Selective medium containing fosfomycin, nalidixic acid, and culture supernatant of Rhodococcus equi for isolation of Corynebacterium pseudotuberculosis.

FNR medium containing fosfomycin, nalidixic acid, bovine blood and culture supernatant of Rhodococcus equi was prepared by the present authors, and the medium did not inhibit growth of Corynebacterium pseudotuberculosis but completely hampered the growth of Bacillus subtilis, Staphylococcus aureus, and Escherichia coli. The culture supernatant of R. equi facilitated detection of suspected colonies of C. pseudotuberculosis due to synergistic hemolysis. Rate of isolation of the organisms (from the trachea, larynx and nasal cavity of 16 slaughtered sheep with caseous abscess in the lung) was higher with FNR, the selective medium, than with nonselective medium. The selective medium was thus found to be useful for isolation of C. pseudotuberculosis from sheep.     

Biodegradation of methylthio-s-triazines by Rhodococcus sp. strain FJ1117YT, and production of the corresponding methylsulfinyl, methylsulfonyl and hydroxy analogues

A novel bacterial strain FJ1117YT was isolated from an enrichment culture with the herbicide simetryn. The isolate was capable of degrading the herbicide supplied as the sole sulfur source in an aquatic batch culture. The strain FJ1117YT was identified as that belonging to Rhodococcus sp. on the basis of comparative morphology, physiological characteristics and comparison of the 16S rRNA gene sequence. The biodegradation pathway of simetryn was established by isolating the methylsulfinyl analogue as the first metabolite and by identification of the methylsulfonyl intermediate and the hydroxy analogue by liquid chromatography-mass spectrometry (LC-MS) and/or nuclear magnetic resonance (NMR) analysis. The results indicate that the methylthio group was progressively oxidised and hydrolysed by the strain FJ1117YT. The same strain is also able to metabolise other methylthio-s-triazines such as ametryn, desmetryn, dimethametryn and prometryn through similar pathways.     

Morphology of brachial plexus and axillary artery in bonobo (Pan paniscus)

A left brachial plexus and axillary artery of bonobo (Pan paniscus) were examined, and the interrelation between the brachial plexus and the axillary artery was discussed. This is the first report of the brachial plexus and the axillary artery of bonobo. The bonobo brachial plexus formed very similar pattern to that of other ape species and human. On the other hand, the branches of the bonobo axillary artery had uncommon architecture in comparison with human case. The axillary artery did not penetrate the brachial plexus and passes through all way along anterior to the brachial plexus. Only 4.9% of human forelimbs have this pattern. Moreover, the brachial artery runs through superficially anterior to branches of the brachial plexus.     

Cryopreservation of immature oocytes of the indigeneous Vietnamese Ban Pig

We report the cryopreservation of oocytes from Ban miniature pigs which are endemic in Vietnam. Immature cumulus‐oocyte complexes were collected from antral follicles of 7–8 mo old female cyclic Ban pigs and vitrified in micro‐drops. Oocyte morphology, lipid content, post‐warming survival, nuclear maturation, and embryo development were compared to those of oocytes from commercially slaughtered Landrace × Large white hybrid pigs. The size of oocytes in the two breeds was similar. However, significantly lower amounts of intracellular lipid were detected in Ban oocytes. There was no difference (p > 0.05) between Ban and Landrace × Large white oocytes in percentages of post‐warming survival (93.1 ± 3.4% vs. 70.7 ± 16.7%, respectively) and nuclear maturation after in vitro maturation (80.4 ± 5.1% vs. 90.0 ± 1.3% respectively). Similarly, cleavage (30.8 ± 7.8% vs. 10.3 ± 6.1%, respectively) and blastocyst development rates (9.4 ± 5.0% vs. 0.79 ± 0.79, respectively) were not different (p > 0.05) between vitrified Ban and Landrace × Large white oocytes after in vitro fertilization and embryo culture. In conclusion, high survival and maturation rates were achieved after vitrification of immature Ban oocytes and their cryo‐tolerance was similar to that of Landrace × Large white oocytes, despite the difference in lipid content. We succeeded to generate reasonable rates of blastocysts from vitrified Ban oocytes by in vitro fertilization.     

The formation of apical delta of the permanent teeth in dogs

To determine the process of formation of apical delta, a histological study on the permanent teeth was carried out in dogs. A litter of 7 clinically healthy beagle dogs and 33 adult dogs (4- to 15- year-old) of 12 breeds with periodontal disease were used for the experiments. Teeth extracted from 6-,7-,8- and 9-month-old beagles were sectioned and stained with HE solution. Tooth roots obtained from adult dogs with periodontal disease were ground. Each tooth was classified into the following root types under a light microscope: Type I (no apical delta = no apical closure), II (few apical delta), IIIA (low apical delta) and IIIB (high apical delta). In the 6-month-old beagles, more than half the tooth roots were classified as type I. In the 7-month-old beagles, type IIIB apical delta was the most predominant and types I, II and IIIA apical delta were occassionally seen. Apical closure and delta were observed in all beagles at 8 months of age histologically. In the 8- and 9-month-old beagles, all root apexes observed were type IIIB. Most of the 314 tooth roots extracted from 33 adult dogs were type IIIB, but a few were type IIIA.     

Production of Ban miniature pig embryos by in vitro fertilization: A comparative study with Landrace

Ban is an endangered miniature pig breed in Vietnam. This study aimed to set up an in vitro embryo production (IVP) system for this breed. Ban's epididymal sperm concentration (1240 ± 35 × 10⁶/mL) was lower (P < 0.01) compared with Landrace (4160 ± 42 × 10⁶/mL). However, sperm characteristics before and after freezing in Ban and Landrace were similar. The numbers of follicles with diameter larger than 2 mm per ovary in Ban females treated with equine chorionic gonadotropin and human chorionic gonadotropin (27.1 ± 1.3) were higher (P < 0.05) than those in Landrace (12.9 ± 2.0) and in non‐hormone stimulated Ban (no > 2 mm follicles). After in vitro maturation, the percentages of oocytes with expanded cumulus cells and the first polar body (matured oocytes) were not different among Ban, hormone‐stimulated Ban and Landrace. The percentages of two‐cell embryos and morulae derived from oocytes collected from three sources did not differ. However, the rate of blastocysts derived from oocytes in non‐stimulated Ban (4.0 ± 3.8%) was lower (P < 0.05) than that in Landrace (15.3 ± 1.8%). In conclusion, an effective IVP system for good quality embryos in Ban, that is essential for genetic conservation of this breed, was established.     

Genetic variation in resistance of the tiger pufferfish Takifugu rubripes to a host-specific monogenean parasite Heterobothrium okamotoi

Fisheries Science - The tiger pufferfish Takifugu rubripes is one of the most valuable aquaculture species in Japan. In this study, we investigated the genetic variation in resistance to...     

Inclusion of blue mussel extract in diets based on fish and soybean meals for tiger puffer Takifugu rubripes

Inclusion of the water-soluble fraction of blue mussels Mytilus galloprovincialis as a feed additive was examined with tiger puffer Takifugu rupbripes. The control diet mainly consisted of fish meal, potato starch, and pollack liver oil. Experimental diets were formulated to replace 30% and 40% of the fish meal protein with defatted soybean meal (SBM), and were supplemented with 0–20% mussel extracts. Fish of 18 g initial body weight were fed each diet to satiation, twice daily, 6 days per week for 7 weeks at 20°C. Weight gain and protein efficiency ratio of fish fed the diet containing SBM without the extract were significantly lower than those of the control at the 30% replacement level. Addition of 5% or 10% extract improved the growth and feed utilization to levels comparable to those of the control. At 40% substitution, statistically identical growth and feed performance to the control were obtained for diets supplemented with 10% or 20% extract; however, performance for 5% addition was significantly lower. Thus, the water-soluble fraction of blue mussels would be an effective feeding stimulant in aquaculture feed for tiger puffer that makes it possible to replace 30–40% of fish meal protein with SBM.     

Pharmacokinetics of Eugenol in Japanese Flounder,Paralichthys olivaceus

Eugenol, which has been used as an anesthetic for fish, was administered to Japanese flounder, Paralichthys olivaceus (127 ± 50.8 g), by bath treatment at concentrations of 0.025, 0.125, and 0.25 mL/L seawater for 10 min and intramuscular injection at 40 μL/fish to investigate the pharmacokinetic characteristics of eugenol in the plasma of Japanese flounder. In the bath treatment test, plasma eugenol concentration increased with increasing eugenol concentration up to 0.125 mL/L and reached steady state within 5 min. After a 10‐min bath treatment in 0.25 mL/L eugenol, plasma eugenol concentration was about 58.4 µg/mL. After transfer into running seawater, plasma eugenol concentration decreased biphasically with half‐lives of 0.0296 h (α‐phase) and 0.289 h (β‐phase). The AUC_0000→0800 was about 16.5 µg h/mL. In administration by intramuscular injection, plasma eugenol concentration increased rapidly after administration and decreased biphasically with half‐lives of 0.0329 h (α‐phase) and 8.08 h (β‐phase). The AUC_0000→0800 was about 52.5 µg h/mL. In both methods of administration, Japanese flounder with average weight of 127 g were effectively anesthetized when plasma eugenol concentrations were between 2.19 and 4.88 µg/mL.     

Growth of Tiger Puffer, Takifugu rubripes, at Different Salinities

Two 12‐wk rearing experiments were conducted to examine the effect of rearing salinities of 10–35 ppt on the growth of 3‐ and 170‐g‐size tiger puffer, Takifugu rubripes. Fish were reared in a closed recirculation system without introducing fresh culture water at 23 C and were fed commercial pellet diet for tiger puffer twice or three times daily to apparent satiation each, almost everyday. Growth of 3‐g‐size fish seemed to increase with decreasing salinity; however, there were no significant differences in the specific growth rate and weight gain among treatments because of differences in initial body weight. Final body weight and length of fish reared at 10 ppt were significantly higher than those for fish reared at 30 ppt although initial sizes were similar. Differences were not found for the feed efficiency (FE) and daily feed consumption. Apparent relationships were not observed between salinity and blood characteristics or proximate compositions of muscle of the cultured fish. Differing from smaller fish, growth of 170‐g‐size fish tended to decrease with decreasing salinity from 30 to 10 ppt and with increasing salinity from 30 to 35 ppt. Similar trends for FE were observed.