Dissertation > Excellent graduate degree dissertation topics show

Role of IL-6 in the Pathogenesis of an Avian Model of Staphylococcus Aureus Arthritis

Author: ZhouQuan
Tutor: ChengGuoFu
School: Huazhong Agricultural University
Course: Basic Veterinary Science
Keywords: chIL-6 Levofloxacin broiler Staphylococcus aureus Arthritis
CLC: S858.31
Type: Master's thesis
Year: 2005
Downloads: 82
Quote: 1
Read: Download Dissertation

Abstract

A suitable animal model has been developed to investigate a possible correlation for evaluating the role of interleukin-6 (IL-6) in Staphylococcus aureus-induced arthritis in chickens. Usingl20 8-week healthy boilers divided at random into four groups, two groups were injected with 0.35 mL of an 5. aureus suspension in physiological saline intra-articularly into the right hock joints and the other two in the same way with 0.35 mL of sterile physiological saline. One group in each of the two treatment groups was drenched with levofloxacin (LVFX) at dose of 5mg/kg body weight (BW) at 3rd d post inoculation (PI) for 4 successive days. Blood samples were obtained at selected intervals. ChJL-6 activities and concentrations in serum were quantified by B9 bioassay and enzyme-linked immunosorbent assay (ELISA), respectively.A rapid, sensitive and simple method, using the IL-6 dependent cell line B9, and MTT colorimetric assay, for determination of chIL-6 activity is established. A good linear relationship was found between the optical density value and the number of cells in each well when l.OxlO4 cells per well was incubated for 68 h before adding MTT. Optimal concentration and dosage of MTT was found to be 5 mg/ml dissolved by PBS and 20μL in each well.The best incubation period with MTT is 4 h. And the detectable limit of this mothod is 0.1 units (or 0.1 pg) of IL-6 in one milliliter.The infected birds appeared depressed, huddled and fever. After 7 PID, the arthrocele of the right hock became apparent, Two weeks or so, the left hock appeared arthrocele too. At the end of experiment, seven birds only injected with S. aureus died. The signs above all of infected birds treated with LVFX became slight gradually, and only a bird died in the experiment. At postmortem, lesions of infected birds consisted of swollen joints containing serous to caseous exudates. Hock cartilage appeared "insect corrosion" damage at 35th d PI. Tenden, articular cartilage and ligament were necrotic, cardiac muscles hemorrhagic and Liver hemorrhagic and necrotic. As for the infected birds treated with LVFX, there were no obvious lesions except hemorrhage in cardiac muscles and the liver. All controls remained clinically normal throughout the test.The histopathology examination of immune organs showed: at 35th d PI, the immune organs of infected birds basically returned to normal condition. Lymph nodules presented a change of lymphocytosis. But, there still existed somewhat injuries characterized by hemorrhage in thymus, caecal tonsil, and edema, hemorrhage, cystides formation in lymph follicle of bursa of fabricius. As for the infected birds treated with LVFX, there were ectoblast edema and cystides formation in lymph follicle of bursa of fabricius and more obvious changes with lymphocytosis.Serum IL-6 activity in the S. aureus-injected group began to grow 1st d PI and reached the maximal value on day 14. Comparable with the saline-treated group, serum IL-6 activity in the S. aureus-injected group was significantly higher (p of < 0.05 at 1, 4, 28 days; p of < 0.01 at 7, 14, 21 days). In the S. aureus plus LVFX treated group, chIL-6activities were significantly reduced (p of < 0.05 at 4, 7 days; p of < 0.01 at 14, 21 days) compared with birds injected only with S. aureus. But, there was no significant difference in serum chIL-6 levels between the broilers injected with sterile physiological saline and those uninfected treated with LVFX.Serum IL-6 concentration in the 5. awreus-injected birds remained elevated throughout the experiment and peaked 14 d PI, whereas in saline-treated birds retained the same. There was a significant difference about serum IL-6 concentration in infected birds, as compared with saline-treated group (p of < 0.05 at 1, 35 days; p of < 0.01 at 4, 7,14, 21, 28 days). In the S. aureus plus LVFX treated group, chIL-6 concentration was significantly reduced (p of < 0.05 at 7, 28, 35 days; p of < 0.01 at 4, 14, 21days) compared with birds injected only with S. aureus. But, there was no significant difference in serum chIL-6 levels between the two groups such as saline injected only and saline plus LVFX.Moreover, a good correlation was found between the ELISA and the B9 biological assay when chIL-6 in serum was measured.In conclusion, our results indicate chIL-6 participates in the infectious process of staphylococcus aureus arthritis in broilers and plays a detrimental role in the pathogenesis of S. aureus arthritis.

Related Dissertations

CLC: > Agricultural Sciences > Livestock, animal medicine,hunting,silkworm,bee > Animal Medicine ( Veterinary Medicine) > Livestock, poultry, wildlife diseases > Poultry > Chicken
© 2012 www.DissertationTopic.Net Mobile