Biochemical and histological effects of gibberellic acid on Locusta migratoria migratoria fifth instar larvae

Experiments were conducted to assess the effect of gibberellic acid (GA₃), a plant growth regulator, on Locusta migratoria migratoria fifth instar larvae. Newly emerged larvae were exposed to various concentrations of GA₃ administered by topical application or by forced ingestion. Results showed that treated insects exhibited toxic symptoms with a dose-dependent mortality. GA₃ toxicity was also demonstrated by perturbation of the moult processes. In fact, we noted that treated insects present exuviations difficulties due to the impossibility to reject the old integuments causing mortality in the 5th instar larvae. Histological study of proventriculus revealed alterations in the epithelial cells and absence of apolysis phenomenon. Data also showed that GA₃ induced significant quantitative variation of haemolymph metabolites. These changes result in a significant decrease in the total concentration of proteins and carbohydrates and an increase in the total concentration of haemolymph lipids.     

Therapeutic Intervention with Dietary Chitosan Nanoparticles Alleviates Fish Pathological and Molecular Systemic Inflammatory Responses against Infections

Marine bio-sourced chitosan nanoparticles (CSNP) are antimicrobial and immunomodulatory agents beneficial for fish medicine. Herein, dietary CSNP was investigated for the amelioration of the systemic inflammatory responses of an induced fish model. One hundred and forty-four rainbow trout were assigned to one pathogen-free and non-supplemented group (negative control), and three challenged groups: non-supplemented (positive control), CSNP-preventive, and CSNP-therapeutic. After a feeding experiment extended for 21 days, the organosomatic indices (OSI) and molecular aspects were assessed. After a challenge experiment extended for further 28 days, CSNP-therapeutic intervention was assessed on fish survival and systemic inflammatory responses on pathology, histo-morphology, and molecular aspects. With CSNP administration, OSI nonsignificantly decreased and the relative expression of targeted inflammatory-mediator genes was significantly increased. The CSNP-therapeutic fish showed an RPS of 80% as compared to the positive control group, and CSNP-therapeutic administration retained the highest gene expression augmentation up to 28 days after the challenge. Notably, the splenic reticulin fibers framework of the CSNP-therapeutic group retained the highest integrity among the groups during the infection. After recovery, reticulin fibers density in the CSNP-therapeutic samples was significantly higher than in the negative control group, which indicates high innate immunity. Thus, CSNP showed promising biotherapeutic features enhancing fish resistance against infections.     

Fasciation in <Emphasis Type="Italic">Crassula argentea</Emphasis>: molecular identification of phytoplasmas and associated antioxidative capacity

The present study reports on phytoplasma induced fasciation in Crassula argintea (Crassulaceae). DNA was extracted from symptomless and fasciated tissues and amplified by nested PCR using universal primers P1/P7 followed by R16F2n/R16R2 produced amplicons of 1.2 Kb. The nucleotide sequence analyses of the amplicons indicated that fasciated plants were infected by phytoplasma. Phylogenetic analysis placed the Crassula fasciation phytoplasmas in 16SrII-D group. Histochemical staining for reactive oxygen species indicated that phytoplasma infected (PI) tissues possess significantly higher levels of hydrogen peroxide (H₂O₂) rather than superoxide (O₂ ^·-) as compared with symptomless tissues. PI tissues were also associated with a significant increase in antioxidant enzyme activities (catalase, peroxidase, polyphenol oxidase, and glutathione reductase) and electrolyte leakage as compared with symptomless tissues.     

Influence of carrot psyllid (Trioza apicalis) feeding or exogenous limonene or methyl jasmonate treatment on composition of carrot (Daucus carota) leaf essential oil and headspace volatiles

The effect of carrot psyllid (Trioza apicalis F?rster) feeding and limonene and methyl jasmonate (MeJA) treatments on the essential oil composition and headspace volatiles of carrot (Daucus carota ssp. sativus), cvs. Parano and Splendid, leaves was studied. Carrot psyllid feeding significantly increased the concentrations of sabinene, beta-pinene, and limonene, whereas limonene treatment increased the concentration of (Z)-beta-ocimene in the leaves of both cultivars. The limonene treatment significantly increased the concentration of total phenolics in the leaves of both cultivars, and MeJA treatment increased phenolic concentration in the leaves of Parano. Exogenous limonene spray did not decrease the number of carrot psyllid eggs laid either 2 or 24 h after treatment. The results suggest that carrot psyllid feeding induces changes in the endogenous monoterpene pool in the carrot leaves. Limonene and MeJA treatments affect some induced defenses of the carrot, but the exogenous limonene spray is not an effective oviposition deterrent against carrot psyllid.     

Effect of two species of cyanobacteria as biofertilizers on some metabolic activities, growth, and yield of pea plant

Two cyanobacterial species (Nostoc entophytum and Oscillatoria angustissima) were tested as biofertilizers, substituting the normally used chemical fertilizer, for pea plant. Inoculation of soil with a suspension of each species or a combination of the two species significantly increased the germination percentage and stimulated the other measured growth parameters and photosynthetic pigment fractions of pea. However, the soil inoculation with one cyanobacterial species and the addition of the recommended dose or half the recommended dose of chemical fertilizer were usually more effective and also increased carbohydrate and protein contents of produced pea seeds. However, biofertilization combined with half the recommended dose of the chemical fertilizer was usually more effective than the addition of the full rate of the chemical fertilizer, and this may allow saving 50% of the used chemical fertilizer. The protein profile of the produced seeds showed appearance and disappearance of some protein bands in response to fertilization treatments compared to the control. Blue green algae analyses show that N. entophytum fixed more N, produced more exopolysaccharide, and contained more auxin and cytokinin than O. angustissima, the latter contained more gibberellins. These data may explain their different influences on growth and yield of pea.     

DNA extraction from bovine mummified fetuses and detection of factor XI gene deficiency in the mummies

Genomic DNA extracted from bovine mummified tissue is valuable material for detection of some genes that may contribute to fetal abnormalities. In this study bovine genomic DNA was extracted from the hardened tissue samples of ten bovine mummified fetuses. The amount of genomic DNA extracted from 2 g of the mummified tissues by the phenol/chloroform-ethanol method was low (less than 4 microg/ml) for all samples. The extracted DNA was then amplified by the GenomiPhi DNA amplification system. After amplification, the amount of DNA was increased to more than 100 microg/ml for all samples. This amplification system was shown to be a good tool for amplifying the genomic DNA of the mummified fetuses. The amplified genomic DNA was used for testing the mummies for Factor XI gene deficiency, an autosomal recessive deficiency involved in the early stages of the intrinsic blood coagulation pathway. Exon 12 of the Factor XI gene of the mummies was amplified by PCR. Two of the ten mummified fetuses were heterozygous for the Factor XI gene as indicated by the presence of two amplified DNA fragments of 320 bp and 244 bp. Factor XI deficiency has already been described in Holstein cattle. However, no report is available for bovine fetus. In this study, DNA was extracted and amplified from the bovine mummified fetuses, and the samples were successfully tested for Factor XI gene deficiency in the mummies.     

火鸡疫病:对兽医的新挑战

现代火鸡业,定位于产量高、品质好、价格低,且要与消费者对禽肉产品的需求相一致,预防火鸡疫病以保障人类健康是现代火鸡业的导向性目标.……     

Clinicopathological and ultrasonographic findings in 40 water buffaloes (Bubalus bubalis) with traumatic pericarditis

Forty buffaloes with traumatic pericarditis were examined to characterise the ultrasonographic findings in buffaloes with traumatic pericarditis, determine the extent of the lesions and assess the prognosis. The most noticeable clinical presentations were presternal oedema (73 per cent) and jugular and mammary vein distension (88 per cent). Laboratory findings included neutrophilic leucocytosis, elevated total protein concentration, hypoalbuminaemia, hypergammaglobulinaemia and increased concentration of free fatty acids. Ultrasonographically, fluid in the pericardium appeared as either mild or massive anechoic accumulations containing fibrin threads or were imaged as homogenous, echogenic pericardial effusions. Moderate to severe corrugation of the reticular wall was observed. Deposits of fibrinous tissue interspersed with fluid pockets were seen between the reticulum, dorsal ruminal sac and diaphragm. Perireticular and mediastinal abscesses were imaged and appeared as echogenic lines with anechoic, echogenic, homogenous or heterogeneous contents. Additional ultrasonographic findings included hepatomegaly, dilation of the caudal vena cava, hepatic and portal veins, ascites, echogenic pleural effusions and vegetations of the tricuspid, mitral and pulmonary valves. The ultrasonographic findings were confirmed at postmortem examination.     

First report of <Emphasis Type="Italic">Neospora caninum</Emphasis> infection in cattle in Sudan

A cross-sectional survey was conducted in Sudan to determine sero-prevalence and risk factors associated with Neospora caninum infection in non-vaccinated dairy herds and to assess importance of the disease. Blood samples were collected from a total of 262 animals from 25 herds. Sera were tested for antibodies against N. caninum using ELISA test. The prevalence rates of N. caninum antibodies in cattle were high both at herd level (44%) and at individual animal level (10.7%). Herd level infection rates were similar in Khartoum State (43.7%) and at Gazira States (44.4%). The overall prevalence rates were higher (16.1%) in Gazira State than in Khartoum State (9%) but with no significant variation. The sero-prevalence at individual animal level was significantly higher (p < 0.05) in animals with history of abortion (12.8%) than in apparently healthy animal (11.3%), animal with history of infertility (8.1%), or neonatal death of calves (4.3%). In addition, significantly higher (P < 0.05) sero-prevalence was observed in samples collected during the rainy season (6.87%) than winter (3.05%) or summer (0.76%). However, no significant differences in sero-prevalence due to locality, animal breed, sex, and age were observed (p > 0.05). This preliminary study reveals for the first time the existence of natural N. caninum infection in Sudan. Also, the findings of the present study indicated that this disease is highly prevalent in two major areas of dairy production in the country, and this calls for control strategy to be implemented.