呕吐毒素对感染鸡毒支原体和禽致病性大肠杆菌雏鸡的影响

Effects of deoxynivalenol on chickens infected with Mycoplasma gallitatis and avain pathogenic Escherichia coli

鸡毒支原体是导致禽多病因气囊炎的重要病原之一,经常与禽致病性大肠杆菌混合感染,严重威胁养禽业的健康发展。此外,饲料中的霉菌毒素是一大类由真菌、霉菌的产生的二级代谢产物,给人类和动物健康带来严重的风险。为了探究霉菌毒素与鸡毒支原体及禽致病性大肠杆菌混合感染的相关性,以浓度为1×10^(10)CCU/mL鸡毒支原体S6标准菌株接种7日龄麻黄鸡,6天后接种1×10^(7)CFU/mL禽致病性大肠埃希氏杆菌O78株,并在试验期间饲喂含8 mg/kg呕吐毒素饲料。试验结果表明,雏鸡感染鸡毒支原体和禽致病性大肠杆菌后,不会导致呼吸道感染的相关临床症状出现;在感染上述病原的基础上,饲喂呕吐毒素会导致鸡毒支原体的抗体水平显著下降,血液中鸡毒支原体的检出率明显升高。该研究评价了呕吐毒素的免疫抑制能力,且证实雏鸡多病因气囊炎的发生可能需其他致病因子。

Mycoplasma gallitatis(MG)which often co⁃infect with Avian pathogenic Escherichia coli.(APEC)is an important pathogen for avian air saccultitis and put poultry industry in serious risks.In the meantime,mycotoxins as secondary metabolites produced by fungi or molds bring serious challenges to poultry health.In order to understand the correlation between mycotoxin and MG infection,7⁃day⁃old chickens were inoculated with MG S6 strain at 1×10^(10) CCU/mL for 3 days.Chickens were inoculated with avain pathogenic Escherichia coli(APEC)O78 strain at 1×10^(7) CFU/mL 6 days later to induce the symptoms of diseases.During the experiment,8 mg/kg deoxynivalenol(DON)was fed through daily diet.The results showed that,at the condition of DON exposure,chickens did not show clinical symptoms of respiratory disease by MG and APEC infection,but the exposure of DON could significantly reduce the antibody level of MG and increase the detection rate of the MG in chicken blood.This study evaluated the immunosuppressive ability of DON and confirmed that other pathogenic factors may be needed for the occurrence of multi etiological air saccultitis in chicks.