7 research outputs found
First report of Streptococcus parauberis in a cultured freshwater ornamental fish, the ram cichlid Mikrogeophagus ramirezi (Myers & Harry, 1948)
First paragraph: Since the first report of an outbreak of a streptococcal infection in rainbow trout (Oncorhynchus mykiss) in Japan in 1958 (Hoshina, Sano, & Morimoto,1958), streptococcosis has been responsible for significant mortalities resulting in considerable losses to the aquaculture industry (Noga,2010; Salati,2006). Numerous species from the family Streptococcaceae have been identified as aetiological agents of streptococcosis in fish (Noga,2010; Salati,2006; Toranzo, Magariños, & Romalde,2005), susceptibility to which was documented in both food (Inglis, Roberts, & Bromage,1993) and ornamental fish species (Russo, Mitchell, & Yanong,2006).Streptococcus parauberisis a coccoid, non-motile, alpha-haemolytic Gram-positive bacterium belonging to theStreptococcaceafamily (Nho etal.,2011) and has been reported as the aetiological agent of streptococcosis in a few fish species, including turbot (Scophthalmus maximus), olive flounder (Paralichthys olivaceus), sea bass (Sebastes ventricosus) and striped bass (Morone saxatilis) (Baeck, Kim, Gomez, & Park,2006; Domeénech etal.,1996; Haines etal.,2013; Mata etal.,2004; Oguro etal.,2014; Park etal.,2009).Streptococcus parauberishas been previously identified as the aetiological agent of bovine mastitis (Bradley,2002). It was formerly known asStreptococcustype II until comparative analysis of the sequence data ofStreptococcus uberistypes I and II showed that both were phylogenetically distinct, and the new speciesS.parauberiswas proposed (Williams and Collins1990)
A new immunization and treatment strategy for mouse mammary tumor virus (MMTV) associated cancers
Mouse Mammary Tumor Virus (MMTV) causes mammary carcinoma or lymphoma in mice. An increasing body of evidence in recent years supports its involvement also in human sporadic breast cancer. It is thus of importance to develop new strategies to impair the development, growth and metastasis of MMTV-associated cancers. The signal peptide of the envelope precursor protein of this virus: MMTV-p14 (p14) is an excellent target for such strategies, due to unique characteristics distinct from its regular endoplasmic reticulum targeting function. These include cell surface expression in: Murine cancer cells that harbor the virus, human breast cancer (MCF-7) cells that ectopically express p14, as well as cultured human cells derived from an invasive ductal breast carcinoma positive for MMTV sequences. These findings support its use in signal peptide-based immune targeting. Indeed, priming and boosting mice with p14 elicits a specific anti-signal peptide immune response sufficient for protective vaccination against MMTV-associated tumors. Furthermore, passive immunization using a combination of anti-p14 monoclonal antibodies or the transfer of T-cells from immunized mice (Adoptive Cell Transfer) is also therapeutically effective. With reports demonstrating involvement of MMTV in human breast cancer, we propose the immune-mediated targeting of p14 as a strategy for prevention, treatment and diagnosis of MMTV-associated cancers
Efficacy of garlic based treatments against monogenean parasites infecting the guppy (Poecilia reticulata (Peters))
Monogenean infections of commercially farmed fishes are responsible for significant economic losses. Garlic (Allium sativum) is a well-known spice which also possesses anti-microbial and anti-parasitical properties. The current work aimed to test the efficacy of garlic-based treatments against infection with monogenean sp. in the guppy (Poecilia reticulata). Clipped sections of tail fins of guppies heavily infected withGyrodactylus turnbulliwere exposed to aqueous garlic extract (7.5 to 30mLL−1) and visually observed under a dissecting microscope. Results revealed that exposure to garlic caused detachment of parasite and cessation of movement indicating death. A positive correlation was seen between garlic concentration and time to detachment and death of parasites, which, at the highest concentration of 30mLL−1, occurred at 4.1 and 8.6min, respectively. Bathing in aqueous garlic extract (7.5 and 12.5mLL−1) was tested in guppies infected withG. turnbulli. Prior acute toxicity tests revealed the maximum tolerance levels of guppies to garlic extract to be 12.5mLL−1for 1h. Bathing of infected fish in garlic extract (7.5 and 12.5mLL−1) significantly (p<0.05) reduced infection prevalence and intensity as compared to the control. Oral treatments using dry garlic powder-supplemented diet were tested on guppies infected withG. turnbulliandDactylogyrussp. Fish were fed with food containing 10% and 20% dry garlic powder for 14 days. Groups fed with garlic supplemented diets showed significantly reduced (p<0.05) mean prevalence and mean intensity of parasites as compared to the control. Dietary application of garlic did not appear to affect palatability. Fresh crushed garlic was added at a level of 1gL−1and applied as an indefinite bath for 14 days. This treatment was seen to significantly reduce (p<0.05) parasite prevalence and mean intensity as compared to the control. Histopathology revealed elevated muscular dystrophy in the 20% garlic-fed group, as compared to control. These findings demonstrate the potential of garlic as a natural alternative to currently used chemical treatments formonogeneansp. infection in the guppy
Effects of different commercial diets on growth performance, health and resistance to Tetrahymena sp. infection in guppies, Poecilia reticulata (Peters)
The effects of feeding guppy fry, Poecilia reticulata (Peters), different commercial diets from BernAqua [MeM (R=Regular, O=Ornamental and P=Premium) and experimental feed (EF] and Ocean Nutrition (ON) on growth was tested for 57days. Health status and resistance to Tetrahymena infection were analysed at the end of the trial. The highest growth was obtained in fish fed MeM Regular and MeM Premium (mean final weights of 427 and 417mg respectively). Fish fed EF had a significantly higher rate of spinal deformity (12.7%) than all other feeding groups (3.05% or less). Histological analysis revealed the accumulation of liver glycogen and/or lipid in fish from all feeding groups; fat accumulation in the abdomen was most pronounced in the EF and MeM Regular-fed fish, and muscle dystrophy was observed in ca. 50% of the fish from all feeding groups except the MeM Ornamental-fed group. The highest mortality following Tetrahymena infection occurred in fish fed EF (87%) and the lowest mortality in the MeM Ornamental-fed fish (58%). Mortalities in all other feeding groups ranged between 69% and 76%. In summary, MeM Ornamental feed provided a moderate weight gain, no muscle dystrophy, negligible deformity and the greatest resistance to parasitic infection
Predicting the impact of climate change: genomic measures of local adaptation in the Near Eastern Fire Salamander (Salamandra infraimmaculata)
The Near Eastern fire salamander (Salamandra infraimmaculata) is an endangered species in Israel and the Israeli populations occupy the southernmost, and most xeric habitats of the Salamandra genus worldwide. Due to its geographic distribution, restricted to a typical Mediterranean region, S. infraimmaculata is potentially vulnerable to strong environmental changes, such as an increase in temperature or a decrease in the water level. One main problem is that rates of climate change often exceed the rate at which many species can shift their range to find new suitable conditions, and therefore species survival will depend on phenotypic plasticity or adaptive capacity. Although species persistence and local adaptation are directly related to genetic diversity, most of the studies about climate change usually ignore genetic effects on species persistence. In our study we use a Climate Change Vulnerability Assessment to identify the most vulnerable populations of S. infraimmaculata in Israel, to prioritize conservation efforts and resources. We use population specific information on exposure, sensitivity and adaptability from 18 populations of S. infraimmaculata, incorporating estimates of adaptive potential and local adaptation. Since temperature is a parameter that affects almost every aspect of development and metabolism, we choose to estimate exposure to temperature for both larvae (data collected in the field during the whole reproductive period, November-May) and adults (data obtained from Movebank). We assess the physiological sensitivity by using the thermal development optimum (growth curves), critical thermal maximum (CTmax) and acclimation capacity values, that we experimentally obtained. To estimate the potential for each population to tolerate or adapt to climate change, we estimate the demographic adaptive capacity as number of populations and local abundance. We measure the genetic adaptive capacity using allelic richness (estimated from microsatellite data) and we are testing the different populations for local adaptation. Mapping RNA sequencing reads against the available transcriptomes for S. infraimmaculata, we look for SNPs in genes that can be important for local adaptation processes, such as genes involved in oxygen response, growth or development, energy metabolism, etc. We found about 2000 SNPs for one geographic region, and the analyses for the other regions are in progress. The identification of outlier SNPs in some populations can reveal a signal of local adaptation and shed light on the relationships of the genes involved in the adaptation process to specific environmental features. Combining exhaustive information about ecology and genetics for each population will be integral for guiding local conservation management in the most efficient way.peerReviewe
Evaluating the use of garlic (Allium sativum) for the remedy of Cryptocaryon irritans in guppies (Poecilia reticulata)
Garlic (Allium sativum) has been shown to possess antimicrobial properties against a range of diseaseâcausing agents, including fish parasites. Our study aimed to investigate the potential use of garlic as a treatment against Cryptocaryon irritans infection, using guppies (Poecilia reticulata) as the fish model. Garlic was freezeâdried, powdered, and used as it is or as an aqueous extract. The content of allicin, its main active ingredient, was 1.25 mg/g in garlic powder and 0.82 mg/ml in the aqueous extract, as determined by HPLC analysis. Aqueous garlic extract fully immobilized C. irritans theronts and protomonts within 20 and 40 min, respectively, following exposure to 5 ”l/ml. Treatment trials were performed, in which infected fish were fed with garlic powderâsupplemented feeds (5%, 10%, or 20% supplementation), bathed in garlic aqueous extract (250 or 500 ”l/L) and subjected to a combined treatment which included both feeding and bathing. Results revealed that the tested treatments failed to cure the infection, though reduction in infection intensity on the caudal fin, but not on the gills, was evident following dietary supplementation with 20% of powdered garlic in one of the trials