Campylobacter spp., Salmonella spp., Verocytotoxic Escherichia coli, and Antibiotic Resistance in Indicator Organisms in Wild Cervids

Faecal samples were collected, as part of the National Health Surveillance Program for Cervids (HOP) in Norway, from wild red deer, roe deer, moose and reindeer during ordinary hunting seasons from 2001 to 2003. Samples from a total of 618 animals were examined for verocytotoxic E. coli (VTEC); 611 animals for Salmonella and 324 animals for Campylobacter. A total of 50 samples were cultivated from each cervid species in order to isolate the indicator bacterial species E. coli and Enterococcus faecalis/E. faecium for antibiotic resistance pattern studies. Salmonella and the potentially human pathogenic verocytotoxic E. coli were not isolated, while Campylobacter jejuni jejuni was found in one roe deer sample only. Antibiotic resistance was found in 13 (7.3%) of the 179 E. coli isolates tested, eight of these being resistant against one type of antibiotic only. The proportion of resistant E. coli isolates was higher in wild reindeer (24%) than in the other cervids (2.2%). E. faecalis or E. faecium were isolated from 19 of the samples, none of these being reindeer. All the strains isolated were resistant against one (84%) or more (16%) antibiotics. A total of 14 E. faecalis-strains were resistant to virginiamycin only. The results indicate that the cervid species studied do not constitute an important infectious reservoir for either the human pathogens or the antibiotic resistant microorganisms included in the study

Improvement of acetaldehyde production in Zymomonas mobilis by engineering of Its aerobic metabolism

Acetaldehyde is a valuable product of microbial biosynthesis, which can be used by the chemical industry as the entry point for production of various commodity chemicals. In ethanologenic microorganisms, like yeast or the bacterium Zymomonas mobilis, this compound is the immediate metabolic precursor of ethanol. In aerobic cultures of Z. mobilis, it accumulates as a volatile, inhibitory byproduct, due to the withdrawal of reducing equivalents from the alcohol dehydrogenase reaction by respiration. The active respiratory chain of Z. mobilis with its low energy-coupling efficiency is well-suited for regeneration of NAD+ under conditions when acetaldehyde, but not ethanol, is the desired catabolic product. In the present work, we sought to improve the capacity Z. mobilis to synthesize acetaldehyde, based on predictions of a stoichiometric model of its central metabolism developed herein. According to the model analysis, the main objectives in the course of engineering acetaldehyde producer strains were determined to be: (i) reducing ethanol synthesis via reducing the activity of alcohol dehydrogenase (ADH), and (ii) enhancing the respiratory capacity, either by overexpression of the respiratory NADH dehydrogenase (NDH), or by mutation of other components of respiratory metabolism. Several mutants with elevated respiration rate, decreased alcohol dehydrogenase activity, or a combination of both, were obtained. They were extensively characterized by determining their growth rates, product yields, oxygen consumption rates, ADH, and NDH activities, transcription levels of key catabolic genes, as well as concentrations of central metabolites under aerobic culture conditions. Two mutant strains were selected, with acetaldehyde yield close to 70% of the theoretical maximum value, almost twice the previously published yield for Z. mobilis. These strains can serve as a basis for further development of industrial acetaldehyde producers

Stereotactic body radiotherapy for organ-confined prostate cancer

<p>Abstract</p> <p>Background</p> <p>Improved understanding of prostate cancer radiobiology combined with advances in delivery of radiation to the moving prostate offer the potential to reduce treatment-related morbidity and maintain quality of life (QOL) following prostate cancer treatment. We present preliminary results following stereotactic body radiotherapy (SBRT) treatment for organ-confined prostate cancer.</p> <p>Methods</p> <p>SBRT was performed on 304 patients with clinically localized prostate cancer: 50 received 5 fractions of 7 Gy (total dose 35 Gy) and 254 received 5 fractions of 7.25 Gy (total dose 36.25 Gy). Acute and late toxicity was assessed using the Radiation Therapy Oncology Group scale. The Expanded Prostate Cancer Index Composite questionnaire was used to assess QOL. Prostate-specific antigen response was monitored.</p> <p>Results</p> <p>At a median 30-month (26 - 37 month, range) follow-up there were no biochemical failures for the 35-Gy dose level. Acute Grade II urinary and rectal toxicities occurred in 4% of patients with no higher Grade acute toxicities. One Grade II late urinary toxicity occurred with no other Grade II or higher late toxicities. At a median 17-month (8 - 27 month, range) follow-up the 36.25 Gy dose level had 2 low- and 2 high-risk patients fail biochemically (biopsy showed 2 low- and 1 high-risk patients were disease-free in the gland). Acute Grade II urinary and rectal toxicities occurred in 4.7% (12/253) and 3.6% (9/253) of patients, respectively. For those patients with a minimum of 12 months follow-up, 5.8% (12/206) had late Grade II urinary toxicity and 2.9% (6/206) had late Grade II rectal toxicities. One late Grade III urinary toxicity occurred; no Grade IV toxicities occurred. For both dose levels at 17 months, bowel and urinary QOL returned to baseline values; sexual QOL decreased by 10%.</p> <p>Conclusions</p> <p>The low toxicity and maintained QOL are highly encouraging. Additional follow-up is needed to determine long-term biochemical control and maintenance of low toxicity and QOL.</p

Metabolic and evolutionary insights into the closely-related species Streptomyces coelicolor and Streptomyces lividans deduced from high-resolution comparative genomic hybridization

Whilst being closely related to the model actinomycete Streptomyces coelicolor A3(2), S. lividans 66 differs from it in several significant and phenotypically observable ways, including antibiotic production. Previous comparative gene hybridization studies investigating such differences have used low-density (one probe per gene) PCR-based spotted arrays. Here we use new experimentally optimised 104,000 × 60-mer probe arrays to characterize in detail the genomic differences between wild-type S. lividans 66, a derivative industrial strain, TK24, and S. coelicolor M145