrafiltration. The anti-hypertensive activity was measured as the ability to inhibit the activity of angiotensin I-converting enzyme involved in hypertension regulation. The Oxygen Radical Absorbance assay was used to measure the peroxyl radical scavenging capacity of the products and their effect on microbial growth of Escherichia coli ATCC 25922 and Staphlococcus aureus ATCC 25923 was also studied. Advanced products of the reaction enhanced the antioxidant and antibacterial properties of gluten hydrolysates and decreased the overall ACE inhibitory activity. Ultrafiltration provided a useful method for separating compounds (< 3000 Da) with ACE inhibitory activity and advanced Maillard reaction products (>3000 Da) which scavenged peroxyl radicals and inhibited the microbial growth.     

Diagnosis of Coxiella burnetii-related abortion in Italian domestic ruminants using single-tube nested PCR

Coxiella burnetii, an obligate intracellular parasite with a worldwide distribution, is the causative agent of acute and chronic Q fever in humans. Although infection is often unapparent in cattle, sheep and goats, there is increasing evidence that C. burnetii infection in these species is associated with abortion and stillbirth. This paper describes the introduction of a single-tube nested PCR protocol for the diagnosis of C. burnetii-related abortion in domestic ruminants in Italy. A total of 514 aborted foetuses from cattle (n = 138) and sheep and goat (n = 376), collected from 301 farms, were analyzed from January 2001 to March 2005. Ninety-seven of 514 (18.9%) animals tested PCR-positive, with 16/138 (11.6%) cattle and 81/376 (21.5%) sheep and goat. Eleven of 102 (10.8%) farms with reproductive disorders in cattle and 37/199 (18.6%) farms with reproductive disorders in sheep and goats were infected with C. burnetii. A greater incidence was observed in three of the seven investigated provinces (p < 0.01), with rates of infected farms of up to 23.8%. Data showed that almost all the C. burnetii-related abortions were recorded between October and April (p < 0.01). These findings suggest that Q fever in humans is largely underestimated in Italy, probably because its occurrence is obscured by flu-like symptoms in acute forms.     

Interannual and seasonal changes in the soil exchange rates of monoterpenes and other VOCs in a Mediterranean shrubland

Information about soil VOC inventories and exchange rates in different soils is very scarce. Seasonality of soil VOC exchange rates is also largely unknown, despite the increasing interest in some soil volatile compounds, such as monoterpenes, because of their important role in soil ecology. We aimed to explore and quantify soil VOC exchange rates in a Mediterranean shrubland and their seasonality. Measurements of soil VOC exchange were taken using GC‐MS and PTR‐MS techniques, together with soil temperature, soil moisture and soil CO₂ efflux measurements, during two annual campaigns with contrasting precipitation. Methanol, acetic acid, ethyl acetate, acetaldehyde, acetone, C₃ and C₄ carbonyls (such as methyl ethyl ketone), α‐pinene and limonene, showed the highest emission rates. Maximum soil monoterpene emission rates were very low (0.003 nmol m^?2 s^?1) compared with foliar monoterpene emission rates. The emission rates of the other VOCs were also low (maximum 0.8 nmol m^?2 s^?1) except for methanol (1.2 nmol m^?2 s^?1). Maximum soil uptake rates for some VOCs, such as methanol and acetonitrile (ranging from ?0.1 to ?0.5 nmol m^?2 s^?1) were, however, comparable with foliar uptake rates. Further studies are needed to corroborate these results and the possible importance of the soil VOC sink in regional chemistry‐climate models. Long‐term severe drought increased soil monoterpene emission rates in this Mediterranean shrubland. The increases seem to be linked to changes in the soil’s physical properties induced by low soil moisture. Unlike monoterpenes, other soil VOC emission rates decreased when soil moisture was low. The results suggest a seasonal control of soil temperature on the emission rates of monoterpenes and other VOCs. The emission rates increase with soil temperature. Positive correlations between the VOC exchange rates and the soil CO₂ fluxes suggest that phenology of roots and microorganisms also controls seasonal changes in soil VOCs in this Mediterranean shrubland.     

Interannual and interseasonal soil CO2 efflux and VOC exchange rates in a Mediterranean holm oak forest in response to experimental drought

Climate models predict drier conditions in the next decades in the Mediterranean basin. Given the importance of soil CO₂ efflux in the global carbon balance and the important role of soil monoterpene and volatile organic compounds (VOCs) in soil ecology, we aimed to study the effects of the predicted drought on soil CO₂, monoterpenes and other VOC exchange rates and their seasonal and interannual variations. We decreased soil water availability in a Mediterranean holm oak forest soil by means of an experimental drought system performed since 1999 to the present. Measurements of soil gas exchange were carried out with IRGA, GC and PTR-MS techniques during two annual campaigns of contrasting precipitation. Soil respiration was twice higher the wet year than the dry year (2.27±0.26 and 1.05±0.15, respectively), and varied seasonally from 3.76±0.85 μmol m⁻² s⁻¹ in spring, to 0.13±0.01 μmol m⁻² s⁻¹ in summer. These results highlight the strong interannual and interseasonal variation in CO₂ efflux in Mediterranean ecosystems. The drought treatment produced a significant soil respiration reduction in drought plots in the wet sampling period. This reduction was even higher in wet springs (43% average reduction). These results show (1) that soil moisture is the main factor driving seasonal and interannual variations in soil respiration and (2) that the response of soil respiration to increased temperature is constrained by soil moisture. The results also show an additional control of soil CO₂ efflux by physiology and phenology of trees and animals. Soil monoterpene exchange rates ranged from −0.01 to 0.004 nmol m⁻² s⁻¹, thus the contribution of this Mediterranean holm oak forest soil to the total monoterpenes atmospheric budget seems to be very low. Responses of individual monoterpenes and VOCs to the drought treatment were different depending on the compound. This suggests that the effect of soil moisture reduction in the monoterpenes and VOC exchange rates seems to be dependent on monoterpene and VOC type. In general, soil monoterpene and other VOC exchange rates were not correlated with soil CO₂ efflux. In all cases, only a low proportion of variance was explained by the soil moisture changes, since almost all VOCs increased their emission rates in summer 2005, probably due to the effect of high soil temperature. Results indicate thus that physical and biological processes in soil are controlling soil VOC exchange but further research is needed on how these factors interact to produce the observed VOCs exchange responses.     

Milk composition,fatty acids profile and fat globule size of bottlenose dolphin (Tursiops truncatus,Montagu 1821) milk at early lactation

Veterinary Research Communications - Research data on milk composition in cetaceans are scattered and fragmentary. This paper analyses the gross and mineral composition, the fatty acids profile and...     

Identification of porcine circovirus-3 in Mozambique

Veterinary Research Communications - Porcine circovirus 3 (PCV-3) has been associated with an assortment of clinical conditions in pigs and has been reported in many countries worldwide. In Africa...     

Evaluation of Tobacco Cultivars as Bioindicators and Biomonitors of Ozone Phytotoxical Levels in Catalonia

A field study was conducted from May to October 1995 to assess ozone (O₃) phytotoxicity in Catalonia (NE Spain) by determining a percentage value of leaf area injured by ozone on three tobacco cultivars, Bel-W3, Bel-C and Bel-B as bioindicators. Colorimetric parameters were also determined in an effort to have an objective assessment of ozone injury. The study was conducted simultaneously on eight sites where ozone levels and several meteorological parameters were continuosly monitored. Two sets of plants were used at each site. The first one was composed of six plants of each cultivar which were changed every two weeks while the second one involved two plants of each cultivar which were kept in the plots throughout the whole experimental period. Open Top Chambers were also used to test the response of the three cultivars to ozone under controlled conditions. The ozone levels correlated well with ozone injury on the Bel-W3 cultivar but not as well on the other two cultivars. The ozone levels did not fully account for all the observed injury. The response of tobacco plants to ozone concentrations and therefore its biomonitoring capacity depended also on different environmental conditions linked to stomatal behaviour such as temperature, humidity, wind or altitude. These environmental conditions had some effects on the intensity of Ozone injury. Ozone concentrations accumulated over a threshold of 60 ppb (AOT60) when VPD was below 1 KPa. Correlated well with the ozone injury and best explained the intensity tobacco injury symptoms. For large plants growing throughout the whole period of study, Bel-C was the best indicator cultivar for AOT60 over the 3 days prior to the last ozone injury assessment. The colorimetric parameters were indicators of seasonal changes but they were not good ozone damage indicators. It is concluded that tobacco cultivars were good bioindicators but meteorological and other environmental factors need to be considered in there use as biomonitors.