Search

Supplementing chicken feed with antibiotics can improve survival and prevent disease outbreaks. However, overuse of antibiotics may promote the development of antibiotic-resistant bacteria. Recently, antimicrobial peptides have been proposed as alternatives to antibiotics in animal husbandry. Here, we evaluate the effects of antimicrobial peptide, Epinephelus lanceolatus piscidin (EP), in Gallus gallus domesticus. The gene encoding EP was isolated, sequenced, codon-optimized and cloned into a Pichia pastoris recombinant protein expression system. The expressed recombinant EP (rEP) was then used as a dietary supplement for G. g. domesticus; overall health, growth performance and immunity were assessed. Supernatant from rEP-expressing yeast showed in vitro antimicrobial activity against Gram-positive and Gram-negative bacteria, according to an inhibition-zone diameter (mm) assay. Moreover, the antimicrobial peptide function of rEP was temperature independent. The fermentation broth yielded a spray-dried powder formulation containing 262.9 μg EP/g powder, and LC-MS/MS (tandem MS) analysis confirmed that rEP had a molecular weight of 4279 Da, as expected for the 34-amino acid peptide; the DNA sequence of the expression vector was also validated. We then evaluated rEP as a feed additive for G. g. domesticus. Treatment groups included control, basal diet and rEP at different doses (0.75, 1.5, 3.0, 6.0 and 12%). Compared to control, rEP supplementation increased G. g. domesticus weight gain, feed efficiency, IL-10 and IFN-γ production. Our results suggest that crude rEP could provide an alternative to traditional antibiotic feed additives for G. g. domesticus, serving to enhance growth and health of the animals.

Background/Purpose This study compares heart rate variability (HRV) and systolic blood pressure (SBP) changes of spinal cord injury (SCI) patients during urodynamic study (UDS) with able-bodied controls. Methods Twenty four complete suprasacral SCI patients (12 tetraplegia and 12 paraplegia) and 12 age-matched able-bodied volunteers received BP and HRV evaluation throughout urodynamic examination. We chose seven time points during the examinations: resting, Foley catheter insertion, start of infusion, and infused volume reaching 1/4, 2/4, 3/4 and 4/4 of maximal capacity. At each time point, electrocardiogram with a duration of 5 min was used for power spectral density analysis of HRV. Results Only control subjects displayed significant elevation of SBP during Foley catheter insertion compared to resting values. Both control and tetraplegic groups experienced significant elevation of SBP at maximal bladder capacity compared to resting values. Tetraplegic values were also significantly greater than the other two groups. Control subjects displayed significant elevation of low frequency/high frequency (LF/HF) ratios during Foley catheter insertion and when approaching maximum bladder capacity. These findings were not seen in the paraplegic and tetraplegic groups. However, subgroup analysis of tetraplegic subjects with SBP elevation >50 mmHg demonstrated a similar LF/HF response to the able-bodied controls. Conclusion Tetraplegic patients experienced BP elevation but did not experience significant changes in HRV during bladder distension. This finding may imply that different neurological pathways contribute to AD reaction and HRV changes during bladder distension. However, profound AD during UDS in tetraplegic patients was associated with corresponding changes in HRV. Whether HRV monitoring would be beneficial in SCI patients presenting with significant AD, it needs further studies to elucidate.