First report of ophidiomycosis in Asia caused by Ophidiomyces ophiodiicola in captive snakes in Japan

Ophidiomycosis is an emerging infectious disease caused by the fungus Ophidiomyces ophiodiicola, which has been affecting wild and captive snakes in North America, Europe, and Australia. We report 12 cases of suspected ophidiomycosis in captive colubrid snakes in Japan. Pathological and microbiological examinations were performed, and the results confirmed the diagnosis of ophidiomycosis in two snakes, which indicated that the remaining sympatrically raised snakes also had ophidiomycosis since they exhibited similar lesions. This is the first report of ophidiomycosis in Asia caused by O. ophiodiicola. To prevent the expansion of ophidiomycosis in the natural environment in Japan, there is a need to evaluate the ophidiomycosis carrier status of imported snakes, the pathogenicity of the infection in native snakes, and the prevalence and distribution of O. ophiodiicola in wild and captive snakes. Measures also must be taken to prevent endemicity globally.     

Evaluation of the Cranial Cruciate Ligament Repair System? in Surgery for Laryngeal Hemiplegia in Heavy Draft Horses

The purpose of this study was to evaluate the effect of the canine cranial cruciate ligament repair system on laryngeal hemiplegia in heavy draft horses. Twenty-four heavy draft horses diagnosed with grade 4 laryngeal hemiplegia were allocated to either the prosthetic laryngoplasty (PL) group (n=14) or a canine cranial cruciate ligament repair system (CCCLRS) group (n=10). Right to left angle quotients (RLQs) of abductions of the arytenoid cartilages were endoscopically evaluated before and after surgery. Post-operative RLQs in the CCCLRS group were significantly lower than those of the PL group (P<0.01). The canine cranial cruciate ligament repair system was revealed to be a good surgical procedure for laryngeal hemiplegia in heavy draft horses.     

Propagation of Asian isolates of canine distemper virus (CDV) in hamster cell lines

Backgrounds

The aim of this study was to confirm the propagation of various canine distemper viruses (CDV) in hamster cell lines of HmLu and BHK, since only a little is known about the possibility of propagation of CDV in rodent cells irrespective of their epidemiological importance.

Methods

The growth of CDV in hamster cell lines was monitored by titration using Vero.dogSLAMtag (Vero-DST) cells that had been proven to be susceptible to almost all field isolates of CDV, with the preparations of cell-free and cell-associated virus from the cultures infected with recent Asian isolates of CDV (13 strains) and by observing the development of cytopathic effect (CPE) in infected cultures of hamster cell lines.

Results

Eleven of 13 strains grew in HmLu cells, and 12 of 13 strains grew in BHK cells with apparent CPE of cell fusion in the late stage of infection. Two strains and a strain of Asia 1 group could not grow in HmLu cells and BHK cells, respectively.

Conclusion

The present study demonstrates at the first time that hamster cell lines can propagate the majority of Asian field isolates of CDV. The usage of two hamster cell lines suggested to be useful to characterize the field isolates biologically.     

Distribution and stem growth patterns of mangrove species along the Nakara River in Iriomote Island, Southwestern Japan

We examined variations in stand structure and tree growth of a mangrove forest along two gradients: from the river mouth to upper stream and from the riverside to inland, along the Nakara River, Iriomote Island, Japan. Bruguiera gymnorrhiza (L.) Lamk. occurred throughout the intertidal area, though Rhizophora stylosa Griff. and Kandelia candel (L) Druce did not occur upstream. Basal area and maximum tree height of B. gymnorrhiza decreased downstream. The growth rate in stem diameter of B. gymnorrhiza decreased downstream in relation with the soil salinity. The basal area and the maximum tree height of B. gymnorrhiza increased with the distance from the riverside. R. stylosa increased in stem diameter and growth rate toward the riverside.     

A newly devised electric field screen for avoidance and capture of cigarette beetles and vinegar flies

A bifunctional electric field screen was proposed to physically exclude insect pests from warehouses. The screen consists of insulated iron wires (ICW) arranged in parallel and two earthed conductor nets placed on both sides of the ICW. A negative charge (0.1-8.0 kV) was applied to the insulated wires with a voltage generator to polarize an insulator sleeve used to cover the wire, negatively on the outer surface and positively on the inner conductor wire surface of the sleeve. The negative surface charge of the ICW caused an electrostatic induction in the earthed nets and an opposite charge on the net surfaces facing the ICW. An electric field formed in a space between the ICW and the earthed net, and the field strength increased in direct proportion to increasing voltages applied to the ICW. Adults of the test insects (cigarette beetle (Lasioderma serricorne) and vinegar fly (Drosophila melanogaster)) reaching the outer surface of the earthed net were deterred from entering the inside of the charged screen, whereas all insects immediately passed through the screen when the ICW was not charged. This avoidance was directly proportional to the increase in the voltage. In addition, the capability of the screen to capture insects that enter inside the screen was proven by introducing insects into the space between the ICW and the earthed net. Strong capture was observed when the ICW was negatively charged with more than 4.1 kV, under which conditions a short-term electric current (peaking at 0.3-0.6 μA, for 3 min) occurred transiently. This electric current was due to the release of electricity from the insects, giving a net overall positive charge to the insects, which therefore were attracted more strongly to the negatively charged ICW. A test using an attractant-set chamber showed that the insects were completely prevented from passing through the charged screen, in contrast to a rapid transfer of all insects when the screen was not charged. Thus, the present results show that the described screen is a promising physical tool for controlling insect pests in warehouses.     

Effect of flexible and rigid roughness elements on aeolian sand transport

In developing countermeasures to reduce the negative effects of strong dust events, the fundamental relationship between surface conditions and sand transport remains problematic. We conducted field observations and wind tunnel experiments to examine the effect on sand transport efficiency of actual frontal area when using flexible roughness elements (artificial grass) and rigid roughness elements (tufts of stiff wire). In the field observations, the sand trap ratio approached a limit as the frontal area of artificial grass, measured as the Actual Frontal Area Index (AFAI), approached 25%, equivalent to a vegetation cover of 20%. The wind tunnel experiments showed that the height of deposited sediment decreased downwind with both roughness elements, due to their reduction of both shear velocity and sand transport rates. The sediment flux decreased as the AFAI increased, and the rigid roughness element trapped more sand particles than the flexible one except at higher wind speeds and lower AFAI values. The sand trapping efficiency was greater for rigid roughness elements than for flexible ones, probably due to their high aerodynamic resistance, and thus wire tufts were more effective for trapping sand than artificial grass at higher AFAI values.     

Effect of timing and type of supplementary grain on herbage intake,nitrogen utilization and milk production in dairy cows grazed on perennial ryegrass pasture from evening to morning

The present study aimed to clarify the effect of timing and type of supplementary grain in grazing dairy cows on herbage dry matter intake (HDMI), nitrogen utilization and milk production. Eight lactating cows were allowed to graze from evening to morning during three seasonal periods (spring, summer, autumn). They were randomly allocated to four treatments (timing: pre‐ (Pre) or post‐grazing (Post), for large grain allotments consisting of 75% of daily grain offered; grain type: barley or corn) in 4 × 4 Latin square designs in each period. In the spring period, HDMI was greater for cows fed corn than those fed barley (P = 0.005), whereas cows in the Pre treatment had a similar HDMI, higher (P = 0.049) urinary purine derivative concentration and greater (P = 0.004) milk yield compared with cows in the Post treatment. In the summer and autumn periods, timing treatments did not affect HDMI, nitrogen utilization or milk production, but cows supplemented with barley had higher urinary purine derivatives concentration (P < 0.05) and milk yield (P < 0.05) compared with those supplemented with corn. The results indicate that large grain allotments immediately before evening grazing during early grazing seasons increased ruminal microbial protein synthesis and milk production without reducing HDMI regardless of grain type.     

Frequent use of colistin-based drug treatment to eliminate extended-spectrum beta-lactamase-producing <Emphasis Type="Italic">Escherichia coli</Emphasis> in backyard chicken farms in Thai Binh Province,Vietnam

Reports of livestock infections with extended-spectrum beta-lactamase-producing Escherichia coli (ESBL-E) are increasing. Based on interviews conducted over a 6-month period, we found that veterinarians in the Vietnamese province of Thai Binh prefer to prescribe colistin-based drugs (CBD) in chicken farms. We aimed to clarify whether CBD use selects for strains of colistin-resistant ESBL-E. With the cooperation of seven local households, we detected ESBL-E in chickens’ feces after treating chickens with CBD. Phylogenetic groupings and the presence of CTX-M/AmpC genes were determined, and the multi-antibiotic susceptibility of isolates was analyzed. Our results showed that ESBL-E presented in seven chickens’ feces from two households. Seventy-two percent of ESBL-E isolates harbored CTX-M9 and the phylogenetic group A; the colistin minimum inhibitory concentration (MIC) of all isolated ESBL-E ranged from 0.064 to 1 μg mL^?1. Moreover, ESBL-E isolates were used to experimentally select for colistin resistance, and the effect of commercial CBD on ESBL-E was investigated. The results showed that an ESBL-E strain with a colistin MIC of 4 μg mL^?1 was able to grow in media with CBD. Although CBD treatment was effective, in vitro experiments demonstrated that ESBL-E can easily acquire colistin resistance. Therefore, restrictions on colistin use are necessary to prevent the emergence of colistin-resistant bacteria.     

Winter nitrate uptake by the temperate deciduous tree <Emphasis Type="Italic">Quercus serrata</Emphasis>

Winter nitrogen use in deciduous species is largely uncharacterized. We investigated nitrate uptake in the fine roots of a deciduous oak (Quercus serrata Thunb. ex. Murray). We conducted a ¹⁵N-labeling experiment using saplings of Q. serrata in the winter. During three weeks of labeled nitrate application, the concentration of ¹⁵N in the fine roots increased significantly. The amount of nitrogen absorbed, as nitrate, was 1.16 ± 1.02 mg N g DW⁻¹, equivalent to 7.6 ± 5.8% of the total nitrogen content. Our results indicate that Q. serrata saplings have significant potential for nitrate uptake in the fine roots in midwinter (i.e., in the absence of leaves). Although a significant amount of nitrogen applied as nitrate was accumulated, nitrate concentration in the fine roots remained low during the labeling period. Furthermore, significant nitrate reductase activity was detected. These data suggest that Q. serrata saplings can assimilate nitrate in the fine roots in midwinter.