畜禽舍空气细菌内毒素两种检测方法的比较研究

Comparison of Two Detection Methods for Airborne Bacterial Endotoxin in Livestock and Poultry Houses

[目的 ]比较气相色谱-串联质谱法(GC-MSMS)与鲎试验(LAL)在检测畜禽舍空气内毒素中的应用效果及相关性,以及气载内毒素是否对环境和饲养人员健康构成危害。[方法 ]通过国际标准AGI-30液体冲击式空气采样器,在4个养殖场16个畜禽舍采集空气样品,采用GC-MSMS与LAL测定空气细菌内毒素浓度。[结果 ]LAL测定的牛舍、猪舍、羊舍和禽舍空气细菌内毒素浓度中间值分别为1.85×10~5 EU/m^3、2.76×10~6 EU/m^3、4.82×10~5 EU/m^3、6.55×10~6 EU/m^3;而GC-MSMS测定的分别为3.3×10~4 EU/m^3、1.26×10~5 EU/m^3、2.4×10~4EU/m^3和8.21×10~5 EU/m^3。GC-MSMS在禽舍检测出的空气内毒素浓度显著大于其他畜舍(p<0.05)。用LAL和GC-MSMS分析测定的空气中内毒素浓度超过了对大多数动物和人体有威胁的阈限值1.0×10~3EU/m^3。用GCMSMS与LAL测定的禽舍和羊舍空气样品中细菌内毒素浓度之间存在显著相关(p<0.05),而牛舍和猪舍之间浓度没有显著相关性。GC-MSMS主要检测存在于动物舍空气内毒素中含有C_(14)-C_(18)链的3-羟基脂肪酸。LAL测定的内毒素浓度与含有C_(14)-C_(16)链3-羟基脂肪酸量之间有显著相关(p<0.05)。[结论 ]GC-MSMS与LAL联合应用可以提高检测气载内毒素的准确性,且本研究表明畜禽舍中检测到的空气细菌内毒素浓度可以危害人类和家畜动物健康。

[Objective] To compare the application effect and correlation of the gas chromatography–tandem mass spectrometry method（GC-MSMS）and the Limulus test（LAL）in testing the airborne endotoxin,and to analyze whether airborne endotoxin is harmful to the environment and breeders health. [Methods] Air samples were collected by using the international standard AGI-30 air samplers of liquid impingement in 16 livestock and poultry houses from 4 farms,and examined for the concentration of bacterial endotoxin with the LAL test and GC-MSMS technique. [Results] The median concentrations of airborne endotoxin determined by LAL test in cow barns,piggeries,sheep sheds and poultry houses were 1.85×10^5 EU/m^3,2.76×10^6 EU/m^3,4.82×10^5 EU/m^3,6.55×10^6 EU/m^3 respectively,while those measured by the GC-MSMS technique were respectively 3.3×10^4 EU/m^3,1.26×10^5 EU/m^3,2.4×10^4 EU/m^3 and 8.21×10^5 EU/m^3. The concentrations of airborne endotoxin detected by GC-MSMS method in poultry houses were significantly higher than any other examined barns（p〈0.05）. The concentrations of airborne endotoxin determined with LAL test and GC-MSMS analysis surpassed the threshold（1.0×10^3EU/m^3）above which would be harmful to most animals and humans. A significant correlation（p〈0.05）between the concentrations of endotoxin determined by the LAL and GC-MSMS techniques was found in the air samples from poultry houses and sheep sheds,but not found in other examined barns. GC-MSMS method was designed to detected 3-hydroxy fatty acids containing C14–C18 chains of airborne bacterial endotoxin in livestock and poultry houses. A significant correlation（p〈0.05）was found between the concentrations of endotoxin determined with LAL test and the amounts of 3-hydroxy fatty acids with C14–C16 chains. [Conclusion] The combination of GC-MSMS technique and LAL test will improve the accuracy of measurement. The endotoxin concentration detected in this study could be a respiratory hazard to both humans and livestock animals.