STUDIES ON AN UNCOMPLICATED CORYZA OF THE DOMESTIC FOWL : IX. THE COOPERATIVE ACTION OF HEMOPHILUS GALLINARUM AND THE COCCOBACILLIFORM BODIES IN THE CORYZA OF RAPID ONSET AND LONG DURATION

Coccobacilliform bodies were regularly demonstrable, in addition to H. gallinarum, in exudate from birds infected with a passage strain of the coryza of rapid onset and long duration (type III). Both agents were present throughout the entire course of the disease. The characteristics of type III coryza were reproduced by injecting a mixture of the two agents. The behavior of each component was altered by the association, indicative of a synergistic relation. Evidence that the coccobacilliform bodies might occasionally develop in birds infected with H. gallinarum following transfer by indirect contact was also obtained. The combined action of the two infective agents adequately accounts for the etiology of this particular strain of type III coryza.     

STUDIES ON AN UNCOMPLICATED CORYZA OF THE DOMESTIC FOWL : V. A CORYZA OF SLOW ONSET

A strain of fowl coryza of slow onset was carried through 20 successive passages in susceptible birds over a period of approximately 19 months. During this period it retained its initial characteristics as did also a coryza of rapid onset which was similarly maintained. 88 per cent of 72 birds infected with the coryza of slow onset showed a nasal discharge after an incubation period of 12 days or more; the actual limits being 9 to 31 days. 98 per cent of 54 birds infected with the coryza of rapid onset showed a nasal discharge on the 1st or 2nd day after injection. The duration of both coryzas was prolonged. Bacteriological examination indicated that Hemophilus gallinarum which is invariably present in the nasal exudate of birds infected with the coryza of rapid onset is not associated with the coryza of slow onset.     

STUDIES ON AN UNCOMPLICATED CORYZA OF THE DOMESTIC FOWL : VI. COCCOBACILLIFORM BODIES IN BIRDS INFECTED WITH THE CORYZA OF SLOW ONSET

Minute coccobacilliform bodies have regularly been found in the nasal exudate of fowl infected both by injection and by contact with the coryza of slow onset. These bodies are commonly less than 0.5µ in diameter and are predominantly extracellular. They have consistently failed to grow in artificial media. They are held back by Berkefeld V filters which are impermeable to Hemophilus gallinarum but may pass through filters which are permeable to the test organism. The coccoid bodies are morphologically similar to a cultivable non-infective bacterium which may occasionally be isolated from exudate of the infected fowls.     

STUDIES ON ENDEMIC PNEUMONIA OF THE ALBINO RAT : I. THE TRANSMISSION OF A COMMUNICABLE DISEASE TO MICE FROM NATURALLY INFECTED RATS

A specific disease entity was established in white mice by the nasal instillation of lung and exudate suspensions from each of 14 adult albino rats affected with endemic pneumonia. The induced disease was characterized by pneumonia (96 per cent), otitis media (94 per cent), and rhinitis (30 per cent). It progressed slowly after an incubation period of 7 to 14 days and was attended by a variable mortality which reached 33 per cent in 22 weeks. Maintenance of the disease was regularly accomplished by direct transmission from mouse to mouse but only by the nasal route and only from the three foci of involvement. It was also transmissible by direct contact but required a prolonged period of exposure. The relation of the disease to infectious catarrh, which it closely resembles, is discussed.