Association between antimicrobial treatment and resistance of pathogenic Escherichia coli isolated from diseased swine in Kagoshima Prefecture,Japan

Pathogenic Escherichia coli is an important cause of diarrhea, edema disease, and septicemia in swine. In Japan, the volume of antimicrobial drugs used for animals is highest in swine, but information about the prevalence of antimicrobial-resistant bacteria is confined to apparently healthy animals. In the present study, we determined the O serogroups, virulence factors, and antimicrobial resistance of 360 E. coli isolates from swine that died of disease in Kagoshima Prefecture, Japan, between 1999 and 2017. The isolates of the predominant serogroups O139, OSB9, O149, O8, and O116 possessed virulence factor genes typically found in diarrheagenic E. coli. We further found five strains of third-generation cephalosporin-resistant E. coli that each produced an extended-spectrum β-lactamase encoded by bla_CTX-M-14, bla_CTX-M-15, bla_CTX-M-24, bla_CTX-M-61, or bla_SHV-12. In 218 swine with a clear history of antimicrobial drug use, we further analyzed associations between the use of antimicrobials for the treatment of diseased swine and the isolation of resistant E. coli. We found significant associations between antimicrobial use and selection of resistance to the same class of antimicrobials, such as the use of ceftiofur and resistance to cefotaxime, cefazolin, or ampicillin, the use of aminoglycosides and resistance to streptomycin, and the use of phenicols and resistance to chloramphenicol. A significant association between antimicrobial use and the resistance of E. coli isolates to structurally unrelated antimicrobials, such as the use of ceftiofur and resistance to chloramphenicol, was also observed.     

Mechanism of Pseudoalbinism in Flatfish: An Association Between Pigment Cell and Skin Differentiation

Two groups of flounder P. olivaceus larvae were reared under different conditions to provide either normally pigmented or pseudoalbinic metamorphosed juveniles. The process of the differentiation of skin and pigment cells during postembryonic development was analyzed by means of histological, histochemical and immunofluorescent assay methods. In parallel with these assays, the differentiation of pigment cells was examined with the use of organ and cell culture in vitro . The results obtained strongly suggested that pseudoalbinism was evoked as a result of disruption of the mechanisms that controlled the establishment of asymmetric skin structures during metamorphosis.     

Etiolated growth in relation to energy reserves and winter survival in three temperate grasses

The role of energy reserves in development of winter hardiness was examined in timothy (Phleum pratense L.), orchardgrass (Dactylis glomerata L.) and perennial ryegrass (Lolium perenne L.) through periodically measuring etiolated growth (EG; shoot growth of crown under dark, warm and humid conditions following defoliation) and determining sugar profiles at critical stages of hardening and wintering. Seasonal changes in weight and duration of EG were monitored by sampling once or twice a month from September to the following April. In all species, total etiolated growth (TEG; total shoot production at each sampling time as determined by weekly or biweekly harvests until exhaustion of reserves) increased from September to reach peak levels during the second hardening stage in mid-November. Thereafter, TEG remained high until the following spring in orchardgrass while it declined linearly in timothy, which had the lowest TEG. The decline in TEG was intermediate in perennial ryegrass. Changes in the duration of EG were most marked in orchardgrass, as it required six weeks to produce about 150 mg g^-1 TEG in early November but only one week in March. The results indicated occurrence of dormancy in apical meristems of orchardgrass at the end of the first hardening stage with temperatures above 0 ^°C, which roughly corresponded with the phase of dormancy in woody plants. Dormancy was weak in timothy and largely undetectable in perennial ryegrass, as measured by the EG technique. A positively significant correlation between total nonstructural carbohydrates (TNC) content and TEG was found in all species. Detailed analysis, however, showed that direct estimation of TNC content using TEG was difficult because TEG production per unit TNC was negatively correlated with TNC level, and the amount of TNC unused in early autumn was more than in the rest of the season. Changes in sugar profiles occurred at transition from the first to the second hardening stage with subzero temperatures and varied with wintering strategy of each species. Simple sugar content dramatically declined while fructan content increased in both timothy (cv. ‘Senpoku’) and orchardgrass (cv. ‘Wasemidori’), which were selected at sites covered with snow for more than 120 days. In contrast, a cold tolerant perennial ryegrass cv. `‘éveille’ selected in the Netherlands retained high amounts of simple sugars. The results suggest that EG technique is suitable to monitor physiological status (amount and rate of mobilization of energy reserves, intensity of dormancy and bud development) of plants expressing winter hardiness. This revised version was published online in July 2006 with corrections to the Cover Date.     

Heading behaviour in Japan of Turkish populations of cocksfoot,Dactylis glomerata L.

Summary Ninety-nine populations of cocksfoot collected throughout Turkey were examined for heading behaviour at Sapporo, Japan. In some populations, all the plants produced heads in the year of sowing or in the aftermath of the next year. Much of the Turkish populations, even from the mountainous regions with severe winters, is also distinct in heading behaviour in autumn from the north European types, which fail to head in the year of sowing. This behaviour is related to winter temperatures of the place of origin, with the milder winter tending to result in a higher heading rate. Date of heading is also influenced by the climatic factors of the habitat, especially by the length of the growing period between winter and summer dormancies. Turkish populations provided useful material for the study of flowering habit.     

Effect of pH Conditions on Actual and Apparent Fluoride Adsorption by Biochar in Aqueous Phase

Biochar is a carbon-rich product derived from biomass through pyrolysis. Fluoride adsorption potential of the biochar derived from orange peel (OP) and water treatment sludge (WS) at different pyrolytic temperatures (400, 600, and 700?°C) was investigated in a batch mode as a function of pH. With respect to adsorption, two types were considered, i.e., actual and apparent adsorption where fluoride combined with metal complexes in solution were counted and not counted, respectively. The highest actual fluoride adsorption was observed in the pH range of 2.0 to 3.9 for OP biochar and 5.1 to 6.2 for WS biochar, respectively. For the WS biochar, apparent fluoride adsorption showed nearly 100?% in the pH range of 2.0 to 4.5, and then the adsorption capacity diminished drastically as the pH increased from 5.0 to 10.0. There was no significant difference between apparent and actual fluoride adsorption for OP biochar. In the Fourier-transform infrared spectroscopic analysis of WS biochar, a strong and sharp band was observed at around 2,364?cm^?1 after adsorption of fluoride. Elemental content analysis by the energy-dispersive X-ray method revealed that the fluorine content was higher at pH 6.0 than at pH 3.0 and 9.0 as the results of actual fluoride adsorption. From these results, we may conclude that the biochar derived from OP and WS can be reused as an economical and effective adsorbent for fluoride removal in acidic aqueous phase.     

Decreasing dietary lipids improves larval survival and growth of Japanese eel Anguilla japonica

Shark eggs-based diet is the only diet by which eel larvae can grow to glass eels in captivity. However, the high level of lipids in the diet is suggested to negatively affect eel larvae. This paper examines the effect of defatted shark eggs (DSE) and hen egg yolk (HY) on growth and survival of larvae of Japanese eel Anguilla japonica. Lyophilized shark egg and commercial HY were defatted with n-hexane, and four experimental diets were prepared using both defatted and untreated shark eggs and HY. Larvae were reared for 3 weeks by feeding the experimental diets. The highest survival rate was observed in the larvae fed DSE, and larvae fed HY showed the lowest survival rate. The best growth was found in larvae fed DSE, followed by shark eggs and defatted HY, and the worst growth was in HY-fed larvae. These results show that decreasing dietary lipids improves the nutritional value of both shark eggs and HY for eel larvae. Regulation of the dietary lipid level may positively affect the larval performance of eels by combination of ingredients with a low lipid content.     

Different cross-reactivity of human and rodent sera to Tula virus and Puumala virus

Tula virus (TULV) and Puumala virus (PUUV) are hantaviruses carried by the bank vole (Myodes glareolus) and European common vole (Microtus arvalis), respectively. PUUV is a causative agent of hemorrhagic fever with renal syndrome (HFRS), while TULV is thought to be apathogenic to humans. The N-terminal regions of the N proteins from TULV and PUUV were expressed and applied as enzyme-linked immunosorbent assay (ELISA) antigens. Colonized Japanese grass voles (Microtus montebelli) and BALB/c mice were used for experimental inoculation of the vole-borne hantaviruses TULV and PUUV. Voles and mice showed significant antibody production toward both viruses, but these antisera showed little cross-reactivity between TULV and PUUV in the immunofluorescence antibody assay and ELISA. In contrast, sera from patients with HFRS caused by PUUV exhibited high cross-reactivity against the TULV antigen, and sera from a natural rodent reservoir showed moderate cross-reactivity against the heterologous antigen, indicating that the antigenic cross-reactivity between TULV and PUUV differs in sera from rodents and humans.