Evaluation of the bacterial endotoxin test for quantification of endotoxin contamination of porcine vaccines.

We investigated the application of the bacterial endotoxin test for the quantification of the endotoxin contamination of various commercial porcine vaccines. In endotoxin-spiked samples, Freund's complete adjuvant and aluminum hydroxide gel adjuvant failed to interfere with the results of the endotoxin test, and both recovery ratios were within the permissible range mentioned in the Japanese Pharmacopoeia. At the various dilutions tested, none of the adjuvants in commercial porcine vaccines caused noteworthy interference in the test. In addition, none of the 39 samples of porcine vaccines approved in Japan induced an interfering effect in the endotoxin test. Our findings suggest that the bacterial endotoxin test using endotoxin-specific Limulus amoebocyte lysate (LAL) can detect endotoxin contamination in commercial porcine vaccines containing either oil or aluminum adjuvants.

A silkworm larvae plasma test for detecting peptidoglycan in cerebrospinal fluid is useful for the diagnosis of bacterial meningitis.

The silkworm larvae plasma (SLP) test has been established based on a cascade reaction triggered by either peptidoglycan or (1, 3)-beta-D-glucan to produce melanin. We applied this test to the diagnosis of bacterial meningitis. Cerebrospinal fluid (CSF) obtained from patients with bacterial meningitis due to gram-positive bacteria, gram-negative bacteria, or fungi, showed positive reactions to the test. In contrast, CSF from patients with viral meningitis or noninfectious illnesses gave negative reactions. Therefore, this test seems to be useful for diagnosis of bacterial and fungal meningitis. When this test was used together with two types of limulus tests, an endotoxin-specific test, and a conventional test, meningitis was further characterized as gram-positive, gram-negative or fungal meningitis. The SLP test requires a computerized instrument for quantitative colorimetric measurement. A qualitative alternative of this test also can be accomplished by visually observing the darkening color. Thus, this method can be applied for simple and rapid diagnosis of meningitis.

Flow cytometric analysis of peripheral blood mononuclear cells induced by experimental endotoxemia in horse.

Cellular activation and functional cell surface markers were evaluated during experimentally-induced endotoxemia in healthy horses. Eight healthy adult horses were infused a low dose of endotoxin (lipopolysaccharide from Escherichia coli O26: B6, 30 ng/kg of body weight, IV) and five control horses were given an equivalent volume of sterile saline solution. Venous blood samples were collected for flow cytometric analysis of peripheral blood mononuclear cells (PBMCs) and to measure plasma endotoxin concentrations. Clinical signs of endotoxemia were recorded at 10, 20, 30, 40, 50 min, 1, 2, 3, 4, 8, 16, 24 and 48 hr after endotoxin or saline solution administration. Clinical findings characteristic of endotoxemia (tachycardia, tachypnea, increased rectal temperature, and leukopenia) occurred transiently in all horses administered endotoxin; however, plasma endotoxin concentrations were detectable in only 50% (4/8) of the endotoxin-infused horses. The percentage of CD4(+), CD5(+), and CD8(+) cells decreased while the percentage of CD14(+), IgM(+), and MHC class II(+) cells increased significantly after endotoxin infusion. Alterations in the immunophenotype of PBMCs from horses with experimentally-induced endotoxemia were associated with changes in vital signs, indicating that endotoxin altered the immuno balance.