Evaluation of the low dose level of a heat-killed and dried cell preparation of Enterococcus faecalis to prevent porcine edema disease using experimental infection model with enterotoxcemic Escherichia coli in weaning pigs

Porcine edema disease (ED) is caused by Shiga toxin 2e-producing Escherichia coli (STEC). ED has become frequent in pig farms, and the use of antimicrobials has resulted in the development of antimicrobial-resistant STEC. Accordingly, the use of materials other than antimicrobials is requested for the prevention of ED. Oral administration of a heat-killed and dried cell preparation of Enterococcus faecalis strain EC-12 (EC-12) to weaning pigs was previously demonstrated to decrease animal mortality in a STEC-contaminated farm at 0.05% (w/w) dose level. In this study, pigs experimentally infected with STEC were used as a model for ED to evaluate the low dose level of EC-12 to prevent ED. Fifteen 21-day-old pigs were divided into 5 groups: STEC challenge with the basal diet, STEC challenge with EC-12 supplemented at 0.005, 0.01, or 0.05% (w/w) to the basal diet, and no STEC challenge with the basal diet. The challenge was carried out when the animals were 25, 26, and 27 days old using STEC contained in capsules resistant against gastric digestion. All pigs were euthanized at 32 days of age. The daily weight gain, feed conversion ratio, and palpebral edema were improved by supplementation with 0.05% EC-12, but not by the low dose levels. Accordingly, 0.05% level of supplementation was needed for EC-12 to improve clinical symptoms in weaning piglets infected by STEC.     

Relationship of glomerular filtration rate based on serum iodixanol clearance to IRIS staging in cats with chronic kidney disease

We examined the correlation between the glomerular filtration rate (GFR) estimated from an equation based on the serum iodixanol clearance technique and International Renal Interest Society (IRIS) stages of chronic kidney disease (CKD) in cats. The equation included the injection dose, sampling time, serum concentration and estimated volume of distribution (Vd) of the isotonic, nonionic, contrast medium iodixanol as a test tracer. The percent changes in the median basal GFR values calculated from the equation in CKD cats resembled those of IRIS stages 1–3. These data validate the association between the GFR derived from the simplified equation and IRIS stages based on the serum creatinine concentration in cats with CKD. They describe the GFR ranges determined using single-sample iodixanol clearance for healthy cats and cats with various IRIS stages of CKD.     

Arrhythmogenic right ventricular cardiomyopathy coincided with the cardiac fibrosis in the inner muscle layer of the left ventricular wall in a boxer dog

A 7-year-old female boxer dog died suddenly without any clinical signs. It was suspected that the dog had arrhythmogenic right ventricular cardiomyopathy (ARVC) due to ventricular premature complexes and ventricular tachycardia at 3 years of age. The final diagnosis of ARVC was confirmed by histological characteristics, such as loss of cardiocytes and fibrofatty replacement, occurring in the right and left ventricular walls. In the cardiocytes, non-lipid vacuoles were observed. Cardiac fibrosis and intimal thickening of the small arteries occurred without fatty replacement in the inner muscle layer including the papillary muscles of the left ventricular wall. This paper describes the pathomorphological details of an ARVC case with coincidental cardiac fibrosis in the inner muscle layer of the left ventricular wall.     

利用聚合酶链式反应技术研究单粒古代稻谷(公元800年)离体DNA片段的扩增

在东南亚地区已发掘出很多古代稻谷,如果能从这些古稻谷中把DNA提出加以分析,可以得到有关栽培稻的系统分化和地理传播方面的直接信息。古代稻种的基因型相当复杂,必须要能从单粒种子开始分析,方能得到有价值的资料。为此,我们进行了从单粒古稻谷中提取DNA的研究工作。本研究采用通常提取植物组织中DNA的方法。从在日本挖掘出的古代稻谷单粒种子中提取出了50—100ng左右的DNA片段。以这些DNA作为模板,用聚合酶链式反应(Polymerase Chain Reaction,PCR)技术将DNA加以扩增。由其中几个DNA片段初步合成了相当于水稻光敏色素基因的DNA序列。     

Transcellular penetration of Treponema phagedenis isolated from papillomatous digital dermatitis in polarized normal human epidermal keratinocytes in vitro

Papillomatous digital dermatitis (PDD) is a polymicrobial infection causing lameness in dairy cattle. Culture-independent analysis has shown that Treponema phagedenis is present consistently and predominantly in the lesions. However, the pathogenesis of PDD, especially the tissue penetration pathway, has not been examined. In the present study, we investigated whether T. phagedenis strains isolated from PDD produce proteolytic enzyme (s) for disruption of the epithelial cell barrier and have the ability to translocate in polarized normal human epidermal keratinocytes (NHEK) in vitro. Ten strains of T. phagedenis isolated from lesions did not show proteolytic activity on modified skim milk agar, although a human strain of T. denticola used as a control showed such activity. The integrity of tight junctions was monitored by measurement of transepithelial electrical resistance (TER). The TER values after inoculation of the T. phagedenis strains examined did not change during the experimental period; however, apical to basolateral translocation of T. phagedenis was confirmed after 24 hr by microscopy and Treponema-specific PCR. We further confirmed that translocation of T. phagedenis was accelerated by co-inoculation with live T. denticola, but not with heat-killed organisms. Furthermore, tight junction ZO-1 protein was not lost intensity after inoculation with T. phagedenis and the organism was observed in NHEK cells using a florescence microscope. These results suggest that T. phagedenis strains may translocate via a transcellular route in vitro and that the invasion is accelerated by other bacteria, such as T. denticola, producing proteolytic activity.     

Characterization of Cu-resistant bacterial communities in Cu-contaminated soils

Bacterial communities in a spoil heap in a copper mine, a forest soil with high Cu contamination, and an agricultural soil with low Cu contamination were characterized in terms of Gram-staining, plasmid frequency, pigmentation, Cu-resistance system, and predominant Cu-resistant bacterial species. Similarity existed in that the ratio of green colonies for sorbing Cu and Gram-negative bacteria increased with the increase of the Cu content of the medium regardless of the characteristics of the bacterial communities. It was found that the plasmid was not present in most of the Cu-resistant bacteria of the soils. Curesistant genera including Burkholderia, Alcaligenes, and Methylobacterium species were isolated from the Cu contaminated soils using YG agar plates treated with 2 mM Cu. Furthermore, the bacterium with the highest Cu resistance (MIC = 5.5 mm Cu) was identified as a Gram-positive bacterium Bacillus sp., though most of the Cu-resistant bacteria were Gram-negative.