The conglutination phenomenon; the conglutinating complement absorption test in experimental glanders.

This study focuses on exploring the utility of the conglutinating complement absorption test for diagnosing glanders in horses using experimental models. The authors present their findings which demonstrate the test’s effectiveness in revealing the immune response to the disease in horses.

Introduction

• The authors start by noting the importance of a serological diagnosis for glanders in horses during the course of the war, which justified this research program. Glanders is a highly contagious bacterial disease that affects equines, primarily horses.
• The researchers aim to detail their investigations into the use of the conglutinating complement absorption test, a diagnostic test usually utilized in tandem with a haemolytic complement fixation test.
• Historically, the test’s major use was in studying the serological responses of mules and asses, especially in cases where these species’ sera were too anticomplementary for guinea-pig complement to be examined by the haemolytic complement fixation test.
• The authors acknowledge that there are differing opinions in the scientific community regarding the use of this diagnostic test, especially concerning its usefulness in diagnosing chronic glanders.

Methodology

• In the study, ponies were orally exposed to a culture of a bacterial strain called P. mallei, known to cause Glanders.
• The researchers then observed, for a span of 10 months, the fluctuations in complement fixing antibodies using conglutinating complement absorption and haemolytic complement fixation tests.
• Additionally, the authors also studied the effects of allergy tests on the level of blood antibodies.

Experimental Study

• A group of Dartmoor ponies were used for this investigation which started in 1943. Selected ponies were treated with virulent cultures of the P. mallei organism orally.
• The bacterial strain used in this experiment, marked K199, had previously been passaged through donkeys multiple times before. This is noted because unlike horses, donkeys usually fall prey to acute glanders post experimental infection.
• A set of control animals were also included in the study for comparison. Furthermore, ponies that had been treated with P. mallei in the previous year were also part of the study group.
• Lastly, a history of allergy tests, using methods like intra-dermo-palpebral test (i.p.p) and subcutaneous test (s.c) with mallein, were carried out on some of these ponies.