Relations between plasma IGF-I concentrations during treatment with CIDR-based or Ovsynch protocol for timed AI and conception in early postpartum Japanese black beef cows

We examined the relations between plasma insulin-like growth factor (IGF) -I concentrations during treatment with CIDR-based or Ovsynch protocol for timed AI and conception and plasma steroid concentrations in early postpartum Japanese Black beef cows. Cows in the control group (Ovsynch; n = 21) underwent Ovsynch protocol (GnRH analogue on Day 0, PGF(2alpha) analogue on Day 7, and GnRH analogue on Day 9), with AI on Day 10, approximately 20 h after the second GnRH treatment. Cows in the Ovsynch+CIDR group (n = 22) received Ovsynch protocol plus a CIDR for 7 days (starting on Day 0). Cows in the further treatment group (EB+CIDR+GnRH; n = 22) received 2 mg of estradiol benzoate (EB) on Day 0 in lieu of the first GnRH treatment, followed by the same treatment as in the Ovsynch+CIDR protocol. Plasma IGF-I concentrations were determined on Days -7, 0, 7, 9 and 17. Conception rates were improved in the CIDR-combined groups (both CIDR-treated groups were combined) relative to Ovsynch group (P < 0.05) for cows with low IGF-I concentrations (<1,000 ng/ml) on Days -7, 0, and 7, but improved conception rate produced by the CIDR-based protocols did not occur in cows with a high IGF-I concentration (> or =1,000 ng/ml). Plasma estradiol-17beta concentrations increased from Day 0 to 7 (P < 0.05) and were unchanged from Day 7 to 9 in the Ovsynch group with low IGF-I concentrations on Day 0, while they were unchanged from Day 0 to 7 and increased from Day 7 to 9 (P < 0.05) in the Ovsynch group with high IGF-I concentrations on Day 0 and in the CIDR-combined group. Plasma progesterone concentrations in the Ovsynch group with low IGF-I concentrations on Day 0 were higher on Day 14 than in the Ovsynch group with high IGF-I concentrations on Day 0 and in the CIDR-combined group (P < 0.05). In conclusion, CIDR-based protocols may improve conception relative to Ovsynch in early postpartum beef cows with lower plasma IGF-I concentrations at the start of the protocols. This improvement is probably due to prevention of premature increases of estradiol-17beta and progesterone concentrations, which occurred in cows with low IGF-I concentrations treated with Ovsynch, by the CIDR treatment.     

Inhibition of phosphorus sorption to goethite, gibbsite, and kaolin by fresh and decomposed organic matter

The direct effects of dissolved organic matter (DOM) on the sorption of orthophosphate onto gibbsite, goethite, and kaolin were examined using a one-point phosphorus sorption index and the linear Tempkin isotherm model. DOM extracted from fresh and decomposed agricultural residues, as well as model organic and humic acids, were used. Changes in the chemical and sorptive characteristics of the DOM in the absence and presence of added orthophosphate (50 mg l⁻¹) were also determined. For residue-derived materials, DOM sorption to all minerals correlated well with percent hydrophobicity, apparent molecular weight, and phenolic acidity in the absence of added orthophosphate. Sorption of DOM to goethite and gibbsite was significantly decreased in the presence of added P. The correlation coefficient values of percent hydrophobicity, apparent molecular weight, and phenolic acidity to sorption also declined in the presence of added P. Thus, the addition of P substantially lowered fractionation of DOM after sorption to goethite and gibbsite. In contrast, few significant P sorption-induced differences were observed in the kaolin system. According to one-point P sorption results, DOM in the form of Aldrich humic acid, oxalate, and decomposed clover and corn residue, significantly inhibited P sorption to goethite at concentrations of 50 and 200 mg total soluble carbon (C_TS l⁻¹). Phosphorus sorption to gibbsite was significantly inhibited by 50 mg C_TS l⁻¹ derived from decomposed corn residue, fresh dairy manure residue, and oxalate solution. At 200 mg C_TS l⁻¹, all DOM solutions were found to inhibit P sorption to gibbsite. This study suggests that DOM inhibition of P sorption depends on the chemical properties of both the sorbent and the DOM itself. In general, DOM from decomposed organic materials inhibited P sorption to a greater extent than did DOM derived from fresh materials. This stronger inhibition highlights the importance of microbial processes in the release of soluble soil P, a key determinant of P availability to plants.     

Oligotrophic bacteria on organic debris and plant roots in a paddy field soil

The distribution of heterotrophic bacteria on organic debris and roots of rice plants in a paddy field were studied. The heterotrophic bacteria consisted of two main groups: those which grew on full-strength nutrient broth (NB) and those which did not grow on NB but on a 100-fold dilution of NB (DNB). The latter group was called ‘DNB organisms’ and were considered to be oligotrophic. In both manured and unmanured soils, DNB organisms were predominant in the bacterial communities on organic debris and the rice roots throughout most of the entire period of rice cultivation, although a transient decrease in the proportion of DNB organisms was observed immediately after an application of manure. Morphological and physiological characteristics of DNB isolates from organic debris and rice roots were studied: five types of cell shape were observed, (1) regular rods, (2) filament-forming rods, (3) irregular rods, (4) prosthecate organisms and (5) large oval cells. Regular rods (42% of the total DNB isolates) and irregular rods (46%) were abundant. The ecological roles of DNB organisms in paddy soil are discussed in relation to their physiological characteristics.     

False positive responses of Campylobacter jejuni when using the chemical-in-plug chemotaxis assay

Campylobacter jejuni reportedly exhibits chemotactic behavior towards fucose, several amino acids and organic acids, mucin and bile. The chemotaxis of C. jejuni has mainly been studied using the chemical-in-plug chemotaxis assay. In this study, a nonchemotactic mutant (cheY mutant) and nonmotile mutant (flhA mutant) were constructed and used as negative controls in an assay. Apparent zones of accumulation around test plugs containing several amino acids and organic acids were observed with both of the mutants. Our results suggest that positive responses of C. jejuni in the chemical-in-plug assay are not always indicative of chemotaxis.     

Endocarditis in chickens caused by subclinical infection of Streptococcus gallolyticus subsp. gallolyticus

Streptococcus gallolyticus subsp. gallolyticus causes endocarditis in humans and acute septicemia in domestic birds. We describe here the infective endocarditis caused by the bacterium found among clinically healthy broilers at two abattoirs in Japan. The chickens were thought to be healthy because of the lack of clinical symptoms and normal levels of mortality before slaughtering. At the time of inspection, some chickens were condemned because of organ disorders characterized by vegetative valvular endocarditis as well as focal necrosis in heart, liver, and spleen. Streptococcus gallolyticus subsp. gallolyticus was isolated from the organs as a pure culture, indicating that the bacterium probably was the causative agent of the disorders. Amplified fragment length polymorphism analysis of the isolates collected at the abattoirs from chickens grown in nine different farms indicated that the isolates were different variants of the same clonal lineage and may have been derived from the same ancestor. These results suggest that S. gallolyticus subsp. gallolyticus causes infectious endocarditis in chickens and that healthy chickens may possess the bacterium in their normal flora as an opportunistic pathogen.     

A survey of amoebic infections and differentiation of an Entamoeba histolytica-like variant (JSK2004) in nonhuman primates by a multiplex polymerase chain reaction

A pathogenic Entamoeba histolytica-like variant (JSK2004 strain) with genetic variations and a novel isoenzyme pattern isolated from a De Brazza's guenon in a Tokyo zoo in Japan has previously been documented. In this study, a multiplex polymerase chain reaction (PCR) assay that could distinguish the JSK2004-type E. histolytica-like variant (JSK04-Eh-V) from E. histolytica and Entamoeba dispar using three newly designed primer sets for amplifying each specific DNA fragment from their small-subunit ribosomal RNA genes was developed and established. Forty-seven primates (11 species) from the zoo were surveyed by multiplex PCR to assess the prevalence of JSK04-Eh-V infection, which was recognized in six individuals of four species, including an Abyssinian colobus monkey, a De Brazza's guenon (including the individual from whom JSK2004 was isolated), a white-faced saki, and a Geoffroy's spider monkey. In addition, the autopsied individuals of an Abyssinian colobus and Geoffroy's spider monkey that died of amoebic liver abscess were also evaluated. DNA samples were also analyzed for specific genotypes based on the nucleotide sequencing of two protein-coding (chitinase and serine-rich E. histolytica protein) genes and the protein-noncoding locus 1-2 that was used for fingerprinting of the E. histolytica strain. These studies indicated that the E. histolytica-like variant infection in this zoo was caused by the same type (i.e., JSK04-Eh-V). An axenic culture medium (yeast extract-iron-maltose-dihydroxyacetone-serum) was developed based on the yeast extract-iron-gluconic acid-dihydroxyacetone-serum medium, which is designed for axenic culture of E. dispar. This new medium could be used for axenically culturing E. histolytica, JSK04-Eh-V, and E. dispar in a single medium.     

Fusariosis in rubber tree: pathogenic,morphological, and molecular characterization of the causal agent

Fusariosis, one of the phytosanitary problems found in rubber producing areas in the northwest of the state of São Paulo, is a disease that affects the bark of the adult plants, affecting the exploitation of latex. The typical symptoms appear as cracks in the bark that expand from the rootstock towards the tapping panel, causing a drying of the latex flux in the injured region, impeding latex tapping. Due to the recent incidence of this disease in rubber plantations, the goal of this study was to characterize the Fusarium associated with symptomatic rubber tissue in three different locations in the state of São Paulo. In order to identify Fusarium species, pathogenicity, morphological, cultural and molecular studies were carried out. A total of 51 isolates were obtained and separated into three groups based on macroconidium morphology, presence or absence of sporodochia, types of chlamydospores, formation of phialides and conidiogenesis of microconidia and mesoconidia, mycelial growth rate and coloring of the colonies. These groups were corroborated using DNA sequence information for five different genetic loci, and were subsequently recognized as Fusarium oxysporum, F. incarnatum and F. decemcellulare. Our results further showed that all 51 of the Fusarium isolates recovered were pathogenic to rubber tree seedlings of RRIM 600 standard clone. This study also reports for the presence of F. oxysporum and F. incarnatum in rubber plantations in the state of São Paulo and in Brazil.