Homeopathic complex increases survival without affecting the performance of Nile tilapia during masculinization

During the masculinization of Nile tilapia, Oreochromis niloticus, the effect of a homeopathic complex (containing Chamomilla, Quina, and sulphur) was evaluated based on survival, performance, gills and liver integrity, and parasitism. Group fed with basal diet + 17 alpha-methyltestosterone (control) showed low survival (40.02%), while the group that additionally received homeopathy and the group that received sucrose (vehicle) showed 73.7% and 87.7% survival, respectively. The growth performance of the group that received homeopathic and the control group was significantly higher than that of the group that received only sucrose. Still, fish that received the homeopathic complex showed higher branchial and hepatic integrity as compared to the other groups. The homeopathic complex contributes to a greater survival of fish in addition to maintaining satisfactory growth. Furthermore, homeopathy contributes to the improvement in gill and liver integrity of the Nile tilapia larvae.     

Three strategic feeding during hatchering of Nile tilapia: effects on organs integrity,parasitism and performance parameters

The effect of natural feed, artificial feed, and artificial feed with hormone 17 alpha-methyltestosterone on gill and liver integrity, parasite prevalence and performance parameters during the masculinization phase of Nile tilapia Oreochromis niloticus were evaluated. The experiment consisted of the three feeding strategies in triplicate. Water parameters, histopathological, parasitological and performance analyses were performed on day 7, 14, 28 and 60. Both artificial feeds (with and without hormone) were harmful to the hepatic and branchial integrity. The most significant change in liver was lipid degeneration, while in gills a significantly higher lamellar edema was observed when compared to fish that received the natural feed. Fish fed with the artificial diet (with and without hormone) showed a high prevalence (p < 0.05) of trichodinids and Cryptobia, while fish that received natural feed showed no parasites after 28 days of study. Fries that received diet with hormone experienced damage to their health, which decreased the survival of this group. The anabolic effect of this molecule, however, improved significantly (p < 0.05) their productive performance. Despite the absence of deleterious effects to fish health, the use of natural feed has a high risk of introducing predators. Introduction of odonate larvae drastically affected the survival of this group at the end of the study. All feeding strategies investigated have positive and negative effects that were discussed in the present study.     

Phylogenetic Analyses of Phytopathogenic Isolates of Verticillium spp

ABSTRACT To better understand the genetic relationships between Verticillium dahliae isolates from lettuce and other phytopathogenic Verticillium spp. isolates from various hosts and geographic locations, the complete intergenic spacer (IGS) region of the nuclear ribosomal RNA gene (rDNA) and the beta-tubulin gene were amplified and sequenced. The sequences of the complete IGS region and the beta-tubulin gene were used alone and in combination to infer genetic relationships among different isolates of Verticillium with the maximum-likelihood distance method. Phylogenetic analyses set sequences into four distinct groups comprising isolates of V. albo-atrum, V. tricorpus, and V. dahliae from cruciferous and noncruciferous hosts. Within the four Verticillium groups, isolates of V. dahliae from cruciferous hosts displayed the closest affinity to V. dahliae from noncruciferous hosts. Isolates of V. dahliae from noncruciferous hosts could be further divided into four subgroups based on sequence similarities within the IGS region. Cross-pathogenicity tests demonstrated that most Verticillium isolates were as virulent on other hosts as on their hosts of origin. A phenogram based on the cross pathogenicity of individual isolates resembled those derived from the IGS and beta-tubulin sequence comparisons. On the basis of the data presented, the potential origin of some isolates of V. dahliae pathogenic on lettuce is proposed.     

Phytotherapy as an alternative for treating fish disease

Intensification of livestock rearing often promotes an increase in inappropriate practices that disregard care for the environment, animal health, and workers' health. Intensive fish farming systems are often associated with higher stocking density and massive use of artificial feed. Currently, outbreaks of parasitic, bacterial, and fungal diseases act as major limiting factors for fish farming, meaning that producers have to make use of massive amounts of antibiotics, disinfectants, and pesticides in order to control mortality and avoid huge economic losses. Because of adverse effects on the aquatic environment, terrestrial organisms, and human health (both fish handlers and consumers), this therapy has been criticized. Use of herbal medicines within animal production has shown promise, in that it is natural and biodegradable and has antimicrobial activity against various pathogens, including those relating to fish. Recently, researchers have reported promising effects from many herbal medicines for treating parasitic diseases caused by protozoa and metazoa, and broad activity against bacteria and fungi. This review addresses the current issues regarding indiscriminate use of chemicals and antibiotics in aquaculture and discusses the main findings and methodologies of the latest research on herbal medicines to stimulate and accelerate research in this field, especially in developing countries.     

Predictive factors for the regression of canine transmissible venereal tumor during vincristine therapy

Canine transmissible venereal tumor (CTVT) is a neoplasm transmitted by transplantation. Monochemotherapy with vincristine is considered to be effective, but treatment time until complete clinical remission may vary. The aim of this study was to determine which clinical data at diagnosis could predict the responsiveness of CTVT to vincristine chemotherapy. One hundred dogs with CTVT entered this prospective study. The animals were treated with vincristine sulfate (0.025 mg/kg) at weekly intervals until the tumor had macroscopically disappeared. The time to complete remission was recorded. A multivariate Cox regression model indicated that larger tumor mass, increased age and therapy during hot and rainy months were independent significant unfavorable predictive factors retarding remission, whereas sex, weight, status as owned dog or breed were of no predictive relevance. Further studies are necessary to investigate whether these results are due to changes in immunological response mechanisms in animals with a diminished immune surveillance, resulting in delays in tumor regression.     

Practical diets with essential oils of plants activate the complement system and alter the intestinal morphology of Nile tilapia

The effect of the essential oils (EOs) of peppermint, Mentha piperita L., and tea tree, Melaleuca alternifolia (Maiden & Betche) Cheel, on the haematological, biochemical, and immunological parameters and intestinal morphology of Nile tilapia, Oreochromis niloticus L., was evaluated. Fish (58.09 ± 5.87 g) were fed 100 mg/kg and 250 mg/kg of each EO and sampled on days 7, 14, 30 and 60 after starting supplementation. The haematological and biochemical parameters were not altered by the supplementation of EOs compared to the control (p > .05). With regard to the immunological parameters, the activation of the complement system of fish fed 250 mg/kg peppermint and 100 mg/kg and 250 mg/kg tea tree EOs were significantly higher compared to the control after 60 days of feeding (p < .05). The complement system plays an essential role in innate immunity and contributes significantly to the acquired immune response; thus, its activation through supplementation with EOs is promising for the formulation of nutritional additives in aquaculture. Regarding intestinal morphology, fish fed 250 mg/kg tea tree EO presented higher villus size compared to all other groups (p < .05), which represents a healthier gut. These fish present a larger intestinal surface, which can result in better absorption and utilization of the nutrients. Based on the responses found in this study, both EOs were considered promising for the formulation of feed additives for Nile tilapia.     

Phylogenetic network analysis of South and North American Corynespora cassiicola isolates from tomato,cucumber, and novel hosts

European Journal of Plant Pathology - Corynespora cassiicola isolates display morphological, pathogenic, and ecological diversity, inducing target spot-like diseases in more than 500 hosts...     

Colonization of resistant and susceptible lettuce cultivars by a green fluorescent protein-tagged isolate of Verticillium dahliae

Interactions between lettuce and a green fluorescent protein (GFP)-expressing, race 1 isolate of Verticillium dahliae, were studied to determine infection and colonization of lettuce cultivars resistant and susceptible to Verticillium wilt. The roots of lettuce seedlings were inoculated with a conidial suspension of the GFP-expressing isolate. Colonization was studied with the aid of laser scanning confocal and epi-fluorescence microscopes. Few differences in the initial infection and colonization of lateral roots were observed between resistant and susceptible cultivars. Hyphal colonies formed on root tips and within the root elongation zones by 5 days, leading to the colonization of cortical tissues and penetration of vascular elements regardless of the lettuce cultivar by 2 weeks. By 8 to 10 weeks after inoculation, vascular discoloration developed within the taproot and crown regions of susceptible cultivars well in advance of V. dahliae colonization. Actual foliar wilt coincided with the colonization of the taproot and crown areas and the eruption of mycelia into surrounding cortical tissues. Advance colonization of stems, pedicels, and inflorescence, including developing capitula and mature achenes was observed. Seedborne infection was limited to the maternal tissues of the achene, including the pappus, pericarp, integument, and endosperm; but the embryo was never compromised. Resistant lettuce cultivars remained free of disease symptoms. Furthermore, V. dahliae colonization never progressed beyond infected lateral roots of resistant cultivars. Results indicated that resistance in lettuce may lie with the plant's ability to shed infected lateral roots or to inhibit the systemic progress of the fungus through vascular tissues into the taproot.