Isolation of Listeria monocytogenes from the skin of slaughtered beef cattle

We attempted to isolate Listeria monocytogenes from skin, contents of large intestines and carcasses of cattle introduced to a slaughterhouse in order to identify source of contamination for this pathogen. Sixty skin samples, 60 samples of the contents of large intestines and 30 carcass samples were colleted in June, August and November 2003 for use in this study. Listeria spp. and L. monocytogenes were isolated from 30 (50%) and 3 (5%) of the cattle skin samples, respectively. However, no Listeria spp., including L. monocytogenes, were isolated from intestinal contents or carcasses. Seven isolates were obtained, of which five and two strains were serotypes 1/2a and 1/2b, respectively. Genetic analysis suggested that there was persistent inhabitation of the pathogen around the area investigated in this study.     

Production and analysis of reciprocal hybrids between <Emphasis Type="Italic">Asparagus officinalis</Emphasis> L. and <Emphasis Type="Italic">A. schoberioides</Emphasis> Kunth

The genus Asparagus (Asparagaceae) encompasses 100–300 species, including the important vegetable crop, A. officinalis (garden asparagus). Previous attempts to hybridize garden asparagus with A. densiflorus (Kunth) Jessop, with the aim of introducing disease resistance, were unsuccessful because of the failure of endosperm development. In the present study, reciprocal interspecific hybrids between garden asparagus and A. schoberioides Kunth were generated by hand pollination. The F1 hybrids were analyzed by using both morphological and molecular techniques. This is the first report describing the production of an interspecific hybrid between garden asparagus at the diploid level (2n = 2x = 20) and its diploid (2n = 2x = 20) wild relative, A. schoberioides. Morphological characteristics of candidate hybrids were a mixture of those found in the parents, and cytological and RFLP analyses confirmed that morphologically intermediate plants were indeed diploid hybrids of those two species. In other words, post-zygotic isolation is not complete between phylogenetically distinct these two species. Our results suggest that other Asparagus species may be capable of hybridizing with A. officinalis and that introducing wild characters through interspecific hybridization may offer advantages for breeding for novel traits. Takuro Ito and Toshinori Ochiai authors are contributed equally to this work     

Interaction of coenzyme Q10 with the intestinal drug transporter P-glycoprotein

In clinical trials, patients usually take many kinds of drugs at the same time. Thus, drug-drug interactions can often directly affect the therapeutic safety and efficacy of many drugs. Oral delivery is the most desirable means of drug administration. Changes in the activity of drug transporters may substantially influence the absorption of administered drugs from the intestine. However, there have been a few studies on food-drug interactions involving transporters. It is important to be aware of the potential of food-drug interactions and to act in order to prevent undesirable and harmful clinical consequences. Coenzyme Q10 (CoQ10) is very widely consumed by humans as a food supplement because of its recognition by the public as an important nutrient in supporting human health. Since intestinal efflux transporter P-glycoprotein (P-gp) is one of the major factors in drug-drug interactions, we focused on this transporter. We report here for the first time that CoQ10, which is widely used as a food supplement, affects the transport activity of P-gp.     

Green manure effects on soil quality in relation to suppression of Verticillium wilt of potatoes

Verticillium dahliae is a major, persistent pathogen in soil but conventional control is becoming more difficult because of increasing costs and environmental impacts of pesticides. Organic amendments can naturally suppress plant diseases, but to be reliable, mechanisms and suppressive soil indicators need to be understood. Consequently, a 3 × 3 factorial experiment was conducted in two separate fields over 2 years with three green manure types (Austrian winter pea, Pisum sativum L.; broccoli Brassica oleracea L.; or Sudan grass, Sorghum vulgare), incorporated at three rates (6, 12, or 24 Mg ha⁻¹ dry biomass). The relationship between soil chemical and microbiological properties and suppression of Verticillium wilt of potato was investigated using correlation and stepwise multiple-linear-regression (MLR) analysis. V. dahliae inoculum density (ID) were positively correlated with relative area under the senescence progress curve (RAUSPC) in both 2002 and 2003. In 2002, in addition to ID, low soil pH, low Ca, high K, high Mg, high total soil C, and low arylsulfatase activity were associated with low RAUSPC. Soil pH, Ca, K, and Mg were not impacted by green manure treatments, but rather indicated a pre-existing soil gradient at the 2002 site. In 2003, in addition to ID, high values of NO₃ ⁻−N, total C, fluorescein diacetate hydrolysis (FDA), microbial respiration, and microbial biomass C were associated with low RAUSPC. These six factors were affected by green manure treatments. The best MLR model included terms for ID, FDA, and soil pH, and accounted for 70% of the variability in RAUSPC.     

pH- and temperature-dependent denaturation profiles of tuna myoglobin

Attempts have been made to elucidate the denaturation profiles of tuna myoglobin (Mb) in comparison with horse Mb. Intensive absorbance characterization was carried out for derivatives (deoxy, oxy, met forms) of Mb. The wavelength of the maximum absorbance of tuna Mb was shorter only by 1 nm for deoxy and metMb, while it was 4 nm shorter for the second peak of metMb. Percentage Mb denaturation (PMD) was measured under a combination of pH (5.6, 6.5, 7.4) and temperature (70, 75, 80 °C). Tuna Mb was almost completely denatured even during the initial incubation at 75 and 80 °C at all pHs examined. During the incubation at 70 °C, the PMD values for tuna Mb were 88.5, 52.1, and 67.7% at pH 5.6, 6.5, and 7.4, respectively. The denaturation of tuna Mb proceeded even at 55 °C, but denaturation rates were very slow at pH 6.5. On the other hand, horse Mb was found to be very stable at pH 6.5 and 7.4 at all temperatures examined, except at pH 6.5 and 80 °C. At pH 5.6, the PMD values of horse Mb gradually increased, especially at 75 and 80 °C. These different Mbs showed quite different denaturation profiles.