霉菌毒素对虾类养殖的危害

<正>养虾业目前面临的最多的问题就是疾病的广泛发生,包括寄生虫病、细菌病和病毒病。由于这些疾病经常导致严重的经济损失,所以一直是整个产业最为关注的。然而在养殖环境和饲料中还存在其它的致病因子却常被忽视,如存在于饲料中的霉菌毒     

Adiponectin and IGF-1 are negative acute phase proteins in a dog model of acute endotoxaemia

The objective of this study was to evaluate the influence of an experimentally induced acute inflammation on serum adiponectin and insulin-like growth factor 1 (IGF-1) levels in the dog, and to compare their evolution with other well-established acute phase proteins (APPs) such as C-reactive protein (CRP), and haptoglobin (Hp). Therefore levels of adiponectin, IGF-1 and a profile of APPs were measured in healthy dogs after intravenous administration of E. coli LPS (0.02 mg/kg) and compared with dogs injected with saline solution (0.2 mL/kg). Adiponectin and IGF-1 were both decreased in response to endotoxins in the dog. Significant positive correlations were found between adiponectin and IGF-1 (r=0.31; p<0.05). Adiponectin had also a significant negative correlation with CRP (r=-0.39; p<0.05) and Hp (r=-0.27; p<0.05), whereas IGF-1 had significant negative correlation with CRP (r=-0.52; p<0.001). The results obtained in the present study indicate that adiponectin and IGF-1 behave as negative acute phase proteins after acute inflammatory stimulus in dogs.     

Microarray-based genotyping of Staphylococcus aureus isolates from camels

Staphylococcus aureus is a common cause of mastitis and other diseases in camels. In order to obtain data on population structure as well as on the carriage of toxin genes and resistance markers, a collection of 45 isolates from dromedaries of Dubai, United Arab Emirates, were genotyped. These isolates belonged to clonal complexes CC6 (twenty isolates; 44.44%), CC30 (sixteen isolates; 35.56%), CC188 (five isolates; 11.11%), CC152 (1 isolate, 2.2%) and to a previously un-described sequence type (ST1755: arcc-18, aroe-115, glpf-6, gmk-2 pta-109, tpi-50 and yqil-2; three isolates; 6.67%). Resistance genes proved to be rare. Only three out of 45 isolates (6.67%) carried the beta-lactamase operon. The tetracycline resistance gene tetK was also detected in three isolates (6.67%). Neither the mecA gene, defining MRSA, nor other resistance genes were found. Common virulence markers included leukocidin genes lukD+lukE (in twenty-five isolates; 55.56%), the staphylokinase gene sak (twenty-two isolates; 48.89%), the enterotoxin gene cluster egc (fifteen isolates; 33.33%), and a distinct variant of the enterotoxin A gene (sea-320E, GenBank AY196686.1; thirteen isolates; 28.89%). One CC152 isolate was positive for genes encoding the Panton-Valentine leukocidin (lukF-PV+lukS-PV). This study provides first genotyping data on the population structure and the presence of toxin genes and resistance markers of S. aureus strains in Middle Eastern camels.     

Disseminated Rhodococcus equi infection in dromedary camels (Camelus dromedarius)

Rhodococcus (R). equi, a recognized pathogen in horses, is emerging as a human opportunistic pathogen, especially in immunocompromized people. It affects also New World camelids, but there are no reports of R. equi infection in Old World camelids yet. Four cases of disseminated R. equi infection in adult breeding dromedaries occurred at one camel farm near Dubai within 16 months of each other. At necropsy the lungs were diffusely consolidated with large caseous areas. Histology revealed severe suppurative to necrotising pneumonia with multiple encapsulated abscesses. Immunohistochemistry enabled the detection of 15- to 17-kDa antigens (VapA) of R. equi in the lung sections. High numbers of R. equi were isolated from the lung lesions as well as from liver, spleen and mediastinal lymph nodes, indicative of septicaemia. The isolated strains were PCR-positive for the specific virulence plasmid (VapA-Gen) of R. equi, indicating virulent strains and containing an 85-kb type I plasmid. This is the first report of disseminated R. equi infection in Old World camelids. Since adult camels in general do not suffer from bacterial caused pneumonia (except tuberculosis), this is a new emerging disease for camels.     

Mycoplasma ovis in captive cervids: prevalence, molecular characterization and phylogeny

Hemotrophic mycoplasmas (hemoplasmas) are bacteria that attach to red blood cells of mammals, leading to acute and/or subclinical disease in infected animals. It has been suggested that Mycoplasma ovis, a hemoplasma that infects sheep and goats worldwide, may also infect deer. The aim of this study was to evaluate whether South American deer are infected with M. ovis. EDTA-anticoagulated blood samples from a herd of 32 captive South American deer were collected. DNA extraction of blood samples was performed followed by PCR amplification of the 16S and 23S rRNA genes, and sequencing of products. Using M. ovis PCR, 27/31 (87%) were positive, including 21/22 Mazama nana; 2/3 Mazama americana and 4/6 Blastocerus dichotomus. Sequencing of the nearly entire 16S rRNA gene of 26/27 positive samples showed 98.2-98.8% identity to M. ovis of sheep (GenBank, AF338268) and 98.6-99.4% identity to M. ovis-like of a fawn (FJ824847); the 23S rRNA gene from one of these isolates and the fawn's had 97.6% identity. The remaining isolate had just 94.9% identity to the 16S rRNA gene of M. ovis and only 89.4% identity to the 23S rRNA gene of the fawn's M. ovis. This is the first report of M. ovis in captive South American deer, revealing a high prevalence of hemoplasma infection in these animals.     

Proximal isovelocity surface area variability during systole in dogs with mitral valve prolapse

The proximal isovelocity surface area (PISA) principles and methodology have been described in human and veterinary medicine with special emphasis given to the ease and speed for the quantification of mitral regurgitation. Although limitations have been described in both human and veterinary medicine, in the case of veterinary medicine, clinical examples have not been well defined and in some cases have not been individually presented. The objective of this paper is to illustrate in a qualitative manner the echocardiographic existence of the dynamic behavior and variability of mitral regurgitation in dogs with mitral valve prolapse, a factor to be taken into consideration as a limitation inherent to the PISA technique.     

Assessment of mechanical ventricular synchrony in Doberman Pinschers with dilated cardiomyopathy

Objectives

Loss of temporal synchrony of myocardial contraction has been shown to reduce systolic function and be responsible for disease progression in people. The objective of this study is the assessment of inter- and intra ventricular synchrony in healthy Doberman Pinschers and those with dilated cardiomyopathy (DCM) by use of conventional Doppler and tissue velocity imaging.

Animals

A total of 60 scans from 35 client-owned Doberman Pinschers presented for cardiac evaluation were analysed.

Methods

Retrospective analysis of data. Using the European Society of Veterinary Cardiology DCM taskforce scoring system, Doberman Pinschers were classified into 4 groups: Control (Group 1; n = 12), depressed systolic function other than DCM (Group 2; n = 9), preclinical DCM (Group 3; n = 8) and symptomatic DCM (Group 4; n = 6). The time intervals between the beginning of the QRS complex and the peak velocity of pulmonic flow (Q-P) and the peak aortic flow (Q-Ao) were used to assess global synchrony between both ventricles. The time intervals between the beginning of the QRS complex and the peak myocardial systolic velocity (Q-peak S) and the onset of myocardial systolic velocity (Q-start S) were measured at the base of the right and left ventricular free wall (RVFW and LVFW) and interventricular septum (IVS), and used to determine segmental longitudinal inter- and intra ventricular synchrony.

Results

No significant loss of global or segmental longitudinal inter- or intra ventricular synchrony was identified between the groups.

Conclusion

Impairment of longitudinal fibre synchrony does not appear to be significantly associated with clinical status of DCM in Doberman Pinschers, although it was identified in certain individuals.     

Correlation between jugular and central venous pressures in laterally recumbent horses

Objective To compare and correlate right atrial pressure, which represents central venous pressure (CVP) to jugular vein pressure (JVP) in laterally recumbent horses under anesthesia. Study design Retrospective clinical trial. Animals Seven adult healthy horses (411 ± 8.7 kg). Methods Horses were sedated with IV xylazine and anesthesia was obtained with IV ketamine and diazepam. Anesthesia was maintained with sevoflurane in oxygen. All horses were positioned in left lateral recumbency. An 8F catheter introducer was inserted into the right jugular vein to measure JVP. An 8F catheter introducer was inserted into the left jugular vein to be used as the port for a 7F 110 cm catheter that reached the right atrium to measure CVP. Both, CVP and JVP were measured simultaneously with a water calibrated aneroid manometer using the sternum as the 0 cmH₂O reference point. Measurements were compared using Spearman correlation and the Bland‐Altman plot. Results Twenty paired samples were obtained over a period of 2 hours. The CVP ranged from 7 to 31 cmH₂O, while the JVP ranged from 5 to 30 cmH₂O. The Spearman correlation coefficient indicated that CVP and JVP had a strong correlation with r = 0.88. The Bland‐Altman plot showed a bias of 0.7 cmH₂O. Conclusion and clinical relevance Jugular vein pressure showed a strong correlation with CVP in healthy, euvolemic, laterally recumbent anesthetized adult horses. Thus, JVP cannot replace CVP but it may be used clinically to monitor CVP in laterally recumbent horses.     

Water relations of pistachio (Pistacia vera L.) as affected by phenological stages and water regimes

Pistachio is a drought tolerant fruit tree that can be cultivated in rainfed and irrigated conditions. The water requirements of the tree, however, are considerable so in most of the commercial orchards deficit irrigation is a common practice. Regulated deficit irrigation in pistachio trees has been described in several works, which reported that the phenological stage of shell hardening, so called stage II, is the most drought tolerant. This paper proposes that such drought resistance is related to changes in water relations linked to the phenological stages, even in conditions of no water stress. In order to evaluate such changes, the daily pattern of stem water potential and gas exchange (net photosynthesis, P_n, and leaf conductance, g_s) was measured, determining also the pressure–volume curves, in three different phenological stages of mature pistachio trees (Pistacia vera cv Kerman on P. terebinthus L. rootstock.). The daily pattern of stem water potential and gas exchange were performed in three different irrigation treatments: control, regulated deficit irrigation and rainfed. The pressure–volume curves were made only in the control and rainfed treatments. Significant differences were found in the daily pattern of stem water potential in all the phenological stages considered, while only in the last one the net photosynthesis was affected by water stress. The daily pattern of gas exchange at the beginning of the season was not affected by the evaporative demand, with a constant value when radiation was not limiting. Moderate levels of water stress during the last measurement date reduced the maximum values of g_s and P_n resulting also in a clear change in the pattern of the daily curve, with maximum values only at the beginning of the day. The relationships between stem water potential and gas exchange parameters were different during stage II and almost the same in stages I and III. The parameters drawn from the pressure–volume curves also indicated a change in the elastic modulus of the leaf cells in stage II. In addition, differences in the osmotic adjustment (OA) index suggested different degree of osmotic adjustment of the phenological stages in the response to water stress. The results showed that different mechanisms of drought resistance are operating in the different phenological stages in pistachio trees.