Effect of Compost Properties on Progress Rate of Verticillium dahliae Attack on Eggplant (Solanum melongena L.)

Several composts were tested for their capacity to moderate the effect of Verticillium dahliae Kleb. (VCG B4, VD) on eggplant (Solanum melongena) under greenhouse conditions. Eggplants plantlets were inoculated by immersing their roots in conidial suspension and then planted in pots filled with mixtures of compost or peat moss, mixed with perlite. Six composts and peat moss mixtures were tested, of which tomato waste compost suppressed V. dahliae, and turkey litter compost partially suppressed it. Reduced levels of symptoms and lower fungal colonization were detected in the xylem of eggplants planted in tomato waste compost, and these plants accumulated more dry matter and had higher chlorophyll content compared to other media. However, survival of conidia in tomato waste compost showed only a moderate decrease compared with a sharp decrease in other media, suggesting that conidial eradication cannot be proposed as the suppressiveness mechanism. γ irradiation of tomato waste compost and peat at 2.5 Mrad reduced microorganism density by four orders of magnitude, but irradiation of tomato waste compost did not reduce its suppressiveness of V. dahliae. Composts properties affected progress rate of VD in the xylem tissue of eggplant seedling. These properties could indicate both biotic and abiotic factors affecting the process.     

Survival,persistence and proliferation of Vibrio anguillarum in juvenile turbot,Scophthalmus maximus (L.), intestine and faeces

The aim of this study was to determine whether orally administered V. anguillarum cells could survive passage through the intestinal tract of feeding turbot, and thereafter, proliferate in the released faeces. In addition, the growth of the pathogen in turbot faeces in the presence of a Carnobacterium sp. with inhibitory effects against a number of bacterial fish pathogens was studied. It was found that V. anguillarum cells survived the acidic environment of the stomach for several hours, persisted in the intestine and readily proliferated in the released faeces. The antagonistic Carnobacterium sp. inhibited the growth of V. anguillarum during co-culture in turbot faecal extracts. From the results, it was concluded that the turbot intestinal tract and faeces can serve as an enrichment site for V. anguillarum, and the use of intestinal bacteria with antagonistic activity against vibrios may be used to reduce the load of fish pathogenic vibrios in turbot hatcheries.     

Growth and economic performance of Nile tilapia (Oreochromis niloticus L.) fed on two formulated diets and two locally available feeds in fertilized ponds

Lack of suitable diets for semi‐intensive production of Oreochromis niloticus in Kenya has necessitated use of expensive diets designed for intensive production. To address this problem, two isonitrogenous (24% protein) diets were formulated and evaluated for production of O. niloticus in fertilized ponds. One diet contained vitamins and minerals premix (CV) while the other had no premix (CW). Growth of fish fed on the formulated feeds was compared with groups of fish fed on commercial pig pellets (PP) and wheat bran (WB). There were significant differences in mean weights, growth rates and feed conversion ratios between the formulated and the other diets. No significant differences in these parameters were observed between CV and CW and also between PP and WB. Fish that fed on the formulated feeds produced significantly lower number of juveniles than those fed on PP and WB. Fish fed on WB gave the best economic returns while those on PP had the least returns. Present results suggest that vitamins and minerals premix may not be necessary in diets for semi‐intensive production of O. niloticus. Present results showed that the formulated feeds produced higher yields than PP and WB, but WB had the best economic returns among the test diets.     

Is the turbot,Scophthalmus maximus (L.), intestine a portal of entry for the fish pathogen Vibrio anguillarum?

The role of the intestinal tract in Vibrio anguillarum infection of turbot, Scophthalmus maximus (L.), fingerlings was investigated in two in vivo models and the possible mechanisms involved were studied in vitro. Viable V. anguillarum cells were detected in spleens from more than 50% of the fish administered the pathogen orally or rectally, suggesting that the intestinal tract is a portal of entry for V anguillarum. In transmission electron micrographs, V. anguillarum- like cells were seen close to the rectal epithelium, suggesting penetration of the mucus layer, but no epithelial cell penetration or endocytosis was evident. Attachment to intact turbot intestines was investigated, and 80% or more of the bacterial cells still remained attached after serial washings. A significantly higher number of cells attached to rectal segments than to the other intestinal segments. In vitro, V. anguillarum cells did not adhere specifically to intestinal mucus, but rather accumulated close to intestinal mucus interfaces and subsequently penetrated them. It is proposed that the intestinal ttact of tutbot is a portal of entry for V. anguillarum and that the cells penetrate the intestinal mucus overlaying the epithelial cells.     

Infecting Pacific Herring with Ichthyophonus sp. in the Laboratory

The protistan parasite Ichthyophonus sp. occurs in coastal populations of Pacific Herring Clupea pallasii throughout the northeast Pacific region, but the route(s) by which these planktivorous fish become infected is unknown. Several methods for establishing Ichthyophonus infections in laboratory challenges were examined. Infections were most effectively established after intraperitoneal (IP) injections with suspended parasite isolates from culture or after repeated feedings with infected fish tissues. Among groups that were offered the infected tissues, infection prevalence was greater after multiple feedings (65%) than after a single feeding (5%). Additionally, among groups that were exposed to parasite suspensions prepared from culture isolates, infection prevalence was greater after exposure by IP injection (74%) than after exposure via gastric intubation (12%); the flushing of parasite suspensions over the gills did not lead to infections in any of the experimental fish. Although the consumption of infected fish tissues is unlikely to be the primary route of Ichthyophonus sp. transmission in wild populations of Pacific Herring, this route may contribute to abnormally high infection prevalence in areas where juveniles have access to infected offal.

Received June 25, 2015; accepted September 12, 2015     

Impact of heat stress on germinal vesicle breakdown and lipolytic changes during in vitro maturation of bovine oocytes

Two studies were conducted with the overarching goal of determining the extent to which lipolytic changes relate to germinal vesicle breakdown (GVBD) in bovine oocytes matured under thermoneutral or hyperthermic conditions. To this end, cumulus-oocyte complexes underwent in vitro maturation for 0, 2, 4, 6 or 24 h at 38.5 (first study) or 38.5 and 41.0 C (second study; heat stress applied up through first 12 h only, then shifted to 38.5 C). Independent of maturation temperature, triglyceride and phospholipid content decreased markedly by 2 h of in vitro maturation (hIVM; P < 0.0005). Content was lowest at 24 hIVM with no detectable impact of heat stress when exposure occurred during first 12 hIVM. Germinal vesicle breakdown occurred earlier in oocytes experiencing heat stress with effects observed as soon as 4 hIVM (P < 0.0001). Germinal vesicle breakdown was associated with lipolytic changes (R² = 0.2123 and P = 0.0030 for triglyceride content; R² = 0.2243 and P = 0.0026 for phospholipid content). ATP content at 24 hIVM was higher in oocytes experiencing heat stress (P = 0.0082). In summary, GVBD occurs sooner in heat-stressed oocytes. Although marked decreases in triglyceride and phospholipid content were noted as early as 2 hIVM and preceded GVBD, lipolytic changes such as these are not likely serving as an initial driver of GVBD in heat-stressed oocytes because changes occurred similarly in oocytes matured at thermoneutral conditions.     

COMPARISON OF LUNG ATTENUATION AND HETEROGENEITY BETWEEN CATS WITH EXPERIMENTALLY INDUCED ALLERGIC ASTHMA,NATURALLY OCCURRING ASTHMA AND NORMAL CATS

Airway remodeling is a prominent feature of feline allergic asthma but requires biopsy for characterization. Computed tomography (CT) has appeal as a minimally invasive diagnostic test. The purpose of this prospective case–control study was to compare indices of airway remodeling between cats with experimentally induced, spontaneous asthma and healthy unaffected cats using CT. We hypothesized that experimental and spontaneous feline asthma would have similar CT airway remodeling characteristics and that these would be significantly different in healthy cats. Experimentally induced asthmatic research cats (n = 5), spontaneously asthmatic pet cats (n = 6), and healthy research cats (n = 5) were scanned unrestrained using a 64‐detector row CT scanner. Inspiratory breath‐hold CT scans were also performed in experimentally induced asthmatic and healthy cats. Mean ± extent variation of lung attenuation for each cat was determined using an airway inspector software program and CT images were scored for lung heterogeneity by a board‐certified veterinary radiologist who was unaware of cat group status. Groups were compared using one‐way ANOVA (unrestrained scans) and the Student's t‐test (anesthetized scans) with significance defined as P < 0.10. Experimentally asthmatic and spontaneously asthmatic cats had significantly (P = 0.028 and P = 0.073, respectively) increased lung attenuation compared to healthy cats. Heterogeneity scores were higher in experimentally induced asthmatic cat than in healthy cats. Objective quantification of lung heterogeneity and lung volume did not differ among the three groups (P = 0.311, P = 0.181, respectively). Findings supported our hypothesis. Inspiratory breath‐hold anesthetized CT scans facilitated discrimination between asthmatic and healthy cats in comparison to unrestrained CT scans.     

Experimental infection of Swiss webster mice with four rat bartonella strains: host specificity, bacteremia kinetics, dose dependent response, and histopathology

Groups of Swiss Webster outbred mice were each inoculated with one of four bartonella strains originally isolated from Rattus spp. at doses ranging from 10¹ to 10⁷ bacteria per mouse. One strain, Rn1691yn (Bartonella coopersplainensis-like), infected mice and produced bacteremias at levels up to 10⁵ bacteria/ml of blood and from 3 to 8 weeks duration. A dose dependent response was also observed with differing proportions of mice bacteremic following inoculation at different doses. In addition weeks-to-months long lags in bacteremia manifestation occurred following lower dose exposures. The possibility of bacterial transmission from bacteremic mice to uninfected cagemates was assessed and no naïve mice became infected from contacts with infected mice. Finally, a subset of bacteremic mice inoculated with high doses of Rn1691yn were examined histopathologically and multifocal, granulomatous lesions were detected in both liver and kidneys. The host specificity and infectivity of the strains is discussed in relation to their potential for zoonotic transmission to incidental hosts.     

Treatment of Bilateral Medial Femoral Condyle Articular Cartilage Fissures in a Horse Using Bone Marrow-Derived Multipotent Mesenchymal Stromal Cells

The objective of this study was to describe the use, and outcome, of multipotent mesenchymal stromal cells (MSCs) in the treatment of equine articular cartilage defects of the medial femoral condyle. A 4-year-old Thoroughbred gelding (n = 1) with bilateral stifle athroscopy was found to have bilateral articular cartilage fissure defects of the medial femoral condyles with concurrent cranial cruciate ligament injury. Bone marrow derived MSCs were isolated, expanded, and suspended in a partially autologous fibrin glue. The initial cell/fibrin glue mixture was delivered arthroscopically into the articular cartilage defects 90 days after the initial arthroscopic examination. Follow-up treatments included two additional injections of MSCs suspended in lactated Ringers solution, 5 and 13 months after the initial examination, directly into the joint. Post-treatment outcome was assessed by arthroscopic examination and by comparison of preinjury and post-treatment performance records. Arthroscopic evaluation 4 months after the initial MSC treatment revealed marked smoothing, reduction in the depth of cartilage defects and observation of moderate improvement in the cranial cruciate ligament. Approximately 15 months after the initial MSC treatment the horse returned to racing. Analysis of race records demonstrated that the post-treatment (including all three MSC treatments) average race earnings (earnings per start) were comparable with those predating the initial injury. The favorable clinical response in the face of an unknown, but likely, guarded prognosis suggest that MSC therapy is not deleterious and may augment healing of articular cartilage fissures of the medial femoral condyle. MSCs represent a viable and promising alternative therapy in the treatment of articular cartilage injuries in performance horses.