40,035 research outputs found
Antimicrobial susceptibility assessment of Campylobacter on outdoor iberian pig sows
Both Campylobacter and Salmonella are considered the most frequent bacterial causes of human enteritis in
industrialized countries. The consumption of raw or undercooked poultry and pork contaminated meat products
are the main sources of human infection. The prevalence of Campylobacter and Salmonella was determined in
the present work for extensive production Iberian pig sows, Sus mediterraneus. Samples were collected at the
maternity area of a creator from, water drinkers, feed and feed containers as well as from sows faecal matter. Of
42 samples, 31 and 23 carried Campylobacter spp. and Salmonella spp. respectively. Only Salmonella spp. was
found in all 3 tested water and feed containers. Of the 58 isolated Campylobacter strains only one was identified,
by multiplex-PCR, as Campylobacter jejuni, all other were C. coli. Antibiotic susceptibility was performed by
disc diffusion method with Nalidixic acid, Ciprofloxacin, Erythromycin, Tetracycline, Chloramphenicol and
Ampicilin. While 95% of the tested strains were susceptible to chloramphenicol, 66% and 53% were resistant to
the tested fluoroquinolones, Ciprofloxacin and Nalidixic acid respectively. Erythromycin resistance was fairly
low in comparison to previous publications with 14% of resistant strains. 38% were resistant to Tetracycline and
57% to Ampicilin. Seven of the 58 Campylobacter strains were entirely susceptible and none were resistant to all
the antimicrobials tested. Multiple drug resistance was found in 88% of strains. Cross contamination may occur
between sows inside maternity facilities and piglets may become infected in an early age by their mothers. New
and better control measures are therefore necessary to minimize transmission between animals reducing the
number of contaminated individuals and the potential transmission to human handlers and consumers
Transfer of optical spectral weight in magnetically ordered superconductors
We show that, in antiferromagnetic superconductors, the optical spectral
weight transferred to low frequencies below the superconducting transition
temperature originates from energies that can be much larger than twice the
superconducting gap . This contrasts to non-magnetic superconductors,
where the optical spectrum is suppressed only for frequencies below .
In particular, we demonstrate that the superfluid condensate of the
magnetically ordered superconductor is not only due to states of the
magnetically reconstructed Fermi surface, but is enhanced by transfer of
spectral weight from the mid infrared peak generated by the spin density wave
gap. We apply our results to the iron arsenide superconductors, addressing the
decrease of the zero-temperature superfluid density in the doping regime where
magnetism coexists with unconventional superconductivity.Comment: 5 figures, 10 pages; revised versio
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