Antimicrobial susceptibility and molecular characterization of avian pathogenic Escherichia coli isolates

Ninety-five avian pathogenic Escherichia coli (APEC) isolates recovered from diagnosed cases of avian colibacillosis from North Georgia between 1996 and 2000 were serotyped and examined for typical virulence-factors, susceptibility to antimicrobials of human and veterinary significance, and genetic relatedness. Twenty different serotypes were identified, with O78 being the most common (12%). The majority of the avian E. coli isolates (60%), however, were non-typeable with standard O antisera. Eighty-four percent of isolates were PCR positive for the temperature-sensitive hemagglutinin (tsh) gene and 86% positive for the increased serum survival (iss) gene. Multiple antimicrobial-resistant phenotypes (> or =3 antimicrobials) were observed in 92% of E. coli isolates, with the majority of isolates displaying resistance to sulfamethoxazole (93%), tetracycline (87%), streptomycin (86%), gentamicin (69%), and nalidixic acid (59%). Fifty-six E. coli isolates displaying resistance to nalidixic acid were co-resistant to difloxacin (57%), enrofloxacin (16%), gatifloxacin (2%), and levofloxacin (2%). DNA sequencing revealed point mutations in gyrA (Ser83-Leu, Asp87-Tyr, Asp87-Gly, Asp87-Ala), gyrB (Glu466-Asp, Asp426-Thr), and parC (Ser80-Ile, Ser80-Arg). No mutations were observed in parE. Twelve of the quinolone-resistant E. coli isolates were tolerant to cyclohexane, a marker for upregulation of the acrAB multi-drug resistance efflux pump. Quinolone-resistant isolates were further genetically characterized via ribotyping. Twenty-two distinct ribogroups were identified, with 61% of isolates clustering into four major ribogroups, indicating that quinolone resistance has emerged among multiple avian pathogenic E. coli serogroups and chromosomal backgrounds.     

The reproductive performance of farmed fallow deer (Dama dama) in New South Wales

Observations on the reproductive performance of fallow deer on 47 farms in New South Wales were made over 6 consecutive years. The minimum fawning rate for does varied significantly (p less than 0.001) between years, the corresponding fawning percentages varying from 75.0% to 96.4%, with an overall mean of 88.8%. The weaning rate also varied significantly (p less than 0.001) between years, the corresponding percentages varying from 65.0% to 89.1% with a mean over 6 years of 81.4%. Weaning rates were low given the known high fertility of fallow deer. The ratio of male to female fawns at weaning varied significantly (p less than 0.05) between years, although the ratio was exactly 1:1 for all births recorded over the 6-year period. The mean birthweights for female and male fawns were 4.01 kg +/- 0.61 (n = 330) and 4.23 kg +/- 0.72 (n = 348) respectively. Mean birthweights varied significantly (p less than 0.001) between the sexes and between years. There was a greater difference between birthweights of male and female fawns in years with higher mean fawn birthweight. Fawn birthweights generally approximated 10% of the pre-rut weight of their mother. Handling of newborn fawns for tagging and weighting did not increase the chance of mismothering and rejection. The mean weaning weight for doe fawns and buck fawns over 6 years was 18.7 kg (n = 227) and 21.2 kg (n = 231) respectively, with a mean birth to weaning interval of 108.4 +/- 4.89 (n = 458). Growth rates of male fawns from birth to weaning were significantly higher (p less than 0.01) than for female fawns, and the growth rates of fawns were significantly different (p less than 0.01) between years.(ABSTRACT TRUNCATED AT 250 WORDS)     

External balance of water and electrolytes in the horse

The components of the daily external water and electrolyte balances of five normal Standardbred geldings with a mean body weight of 427 kg, were determined over 14 day periods. The mean value of daily total water intake (a summation of free, combined and metabolic water intake) for the group was 27.6 litres, that is, 64.4 ml/kg body weight, while mean values for ambient temperature and humidity ranged from 16 to 25 degrees C and 55.4 to 75.5 per cent, respectively. The mean daily urine volume of 9.9 litres (23.2 ml/kg) for the group, was found to exceed the mean faecal water output of 7.2 litres (16.9 ml/kg). The mean output of sodium for the five animals, in urine and faeces, was 780 mmol or 79 per cent of the intake. The mean output of potassium, chloride, calcium and magnesium were 3163, 2521, 1824 and 1448 mmol or 95, 84, 74 and 75 per cent, respectively of intake. The sodium and potassium not accounted for in urine and faeces may well have been lost in sweat. Results are discussed and compared with those of a previous external balance study in the horse.     

Eumycotic mycetoma caused by Pseudallescheria boydii in the abdominal cavity of a dog

An abdominal eumycotic mycetoma with multiorgan dissemination was diagnosed in a 2-year-old dog. Clinical signs included fever, vomiting, diarrhea, weight loss, and a palpable abdominal mass. The dog developed disseminated intravascular coagulation and died. Pseudallescheria boydii was isolated from the abdominal mass, liver, and peritoneal fluid. Relevant history included an ovariohysterectomy when the dog was 6 months old, which was complicated by dehiscence of the incision site and evisceration. It appears that P boydii has a propensity for establishing itself in the abdominal cavity of the dog, subsequent to surgical dehiscence.     

A single genetic unit specifies two transposition functions in the maize element activator

The self-mobile maize transposable element Ac (Activator) displays two trans-acting genetic functions: it induces transposition of the element Ds (Dissociation) but, as its dosage is increased, it also inhibits transposition. Previous work has shown that the 4563 base pair (bp)-long Ac element contains three open reading frames (ORF's) and that a deletion in ORF 1 in wx-m9(Ds), a Ds derivative from Ac isolated at the wx (waxy) locus, results in loss of transposition. The Ds element in the bronze allele bz-m2(DI) is shown to have arisen from Ac by a 1312-bp deletion that is located almost entirely within ORF 2 and does not affect ORF 1. The Ds elements in wx-m9(Ds) and bzm2(DI), defective in ORF 1 and ORF 2, respectively, do not complement genetically to restore the transposition function of Ac; therefore, this function must be specified jointly by ORF's 1 and 2. Furthermore, since bz-m2(DI) does not contribute to Ac's inhibitory dosage effect, both Ac properties result from the expression of the same genetic functional unit.     

Role of hydrocolloids in the creaming of oil in water emulsions

The influence of guar gum and xanthan gum on the creaming of 10% oil in water emulsions has been investigated. The presence of very low concentrations of the polysaccharides (typically < approximately 0.075%) was found to induce depletion flocculation of the emulsion droplets and increased the rate of creaming. However, at higher polysaccharide concentrations (typically > approximately 0.1%) the creaming rate was reduced due to the increased viscosity of the aqueous phase. For most systems a delay period was noted before creaming started, which was found to be dependent on the zero shear viscosity of the continuous phase and independent of polysaccharide type. The delay period increased significantly at zero shear viscosities approaching 1 Pa s. A mathematical model has been used to fit the creaming rate profiles and a simple exponential relationship obtained between delay time and polysaccharide concentration.     

Folate Content and Chemical Composition of Commercially Available Gluten-Free Flour Alternatives

Plant Foods for Human Nutrition - Concerns about the nutritional and sensory qualities of gluten-free (GF) products has generated interest in the evaluation of novel gluten-free ingredients. Folate...     

Estimating the demand and willingness-to-pay for cotton yield monitors

Survey data from cotton farmers in six southeastern states of the USA were used to estimate the demand and willingness-to-pay (WTP) for either retrofitting yield monitors onto cotton pickers or to purchase a yield monitor as an option with a new cotton picker. ‘Don’t know’ responses were either omitted, combined with ‘no’ responses or included as a separate category for comparing WTP and estimates of the price elasticity of demand. Our results suggest that treating the ‘don’t know’ response as a separate category provides WTP estimates that are more consistent with expectations than the other approaches. The estimated price elasticities and demand curves indicate that previous users of precision technology are more responsive to changes in price of cotton yield monitors and would be more likely to adopt them when the price decreases. These demand and WTP estimates provide important information that can be used by those who sell cotton yield monitors, as well as policy-makers who may wish to subsidize this technology. Referendum contingent valuation was useful for evaluating the demand for any new technology.     

Grid soil sampling adoption and abandonment in cotton production

Technology adoption in precision agriculture has received considerable attention, while abandonment has received little. Survey data are now available to evaluate adoption and abandonment decisions. Understanding the factors motivating technology adoption and abandonment has implications for educational efforts directed toward improving the efficiency of production inputs and for research and development to improve the value of precision agriculture technologies. The objective of this research was to identify factors motivating the adoption and abandonment of grid soil sampling in precision cotton production. These decisions were evaluated assuming a random utility model. Data were obtained from a 2005 survey of cotton producers in 11 Southeastern states in the USA. Results from limited dependent variable regressions indicate that younger producers who farmed more cotton area, owned more of their cropland, planted larger amounts of non-cotton area, used a computer for farm management and used a Personal Digital Assistant (PDA) in the field were more likely to adopt grid soil sampling for cotton precision farming. Results also suggest that producers with more cotton area who owned livestock and adopted management zone soil sampling were more likely to abandon grid soil sampling, while those who used a PDA in the field, used grid soil sampling for more years and followed up grid soil sampling with variable-rate fertilizer application were less likely to abandon grid soil sampling for cotton production.