Waage S, Jonsson P, Franklin A
National Veterinary Institute, Oslo, Norway.
Acta Vet Scand. 1994;35(2):207-12. doi: 10.1186/BF03548348.
A modified Limulus amebocyte lysate (LAL) cow-side test was evaluated under field conditions. The principle of the test is to visualize reactions between test components and endotoxin from the cell wall of Gram-negative bacteria. The practical purpose is to detect such bacteria in mastitic milk. Secretions from 789 udder quarters with clinical mastitis were examined by the LAL-test. Parallel quarter milk samples were sent to a mastitis laboratory of microbiological examination. Eleven veterinary surgeons in three veterinary districts in Norway performed the field investigations. Results of the LAL-test and culture agreed in 93% of all milk samples tested, agreement measured by kappa being 0.63. The sensitivity of the test in detecting Gram-negative bacteria was 63%, while the specificity was 97%. The predictive value of a positive test result was 70%, the figure being somewhat higher (75%) when the material was limited to milk samples without antibiotic residues. The predictive value of a negative test result was 95%. The LAL-test is considered to constitute a valuable cow-side test for the veterinary practitioner, aiding the selection of antibacterial drug of choice for the initial treatment of clinical mastitis.
在现场条件下对改良鲎试剂（LAL）奶牛现场检测法进行了评估。该检测法的原理是使检测成分与革兰氏阴性菌细胞壁中的内毒素之间的反应可视化。实际目的是检测患乳房炎牛奶中的此类细菌。采用LAL检测法对789个患有临床乳房炎的乳腺区的分泌物进行了检测。同时将乳腺区牛奶样本送去一家乳房炎微生物检测实验室。挪威三个兽医区的11名兽医进行了现场调查。在所有检测的牛奶样本中，LAL检测法与培养法的结果在93%的样本中一致，用kappa值衡量的一致性为0.63。该检测法检测革兰氏阴性菌的灵敏度为63%，而特异性为97%。阳性检测结果的预测值为70%，当材料仅限于无抗生素残留的牛奶样本时，该数值略高（75%）。阴性检测结果的预测值为95%。LAL检测法被认为是兽医从业者一项有价值的奶牛现场检测法，有助于为临床乳房炎的初始治疗选择首选抗菌药物。
